DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, Shih-Ching; Lo, Shih-Yen; Graduate Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan

Research highlights: {yields} Lipid rafts are known to play an important role in virus entry and virus assembly of many viruses. {yields} However, HCV is the first example of the association of lipid raft with viral RNA replication. {yields} Our results in this manuscript demonstrate that purified HCV RCs with associated lipid raft membrane appeared as distinct particles of around 0.7 um under EM and AFM. {yields} Knockdown of proteins associated with lipid raft suppressed the HCV replication and reduced the number of these particles. {yields} To our knowledge, structures of HCV RCs were demonstrated at its first time inmore » this manuscript. -- Abstract: Hepatitis C viral RNA synthesis has been demonstrated to occur on a lipid raft membrane structure. Lipid raft membrane fraction purified by membrane flotation analysis was observed using transmission electron microscopy and atomic force microscopy. Particles around 0.7 um in size were found in lipid raft membrane fraction purified from hepatitis C virus (HCV) replicon but not their parental HuH7 cells. HCV NS5A protein was associated with these specialized particles. After several cycles of freezing-thawing, these particles would fuse into larger sizes up to 10 um. Knockdown of seven proteins associated with lipid raft (VAPA, COPG, RAB18, COMT, CDC42, DPP4, and KDELR2) of HCV replicon cells reduced the observed number of these particles and suppressed the HCV replication. Results in this study indicated that HCV replication complexes with associated lipid raft membrane form distinct particle structures of around 0.7 um as observed from transmission electron microscopy and atomic force microscopy.« less

DDX60L Is an Interferon-Stimulated Gene Product Restricting Hepatitis C Virus Replication in Cell Culture

PubMed Central

Grünvogel, Oliver; Esser-Nobis, Katharina; Reustle, Anna; Schult, Philipp; Müller, Birthe; Metz, Philippe; Trippler, Martin; Windisch, Marc P.; Frese, Michael; Binder, Marco; Fackler, Oliver; Bartenschlager, Ralf; Ruggieri, Alessia

2015-01-01

ABSTRACT All major types of interferon (IFN) efficiently inhibit hepatitis C virus (HCV) replication in vitro and in vivo. Remarkably, HCV replication is not sensitive to IFN-γ in the hepatoma cell line Huh6, despite an intact signaling pathway. We performed transcriptome analyses between Huh6 and Huh-7 cells to identify effector genes of the IFN-γ response and thereby identified the DExD/H box helicase DEAD box polypeptide 60-like (DDX60L) as a restriction factor of HCV replication. DDX60L and its homolog DEAD box polypeptide 60 (DDX60) were both induced upon viral infection and IFN treatment in primary human hepatocytes. However, exclusively DDX60L knockdown increased HCV replication in Huh-7 cells and rescued HCV replication from type II IFN as well as type I and III IFN treatment, suggesting that DDX60L is an important effector protein of the innate immune response against HCV. In contrast, we found no impact of DDX60L on replication of hepatitis A virus. DDX60L protein was detectable only upon strong ectopic overexpression, displayed a broad cytoplasmic distribution, but caused cytopathic effects under these conditions. DDX60L knockdown did not alter interferon-stimulated gene (ISG) induction after IFN treatment but inhibited HCV replication upon ectopic expression, suggesting that it is a direct effector of the innate immune response. It most likely inhibits viral RNA replication, since we found neither impact of DDX60L on translation or stability of HCV subgenomic replicons nor additional impact on assembly of infectious virus. Similar to DDX60, DDX60L had a moderate impact on RIG-I dependent activation of innate immunity, suggesting additional functions in the sensing of viral RNA. IMPORTANCE Interferons induce a plethora of interferon-stimulated genes (ISGs), which are our first line of defense against viral infections. In addition, IFNs have been used in antiviral therapy, in particular against the human pathogen hepatitis C virus (HCV); still, their mechanism of action is not well understood, since diverse, overlapping sets of antagonistic effector ISGs target viruses with different biologies. Our work identifies DDX60L as a novel factor that inhibits replication of HCV. DDX60L expression is regulated similarly to that of its homolog DDX60, but our data suggest that it has distinct functions, since we found no contribution of DDX60 in combatting HCV replication. The identification of novel components of the innate immune response contributes to a comprehensive understanding of the complex mechanisms governing antiviral defense. PMID:26269178

The Hepatitis C Virus-Induced Membranous Web and Associated Nuclear Transport Machinery Limit Access of Pattern Recognition Receptors to Viral Replication Sites

PubMed Central

Neufeldt, Christopher J.; Joyce, Michael A.; Van Buuren, Nicholas; Levin, Aviad; Kirkegaard, Karla; Gale Jr., Michael; Tyrrell, D. Lorne J.; Wozniak, Richard W.

2016-01-01

Hepatitis C virus (HCV) is a positive-strand RNA virus of the Flaviviridae family and a major cause of liver disease worldwide. HCV replicates in the cytoplasm, and the synthesis of viral proteins induces extensive rearrangements of host cell membranes producing structures, collectively termed the membranous web (MW). The MW contains the sites of viral replication and assembly, and we have identified distinct membrane fractions derived from HCV-infected cells that contain replication and assembly complexes enriched for viral RNA and infectious virus, respectively. The complex membrane structure of the MW is thought to protect the viral genome limiting its interactions with cytoplasmic pattern recognition receptors (PRRs) and thereby preventing activation of cellular innate immune responses. Here we show that PRRs, including RIG-I and MDA5, and ribosomes are excluded from viral replication and assembly centers within the MW. Furthermore, we present evidence that components of the nuclear transport machinery regulate access of proteins to MW compartments. We show that the restricted assess of RIG-I to the MW can be overcome by the addition of a nuclear localization signal sequence, and that expression of a NLS-RIG-I construct leads to increased immune activation and the inhibition of viral replication. PMID:26863439

Alterations in microRNA expression profile in HCV-infected hepatoma cells: Involvement of miR-491 in regulation of HCV replication via the PI3 kinase/Akt pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishida, Hisashi; Tatsumi, Tomohide; Hosui, Atsushi

2011-08-19

Highlights: {yields} HCV infection upregulated miR-192, -194, -215, downregulated miR-320, -491. {yields} Transfection of miR-192, -215, and -491 enhanced HCV replication. {yields} Transfection of miR-491 inhibited Akt phosphorylation. {yields} Akt inhibition could be responsible for augmentation of HCV replication by miR-491. -- Abstract: The aim of this study was to investigate the role of microRNA (miRNA) on hepatitis C virus (HCV) replication in hepatoma cells. Using miRNA array analysis, miR-192/miR-215, miR-194, miR-320, and miR-491 were identified as miRNAs whose expression levels were altered by HCV infection. Among them, miR-192/miR-215 and miR-491 were capable of enhancing replication of the HCV repliconmore » as well as HCV itself. HCV IRES activity or cell proliferation was not increased by forced expression of miR-192/miR-215 or miR-491. Investigation of signaling pathways revealed that miR-491 specifically suppressed the phosphoinositol-3 (PI3) kinase/Akt pathway. Under inhibition of PI3 kinase by LY294002, the suppressive effect of miR-491 on HCV replication was abolished, indicating that suppression of HCV replication by miR-491 was dependent on the PI3 kinase/Akt pathway. miRNAs altered by HCV infection would then affect HCV replication, which implies a complicated mechanism for regulating HCV replication. HCV-induced miRNA may be involved in changes in cellular properties including hepatocarcinogenesis.« less

The science of direct-acting antiviral and host-targeted agent therapy.

PubMed

Pawlotsky, Jean-Michel

2012-01-01

Direct-acting antiviral drugs targeting two major steps of the HCV life cycle, polyprotein processing and replication, and cyclophilin inhibitors, that target a host cell protein required to interact with the replication complex, have reached clinical development. In order to achieve a sustained virological response, that is, a cure of the HCV infection, it is necessary to shut down virus production, to maintain viral inhibition throughout treatment and to induce a significant, slower second-phase decline in HCV RNA levels that leads to definitive clearance of infected cells. Recent findings suggest that the interferon era is coming to an end in hepatitis C therapy and HCV infection can be cured by all-oral interferon-free treatment regimens within 12 to 24 weeks. Further results are awaited that will allow the establishment of an ideal first-line all-oral, interferon-free treatment regimen for patients with chronic HCV infection.

Saponin Inhibits Hepatitis C Virus Propagation by Up-regulating Suppressor of Cytokine Signaling 2

PubMed Central

Kang, Sang-Min; Min, Saehong; Son, Kidong; Lee, Han Sol; Park, Eun Mee; Ngo, Huong T. T.; Tran, Huong T. L.; Lim, Yun-Sook; Hwang, Soon B.

2012-01-01

Saponins are a group of naturally occurring plant glycosides which possess a wide range of pharmacological properties, including anti-tumorigenic and antiviral activities. To investigate whether saponin has anti-hepatitis C virus (HCV) activity, we examined the effect of saponin on HCV replication. HCV replication was efficiently inhibited at a concentration of 10 µg/ml of saponin in cell culture grown HCV (HCVcc)-infected cells. Inhibitory effect of saponin on HCV replication was verified by quantitative real-time PCR, reporter assay, and immunoblot analysis. In addition, saponin potentiated IFN-α-induced anti-HCV activity. Moreover, saponin exerted antiviral activity even in IFN-α resistant mutant HCVcc-infected cells. To investigate how cellular genes were regulated by saponin, we performed microarray analysis using HCVcc-infected cells. We demonstrated that suppressor of cytokine signaling 2 (SOCS2) protein level was distinctively increased by saponin, which in turn resulted in inhibition of HCV replication. We further showed that silencing of SOCS2 resurrected HCV replication and overexpression of SOCS2 suppressed HCV replication. These data imply that saponin inhibits HCV replication via SOCS2 signaling pathway. These findings suggest that saponin may be a potent therapeutic agent for HCV patients. PMID:22745742

Daclatasvir inhibits hepatitis C virus NS5A motility and hyper-accumulation of phosphoinositides

PubMed Central

Chukkapalli, Vineela; Berger, Kristi L.; Kelly, Sean M.; Thomas, Meryl; Deiters, Alexander; Randall, Glenn

2014-01-01

Combinations of direct-acting antivirals (DAAs) against the hepatitis C virus (HCV) have the potential to revolutionize the HCV therapeutic regime. An integral component of DAA combination therapies are HCV NS5A inhibitors. It has previously been proposed that NS5A DAAs inhibit two functions of NS5A: RNA replication and virion assembly. In this study, we characterize the impact of a prototype NS5A DAA, daclatasvir (DCV), on HCV replication compartment formation. DCV impaired HCV replicase localization and NS5A motility. In order to characterize the mechanism behind altered HCV replicase localization, we examined the impact of DCV on the interaction of NS5A with its essential cellular cofactor, phosphatidylinositol-4-kinase III α (PI4KA). We observed that DCV does not inhibit PI4KA directly, nor does it impair early events of the NS5A-PI4KA interaction that can occur when NS5A is expressed alone. NS5A functions that are unaffected by DCV include PI4KA binding, as determined by co-immunoprecipitation, and a basal accumulation of the PI4KA product, PI4P. However, DCV impairs late steps in PI4KA activation that requires NS5A expressed in the context of the HCV polyprotein. These NS5A functions include hyper-stimulation of PI4P levels and appropriate replication compartment formation. The data are most consistent with a model wherein DCV inhibits conformational changes in the NS5A protein or protein complex formations that occur in the context of HCV polyprotein expression and stimulate PI4P hyper-accumulation and replication compartment formation. PMID:25546252

Osteopontin Regulates Hepatitis C Virus (HCV) Replication and Assembly by Interacting with HCV Proteins and Lipid Droplets and by Binding to Receptors αVβ3 and CD44.

PubMed

Iqbal, Jawed; Sarkar-Dutta, Mehuli; McRae, Steven; Ramachandran, Akshaya; Kumar, Binod; Waris, Gulam

2018-07-01

Hepatitis C virus (HCV) replication and assembly occur at the specialized site of endoplasmic reticulum (ER) membranes and lipid droplets (LDs), respectively. Recently, several host proteins have been shown to be involved in HCV replication and assembly. In the present study, we demonstrated the important relationship among osteopontin (OPN), the ER, and LDs. OPN is a secreted phosphoprotein, and overexpression of OPN in hepatocellular carcinoma (HCC) tissue can lead to invasion and metastasis. OPN expression is also enhanced in HCV-associated HCC. Our recent studies have demonstrated the induction, proteolytic cleavage, and secretion of OPN in response to HCV infection. We also defined the critical role of secreted OPN in human hepatoma cell migration and invasion through binding to receptors integrin αVβ3 and CD44. However, the role of HCV-induced OPN in the HCV life cycle has not been elucidated. In this study, we showed a significant reduction in HCV replication, assembly, and infectivity in HCV-infected cells transfected with small interfering RNA (siRNA) against OPN, αVβ3, and CD44. We also observed the association of endogenous OPN with HCV proteins (NS3, NS5A, NS4A/B, NS5B, and core). Confocal microscopy revealed the colocalization of OPN with HCV NS5A and core in the ER and LDs, indicating a possible role for OPN in HCV replication and assembly. Interestingly, the secreted OPN activated HCV replication, infectivity, and assembly through binding to αVβ3 and CD44. Collectively, these observations provide evidence that HCV-induced OPN is critical for HCV replication and assembly. IMPORTANCE Recently, our studies uncovered the critical role of HCV-induced endogenous and secreted OPN in migration and invasion of hepatocytes. However, the role of OPN in the HCV life cycle has not been elucidated. In this study, we investigated the importance of OPN in HCV replication and assembly. We demonstrated that endogenous OPN associates with HCV NS3, NS5A, NS5B, and core proteins, which are in close proximity to the ER and LDs. Moreover, we showed that the interactions of secreted OPN with cell surface receptors αVβ3 and CD44 are critical for HCV replication and assembly. These observations provide evidence that HCV-induced endogenous and secreted OPN play pivotal roles in HCV replication and assembly in HCV-infected cells. Taken together, our findings clearly demonstrate that targeting OPN may provide opportunities for therapeutic intervention of HCV pathogenesis. Copyright © 2018 American Society for Microbiology.

Rad51 Interacts with Non-structural 3 Protein of Hepatitis C Virus and Regulates Viral Production

PubMed Central

Son, Kidong; Nguyen, Tram T. T.; Choi, Jae-Woong; Pham, Long V.; Luong, Trang T. D.; Lim, Yun-Sook; Hwang, Soon B.

2017-01-01

Hepatitis C virus (HCV) is a leading cause of chronic liver disease affecting over 170 million people worldwide. Chronic infection with HCV progresses to liver fibrosis, cirrhosis, and hepatocellular carcinoma. HCV exploits host cellular factors for viral propagation. To investigate the cellular factors required for HCV propagation, we screened a siRNA library targeting human cell cycle genes using cell culture grown HCV-infected cells. In the present study, we selected and characterized a gene encoding Rad51. Rad51, a member of a conserved recombinase family, is an essential factor for homologous recombination and repair of double-strand DNA breaks. We demonstrated that siRNA-mediated knockdown of Rad51 significantly inhibited HCV propagation without affecting HCV RNA replication. Silencing of Rad51 impaired secretion of infectious HCV particles and thus intracellular viruses were accumulated. We showed that HCV NS3 specifically interacted with Rad51 and accumulated Rad51 in the cytosol. Furthermore, Rad51 was coprecipitated with NS3 and HCV RNA. By employing membrane flotation and protease protection assays, we also demonstrated that Rad51 was co-fractionated with HCV NS3 on the lipid raft. These data indicate that Rad51 may be a component of the HCV RNA replication complex. Collectively, these data suggest that HCV may exploit cellular Rad51 to promote viral propagation and thus Rad51 may be a potential therapeutic target for HCV. PMID:28729862

Active RNA replication of hepatitis C virus downregulates CD81 expression.

PubMed

Ke, Po-Yuan; Chen, Steve S-L

2013-01-01

So far how hepatitis C virus (HCV) replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS) protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp) infection and downregulated cell surface level of CD81, a critical HCV entry (co)receptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81.

Active RNA Replication of Hepatitis C Virus Downregulates CD81 Expression

PubMed Central

Ke, Po-Yuan; Chen, Steve S.-L.

2013-01-01

So far how hepatitis C virus (HCV) replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS) protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp) infection and downregulated cell surface level of CD81, a critical HCV entry (co)receptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81. PMID:23349980

Comprehensive Analysis of the Effects of Ordinary Nutrients on Hepatitis C Virus RNA Replication in Cell Culture▿

PubMed Central

Yano, Masahiko; Ikeda, Masanori; Abe, Ken-ichi; Dansako, Hiromichi; Ohkoshi, Shogo; Aoyagi, Yutaka; Kato, Nobuyuki

2007-01-01

To date, only a limited number of studies have reported finding an influence of ordinary nutrients on hepatitis C virus (HCV) RNA replication. However, the effects of other nutrients on HCV RNA replication remain largely unknown. We recently developed a reporter assay system for genome-length HCV RNA replication in hepatoma-derived HuH-7 cells (OR6). Here, using this OR6 assay system, we comprehensively examined 46 nutrients from four nutrient groups: vitamins, amino acids, fatty acids, and salts. We found that three nutrients—β-carotene, vitamin D2, and linoleic acid—inhibited HCV RNA replication and that their combination caused additive and/or synergistic effects on HCV RNA replication. In addition, combined treatment with each of the three nutrients and interferon alpha or beta or fluvastatin inhibited HCV RNA replication in an additive manner, while combined treatment with cyclosporine synergistically inhibited HCV RNA replication. In contrast, we found that vitamin E enhanced HCV RNA replication and negated the effects of the three anti-HCV nutrients and cyclosporine but not those of interferon or fluvastatin. These results will provide useful information for the treatment of chronic hepatitis C patients who also take anti-HCV nutrients as an adjunctive therapy in combination with interferon. In conclusion, among the ordinary nutrients tested, β-carotene, vitamin D2, and linoleic acid possessed anti-HCV activity in a cell culture system, and these nutrients are therefore considered to be potential candidates for enhancing the effects of interferon therapy. PMID:17420205

Inhibition of hepatitis C virus replication through adenosine monophosphate-activated protein kinase-dependent and -independent pathways.

PubMed

Nakashima, Kenji; Takeuchi, Kenji; Chihara, Kazuyasu; Hotta, Hak; Sada, Kiyonao

2011-11-01

Persistent infection with hepatitis C virus (HCV) is closely correlated with type 2 diabetes. In this study, replication of HCV at different glucose concentrations was investigated by using J6/JFH1-derived cell-adapted HCV in Huh-7.5 cells and the mechanism of regulation of HCV replication by AMP-activated protein kinase (AMPK) as an energy sensor of the cell analyzed. Reducing the glucose concentration in the cell culture medium from 4.5 to 1.0 g/L resulted in suppression of HCV replication, along with activation of AMPK. Whereas treatment of cells with AMPK activator 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) suppressed HCV replication, compound C, a specific AMPK inhibitor, prevented AICAR's effect, suggesting that AICAR suppresses the replication of HCV by activating AMPK in Huh-7.5 cells. In contrast, compound C induced further suppression of HCV replication when the cells were cultured in low glucose concentrations or with metformin. These results suggest that low glucose concentrations and metformin have anti-HCV effects independently of AMPK activation. © 2011 The Societies and Blackwell Publishing Asia Pty Ltd.

Characterization of miR-122-independent propagation of HCV

PubMed Central

Motooka, Daisuke; Nakamura, Shota; Yamamoto, Satomi; Mori, Hiroyuki; Sato, Asuka; Uemura, Kentaro; Fauzyah, Yuzy; Suda, Takahiro; Nishio, Akira; Hmwe, Su Su; Okamoto, Toru; Tatsumi, Tomohide; Takehara, Tetsuo; Chayama, Kazuaki; Wakita, Takaji; Koike, Kazuhiko

2017-01-01

miR-122, a liver-specific microRNA, is one of the determinants for liver tropism of hepatitis C virus (HCV) infection. Although miR-122 is required for efficient propagation of HCV, we have previously shown that HCV replicates at a low rate in miR-122-deficient cells, suggesting that HCV-RNA is capable of propagating in an miR-122-independent manner. We herein investigated the roles of miR-122 in both the replication of HCV-RNA and the production of infectious particles by using miR-122-knockout Huh7 (Huh7-122KO) cells. A slight increase of intracellular HCV-RNA levels and infectious titers in the culture supernatants was observed in Huh7-122KO cells upon infection with HCV. Moreover, after serial passages of HCV in miR-122-knockout Huh7.5.1 cells, we obtained an adaptive mutant, HCV122KO, possessing G28A substitution in the 5’UTR of the HCV genotype 2a JFH1 genome, and this mutant may help to enhance replication complex formation, a possibility supported by polysome analysis. We also found the introduction of adaptive mutation around miR-122 binding site in the genotype 1b/2a chimeric virus, which originally had an adenine at the nucleotide position 29. HCV122KO exhibited efficient RNA replication in miR-122-knockout cells and non-hepatic cells without exogenous expression of miR-122. Competition assay revealed that the G28A mutant was dominant in the absence of miR-122, but its effects were equivalent to those of the wild type in the presence of miR-122, suggesting that the G28A mutation does not confer an advantage for propagation in miR-122-rich hepatocytes. These observations may explain the clinical finding that the positive rate of G28A mutation was higher in miR-122-deficient PBMCs than in the patient serum, which mainly included the hepatocyte-derived virus from HCV-genotype-2a patients. These results suggest that the emergence of HCV mutants that can propagate in non-hepatic cells in an miR-122-independent manner may participate in the induction of extrahepatic manifestations in chronic hepatitis C patients. PMID:28494029

Betulinic acid exerts anti-hepatitis C virus activity via the suppression of NF-κB- and MAPK-ERK1/2-mediated COX-2 expression.

PubMed

Lin, Chun-Kuang; Tseng, Chin-Kai; Chen, Kai-Hsun; Wu, Shih-Hsiung; Liaw, Chih-Chuang; Lee, Jin-Ching

2015-06-23

This study was designed to evaluate the effect of betulinic acid (BA), extracted from Avicennia marina, on the replication of hepatitis C virus (HCV) and to investigate the mechanism of this BA-mediated anti-HCV activity. HCV replicon and infectious systems were used to evaluate the anti-HCV activity of BA. Exogenous COX-2 or knock-down of COX-2 expression was used to investigate the role of COX-2 in the anti-HCV activity of BA. The effects of BA on the phosphorylation of NF-κB and on kinases in the MAPK signalling pathway were determined. The anti-HCV activity of BA in combination with other HCV inhibitors was also determined to assess its use as an anti-HCV supplement. BA inhibited HCV replication in both Ava5 replicon cells and in a cell culture-derived infectious HCV particle system. Treatment with a combination of BA and IFN-α, the protease inhibitor telaprevir or the NS5B polymerase inhibitor sofosbuvir resulted in the synergistic suppression of HCV RNA replication. Exogenous overexpression of COX-2 gradually attenuated the inhibitory effect of BA on HCV replication, suggesting that BA reduces HCV replication by suppressing the expression of COX-2. In particular, BA down-regulated HCV-induced COX-2 expression by reducing the phosphorylation of NF-κB and ERK1/2 of the MAPK signalling pathway. BA inhibits HCV replication by suppressing the NF-κB- and ERK1/2-mediated COX-2 pathway and may serve as a promising compound for drug development or as a potential supplement for use in the treatment of HCV-infected patients. © 2015 The British Pharmacological Society.

Hepatitis A virus infection suppresses hepatitis C virus replication and may lead to clearance of HCV.

PubMed

Deterding, Katja; Tegtmeyer, Björn; Cornberg, Markus; Hadem, Johannes; Potthoff, Andrej; Böker, Klaus H W; Tillmann, Hans L; Manns, Michael P; Wedemeyer, Heiner

2006-12-01

The significance of hepatitis A virus (HAV) super-infection in patients with chronic hepatitis C had been a matter of debate. While some studies suggested an incidence of fulminant hepatitis A of up to 35%, this could not be confirmed by others. We identified 17 anti-HCV-positive patients with acute hepatitis A from a cohort of 3170 anti-HCV-positive patients recruited at a single center over a period of 12 years. Importantly, none of the anti-HCV-positive patients had a fulminant course of hepatitis A. HCV-RNA was detected by PCR in 84% of the anti-HCV-positive/anti-HAV-IgM-negative patients but only in 65% of anti-HCV-positive patients with acute hepatitis A (p=0.03), indicating suppression of HCV replication during hepatitis A. Previous HAV infection had no effect on HCV replication. After recovery from hepatitis A, an increased HCV replication could be demonstrated for 6 out of 9 patients with serial quantitative HCV-RNA values available while 2 patients remained HCV-RNA negative after clearance of HAV throughout follow-up of at least 2 years. HAV super-infection is associated with decreased HCV-RNA replication which may lead to recovery from HCV in some individuals. Fulminant hepatitis A is not frequent in patients with chronic hepatitis C recruited at a tertiary referral center.

Augmentation of DHCR24 expression by hepatitis C virus infection facilitates viral replication in hepatocytes.

PubMed

Takano, Takashi; Tsukiyama-Kohara, Kyoko; Hayashi, Masahiro; Hirata, Yuichi; Satoh, Masaaki; Tokunaga, Yuko; Tateno, Chise; Hayashi, Yukiko; Hishima, Tsunekazu; Funata, Nobuaki; Sudoh, Masayuki; Kohara, Michinori

2011-09-01

We characterized the role of 24-dehydrocholesterol reductase (DHCR24) in hepatitis C virus infection (HCV). DHCR24 is a cholesterol biosynthetic enzyme and cholesterol is a major component of lipid rafts, which is reported to play an important role in HCV replication. Therefore, we examined the potential of DHCR24 as a target for novel HCV therapeutic agents. We examined DHCR24 expression in human hepatocytes in both the livers of HCV-infected patients and those of chimeric mice with human hepatocytes. We targeted DHCR24 with siRNA and U18666A which is an inhibitor of both DHCR24 and cholesterol synthesis. We measured the level of HCV replication in these HCV replicon cell lines and HCV infected cells. U18666A was administrated into chimeric mice with humanized liver, and anti-viral effects were assessed. Expression of DHCR24 was induced by HCV infection in human hepatocytes in vitro, and in human hepatocytes of chimeric mouse liver. Silencing of DHCR24 by siRNA decreased HCV replication in replicon cell lines and HCV JFH-1 strain-infected cells. Treatment with U18666A suppressed HCV replication in the replicon cell lines. Moreover, to evaluate the anti-viral effect of U18666A in vivo, we administrated U18666A with or without pegylated interferon to chimeric mice and observed an inhibitory effect of U18666A on HCV infection and a synergistic effect with interferon. DHCR24 is an essential host factor which augmented its expression by HCV infection, and plays a significant role in HCV replication. DHCR24 may serve as a novel anti-HCV drug target. Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Isolation and Characterization of Highly Replicable Hepatitis C Virus Genotype 1a Strain HCV-RMT

PubMed Central

Arai, Masaaki; Tokunaga, Yuko; Takagi, Asako; Tobita, Yoshimi; Hirata, Yuichi; Ishida, Yuji; Tateno, Chise; Kohara, Michinori

2013-01-01

Multiple genotype 1a clones have been reported, including the very first hepatitis C virus (HCV) clone called H77. The replication ability of some of these clones has been confirmed in vitro and in vivo, although this ability is somehow compromised. We now report a newly isolated genotype 1a clone, designated HCV-RMT, which has the ability to replicate efficiently in patients, chimeric mice with humanized liver, and cultured cells. An authentic subgenomic replicon cell line was established from the HCV-RMT sequence with spontaneous introduction of three adaptive mutations, which were later confirmed to be responsible for efficient replication in HuH-7 cells as both subgenomic replicon RNA and viral genome RNA. Following transfection, the HCV-RMT RNA genome with three adaptive mutations was maintained for more than 2 months in HuH-7 cells. One clone selected from the transfected cells had a high copy number, and its supernatant could infect naïve HuH-7 cells. Direct injection of wild-type HCV-RMT RNA into the liver of chimeric mice with humanized liver resulted in vigorous replication, similar to inoculation with the parental patient’s serum. A study of virus replication using HCV-RMT derivatives with various combinations of adaptive mutations revealed a clear inversely proportional relationship between in vitro and in vivo replication abilities. Thus, we suggest that HCV-RMT and its derivatives are important tools for HCV genotype 1a research and for determining the mechanism of HCV replication in vitro and in vivo. PMID:24358200

Isolation and characterization of highly replicable hepatitis C virus genotype 1a strain HCV-RMT.

PubMed

Arai, Masaaki; Tokunaga, Yuko; Takagi, Asako; Tobita, Yoshimi; Hirata, Yuichi; Ishida, Yuji; Tateno, Chise; Kohara, Michinori

2013-01-01

Multiple genotype 1a clones have been reported, including the very first hepatitis C virus (HCV) clone called H77. The replication ability of some of these clones has been confirmed in vitro and in vivo, although this ability is somehow compromised. We now report a newly isolated genotype 1a clone, designated HCV-RMT, which has the ability to replicate efficiently in patients, chimeric mice with humanized liver, and cultured cells. An authentic subgenomic replicon cell line was established from the HCV-RMT sequence with spontaneous introduction of three adaptive mutations, which were later confirmed to be responsible for efficient replication in HuH-7 cells as both subgenomic replicon RNA and viral genome RNA. Following transfection, the HCV-RMT RNA genome with three adaptive mutations was maintained for more than 2 months in HuH-7 cells. One clone selected from the transfected cells had a high copy number, and its supernatant could infect naïve HuH-7 cells. Direct injection of wild-type HCV-RMT RNA into the liver of chimeric mice with humanized liver resulted in vigorous replication, similar to inoculation with the parental patient's serum. A study of virus replication using HCV-RMT derivatives with various combinations of adaptive mutations revealed a clear inversely proportional relationship between in vitro and in vivo replication abilities. Thus, we suggest that HCV-RMT and its derivatives are important tools for HCV genotype 1a research and for determining the mechanism of HCV replication in vitro and in vivo.

Viral replication. Structural basis for RNA replication by the hepatitis C virus polymerase.

PubMed

Appleby, Todd C; Perry, Jason K; Murakami, Eisuke; Barauskas, Ona; Feng, Joy; Cho, Aesop; Fox, David; Wetmore, Diana R; McGrath, Mary E; Ray, Adrian S; Sofia, Michael J; Swaminathan, S; Edwards, Thomas E

2015-02-13

Nucleotide analog inhibitors have shown clinical success in the treatment of hepatitis C virus (HCV) infection, despite an incomplete mechanistic understanding of NS5B, the viral RNA-dependent RNA polymerase. Here we study the details of HCV RNA replication by determining crystal structures of stalled polymerase ternary complexes with enzymes, RNA templates, RNA primers, incoming nucleotides, and catalytic metal ions during both primed initiation and elongation of RNA synthesis. Our analysis revealed that highly conserved active-site residues in NS5B position the primer for in-line attack on the incoming nucleotide. A β loop and a C-terminal membrane-anchoring linker occlude the active-site cavity in the apo state, retract in the primed initiation assembly to enforce replication of the HCV genome from the 3' terminus, and vacate the active-site cavity during elongation. We investigated the incorporation of nucleotide analog inhibitors, including the clinically active metabolite formed by sofosbuvir, to elucidate key molecular interactions in the active site. Copyright © 2015, American Association for the Advancement of Science.

CD40 inhibits replication of hepatitis C virus in primary human hepatocytes by c-Jun N terminal kinase activation independent from the interferon pathway.

PubMed

Rau, Sibylle J; Hildt, Eberhard; Himmelsbach, Kiyoshi; Thimme, Robert; Wakita, Takaji; Blum, Hubert E; Fischer, Richard

2013-01-01

CD40, a member of the tumor necrosis factor receptor family, and its ligand, CD40L (CD154), are important regulators of the antiviral immune response. CD40L is up-regulated on lymphocytes and CD40 on hepatocytes during infection with hepatitis C virus (HCV); we investigated the role of CD40 signaling during HCV replication in hepatocytes. Viral replication was studied in primary human hepatocytes (PHH) and Huh7.5 cells using the infectious HCV Japanese fulminate hepatitis 1 isolate (JFH1) culture system, and in coculture with HCV antigen-specific CD8+ T cells. CD40L rapidly and transiently inhibits expression of the HCV nonstructural proteins NS3 and NS5A as well as HCV structural proteins core and E2 in Huh7.5 cells. Similarly, CD40L prevented replication of HCV in PHH, in synergy with interferon (IFN)-alpha. In Huh7.5 cells with replicating HCV, CD40L prevented production of infectious viral particles. When HCV antigen-specific CD8+ T cells were cocultured with HLA-A2-expressing Huh7 cells that had replicating virus, the T cells became activated, up-regulated CD40L, and inhibited HCV replication. Inhibition of CD40L partially prevented the antiviral activity of the CD8+ T cells. The antiviral effect of CD40L required activation of c-Jun N terminal kinases (JNK)1/2, but not induction of apoptosis or the JAK/STAT pathway that is necessary for the antiviral effects of IFNs. CD40 inhibits HCV replication by a novel, innate immune mechanism. This pathway might mediate viral clearance, and disruptions might be involved in the pathogenesis of HCV infection. Copyright © 2012 American Association for the Study of Liver Diseases.

Matrix Conditions and KLF2-Dependent Induction of Heme Oxygenase-1 Modulate Inhibition of HCV Replication by Fluvastatin

PubMed Central

Singethan, Katrin; Sirma, Hüseyin; Keller, Amelie Dorothea; Rosal, Sergio René Perez; Schrader, Jörg; Loscher, Christine; Volz, Tassilo; Bartenschlager, Ralf; Lohmann, Volker; Protzer, Ulrike; Dandri, Maura; Lohse, Ansgar W.; Tiegs, Gisa; Sass, Gabriele

2014-01-01

Background & Aims HMG-CoA-reductase-inhibitors (statins) have been shown to interfere with HCV replication in vitro. We investigated the mechanism, requirements and contribution of heme oxygenase-1(HO-1)-induction by statins to interference with HCV replication. Methods HO-1-induction by fluva-, simva-, rosuva-, atorva- or pravastatin was correlated to HCV replication, using non-infectious replicon systems as well as the infectious cell culture system. The mechanism of HO-1-induction by statins as well as its relevance for interference with HCV replication was investigated using transient or permanent knockdown cell lines. Polyacrylamide(PAA) gels of different density degrees or the Rho-kinase-inhibitor Hydroxyfasudil were used in order to mimic matrix conditions corresponding to normal versus fibrotic liver tissue. Results All statins used, except pravastatin, decreased HCV replication and induced HO-1 expression, as well as interferon response in vitro. HO-1-induction was mediated by reduction of Bach1 expression and induction of the Nuclear factor (erythroid-derived 2)-like 2 (NRF2) cofactor Krueppel-like factor 2 (KLF2). Knockdown of KLF2 or HO-1 abrogated effects of statins on HCV replication. HO-1-induction and anti-viral effects of statins were more pronounced under cell culture conditions mimicking advanced stages of liver disease. Conclusions Statin-mediated effects on HCV replication seem to require HO-1-induction, which is more pronounced in a microenvironment resembling fibrotic liver tissue. This implicates that certain statins might be especially useful to support HCV therapy of patients at advanced stages of liver disease. PMID:24801208

Synthetic lipophilic antioxidant BO-653 suppresses HCV replication.

PubMed

Yasui, Fumihiko; Sudoh, Masayuki; Arai, Masaaki; Kohara, Michinori

2013-02-01

The influence of the intracellular redox state on the hepatitis C virus (HCV) life cycle is poorly understood. This study demonstrated the anti-HCV activity of 2,3-dihydro-5-hydroxy-2,2-dipentyl-4,6-di-tert-butylbenzofuran (BO-653), a synthetic lipophilic antioxidant, and examined whether BO-653's antioxidant activity is integral to its anti-HCV activity. The anti-HCV activity of BO-653 was investigated in HuH-7 cells bearing an HCV subgenomic replicon (FLR3-1 cells) and in HuH-7 cells infected persistently with HCV (RMT-tri cells). BO-653 inhibition of HCV replication was also compared with that of several hydrophilic and lipophilic antioxidants. BO-653 suppressed HCV replication in FLR3-1 and RMT-tri cells in a concentration-dependent manner. The lipophilic antioxidants had stronger anti-HCV activities than the hydrophilic antioxidants, and BO-653 displayed the strongest anti-HCV activity of all the antioxidants examined. Therefore, the anti-HCV activity of BO-653 was examined in chimeric mice harboring human hepatocytes infected with HCV. The combination treatment of BO-653 and polyethylene glycol-conjugated interferon-α (PEG-IFN) decreased serum HCV RNA titer more than that seen with PEG-IFN alone. These findings suggest that both the lipophilic property and the antioxidant activity of BO-653 play an important role in the inhibition of HCV replication. Copyright © 2012 Wiley Periodicals, Inc.

SUMO1 depletion prevents lipid droplet accumulation and HCV replication.

PubMed

Akil, Abdellah; Wedeh, Ghaith; Zahid Mustafa, Mohammad; Gassama-Diagne, Ama

2016-01-01

Infection by hepatitis C virus (HCV) is a major public-health problem. Chronic infection often leads to cirrhosis, steatosis, and hepatocellular carcinoma. The life cycle of HCV depends on the host cell machinery and involves intimate interaction between viral and host proteins. However, the role of host proteins in the life cycle of HCV remains poorly understood. Here, we identify the small ubiquitin-related modifier (SUMO1) as a key host factor required for HCV replication. We performed a series of cell biology and biochemistry experiments using the HCV JFH-1 (Japanese fulminate hepatitis 1) genotype 2a strain, which produces infectious particles and recapitulates all the steps of the HCV life cycle. We observed that SUMO1 is upregulated in Huh7.5 infected cells. Reciprocally, SUMO1 was found to regulate the expression of viral core protein. Moreover, knockdown of SUMO1 using specific siRNA influenced the accumulation of lipid droplets and reduced HCV replication as measured by qRT-PCR. Thus, we identify SUMO1 as a key host factor required for HCV replication. To our knowledge, this is the first report showing that SUMO1 regulates lipid droplets in the context of viral infection. Our report provides a meaningful insight into how HCV replicates and interacts with host proteins and is of significant importance for the field of HCV and RNA viruses.

Host apolipoprotein B messenger RNA-editing enzyme catalytic polypeptide-like 3G is an innate defensive factor and drug target against hepatitis C virus.

PubMed

Peng, Zong-Gen; Zhao, Zhi-Yun; Li, Yan-Ping; Wang, Yu-Ping; Hao, Lan-Hu; Fan, Bo; Li, Yu-Huan; Wang, Yue-Ming; Shan, Yong-Qiang; Han, Yan-Xing; Zhu, Yan-Ping; Li, Jian-Rui; You, Xue-Fu; Li, Zhuo-Rong; Jiang, Jian-Dong

2011-04-01

Host cellular factor apolipoprotein B messenger RNA (mRNA)-editing enzyme catalytic polypeptide-like 3G (hA3G) is a cytidine deaminase that inhibits a group of viruses including human immunodeficiency virus-1 (HIV-1). In the continuation of our research on hA3G, we found that hA3G stabilizing compounds significantly inhibited hepatitis C virus (HCV) replication. Therefore, this study investigated the role of hA3G in HCV replication. Introduction of external hA3G into HCV-infected Huh7.5 human hepatocytes inhibited HCV replication; knockdown of endogenous hA3G enhanced HCV replication. Exogenous HIV-1 virion infectivity factor (Vif) decreased intracellular hA3G and therefore enhanced HCV proliferation, suggesting that the presence of Vif might be an explanation for the HIV-1/HCV coinfection often observed in HIV-1(+) individuals. Treatment of the HCV-infected Huh7.5 cells with RN-5 or IMB-26, two known hA3G stabilizing compounds, increased intracellular hA3G and accordingly inhibited HCV replication. The compounds inhibit HCV through increasing the level of hA3G incorporated into HCV particles, but not through inhibiting HCV enzymes. However, G/A hypermutation in the HCV genome were not detected, suggesting a new antiviral mechanism of hA3G in HCV, different from that in HIV-1. Stabilization of hA3G by RN-5 was safe in vivo. hA3G appears to be a cellular restrict factor against HCV and could be a potential target for drug discovery. 2011 American Association for the Study of Liver Diseases.

Structure of Hepatitis C Virus Polymerase in Complex with Primer-Template RNA

PubMed Central

Murakami, Eisuke; Lam, Angela M.; Grice, Rena L.; Du, Jinfa; Sofia, Michael J.; Furman, Philip A.; Otto, Michael J.

2012-01-01

The replication of the hepatitis C viral (HCV) genome is accomplished by the NS5B RNA-dependent RNA polymerase (RdRp), for which mechanistic understanding and structure-guided drug design efforts have been hampered by its propensity to crystallize in a closed, polymerization-incompetent state. The removal of an autoinhibitory β-hairpin loop from genotype 2a HCV NS5B increases de novo RNA synthesis by >100-fold, promotes RNA binding, and facilitated the determination of the first crystallographic structures of HCV polymerase in complex with RNA primer-template pairs. These crystal structures demonstrate the structural realignment required for primer-template recognition and elongation, provide new insights into HCV RNA synthesis at the molecular level, and may prove useful in the structure-based design of novel antiviral compounds. Additionally, our approach for obtaining the RNA primer-template-bound structure of HCV polymerase may be generally applicable to solving RNA-bound complexes for other viral RdRps that contain similar regulatory β-hairpin loops, including bovine viral diarrhea virus, dengue virus, and West Nile virus. PMID:22496223

Infection with hepatitis C virus depends on TACSTD2, a regulator of claudin-1 and occludin highly downregulated in hepatocellular carcinoma

PubMed Central

Alayli, Farah; Melis, Marta; Kabat, Juraj; Pomerenke, Anna; Altan-Bonnet, Nihal; Zamboni, Fausto; Emerson, Suzanne U.

2018-01-01

Entry of hepatitis C virus (HCV) into hepatocytes is a complex process that involves numerous cellular factors, including the scavenger receptor class B type 1 (SR-B1), the tetraspanin CD81, and the tight junction (TJ) proteins claudin-1 (CLDN1) and occludin (OCLN). Despite expression of all known HCV-entry factors, in vitro models based on hepatoma cell lines do not fully reproduce the in vivo susceptibility of liver cells to primary HCV isolates, implying the existence of additional host factors which are critical for HCV entry and/or replication. Likewise, HCV replication is severely impaired within hepatocellular carcinoma (HCC) tissue in vivo, but the mechanisms responsible for this restriction are presently unknown. Here, we identify tumor-associated calcium signal transducer 2 (TACSTD2), one of the most downregulated genes in primary HCC tissue, as a host factor that interacts with CLDN1 and OCLN and regulates their cellular localization. TACSTD2 gene silencing disrupts the typical linear distribution of CLDN1 and OCLN along the cellular membrane in both hepatoma cells and primary human hepatocytes, recapitulating the pattern observed in vivo in primary HCC tissue. Mechanistic studies suggest that TACSTD2 is involved in the phosphorylation of CLDN1 and OCLN, which is required for their proper cellular localization. Silencing of TACSTD2 dramatically inhibits HCV infection with a pan-genotype effect that occurs at the level of viral entry. Our study identifies TACSTD2 as a novel regulator of two major HCV-entry factors, CLDN1 and OCLN, which is strongly downregulated in malignant hepatocytes. These results provide new insights into the complex process of HCV entry into hepatocytes and may assist in the development of more efficient cellular systems for HCV propagation in vitro. PMID:29538454

Diminished viral replication and compartmentalization of hepatitis C virus in hepatocellular carcinoma tissue.

PubMed

Harouaka, Djamila; Engle, Ronald E; Wollenberg, Kurt; Diaz, Giacomo; Tice, Ashley B; Zamboni, Fausto; Govindarajan, Sugantha; Alter, Harvey; Kleiner, David E; Farci, Patrizia

2016-02-02

Analysis of hepatitis C virus (HCV) replication and quasispecies distribution within the tumor of patients with HCV-associated hepatocellular carcinoma (HCC) can provide insight into the role of HCV in hepatocarcinogenesis and, conversely, the effect of HCC on the HCV lifecycle. In a comprehensive study of serum and multiple liver specimens from patients with HCC who underwent liver transplantation, we found a sharp and significant decrease in HCV RNA in the tumor compared with surrounding nontumorous tissues, but found no differences in multiple areas of control non-HCC cirrhotic livers. Diminished HCV replication was not associated with changes in miR-122 expression. HCV genetic diversity was significantly higher in livers containing HCC compared with control non-HCC cirrhotic livers. Tracking of individual variants demonstrated changes in the viral population between tumorous and nontumorous areas, the extent of which correlated with the decline in HCV RNA, suggesting HCV compartmentalization within the tumor. In contrast, compartmentalization was not observed between nontumorous areas and serum, or in controls between different areas of the cirrhotic liver or between liver and serum. Our findings indicate that HCV replication within the tumor is restricted and compartmentalized, suggesting segregation of specific viral variants in malignant hepatocytes.

Hepatitis C Virus Induces the Localization of Lipid Rafts to Autophagosomes for Its RNA Replication

PubMed Central

Kim, Ja Yeon; Wang, Linya; Lee, Jiyoung

2017-01-01

ABSTRACT Autophagy plays important roles in maintaining cellular homeostasis. It uses double- or multiple-membrane vesicles termed autophagosomes to remove protein aggregates and damaged organelles from the cytoplasm for recycling. Hepatitis C virus (HCV) has been shown to induce autophagy to enhance its own replication. Here we describe a procedure that combines membrane flotation and affinity chromatography for the purification of autophagosomes from cells that harbor an HCV subgenomic RNA replicon. The purified autophagosomes had double- or multiple-membrane structures with a diameter ranging from 200 nm to 600 nm. The analysis of proteins associated with HCV-induced autophagosomes by proteomics led to the identification of HCV nonstructural proteins as well as proteins involved in membrane trafficking. Notably, caveolin-1, caveolin-2, and annexin A2, which are proteins associated with lipid rafts, were also identified. The association of lipid rafts with HCV-induced autophagosomes was confirmed by Western blotting, immunofluorescence microscopy, and immunoelectron microscopy. Their association with autophagosomes was also confirmed in HCV-infected cells. The association of lipid rafts with autophagosomes was specific to HCV, as it was not detected in autophagosomes induced by nutrient starvation. Further analysis indicated that the autophagosomes purified from HCV replicon cells could mediate HCV RNA replication in a lipid raft-dependent manner, as the depletion of cholesterol, a major component of lipid rafts, from autophagosomes abolished HCV RNA replication. Our studies thus demonstrated that HCV could specifically induce the association of lipid rafts with autophagosomes for its RNA replication. IMPORTANCE HCV can cause severe liver diseases, including cirrhosis and hepatocellular carcinoma, and is one of the most important human pathogens. Infection with HCV can lead to the reorganization of membrane structures in its host cells, including the induction of autophagosomes. In this study, we developed a procedure to purify HCV-induced autophagosomes and demonstrated that HCV could induce the localization of lipid rafts to autophagosomes to mediate its RNA replication. This finding provided important information for further understanding the life cycle of HCV and its interaction with the host cells. PMID:28747506

Cinnamic acid derivatives inhibit hepatitis C virus replication via the induction of oxidative stress.

PubMed

Amano, Ryota; Yamashita, Atsuya; Kasai, Hirotake; Hori, Tomoka; Miyasato, Sayoko; Saito, Setsu; Yokoe, Hiromasa; Takahashi, Kazunori; Tanaka, Tomohisa; Otoguro, Teruhime; Maekawa, Shinya; Enomoto, Nobuyuki; Tsubuki, Masayoshi; Moriishi, Kohji

2017-09-01

Several cinnamic acid derivatives have been reported to exhibit antiviral activity. In this study, we prepared 17 synthetic cinnamic acid derivatives and screened them to identify an effective antiviral compound against hepatitis C virus (HCV). Compound 6, one of two hit compounds, suppressed the viral replications of genotypes 1b, 2a, 3a, and 4a with EC 50 values of 1.5-8.1 μM and SI values of 16.2-94.2. The effect of compound 6 on the phosphorylation of Tyr 705 in signal transducer and activator of transcription 3 (STAT3) was investigated because a cinnamic acid derivative AG490 was reported to suppress HCV replication and the activity of Janus kinase (JAK) 2. Compound 6 potently suppressed HCV replication, but it did not inhibit the JAK1/2-dependent phosphorylation of STAT3 Tyr 705  at the same concentration. Furthermore, a pan-JAK inhibitor tofacitinib potently impaired phosphorylation of STAT3 Tyr 705 , but it did not inhibit HCV replication in the replicon cells and HCV-infected cells at the same concentration, supporting the notion that the phosphorylated state of STAT3 Tyr 705 is not necessarily correlated with HCV replication. The production of reactive oxygen species (ROS) was induced by treatment with compound 6, whereas N-acetyl-cysteine restored HCV replication and impaired ROS production in the replicon cells treated with compound 6. These data suggest that compound 6 inhibits HCV replication via the induction of oxidative stress. Copyright © 2017 Elsevier B.V. All rights reserved.

Low Oxygen Tension Enhances Hepatitis C Virus Replication

PubMed Central

Kalliampakou, K. I.; Kotta-Loizou, I.; Befani, C.; Liakos, P.; Simos, G.; Mentis, A. F.; Kalliaropoulos, A.; Doumba, P. P.; Smirlis, D.; Foka, P.; Bauhofer, O.; Poenisch, M.; Windisch, M. P.; Lee, M. E.; Koskinas, J.; Bartenschlager, R.

2013-01-01

Low oxygen tension exerts a significant effect on the replication of several DNA and RNA viruses in cultured cells. In vitro propagation of hepatitis C virus (HCV) has thus far been studied under atmospheric oxygen levels despite the fact that the liver tissue microenvironment is hypoxic. In this study, we investigated the efficiency of HCV production in actively dividing or differentiating human hepatoma cells cultured under low or atmospheric oxygen tensions. By using both HCV replicons and infection-based assays, low oxygen was found to enhance HCV RNA replication whereas virus entry and RNA translation were not affected. Hypoxia signaling pathway-focused DNA microarray and real-time quantitative reverse transcription-PCR (qRT-PCR) analyses revealed an upregulation of genes related to hypoxic stress, glycolytic metabolism, cell growth, and proliferation when cells were kept under low (3% [vol/vol]) oxygen tension, likely reflecting cell adaptation to anaerobic conditions. Interestingly, hypoxia-mediated enhancement of HCV replication correlated directly with the increase in anaerobic glycolysis and creatine kinase B (CKB) activity that leads to elevated ATP production. Surprisingly, activation of hypoxia-inducible factor alpha (HIF-α) was not involved in the elevation of HCV replication. Instead, a number of oncogenes known to be associated with glycolysis were upregulated and evidence that these oncogenes contribute to hypoxia-mediated enhancement of HCV replication was obtained. Finally, in liver biopsy specimens of HCV-infected patients, the levels of hypoxia and anaerobic metabolism markers correlated with HCV RNA levels. These results provide new insights into the impact of oxygen tension on the intricate HCV-host cell interaction. PMID:23269812

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosley, Ralph T.; Edwards, Thomas E.; Murakami, Eisuke

The replication of the hepatitis C viral (HCV) genome is accomplished by the NS5B RNA-dependent RNA polymerase (RdRp), for which mechanistic understanding and structure-guided drug design efforts have been hampered by its propensity to crystallize in a closed, polymerization-incompetent state. The removal of an autoinhibitory {beta}-hairpin loop from genotype 2a HCV NS5B increases de novo RNA synthesis by >100-fold, promotes RNA binding, and facilitated the determination of the first crystallographic structures of HCV polymerase in complex with RNA primer-template pairs. These crystal structures demonstrate the structural realignment required for primer-template recognition and elongation, provide new insights into HCV RNA synthesismore » at the molecular level, and may prove useful in the structure-based design of novel antiviral compounds. Additionally, our approach for obtaining the RNA primer-template-bound structure of HCV polymerase may be generally applicable to solving RNA-bound complexes for other viral RdRps that contain similar regulatory {beta}-hairpin loops, including bovine viral diarrhea virus, dengue virus, and West Nile virus.« less

The New Era of Interferon-Free Treatment of Chronic Hepatitis C

PubMed Central

Solbach, Philipp; Wedemeyer, Heiner

2015-01-01

Summary Background Within the development and approval of several new direct-acting antivirals (DAA) against hepatitis C virus (HCV), a new era of hepatitis C therapy has begun. Even more treatment options are likely to become available during the next 1-2 years. Methods A summary of the current phase II and III trials investigating DAA and a review of the recent HCV guidelines was conducted. Results With the development of new potent DAA and the approval of different DAA combinations, cure rates of HCV infection of >90% are achievable for almost all HCV genotypes and stages of liver disease. Currently available DAA target different steps in the HCV replication cycle, in particular the NS3/4A protease, the NS5B polymerase, and the NS5A replication complex. Treatment duration varies between 8 and 24 weeks depending on the stage of fibrosis, prior treatment, HCV viral load, and HCV genotype. Ribavirin is required only for some treatment regimens and may be particularly beneficial in patients with cirrhosis. DAA resistance influences treatment outcome only marginally; thus, drug resistance testing is not routinely recommended before treatment. In the case of treatment failure, however, resistance testing should be performed before re-treatment with other DAA is initiated. Conclusion With the new, almost side effect-free DAA treatment options chronic HCV infection became a curable disease. The clinical benefit of DAA combination therapies in patients with advanced cirrhosis and the effects on incidence rates of hepatocellular carcinoma remain to be determined. PMID:26557839

Visualization and Measurement of ATP Levels in Living Cells Replicating Hepatitis C Virus Genome RNA

PubMed Central

Ando, Tomomi; Imamura, Hiromi; Suzuki, Ryosuke; Aizaki, Hideki; Watanabe, Toshiki; Wakita, Takaji; Suzuki, Tetsuro

2012-01-01

Adenosine 5′-triphosphate (ATP) is the primary energy currency of all living organisms and participates in a variety of cellular processes. Although ATP requirements during viral lifecycles have been examined in a number of studies, a method by which ATP production can be monitored in real-time, and by which ATP can be quantified in individual cells and subcellular compartments, is lacking, thereby hindering studies aimed at elucidating the precise mechanisms by which viral replication energized by ATP is controlled. In this study, we investigated the fluctuation and distribution of ATP in cells during RNA replication of the hepatitis C virus (HCV), a member of the Flaviviridae family. We demonstrated that cells involved in viral RNA replication actively consumed ATP, thereby reducing cytoplasmic ATP levels. Subsequently, a method to measure ATP levels at putative subcellular sites of HCV RNA replication in living cells was developed by introducing a recently-established Förster resonance energy transfer (FRET)-based ATP indicator, called ATeam, into the NS5A coding region of the HCV replicon. Using this method, we were able to observe the formation of ATP-enriched dot-like structures, which co-localize with non-structural viral proteins, within the cytoplasm of HCV-replicating cells but not in non-replicating cells. The obtained FRET signals allowed us to estimate ATP concentrations within HCV replicating cells as ∼5 mM at possible replicating sites and ∼1 mM at peripheral sites that did not appear to be involved in HCV replication. In contrast, cytoplasmic ATP levels in non-replicating Huh-7 cells were estimated as ∼2 mM. To our knowledge, this is the first study to demonstrate changes in ATP concentration within cells during replication of the HCV genome and increased ATP levels at distinct sites within replicating cells. ATeam may be a powerful tool for the study of energy metabolism during replication of the viral genome. PMID:22396648

Novel perspectives for hepatitis A virus therapy revealed by comparative analysis of hepatitis C virus and hepatitis A virus RNA replication.

PubMed

Esser-Nobis, Katharina; Harak, Christian; Schult, Philipp; Kusov, Yuri; Lohmann, Volker

2015-08-01

Hepatitis A virus (HAV) and hepatitis C virus (HCV) are two positive-strand RNA viruses sharing a similar biology, but causing opposing infection outcomes, with HAV always being cleared and HCV establishing persistence in the majority of infections. To gain deeper insight into determinants of replication, persistence, and treatment, we established a homogenous cell-culture model allowing a thorough comparison of RNA replication of both viruses. By screening different human liver-derived cell lines with subgenomic reporter replicons of HAV as well as of different HCV genotypes, we found that Huh7-Lunet cells supported HAV- and HCV-RNA replication with similar efficiency and limited interference between both replicases. HAV and HCV replicons were similarly sensitive to interferon (IFN), but differed in their ability to establish persistent replication in cell culture. In contrast to HCV, HAV replicated independently from microRNA-122 and phosphatidylinositol 4-kinase IIIα and β (PI4KIII). Both viruses were efficiently inhibited by cyclosporin A and NIM811, a nonimmunosuppressive analog thereof, suggesting an overlapping dependency on cyclophilins for replication. However, analysis of a broader set of inhibitors revealed that, in contrast to HCV, HAV does not depend on cyclophilin A, but rather on adenosine-triphosphate-binding cassette transporters and FK506-binding proteins. Finally, silibinin, but not its modified intravenous formulation, efficiently inhibited HAV genome replication in vitro, suggesting oral silibinin as a potential therapeutic option for HAV infections. We established a cell-culture model enabling comparative studies on RNA replication of HAV and HCV in a homogenous cellular background with comparable replication efficiency. We thereby identified new host cell targets and potential treatment options for HAV and set the ground for future studies to unravel determinants of clearance and persistence. © 2015 by the American Association for the Study of Liver Diseases.

Diverse Effects of Cyclosporine on Hepatitis C Virus Strain Replication

PubMed Central

Ishii, Naoto; Watashi, Koichi; Hishiki, Takayuki; Goto, Kaku; Inoue, Daisuke; Hijikata, Makoto; Wakita, Takaji; Kato, Nobuyuki; Shimotohno, Kunitada

2006-01-01

Recently, a production system for infectious particles of hepatitis C virus (HCV) utilizing the genotype 2a JFH1 strain has been developed. This strain has a high capacity for replication in the cells. Cyclosporine (CsA) has a suppressive effect on HCV replication. In this report, we characterize the anti-HCV effect of CsA. We observe that the presence of viral structural proteins does not influence the anti-HCV activity of CsA. Among HCV strains, the replication of genotype 1b replicons was strongly suppressed by treatment with CsA. In contrast, JFH1 replication was less sensitive to CsA and its analog, NIM811. Replication of JFH1 did not require the cellular replication cofactor, cyclophilin B (CyPB). CyPB stimulated the RNA binding activity of NS5B in the genotype 1b replicon but not the genotype 2a JFH1 strain. These findings provide an insight into the mechanisms of diversity governing virus-cell interactions and in the sensitivity of these strains to antiviral agents. PMID:16611911

Dynamic Interaction of Stress Granules, DDX3X, and IKK-α Mediates Multiple Functions in Hepatitis C Virus Infection

PubMed Central

Pène, Véronique; Sodroski, Catherine; Hsu, Ching-Sheng

2015-01-01

ABSTRACT The ubiquitous ATP-dependent RNA helicase DDX3X is involved in many cellular functions, including innate immunity, and is a pivotal host factor for hepatitis C virus (HCV) infection. Recently, we showed that DDX3X specifically recognizes the HCV 3′ untranslated region (UTR), leading to the activation of IKK-α and a cascade of lipogenic signaling to facilitate lipid droplet biogenesis and viral assembly (Q. Li, V. Pene, S. Krishnamurthy, H. Cha, and T. J. Liang, Nat Med 19:722–729, 2013, http://dx.doi.org/10.1038/nm.3190). The interaction of DDX3X with HCV core protein seems to be dispensable for its proviral role. In this study, through systematic imaging and biochemical and virologic approaches, we identified a dynamic association between DDX3X and various cellular compartments and viral elements mediating multiple functions of DDX3X in productive HCV infection. Upon HCV infection, the HCV 3′UTR interacts with DDX3X and IKK-α, which redistribute to speckle-like cytoplasmic structures shown to be stress granules (SGs). As viral proteins accumulate in infected cells, DDX3X granules together with SG-associated proteins redistribute and colocalize with HCV core protein around lipid droplets (LDs). IKK-α, however, does not relocate to the LD but translocates to the nucleus. In HCV-infected cells, various HCV nonstructural proteins also interact or colocalize with DDX3X in close proximity to SGs and LDs, consistent with the tight juxtaposition of the replication complex and the assembly site at the surface of LDs. Short interfering RNA (siRNA)-mediated silencing of DDX3X and multiple SG components markedly inhibits HCV infection. Our data suggest that DDX3X initiates a multifaceted cellular program involving dynamic associations with HCV RNA and proteins, IKK-α, SG, and LD surfaces for its crucial role in the HCV life cycle. IMPORTANCE DDX3X is a proviral host factor for HCV infection. Recently, we showed that DDX3X binds to the HCV 3′UTR, activating IKK-α and cellular lipogenesis to facilitate viral assembly (Q. Li et al., Nat Med 19:722–729, 2013, http://dx.doi.org/10.1038/nm.3190). Here, we report associations of DDX3X with various cellular compartments and viral elements that mediate its multiple functions in the HCV life cycle. Upon infection, the HCV 3′UTR redistributes DDX3X and IKK-α to speckle-like cytoplasmic structures shown to be SGs. Subsequently, interactions between DDX3X, SG, and HCV proteins facilitate the translocation of DDX3X-SG complexes to the LD surface. HCV nonstructural proteins are shown to colocalize with DDX3X in close proximity to SGs and LDs, consistent with the tight juxtaposition of the HCV replication complex and assembly site at the LD surface. Our data demonstrate that DDX3X initiates a multifaceted cellular program involving dynamic associations with HCV elements, IKK-α, SGs, and LDs for its critical role in HCV infection. PMID:25740981

Dynamic Interaction of Stress Granules, DDX3X, and IKK-α Mediates Multiple Functions in Hepatitis C Virus Infection.

PubMed

Pène, Véronique; Li, Qisheng; Sodroski, Catherine; Hsu, Ching-Sheng; Liang, T Jake

2015-05-01

The ubiquitous ATP-dependent RNA helicase DDX3X is involved in many cellular functions, including innate immunity, and is a pivotal host factor for hepatitis C virus (HCV) infection. Recently, we showed that DDX3X specifically recognizes the HCV 3' untranslated region (UTR), leading to the activation of IKK-α and a cascade of lipogenic signaling to facilitate lipid droplet biogenesis and viral assembly (Q. Li, V. Pene, S. Krishnamurthy, H. Cha, and T. J. Liang, Nat Med 19:722-729, 2013, http://dx.doi.org/10.1038/nm.3190). The interaction of DDX3X with HCV core protein seems to be dispensable for its proviral role. In this study, through systematic imaging and biochemical and virologic approaches, we identified a dynamic association between DDX3X and various cellular compartments and viral elements mediating multiple functions of DDX3X in productive HCV infection. Upon HCV infection, the HCV 3'UTR interacts with DDX3X and IKK-α, which redistribute to speckle-like cytoplasmic structures shown to be stress granules (SGs). As viral proteins accumulate in infected cells, DDX3X granules together with SG-associated proteins redistribute and colocalize with HCV core protein around lipid droplets (LDs). IKK-α, however, does not relocate to the LD but translocates to the nucleus. In HCV-infected cells, various HCV nonstructural proteins also interact or colocalize with DDX3X in close proximity to SGs and LDs, consistent with the tight juxtaposition of the replication complex and the assembly site at the surface of LDs. Short interfering RNA (siRNA)-mediated silencing of DDX3X and multiple SG components markedly inhibits HCV infection. Our data suggest that DDX3X initiates a multifaceted cellular program involving dynamic associations with HCV RNA and proteins, IKK-α, SG, and LD surfaces for its crucial role in the HCV life cycle. IMPORTANCE DDX3X is a proviral host factor for HCV infection. Recently, we showed that DDX3X binds to the HCV 3'UTR, activating IKK-α and cellular lipogenesis to facilitate viral assembly (Q. Li et al., Nat Med 19:722-729, 2013, http://dx.doi.org/10.1038/nm.3190). Here, we report associations of DDX3X with various cellular compartments and viral elements that mediate its multiple functions in the HCV life cycle. Upon infection, the HCV 3'UTR redistributes DDX3X and IKK-α to speckle-like cytoplasmic structures shown to be SGs. Subsequently, interactions between DDX3X, SG, and HCV proteins facilitate the translocation of DDX3X-SG complexes to the LD surface. HCV nonstructural proteins are shown to colocalize with DDX3X in close proximity to SGs and LDs, consistent with the tight juxtaposition of the HCV replication complex and assembly site at the LD surface. Our data demonstrate that DDX3X initiates a multifaceted cellular program involving dynamic associations with HCV elements, IKK-α, SGs, and LDs for its critical role in HCV infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Cyclophilin B is a functional regulator of hepatitis C virus RNA polymerase.

PubMed

Watashi, Koichi; Ishii, Naoto; Hijikata, Makoto; Inoue, Daisuke; Murata, Takayuki; Miyanari, Yusuke; Shimotohno, Kunitada

2005-07-01

Viruses depend on host-derived factors for their efficient genome replication. Here, we demonstrate that a cellular peptidyl-prolyl cis-trans isomerase (PPIase), cyclophilin B (CyPB), is critical for the efficient replication of the hepatitis C virus (HCV) genome. CyPB interacted with the HCV RNA polymerase NS5B to directly stimulate its RNA binding activity. Both the RNA interference (RNAi)-mediated reduction of endogenous CyPB expression and the induced loss of NS5B binding to CyPB decreased the levels of HCV replication. Thus, CyPB functions as a stimulatory regulator of NS5B in HCV replication machinery. This regulation mechanism for viral replication identifies CyPB as a target for antiviral therapeutic strategies.

Direct imaging of the disruption of hepatitis C virus replication complexes by inhibitors of lipid metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyn, Rodney K.; Department of Chemistry, University of Ottawa, 10 Marie-Curie, Ottawa, K1N 6N5; Kennedy, David C.

2009-11-10

Here we have simultaneously characterized the influence of inhibitors of peroxisome proliferator-activated receptor alpha (PPARalpha) and the mevalonate pathway on hepatocyte lipid metabolism and the subcellular localization of hepatitis C virus (HCV) RNA using two-photon fluorescence (TPF) and coherent anti-Stokes Raman scattering (CARS) microscopy. Using this approach, we demonstrate that modulators of PPARalpha signaling rapidly cause the dispersion of HCV RNA from replication sites and simultaneously induce lipid storage and increases in lipid droplet size. We demonstrate that reductions in the levels of cholesterol resulting from inhibition of the mevalonate pathway upregulates triglyceride levels. We also show that the ratemore » of dispersion of HCV RNA is very rapid when using a PPARalpha antagonist. This occurs with a faster rate to that of direct inhibition of 3-hydroxy-3-methyglutaryl CoA reductase (HMG-CoA reductase) using lovastatin in living cells, demonstrating the potential therapeutic value of modulating host cell pathways as part of a strategy to eliminate chronic HCV infection.« less

Preclinical Profile and Characterization of the Hepatitis C Virus NS3 Protease Inhibitor Asunaprevir (BMS-650032)

PubMed Central

Sheaffer, Amy K.; Friborg, Jacques; Hernandez, Dennis; Falk, Paul; Zhai, Guangzhi; Levine, Steven; Chaniewski, Susan; Yu, Fei; Barry, Diana; Chen, Chaoqun; Lee, Min S.; Mosure, Kathy; Sun, Li-Qiang; Sinz, Michael; Meanwell, Nicholas A.; Colonno, Richard J.; Knipe, Jay; Scola, Paul

2012-01-01

Asunaprevir (ASV; BMS-650032) is a hepatitis C virus (HCV) NS3 protease inhibitor that has demonstrated efficacy in patients chronically infected with HCV genotype 1 when combined with alfa interferon and/or the NS5A replication complex inhibitor daclatasvir. ASV competitively binds to the NS3/4A protease complex, with Ki values of 0.4 and 0.24 nM against recombinant enzymes representing genotypes 1a (H77) and 1b (J4L6S), respectively. Selectivity was demonstrated by the absence of any significant activity against the closely related GB virus-B NS3 protease and a panel of human serine or cysteine proteases. In cell culture, ASV inhibited replication of HCV replicons representing genotypes 1 and 4, with 50% effective concentrations (EC50s) ranging from 1 to 4 nM, and had weaker activity against genotypes 2 and 3 (EC50, 67 to 1,162 nM). Selectivity was again demonstrated by the absence of activity (EC50, >12 μM) against a panel of other RNA viruses. ASV exhibited additive or synergistic activity in combination studies with alfa interferon, ribavirin, and/or inhibitors specifically targeting NS5A or NS5B. Plasma and tissue exposures in vivo in several animal species indicated that ASV displayed a hepatotropic disposition (liver-to-plasma ratios ranging from 40- to 359-fold across species). Twenty-four hours postdose, liver exposures across all species tested were ≥110-fold above the inhibitor EC50s observed with HCV genotype-1 replicons. Based on these virologic and exposure properties, ASV holds promise for future utility in a combination with other anti-HCV agents in the treatment of HCV-infected patients. PMID:22869577

Hepatitis C Virus Infection Induces Autophagy as a Prosurvival Mechanism to Alleviate Hepatic ER-Stress Response

PubMed Central

Dash, Srikanta; Chava, Srinivas; Aydin, Yucel; Chandra, Partha K.; Ferraris, Pauline; Chen, Weina; Balart, Luis A.; Wu, Tong; Garry, Robert F.

2016-01-01

Hepatitis C virus (HCV) infection frequently leads to chronic liver disease, liver cirrhosis and hepatocellular carcinoma (HCC). The molecular mechanisms by which HCV infection leads to chronic liver disease and HCC are not well understood. The infection cycle of HCV is initiated by the attachment and entry of virus particles into a hepatocyte. Replication of the HCV genome inside hepatocytes leads to accumulation of large amounts of viral proteins and RNA replication intermediates in the endoplasmic reticulum (ER), resulting in production of thousands of new virus particles. HCV-infected hepatocytes mount a substantial stress response. How the infected hepatocyte integrates the viral-induced stress response with chronic infection is unknown. The unfolded protein response (UPR), an ER-associated cellular transcriptional response, is activated in HCV infected hepatocytes. Over the past several years, research performed by a number of laboratories, including ours, has shown that HCV induced UPR robustly activates autophagy to sustain viral replication in the infected hepatocyte. Induction of the cellular autophagy response is required to improve survival of infected cells by inhibition of cellular apoptosis. The autophagy response also inhibits the cellular innate antiviral program that usually inhibits HCV replication. In this review, we discuss the physiological implications of the HCV-induced chronic ER-stress response in the liver disease progression. PMID:27223299

Aeginetia indica Decoction Inhibits Hepatitis C Virus Life Cycle

PubMed Central

Lin, Cheng-Wei; Lo, Chieh-Wen; Tsai, Chia-Ni; Pan, Ting-Chun; Chen, Pin-Yin

2018-01-01

Chronic hepatitis C virus (HCV) infection is still a global epidemic despite the introduction of several highly effective direct-acting antivirals that are tagged with sky-high prices. The present study aimed to identify an herbal decoction that ameliorates HCV infection. Among six herbal decoctions tested, the Aeginetia indica decoction had the most profound effect on the HCV reporter activity in infected Huh7.5.1 liver cells in a dose- and time-dependent manner. The Aeginetia indica decoction exerted multiple inhibitory effects on the HCV life cycle. Pretreatment of the cells with the Aeginetia indica decoction prior to HCV infection reduced the HCV RNA and non-structural protein 3 (NS3) protein levels in the infected cells. The Aeginetia indica decoction reduced HCV internal ribosome entry site-mediated protein translation activity. It also reduced the HCV RNA level in the infected cells in association with reduced NS5A phosphorylation at serine 235, a predominant phosphorylation event indispensable to HCV replication. Thus, the Aeginetia indica decoction inhibits HCV infection, translation, and replication. Mechanistically, the Aeginetia indica decoction probably reduced HCV replication via reducing NS5A phosphorylation at serine 235. PMID:29315273

3D cultured immortalized human hepatocytes useful to develop drugs for blood-borne HCV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aly, Hussein Hassan; Shimotohno, Kunitada; Hijikata, Makoto

2009-02-06

Due to the high polymorphism of natural hepatitis C virus (HCV) variants, existing recombinant HCV replication models have failed to be effective in developing effective anti-HCV agents. In the current study, we describe an in vitro system that supports the infection and replication of natural HCV from patient blood using an immortalized primary human hepatocyte cell line cultured in a three-dimensional (3D) culture system. Comparison of the gene expression profile of cells cultured in the 3D system to those cultured in the existing 2D system demonstrated an up-regulation of several genes activated by peroxisome proliferator-activated receptor alpha (PPAR{alpha}) signaling. Furthermore,more » using PPAR{alpha} agonists and antagonists, we also analyzed the effect of PPAR{alpha} signaling on the modulation of HCV replication using this system. The 3D in vitro system described in this study provides significant insight into the search for novel anti-HCV strategies that are specific to various strains of HCV.« less

3D Spatially Resolved Models of the Intracellular Dynamics of the Hepatitis C Genome Replication Cycle

PubMed Central

Reiter, Sebastian; Grillo, Alfio; Herrmann, Eva; Wittum, Gabriel

2017-01-01

Mathematical models of virus dynamics have not previously acknowledged spatial resolution at the intracellular level despite substantial arguments that favor the consideration of intracellular spatial dependence. The replication of the hepatitis C virus (HCV) viral RNA (vRNA) occurs within special replication complexes formed from membranes derived from endoplasmatic reticulum (ER). These regions, termed membranous webs, are generated primarily through specific interactions between nonstructural virus-encoded proteins (NSPs) and host cellular factors. The NSPs are responsible for the replication of the vRNA and their movement is restricted to the ER surface. Therefore, in this study we developed fully spatio-temporal resolved models of the vRNA replication cycle of HCV. Our simulations are performed upon realistic reconstructed cell structures—namely the ER surface and the membranous webs—based on data derived from immunostained cells replicating HCV vRNA. We visualized 3D simulations that reproduced dynamics resulting from interplay of the different components of our models (vRNA, NSPs, and a host factor), and we present an evaluation of the concentrations for the components within different regions of the cell. Thus far, our model is restricted to an internal portion of a hepatocyte and is qualitative more than quantitative. For a quantitative adaption to complete cells, various additional parameters will have to be determined through further in vitro cell biology experiments, which can be stimulated by the results described in the present study. PMID:28973992

Altered expression and activation of signal transducers and activators of transcription (STATs) in hepatitis C virus infection: in vivo and in vitro studies.

PubMed

Larrea, E; Aldabe, R; Molano, E; Fernandez-Rodriguez, C M; Ametzazurra, A; Civeira, M P; Prieto, J

2006-08-01

Signal transducers and activators of transcription (STATs) play a critical role in antiviral defence. STAT3 is also important in cell protection against inflammatory damage. STAT proteins are activated by interferons and by hepatoprotective cytokines of the interleukin 6 superfamily, including cardiotrophin 1. We analysed the status of STATs in hepatitis C virus (HCV) infected livers and the relationship between expression and activation of STATs and HCV replication in Huh7 cells transfected with HCV genomic replicon. STAT3alpha expression was reduced in HCV infected livers showing an inverse correlation with serum alanine aminotransferase. In patients with HCV infection, nuclear staining for phosphorylated STAT3 was faint in parenchymal cells (although conspicuous in infiltrating leucocytes), in contrast with strong nuclear staining in hepatocytes from control livers. Expression and activation of STAT1 (a factor activated by both interferon (IFN)-alpha and IFN-gamma) were increased in HCV infected livers, particularly in those with high inflammatory activity. Conversely, phosphorylated STAT2 (a factor selectively activated by IFN-alpha) was undetectable in livers with HCV infection, a finding that was associated with marked downregulation of the two functional subunits of the IFN-alpha receptor. HCV replication in Huh7 cells caused STAT3alpha downregulation and blocked STAT3 phosphorylation by either IFN-alpha or cardiotrophin 1. HCV replication in Huh7 cells also inhibited STAT1 and STAT2 activation by IFN-alpha while there was no impairment of STAT1 phosphorylation by the proinflammatory cytokine IFN-gamma. STAT3 is downregulated in HCV infected livers and in Huh7 cells bearing the full length HCV replicon. HCV replication is associated with impaired Jak-STAT signalling by antiviral and cytoprotective cytokines. These effects may favour viral replication while facilitating the progression of liver disease.

Interference of hepatitis C virus RNA replication by short interfering RNAs

NASA Astrophysics Data System (ADS)

Kapadia, Sharookh B.; Brideau-Andersen, Amy; Chisari, Francis V.

2003-02-01

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, which can lead to the development of liver cirrhosis and hepatocellular carcinoma. Current therapy of patients with chronic HCV infection includes treatment with IFN in combination with ribavirin. Because most treated patients do not resolve the infection, alternative treatment is essential. RNA interference (RNAi) is a recently discovered antiviral mechanism present in plants and animals that induces double-stranded RNA degradation. Using a selectable subgenomic HCV replicon cell culture system, we have shown that RNAi can specifically inhibit HCV RNA replication and protein expression in Huh-7 cells that stably replicate the HCV genome, and that this antiviral effect is independent of IFN. These results suggest that RNAi may represent a new approach for the treatment of persistent HCV infection.

Hepatitis C Virus Induces the Mitochondrial Translocation of Parkin and Subsequent Mitophagy

PubMed Central

Kim, Seong-Jun; Syed, Gulam H.; Siddiqui, Aleem

2013-01-01

Hepatitis C Virus (HCV) induces intracellular events that trigger mitochondrial dysfunction and promote host metabolic alterations. Here, we investigated selective autophagic degradation of mitochondria (mitophagy) in HCV-infected cells. HCV infection stimulated Parkin and PINK1 gene expression, induced perinuclear clustering of mitochondria, and promoted mitochondrial translocation of Parkin, an initial event in mitophagy. Liver tissues from chronic HCV patients also exhibited notable levels of Parkin induction. Using multiple strategies involving confocal and electron microscopy, we demonstrated that HCV-infected cells display greater number of mitophagosomes and mitophagolysosomes compared to uninfected cells. HCV-induced mitophagy was evidenced by the colocalization of LC3 puncta with Parkin-associated mitochondria and lysosomes. Ultrastructural analysis by electron microscopy and immunoelectron microscopy also displayed engulfment of damaged mitochondria in double membrane vesicles in HCV-infected cells. The HCV-induced mitophagy occurred irrespective of genotypic differences. Silencing Parkin and PINK1 hindered HCV replication suggesting the functional relevance of mitophagy in HCV propagation. HCV-mediated decline of mitochondrial complex I enzyme activity was rescued by chemical inhibition of mitophagy or by Parkin silencing. Overall our results suggest that HCV induces Parkin-dependent mitophagy, which may have significant contribution in mitochondrial liver injury associated with chronic hepatitis C. PMID:23555273

Pegylated IFN-α suppresses hepatitis C virus by promoting the DAPK-mTOR pathway.

PubMed

Liu, Wei-Liang; Yang, Hung-Chih; Hsu, Ching-Sheng; Wang, Chih-Chiang; Wang, Tzu-San; Kao, Jia-Horng; Chen, Ding-Shinn

2016-12-20

Death-associated protein kinase (DAPK) has been found to be induced by IFN, but its antiviral activity remains elusive. Therefore, we investigated whether DAPK plays a role in the pegylated IFN-α (peg-IFN-α)-induced antiviral activity against hepatitis C virus (HCV) replication. Primary human hepatocytes, Huh-7, and infectious HCV cell culture were used to study the relationship between peg-IFN-α and the DAPK-mammalian target of rapamycin (mTOR) pathways. The activation of DAPK and signaling pathways were determined using immunoblotting. By silencing DAPK and mTOR, we further assessed the role of DAPK and mTOR in the peg-IFN-α-induced suppression of HCV replication. Peg-IFN-α up-regulated the expression of DAPK and mTOR, which was associated with the suppression of HCV replication. Overexpression of DAPK enhanced mTOR expression and then inhibited HCV replication. In addition, knockdown of DAPK reduced the expression of mTOR in peg-IFN-α-treated cells, whereas silencing of mTOR had no effect on DAPK expression, suggesting mTOR may be a downstream effector of DAPK. More importantly, knockdown of DAPK or mTOR significantly mitigated the inhibitory effects of peg-IFN-α on HCV replication. In conclusion, our data suggest that the DAPK-mTOR pathway is critical for anti-HCV effects of peg-IFN-α.

NS3 from Hepatitis C Virus Strain JFH-1 Is an Unusually Robust Helicase That Is Primed To Bind and Unwind Viral RNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Ting; Ren, Xiaoming; Adams, Rebecca L.

Hepatitis C viruses (HCV) encode a helicase enzyme that is essential for viral replication and assembly (nonstructural protein 3 [NS3]). This helicase has become the focus of extensive basic research on the general helicase mechanism, and it is also of interest as a novel drug target. Despite the importance of this protein, mechanistic work on NS3 has been conducted almost exclusively on variants from HCV genotype 1. Our understanding of NS3 from the highly active HCV strains that are used to study HCV genetics and mechanism in cell culture (such as JFH-1) is lacking. We therefore set out to determinemore » whether NS3 from the replicatively efficient genotype 2a strain JFH-1 displays novel functional or structural properties. Using biochemical assays for RNA binding and duplex unwinding, we show that JFH-1 NS3 binds RNA much more rapidly than the previously studied NS3 variants from genotype 1b. Unlike NS3 variants from other genotypes, JFH-1 NS3 binds RNA with high affinity in a functionally active form that is capable of immediately unwinding RNA duplexes without undergoing rate-limiting conformational changes that precede activation. Unlike other superfamily 2 (SF2) helicases, JFH-1 NS3 does not require long 3' overhangs, and it unwinds duplexes that are flanked by only a few nucleotides, as in the folded HCV genome. To understand the physical basis for this, we solved the crystal structure of JFH-1 NS3, revealing a novel conformation that contains an open, positively charged RNA binding cleft that is primed for productive interaction with RNA targets, potentially explaining robust replication by HCV JFH-1. IMPORTANCEGenotypes of HCV are as divergent as different types of flavivirus, and yet mechanistic features of HCV variants are presumed to be held in common. One of the most well-studied components of the HCV replication complex is a helicase known as nonstructural protein 3 (NS3). We set out to determine whether this important mechanical component possesses biochemical and structural properties that differ between common strains such as those of genotype 1b and a strain of HCV that replicates with exceptional efficiency (JFH-1, classified as genotype 2a). Indeed, unlike the inefficient genotype 1b NS3, which has been well studied, JFH-1 NS3 is a superhelicase with strong RNA affinity and high unwinding efficiency on a broad range of targets. Crystallographic analysis reveals architectural features that promote enhanced biochemical activity of JFH-1 NS3. These findings show that even within a single family of viruses, drift in sequence can result in the acquisition of radically new functional properties that enhance viral fitness.« less

A New Age-Structured Multiscale Model of the Hepatitis C Virus Life-Cycle During Infection and Therapy With Direct-Acting Antiviral Agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quintela, Barbara de M.; Conway, Jessica M.; Hyman, James M.

Here, the dynamics of hepatitis C virus (HCV) RNA during translation and replication within infected cells were added to a previous age-structured multiscale mathematical model of HCV infection and treatment. The model allows the study of the dynamics of HCV RNA inside infected cells as well as the release of virus from infected cells and the dynamics of subsequent new cell infections. The model was used to fit in vitro data and estimate parameters characterizing HCV replication. This is the first model to our knowledge to consider both positive and negative strands of HCV RNA with an age-structured multiscale modelingmore » approach. Using this model we also studied the effects of direct-acting antiviral agents (DAAs) in blocking HCV RNA intracellular replication and the release of new virions and fit the model to in vivo data obtained from HCV-infected subjects under therapy.« less

A New Age-Structured Multiscale Model of the Hepatitis C Virus Life-Cycle During Infection and Therapy With Direct-Acting Antiviral Agents

DOE PAGES

Quintela, Barbara de M.; Conway, Jessica M.; Hyman, James M.; ...

2018-04-04

Here, the dynamics of hepatitis C virus (HCV) RNA during translation and replication within infected cells were added to a previous age-structured multiscale mathematical model of HCV infection and treatment. The model allows the study of the dynamics of HCV RNA inside infected cells as well as the release of virus from infected cells and the dynamics of subsequent new cell infections. The model was used to fit in vitro data and estimate parameters characterizing HCV replication. This is the first model to our knowledge to consider both positive and negative strands of HCV RNA with an age-structured multiscale modelingmore » approach. Using this model we also studied the effects of direct-acting antiviral agents (DAAs) in blocking HCV RNA intracellular replication and the release of new virions and fit the model to in vivo data obtained from HCV-infected subjects under therapy.« less

Zinc Mesoporphyrin Induces Rapid Proteasomal Degradation of Hepatitis C Nonstructural 5A Protein in Human Hepatoma Cells

PubMed Central

Hou, Weihong; Tian, Qing; Zheng, Jianyu; Bonkovsky, Herbert L.

2009-01-01

Background & Aims The nonstructural 5A (NS5A) protein of hepatitis C virus (HCV), plays a critical role in HCV replication and is an attractive target for the therapy of HCV infection. So far, little is known about the post-translational regulation of NS5A protein and its precise role in HCV RNA replication. Our objectives were to elucidate the down-regulation of NS5A protein and HCV RNA replication by zinc mesoporphyrin (ZnMP), and the mechanism by which this process occurs. Methods Human hepatoma cells expressing HCV proteins were used to investigate the post-translational regulation of ZnMP on NS5A protein by Western blots (WB) and immunoprecipitation (IP). Quantitative RT-PCR (qRT-PCR) was used to determine the effects of ZnMP on HCV RNA replication. Results ZnMP selectively and markedly down-regulated NS5A protein levels by increasing degradation of NS5A protein [half life fell from 18.7 h to 2.7 h]. The proteasome inhibitors, epoxomicin and MG132, significantly abrogated degradation of NS5A protein by ZnMP without affecting levels of NS5A in the absence of ZnMP. Analysis of immunoprecipitates with an anti-ubiquitin antibody revealed polyubiquitination of NS5A, suggesting that ZnMP induces ubiquitination of NS5A protein. In addition, 10 μM of ZnMP reduced HCV replication by ~63% in the Con1 replicon cells, ~70% in J6/JFH1 HCV transfected cells, and ~90% in J6/JFH1 HCV infected cells without affecting cell viability. Conclusions ZnMP produces a rapid and profound down-regulation of the NS5A protein by enhancing its polyubiquitination and proteasome-dependent catabolism. Zinc mesoporphyrin may hold promise as a novel agent to treat HCV infection. PMID:19909748

Hemin potentiates the anti-hepatitis C virus activity of the antimalarial drug artemisinin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paeshuyse, Jan; Coelmont, Lotte; Vliegen, Inge

2006-09-15

We report that the antimalarial drug artemisinin inhibits hepatitis C virus (HCV) replicon replication in a dose-dependent manner in two replicon constructs at concentrations that have no effect on the proliferation of the exponentially growing host cells. The 50% effective concentration (EC{sub 5}) for inhibition of HCV subgenomic replicon replication in Huh 5-2 cells (luciferase assay) by artemisinin was 78 {+-} 21 {mu}M. Hemin, an iron donor, was recently reported to inhibit HCV replicon replication [mediated by inhibition of the viral polymerase (C. Fillebeen, A.M. Rivas-Estilla, M. Bisaillon, P. Ponka, M. Muckenthaler, M.W. Hentze, A.E. Koromilas, K. Pantopoulos, Iron inactivatesmore » the RNA polymerase NS5B and suppresses subgenomic replication of hepatitis C virus, J. Biol. Chem. 280 (2005) 9049-9057.)] at a concentration that had no adverse effect on the host cells. When combined, artemisinin and hemin resulted, over a broad concentration range, in a pronounced synergistic antiviral activity. Also at a concentration (2 {mu}M) that alone had no effect on HCV replication, hemin still potentiated the anti-HCV activity of artemisinin.« less

Very-Low-Density Lipoprotein (VLDL)-Producing and Hepatitis C Virus-Replicating HepG2 Cells Secrete No More Lipoviroparticles than VLDL-Deficient Huh7.5 Cells

PubMed Central

Jammart, Baptiste; Michelet, Maud; Pécheur, Eve-Isabelle; Parent, Romain; Bartosch, Birke; Zoulim, Fabien

2013-01-01

In the plasma samples of hepatitis C virus (HCV)-infected patients, lipoviroparticles (LVPs), defined as (very-) low-density viral particles immunoprecipitated with anti-β-lipoproteins antibodies are observed. This HCV-lipoprotein association has major implications with respect to our understanding of HCV assembly, secretion, and entry. However, cell culture-grown HCV (HCVcc) virions produced in Huh7 cells, which are deficient for very-low-density lipoprotein (VLDL) secretion, are only associated with and dependent on apolipoprotein E (apoE), not apolipoprotein B (apoB), for assembly and infectivity. In contrast to Huh7, HepG2 cells can be stimulated to produce VLDL by both oleic acid treatment and inhibition of the MEK/extracellular signal-regulated kinase (ERK) pathway but are not permissive for persistent HCV replication. Here, we developed a new HCV cell culture model to study the interaction between HCV and lipoproteins, based on engineered HepG2 cells stably replicating a blasticidin-tagged HCV JFH1 strain (JB). Control Huh7.5-JB as well as HepG2-JB cell lines persistently replicated viral RNA and expressed viral proteins with a subcellular colocalization of double-stranded RNA (dsRNA), core, gpE2, and NS5A compatible with virion assembly. The intracellular RNA replication level was increased in HepG2-JB cells upon dimethyl sulfoxide (DMSO) treatment, MEK/ERK inhibition, and NS5A overexpression to a level similar to that observed in Huh7.5-JB cells. Both cell culture systems produced infectious virions, which were surprisingly biophysically and biochemically similar. They floated at similar densities on gradients, contained mainly apoE but not apoB, and were not neutralized by anti-apoB antibodies. This suggests that there is no correlation between the ability of cells to simultaneously replicate HCV as well as secrete VLDL and their capacity to produce LVPs. PMID:23427158

Very-low-density lipoprotein (VLDL)-producing and hepatitis C virus-replicating HepG2 cells secrete no more lipoviroparticles than VLDL-deficient Huh7.5 cells.

PubMed

Jammart, Baptiste; Michelet, Maud; Pécheur, Eve-Isabelle; Parent, Romain; Bartosch, Birke; Zoulim, Fabien; Durantel, David

2013-05-01

In the plasma samples of hepatitis C virus (HCV)-infected patients, lipoviroparticles (LVPs), defined as (very-) low-density viral particles immunoprecipitated with anti-β-lipoproteins antibodies are observed. This HCV-lipoprotein association has major implications with respect to our understanding of HCV assembly, secretion, and entry. However, cell culture-grown HCV (HCVcc) virions produced in Huh7 cells, which are deficient for very-low-density lipoprotein (VLDL) secretion, are only associated with and dependent on apolipoprotein E (apoE), not apolipoprotein B (apoB), for assembly and infectivity. In contrast to Huh7, HepG2 cells can be stimulated to produce VLDL by both oleic acid treatment and inhibition of the MEK/extracellular signal-regulated kinase (ERK) pathway but are not permissive for persistent HCV replication. Here, we developed a new HCV cell culture model to study the interaction between HCV and lipoproteins, based on engineered HepG2 cells stably replicating a blasticidin-tagged HCV JFH1 strain (JB). Control Huh7.5-JB as well as HepG2-JB cell lines persistently replicated viral RNA and expressed viral proteins with a subcellular colocalization of double-stranded RNA (dsRNA), core, gpE2, and NS5A compatible with virion assembly. The intracellular RNA replication level was increased in HepG2-JB cells upon dimethyl sulfoxide (DMSO) treatment, MEK/ERK inhibition, and NS5A overexpression to a level similar to that observed in Huh7.5-JB cells. Both cell culture systems produced infectious virions, which were surprisingly biophysically and biochemically similar. They floated at similar densities on gradients, contained mainly apoE but not apoB, and were not neutralized by anti-apoB antibodies. This suggests that there is no correlation between the ability of cells to simultaneously replicate HCV as well as secrete VLDL and their capacity to produce LVPs.

Persistent replication of a hepatitis C virus genotype 1b-based chimeric clone carrying E1, E2 and p6 regions from GB virus B in a New World monkey.

PubMed

Suzuki, Saori; Mori, Ken-Ichi; Higashino, Atsunori; Iwasaki, Yuki; Yasutomi, Yasuhiro; Maki, Noboru; Akari, Hirofumi

2016-01-01

The development of effective hepatitis C virus (HCV) vaccines is essential for the prevention of further HCV dissemination, especially in developing countries. Therefore the aim of this study is to establish a feasible and immunocompetent surrogate animal model of HCV infection that will help in evaluation of the protective efficacy of newly developing HCV vaccine candidates. To circumvent the narrow host range of HCV, an HCV genotype 1b-based chimeric clone carrying E1, E2 and p6 regions from GB virus B (GBV-B), which is closely related to HCV, was generated. The chimera between HCV and GBV-B, named HCV/G, replicated more efficiently as compared with the HCV clone in primary marmoset hepatocytes. Furthermore, it was found that the chimera persistently replicated in a tamarin for more than 2 years after intrahepatic inoculation of the chimeric RNA. Although relatively low (<200 copies/mL), the viral RNA loads in plasma were detectable intermittently during the observation period. Of note, the chimeric RNA was found in the pellet fraction obtained by ultracentrifugation of the plasma at 73 weeks, indicating production of the chimeric virus. Our results will help establish a novel non-human primate model for HCV infection on the basis of the HCV/G chimera in the major framework of the HCV genome. © 2015 The Societies and John Wiley & Sons Australia, Ltd.

Detection of hepatitis C virus sequences in brain tissue obtained in recurrent hepatitis C after liver transplantation.

PubMed

Vargas, Hugo E; Laskus, Tomasz; Radkowski, Marek; Wilkinson, Jeff; Balan, Vijay; Douglas, David D; Harrison, M Edwyn; Mulligan, David C; Olden, Kevin; Adair, Debra; Rakela, Jorge

2002-11-01

Patients with chronic hepatitis C frequently report tiredness, easy fatigability, and depression. The aim of this study is to determine whether hepatitis C virus (HCV) replication could be found in brain tissue in patients with hepatitis C and depression. We report two patients with recurrent hepatitis C after liver transplantation who also developed severe depression. One patient died of multiorgan failure and the other, septicemia caused by Staphylococcus aureussis. Both patients had evidence of severe hepatitis C recurrence with features of cholestatic fibrosing hepatitis. We were able to study samples of their central nervous system obtained at autopsy for evidence of HCV replication. The presence of HCV RNA-negative strand, which is the viral replicative form, was determined by strand-specific Tth-based reverse-transcriptase polymerase chain reaction. Viral sequences were compared by means of single-strand conformation polymorphism and direct sequencing. HCV RNA-negative strands were found in subcortical white matter from one patient and cerebral cortex from the other patient. HCV RNA-negative strands amplified from brain tissue differed by several nucleotide substitutions from serum consensus sequences in the 5' untranslated region. These findings support the concept of HCV neuroinvasion, and we speculate that it may provide a biological substrate to neuropsychiatric disorders observed in patients with chronic hepatitis C. The exact lineage of cells permissive for HCV replication and the possible interaction between viral replication and cerebral function that may lead to depression remain to be elucidated.

Kushenin induces the apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Yi; Chen, Na; Liu, Xiaojing

With the increased burden induced by HCV, there is an urgent need to develop better-tolerated agents with good safety. In this study, we evaluated the anti-HCV capability of kushenin, as well as the possible mechanism to Huh7.5-HCV cells. The results demonstrated that kushenin significantly inhibited the HCV-RNA level. Similarly, the expression of HCV-specific protein NS5A was also decreased. Molecular docking results displayed that kushenin bonded well to the active pockets of HCV NS5A, further confirming the effects of kushenin on HCV replication. Coimmunoprecipitation assay determined that kushenin suppressed the interaction between PI3K and NS5A in HCV-replicon cells. Furthermore, kushenin exertedmore » an obviously induced function on HCV-replicon cells apoptosis by inhibiting PI3K-Akt-mTOR pathway, which could be ameliorated by the specific activator IGF-1 addition. Taken together, kushenin possesses the ability to inhibit HCV replication, and contributes to the increased apoptosis of HCV-infected cells by blocking the PI3K-Akt-mTOR pathway via inhibiting NS5A. Our results provide important evidence for a better understanding of the pathogenesis of HCV infection, and suggest that kushenin has the potential to treat HCV disease. - Highlights: • Kushenin inhibits HCV replication. • Kushenin bonds directly to NS5A protein. • Kushenin induces the apoptosis of HCV-infected cells. • kushenin suppresses the interaction between PI3K and NS5A. • Kushenin inhibits PI3K-Akt-mTOR pathway.« less

PML tumor suppressor protein is required for HCV production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuroki, Misao; Research Fellow of the Japan Society for the Promotion of Science; Center for AIDS Research, Kumamoto University, Kumamoto 860-0811

2013-01-11

Highlights: Black-Right-Pointing-Pointer PML tumor suppressor protein is required for HCV production. Black-Right-Pointing-Pointer PML is dispensable for HCV RNA replication. Black-Right-Pointing-Pointer HCV could not alter formation of PML-NBs. Black-Right-Pointing-Pointer INI1 and DDX5, PML-related proteins, are involved in HCV life cycle. -- Abstract: PML tumor suppressor protein, which forms discrete nuclear structures termed PML-nuclear bodies, has been associated with several cellular functions, including cell proliferation, apoptosis and antiviral defense. Recently, it was reported that the HCV core protein colocalizes with PML in PML-NBs and abrogates the PML function through interaction with PML. However, role(s) of PML in HCV life cycle is unknown.more » To test whether or not PML affects HCV life cycle, we examined the level of secreted HCV core and the infectivity of HCV in the culture supernatants as well as the level of HCV RNA in HuH-7-derived RSc cells, in which HCV-JFH1 can infect and efficiently replicate, stably expressing short hairpin RNA targeted to PML. In this context, the level of secreted HCV core and the infectivity in the supernatants from PML knockdown cells was remarkably reduced, whereas the level of HCV RNA in the PML knockdown cells was not significantly affected in spite of very effective knockdown of PML. In fact, we showed that PML is unrelated to HCV RNA replication using the subgenomic HCV-JFH1 replicon RNA, JRN/3-5B. Furthermore, the infectivity of HCV-like particle in the culture supernatants was significantly reduced in PML knockdown JRN/3-5B cells expressing core to NS2 coding region of HCV-JFH1 genome using the trans-packaging system. Finally, we also demonstrated that INI1 and DDX5, the PML-related proteins, are involved in HCV production. Taken together, these findings suggest that PML is required for HCV production.« less

microRNA-122 target sites in the hepatitis C virus RNA NS5B coding region and 3' untranslated region: function in replication and influence of RNA secondary structure.

PubMed

Gerresheim, Gesche K; Dünnes, Nadia; Nieder-Röhrmann, Anika; Shalamova, Lyudmila A; Fricke, Markus; Hofacker, Ivo; Höner Zu Siederdissen, Christian; Marz, Manja; Niepmann, Michael

2017-02-01

We have analyzed the binding of the liver-specific microRNA-122 (miR-122) to three conserved target sites of hepatitis C virus (HCV) RNA, two in the non-structural protein 5B (NS5B) coding region and one in the 3' untranslated region (3'UTR). miR-122 binding efficiency strongly depends on target site accessibility under conditions when the range of flanking sequences available for the formation of local RNA secondary structures changes. Our results indicate that the particular sequence feature that contributes most to the correlation between target site accessibility and binding strength varies between different target sites. This suggests that the dynamics of miRNA/Ago2 binding not only depends on the target site itself but also on flanking sequence context to a considerable extent, in particular in a small viral genome in which strong selection constraints act on coding sequence and overlapping cis-signals and model the accessibility of cis-signals. In full-length genomes, single and combination mutations in the miR-122 target sites reveal that site 5B.2 is positively involved in regulating overall genome replication efficiency, whereas mutation of site 5B.3 showed a weaker effect. Mutation of the 3'UTR site and double or triple mutants showed no significant overall effect on genome replication, whereas in a translation reporter RNA, the 3'UTR target site inhibits translation directed by the HCV 5'UTR. Thus, the miR-122 target sites in the 3'-region of the HCV genome are involved in a complex interplay in regulating different steps of the HCV replication cycle.

Methamphetamine enhances Hepatitis C virus replication in human hepatocytes

PubMed Central

Ye, L.; Peng, J. S.; Wang, X.; Wang, Y. J.; Luo, G. X.; Ho, W. Z.

2009-01-01

SUMMARY Very little is known about the interactions between hepatitis C virus (HCV) and methamphetamine, which is a highly abused psychostimulant and a known risk factor for human immunodeficiency virus (HIV)/HCV infection. This study examined whether methamphetamine has the ability to inhibit innate immunity in the host cells, facilitating HCV replication in human hepatocytes. Methamphetamine inhibited intracellular interferon alpha expression in human hepatocytes, which was associated with the increase in HCV replication. In addition, methamphetamine also compromised the anti-HCV effect of recombinant interferon alpha. Further investigation of mechanism(s) responsible for the methamphetamine action revealed that methamphetamine was able to inhibit the expression of the signal transducer and activator of transcription 1, a key modulator in interferon-mediated immune and biological responses. Methamphetamine also down-regulated the expression of interferon regulatory factor-5, a crucial transcriptional factor that activates the interferon pathway. These in vitro findings that methamphetamine compromises interferon alpha-mediated innate immunity against HCV infection indicate that methamphetamine may have a cofactor role in the immunopathogenesis of HCV disease. PMID:18307590

NS5A inhibitors unmask differences in functional replicase complex half-life between different hepatitis C virus strains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benzine, Tiffany; Brandt, Ryan; Lovell, William C.

We synthesized the Hepatitis C virus (HCV) RNA by the replicase complex (RC), a macromolecular assembly composed of viral non-structural proteins and cellular co-factors. Inhibitors of the HCV NS5A protein block formation of new RCs but do not affect RNA synthesis by preformed RCs. Without new RC formation, existing RCs turn over and are eventually lost from the cell. We aimed to use NS5A inhibitors to estimate the half-life of the functional RC of HCV. We compared different cell culture-infectious strains of HCV that may be grouped based on their sensitivity to lipid peroxidation: robustly replicating, lipid peroxidation resistant (LPOmore » R) viruses (e.g. JFH-1 or H77D) and more slowly replicating, lipid peroxidation sensitive (LPO S) viruses (e.g. H77S.3 and N.2). Furthermore, in luciferase assays, LPO S HCV strains declined under NS5A inhibitor therapy with much slower kinetics compared to LPO R HCV strains. This difference in rate of decline was not observed for inhibitors of the NS5B RNAdependent RNA polymerase suggesting that the difference was not simply a consequence of differences in RNA stability. In further analyses, we compared two isoclonal HCV variants: the LPO S H77S.3 and the LPO R H77D that differ only by 12 amino acids. Differences in rate of decline between H77S.3 and H77D following NS5A inhibitor addition were not due to amino acid sequences in NS5A but rather due to a combination of amino acid differences in the non-structural proteins that make up the HCV RC. The mathematical modeling of intracellular HCV RNA dynamics suggested that differences in RC stability (half-lives of 3.5 and 9.9 hours, for H77D and H77S.3, respectively) are responsible for the different kinetics of antiviral suppression between LPO S and LPO R viruses. In nascent RNA capture assays, the rate of RNA synthesis decline following NS5A inhibitor addition was significantly faster for H77D compared to H77S.3 indicating different half-lives of functional RCs.« less

NS5A inhibitors unmask differences in functional replicase complex half-life between different hepatitis C virus strains

DOE PAGES

Benzine, Tiffany; Brandt, Ryan; Lovell, William C.; ...

2017-06-08

We synthesized the Hepatitis C virus (HCV) RNA by the replicase complex (RC), a macromolecular assembly composed of viral non-structural proteins and cellular co-factors. Inhibitors of the HCV NS5A protein block formation of new RCs but do not affect RNA synthesis by preformed RCs. Without new RC formation, existing RCs turn over and are eventually lost from the cell. We aimed to use NS5A inhibitors to estimate the half-life of the functional RC of HCV. We compared different cell culture-infectious strains of HCV that may be grouped based on their sensitivity to lipid peroxidation: robustly replicating, lipid peroxidation resistant (LPOmore » R) viruses (e.g. JFH-1 or H77D) and more slowly replicating, lipid peroxidation sensitive (LPO S) viruses (e.g. H77S.3 and N.2). Furthermore, in luciferase assays, LPO S HCV strains declined under NS5A inhibitor therapy with much slower kinetics compared to LPO R HCV strains. This difference in rate of decline was not observed for inhibitors of the NS5B RNAdependent RNA polymerase suggesting that the difference was not simply a consequence of differences in RNA stability. In further analyses, we compared two isoclonal HCV variants: the LPO S H77S.3 and the LPO R H77D that differ only by 12 amino acids. Differences in rate of decline between H77S.3 and H77D following NS5A inhibitor addition were not due to amino acid sequences in NS5A but rather due to a combination of amino acid differences in the non-structural proteins that make up the HCV RC. The mathematical modeling of intracellular HCV RNA dynamics suggested that differences in RC stability (half-lives of 3.5 and 9.9 hours, for H77D and H77S.3, respectively) are responsible for the different kinetics of antiviral suppression between LPO S and LPO R viruses. In nascent RNA capture assays, the rate of RNA synthesis decline following NS5A inhibitor addition was significantly faster for H77D compared to H77S.3 indicating different half-lives of functional RCs.« less

Cyclophilin B stimulates RNA synthesis by the HCV RNA dependent RNA polymerase

PubMed Central

Heck, Julie A.; Meng, Xiao; Frick, David N.

2009-01-01

Cyclophilins are cellular peptidyl isomerases that have been implicated in regulating hepatitis C virus (HCV) replication. Cyclophilin B (CypB) is a target of cyclosporin A (CsA), an immunosuppressive drug recently shown to suppress HCV replication in cell culture. Watashi et al. recently demonstrated that CypB is important for efficient HCV replication, and proposed that it mediates the anti-HCV effects of CsA through an interaction with NS5B (Mol. Cell 19:111). We examined the effects of purified CypB proteins on the enzymatic activity of NS5B. Recombinant CypB purified from insect cells directly stimulated NS5B-catalyzed RNA synthesis. CypB increased RNA synthesis by NS5B derived from genotype 1a, 1b, and 2a HCV strains. Stimulation appears to arise from an increase in productive RNA binding. NS5B residue Pro540, a previously proposed target of CypB peptidyl-prolyl isomerase activity, is not required for stimulation of RNA synthesis. PMID:19174155

Treating hepatitis C: can you teach old dogs new tricks?

PubMed

Rice, Charles M; You, Shihyun

2005-12-01

Viruses depend on host-derived factors for their efficient genome replication. Here, we demonstrate that a cellular peptidyl-prolyl cis-trans isomerase (PPIase), cyclophilin B (CyPB), is critical for the efficient replication of the hepatitis C virus genome. CyPB interacted with the HCV RNA polymerase NS5B to directly stimulate its RNA binding activity. Both the RNA interference (RNAi)-mediated reduction of endogenous CyPB expression and the induced loss of NS5B binding to CyPB decreased the levels of HCV replication. Thus, CyPB functions as a stimulatory regulator of NS5B in HCV replication machinery. This regulation mechanism for viral replication identifies CyPB as a target for antiviral therapeutic strategies.

Nonstructural 3 Protein of Hepatitis C Virus Modulates the Tribbles Homolog 3/Akt Signaling Pathway for Persistent Viral Infection

PubMed Central

Tran, Si C.; Pham, Tu M.; Nguyen, Lam N.; Park, Eun-Mee; Lim, Yun-Sook

2016-01-01

ABSTRACT Hepatitis C virus (HCV) infection often causes chronic hepatitis, liver cirrhosis, and ultimately hepatocellular carcinoma. However, the mechanisms underlying HCV-induced liver pathogenesis are still not fully understood. By transcriptome sequencing (RNA-Seq) analysis, we recently identified host genes that were significantly differentially expressed in cell culture-grown HCV (HCVcc)-infected cells. Of these, tribbles homolog 3 (TRIB3) was selected for further characterization. TRIB3 was initially identified as a binding partner of protein kinase B (also known as Akt). TRIB3 blocks the phosphorylation of Akt and induces apoptosis under endoplasmic reticulum (ER) stress conditions. HCV has been shown to enhance Akt phosphorylation for its own propagation. In the present study, we demonstrated that both mRNA and protein levels of TRIB3 were increased in the context of HCV replication. We further showed that promoter activity of TRIB3 was increased by HCV-induced ER stress. Silencing of TRIB3 resulted in increased RNA and protein levels of HCV, whereas overexpression of TRIB3 decreased HCV replication. By employing an HCV pseudoparticle entry assay, we further showed that TRIB3 was a negative host factor involved in HCV entry. Both in vitro binding and immunoprecipitation assays demonstrated that HCV NS3 specifically interacted with TRIB3. Consequently, the association of TRIB3 and Akt was disrupted by HCV NS3, and thus, TRIB3-Akt signaling was impaired in HCV-infected cells. Moreover, HCV modulated TRIB3 to promote extracellular signal-regulated kinase (ERK) phosphorylation, activator protein 1 (AP-1) activity, and cell migration. Collectively, these data indicate that HCV exploits the TRIB3-Akt signaling pathway to promote persistent viral infection and may contribute to HCV-mediated pathogenesis. IMPORTANCE TRIB3 is a pseudokinase protein that acts as an adaptor in signaling pathways for important cellular processes. So far, the functional involvement of TRIB3 in virus-infected cells has not yet been demonstrated. We showed that both mRNA and protein expression levels of TRIB3 were increased in the context of HCV RNA replication. Gene silencing of TRIB3 increased HCV RNA and protein levels, and thus, overexpression of TRIB3 decreased HCV replication. TRIB3 is known to promote apoptosis by negatively regulating the Akt signaling pathway under ER stress conditions. Most importantly, we demonstrated that the TRIB3-Akt signaling pathway was disrupted by NS3 in HCV-infected cells. These data provide evidence that HCV modulates the TRIB3-Akt signaling pathway to establish persistent viral infection. PMID:27252525

Infectious Hepatitis C Virus Pseudo-particles Containing Functional E1–E2 Envelope Protein Complexes

PubMed Central

Bartosch, Birke; Dubuisson, Jean; Cosset, François-Loïc

2003-01-01

The study of hepatitis C virus (HCV), a major cause of chronic liver disease, has been hampered by the lack of a cell culture system supporting its replication. Here, we have successfully generated infectious pseudo-particles that were assembled by displaying unmodified and functional HCV glycoproteins onto retroviral and lentiviral core particles. The presence of a green fluorescent protein marker gene packaged within these HCV pseudo-particles allowed reliable and fast determination of infectivity mediated by the HCV glycoproteins. Primary hepatocytes as well as hepato-carcinoma cells were found to be the major targets of infection in vitro. High infectivity of the pseudo-particles required both E1 and E2 HCV glycoproteins, and was neutralized by sera from HCV-infected patients and by some anti-E2 monoclonal antibodies. In addition, these pseudo-particles allowed investigation of the role of putative HCV receptors. Although our results tend to confirm their involvement, they provide evidence that neither LDLr nor CD81 is sufficient to mediate HCV cell entry. Altogether, these studies indicate that these pseudo-particles may mimic the early infection steps of parental HCV and will be suitable for the development of much needed new antiviral therapies. PMID:12615904

The folding of the hepatitis C virus internal ribosome entry site depends on the 3′-end of the viral genome

PubMed Central

Romero-López, Cristina; Barroso-delJesus, Alicia; García-Sacristán, Ana; Briones, Carlos; Berzal-Herranz, Alfredo

2012-01-01

Hepatitis C virus (HCV) translation initiation is directed by an internal ribosome entry site (IRES) and regulated by distant regions at the 3′-end of the viral genome. Through a combination of improved RNA chemical probing methods, SHAPE structural analysis and screening of RNA accessibility using antisense oligonucleotide microarrays, here, we show that HCV IRES folding is fine-tuned by the genomic 3′-end. The essential IRES subdomains IIIb and IIId, and domain IV, adopted a different conformation in the presence of the cis-acting replication element and/or the 3′-untranslatable region compared to that taken up in their absence. Importantly, many of the observed changes involved significant decreases in the dimethyl sulfate or N-methyl-isatoic anhydride reactivity profiles at subdomains IIIb and IIId, while domain IV appeared as a more flexible element. These observations were additionally confirmed in a replication-competent RNA molecule. Significantly, protein factors are not required for these conformational differences to be made manifest. Our results suggest that a complex, direct and long-distance RNA–RNA interaction network plays an important role in the regulation of HCV translation and replication, as well as in the switching between different steps of the viral cycle. PMID:23066110

Inhibition of Hepatitis C Virus Replication by Intracellular Delivery of Multiple siRNAs by Nanosomes

PubMed Central

Chandra, Partha K; Kundu, Anup K; Hazari, Sidhartha; Chandra, Sruti; Bao, Lili; Ooms, Tara; Morris, Gilbert F; Wu, Tong; Mandal, Tarun K; Dash, Srikanta

2012-01-01

Sustained antiviral responses of chronic hepatitis C virus (HCV) infection have improved recently by the use of direct-acting antiviral agents along with interferon (IFN)-α and ribavirin. However, the emergence of drug-resistant variants is expected to be a major problem. We describe here a novel combinatorial small interfering RNA (siRNA) nanosome-based antiviral approach to clear HCV infection. Multiple siRNAs targeted to the highly conserved 5′-untranslated region (UTR) of the HCV genome were synthesized and encapsulated into lipid nanoparticles called nanosomes. We show that siRNA can be repeatedly delivered to 100% of cells in culture using nanosomes without toxicity. Six siRNAs dramatically reduced HCV replication in both the replicon and infectious cell culture model. Repeated treatments with two siRNAs were better than a single siRNA treatment in minimizing the development of an escape mutant, resulting in rapid inhibition of viral replication. Systemic administration of combinatorial siRNA-nanosomes is well tolerated in BALB/c mice without liver injury or histological toxicity. As a proof-of-principle, we showed that systemic injections of siRNA nanosomes significantly reduced HCV replication in a liver tumor-xenotransplant mouse model of HCV. Our results indicate that systemic delivery of combinatorial siRNA nanosomes can be used to minimize the development of escape mutants and inhibition of HCV infection. PMID:22617108

Complete replication of hepatitis B virus and hepatitis C virus in a newly developed hepatoma cell line.

PubMed

Yang, Darong; Zuo, Chaohui; Wang, Xiaohong; Meng, Xianghe; Xue, Binbin; Liu, Nianli; Yu, Rong; Qin, Yuwen; Gao, Yimin; Wang, Qiuping; Hu, Jun; Wang, Ling; Zhou, Zebin; Liu, Bing; Tan, Deming; Guan, Yang; Zhu, Haizhen

2014-04-01

The absence of a robust cell culture system for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection has limited the analysis of the virus lifecycle and drug discovery. We have established a hepatoma cell line, HLCZ01, the first cell line, to the authors' knowledge, supporting the entire lifecycle of both HBV and HCV. HBV surface antigen (HBsAg)-positive particles can be observed in the supernatant and the lumen of the endoplasmic reticulum of the cells via electron microscopy. Interestingly, HBV and HCV clinical isolates propagate in HLCZ01 cells. Both viruses replicate in the cells without evidence of overt interference. HBV and HCV entry are blocked by antibodies against HBsAg and human CD81, respectively, and the replication of HBV and HCV is inhibited by antivirals. HLCZ01 cells mount an innate immune response to virus infection. The cell line provides a powerful tool for exploring the mechanisms of virus entry and replication and the interaction between host and virus, facilitating the development of novel antiviral agents and vaccines.

Identification of HNRNPK as Regulator of Hepatitis C Virus Particle Production

PubMed Central

Poenisch, Marion; Metz, Philippe; Blankenburg, Hagen; Ruggieri, Alessia; Lee, Ji-Young; Rupp, Daniel; Rebhan, Ilka; Diederich, Kathrin; Kaderali, Lars; Domingues, Francisco S.; Albrecht, Mario; Lohmann, Volker; Erfle, Holger; Bartenschlager, Ralf

2015-01-01

Hepatitis C virus (HCV) is a major cause of chronic liver disease affecting around 130 million people worldwide. While great progress has been made to define the principle steps of the viral life cycle, detailed knowledge how HCV interacts with its host cells is still limited. To overcome this limitation we conducted a comprehensive whole-virus RNA interference-based screen and identified 40 host dependency and 16 host restriction factors involved in HCV entry/replication or assembly/release. Of these factors, heterogeneous nuclear ribonucleoprotein K (HNRNPK) was found to suppress HCV particle production without affecting viral RNA replication. This suppression of virus production was specific to HCV, independent from assembly competence and genotype, and not found with the related Dengue virus. By using a knock-down rescue approach we identified the domains within HNRNPK required for suppression of HCV particle production. Importantly, HNRNPK was found to interact specifically with HCV RNA and this interaction was impaired by mutations that also reduced the ability to suppress HCV particle production. Finally, we found that in HCV-infected cells, subcellular distribution of HNRNPK was altered; the protein was recruited to sites in close proximity of lipid droplets and colocalized with core protein as well as HCV plus-strand RNA, which was not the case with HNRNPK variants unable to suppress HCV virion formation. These results suggest that HNRNPK might determine efficiency of HCV particle production by limiting the availability of viral RNA for incorporation into virions. This study adds a new function to HNRNPK that acts as central hub in the replication cycle of multiple other viruses. PMID:25569684

Hepatitis C Virus Replication Depends on Endosomal Cholesterol Homeostasis.

PubMed

Stoeck, Ina Karen; Lee, Ji-Young; Tabata, Keisuke; Romero-Brey, Inés; Paul, David; Schult, Philipp; Lohmann, Volker; Kaderali, Lars; Bartenschlager, Ralf

2018-01-01

Similar to other positive-strand RNA viruses, hepatitis C virus (HCV) causes massive rearrangements of intracellular membranes, resulting in a membranous web (MW) composed of predominantly double-membrane vesicles (DMVs), the presumed sites of RNA replication. DMVs are enriched for cholesterol, but mechanistic details on the source and recruitment of cholesterol to the viral replication organelle are only partially known. Here we focused on selected lipid transfer proteins implicated in direct lipid transfer at various endoplasmic reticulum (ER)-membrane contact sites. RNA interference (RNAi)-mediated knockdown identified several hitherto unknown HCV dependency factors, such as steroidogenic acute regulatory protein-related lipid transfer domain protein 3 (STARD3), oxysterol-binding protein-related protein 1A and -B (OSBPL1A and -B), and Niemann-Pick-type C1 (NPC1), all residing at late endosome and lysosome membranes and required for efficient HCV RNA replication but not for replication of the closely related dengue virus. Focusing on NPC1, we found that knockdown or pharmacological inhibition caused cholesterol entrapment in lysosomal vesicles concomitant with decreased cholesterol abundance at sites containing the viral replicase factor NS5A. In untreated HCV-infected cells, unesterified cholesterol accumulated at the perinuclear region, partially colocalizing with NS5A at DMVs, arguing for NPC1-mediated endosomal cholesterol transport to the viral replication organelle. Consistent with cholesterol being an important structural component of DMVs, reducing NPC1-dependent endosomal cholesterol transport impaired MW integrity. This suggests that HCV usurps lipid transfer proteins, such as NPC1, at ER-late endosome/lysosome membrane contact sites to recruit cholesterol to the viral replication organelle, where it contributes to MW functionality. IMPORTANCE A key feature of the replication of positive-strand RNA viruses is the rearrangement of the host cell endomembrane system to produce a membranous replication organelle (RO). The underlying mechanisms are far from being elucidated fully. In this report, we provide evidence that HCV RNA replication depends on functional lipid transport along the endosomal-lysosomal pathway that is mediated by several lipid transfer proteins, such as the Niemann-Pick type C1 (NPC1) protein. Pharmacological inhibition of NPC1 function reduced viral replication, impaired the transport of cholesterol to the viral replication organelle, and altered organelle morphology. Besides NPC1, our study reports the importance of additional endosomal and lysosomal lipid transfer proteins required for viral replication, thus contributing to our understanding of how HCV manipulates their function in order to generate a membranous replication organelle. These results might have implications for the biogenesis of replication organelles of other positive-strand RNA viruses. Copyright © 2017 American Society for Microbiology.

Evidence for Protection against Chronic Hepatitis C Virus Infection in Chimpanzees by Immunization with Replicating Recombinant Vaccinia Virus▿

PubMed Central

Youn, Jin-Won; Hu, Yu-Wen; Tricoche, Nancy; Pfahler, Wolfram; Shata, Mohamed Tarek; Dreux, Marlene; Cosset, François-Loic; Folgori, Antonella; Lee, Dong-Hun; Brotman, Betsy; Prince, Alfred M.

2008-01-01

Given the failures of nonreplicating vaccines against chronic hepatitis C virus (HCV) infection, we hypothesized that a replicating viral vector may provide protective immunity. Four chimpanzees were immunized transdermally twice with recombinant vaccinia viruses (rVV) expressing HCV genes. After challenge with 24 50% chimpanzee infective doses of homologous HCV, the two control animals that had received only the parental VV developed chronic HCV infection. All four immunized animals resolved HCV infection. The difference in the rate of chronicity between the immunized and the control animals was close to statistical significance (P = 0.067). Immunized animals developed vigorous gamma interferon enzyme-linked immunospot responses and moderate proliferative responses. To investigate cross-genotype protection, the immunized recovered chimpanzees were challenged with a pool of six major HCV genotypes. During the acute phase after the multigenotype challenge, all animals had high-titer viremia in which genotype 4 dominated (87%), followed by genotype 5 (13%). However, after fluctuating low-level viremia, the viremia finally turned negative or persisted at very low levels. This study suggests the potential efficacy of replicating recombinant vaccinia virus-based immunization against chronic HCV infection. PMID:18753204

cis-acting RNA elements required for replication of bovine viral diarrhea virus-hepatitis C virus 5' nontranslated region chimeras.

PubMed Central

Frolov, I; McBride, M S; Rice, C M

1998-01-01

Pestiviruses, such as bovine viral diarrhea virus (BVDV), share many similarities with hepatitis C virus (HCV) yet are more amenable to virologic and genetic analysis. For both BVDV and HCV, translation is initiated via an internal ribosome entry site (IRES). Besides IRES function, the viral 5' nontranslated regions (NTRs) may also contain cis-acting RNA elements important for viral replication. A series of chimeric RNAs were used to examine the function of the BVDV 5' NTR. Our results show that: (1) the HCV and the encephalomyocarditis virus (EMCV) IRES element can functionally replace that of BVDV; (2) two 5' terminal hairpins in BVDV genomic RNA are important for efficient replication; (3) replacement of the entire BVDV 5' NTR with those of HCV or EMCV leads to severely impaired replication; (4) such replacement chimeras are unstable and efficiently replicating pseudorevertants arise; (5) pseudorevertant mutations involve deletion of 5' sequences and/or acquisition of novel 5' sequences such that the 5' terminal 3-4 bases of BVDV genome RNA are restored. Besides providing new insight into functional elements in the BVDV 5' NTR, these chimeras may prove useful as pestivirus vaccines and for screening and evaluation of anti-HCV IRES antivirals. PMID:9814762

Preclinical Evaluation of An Anti-HCV miRNA Cluster for Treatment of HCV Infection

PubMed Central

Yang, Xiao; Marcucci, Katherine; Anguela, Xavier; Couto, Linda B.

2013-01-01

We developed a strategy to treat hepatitis C virus (HCV) infection by replacing five endogenous microRNA (miRNA) sequences of a natural miRNA cluster (miR-17–92) with sequences that are complementary to the HCV genome. This miRNA cluster (HCV-miR-Cluster 5) is delivered to cells using adeno-associated virus (AAV) vectors and the miRNAs are expressed in the liver, the site of HCV replication and assembly. AAV-HCV-miR-Cluster 5 inhibited bona fide HCV replication in vitro by up to 95% within 2 days, and the spread of HCV to uninfected cells was prevented by continuous expression of the anti-HCV miRNAs. Furthermore, the number of cells harboring HCV RNA replicons decreased dramatically by sustained expression of the anti-HCV miRNAs, suggesting that the vector is capable of curing cells of HCV. Delivery of AAV-HCV-miR-Cluster 5 to mice resulted in efficient transfer of the miRNA gene cluster and expression of all five miRNAs in liver tissue, at levels up to 1,300 copies/cell. These levels achieved up to 98% gene silencing of cognate HCV sequences, and no liver toxicity was observed, supporting the safety of this approach. Therefore, AAV-HCV-miR-Cluster 5 represents a different paradigm for the treatment of HCV infection. PMID:23295950

Hepatitis C virus inhibitor synergism suggests multistep interactions between heat-shock protein 90 and hepatitis C virus replication

PubMed Central

Kubota, Naoko; Nomoto, Masataka; Hwang, Gi-Wook; Watanabe, Toshihiko; Kohara, Michinori; Wakita, Takaji; Naganuma, Akira; Kuge, Shusuke

2016-01-01

AIM: To address the effect of heat-shock protein 90 (HSP90) inhibitors on the release of the hepatitis C virus (HCV), a cell culture-derived HCV (JFH1/HCVcc) from Huh-7 cells was examined. METHODS: We quantified both the intracellular and extracellular (culture medium) levels of the components (RNA and core) of JFH-1/HCVcc. The intracellular HCV RNA and core levels were determined after the JFH1/HCVcc-infected Huh-7 cells were treated with radicicol for 36 h. The extracellular HCV RNA and core protein levels were determined from the medium of the last 24 h of radicicol treatment. To determine the possible role of the HSP90 inhibitor in HCV release, we examined the effect of a combined application of low doses of the HSP90 inhibitor radicicol and the RNA replication inhibitors cyclosporin A (CsA) or interferon. Finally, we statistically examined the combined effect of radicicol and CsA using the combination index (CI) and graphical representation proposed by Chou and Talalay. RESULTS: We found that the HSP90 inhibitors had greater inhibitory effects on the HCV RNA and core protein levels measured in the medium than inside the cells. This inhibitory effect was observed in the presence of a low level of a known RNA replication inhibitor (CsA or interferon-α). Treating the cells with a combination of radicicol and cyclosporin A for 24 h resulted in significant synergy (CI < 1) that affected the release of both the viral RNA and the core protein. CONCLUSION: In addition to having an inhibitory effect on RNA replication, HSP90 inhibitors may interfere with an HCV replication step that occurs after the synthesis of viral RNA, such as assembly and release. PMID:26925202

A novel anticancer agent ARC antagonizes HIV-1 and HCV.

PubMed

Nekhai, S; Bhat, U G; Ammosova, T; Radhakrishnan, S K; Jerebtsova, M; Niu, X; Foster, A; Layden, T J; Gartel, A L

2007-05-31

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) pose major public health concerns worldwide. HCV is clearly associated with the occurrence of hepatocellular carcinoma, and recently HIV infection has also been linked to the development of a multitude of cancers. Previously, we identified a novel nucleoside analog transcriptional inhibitor ARC (4-amino-6-hydrazino-7-beta-D-ribofuranosyl-7H-pyrrolo[2,3-d]-pyrimidine-5-carboxamide) that exhibited proapoptotic and antiangiogenic properties in vitro. Here, we evaluated the effect of ARC on HIV-1 transcription and HCV replication. Using reporter assays, we found that ARC inhibited HIV-1 Tat-based transactivation in different cell systems. Also, using hepatoma cells that harbor subgenomic and full-length replicons of HCV, we found that ARC inhibited HCV replication. Together, our data indicate that ARC could be a promising candidate for the development of antiviral therapeutics against HIV and HCV.

Different mechanisms of hepatitis C virus RNA polymerase activation by cyclophilin A and B in vitro.

PubMed

Weng, Leiyun; Tian, Xiao; Gao, Yayi; Watashi, Koichi; Shimotohno, Kunitada; Wakita, Takaji; Kohara, Michinori; Toyoda, Tetsuya

2012-12-01

Cyclophilins (CyPs) are cellular proteins that are essential to hepatitis C virus (HCV) replication. Since cyclosporine A was discovered to inhibit HCV infection, the CyP pathway contributing to HCV replication is a potential attractive stratagem for controlling HCV infection. Among them, CyPA is accepted to interact with HCV nonstructural protein (NS) 5A, although interaction of CyPB and NS5B, an RNA-dependent RNA polymerase (RdRp), was proposed first. CyPA, CyPB, and HCV RdRp were expressed in bacteria and purified using combination column chromatography. HCV RdRp activity was analyzed in vitro with purified CyPA and CyPB. CyPA at a high concentration (50× higher than that of RdRp) but not at low concentration activated HCV RdRp. CyPB had an allosteric effect on genotype 1b RdRp activation. CyPB showed genotype specificity and activated genotype 1b and J6CF (2a) RdRps but not genotype 1a or JFH1 (2a) RdRps. CyPA activated RdRps of genotypes 1a, 1b, and 2a. CyPB may also support HCV genotype 1b replication within the infected cells, although its knockdown effect on HCV 1b replicon activity was controversial in earlier reports. CyPA activated HCV RdRp at the early stages of transcription, including template RNA binding. CyPB also activated genotype 1b RdRp. However, their activation mechanisms are different. These data suggest that both CyPA and CyPB are excellent targets for the treatment of HCV 1b, which shows the greatest resistance to interferon and ribavirin combination therapy. Copyright © 2012 Elsevier B.V. All rights reserved.

Identification and characterization of the host protein DNAJC14 as a broadly active flavivirus replication modulator.

PubMed

Yi, Zhigang; Sperzel, Lindsey; Nürnberger, Cindy; Bredenbeek, Peter J; Lubick, Kirk J; Best, Sonja M; Stoyanov, Cristina T; Law, Lok Man J; Yuan, Zhenghong; Rice, Charles M; MacDonald, Margaret R

2011-01-13

Viruses in the Flavivirus genus of the Flaviviridae family are arthropod-transmitted and contribute to staggering numbers of human infections and significant deaths annually across the globe. To identify cellular factors with antiviral activity against flaviviruses, we screened a cDNA library using an iterative approach. We identified a mammalian Hsp40 chaperone protein (DNAJC14) that when overexpressed was able to mediate protection from yellow fever virus (YFV)-induced cell death. Further studies revealed that DNAJC14 inhibits YFV at the step of viral RNA replication. Since replication of bovine viral diarrhea virus (BVDV), a member of the related Pestivirus genus, is also known to be modulated by DNAJC14, we tested the effect of this host factor on diverse Flaviviridae family members. Flaviviruses, including the pathogenic Asibi strain of YFV, Kunjin, and tick-borne Langat virus, as well as a Hepacivirus, hepatitis C virus (HCV), all were inhibited by overexpression of DNAJC14. Mutagenesis showed that both the J-domain and the C-terminal domain, which mediates self-interaction, are required for anti-YFV activity. We found that DNAJC14 does not block YFV nor HCV NS2-3 cleavage, and using non-inhibitory mutants demonstrate that DNAJC14 is recruited to YFV replication complexes. Immunofluorescence analysis demonstrated that endogenous DNAJC14 rearranges during infection and is found in replication complexes identified by dsRNA staining. Interestingly, silencing of endogenous DNAJC14 results in impaired YFV replication suggesting a requirement for DNAJC14 in YFV replication complex assembly. Finally, the antiviral activity of overexpressed DNAJC14 occurs in a time- and dose-dependent manner. DNAJC14 overexpression may disrupt the proper stoichiometry resulting in inhibition, which can be overcome upon restoration of the optimal ratios due to the accumulation of viral nonstructural proteins. Our findings, together with previously published work, suggest that the members of the Flaviviridae family have evolved in unique and important ways to interact with this host Hsp40 chaperone molecule.

RNA Polymerase Activity and Specific RNA Structure Are Required for Efficient HCV Replication in Cultured Cells

PubMed Central

Date, Tomoko; Akazawa, Daisuke; Tian, Xiao; Suzuki, Tetsuro; Kato, Takanobu; Tanaka, Yasuhito; Mizokami, Masashi; Wakita, Takaji; Toyoda, Tetsuya

2010-01-01

We have previously reported that the NS3 helicase (N3H) and NS5B-to-3′X (N5BX) regions are important for the efficient replication of hepatitis C virus (HCV) strain JFH-1 and viral production in HuH-7 cells. In the current study, we investigated the relationships between HCV genome replication, virus production, and the structure of N5BX. We found that the Q377R, A450S, S455N, R517K, and Y561F mutations in the NS5B region resulted in up-regulation of J6CF NS5B polymerase activity in vitro. However, the activation effects of these mutations on viral RNA replication and virus production with JFH-1 N3H appeared to differ. In the presence of the N3H region and 3′ untranslated region (UTR) of JFH-1, A450S, R517K, and Y561F together were sufficient to confer HCV genome replication activity and virus production ability to J6CF in cultured cells. Y561F was also involved in the kissing-loop interaction between SL3.2 in the NS5B region and SL2 in the 3′X region. We next analyzed the 3′ structure of HCV genome RNA. The shorter polyU/UC tracts of JFH-1 resulted in more efficient RNA replication than J6CF. Furthermore, 9458G in the JFH-1 variable region (VR) was responsible for RNA replication activity because of its RNA structures. In conclusion, N3H, high polymerase activity, enhanced kissing-loop interactions, and optimal viral RNA structure in the 3′UTR were required for J6CF replication in cultured cells. PMID:20442786

The Acyclic Retinoid Peretinoin Inhibits Hepatitis C Virus Replication and Infectious Virus Release in Vitro

NASA Astrophysics Data System (ADS)

Shimakami, Tetsuro; Honda, Masao; Shirasaki, Takayoshi; Takabatake, Riuta; Liu, Fanwei; Murai, Kazuhisa; Shiomoto, Takayuki; Funaki, Masaya; Yamane, Daisuke; Murakami, Seishi; Lemon, Stanley M.; Kaneko, Shuichi

2014-04-01

Clinical studies suggest that the oral acyclic retinoid Peretinoin may reduce the recurrence of hepatocellular carcinoma (HCC) following surgical ablation of primary tumours. Since hepatitis C virus (HCV) infection is a major cause of HCC, we assessed whether Peretinoin and other retinoids have any effect on HCV infection. For this purpose, we measured the effects of several retinoids on the replication of genotype 1a, 1b, and 2a HCV in vitro. Peretinoin inhibited RNA replication for all genotypes and showed the strongest antiviral effect among the retinoids tested. Furthermore, it reduced infectious virus release by 80-90% without affecting virus assembly. These effects could be due to reduced signalling from lipid droplets, triglyceride abundance, and the expression of mature sterol regulatory element-binding protein 1c and fatty acid synthase. These negative effects of Peretinoin on HCV infection may be beneficial in addition to its potential for HCC chemoprevention in HCV-infected patients.

Cis-acting RNA elements in the Hepatitis C virus RNA genome

PubMed Central

Sagan, Selena M.; Chahal, Jasmin; Sarnow, Peter

2017-01-01

Hepatitis C virus (HCV) infection is a rapidly increasing global health problem with an estimated 170 million people infected worldwide. HCV is a hepatotropic, positive-sense RNA virus of the family Flaviviridae. As a positive-sense RNA virus, the HCV genome itself must serve as a template for translation, replication and packaging. The viral RNA must therefore be a dynamic structure that is able to readily accommodate structural changes to expose different regions of the genome to viral and cellular proteins to carry out the HCV life cycle. The ∼9600 nucleotide viral genome contains a single long open reading frame flanked by 5′ and 3′ non-coding regions that contain cis-acting RNA elements important for viral translation, replication and stability. Additional cis-acting RNA elements have also been identified in the coding sequences as well as in the 3′ end of the negative-strand replicative intermediate. Herein, we provide an overview of the importance of these cis-acting RNA elements in the HCV life cycle. PMID:25576644

Essential role of cyclophilin A for hepatitis C virus replication and virus production and possible link to polyprotein cleavage kinetics.

PubMed

Kaul, Artur; Stauffer, Sarah; Berger, Carola; Pertel, Thomas; Schmitt, Jennifer; Kallis, Stephanie; Zayas, Margarita; Lopez, Margarita Zayas; Lohmann, Volker; Luban, Jeremy; Bartenschlager, Ralf

2009-08-01

Viruses are obligate intracellular parasites and therefore their replication completely depends on host cell factors. In case of the hepatitis C virus (HCV), a positive-strand RNA virus that in the majority of infections establishes persistence, cyclophilins are considered to play an important role in RNA replication. Subsequent to the observation that cyclosporines, known to sequester cyclophilins by direct binding, profoundly block HCV replication in cultured human hepatoma cells, conflicting results were obtained as to the particular cyclophilin (Cyp) required for viral RNA replication and the underlying possible mode of action. By using a set of cell lines with stable knock-down of CypA or CypB, we demonstrate in the present work that replication of subgenomic HCV replicons of different genotypes is reduced by CypA depletion up to 1,000-fold whereas knock-down of CypB had no effect. Inhibition of replication was rescued by over-expression of wild type CypA, but not by a mutant lacking isomerase activity. Replication of JFH1-derived full length genomes was even more sensitive to CypA depletion as compared to subgenomic replicons and virus production was completely blocked. These results argue that CypA may target an additional viral factor outside of the minimal replicase contributing to RNA amplification and assembly, presumably nonstructural protein 2. By selecting for resistance against the cyclosporine analogue DEBIO-025 that targets CypA in a dose-dependent manner, we identified two mutations (V2440A and V2440L) close to the cleavage site between nonstructural protein 5A and the RNA-dependent RNA polymerase in nonstructural protein 5B that slow down cleavage kinetics at this site and reduce CypA dependence of viral replication. Further amino acid substitutions at the same cleavage site accelerating processing increase CypA dependence. Our results thus identify an unexpected correlation between HCV polyprotein processing and CypA dependence of HCV replication.

STAT1 is essential for the inhibition of hepatitis C virus replication by interferon-λ but not by interferon-α.

PubMed

Yamauchi, Shota; Takeuchi, Kenji; Chihara, Kazuyasu; Honjoh, Chisato; Kato, Yuji; Yoshiki, Hatsumi; Hotta, Hak; Sada, Kiyonao

2016-12-08

Interferon-α (IFN-α) and IFN-λ are structurally distinct cytokines that bind to different receptors, but induce expression of similar sets of genes through Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathways. The difference between IFN-α and IFN-λ signaling remains poorly understood. Here, using the CRISPR/Cas9 system, we examine the role of STAT1 and STAT2 in the inhibition of hepatitis C virus (HCV) replication by IFN-α and IFN-λ. Treatment with IFN-α increases expression of IFN-stimulated genes (ISGs) such as double-stranded RNA-activated protein kinase (PKR) and decreases viral RNA and protein levels in HCV-infected Huh-7.5 human hepatoma cells. These responses are only partially attenuated by knockout of STAT1 but are abolished by knockout of STAT2. In contrast, the inhibition of HCV replication by IFN-λ is abolished by knockout of STAT1 or STAT2. Microarray analysis reveals that IFN-α but not IFN-λ can induce expression of the majority of ISGs in STAT1 knockout cells. These findings suggest that IFN-α can inhibit HCV replication through a STAT2-dependent but STAT1-independent pathway, whereas IFN-λ induces ISG expression and inhibits HCV replication exclusively through a STAT1- and STAT2-dependent pathway.

STAT1 is essential for the inhibition of hepatitis C virus replication by interferon-λ but not by interferon-α

PubMed Central

Yamauchi, Shota; Takeuchi, Kenji; Chihara, Kazuyasu; Honjoh, Chisato; Kato, Yuji; Yoshiki, Hatsumi; Hotta, Hak; Sada, Kiyonao

2016-01-01

Interferon-α (IFN-α) and IFN-λ are structurally distinct cytokines that bind to different receptors, but induce expression of similar sets of genes through Janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathways. The difference between IFN-α and IFN-λ signaling remains poorly understood. Here, using the CRISPR/Cas9 system, we examine the role of STAT1 and STAT2 in the inhibition of hepatitis C virus (HCV) replication by IFN-α and IFN-λ. Treatment with IFN-α increases expression of IFN-stimulated genes (ISGs) such as double-stranded RNA-activated protein kinase (PKR) and decreases viral RNA and protein levels in HCV-infected Huh-7.5 human hepatoma cells. These responses are only partially attenuated by knockout of STAT1 but are abolished by knockout of STAT2. In contrast, the inhibition of HCV replication by IFN-λ is abolished by knockout of STAT1 or STAT2. Microarray analysis reveals that IFN-α but not IFN-λ can induce expression of the majority of ISGs in STAT1 knockout cells. These findings suggest that IFN-α can inhibit HCV replication through a STAT2-dependent but STAT1-independent pathway, whereas IFN-λ induces ISG expression and inhibits HCV replication exclusively through a STAT1- and STAT2-dependent pathway. PMID:27929099

Identification of cellular and viral factors related to anti-hepatitis C virus activity of cyclophilin inhibitor.

PubMed

Goto, Kaku; Watashi, Koichi; Inoue, Daisuke; Hijikata, Makoto; Shimotohno, Kunitada

2009-10-01

We have so far reported that an immunosuppressant cyclosporin A (CsA), a well-known cyclophilin (CyP) inhibitor (CPI), strongly suppressed hepatitis C virus (HCV) replication in cell culture, and that CyPB was a cellular cofactor for viral replication. To further investigate antiviral mechanisms of CPI, we here developed cells carrying CsA-resistant HCV replicons, by culturing the HCV subgenomic replicon cells for 4 weeks in the presence of CsA with G418. Transfection of total RNA from the isolated CsA-resistant cells to naïve Huh7 cells conferred CsA resistance, suggesting that the replicon RNA itself was responsible for the resistant phenotype. Of the identified amino acid mutations, D320E in NS5A conferred the CsA resistance. The replicon carrying the D320E mutation was sensitive to interferon-alpha, but was resistant to CsA and other CPIs including NIM811 and sanglifehrin A. Knockdown of individual CyP subtypes revealed CyP40, in addition to CyPA and CyPB, contributed to viral replication, and CsA-resistant replicons acquired independence from CyPA for efficient replication. These data provide important evidence on the mechanisms underlying the regulation of HCV replication by CyP and for designing novel and specific anti-HCV strategies with CPIs.

HCV RNA traffic and association with NS5A in living cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiches, Guillaume N.; Eyre, Nicholas S.; Aloia, Amanda L.

The spatiotemporal dynamics of Hepatitis C Virus (HCV) RNA localisation are poorly understood. To address this we engineered HCV genomes harbouring MS2 bacteriophage RNA stem-loops within the 3′-untranslated region to allow tracking of HCV RNA via specific interaction with a MS2-Coat-mCherry fusion protein. Despite the impact of these insertions on viral fitness, live imaging revealed that replication of tagged-HCV genomes induced specific redistribution of the mCherry-tagged-MS2-Coat protein to motile and static foci. Further analysis showed that HCV RNA was associated with NS5A in both static and motile structures while a subset of motile NS5A structures was devoid of HCV RNA.more » Further investigation of viral RNA traffic with respect to lipid droplets (LDs) revealed HCV RNA-positive structures in close association with LDs. These studies provide new insights into the dynamics of HCV RNA traffic with NS5A and LDs and provide a platform for future investigations of HCV replication and assembly. - Highlights: • HCV can tolerate can bacteriophage MS2 stem-loop insertions within the 3′ UTR. • MS2 stem-loop containing HCV genomes allow for real-time imaging of HCV RNA. • HCV RNA is both static and motile and associates with NS5A and lipid droplets.« less

The history of hepatitis C virus (HCV): Basic research reveals unique features in phylogeny, evolution and the viral life cycle with new perspectives for epidemic control.

PubMed

Bukh, Jens

2016-10-01

The discovery of hepatitis C virus (HCV) in 1989 permitted basic research to unravel critical components of a complex life cycle for this important human pathogen. HCV is a highly divergent group of viruses classified in 7 major genotypes and a great number of subtypes, and circulating in infected individuals as a continuously evolving quasispecies destined to escape host immune responses and applied antivirals. Despite the inability to culture patient viruses directly in the laboratory, efforts to define the infectious genome of HCV resulted in development of experimental recombinant in vivo and in vitro systems, including replicons and infectious cultures in human hepatoma cell lines. And HCV has become a model virus defining new paradigms in virology, immunology and biology. For example, HCV research discovered that a virus could be completely dependent on microRNA for its replication since microRNA-122 is critical for the HCV life cycle. A number of other host molecules critical for HCV entry and replication have been identified. Thus, basic HCV research revealed important molecules for development of host targeting agents (HTA). The identification and characterization of HCV encoded proteins and their functional units contributed to the development of highly effective direct acting antivirals (DAA) against the NS3 protease, NS5A and the NS5B polymerase. In combination, these inhibitors have since 2014 permitted interferon-free therapy with cure rates above 90% among patients with chronic HCV infection; however, viral resistance represents a challenge. Worldwide control of HCV will most likely require the development of a prophylactic vaccine, and numerous candidates have been pursued. Research characterizing features critical for antibody-based virus neutralization and T cell based virus elimination from infected cells is essential for this effort. If the world community promotes an ambitious approach by applying current DAA broadly, continues to develop alternative viral- and host- targeted antivirals to combat resistant variants, and invests in the development of a vaccine, it would be possible to eradicate HCV. This would prevent about 500 thousand deaths annually. However, given the nature of HCV, the millions of new infections annually, a high chronicity rate, and with over 150 million individuals with chronic infection (which are frequently unidentified), this effort remains a major challenge for basic researchers, clinicians and communities. Copyright © 2016. Published by Elsevier B.V.

Internal Disequilibria and Phenotypic Diversification during Replication of Hepatitis C Virus in a Noncoevolving Cellular Environment

PubMed Central

Moreno, Elena; Gallego, Isabel; Gregori, Josep; Lucía-Sanz, Adriana; Soria, María Eugenia; Castro, Victoria; Beach, Nathan M.; Manrubia, Susanna; Quer, Josep; Esteban, Juan Ignacio; Rice, Charles M.; Gómez, Jordi; Gastaminza, Pablo

2017-01-01

ABSTRACT Viral quasispecies evolution upon long-term virus replication in a noncoevolving cellular environment raises relevant general issues, such as the attainment of population equilibrium, compliance with the molecular-clock hypothesis, or stability of the phenotypic profile. Here, we evaluate the adaptation, mutant spectrum dynamics, and phenotypic diversification of hepatitis C virus (HCV) in the course of 200 passages in human hepatoma cells in an experimental design that precluded coevolution of the cells with the virus. Adaptation to the cells was evidenced by increase in progeny production. The rate of accumulation of mutations in the genomic consensus sequence deviated slightly from linearity, and mutant spectrum analyses revealed a complex dynamic of mutational waves, which was sustained beyond passage 100. The virus underwent several phenotypic changes, some of which impacted the virus-host relationship, such as enhanced cell killing, a shift toward higher virion density, and increased shutoff of host cell protein synthesis. Fluctuations in progeny production and failure to reach population equilibrium at the genomic level suggest internal instabilities that anticipate an unpredictable HCV evolution in the complex liver environment. IMPORTANCE Long-term virus evolution in an unperturbed cellular environment can reveal features of virus evolution that cannot be explained by comparing natural viral isolates. In the present study, we investigate genetic and phenotypic changes that occur upon prolonged passage of hepatitis C virus (HCV) in human hepatoma cells in an experimental design in which host cell evolutionary change is prevented. Despite replication in a noncoevolving cellular environment, the virus exhibited internal population disequilibria that did not decline with increased adaptation to the host cells. The diversification of phenotypic traits suggests that disequilibria inherent to viral populations may provide a selective advantage to viruses that can be fully exploited in changing environments. PMID:28275194

HCV NS5A Up-Regulates COX-2 Expression via IL-8-Mediated Activation of the ERK/JNK MAPK Pathway

PubMed Central

Chen, Wei-Chun; Tseng, Chin-Kai; Chen, Yen-Hsu; Lin, Chun-Kuang; Hsu, Shih-hsien; Wang, Shen-Nien; Lee, Jin-Ching

2015-01-01

Chronic hepatitis C virus (HCV) infection leads to intrahepatic inflammation and liver cell injury, which are considered a risk factor for virus-associated hepatitis, cirrhosis, and hepatocellular carcinoma worldwide. Inflammatory cytokines are critical components of the immune system and influence cellular signaling, and genetic imbalances. In this study, we found that cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) were significantly induced by HCV infection and HCV NS5A expression, and induction of COX-2 correlated with HCV-induced IL-8 production. We also found that the ERK and JNK signaling pathways were involved in the regulation of IL-8-mediated COX-2 induction in response to HCV infection. Using a promoter-linked reporter assay, we identified that the C/EBP regulatory element within the COX-2 promoter was the dominant factor responsible for the induction of COX-2 by HCV. Silencing C/EBP attenuated HCV-induced COX-2 expression. Our results revealed that HCV-induced inflammation promotes viral replication, providing new insights into the involvement of IL-8-mediated COX-2 induction in HCV replication. PMID:26231035

[The specific enzyme inhibitors for potential therapeutic use].

PubMed

Bretner, Maria

2015-01-01

Therapy for hepatitis C virus (HCV) initially consisted on administering ribavirin - having a broad spectrum of action - and pegylated interferon, and was only effective in 40-50% of patients. Appropriate was to find effective inhibitors of viral replication e.g. by inhibition of a viral enzyme, NTPase/helicase required in the process of translation and RNA replication of the HCV. We developed methods of synthesis of many compounds belonging to different groups - derivatives of nucleosides, benzotriazole, benzimidazole, tropolone and epirubicine. Some of the derivatives inhibit HCV helicase activity at low concentrations and reduces replication of the viral RNA in subgenomic replicon system. In the process of HCV replication casein kinase CK2 plays an important role. It regulates the level of phosphorylation of HCV protein NS5A, which affects the production of infectious virions of HCV. Effective and selective inhibitors of kinase CK2 could be of use in the treatment of HCV in combination with other drugs. CK2 kinase phosphorylates approximately 300 proteins that affect the growth, differentiation, proliferation or apoptosis. Elevated CK2 kinase activity has been observed in several types of cancer and other diseases, therefore, inhibitors of this enzyme are potential therapeutic importance, particularly for anti-cancer treatment. Research carried out in collaboration with prof. Shugar led to the synthesis of one of the most selective inhibitors of this enzyme which is 4,5,6,7-tetrabromo-1H-benzotriazole, used for the study of the role of kinase CK2 in a number of metabolic processes in tumor cells.

Hepatitis C Virus Particle Assembly Involves Phosphorylation of NS5A by the c-Abl Tyrosine Kinase.

PubMed

Yamauchi, Shota; Takeuchi, Kenji; Chihara, Kazuyasu; Sun, Xuedong; Honjoh, Chisato; Yoshiki, Hatsumi; Hotta, Hak; Sada, Kiyonao

2015-09-04

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is thought to regulate the replication of viral RNA and the assembly of virus particles in a serine/threonine phosphorylation-dependent manner. However, the host kinases that phosphorylate NS5A have not been fully identified. Here, we show that HCV particle assembly involves the phosphorylation of NS5A by the c-Abl tyrosine kinase. Pharmacological inhibition or knockdown of c-Abl reduces the production of infectious HCV (J6/JFH1) particles in Huh-7.5 cells without markedly affecting viral RNA translation and replication. NS5A is tyrosine-phosphorylated in HCV-infected cells, and this phosphorylation is also reduced by the knockdown of c-Abl. Mutational analysis reveals that NS5A tyrosine phosphorylation is dependent, at least in part, on Tyr(330) (Tyr(2306) in polyprotein numbering). Mutation of this residue to phenylalanine reduces the production of infectious HCV particles but does not affect the replication of the JFH1 subgenomic replicon. These findings suggest that c-Abl promotes HCV particle assembly by phosphorylating NS5A at Tyr(330). © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Cyclophilin B stimulates RNA synthesis by the HCV RNA dependent RNA polymerase.

PubMed

Heck, Julie A; Meng, Xiao; Frick, David N

2009-04-01

Cyclophilins are cellular peptidyl isomerases that have been implicated in regulating hepatitis C virus (HCV) replication. Cyclophilin B (CypB) is a target of cyclosporin A (CsA), an immunosuppressive drug recently shown to suppress HCV replication in cell culture. Watashi et al. recently demonstrated that CypB is important for efficient HCV replication, and proposed that it mediates the anti-HCV effects of CsA through an interaction with NS5B [Watashi K, Ishii N, Hijikata M, Inoue D, Murata T, Miyanari Y, et al. Cyclophilin B is a functional regulator of hepatitis C virus RNA polymerase. Mol Cell 2005;19:111-22]. We examined the effects of purified CypB proteins on the enzymatic activity of NS5B. Recombinant CypB purified from insect cells directly stimulated NS5B-catalyzed RNA synthesis. CypB increased RNA synthesis by NS5B derived from genotype 1a, 1b, and 2a HCV strains. Stimulation appears to arise from an increase in productive RNA binding. NS5B residue Pro540, a previously proposed target of CypB peptidyl-prolyl isomerase activity, is not required for stimulation of RNA synthesis.

Mapping of Functional Domains of the Lipid Kinase Phosphatidylinositol 4-Kinase Type III Alpha Involved in Enzymatic Activity and Hepatitis C Virus Replication

PubMed Central

Harak, Christian; Radujkovic, Danijela; Taveneau, Cyntia; Reiss, Simon; Klein, Rahel; Bressanelli, Stéphane

2014-01-01

ABSTRACT The lipid kinase phosphatidylinositol 4-kinase III alpha (PI4KIIIα) is an endoplasmic reticulum (ER)-resident enzyme that synthesizes phosphatidylinositol 4-phosphate (PI4P). PI4KIIIα is an essential host factor for hepatitis C virus (HCV) replication. Interaction with HCV nonstructural protein 5A (NS5A) leads to kinase activation and accumulation of PI4P at intracellular membranes. In this study, we investigated the structural requirements of PI4KIIIα in HCV replication and enzymatic activity. Therefore, we analyzed PI4KIIIα mutants for subcellular localization, reconstitution of HCV replication in PI4KIIIα knockdown cell lines, PI4P induction in HCV-positive cells, and lipid kinase activity in vitro. All mutants still interacted with NS5A and localized in a manner similar to that of the full-length enzyme, suggesting multiple regions of PI4KIIIα are involved in NS5A interaction and subcellular localization. Interestingly, the N-terminal 1,152 amino acids were dispensable for HCV replication, PI4P induction, and enzymatic function, whereas further N-terminal or C-terminal deletions were deleterious, thereby defining the minimal PI4KIIIα core enzyme at a size of ca. 108 kDa. Additional deletion of predicted functional motifs within the C-terminal half of PI4KIIIα also were detrimental for enzymatic activity and for the ability of PI4KIIIα to rescue HCV replication, with the exception of a proposed nuclear localization signal, suggesting that the entire C-terminal half of PI4KIIIα is involved in the formation of a minimal enzymatic core. This view was supported by structural modeling of the PI4KIIIα C terminus, suggesting a catalytic center formed by an N- and C-terminal lobe and an armadillo-fold motif, which is preceded by three distinct alpha-helical domains probably involved in regulation of enzymatic activity. IMPORTANCE The lipid kinase PI4KIIIα is of central importance for cellular phosphatidylinositol metabolism and is a key host cell factor of hepatitis C virus replication. However, little is known so far about the structure of this 240-kDa protein and the functional importance of specific subdomains regarding lipid kinase activity and viral replication. This work focuses on the phenotypic analysis of distinct PI4KIIIα mutants in different biochemical and cell-based assays and develops a structural model of the C-terminal enzymatic core. The results shed light on the structural and functional requirements of enzymatic activity and the determinants required for HCV replication. PMID:24920820

HBV Bypasses the Innate Immune Response and Does Not Protect HCV From Antiviral Activity of Interferon.

PubMed

Mutz, Pascal; Metz, Philippe; Lempp, Florian A; Bender, Silke; Qu, Bingqian; Schöneweis, Katrin; Seitz, Stefan; Tu, Thomas; Restuccia, Agnese; Frankish, Jamie; Dächert, Christopher; Schusser, Benjamin; Koschny, Ronald; Polychronidis, Georgios; Schemmer, Peter; Hoffmann, Katrin; Baumert, Thomas F; Binder, Marco; Urban, Stephan; Bartenschlager, Ralf

2018-05-01

Hepatitis C virus (HCV) infection is sensitive to interferon (IFN)-based therapy, whereas hepatitis B virus (HBV) infection is not. It is unclear whether HBV escapes detection by the IFN-mediated immune response or actively suppresses it. Moreover, little is known on how HBV and HCV influence each other in coinfected cells. We investigated interactions between HBV and the IFN-mediated immune response using HepaRG cells and primary human hepatocytes (PHHs). We analyzed the effects of HBV on HCV replication, and vice versa, at the single-cell level. PHHs were isolated from liver resection tissues from HBV-, HCV-, and human immunodeficiency virus-negative patients. Differentiated HepaRG cells overexpressing the HBV receptor sodium taurocholate cotransporting polypeptide (dHepaRGNTCP) and PHHs were infected with HBV. Huh7.5 cells were transfected with circular HBV DNA genomes resembling viral covalently closed circular DNA (cccDNA), and subsequently infected with HCV; this served as a model of HBV and HCV coinfection. Cells were incubated with IFN inducers, or IFNs, and antiviral response and viral replication were analyzed by immune fluorescence, reverse-transcription quantitative polymerase chain reaction, enzyme-linked immunosorbent assays, and flow cytometry. HBV infection of dHepaRGNTCP cells and PHHs neither activated nor inhibited signaling via pattern recognition receptors. Incubation of dHepaRGNTCP cells and PHHs with IFN had little effect on HBV replication or levels of cccDNA. HBV infection of these cells did not inhibit JAK-STAT signaling or up-regulation of IFN-stimulated genes. In coinfected cells, HBV did not prevent IFN-induced suppression of HCV replication. In dHepaRGNTCP cells and PHHs, HBV evades the induction of IFN and IFN-induced antiviral effects. HBV infection does not rescue HCV from the IFN-mediated response. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Modelling hepatitis C therapy—predicting effects of treatment

PubMed Central

Perelson, Alan S.; Guedj, Jeremie

2015-01-01

Mathematically modelling HCV RNA changes measured in patients who receive antiviral therapy has yielded many insights into the pathogenesis and effects of treatment on the virus. By determining how rapidly HCV is cleared when viral replication is interrupted by a therapy, one can deduce how rapidly the virus is produced in patients before treatment. This knowledge, coupled with estimates of the HCV mutation rate, enables one to estimate the frequency with which drug resistant variants arise. Modelling HCV also permits the deduction of antiviral agent effectiveness at blocking HCV replication from the magnitude of the initial viral decline. One can also estimate the lifespan of an HCV infected cell from the slope of the subsequent viral decline and, determine the duration of therapy needed to cure infection. Our understanding of HCV RNA decline under IFN-based therapies needs to be revised in order to understand the HCV RNA decline kinetics seen when using direct-acting antiviral agents (DAAs). In this Review, we also discuss the unresolved issues involving understanding therapies with combinations of DAAs, such as whether a sustained virological response necessarily involves elimination of all infected cells PMID:26122475

Anti-HCV effect of Lentinula edodes mycelia solid culture extracts and low-molecular-weight lignin.

PubMed

Matsuhisa, Koji; Yamane, Seiji; Okamoto, Toru; Watari, Akihiro; Kondoh, Masuo; Matsuura, Yoshiharu; Yagi, Kiyohito

2015-06-19

Lentinula edodes mycelia solid culture extract (MSCE) contains several bioactive molecules, including some polyphenolic compounds, which exert immunomodulatory, antitumor, and hepatoprotective effects. In this study, we examined the anti-hepatitis C virus (HCV) activity of MSCE and low-molecular-weight lignin (LM-lignin), which is the active component responsible for the hepatoprotective effect of MSCE. Both MSCE and LM-lignin inhibited the entry of two HCV pseudovirus (HCVpv) types into Huh7.5.1 cells. LM-lignin inhibited HCVpv entry at a lower concentration than MSCE and inhibited the entry of HCV particles in cell culture (HCVcc). MSCE also inhibited HCV subgenome replication. LM-lignin had no effect on HCV replication, suggesting that MSCE contains additional active substances. We demonstrate here for the first time the anti-HCV effects of plant-derived LM-lignin and MSCE. The hepatoprotective effect of LM-lignin suggests that lignin derivatives, which can be produced in abundance from existing plant resources, may be effective in the treatment of HCV-related diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

IFN-λ Inhibits MiR-122 Transcription through a Stat3-HNF4α Inflammatory Feedback Loop in an IFN-α Resistant HCV Cell Culture System

PubMed Central

Aboulnasr, Fatma; Hazari, Sidhartha; Nayak, Satyam; Chandra, Partha K.; Panigrahi, Rajesh; Ferraris, Pauline; Chava, Srinivas; Kurt, Ramazan; Song, Kyongsub; Dash, Asha; Balart, Luis A.; Garry, Robert F.; Wu, Tong; Dash, Srikanta

2015-01-01

Background HCV replication in persistently infected cell culture remains resistant to IFN-α/RBV combination treatment, whereas IFN-λ1 induces viral clearance. The antiviral mechanisms by which IFN-λ1 induces sustained HCV clearance have not been determined. Aim To investigate the mechanisms by which IFN-λ clears HCV replication in an HCV cell culture model. Methods IFN-α sensitive (S3-GFP) and resistant (R4-GFP) cells were treated with equivalent concentrations of either IFN-α or IFN-λ. The relative antiviral effects of IFN-α and IFN-λ1 were compared by measuring the HCV replication, quantification of HCV-GFP expression by flow cytometry, and viral RNA levels by real time RT-PCR. Activation of Jak-Stat signaling, interferon stimulated gene (ISG) expression, and miRNA-122 transcription in S3-GFP and R4-GFP cells were examined. Results We have shown that IFN-λ1 induces HCV clearance in IFN-α resistant and sensitive replicon cell lines in a dose dependent manner through Jak-Stat signaling, and induces STAT 1 and STAT 2 activation, ISRE-luciferase promoter activation and ISG expression. Stat 3 activation is also involved in IFN-λ1 induced antiviral activity in HCV cell culture. IFN-λ1 induced Stat 3 phosphorylation reduces the expression of hepatocyte nuclear factor 4 alpha (HNF4α) through miR-24 in R4-GFP cells. Reduced expression of HNF4α is associated with decreased expression of miR-122 resulting in an anti-HCV effect. Northern blot analysis confirms that IFN-λ1 reduces miR-122 levels in R4-GFP cells. Our results indicate that IFN-λ1 activates the Stat 3-HNF4α feedback inflammatory loop to inhibit miR-122 transcription in HCV cell culture. Conclusions In addition to the classical Jak–Stat antiviral signaling pathway, IFN-λ1 inhibits HCV replication through the suppression of miRNA-122 transcription via an inflammatory Stat 3–HNF4α feedback loop. Inflammatory feedback circuits activated by IFNs during chronic inflammation expose non-responders to the risk of hepatocellular carcinoma. PMID:26657215

Natural compounds isolated from Brazilian plants are potent inhibitors of hepatitis C virus replication in vitro.

PubMed

Jardim, A C G; Igloi, Z; Shimizu, J F; Santos, V A F F M; Felippe, L G; Mazzeu, B F; Amako, Y; Furlan, M; Harris, M; Rahal, P

2015-03-01

Compounds extracted from plants can provide an alternative approach to new therapies. They present characteristics such as high chemical diversity, lower cost of production and milder or inexistent side effects compared with conventional treatment. The Brazilian flora represents a vast, largely untapped, resource of potential antiviral compounds. In this study, we investigate the antiviral effects of a panel of natural compounds isolated from Brazilian plants species on hepatitis C virus (HCV) genome replication. To do this we used firefly luciferase-based HCV sub-genomic replicons of genotypes 2a (JFH-1), 1b and 3a and the compounds were assessed for their effects on both HCV replication and cellular toxicity. Initial screening of compounds was performed using the maximum non-toxic concentration and 4 compounds that exhibited a useful therapeutic index (favourable ratio of cytotoxicity to antiviral potency) were selected for extra analysis. The compounds APS (EC50=2.3μM), a natural alkaloid isolated from Maytrenus ilicifolia, and the lignans 3(∗)43 (EC50=4.0μM), 3(∗)20 (EC50=8.2μM) and 5(∗)362 (EC50=38.9μM) from Peperomia blanda dramatically inhibited HCV replication as judged by reductions in luciferase activity and HCV protein expression in both the subgenomic and infectious systems. We further show that these compounds are active against a daclatasvir resistance mutant subgenomic replicon. Consistent with inhibition of genome replication, production of infectious JFH-1 virus was significantly reduced by all 4 compounds. These data are the first description of Brazilian natural compounds possessing anti-HCV activity and further analyses are being performed in order to investigate the mode of action of those compounds. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Cellular DEAD-box RNA helicase DDX6 modulates interaction of miR-122 with the 5' untranslated region of hepatitis C virus RNA.

PubMed

Biegel, Jason M; Henderson, Eric; Cox, Erica M; Bonenfant, Gaston; Netzband, Rachel; Kahn, Samantha; Eager, Rachel; Pager, Cara T

2017-07-01

Hepatitis C virus (HCV) subverts the cellular DEAD-box RNA helicase DDX6 to promote virus infection. Using polysome gradient analysis and the subgenomic HCV Renilla reporter replicon genome, we determined that DDX6 does not affect HCV translation. Rather expression of the subgenomic HCV Renilla luciferase reporter at late times, as well as labeling of newly synthesized viral RNA with 4-thiouridine showed that DDX6 modulates replication. Because DDX6 is an effector protein of the microRNA pathway, we also investigated its role in miR-122-directed HCV gene expression. Similar to sequestering miR-122, depletion of DDX6 modulated HCV RNA stability. Interestingly, miR-122-HCV RNA interaction assays with mutant HCV genomes sites and compensatory exogenous miR-122 showed that DDX6 affects the function of miR-122 at one particular binding site. We propose that DDX6 facilitates the miR-122 interaction with HCV 5' UTR, which is necessary for stabilizing the viral genome and the switch between translation and replication. Copyright © 2017 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perelson, Alan S.; Guedj, Jeremie

Mathematically modelling changes in HCV RNA levels measured in patients who receive antiviral therapy has yielded many insights into the pathogenesis and effects of treatment on the virus. By determining how rapidly HCV is cleared when viral replication is interrupted by a therapy, one can deduce how rapidly the virus is produced in patients before treatment. This knowledge, coupled with estimates of the HCV mutation rate, enables one to estimate the frequency with which drug resistant variants arise. Modelling HCV also permits the deduction of the effectiveness of an antiviral agent at blocking HCV replication from the magnitude of themore » initial viral decline. One can also estimate the lifespan of an HCV-infected cell from the slope of the subsequent viral decline and determine the duration of therapy needed to cure infection. The original understanding of HCV RNA decline under interferon-based therapies obtained by modelling needed to be revised in order to interpret the HCV RNA decline kinetics seen when using direct-acting antiviral agents (DAAs). In addition, there also exist unresolved issues involving understanding therapies with combinations of DAAs, such as the presence of detectable HCV RNA at the end of therapy in patients who nonetheless have a sustained virologic response.« less

Hepatitis C virus depends on E-cadherin as an entry factor and regulates its expression in epithelial-to-mesenchymal transition.

PubMed

Li, Qisheng; Sodroski, Catherine; Lowey, Brianna; Schweitzer, Cameron J; Cha, Helen; Zhang, Fang; Liang, T Jake

2016-07-05

Hepatitis C virus (HCV) enters the host cell through interactions with a cascade of cellular factors. Although significant progress has been made in understanding HCV entry, the precise mechanisms by which HCV exploits the receptor complex and host machinery to enter the cell remain unclear. This intricate process of viral entry likely depends on additional yet-to-be-defined cellular molecules. Recently, by applying integrative functional genomics approaches, we identified and interrogated distinct sets of host dependencies in the complete HCV life cycle. Viral entry assays using HCV pseudoparticles (HCVpps) of various genotypes uncovered multiple previously unappreciated host factors, including E-cadherin, that mediate HCV entry. E-cadherin silencing significantly inhibited HCV infection in Huh7.5.1 cells, HepG2/miR122/CD81 cells, and primary human hepatocytes at a postbinding entry step. Knockdown of E-cadherin, however, had no effect on HCV RNA replication or internal ribosomal entry site (IRES)-mediated translation. In addition, an E-cadherin monoclonal antibody effectively blocked HCV entry and infection in hepatocytes. Mechanistic studies demonstrated that E-cadherin is closely associated with claudin-1 (CLDN1) and occludin (OCLN) on the cell membrane. Depletion of E-cadherin drastically diminished the cell-surface distribution of these two tight junction proteins in various hepatic cell lines, indicating that E-cadherin plays an important regulatory role in CLDN1/OCLN localization on the cell surface. Furthermore, loss of E-cadherin expression in hepatocytes is associated with HCV-induced epithelial-to-mesenchymal transition (EMT), providing an important link between HCV infection and liver cancer. Our data indicate that a dynamic interplay among E-cadherin, tight junctions, and EMT exists and mediates an important function in HCV entry.

New insights into HCV replication in original cells from Aedes mosquitoes.

PubMed

Fallecker, Catherine; Caporossi, Alban; Rechoum, Yassine; Garzoni, Frederic; Larrat, Sylvie; François, Olivier; Fender, Pascal; Morand, Patrice; Berger, Imre; Petit, Marie-Anne; Drouet, Emmanuel

2017-08-22

The existing literature about HCV association with, and replication in mosquitoes is extremely poor. To fill this gap, we performed cellular investigations aimed at exploring (i) the capacity of HCV E1E2 glycoproteins to bind on Aedes mosquito cells and (ii) the ability of HCV serum particles (HCVsp) to replicate in these cell lines. First, we used purified E1E2 expressing baculovirus-derived HCV pseudo particles (bacHCVpp) so we could investigate their association with mosquito cell lines from Aedes aegypti (Aag-2) and Aedes albopictus (C6/36). We initiated a series of infections of both mosquito cells (Ae aegypti and Ae albopictus) with the HCVsp (Lat strain - genotype 3) and we observed the evolution dynamics of viral populations within cells over the course of infection via next-generation sequencing (NGS) experiments. Our binding assays revealed bacHCVpp an association with the mosquito cells, at comparable levels obtained with human hepatocytes (HepaRG cells) used as a control. In our infection experiments, the HCV RNA (+) were detectable by RT-PCR in the cells between 21 and 28 days post-infection (p.i.). In human hepatocytes HepaRG and Ae aegypti insect cells, NGS experiments revealed an increase of global viral diversity with a selection for a quasi-species, suggesting a structuration of the population with elimination of deleterious mutations. The evolutionary pattern in Ae albopictus insect cells is different (stability of viral diversity and polymorphism). These results demonstrate for the first time that natural HCV could really replicate within Aedes mosquitoes, a discovery which may have major consequences for public health as well as in vaccine development.

Computational Study on the Inhibitor Binding Mode and Allosteric Regulation Mechanism in Hepatitis C Virus NS3/4A Protein

PubMed Central

Xue, Weiwei; Yang, Ying; Wang, Xiaoting; Liu, Huanxiang; Yao, Xiaojun

2014-01-01

HCV NS3/4A protein is an attractive therapeutic target responsible for harboring serine protease and RNA helicase activities during the viral replication. Small molecules binding at the interface between the protease and helicase domains can stabilize the closed conformation of the protein and thus block the catalytic function of HCV NS3/4A protein via an allosteric regulation mechanism. But the detailed mechanism remains elusive. Here, we aimed to provide some insight into the inhibitor binding mode and allosteric regulation mechanism of HCV NS3/4A protein by using computational methods. Four simulation systems were investigated. They include: apo state of HCV NS3/4A protein, HCV NS3/4A protein in complex with an allosteric inhibitor and the truncated form of the above two systems. The molecular dynamics simulation results indicate HCV NS3/4A protein in complex with the allosteric inhibitor 4VA adopts a closed conformation (inactive state), while the truncated apo protein adopts an open conformation (active state). Further residue interaction network analysis suggests the communication of the domain-domain interface play an important role in the transition from closed to open conformation of HCV NS3/4A protein. However, the inhibitor stabilizes the closed conformation through interaction with several key residues from both the protease and helicase domains, including His57, Asp79, Asp81, Asp168, Met485, Cys525 and Asp527, which blocks the information communication between the functional domains interface. Finally, a dynamic model about the allosteric regulation and conformational changes of HCV NS3/4A protein was proposed and could provide fundamental insights into the allosteric mechanism of HCV NS3/4A protein function regulation and design of new potent inhibitors. PMID:24586263

The HCV Non-Nucleoside Inhibitor Tegobuvir Utilizes a Novel Mechanism of Action to Inhibit NS5B Polymerase Function

PubMed Central

Hebner, Christy M.; Han, Bin; Brendza, Katherine M.; Nash, Michelle; Sulfab, Maisoun; Tian, Yang; Hung, Magdeleine; Fung, Wanchi; Vivian, Randall W.; Trenkle, James; Taylor, James; Bjornson, Kyla; Bondy, Steven; Liu, Xiaohong; Link, John; Neyts, Johan; Sakowicz, Roman; Zhong, Weidong; Tang, Hengli; Schmitz, Uli

2012-01-01

Tegobuvir (TGV) is a novel non-nucleoside inhibitor (NNI) of HCV RNA replication with demonstrated antiviral activity in patients with genotype 1 chronic HCV infection. The mechanism of action of TGV has not been clearly defined despite the identification of resistance mutations mapping to the NS5B polymerase region. TGV does not inhibit NS5B enzymatic activity in biochemical assays in vitro, suggesting a more complex antiviral mechanism with cellular components. Here, we demonstrate that TGV exerts anti-HCV activity utilizing a unique chemical activation and subsequent direct interaction with the NS5B protein. Treatment of HCV subgenomic replicon cells with TGV results in a modified form of NS5B with a distinctly altered mobility on a SDS-PAGE gel. Further analysis reveals that the aberrantly migrating NS5B species contains the inhibitor molecule. Formation of this complex does not require the presence of any other HCV proteins. The intensity of the aberrantly migrating NS5B species is strongly dependent on cellular glutathione levels as well as CYP 1A activity. Furthermore analysis of NS5B protein purified from a heterologous expression system treated with TGV by mass spectrometry suggests that TGV undergoes a CYP- mediated intracellular activation step and the resulting metabolite, after forming a glutathione conjugate, directly and specifically interacts with NS5B. Taken together, these data demonstrate that upon metabolic activation TGV is a specific, covalent inhibitor of the HCV NS5B polymerase and is mechanistically distinct from other classes of the non-nucleoside inhibitors (NNI) of the viral polymerase. PMID:22720059

Progress on New Hepatitis C Virus Targets: NS2 and NS5A

NASA Astrophysics Data System (ADS)

Marcotrigiano, Joseph

Hepatitis C virus (HCV) is a major global health problem, affecting about 170 million people worldwide. Chronic infection can lead to cirrhosis and liver cancer. The replication machine of HCV is a multi-subunit membrane associated complex, consisting of nonstructural proteins (NS2-5B), which replicate the viral RNA genome. The structures of NS5A and NS2 were recently determined. NS5A is an essential replicase component that also modulates numerous cellular processes ranging from innate immunity to cell growth and survival. The structure reveals a novel protein fold, a new zinc coordination motif, a disulfide bond and a dimer interface. Analysis of molecular surfaces suggests the location of the membrane interaction surface of NS5A, as well as hypothetical protein and RNA binding sites. NS2 is one of two virally encoded proteases that are required for processing the viral polyprotein into the mature nonstructural proteins. NS2 is a dimeric cysteine protease with two composite active sites. For each active site, the catalytic histidine and glutamate residues are contributed by one monomer and the nucleophilic cysteine by the other. The C-terminal residues remain coordinated in the two active sites, predicting an inactive post-cleavage form. The structure also reveals possible sites of membrane interaction, a rare cis-proline residue, and highly conserved dimer contacts. The novel features of both structures have changed the current view of HCV polyprotein replication and present new opportunities for antiviral drug design.

Modelling hepatitis C therapy—predicting effects of treatment

DOE PAGES

Perelson, Alan S.; Guedj, Jeremie

2015-06-30

Mathematically modelling changes in HCV RNA levels measured in patients who receive antiviral therapy has yielded many insights into the pathogenesis and effects of treatment on the virus. By determining how rapidly HCV is cleared when viral replication is interrupted by a therapy, one can deduce how rapidly the virus is produced in patients before treatment. This knowledge, coupled with estimates of the HCV mutation rate, enables one to estimate the frequency with which drug resistant variants arise. Modelling HCV also permits the deduction of the effectiveness of an antiviral agent at blocking HCV replication from the magnitude of themore » initial viral decline. One can also estimate the lifespan of an HCV-infected cell from the slope of the subsequent viral decline and determine the duration of therapy needed to cure infection. The original understanding of HCV RNA decline under interferon-based therapies obtained by modelling needed to be revised in order to interpret the HCV RNA decline kinetics seen when using direct-acting antiviral agents (DAAs). In addition, there also exist unresolved issues involving understanding therapies with combinations of DAAs, such as the presence of detectable HCV RNA at the end of therapy in patients who nonetheless have a sustained virologic response.« less

Identification and Characterization of the Host Protein DNAJC14 as a Broadly Active Flavivirus Replication Modulator

PubMed Central

Yi, Zhigang; Sperzel, Lindsey; Nürnberger, Cindy; Bredenbeek, Peter J.; Lubick, Kirk J.; Best, Sonja M.; Stoyanov, Cristina T.; Law, Lok Man J.; Yuan, Zhenghong; Rice, Charles M.; MacDonald, Margaret R.

2011-01-01

Viruses in the Flavivirus genus of the Flaviviridae family are arthropod-transmitted and contribute to staggering numbers of human infections and significant deaths annually across the globe. To identify cellular factors with antiviral activity against flaviviruses, we screened a cDNA library using an iterative approach. We identified a mammalian Hsp40 chaperone protein (DNAJC14) that when overexpressed was able to mediate protection from yellow fever virus (YFV)-induced cell death. Further studies revealed that DNAJC14 inhibits YFV at the step of viral RNA replication. Since replication of bovine viral diarrhea virus (BVDV), a member of the related Pestivirus genus, is also known to be modulated by DNAJC14, we tested the effect of this host factor on diverse Flaviviridae family members. Flaviviruses, including the pathogenic Asibi strain of YFV, Kunjin, and tick-borne Langat virus, as well as a Hepacivirus, hepatitis C virus (HCV), all were inhibited by overexpression of DNAJC14. Mutagenesis showed that both the J-domain and the C-terminal domain, which mediates self-interaction, are required for anti-YFV activity. We found that DNAJC14 does not block YFV nor HCV NS2-3 cleavage, and using non-inhibitory mutants demonstrate that DNAJC14 is recruited to YFV replication complexes. Immunofluorescence analysis demonstrated that endogenous DNAJC14 rearranges during infection and is found in replication complexes identified by dsRNA staining. Interestingly, silencing of endogenous DNAJC14 results in impaired YFV replication suggesting a requirement for DNAJC14 in YFV replication complex assembly. Finally, the antiviral activity of overexpressed DNAJC14 occurs in a time- and dose-dependent manner. DNAJC14 overexpression may disrupt the proper stoichiometry resulting in inhibition, which can be overcome upon restoration of the optimal ratios due to the accumulation of viral nonstructural proteins. Our findings, together with previously published work, suggest that the members of the Flaviviridae family have evolved in unique and important ways to interact with this host Hsp40 chaperone molecule. PMID:21249176

Cell culture-adaptive mutations of NS5A affect replication of hepatitis C virus differentially depending on the viral genotypes.

PubMed

Chung, Aeri; Jin, Bora; Han, Kwang-Hyub; Ahn, Sang Hoon; Kim, Seungtaek

2017-01-01

Most of HCV RNAs require cell culture-adaptive mutations for efficient replication in cell culture and a number of such mutations have been described including a well-known S2204I substitution mutation in NS5A protein. In contrast, the replication of genotype 2a JFH1 RNA in cell culture does not require any cell culture-adaptive mutation. Rather, the presence of S2204I mutation impaired the JFH1 RNA replication. In this study, we examined the effect of reversions and substitutions of NS5A cell culture-adaptive mutations on virus replication in different genotypic backgrounds after either placing genotype 1a NS5A in the genotype 2a JFH1 or vice versa. The results from this investigation suggest that the S2204I mutation affects HCV RNA replication differentially depending on the viral genotypes but that the effect was not simply explained by the genotypic background. Perhaps, the effect of the S2204I mutation on HCV replication reflects both intra- and intergenic interactions of NS5A protein. J. Med. Virol. 89:146-152, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Host-derived apolipoproteins play comparable roles with viral secretory proteins Erns and NS1 in the infectious particle formation of Flaviviridae

PubMed Central

Ono, Chikako; Shiokawa, Mai; Mori, Hiroyuki; Uemura, Kentaro; Yamamoto, Satomi; Okamoto, Toru; Suzuki, Ryosuke; Yoshii, Kentaro; Kurosu, Takeshi; Igarashi, Manabu; Aoki, Hiroshi; Sakoda, Yoshihiro

2017-01-01

Amphipathic α-helices of exchangeable apolipoproteins have shown to play crucial roles in the formation of infectious hepatitis C virus (HCV) particles through the interaction with viral particles. Among the Flaviviridae members, pestivirus and flavivirus possess a viral structural protein Erns or a non-structural protein 1 (NS1) as secretory glycoproteins, respectively, while Hepacivirus including HCV has no secretory glycoprotein. In case of pestivirus replication, the C-terminal long amphipathic α-helices of Erns are important for anchoring to viral membrane. Here we show that host-derived apolipoproteins play functional roles similar to those of virally encoded Erns and NS1 in the formation of infectious particles. We examined whether Erns and NS1 could compensate for the role of apolipoproteins in particle formation of HCV in apolipoprotein B (ApoB) and ApoE double-knockout Huh7 (BE-KO), and non-hepatic 293T cells. We found that exogenous expression of either Erns or NS1 rescued infectious particle formation of HCV in the BE-KO and 293T cells. In addition, expression of apolipoproteins or NS1 partially rescued the production of infectious pestivirus particles in cells upon electroporation with an Erns-deleted non-infectious RNA. As with exchangeable apolipoproteins, the C-terminal amphipathic α-helices of Erns play the functional roles in the formation of infectious HCV or pestivirus particles. These results strongly suggest that the host- and virus-derived secretory glycoproteins have overlapping roles in the viral life cycle of Flaviviridae, especially in the maturation of infectious particles, while Erns and NS1 also participate in replication complex formation and viral entry, respectively. Considering the abundant hepatic expression and liver-specific propagation of these apolipoproteins, HCV might have evolved to utilize them in the formation of infectious particles through deletion of a secretory viral glycoprotein gene. PMID:28644867

Productive Homologous and Non-homologous Recombination of Hepatitis C Virus in Cell Culture

PubMed Central

Li, Yi-Ping; Mikkelsen, Lotte S.; Gottwein, Judith M.; Bukh, Jens

2013-01-01

Genetic recombination is an important mechanism for increasing diversity of RNA viruses, and constitutes a viral escape mechanism to host immune responses and to treatment with antiviral compounds. Although rare, epidemiologically important hepatitis C virus (HCV) recombinants have been reported. In addition, recombination is an important regulatory mechanism of cytopathogenicity for the related pestiviruses. Here we describe recombination of HCV RNA in cell culture leading to production of infectious virus. Initially, hepatoma cells were co-transfected with a replicating JFH1ΔE1E2 genome (genotype 2a) lacking functional envelope genes and strain J6 (2a), which has functional envelope genes but does not replicate in culture. After an initial decrease in the number of HCV positive cells, infection spread after 13–36 days. Sequencing of recovered viruses revealed non-homologous recombinants with J6 sequence from the 5′ end to the NS2–NS3 region followed by JFH1 sequence from Core to the 3′ end. These recombinants carried duplicated sequence of up to 2400 nucleotides. HCV replication was not required for recombination, as recombinants were observed in most experiments even when two replication incompetent genomes were co-transfected. Reverse genetic studies verified the viability of representative recombinants. After serial passage, subsequent recombination events reducing or eliminating the duplicated region were observed for some but not all recombinants. Furthermore, we found that inter-genotypic recombination could occur, but at a lower frequency than intra-genotypic recombination. Productive recombination of attenuated HCV genomes depended on expression of all HCV proteins and tolerated duplicated sequence. In general, no strong site specificity was observed. Non-homologous recombination was observed in most cases, while few homologous events were identified. A better understanding of HCV recombination could help identification of natural recombinants and thereby lead to improved therapy. Our findings suggest mechanisms for occurrence of recombinants observed in patients. PMID:23555245

Relationship between Hepatitis C Virus Infection and Iron Overload.

PubMed

Zou, Dong-Mei; Sun, Wan-Ling

2017-04-05

The aim of this study was to summarize the interactions between hepatitis C virus (HCV) infection and iron overload, and to understand the mechanisms of iron overload in chronic hepatitis C (CHC) and the role iron plays in HCV life cycle. This review was based on data in articles published in the PubMed databases up to January 28, 2017, with the keywords "hepatitis C virus", "iron overload", "iron metabolism", "hepcidin", "translation", and "replication". Articles related to iron metabolism, iron overload in patients with CHC, or the effects of iron on HCV life cycle were selected for the review. Iron overload is common in patients with CHC. The mechanisms involve decreased hepcidin levels caused by HCV through signal transducer and activator of transcription 3, mitogen-activated protein kinase, or bone morphogenetic protein/SMAD signaling pathways, and the altered expression of other iron-metabolism-related genes. Some studies found that iron increases HCV replication, while other studies found the opposite result. Most of the studies suggest the positive role of iron on HCV translation, the mechanisms of which involve increased expression levels of factors associated with HCV internal ribosome entry site-dependent translation, such as eukaryotic initiation factor 3 and La protein. The growing literature demonstrates that CHC leads to iron overload, and iron affects the HCV life cycle in turn. Further research should be conducted to clarify the mechanism involved in the complicated interaction between iron and HCV.

HLA-B27 Selects for Rare Escape Mutations that Significantly Impair Hepatitis C Virus Replication and Require Compensatory Mutations

PubMed Central

Neumann-Haefelin, Christoph; Oniangue-Ndza, Cesar; Kuntzen, Thomas; Schmidt, Julia; Nitschke, Katja; Sidney, John; Caillet-Saguy, Célia; Binder, Marco; Kersting, Nadine; Kemper, Michael W.; Power, Karen A.; Ingber, Susan; Reyor, Laura L.; Hills-Evans, Kelsey; Kim, Arthur Y.; Lauer, Georg M.; Lohmann, Volker; Sette, Alessandro; Henn, Matthew R.; Bressanelli, Stéphane; Thimme, Robert; Allen, Todd M.

2011-01-01

HLA-B27 is associated with spontaneous viral clearance in hepatitis C virus (HCV) infection. Viral escape within the immunodominant HLA-B27 restricted HCV-specific CD8+ T cell epitope NS5B2841-2849 (ARMILMTHF) has been shown to be limited by viral fitness costs as well as broad T cell cross-recognition, suggesting a potential mechanism of protection by HLA-B27. Here, we studied the subdominant HLA-B27 restricted epitope NS5B2936-2944 (GRAAICGKY) in order to further define the mechanisms of protection by HLA-B27. We identified a unique pattern of escape mutations within this epitope in a large cohort of HCV genotype 1a infected patients. The predominant escape mutations represented conservative substitutions at the main HLA-B27 anchor residue or a T cell receptor contact site, neither of which impaired viral replication capacity as assessed in a subgenomic HCV replicon system. In contrast, however, in a subset of HLA-B27+ subjects rare escape mutations arose at the HLA-B27 anchor residue R2937, which nearly abolished viral replication. Notably, these rare mutations only occurred in conjunction with the selection of two equally rare, and structurally proximal, upstream mutations. Co-expression of these upstream mutations with the rare escape mutations dramatically restored viral replication capacity from <5% to ≥70% of wild-type levels. Conclusion The selection of rare CTL escape mutations in this HLA-B27 restricted epitope dramatically impairs viral replicative fitness unless properly compensated. These data support a role for the targeting of highly-constrained regions by HLA-B27 in its ability to assert immune control of HCV and other highly variable pathogens. PMID:22006856

Internal Disequilibria and Phenotypic Diversification during Replication of Hepatitis C Virus in a Noncoevolving Cellular Environment.

PubMed

Moreno, Elena; Gallego, Isabel; Gregori, Josep; Lucía-Sanz, Adriana; Soria, María Eugenia; Castro, Victoria; Beach, Nathan M; Manrubia, Susanna; Quer, Josep; Esteban, Juan Ignacio; Rice, Charles M; Gómez, Jordi; Gastaminza, Pablo; Domingo, Esteban; Perales, Celia

2017-05-15

Viral quasispecies evolution upon long-term virus replication in a noncoevolving cellular environment raises relevant general issues, such as the attainment of population equilibrium, compliance with the molecular-clock hypothesis, or stability of the phenotypic profile. Here, we evaluate the adaptation, mutant spectrum dynamics, and phenotypic diversification of hepatitis C virus (HCV) in the course of 200 passages in human hepatoma cells in an experimental design that precluded coevolution of the cells with the virus. Adaptation to the cells was evidenced by increase in progeny production. The rate of accumulation of mutations in the genomic consensus sequence deviated slightly from linearity, and mutant spectrum analyses revealed a complex dynamic of mutational waves, which was sustained beyond passage 100. The virus underwent several phenotypic changes, some of which impacted the virus-host relationship, such as enhanced cell killing, a shift toward higher virion density, and increased shutoff of host cell protein synthesis. Fluctuations in progeny production and failure to reach population equilibrium at the genomic level suggest internal instabilities that anticipate an unpredictable HCV evolution in the complex liver environment. IMPORTANCE Long-term virus evolution in an unperturbed cellular environment can reveal features of virus evolution that cannot be explained by comparing natural viral isolates. In the present study, we investigate genetic and phenotypic changes that occur upon prolonged passage of hepatitis C virus (HCV) in human hepatoma cells in an experimental design in which host cell evolutionary change is prevented. Despite replication in a noncoevolving cellular environment, the virus exhibited internal population disequilibria that did not decline with increased adaptation to the host cells. The diversification of phenotypic traits suggests that disequilibria inherent to viral populations may provide a selective advantage to viruses that can be fully exploited in changing environments. Copyright © 2017 American Society for Microbiology.

New therapeutic opportunities for Hepatitis C based on small RNA

PubMed Central

Pan, Qiu-Wei; Henry, Scot D; Scholte, Bob J; Tilanus, Hugo W; Janssen, Harry LA; van der Laan, Luc JW

2007-01-01

Hepatitis C virus (HCV) infection is one of the major causes of chronic liver disease, including cirrhosis and liver cancer and is therefore, the most common indication for liver transplantation. Conventional antiviral drugs such as pegylated interferon-alpha, taken in combination with ribavirin, represent a milestone in the therapy of this disease. However, due to different viral and host factors, clinical success can be achieved only in approximately half of patients, making urgent the requirement of exploiting alternative approaches for HCV therapy. Fortunately, recent advances in the understanding of HCV viral replication and host cell interactions have opened new possibilities for therapeutic intervention. The most recent technologies, such as small interference RNA mediated gene-silencing, anti-sense oligonucleotides (ASO), or viral vector based gene delivery systems, have paved the way to develop novel therapeutic modalities for HCV. In this review, we outline the application of these technologies in the context of HCV therapy. In particular, we will focus on the newly defined role of cellular microRNA (miR-122) in viral replication and discuss its potential for HCV molecular therapy. PMID:17724797

Prospects for nucleic acid-based therapeutics against hepatitis C virus.

PubMed

Lee, Chang Ho; Kim, Ji Hyun; Lee, Seong-Wook

2013-12-21

In this review, we discuss recent advances in nucleic acid-based therapeutic technologies that target hepatitis C virus (HCV) infection. Because the HCV genome is present exclusively in RNA form during replication, various nucleic acid-based therapeutic approaches targeting the HCV genome, such as ribozymes, aptamers, siRNAs, and antisense oligonucleotides, have been suggested as potential tools against HCV. Nucleic acids are potentially immunogenic and typically require a delivery tool to be utilized as therapeutics. These limitations have hampered the clinical development of nucleic acid-based therapeutics. However, despite these limitations, nucleic acid-based therapeutics has clinical value due to their great specificity, easy and large-scale synthesis with chemical methods, and pharmaceutical flexibility. Moreover, nucleic acid therapeutics are expected to broaden the range of targetable molecules essential for the HCV replication cycle, and therefore they may prove to be more effective than existing therapeutics, such as interferon-α and ribavirin combination therapy. This review focuses on the current status and future prospects of ribozymes, aptamers, siRNAs, and antisense oligonucleotides as therapeutic reagents against HCV.

Tannic Acid Inhibits Hepatitis C Virus Entry into Huh7.5 Cells

PubMed Central

Hagedorn, Curt H.

2015-01-01

Chronic infection with the hepatitis C virus (HCV) is a cause of cirrhosis and hepatocellular carcinoma worldwide. Although antiviral therapy has dramatically improved recently, a number of patients remain untreated and some do not clear infection with treatment. Viral entry is an essential step in initiating and maintaining chronic HCV infections. One dramatic example of this is the nearly 100% infection of newly transplanted livers in patients with chronic hepatitis C. HCV entry inhibitors could play a critical role in preventing HCV infection of newly transplanted livers. Tannic acid, a polymer of gallic acid and glucose molecules, is a plant-derived polyphenol that defends some plants from insects and microbial infections. It has been shown to have a variety of biological effects, including antiviral activity, and is used as a flavoring agent in foods and beverages. In this study, we demonstrate that tannic acid is a potent inhibitor of HCV entry into Huh7.5 cells at low concentrations (IC50 5.8 μM). It also blocks cell-to-cell spread in infectious HCV cell cultures, but does not inhibit HCV replication following infection. Moreover, experimental results indicate that tannic acid inhibits an early step of viral entry, such as the docking of HCV at the cell surface. Gallic acid, tannic acid’s structural component, did not show any anti-HCV activity including inhibition of HCV entry or replication at concentrations up to 25 μM. It is possible the tannin structure is related on the effect on HCV inhibition. Tannic acid, which is widely distributed in plants and foods, has HCV antiviral activity in cell culture at low micromolar concentrations, may provide a relative inexpensive adjuvant to direct-acting HCV antivirals and warrants future investigation. PMID:26186636

Hepatitis C, innate immunity and alcohol: friends or foes?

PubMed

Osna, Natalia A; Ganesan, Murali; Kharbanda, Kusum K

2015-02-05

Hepatitis C and alcohol are the most widespread causes of liver disease worldwide. Approximately 80% of patients with a history of hepatitis C and alcohol abuse develop chronic liver injury. Alcohol consumption in hepatitis C virus (HCV)-infected patients exacerbates liver disease leading to rapid progression of fibrosis, cirrhosis and even hepatocellular carcinoma. Hepatocytes are the main sites of HCV-infection and ethanol metabolism, both of which generate oxidative stress. Oxidative stress levels affect HCV replication and innate immunity, resulting in a greater susceptibility for HCV-infection and virus spread in the alcoholic patients. In this review paper, we analyze the effects of ethanol metabolism and other factors on HCV replication. In addition, we illustrate the mechanisms of how HCV hijacks innate immunity and how ethanol exposure regulates this process. We also clarify the effects of HCV and ethanol metabolism on interferon signaling-a crucial point for activation of anti-viral genes to protect cells from virus-and the role that HCV- and ethanol-induced impairments play in adaptive immunity which is necessary for recognition of virally-infected hepatocytes. In conclusion, ethanol exposure potentiates the suppressive effects of HCV on innate immunity, which activates viral spread in the liver and finally, leads to impairments in adaptive immunity. The dysregulation of immune response results in impaired elimination of HCV-infected cells, viral persistence, progressive liver damage and establishment of chronic infection that worsens the outcomes of chronic hepatitis C in alcoholic patients.

Novel Permissive Cell Lines for Complete Propagation of Hepatitis C Virus

PubMed Central

Shiokawa, Mai; Fukuhara, Takasuke; Ono, Chikako; Yamamoto, Satomi; Okamoto, Toru; Watanabe, Noriyuki; Wakita, Takaji

2014-01-01

ABSTRACT Hepatitis C virus (HCV) is a major etiologic agent of chronic liver diseases. Although the HCV life cycle has been clarified by studying laboratory strains of HCV derived from the genotype 2a JFH-1 strain (cell culture-adapted HCV [HCVcc]), the mechanisms of particle formation have not been elucidated. Recently, we showed that exogenous expression of a liver-specific microRNA, miR-122, in nonhepatic cell lines facilitates efficient replication but not particle production of HCVcc, suggesting that liver-specific host factors are required for infectious particle formation. In this study, we screened human cancer cell lines for expression of the liver-specific α-fetoprotein by using a cDNA array database and identified liver-derived JHH-4 cells and stomach-derived FU97 cells, which express liver-specific host factors comparable to Huh7 cells. These cell lines permit not only replication of HCV RNA but also particle formation upon infection with HCVcc, suggesting that hepatic differentiation participates in the expression of liver-specific host factors required for HCV propagation. HCV inhibitors targeting host and viral factors exhibited different antiviral efficacies between Huh7 and FU97 cells. Furthermore, FU97 cells exhibited higher susceptibility for propagation of HCVcc derived from the JFH-2 strain than Huh7 cells. These results suggest that hepatic differentiation participates in the expression of liver-specific host factors required for complete propagation of HCV. IMPORTANCE Previous studies have shown that liver-specific host factors are required for efficient replication of HCV RNA and formation of infectious particles. In this study, we screened human cancer cell lines for expression of the liver-specific α-fetoprotein by using a cDNA array database and identified novel permissive cell lines for complete propagation of HCVcc without any artificial manipulation. In particular, gastric cancer-derived FU97 cells exhibited a much higher susceptibility to HCVcc/JFH-2 infection than observed in Huh7 cells, suggesting that FU97 cells would be useful for further investigation of the HCV life cycle, as well as the development of therapeutic agents for chronic hepatitis C. PMID:24599999

Measuring antiviral activity of benzimidazole molecules that alter IRES RNA structure with an infectious hepatitis C virus chimera expressing Renilla luciferase.

PubMed

Liu, Shuanghu; Nelson, Cassie A; Xiao, Li; Lu, Ling; Seth, Punit P; Davis, Darrell R; Hagedorn, Curt H

2011-01-01

Major progress has been made in developing infectious HCV cell culture systems and these systems have been useful in identifying novel HCV antivirals. However, more rapid and sensitive assays using infectious cell based HCV systems would facilitate the development of additional antivirals, including small molecules directed at unique targets such as the HCV RNA internal ribosomal entry site (IRES). We have found that the V3 region (28 aa) of NS5A of HCV JFH1 can be deleted from the genome with only modest effects on the titer of infectious virus produced in cell culture. Moreover, the V3 region can be replaced with the Renilla reniformis luciferase (Rluc) gene resulting in an infectious virus that stably expresses an NS5A-Rluc fusion protein. Infected cells cultured in 96-well plates provided a robust luciferase signal that accurately reflected the production of infectious virus. This infectious HCV reporter system was used to test the activity of three benzimidazole compounds that bind the HCV RNA IRES. Compounds in this chemical class of small molecules bind and alter the IRES RNA structure at low to sub-micromolar concentrations and interfere with viral replication. The current study shows that these compounds inhibit HCV replication in an infectious HCV cell culture system, defines their IC(50) in this system, and provides a platform for the rapid testing of next generation inhibitors. Copyright © 2010 Elsevier B.V. All rights reserved.

Measuring Antiviral Activity of Benzimidazole Molecules that Alter IRES RNA Structure with an Infectious Hepatitis C Virus Chimera Expressing Renilla Luciferase

PubMed Central

Liu, Shuanghu; Nelson, Cassie A.; Xiao, Li; Lu, Ling; Seth, Punit P.; Davis, Darrell R.; Hagedorn, Curt H.

2010-01-01

Major progress has been made in developing infectious HCV cell culture systems and these systems have been useful in identifying novel HCV antivirals. However, more rapid and sensitive assays using infectious cell based HCV systems would facilitate the development of additional antivirals, including small molecules directed at unique targets such as the HCV RNA internal ribosomal entry site (IRES). We have found that the V3 region (28 aa) of NS5A of HCV JFH1 can be deleted from the genome with only modest effects on the titer of infectious virus produced in cell culture. Moreover, the V3 region can be replaced with the Renilla reniformis luciferase (Rluc) gene resulting in an infectious virus that stably expresses an NS5A-Rluc fusion protein. Infected cells cultured in 96-well plates provided a robust luciferase signal that accurately reflected the production of infectious virus. This infectious HCV reporter system was used to test the activity of three benzimidazole compounds that bind the HCV RNA IRES. Compounds in this chemical class of small molecules bind and alter the IRES RNA structure at low to sub-micromolar concentrations and interfere with viral replication. The current study shows that these compounds inhibit HCV replication in an infectious HCV cell culture system, defines their IC50 in this system, and provides a platform for the rapid testing of next generation inhibitors. PMID:21075143

Immunotherapy of chronic hepatitis C virus infection with antibodies against programmed cell death-1 (PD-1).

PubMed

Fuller, Michael J; Callendret, Benoit; Zhu, Baogong; Freeman, Gordon J; Hasselschwert, Dana L; Satterfield, William; Sharpe, Arlene H; Dustin, Lynn B; Rice, Charles M; Grakoui, Arash; Ahmed, Rafi; Walker, Christopher M

2013-09-10

Hepatitis C virus (HCV) persistence is facilitated by exhaustion of CD8+ T cells that express the inhibitory receptor programmed cell death 1 (PD-1). Blockade of PD-1 signaling improves in vitro proliferation of HCV-specific T lymphocytes, but whether antiviral function can be restored in infected individuals is unknown. To address this question, chimpanzees with persistent HCV infection were treated with anti-PD-1 antibodies. A significant reduction in HCV viremia was observed in one of three treated animals without apparent hepatocellular injury. Viremia rebounded in the responder animal when antibody treatment was discontinued. Control of HCV replication was associated with restoration of intrahepatic CD4+ and CD8+ T-cell immunity against multiple HCV proteins. The responder animal had a history of broader T-cell immunity to multiple HCV proteins than the two chimpanzees that did not respond to PD-1 therapy. The results suggest that successful PD-1 blockade likely requires a critical threshold of preexisting virus-specific T cells in liver and warrants consideration of therapeutic vaccination strategies in combination with PD-1 blockade to broaden narrow responses. Anti-PD-1 immunotherapy may also facilitate control of other persistent viruses, notably the hepatitis B virus where options for long-term control of virus replication are limited.

Small molecule inhibitors of HCV replication from Pomegranate

NASA Astrophysics Data System (ADS)

Reddy, B. Uma; Mullick, Ranajoy; Kumar, Anuj; Sudha, Govindarajan; Srinivasan, Narayanaswamy; Das, Saumitra

2014-06-01

Hepatitis C virus (HCV) is the causative agent of end-stage liver disease. Recent advances in the last decade in anti HCV treatment strategies have dramatically increased the viral clearance rate. However, several limitations are still associated, which warrant a great need of novel, safe and selective drugs against HCV infection. Towards this objective, we explored highly potent and selective small molecule inhibitors, the ellagitannins, from the crude extract of Pomegranate (Punica granatum) fruit peel. The pure compounds, punicalagin, punicalin, and ellagic acid isolated from the extract specifically blocked the HCV NS3/4A protease activity in vitro. Structural analysis using computational approach also showed that ligand molecules interact with the catalytic and substrate binding residues of NS3/4A protease, leading to inhibition of the enzyme activity. Further, punicalagin and punicalin significantly reduced the HCV replication in cell culture system. More importantly, these compounds are well tolerated ex vivo and`no observed adverse effect level' (NOAEL) was established upto an acute dose of 5000 mg/kg in BALB/c mice. Additionally, pharmacokinetics study showed that the compounds are bioavailable. Taken together, our study provides a proof-of-concept approach for the potential use of antiviral and non-toxic principle ellagitannins from pomegranate in prevention and control of HCV induced complications.

Review: Occult hepatitis C virus infection: still remains a controversy.

PubMed

Vidimliski, Pavlina Dzekova; Nikolov, Igor; Geshkovska, Nadica Matevska; Dimovski, Aleksandar; Rostaing, Lionel; Sikole, Aleksandar

2014-09-01

Occult hepatitis C virus (HCV) infection is characterized by the presence of HCV RNA in the liver cells or peripheral blood mononuclear cells of the patients whose serum samples test negative for HCV RNA, with or without presence of HCV antibodies. The present study reviews the existing literature on the persistence of occult hepatitis C virus infection, with description of the clinical characteristics and methods for identification of occult hepatitis C. Occult hepatitis C virus infection was detected in patients with abnormal results of liver function tests of unknown origin, with HCV antibodies and HCV RNA negativity in serum, and also in patients with spontaneous or treatment-induced recovery from hepatitis C. The viral replication in the liver cells and/or peripheral blood mononuclear cells was present in all clinical presentations of occult hepatitis C. The peripheral blood mononuclear cells represent an extra-hepatic site of HCV replication. The reason why HCV RNA was not detectable in the serum of patients with occult hepatitis C, could be the low number of circulating viral particles not detectable by the diagnostic tests with low sensitivity. It is uncertain whether occult hepatitis C is a different clinical entity or just a form of chronic hepatitis C virus infection. Data accumulated over the last decade demonstrated that an effective approach to the diagnosis of HCV infection would be the implementation of more sensitive HCV RNA diagnostic assays, and also, examination of the presence of viral particles in the cells of the immune system. © 2014 Wiley Periodicals, Inc.

Comparative Analysis of the Lambda-Interferons IL-28A and IL-29 regarding Their Transcriptome and Their Antiviral Properties against Hepatitis C Virus

PubMed Central

Diegelmann, Julia; Beigel, Florian; Zitzmann, Kathrin; Kaul, Artur; Göke, Burkhard; Auernhammer, Christoph J.; Bartenschlager, Ralf; Diepolder, Helmut M.; Brand, Stephan

2010-01-01

Background Specific differences in signaling and antiviral properties between the different Lambda-interferons, a novel group of interferons composed of IL-28A, IL-28B and IL-29, are currently unknown. This is the first study comparatively investigating the transcriptome and the antiviral properties of the Lambda-interferons IL-28A and IL-29. Methodology/Principal Findings Expression studies were performed by microarray analysis, quantitative PCR (qPCR), reporter gene assays and immunoluminometric assays. Signaling was analyzed by Western blot. HCV replication was measured in Huh-7 cells expressing subgenomic HCV replicon. All hepatic cell lines investigated as well as primary hepatocytes expressed both IFN-λ receptor subunits IL-10R2 and IFN-λR1. Both, IL-28A and IL-29 activated STAT1 signaling. As revealed by microarray analysis, similar genes were induced by both cytokines in Huh-7 cells (IL-28A: 117 genes; IL-29: 111 genes), many of them playing a role in antiviral immunity. However, only IL-28A was able to significantly down-regulate gene expression (n = 272 down-regulated genes). Both cytokines significantly decreased HCV replication in Huh-7 cells. In comparison to liver biopsies of patients with non-viral liver disease, liver biopsies of patients with HCV showed significantly increased mRNA expression of IL-28A and IL-29. Moreover, IL-28A serum protein levels were elevated in HCV patients. In a murine model of viral hepatitis, IL-28 expression was significantly increased. Conclusions/Significance IL-28A and IL-29 are up-regulated in HCV patients and are similarly effective in inducing antiviral genes and inhibiting HCV replication. In contrast to IL-29, IL-28A is a potent gene repressor. Both IFN-λs may have therapeutic potential in the treatment of chronic HCV. PMID:21170333

Hepatitis C virus replicons: dinosaurs still in business?

PubMed Central

Woerz, I; Lohmann, V; Bartenschlager, R

2009-01-01

Since the molecular cloning of the hepatitis C virus (HCV) genome for the first time in 1989, there has been tremendous progress in our understanding of the multiple facets of the replication cycle of this virus. Key to this progress has been the development of systems to propagate the virus in cell culture, which turned out to be a notoriously difficult task. A major breakthrough has been the construction of subgenomic replicons that self-amplify in cultured human hepatoma cells. These RNAs recapitulate the intracellular steps of the HCV replication cycle and have been instrumental to decipher details of the RNA amplification steps including the identification of key host cell factors. However, reproduction of the complete viral replication cycle only became possible with the advent of a particular molecular HCV clone designated JFH-1 that replicates to very high levels and supports the production of infectious virus particles. The availability of this new culture system raises the question, whether the use of replicons is still justified. In this review, we will discuss the pros and cons of both systems.

Ribavirin Contributes to Hepatitis C Virus Suppression by Augmenting pDC Activation and Type 1 IFN Production.

PubMed

Wang, Yang; McGivern, David R; Cheng, Liang; Li, Guangming; Lemon, Stanley M; Niu, Junqi; Su, Lishan; Reszka-Blanco, Natalia J

2015-01-01

Ribavirin is used as a component of combination therapies for the treatment of chronic hepatitis C virus (HCV) infection together with pegylated interferon and/or direct-acting antiviral drugs. Its mechanism of action, however, is not clear. Direct antiviral activity and immunomodulatory functions have been implicated. Plasmacytoid dendritic cells (pDCs) are the principal source of type 1 interferon during viral infection. The interaction of pDCs with HCV-infected hepatocytes is the subject of intense recent investigation, but the effect of ribavirin on pDC activation has not been evaluated. In this study we showed that ribavirin augments toll-like receptors 7 and 9-mediated IFNα/β expression from pDCs and up-regulated numerous interferon-stimulated genes. Using the H77S.3 HCV infection and replication system, we showed that ribavirin enhanced the ability of activated pDCs to inhibit HCV replication, correlated with elevated induction of IFNα. Our findings provide novel evidence that ribavirin contributes to HCV inhibition by augmenting pDCs-derived type 1 IFN production.

Ribavirin Contributes to Hepatitis C Virus Suppression by Augmenting pDC Activation and Type 1 IFN Production

PubMed Central

Wang, Yang; McGivern, David R; Cheng, Liang; Li, Guangming; Lemon, Stanley M; Niu, Junqi; Su, Lishan; Reszka-Blanco, Natalia J

2015-01-01

Ribavirin is used as a component of combination therapies for the treatment of chronic hepatitis C virus (HCV) infection together with pegylated interferon and/or direct-acting antiviral drugs. Its mechanism of action, however, is not clear. Direct antiviral activity and immunomodulatory functions have been implicated. Plasmacytoid dendritic cells (pDCs) are the principal source of type 1 interferon during viral infection. The interaction of pDCs with HCV-infected hepatocytes is the subject of intense recent investigation, but the effect of ribavirin on pDC activation has not been evaluated. In this study we showed that ribavirin augments toll-like receptors 7 and 9-mediated IFNα/β expression from pDCs and up-regulated numerous interferon-stimulated genes. Using the H77S.3 HCV infection and replication system, we showed that ribavirin enhanced the ability of activated pDCs to inhibit HCV replication, correlated with elevated induction of IFNα. Our findings provide novel evidence that ribavirin contributes to HCV inhibition by augmenting pDCs-derived type 1 IFN production. PMID:26274905

Hepatitis C Virus Genotype 1 to 6 Protease Inhibitor Escape Variants: In Vitro Selection, Fitness, and Resistance Patterns in the Context of the Infectious Viral Life Cycle

PubMed Central

Serre, Stéphanie B. N.; Jensen, Sanne B.; Ghanem, Lubna; Humes, Daryl G.; Ramirez, Santseharay; Li, Yi-Ping; Krarup, Henrik; Bukh, Jens

2016-01-01

Hepatitis C virus (HCV) NS3 protease inhibitors (PIs) are important components of novel HCV therapy regimens. Studies of PI resistance initially focused on genotype 1. Therefore, knowledge about the determinants of PI resistance for the highly prevalent genotypes 2 to 6 remains limited. Using Huh7.5 cell culture-infectious HCV recombinants with genotype 1 to 6 NS3 protease, we identified protease positions 54, 155, and 156 as hot spots for the selection of resistance substitutions under treatment with the first licensed PIs, telaprevir and boceprevir. Treatment of a genotype 2 isolate with the newer PIs vaniprevir, faldaprevir, simeprevir, grazoprevir, paritaprevir, and deldeprevir identified positions 156 and 168 as hot spots for resistance; the Y56H substitution emerged for three newer PIs. Substitution selection also depended on the specific recombinant. The substitutions identified conferred cross-resistance to several PIs; however, most substitutions selected under telaprevir or boceprevir treatment conferred less resistance to certain newer PIs. In a single-cycle production assay, across genotypes, PI treatment primarily decreased viral replication, which was rescued by PI resistance substitutions. The substitutions identified resulted in differential effects on viral fitness, depending on the original recombinant and the substitution. Across genotypes, fitness impairment induced by resistance substitutions was due primarily to decreased replication. Most combinations of substitutions that were identified increased resistance or fitness. Combinations of resistance substitutions with fitness-compensating substitutions either rescued replication or compensated for decreased replication by increasing assembly. This comprehensive study provides insight into the selection patterns and effects of PI resistance substitutions for HCV genotypes 1 to 6 in the context of the infectious viral life cycle, which is of interest for clinical and virological HCV research. PMID:27021330

Hepatitis C virus stimulates low-density lipoprotein receptor expression to facilitate viral propagation.

PubMed

Syed, Gulam Hussain; Tang, Huihui; Khan, Mohsin; Hassanein, Tarek; Liu, Jingwen; Siddiqui, Aleem

2014-03-01

Lipids play a crucial role in multiple aspects of hepatitis C virus (HCV) life cycle. HCV modulates host lipid metabolism to enrich the intracellular milieu with lipids to facilitate its proliferation. However, very little is known about the influence of HCV on lipid uptake from bloodstream. Low-density lipoprotein receptor (LDLR) is involved in uptake of cholesterol rich low-density lipoprotein (LDL) particles from the bloodstream. The association of HCV particles with lipoproteins implicates their role in HCV entry; however, the precise role of LDLR in HCV entry still remains controversial. Here, we investigate the effect of HCV infection on LDLR expression and the underlying mechanism(s) involved. We demonstrate that HCV stimulates LDLR expression in both HCV-infected Huh7 cells and in liver tissue from chronic hepatitis C patients. Fluorescence activated cell sorting and immunofluorescence analysis revealed enhanced cell surface and total expression of LDLR in HCV-infected cells. Increased LDLR expression resulted in the enhanced uptake of lipoprotein particles by HCV-infected cells. Analysis of LDLR gene promoter identified a pivotal role of sterol-regulatory element binding proteins (SREBPs), in the HCV-mediated stimulation of LDLR transcription. In addition, HCV negatively modulated the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), a protein that facilitates LDLR degradation. Ectopic expression of wild-type PCSK9 or gain-of-function PCSK9 mutant negatively affected HCV replication. Overall, our results demonstrate that HCV regulates LDLR expression at transcriptional and posttranslational level via SREBPs and PCSK9 to promote lipid uptake and facilitate viral proliferation. HCV modulates host lipid metabolism to promote enrichment of lipids in intracellular environment, which are essential in multiple aspects of HCV life cycle. However, very little is known about the influence of HCV on lipid uptake from the bloodstream. LDLR is involved in uptake of cholesterol rich lipid particles from bloodstream. In this study, we investigated the effect of HCV on LDLR expression and the underlying mechanism triggered by the virus to modulate LDLR expression. Our observations suggest that HCV upregulates LDLR expression at both the protein and the transcript levels and that this upregulation likely contributes toward the uptake of serum lipids by infected hepatocytes. Abrogation of HCV-mediated upregulation of LDLR inhibits serum lipid uptake and thereby perturbs HCV replication. Overall, our findings highlight the importance of serum lipid uptake by infected hepatocytes in HCV life cycle.

Evaluation of Interferon Resistance in Newly Established Genotype 1b Hepatitis C Virus Cell Culture System

PubMed Central

Taniguchi, Miki; Tasaka-Fujita, Megumi; Nakagawa, Mina; Watanabe, Takako; Kawai-Kitahata, Fukiko; Otani, Satoshi; Goto, Fumio; Nagata, Hiroko; Kaneko, Shun; Nitta, Sayuri; Murakawa, Miyako; Nishimura-Sakurai, Yuki; Azuma, Seishin; Itsui, Yasuhiro; Mori, Kenichi; Yagi, Shintaro; Kakinuma, Sei; Asahina, Yasuhiro; Watanabe, Mamoru

2016-01-01

Background and Aims: The hepatitis C virus (HCV) genotype 1b is known to exhibit treatment resistance with respect to interferon (IFN) therapy. Substitution of amino acids 70 and 91 in the core region of the 1b genotype is a significant predictor of liver carcinogenesis and poor response to pegylated-IFN-α and ribavirin therapy. However, the molecular mechanism has not yet been clearly elucidated because of limitations of the HCV genotype 1b infectious model. Recently, the TPF1-M170T HCV genotype 1b cell culture system was established, in which the clone successfully replicates and infects Huh-7-derived Huh7-ALS32.50 cells. Therefore, the purpose of this study was to compare IFN resistance in various HCV clones using this system. Methods: HCV core amino acid substitutions R70Q and L91M were introduced to the TPF1-M170T clone and then transfected into Huh7-ALS32.50 cells. To evaluate the production of each virus, intracellular HCV core antigens were measured. Results were confirmed with Western blot analysis using anti-NS5A antibodies, and IFN sensitivity was subsequently measured. Results: Each clone was transfected successfully compared with JFH-1, with a significant difference in intracellular HCV core antigen (p < 0.05), an indicator of continuous HCV replication. Among all clones, L91M showed the highest increase in the HCV core antigen and HCV protein. There was no significant resistance against IFN treatment in core substitutions; however, IFN sensitivity was significantly different between the wildtype core and JFH-1 (p < 0.05). Conclusions: A novel genotype 1b HCV cell culture was constructed with core amino acid substitutions, which demonstrated IFN resistance of genotype 1b. This system will be useful for future analyses into the mechanisms of HCV genotype 1b treatment. PMID:27047766

Efficient infectious cell culture systems of the hepatitis C virus (HCV) prototype strains HCV-1 and H77.

PubMed

Li, Yi-Ping; Ramirez, Santseharay; Mikkelsen, Lotte; Bukh, Jens

2015-01-01

The first discovered and sequenced hepatitis C virus (HCV) genome and the first in vivo infectious HCV clones originated from the HCV prototype strains HCV-1 and H77, respectively, both widely used in research of this important human pathogen. In the present study, we developed efficient infectious cell culture systems for these genotype 1a strains by using the HCV-1/SF9_A and H77C in vivo infectious clones. We initially adapted a genome with the HCV-1 5'UTR-NS5A (where UTR stands for untranslated region) and the JFH1 NS5B-3'UTR (5-5A recombinant), including the genotype 2a-derived mutations F1464L/A1672S/D2979G (LSG), to grow efficiently in Huh7.5 cells, thus identifying the E2 mutation S399F. The combination of LSG/S399F and reported TNcc(1a)-adaptive mutations A1226G/Q1773H/N1927T/Y2981F/F2994S promoted adaptation of the full-length HCV-1 clone. An HCV-1 recombinant with 17 mutations (HCV1cc) replicated efficiently in Huh7.5 cells and produced supernatant infectivity titers of 10(4.0) focus-forming units (FFU)/ml. Eight of these mutations were identified from passaged HCV-1 viruses, and the A970T/I1312V/C2419R/A2919T mutations were essential for infectious particle production. Using CD81-deficient Huh7 cells, we further demonstrated the importance of A970T/I1312V/A2919T or A970T/C2419R/A2919T for virus assembly and that the I1312V/C2419R combination played a major role in virus release. Using a similar approach, we found that NS5B mutation F2994R, identified here from culture-adapted full-length TN viruses and a common NS3 helicase mutation (S1368P) derived from viable H77C and HCV-1 5-5A recombinants, initiated replication and culture adaptation of H77C containing LSG and TNcc(1a)-adaptive mutations. An H77C recombinant harboring 19 mutations (H77Ccc) replicated and spread efficiently after transfection and subsequent infection of naive Huh7.5 cells, reaching titers of 10(3.5) and 10(4.4) FFU/ml, respectively. Hepatitis C virus (HCV) was discovered in 1989 with the cloning of the prototype strain HCV-1 genome. In 1997, two molecular clones of H77, the other HCV prototype strain, were shown to be infectious in chimpanzees, but not in vitro. HCV research was hampered by a lack of infectious cell culture systems, which became available only in 2005 with the discovery of JFH1 (genotype 2a), a genome that could establish infection in Huh7.5 cells. Recently, we developed in vitro infectious clones for genotype 1a (TN), 2a (J6), and 2b (J8, DH8, and DH10) strains by identifying key adaptive mutations. Globally, genotype 1 is the most prevalent. Studies using HCV-1 and H77 prototype sequences have generated important knowledge on HCV. Thus, the in vitro infectious clones developed here for these 1a strains will be of particular value in advancing HCV research. Moreover, our findings open new avenues for the culture adaptation of HCV isolates of different genotypes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Requirement for Chloride Channel Function during the Hepatitis C Virus Life Cycle

PubMed Central

Igloi, Zsofia; Mohl, Bjorn-Patrick; Lippiat, Jonathan D.; Harris, Mark

2015-01-01

Hepatocytes express an array of plasma membrane and intracellular ion channels, yet their role during the hepatitis C virus (HCV) life cycle remains largely undefined. Here, we show that HCV increases intracellular hepatic chloride (Cl−) influx that can be inhibited by selective Cl− channel blockers. Through pharmacological and small interfering RNA (siRNA)-mediated silencing, we demonstrate that Cl− channel inhibition is detrimental to HCV replication. This represents the first observation of the involvement of Cl− channels during the HCV life cycle. PMID:25609806

The hepatitis C virus Core protein is a potent nucleic acid chaperone that directs dimerization of the viral (+) strand RNA in vitro

PubMed Central

Cristofari, Gaël; Ivanyi-Nagy, Roland; Gabus, Caroline; Boulant, Steeve; Lavergne, Jean-Pierre; Penin, François; Darlix, Jean-Luc

2004-01-01

The hepatitis C virus (HCV) is an important human pathogen causing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped virus with a positive-sense, single-stranded RNA genome encoding a single polyprotein that is processed to generate viral proteins. Several hundred molecules of the structural Core protein are thought to coat the genome in the viral particle, as do nucleocapsid (NC) protein molecules in Retroviruses, another class of enveloped viruses containing a positive-sense RNA genome. Retroviral NC proteins also possess nucleic acid chaperone properties that play critical roles in the structural remodelling of the genome during retrovirus replication. This analogy between HCV Core and retroviral NC proteins prompted us to investigate the putative nucleic acid chaperoning properties of the HCV Core protein. Here we report that Core protein chaperones the annealing of complementary DNA and RNA sequences and the formation of the most stable duplex by strand exchange. These results show that the HCV Core is a nucleic acid chaperone similar to retroviral NC proteins. We also find that the Core protein directs dimerization of HCV (+) RNA 3′ untranslated region which is promoted by a conserved palindromic sequence possibly involved at several stages of virus replication. PMID:15141033

The hepatitis C virus Core protein is a potent nucleic acid chaperone that directs dimerization of the viral (+) strand RNA in vitro.

PubMed

Cristofari, Gaël; Ivanyi-Nagy, Roland; Gabus, Caroline; Boulant, Steeve; Lavergne, Jean-Pierre; Penin, François; Darlix, Jean-Luc

2004-01-01

The hepatitis C virus (HCV) is an important human pathogen causing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped virus with a positive-sense, single-stranded RNA genome encoding a single polyprotein that is processed to generate viral proteins. Several hundred molecules of the structural Core protein are thought to coat the genome in the viral particle, as do nucleocapsid (NC) protein molecules in Retroviruses, another class of enveloped viruses containing a positive-sense RNA genome. Retroviral NC proteins also possess nucleic acid chaperone properties that play critical roles in the structural remodelling of the genome during retrovirus replication. This analogy between HCV Core and retroviral NC proteins prompted us to investigate the putative nucleic acid chaperoning properties of the HCV Core protein. Here we report that Core protein chaperones the annealing of complementary DNA and RNA sequences and the formation of the most stable duplex by strand exchange. These results show that the HCV Core is a nucleic acid chaperone similar to retroviral NC proteins. We also find that the Core protein directs dimerization of HCV (+) RNA 3' untranslated region which is promoted by a conserved palindromic sequence possibly involved at several stages of virus replication.

Hepatitis C virus RNA elimination and development of resistance in replicon cells treated with BMS-790052.

PubMed

Wang, Chunfu; Huang, Haichang; Valera, Lourdes; Sun, Jin-Hua; O'Boyle, Donald R; Nower, Peter T; Jia, Lingling; Qiu, Dike; Huang, Xin; Altaf, Aneela; Gao, Min; Fridell, Robert A

2012-03-01

BMS-790052, a first-in-class hepatitis C virus (HCV) replication complex inhibitor, targeting nonstructural protein 5A (NS5A), displays picomolar to nanomolar potency against genotypes 1 to 5. This exceptional potency translated into robust anti-HCV activity in clinical studies with HCV genotype 1-infected subjects. To date, all BMS-790052-associated resistance mutations have mapped to the N-terminal region of NS5A. To further characterize the antiviral activity of BMS-790052, HCV replicon elimination and colony formation assays were performed. Replicon was cleared from genotype 1a and 1b replicon cells in a time- and dose-dependent manner. Elimination of the genotype 1a replicon required longer treatment durations and higher concentrations of BMS-790052 than those for the genotype1b replicon. Single amino acid substitutions that conferred relatively low levels of resistance were observed at early time points and at low doses. Higher doses and longer treatment durations yielded mutations that conferred greater levels of resistance, including linked amino acid substitutions. Replicon cells that survived inhibitor treatment remained fully sensitivity to pegylated alpha interferon (pegIFN-α) and other HCV inhibitors. Moreover, genotype 1a replicon elimination was markedly enhanced when pegIFN-α and BMS-790052 were combined. Resistant variants observed in this study were very similar to those observed in a multiple ascending dose (MAD) monotherapy trial of BMS-790052, validating replicon elimination studies as a model to predict clinical resistance. Insights gained from the in vitro anti-HCV activity and resistance profiles of BMS-790052 will be used to help guide the clinical development of this novel HCV inhibitor.

HLA-DQB1*03 Confers Susceptibility to Chronic Hepatitis C in Japanese: A Genome-Wide Association Study

PubMed Central

Takahashi, Atsushi; Hayes, C. Nelson; Urabe, Yuji; Abe, Hiromi; Kawaoka, Tomokazu; Tsuge, Masataka; Hiraga, Nobuhiko; Imamura, Michio; Kawakami, Yoshiiku; Aikata, Hiroshi; Takahashi, Shoichi; Akuta, Norio; Suzuki, Fumitaka; Ikeda, Kenji; Kumada, Hiromitsu; Karino, Yoshiyasu; Toyota, Joji; Tsunoda, Tatsuhiko; Kubo, Michiaki; Kamatani, Naoyuki; Nakamura, Yusuke; Chayama, Kazuaki

2013-01-01

Hepatitis C virus (HCV) establishes a chronic infection in 70-80% of infected individuals. Many researchers have examined the effect of human leukocyte antigen (HLA) on viral persistence because of its critical role in the immune response against exposure to HCV, but almost all studies have proven to be inconclusive. To identify genetic risk factors for chronic HCV infection, we analyzed 458,207 single nucleotide polymorphisms (SNPs) in 481 chronic HCV patients and 2,963 controls in a Japanese cohort. Next, we performed a replication study with an independent panel of 4,358 cases and 1,114 controls. We further confirmed the association in 1,379 cases and 25,817 controls. In the GWAS phase, we found 17 SNPs that showed suggestive association (P < 1 × 10-5). After the first replication study, we found one intronic SNP in the HLA-DQ locus associated with chronic HCV infection, and when we combined the two studies, the association reached the level of genome-wide significance. In the second replication study, we again confirmed the association (P combined = 3.59 × 10−16, odds ratio [OR] = 0.79). Subsequent analysis revealed another SNP, rs1130380, with a stronger association (OR=0.72). This nucleotide substitution causes an amino acid substitution (R55P) in the HLA-DQB1 protein specific to the DQB1*03 allele, which is common worldwide. In addition, we confirmed an association with the previously reported IFNL3-IFNL4 locus and propose that the effect of DQB1*03 on HCV persistence might be affected by the IFNL4 polymorphism. Our findings suggest that a common amino acid substitution in HLA-DQB1 affects susceptibility to chronic infection with HCV in the Japanese population and may not be independent of the IFNL4 genotype. PMID:24376798

Rituximab-based treatment, HCV replication, and hepatic flares.

PubMed

Sagnelli, Evangelista; Pisaturo, Mariantonietta; Sagnelli, Caterina; Coppola, Nicola

2012-01-01

Rituximab, a chimeric mouse-human monoclonal antibody directed to the CD20 antigen expressed on pre-B lymphocytes and mature lymphocytes, causes a profound B-cell depletion. Due to its peculiar characteristics, this drug has been used to treat oncohaematological diseases, B cell-related autoimmune diseases, rheumatoid arthritis, and, more recently, HCV-associated mixed cryoglobulinaemic vasculitis. Rituximab-based treatment, however, may induce an increased replication of several viruses such as hepatitis B virus, cytomegalovirus, varicella-zoster virus, echovirus, and parvovirus B19. Recent data suggest that rituximab-based chemotherapy induces an increase in HCV expression in hepatic cells, which may become a target for a cell-mediated immune reaction after the withdrawal of treatment and the restoration of the immune control. Only a few small studies have investigated the occurrence of HCV reactivation and an associated hepatic flare in patients with oncohaematological diseases receiving R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). These studies suggest that the hepatic flares are frequently asymptomatic, but life-threatening liver failure occurs in nearly 10% of cases.

Hepatitis C in HIV-infected individuals: a systematic review and meta-analysis of estimated prevalence in Africa.

PubMed

Azevedo, Tiago Castro Lopes; Zwahlen, Marcel; Rauch, Andri; Egger, Matthias; Wandeler, Gilles

2016-01-01

Although hepatitis C virus (HCV) screening is recommended for all HIV-infected patients initiating antiretroviral therapy, data on epidemiologic characteristics of HCV infection in resource-limited settings are scarce. We searched PubMed and EMBASE for studies assessing the prevalence of HCV infection among HIV-infected individuals in Africa and extracted data on laboratory methods used. Prevalence estimates from individual studies were combined for each country using random-effects meta-analysis. The importance of study design, population and setting as well as type of test (anti-HCV antibody tests and polymerase chain reactions) was examined with meta-regression. Three randomized controlled trials, 28 cohort studies and 121 cross-sectional analyses with 108,180 HIV-infected individuals from 35 countries were included. The majority of data came from outpatient populations (55%), followed by blood donors (15%) and pregnant women (14%). Based on estimates from 159 study populations, anti-HCV positivity prevalence ranged between 3.3% (95% confidence interval (CI) 1.8-4.7) in Southern Africa and 42.3% (95% CI 4.1-80.5) in North Africa. Study design, type of setting and age distribution did not influence this prevalence significantly. The prevalence of replicating HCV infection, estimated from data of 29 cohorts, was 2.0% (95% CI 1.5-2.6). Ten studies from nine countries reported the HCV genotype of 74 samples, 53% were genotype 1, 24% genotype 2, 14% genotype 4 and 9% genotypes 3, 5 or 6. The prevalence of anti-HCV antibodies is high in HIV-infected patients in Africa, but replicating HCV infection is rare and varies widely across countries.

Novel Cell Culture-Adapted Genotype 2a Hepatitis C Virus Infectious Clone

PubMed Central

Date, Tomoko; Kato, Takanobu; Kato, Junko; Takahashi, Hitoshi; Morikawa, Kenichi; Akazawa, Daisuke; Murayama, Asako; Tanaka-Kaneko, Keiko; Sata, Tetsutaro; Tanaka, Yasuhito; Mizokami, Masashi

2012-01-01

Although the recently developed infectious hepatitis C virus system that uses the JFH-1 clone enables the study of whole HCV viral life cycles, limited particular HCV strains have been available with the system. In this study, we isolated another genotype 2a HCV cDNA, the JFH-2 strain, from a patient with fulminant hepatitis. JFH-2 subgenomic replicons were constructed. HuH-7 cells transfected with in vitro transcribed replicon RNAs were cultured with G418, and selected colonies were isolated and expanded. From sequencing analysis of the replicon genome, several mutations were found. Some of the mutations enhanced JFH-2 replication; the 2217AS mutation in the NS5A interferon sensitivity-determining region exhibited the strongest adaptive effect. Interestingly, a full-length chimeric or wild-type JFH-2 genome with the adaptive mutation could replicate in Huh-7.5.1 cells and produce infectious virus after extensive passages of the virus genome-replicating cells. Virus infection efficiency was sufficient for autonomous virus propagation in cultured cells. Additional mutations were identified in the infectious virus genome. Interestingly, full-length viral RNA synthesized from the cDNA clone with these adaptive mutations was infectious for cultured cells. This approach may be applicable for the establishment of new infectious HCV clones. PMID:22787209

Anti-hepatitis C virus activity and synergistic effect of Nymphaea alba extracts and bioactive constituents in liver infected cells.

PubMed

Rehman, Sidra; Ashfaq, Usman Ali; Ijaz, Bushra; Riazuddin, Sheikh

2018-05-28

Without an effective vaccine, hepatitis C virus (HCV) remains a global threat, inflicting 170-300 million carriers worldwide at risk of cirrhosis and hepatocellular carcinoma (HCC). Though various direct acting antivirals have been redeemed the hepatitis C treatment, a few restraints persist including possible side effects, viral resistance emergence, excessive cost which restricts its availability to a common person. There is no preventive HCV vaccine available today so the discovery of potent antiviral natural flora and their bioactive constituents may help to develop preventive cures against HCV infection. In current study, we aim to clarify anti-HCV activity of methanol and acetone extracts along with the purified fractions of Pakistani local plant, Nymphaea alba L (N. alba) using Huh-7 cell line as transfection model. Synergistic study of purified fractions with interferon was performed using MDBK cell line (expressing interferon receptors) as transfection model. Recent study by our research group has observed potent anti-HCV NS3 protease activity of methanol and acetone extracts of N. alba. Effect of N. alba extracts, its fractions precisely, the N1 and N8 fractions on HCV replication was demonstrated by analyzing viral gene expression using in vitro transfection model. Considering NS3 protease as a dynamic drug target, fourteen phytochemicals of N. alba were selected as ligands for interaction with NS3 protein using Molecular Operating Environment (MOE) software. Boceprevir, FDA approved NS3 protease inhibitor, was used as standard for comparative study in docking screening. Herein we report 84% and 94% reduction of 3a genotype of HCV NS3/4A gene expression at mRNA level at non-toxic concentration. Specifically, two fractions 'N1' & 'N8' isolated from acetone extract suppressed HCV NS3 gene expression in transfected target cells with an EC 50 value of 37 ± 0.03 μg/ml and 20 ± 0.02 μg/ml respectively. Similarly, viral genotype 1a replication is strongly suppressed in target cells by N. alba flower extracts and purified fractions. Moreover, combination of fractions with standard antiviral drug displayed synergistic effects for inhibition of HCV replication. Phytochemicals including Isoquercetin, Hyperoside, Quercetin, Reynoutrin, Apigenin and Isokaempferide displayed minimum binding energies as compared to standard protease inhibitor. N. alba and its purified phytochemicals with new scaffolds might significantly serve as valuable and alternative regimen against HCV either alone or in combination with other potential anti-HCV agents. Copyright © 2018 Elsevier Ltd. All rights reserved.

Therapeutic potential of Taraxacum officinale against HCV NS5B polymerase: In-vitro and In silico study.

PubMed

Rehman, Sidra; Ijaz, Bushra; Fatima, Nighat; Muhammad, Syed Aun; Riazuddin, Sheikh

2016-10-01

Discovery of alternative and complementary regimens for HCV infection treatment is a need of time from clinical as well as economical point of views. Low cost of bioactive natural compounds production, high biochemical diversity and inexistent/milder side effects contribute to new therapies. Aim of this study is to clarify anti-HCV role of Taraxacum officinale, a natural habitat plant rich of flavonoids. In this study, methanol extract of T. officinale leaves was initially analyzed for its cytotoxic activity in human hepatoma (Huh-7) and CHO cell lines. Hepatoma cells were transfected with pCR3.1/Flagtag/HCV NS5B gene cloned vector (genotype 1a) along with T. officinale extract. Considering NS5B polymerase as potential therapeutic drug target, twelve phytochemicals of T. officinale were selected as ligands for molecular interaction with NS5B protein using Molecular Operating Environment (MOE) software. Sofosbuvir (Sovaldi: brand name) currently approved as new anti-HCV drug, was used as standard in current study for comparative analysis in computational docking screening. HCV NS5B polymerase as name indicates plays key role in viral genome replication. On the basis of which NS5B gene is targeted for determining antiviral role of T. officinale extract and 65% inhibition of NS5B expression was documented at nontoxic dose concentration (200μg/ml) using Real-time PCR. In addition, 57% inhibition of HCV replication was recorded when incubating Huh-7 cells with high titer serum of HCV infected patients along with leaves extract. Phytochemicals for instance d-glucopyranoside (-31.212 Kcal/mol), Quercetin (-29.222 Kcal/mol), Luteolin (-26.941 Kcal/mol) and some others displayed least binding energies as compared to standard drug Sofosbuvir (-21.0746 Kcal/mol). Results of our study strongly revealed that T. officinale leaves extract potentially blocked the viral replication and NS5B gene expression without posing any toxic effect on normal fibroblast cells of body. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Rethinking the old antiviral drug moroxydine: Discovery of novel analogues as anti-hepatitis C virus (HCV) agents.

PubMed

Magri, Andrea; Reilly, Roisin; Scalacci, Nicolò; Radi, Marco; Hunter, Michael; Ripoll, Manon; Patel, Arvind H; Castagnolo, Daniele

2015-11-15

The discovery of a novel class of HCV inhibitors is described. The new amidinourea compounds were designed as isosteric analogues of the antiviral drug moroxydine. The two derivatives 11g and 11h showed excellent HCV inhibition activity and viability and proved to inhibit a step(s) of the RNA replication. The new compounds have been synthesized in only three synthetic steps from cheap building blocks and in high yields, thus turning to be promising drug candidates in the development of cheaper HCV treatments. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Association of IL-10-1082 and IL-10-592 polymorphisms with chronic hepatitis B and/or hepatitis C virus infection among plasma donors in a rural area of Hebei Province, China].

PubMed

Gao, Qiuju; Zhang, Shiyong; Wu, Lihong; Jia, Min; Mi, Yu; Liu, Dianwu

2011-11-01

To study the relationship between the polymorphisms of interleukin-10 gene at position--1082,-592 (IL-10-1082, IL-10-592) and chronic HBV and/or HCV infection. 277 subjects (79 chronic HCV/HBV co-infection,69 chronic HBV infection, 55 chronic HCV infection and 74 control subjects) were recruited from plasma donors in a rural area of Hebei Province, China. The single nucleotide polymorphism of IL-10-1082 and IL-10-592 was investigated by sequence specific primer-PCR (SSP-PCR) and restricted fragment long polymorphism-PCR (RFLP-PCR). Hepatocellular injury was detected by alanine aminotransferase (ALT) with Beckman LX-20 analyzer. The presence of hepatitis C viral particles in serum was determined by RT-nPCR. (1) Chronic HCV or HBV infection or HCV/HBV co-infection was associated with higher frequency of IL-10-1082 AA genotype [chi2 = 13.05, P = 0.04; OR = 2.29 (1.10-4.78), 2.34 (1.07-5.10), 2.56 (1.25 -5.21)]. There was no significant association of IL-10-1082 allele frequency with HCV or HBV infection or HCV/HBV co-infections (chi2 = 4.65, P = 0.20). There was no significant association of IL-10-592 genotype and allele frequency with chronic HBV and/or HCV infection (chi2 = 2.83, P = 0.83; chi2 = 1.10, P = 0.78) (2) There were obvious associations of higher IL-10-1082 AA genotype and A allele frequency with HCV replication [(chi2 = 12.27, P = 0.00; chi2 = 5.36, P = 0.02), OR = 3.36 (1.67-6.76) and 1.67 (1.08-2.57)]. The polymorphism of IL-10592 was not associated with HCV RNA replication (chi2 = 2.10, P = 0.35; chi2 = 1.88, P = 0.17). (3) The polymorphism of IL-10-1082 was not significantly associated with abnormal ALT (chi2 = 3.25, P = 0.20; chi2 = 1.79, P = 0.18). Abnormal serum ALT level was associated with IL-10-592 AC genotype [(chi2 = 6.32, P = 0.04), OR = 2.83 (1.26- 6.37)), but the IL-10-592 A/C allele frequency was not associated with abnormal serum ALT level (chi2 = 2.30, P = 0.09). These results suggested that the polymorphism of IL-10-1082 appears to have some influences on the chronic infection of HCV and/or HBV and HCV replication. IL-10-592 AC genotype frequency has influence on inflammatory liver injury.

Quantification of HCV RNA in Clinical Specimens by Branched DNA (bDNA) Technology.

PubMed

Wilber, J C; Urdea, M S

1999-01-01

The diagnosis and monitoring of hepatitis C virus (HCV) infection have been aided by the development of HCV RNA quantification assays A direct measure of viral load, HCV RNA quantification has the advantage of providing information on viral kinetics and provides unique insight into the disease process. Branched DNA (bDNA) signal amplification technology provides a novel approach for the direct quantification of HCV RNA in patient specimens. The bDNA assay measures HCV RNA at physiological levels by boosting the reporter signal, rather than by replicating target sequences as the means of detection, and thus avoids the errors inherent in the extraction and amplification of target sequences. Inherently quantitative and nonradioactive, the bDNA assay is amenable to routine use in a clinical research setting, and has been used by several groups to explore the natural history, pathogenesis, and treatment of HCV infection.

Hepatitis C Virus Genotype 1 to 6 Protease Inhibitor Escape Variants: In Vitro Selection, Fitness, and Resistance Patterns in the Context of the Infectious Viral Life Cycle.

PubMed

Serre, Stéphanie B N; Jensen, Sanne B; Ghanem, Lubna; Humes, Daryl G; Ramirez, Santseharay; Li, Yi-Ping; Krarup, Henrik; Bukh, Jens; Gottwein, Judith M

2016-06-01

Hepatitis C virus (HCV) NS3 protease inhibitors (PIs) are important components of novel HCV therapy regimens. Studies of PI resistance initially focused on genotype 1. Therefore, knowledge about the determinants of PI resistance for the highly prevalent genotypes 2 to 6 remains limited. Using Huh7.5 cell culture-infectious HCV recombinants with genotype 1 to 6 NS3 protease, we identified protease positions 54, 155, and 156 as hot spots for the selection of resistance substitutions under treatment with the first licensed PIs, telaprevir and boceprevir. Treatment of a genotype 2 isolate with the newer PIs vaniprevir, faldaprevir, simeprevir, grazoprevir, paritaprevir, and deldeprevir identified positions 156 and 168 as hot spots for resistance; the Y56H substitution emerged for three newer PIs. Substitution selection also depended on the specific recombinant. The substitutions identified conferred cross-resistance to several PIs; however, most substitutions selected under telaprevir or boceprevir treatment conferred less resistance to certain newer PIs. In a single-cycle production assay, across genotypes, PI treatment primarily decreased viral replication, which was rescued by PI resistance substitutions. The substitutions identified resulted in differential effects on viral fitness, depending on the original recombinant and the substitution. Across genotypes, fitness impairment induced by resistance substitutions was due primarily to decreased replication. Most combinations of substitutions that were identified increased resistance or fitness. Combinations of resistance substitutions with fitness-compensating substitutions either rescued replication or compensated for decreased replication by increasing assembly. This comprehensive study provides insight into the selection patterns and effects of PI resistance substitutions for HCV genotypes 1 to 6 in the context of the infectious viral life cycle, which is of interest for clinical and virological HCV research. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Sensitive luminescent reporter viruses reveal appreciable release of hepatitis C virus NS5A protein into the extracellular environment.

PubMed

Eyre, Nicholas S; Aloia, Amanda L; Joyce, Michael A; Chulanetra, Monrat; Tyrrell, D Lorne; Beard, Michael R

2017-07-01

The HCV NS5A protein is essential for viral RNA replication and virus particle assembly. To study the viral replication cycle and NS5A biology we generated an infectious HCV construct with a NanoLuciferase (NLuc) insertion within NS5A. Surprisingly, beyond its utility as a sensitive reporter of cytoplasmic viral RNA replication, we also observed strong luminescence in cell culture fluids. Further analysis using assembly-defective viruses and subgenomic replicons revealed that infectious virus production was not required for extracellular NS5A-NLuc activity but was associated with enrichment of extracellular NS5A-NLuc in intermediate-density fractions similar to those of exosomes and virus particles. Additionally, BRET analysis indicated that intracellular and extracellular forms of NS5A may adopt differing conformations. Importantly, infection studies using a human liver chimeric mouse model confirmed robust infection in vivo and ready detection of NLuc activity in serum. We hypothesise that the presence of NS5A in extracellular fluids contributes to HCV pathogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Detergent-resistant membrane association of NS2 and E2 during hepatitis C virus replication.

PubMed

Shanmugam, Saravanabalaji; Saravanabalaji, Dhanaranjani; Yi, MinKyung

2015-04-01

Previously, we demonstrated that the efficiency of hepatitis C virus (HCV) E2-p7 processing regulates p7-dependent NS2 localization to putative virus assembly sites near lipid droplets (LD). In this study, we have employed subcellular fractionations and membrane flotation assays to demonstrate that NS2 associates with detergent-resistant membranes (DRM) in a p7-dependent manner. However, p7 likely plays an indirect role in this process, since only the background level of p7 was detectable in the DRM fractions. Our data also suggest that the p7-NS2 precursor is not involved in NS2 recruitment to the DRM, despite its apparent targeting to this location. Deletion of NS2 specifically inhibited E2 localization to the DRM, indicating that NS2 regulates this process. Treatment of cells with methyl-β-cyclodextrin (MβCD) significantly reduced the DRM association of Core, NS2, and E2 and reduced infectious HCV production. Since disruption of the DRM localization of NS2 and E2, either due to p7 and NS2 defects, respectively, or by MβCD treatment, inhibited infectious HCV production, these proteins' associations with the DRM likely play an important role during HCV assembly. Interestingly, we detected the HCV replication-dependent accumulation of ApoE in the DRM fractions. Taking into consideration the facts that ApoE was shown to be a major determinant for infectious HCV particle production at the postenvelopment step and that the HCV Core protein strongly associates with the DRM, recruitment of E2 and ApoE to the DRM may allow the efficient coordination of Core particle envelopment and postenvelopment events at the DRM to generate infectious HCV production. The biochemical nature of HCV assembly sites is currently unknown. In this study, we investigated the correlation between NS2 and E2 localization to the detergent-resistant membranes (DRM) and HCV particle assembly. We determined that although NS2's DRM localization is dependent on p7, p7 was not targeted to these membranes. We then showed that NS2 regulates E2 localization to the DRM, consistent with its role in recruiting E2 to the virus assembly sites. We also showed that short-term treatment with the cholesterol-extracting agent methyl-β-cyclodextrin (MβCD) not only disrupted the DRM localization of Core, NS2, and E2 but also specifically inhibited intracellular virus assembly without affecting HCV RNA replication. Thus, our data support the role of the DRM as a platform for particle assembly process. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

A Higher Correlation of HCV Core Antigen with CD4+ T Cell Counts Compared with HCV RNA in HCV/HIV-1 Coinfected Patients

PubMed Central

Zhang, Weidong; Xi, Yuanlin; Cao, Guanghua; Zhi, Yuhong; Wang, Shuiwang; Xu, Chunhui; Wei, Lai; Lu, Fengmin; Zhuang, Hui

2011-01-01

Development of HCV infection is typically followed by chronic hepatitis C (CHC) in most patients, while spontaneous HCV viral clearance (SVC) occurs in only a minority of subjects. Compared with the widespread application of HCV RNA testing by quantitative RT-PCR technique, HCV core antigen detection may be an alternative indicator in the diagnosis of hepatitis C virus infections and in monitoring the status of infectious individuals. However, the correlation and differences between these two indicators in HCV infection need more investigation, especially in patients coinfected by HIV-1. In this study, a total of 354 anti-HCV and/or anti-HIV serum positive residents from a village of central China were enrolled. Besides HCV-related hepatopathic variables including clinical status, ALT, AST, anti-HCV Abs, as well as the altered CD4+/CD8+ T cell counts, HCV core antigen and HCV viral load were also measured. The concentration of serum HCV core antigen was highly correlated with level of HCV RNA in CHC patients with or without HIV-1 coinfection. Of note, HCV core antigen concentration was negatively correlated with CD4+ T cell count, while no correlation was found between HCV RNA level and CD4+ T cell count. Our findings suggested that quantitative detection of plasma HCV core antigen may be an alternative indicator of HCV RNA qPCR assay when evaluating the association between HCV replication and host immune status in HCV/HIV-1 coinfected patients. PMID:21858166

Analysis of hepatitis C virus RNA dimerization and core-RNA interactions.

PubMed

Ivanyi-Nagy, Roland; Kanevsky, Igor; Gabus, Caroline; Lavergne, Jean-Pierre; Ficheux, Damien; Penin, François; Fossé, Philippe; Darlix, Jean-Luc

2006-01-01

The core protein of hepatitis C virus (HCV) has been shown previously to act as a potent nucleic acid chaperone in vitro, promoting the dimerization of the 3'-untranslated region (3'-UTR) of the HCV genomic RNA, a process probably mediated by a small, highly conserved palindromic RNA motif, named DLS (dimer linkage sequence) [G. Cristofari, R. Ivanyi-Nagy, C. Gabus, S. Boulant, J. P. Lavergne, F. Penin and J. L. Darlix (2004) Nucleic Acids Res., 32, 2623-2631]. To investigate in depth HCV RNA dimerization, we generated a series of point mutations in the DLS region. We find that both the plus-strand 3'-UTR and the complementary minus-strand RNA can dimerize in the presence of core protein, while mutations in the DLS (among them a single point mutation that abolished RNA replication in a HCV subgenomic replicon system) completely abrogate dimerization. Structural probing of plus- and minus-strand RNAs, in their monomeric and dimeric forms, indicate that the DLS is the major if not the sole determinant of UTR RNA dimerization. Furthermore, the N-terminal basic amino acid clusters of core protein were found to be sufficient to induce dimerization, suggesting that they retain full RNA chaperone activity. These findings may have important consequences for understanding the HCV replicative cycle and the genetic variability of the virus.

Flunarizine Prevents Hepatitis C Virus Membrane Fusion in a Genotype-dependent Manner by Targeting the Potential Fusion Peptide within E1

PubMed Central

Perin, Paula M.; Haid, Sibylle; Brown, Richard J. P.; Doerrbecker, Juliane; Schulze, Kai; Zeilinger, Carsten; von Schaewen, Markus; Heller, Brigitte; Vercauteren, Koen; Luxenburger, Eva; Baktash, Yasmine M.; Vondran, Florian W. R.; Speerstra, Sietkse; Awadh, Abdullah; Mukhtarov, Furkat; Schang, Luis M; Kirschning, Andreas; Müller, Rolf; Guzman, Carlos A.; Kaderali, Lars; Randall, Glenn; Meuleman, Philip; Ploss, Alexander; Pietschmann, Thomas

2015-01-01

To explore mechanisms of hepatitis C virus (HCV) replication we screened a compound library including licensed drugs. Flunarizine, a diphenylmethylpiperazine used to treat migraine, inhibited HCV cell entry in vitro and in vivo in a genotype-dependent fashion. Analysis of mosaic viruses between susceptible and resistant strains revealed that E1 and E2 glycoproteins confer susceptibility to flunarizine. Time of addition experiments and single particle tracking of HCV demonstrated that flunarizine specifically prevents membrane fusion. Related phenothiazines and pimozide also inhibited HCV infection and preferentially targeted HCV genotype 2 viruses. However, phenothiazines and pimozide exhibited improved genotype coverage including the difficult to treat genotype 3. Flunarizine-resistant HCV carried mutations within the alleged fusion peptide and displayed cross-resistance to these compounds, indicating that these drugs have a common mode of action. Conclusion: These observations reveal novel details about HCV membrane fusion. Moreover, flunarizine and related compounds represent first-in-class HCV fusion inhibitors that merit consideration for repurposing as cost-effective component of HCV combination therapies. PMID:26248546

Hepatitis C virus resistance to broadly neutralizing antibodies measured using replication-competent virus and pseudoparticles

PubMed Central

Wasilewski, Lisa N.; Ray, Stuart C.

2016-01-01

A better understanding of natural variation in neutralization resistance and fitness of diverse hepatitis C virus (HCV) envelope (E1E2) variants will be critical to guide rational development of an HCV vaccine. This work has been hindered by inadequate genetic diversity in viral panels and by a lack of standardization of HCV entry assays. Neutralization assays generally use lentiviral pseudoparticles expressing HCV envelope proteins (HCVpp) or chimeric full-length viruses that are replication competent in cell culture (HCVcc). There have been few systematic comparisons of specific infectivities of E1E2-matched HCVcc and HCVpp, and to our knowledge, neutralization of E1E2-matched HCVpp and HCVcc has never been compared using a diverse panel of human broadly neutralizing monoclonal antibodies (bNAbs) targeting distinct epitopes. Here, we describe an efficient method for introduction of naturally occurring E1E2 genes into a full-length HCV genome, producing replication-competent chimeric HCVcc. We generated diverse panels of E1E2-matched HCVcc and HCVpp and measured the entry-mediating fitness of E1E2 variants using the two systems. We also compared neutralization of E1E2-matched HCVcc and HCVpp by a diverse panel of human bNAbs targeting epitopes across E1E2. We found no correlation between specific infectivities of E1E2-matched HCVcc versus HCVpp, but found a very strong positive correlation between relative neutralization resistance of these same E1E2-matched HCVcc and HCVpp variants. These results suggest that quantitative comparisons of neutralization resistance of E1E2 variants can be made with confidence using either HCVcc or HCVpp, allowing the use of either or both systems to maximize diversity of neutralization panels. PMID:27667373

Evasion of superinfection exclusion and elimination of primary viral RNA by an adapted strain of hepatitis C virus.

PubMed

Webster, Brian; Ott, Melanie; Greene, Warner C

2013-12-01

Cells that are productively infected by hepatitis C virus (HCV) are refractory to a second infection by HCV via a block in viral replication known as superinfection exclusion. The block occurs at a postentry step and likely involves translation or replication of the secondary viral RNA, but the mechanism is largely unknown. To characterize HCV superinfection exclusion, we selected for an HCV variant that could overcome the block. We produced a high-titer HC-J6/JFH1 (Jc1) viral genome with a fluorescent reporter inserted between NS5A and NS5B and used it to infect Huh7.5 cells containing a Jc1 replicon. With multiple passages of these infected cells, we isolated an HCV variant that can superinfect cells at high levels. Notably, the superinfectious virus rapidly cleared the primary replicon from superinfected cells. Viral competition experiments, using a novel strategy of sequence-barcoding viral strains, as well as superinfection of replicon cells demonstrated that mutations in E1, p7, NS5A, and the poly(U/UC) tract of the 3' untranslated region were important for superinfection. Furthermore, these mutations dramatically increased the infectivity of the virus in naive cells. Interestingly, viruses with a shorter poly(U/UC) and an NS5A domain II mutation were most effective in overcoming the postentry block. Neither of these changes affected viral RNA translation, indicating that the major barrier to postentry exclusion occurs at viral RNA replication. The evolution of the ability to superinfect after less than a month in culture and the concomitant exclusion of the primary replicon suggest that superinfection exclusion dramatically affects viral fitness and dynamics in vivo.

Hepatitis C virus resistance to broadly neutralizing antibodies measured using replication-competent virus and pseudoparticles.

PubMed

Wasilewski, Lisa N; Ray, Stuart C; Bailey, Justin R

2016-11-01

A better understanding of natural variation in neutralization resistance and fitness of diverse hepatitis C virus (HCV) envelope (E1E2) variants will be critical to guide rational development of an HCV vaccine. This work has been hindered by inadequate genetic diversity in viral panels and by a lack of standardization of HCV entry assays. Neutralization assays generally use lentiviral pseudoparticles expressing HCV envelope proteins (HCVpp) or chimeric full-length viruses that are replication competent in cell culture (HCVcc). There have been few systematic comparisons of specific infectivities of E1E2-matched HCVcc and HCVpp, and to our knowledge, neutralization of E1E2-matched HCVpp and HCVcc has never been compared using a diverse panel of human broadly neutralizing monoclonal antibodies (bNAbs) targeting distinct epitopes. Here, we describe an efficient method for introduction of naturally occurring E1E2 genes into a full-length HCV genome, producing replication-competent chimeric HCVcc. We generated diverse panels of E1E2-matched HCVcc and HCVpp and measured the entry-mediating fitness of E1E2 variants using the two systems. We also compared neutralization of E1E2-matched HCVcc and HCVpp by a diverse panel of human bNAbs targeting epitopes across E1E2. We found no correlation between specific infectivities of E1E2-matched HCVcc versus HCVpp, but found a very strong positive correlation between relative neutralization resistance of these same E1E2-matched HCVcc and HCVpp variants. These results suggest that quantitative comparisons of neutralization resistance of E1E2 variants can be made with confidence using either HCVcc or HCVpp, allowing the use of either or both systems to maximize diversity of neutralization panels.

Oncolytic reovirus as a combined antiviral and anti-tumour agent for the treatment of liver cancer.

PubMed

Samson, Adel; Bentham, Matthew J; Scott, Karen; Nuovo, Gerard; Bloy, Abigail; Appleton, Elizabeth; Adair, Robert A; Dave, Rajiv; Peckham-Cooper, Adam; Toogood, Giles; Nagamori, Seishi; Coffey, Matthew; Vile, Richard; Harrington, Kevin; Selby, Peter; Errington-Mais, Fiona; Melcher, Alan; Griffin, Stephen

2018-03-01

Oncolytic viruses (OVs) represent promising, proinflammatory cancer treatments. Here, we explored whether OV-induced innate immune responses could simultaneously inhibit HCV while suppressing hepatocellular carcinoma (HCC). Furthermore, we extended this exemplar to other models of virus-associated cancer. Clinical grade oncolytic orthoreovirus (Reo) elicited innate immune activation within primary human liver tissue in the absence of cytotoxicity and independently of viral genome replication. As well as achieving therapy in preclinical models of HCC through the activation of innate degranulating immune cells, Reo-induced cytokine responses efficiently suppressed HCV replication both in vitro and in vivo. Furthermore, Reo-induced innate responses were also effective against models of HBV-associated HCC, as well as an alternative endogenous model of Epstein-Barr virus-associated lymphoma. Interestingly, Reo appeared superior to the majority of OVs in its ability to elicit innate inflammatory responses from primary liver tissue. We propose that Reo and other select proinflammatory OV may be used in the treatment of multiple cancers associated with oncogenic virus infections, simultaneously reducing both virus-associated oncogenic drive and tumour burden. In the case of HCV-associated HCC (HCV-HCC), Reo should be considered as an alternative agent to supplement and support current HCV-HCC therapies, particularly in those countries where access to new HCV antiviral treatments may be limited. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Inducing Hepatitis C Virus Resistance After Pig Liver Transplantation-A Proof of Concept of Liver Graft Modification Using Warm Ex Vivo Perfusion.

PubMed

Goldaracena, N; Spetzler, V N; Echeverri, J; Kaths, J M; Cherepanov, V; Persson, R; Hodges, M R; Janssen, H L A; Selzner, N; Grant, D R; Feld, J J; Selzner, M

2017-04-01

Normothermic ex vivo liver perfusion (NEVLP) offers the potential to optimize graft function prior to liver transplantation (LT). Hepatitis C virus (HCV) is dependent on the presence of miRNA(microRNA)-122. Miravirsen, a locked-nucleic acid oligonucleotide, sequesters miR-122 and inhibits HCV replication. The aim of this study was to assess the efficacy of delivering miravirsen during NEVLP to inhibit miR-122 function in a pig LT model. Pig livers were treated with miravirsen during NEVLP or cold storage (CS). Miravirsen absorption, miR-122 sequestration, and miR-122 target gene derepression were determined before and after LT. The effect of miravirsen treatment on HCV infection of hepatoma cells was also assessed. NEVLP improved miravirsen uptake versus CS. Significant miR-122 sequestration and miR-122 target gene derepression were seen with NEVLP but not with CS. In vitro data confirmed miravirsen suppression of HCV replication after established infection and prevented HCV infection with pretreatment of cells, analogous to the pretreatment of grafts in the transplant setting. In conclusion, miravirsen delivery during NEVLP is a potential strategy to prevent HCV reinfection after LT. This is the first large-animal study to provide "proof of concept" for using NEVLP to modify and optimize liver grafts for transplantation. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Hepatitis C Virus: Viral Quasispecies and Genotypes.

PubMed

Tsukiyama-Kohara, Kyoko; Kohara, Michinori

2017-12-22

Hepatitis C virus (HCV) mainly replicates in the cytoplasm, where it easily establishes persistent infection, resulting in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Due to its high rate of mutation, HCV forms viral quasispecies, categorized based on the highly variable regions in the envelope protein and nonstructural 5A protein. HCV possesses seven major genotypes, among which genotype 1 is the most prevalent globally. The distribution of HCV genotypes varies based on geography, and each genotype has a different sensitivity to interferon treatment. Recently-developed direct-acting antivirals (DAAs), which target viral proteases or polymerases, mediate drastically better antiviral effects than previous therapeutics. Although treatment with DAAs has led to the development of drug-resistant HCV mutants, the most recently approved DAAs show improved pan-genomic activity, with a higher barrier to viral resistance.

Inhibitor-induced structural change in the HCV IRES domain IIa RNA

PubMed Central

Paulsen, Ryan B.; Seth, Punit P.; Swayze, Eric E.; Griffey, Richard H.; Skalicky, Jack J.; Cheatham, Thomas E.; Davis, Darrell R.

2010-01-01

Translation of the hepatitis C virus (HCV) RNA is initiated from a highly structured internal ribosomal entry site (IRES) in the 5′ untranslated region (5′ UTR) of the RNA genome. An important structural feature of the native RNA is an approximately 90° helical bend localized to domain IIa that positions the apical loop of domain IIb of the IRES near the 40S ribosomal E-site to promote eIF2-GDP release, facilitating 80S ribosome assembly. We report here the NMR structure of a domain IIa construct in complex with a potent small-molecule inhibitor of HCV replication. Molecular dynamics refinement in explicit solvent and subsequent energetic analysis indicated that each inhibitor stereoisomer bound with comparable affinity and in an equivalent binding mode. The in silico analysis was substantiated by fluorescence-based assays showing that the relative binding free energies differed by only 0.7 kcal/mol. Binding of the inhibitor displaces key nucleotide residues within the bulge region, effecting a major conformational change that eliminates the bent RNA helical trajectory, providing a mechanism for the antiviral activity of this inhibitor class. PMID:20360559

Hepatitis C virus (HCV) induces formation of stress granules whose proteins regulate HCV RNA replication and virus assembly and egress.

PubMed

Garaigorta, Urtzi; Heim, Markus H; Boyd, Bryan; Wieland, Stefan; Chisari, Francis V

2012-10-01

Stress granules (SGs) are cytoplasmic structures that are induced in response to environmental stress, including viral infections. Here we report that hepatitis C virus (HCV) triggers the appearance of SGs in a PKR- and interferon (IFN)-dependent manner. Moreover, we show an inverse correlation between the presence of stress granules and the induction of IFN-stimulated proteins, i.e., MxA and USP18, in HCV-infected cells despite high-level expression of the corresponding MxA and USP18 mRNAs, suggesting that interferon-stimulated gene translation is inhibited in stress granule-containing HCV-infected cells. Finally, in short hairpin RNA (shRNA) knockdown experiments, we found that the stress granule proteins T-cell-restricted intracellular antigen 1 (TIA-1), TIA1-related protein (TIAR), and RasGAP-SH3 domain binding protein 1 (G3BP1) are required for efficient HCV RNA and protein accumulation at early time points in the infection and that G3BP1 and TIA-1 are required for intracellular and extracellular infectious virus production late in the infection, suggesting that they are required for virus assembly. In contrast, TIAR downregulation decreases extracellular infectious virus titers with little effect on intracellular RNA content or infectivity late in the infection, suggesting that it is required for infectious particle release. Collectively, these results illustrate that HCV exploits the stress granule machinery at least two ways: by inducing the formation of SGs by triggering PKR phosphorylation, thereby downregulating the translation of antiviral interferon-stimulated genes, and by co-opting SG proteins for its replication, assembly, and egress.

Effect of Quercetin on Hepatitis C Virus Life Cycle: From Viral to Host Targets.

PubMed

Rojas, Ángela; Del Campo, Jose A; Clement, Sophie; Lemasson, Matthieu; García-Valdecasas, Marta; Gil-Gómez, Antonio; Ranchal, Isidora; Bartosch, Birke; Bautista, Juan D; Rosenberg, Arielle R; Negro, Francesco; Romero-Gómez, Manuel

2016-08-22

Quercetin is a natural flavonoid, which has been shown to have anti hepatitis C virus (HCV) properties. However, the exact mechanisms whereby quercetin impacts the HCV life cycle are not fully understood. We assessed the effect of quercetin on different steps of the HCV life cycle in Huh-7.5 cells and primary human hepatocytes (PHH) infected with HCVcc. In both cell types, quercetin significantly decreased i) the viral genome replication; ii) the production of infectious HCV particles and iii) the specific infectivity of the newly produced viral particles (by 85% and 92%, Huh7.5 and PHH respectively). In addition, when applied directly on HCV particles, quercetin reduced their infectivity by 65%, suggesting that it affects the virion integrity. Interestingly, the HCV-induced up-regulation of diacylglycerol acyltransferase (DGAT) and the typical localization of the HCV core protein to the surface of lipid droplets, known to be mediated by DGAT, were both prevented by quercetin. In conclusion, quercetin appears to have direct and host-mediated antiviral effects against HCV.

Effect of Quercetin on Hepatitis C Virus Life Cycle: From Viral to Host Targets

PubMed Central

Rojas, Ángela; Del Campo, Jose A.; Clement, Sophie; Lemasson, Matthieu; García-Valdecasas, Marta; Gil-Gómez, Antonio; Ranchal, Isidora; Bartosch, Birke; Bautista, Juan D.; Rosenberg, Arielle R.; Negro, Francesco; Romero-Gómez, Manuel

2016-01-01

Quercetin is a natural flavonoid, which has been shown to have anti hepatitis C virus (HCV) properties. However, the exact mechanisms whereby quercetin impacts the HCV life cycle are not fully understood. We assessed the effect of quercetin on different steps of the HCV life cycle in Huh-7.5 cells and primary human hepatocytes (PHH) infected with HCVcc. In both cell types, quercetin significantly decreased i) the viral genome replication; ii) the production of infectious HCV particles and iii) the specific infectivity of the newly produced viral particles (by 85% and 92%, Huh7.5 and PHH respectively). In addition, when applied directly on HCV particles, quercetin reduced their infectivity by 65%, suggesting that it affects the virion integrity. Interestingly, the HCV-induced up-regulation of diacylglycerol acyltransferase (DGAT) and the typical localization of the HCV core protein to the surface of lipid droplets, known to be mediated by DGAT, were both prevented by quercetin. In conclusion, quercetin appears to have direct and host-mediated antiviral effects against HCV. PMID:27546480

HCV versus HIV drug discovery: Déjà vu all over again?

PubMed

Watkins, William J; Desai, Manoj C

2013-04-15

Efforts to address HIV infection have been highly successful, enabling chronic suppression of viral replication with once-daily regimens. More recent research into HCV therapeutics have also resulted in very promising clinical candidates. This Digest explores similarities and differences in the two fields and compares the chronology of drug discovery relative to the availability of enabling tools, and concludes that safe and convenient, once-daily regimens are likely to reach approval much more rapidly for HCV than was the case for HIV. Copyright © 2013 Elsevier Ltd. All rights reserved.

End-to-end crosstalk within the hepatitis C virus genome mediates the conformational switch of the 3′X-tail region

PubMed Central

Romero-López, Cristina; Barroso-delJesus, Alicia; García-Sacristán, Ana; Briones, Carlos; Berzal-Herranz, Alfredo

2014-01-01

The hepatitis C virus (HCV) RNA genome contains multiple structurally conserved domains that make long-distance RNA–RNA contacts important in the establishment of viral infection. Microarray antisense oligonucelotide assays, improved dimethyl sulfate probing methods and 2′ acylation chemistry (selective 2’-hydroxyl acylation and primer extension, SHAPE) showed the folding of the genomic RNA 3′ end to be regulated by the internal ribosome entry site (IRES) element via direct RNA–RNA interactions. The essential cis-acting replicating element (CRE) and the 3′X-tail region adopted different 3D conformations in the presence and absence of the genomic RNA 5′ terminus. Further, the structural transition in the 3′X-tail from the replication-competent conformer (consisting of three stem-loops) to the dimerizable form (with two stem-loops), was found to depend on the presence of both the IRES and the CRE elements. Complex interplay between the IRES, the CRE and the 3′X-tail region would therefore appear to occur. The preservation of this RNA–RNA interacting network, and the maintenance of the proper balance between different contacts, may play a crucial role in the switch between different steps of the HCV cycle. PMID:24049069

Analysis of hepatitis C virus RNA dimerization and core–RNA interactions

PubMed Central

Ivanyi-Nagy, Roland; Kanevsky, Igor; Gabus, Caroline; Lavergne, Jean-Pierre; Ficheux, Damien; Penin, François; Fossé, Philippe; Darlix, Jean-Luc

2006-01-01

The core protein of hepatitis C virus (HCV) has been shown previously to act as a potent nucleic acid chaperone in vitro, promoting the dimerization of the 3′-untranslated region (3′-UTR) of the HCV genomic RNA, a process probably mediated by a small, highly conserved palindromic RNA motif, named DLS (dimer linkage sequence) [G. Cristofari, R. Ivanyi-Nagy, C. Gabus, S. Boulant, J. P. Lavergne, F. Penin and J. L. Darlix (2004) Nucleic Acids Res., 32, 2623–2631]. To investigate in depth HCV RNA dimerization, we generated a series of point mutations in the DLS region. We find that both the plus-strand 3′-UTR and the complementary minus-strand RNA can dimerize in the presence of core protein, while mutations in the DLS (among them a single point mutation that abolished RNA replication in a HCV subgenomic replicon system) completely abrogate dimerization. Structural probing of plus- and minus-strand RNAs, in their monomeric and dimeric forms, indicate that the DLS is the major if not the sole determinant of UTR RNA dimerization. Furthermore, the N-terminal basic amino acid clusters of core protein were found to be sufficient to induce dimerization, suggesting that they retain full RNA chaperone activity. These findings may have important consequences for understanding the HCV replicative cycle and the genetic variability of the virus. PMID:16707664

Increased Phosphoenolpyruvate Carboxykinase (PEPCK) Gene Expression and Steatosis During Hepatitis C Virus (HCV) Subgenome Replication: Role of Nonstructural Component-5A (NS5A) and CCAAT/Enhancer Binding Protein ß (C/EBPß)

USDA-ARS?s Scientific Manuscript database

Chronic hepatitis C virus (HCV) infection greatly increases the risk for type 2 diabetes and nonalcoholic steatohepatitis; however, the pathogenic mechanisms remain incompletely understood. Here we report gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) transcription and associated tra...

An overview of triple infection with hepatitis B, C and D viruses.

PubMed

Riaz, Mehwish; Idrees, Muhamad; Kanwal, Hifza; Kabir, Firoz

2011-07-27

Viral hepatitis is one of the major health problems worldwide, particularly in South East Asian countries including Pakistan where hepatitis C virus (HCV) and hepatitis B virus (HBV) infections are highly endemic. Hepatitis delta virus (HDV) is also not uncommon world-wide. HCV, HBV, and HDV share parallel routes of transmission due to which dual or triple viral infection can occur in a proportion of patients at the same time. HBV and HCV are important factors in the development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). In addition to LC and HCC, chronic HDV infection also plays an important role in liver damage with oncogenic potential.The current article reviews the available literature about the epidemiology, pathogenesis, transmission, symptoms, diagnosis, replication, disease outcome, treatment and preventive measures of triple hepatitis infection by using key words; epidemiology of triple infection, risk factors, awareness status, treatment and replication cycle in PubMed, PakMediNet, Directory of Open Access Journals (DOAJ) and Google Scholar. Total data from 74 different studies published from 1983 to 2010 on triple hepatitis infections were reviewed and included in this study. The present article briefly describes triple infection with HCV, HBV and HDV.

Hepatitis C virus and antiviral innate immunity: who wins at tug-of-war?

PubMed

Yang, Da-Rong; Zhu, Hai-Zhen

2015-04-07

Hepatitis C virus (HCV) is a major human pathogen of chronic hepatitis and related liver diseases. Innate immunity is the first line of defense against invading foreign pathogens, and its activation is dependent on the recognition of these pathogens by several key sensors. The interferon (IFN) system plays an essential role in the restriction of HCV infection via the induction of hundreds of IFN-stimulated genes (ISGs) that inhibit viral replication and spread. However, numerous factors that trigger immune dysregulation, including viral factors and host genetic factors, can help HCV to escape host immune response, facilitating viral persistence. In this review, we aim to summarize recent advances in understanding the innate immune response to HCV infection and the mechanisms of ISGs to suppress viral survival, as well as the immune evasion strategies for chronic HCV infection.

Hepatitis C Virus: Viral Quasispecies and Genotypes

PubMed Central

Tsukiyama-Kohara, Kyoko; Kohara, Michinori

2017-01-01

Hepatitis C virus (HCV) mainly replicates in the cytoplasm, where it easily establishes persistent infection, resulting in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Due to its high rate of mutation, HCV forms viral quasispecies, categorized based on the highly variable regions in the envelope protein and nonstructural 5A protein. HCV possesses seven major genotypes, among which genotype 1 is the most prevalent globally. The distribution of HCV genotypes varies based on geography, and each genotype has a different sensitivity to interferon treatment. Recently-developed direct-acting antivirals (DAAs), which target viral proteases or polymerases, mediate drastically better antiviral effects than previous therapeutics. Although treatment with DAAs has led to the development of drug-resistant HCV mutants, the most recently approved DAAs show improved pan-genomic activity, with a higher barrier to viral resistance. PMID:29271914

A primer on the molecular virology of hepatitis C.

PubMed

Moradpour, Darius; Blum, Hubert E

2004-12-01

Exciting advances have recently been made in the understanding of the molecular virology of hepatitis C. Powerful model systems have been developed that allow to systematically dissect important steps of the hepatitis C virus (HCV) life cycle. These include new systems for functional analyses of the HCV glycoproteins, providing insights into possible HCV receptors and cell entry mechanisms, and the replicon system, which has revolutionized investigation of HCV RNA replication and has facilitated drug discovery efforts. The largest gaps remain in the understanding of the virion structure and the processes that lead to the assembly, packaging and release of virions. However, given the pace of current HCV research, progress in these directions may be expected in the near future. Here, we provide a primer on the molecular virology of hepatitis C, with particular reference to novel antiviral targets and therapeutic strategies.

Persistence of Circulating Hepatitis C Virus Antigens-Specific Immune Complexes in Patients with Resolved HCV Infection.

PubMed

Hu, Ke-Qin; Cui, Wei

2018-05-01

Our recent study indicated the possible presence of detectable hepatitis C virus antigens (HCV-Ags) after denaturation of sera with resolved HCV (R-HCV) infection. The present study determined and characterized persistent HCV-Ags-specific immune complexes (ICs) in these patients. Sixty-eight sera with R-HCV and 34 with viremic HCV (V-HCV) infection were tested for free and IC-bound HCV-Ags using HCV-Ags enzyme immunoassay (EIA), the presence of HCV-Ags-specific ICs by immunoprecipitation and Western blot (IP-WB), HCV ICs containing HCV virions using IP and HCV RNA RT-PCR, and correlation of HCV ICs with clinical presentation in these patients. Using HCV-Ags EIA, we found 57.4% of sera with R-HCV infection were tested positive for bound, but not free HCV-Ags. Using pooled or individual anti-HCV E1/E2, cAg, NS3, NS4b, and/or NS5a to precipitate HCV-specific-Ags, we confirmed persistent HCV-Ags ICs specific to various HCV structural and non-structural proteins not only in V-HCV infection, but also in R-HCV infection. Using IP and HCV RNA PCR, we then confirmed the presence of HCV virions within circulating ICs in V-HCV, but not in R-HCV sera. Multivariable analysis indicated significant and independent associations of persistent circulating HCV-Ags-specific ICs with both age and the presence of cirrhosis in patients with R-HCV infection. Various HCV-Ag-specific ICs, but not virions, persist in 57.4% of patients who had spontaneous or treatment-induced HCV clearance for 6 months to 20 years. These findings enriched our knowledge on HCV pathogenesis and support further study on its long-term clinical relevance, such as extrahepatic manifestation, transfusion medicine, and hepatocarcinogenesis.

Identification and Targeting of an Interaction between a Tyrosine Motif within Hepatitis C Virus Core Protein and AP2M1 Essential for Viral Assembly

PubMed Central

Ziv-Av, Amotz; Gerber, Doron; Jacob, Yves; Einav, Shirit

2012-01-01

Novel therapies are urgently needed against hepatitis C virus infection (HCV), a major global health problem. The current model of infectious virus production suggests that HCV virions are assembled on or near the surface of lipid droplets, acquire their envelope at the ER, and egress through the secretory pathway. The mechanisms of HCV assembly and particularly the role of viral-host protein-protein interactions in mediating this process are, however, poorly understood. We identified a conserved heretofore unrecognized YXXΦ motif (Φ is a bulky hydrophobic residue) within the core protein. This motif is homologous to sorting signals within host cargo proteins known to mediate binding of AP2M1, the μ subunit of clathrin adaptor protein complex 2 (AP-2), and intracellular trafficking. Using microfluidics affinity analysis, protein-fragment complementation assays, and co-immunoprecipitations in infected cells, we show that this motif mediates core binding to AP2M1. YXXΦ mutations, silencing AP2M1 expression or overexpressing a dominant negative AP2M1 mutant had no effect on HCV RNA replication, however, they dramatically inhibited intra- and extracellular infectivity, consistent with a defect in viral assembly. Quantitative confocal immunofluorescence analysis revealed that core's YXXΦ motif mediates recruitment of AP2M1 to lipid droplets and that the observed defect in HCV assembly following disruption of core-AP2M1 binding correlates with accumulation of core on lipid droplets, reduced core colocalization with E2 and reduced core localization to trans-Golgi network (TGN), the presumed site of viral particles maturation. Furthermore, AAK1 and GAK, serine/threonine kinases known to stimulate binding of AP2M1 to host cargo proteins, regulate core-AP2M1 binding and are essential for HCV assembly. Last, approved anti-cancer drugs that inhibit AAK1 or GAK not only disrupt core-AP2M1 binding, but also significantly inhibit HCV assembly and infectious virus production. These results validate viral-host interactions essential for HCV assembly and yield compounds for pharmaceutical development. PMID:22916011

Packaging of HCV-RNA into lentiviral vector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caval, Vincent; Piver, Eric; Service de Biochimie et Biologie Moleculaire, CHRU de Tours

2011-11-04

Highlights: Black-Right-Pointing-Pointer Description of HCV-RNA Core-D1 interactions. Black-Right-Pointing-Pointer In vivo evaluation of the packaging of HCV genome. Black-Right-Pointing-Pointer Determination of the role of the three basic sub-domains of D1. Black-Right-Pointing-Pointer Heterologous system involving HIV-1 vector particles to mobilise HCV genome. Black-Right-Pointing-Pointer Full length mobilisation of HCV genome and HCV-receptor-independent entry. -- Abstract: The advent of infectious molecular clones of Hepatitis C virus (HCV) has unlocked the understanding of HCV life cycle. However, packaging of the genomic RNA, which is crucial to generate infectious viral particles, remains poorly understood. Molecular interactions of the domain 1 (D1) of HCV Core protein andmore » HCV RNA have been described in vitro. Since compaction of genetic information within HCV genome has hampered conventional mutational approach to study packaging in vivo, we developed a novel heterologous system to evaluate the interactions between HCV RNA and Core D1. For this, we took advantage of the recruitment of Vpr fusion-proteins into HIV-1 particles. By fusing HCV Core D1 to Vpr we were able to package and transfer a HCV subgenomic replicon into a HIV-1 based lentiviral vector. We next examined how deletion mutants of basic sub-domains of Core D1 influenced HCV RNA recruitment. The results emphasized the crucial role of the first and third basic regions of D1 in packaging. Interestingly, the system described here allowed us to mobilise full-length JFH1 genome in CD81 defective cells, which are normally refractory to HCV infection. This finding paves the way to an evaluation of the replication capability of HCV in various cell types.« less

The role of pharmacogenetics in the treatment of chronic hepatitis C infection.

PubMed

Kawaguchi-Suzuki, Marina; Frye, Reginald F

2014-02-01

Hepatitis C virus (HCV) chronically infects 170 million people worldwide. Until recently, combination therapy with peginterferon-α (pegIFN) and ribavirin (RBV) has been the standard of care. However, for many patients, especially those infected with the most common HCV genotype 1 (HCV-1), this treatment has resulted in unsatisfactory treatment response rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. Genetic variation in the interleukin 28B (IL28B) gene is the major determinant of treatment response, a finding that has been replicated in multiple independent cohorts. This review focuses on the association between pharmacogenetics and conventional pegIFN/RBV therapy in patients infected with HCV non-genotype 1; patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. We also review the pharmacogenetic data for boceprevir and telaprevir triple therapy in patients with HCV-1 infection, as well as viral genomic polymorphisms and genetic variants that may protect against anemia. Pharmacogenetic information offers a personalized medicine approach to help clinicians and patients make better informed decisions to maximize response and minimize toxicity for the treatment of chronic HCV infection. © 2013 Pharmacotherapy Publications, Inc.

Antioxidant and Anti-Hepatitis C Viral Activities of Commercial Milk Thistle Food Supplements

PubMed Central

Anthony, Kevin; Subramanya, Gitanjali; Uprichard, Susan; Hammouda, Faiza; Saleh, Mahmoud

2013-01-01

Milk thistle dietary supplements that contain silymarin are widely marketed and used in the USA and other countries for liver enhancement and recovery. More recently, silymarin has also been identified as a possible antiviral for the treatment of hepatitis C virus (HCV) infection. To assess different brands of commercially sold silymarin, 45 products were collected from local stores and analyzed for their silymarin content, antioxidant activities, and antiviral activity against HCV. Antioxidant activity was measured as radical scavenging activity using DPPH and by estimating their antioxidant capacity as trolox equivalent. Anti-HCV activity was measured in an HCV genotype 1b replication inhibition assay. Samples were found to vary widely in their silymarin content, with some samples having none or very low concentrations while silymarin represented higher than 80% of other samples. Both antioxidant and anti-HCV activity correlated with the overall level of silymarin. PMID:26787620

Advances with using CRISPR/Cas-mediated gene editing to treat infections with hepatitis B virus and hepatitis C virus.

PubMed

Moyo, Buhle; Bloom, Kristie; Scott, Tristan; Ely, Abdullah; Arbuthnot, Patrick

2018-01-15

Chronic infections with hepatitis B and hepatitis C viruses (HBV and HCV) account for the majority of cases of cirrhosis and hepatocellular carcinoma. Current therapies for the infections have limitations and improved efficacy is necessary to prevent complications in carriers of the viruses. In the case of HBV persistence, the replication intermediate comprising covalently closed circular DNA (cccDNA) is particularly problematic. Licensed therapies have little effect on cccDNA and HBV replication relapses following treatment withdrawal. Disabling cccDNA is thus key to curing HBV infections and application of gene editing technology, such as harnessing the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system, has curative potential. Several studies have reported good efficacy when employing CRISPR/Cas technologies to disable HBV replication in cultured cells and in hydrodynamically injected mice. Recent advances with HCV drug development have revolutionized treatment of the infection. Nevertheless, individuals may be refractory to treatment. Targeting RNA from HCV with CRISPR/Cas isolated from Francisella novicida may have therapeutic utility. Although preclinical work shows that CRISPR/Cas technology has potential to overcome infection with HBV and HCV, significant challenges need to be met. Ensuring specificity for viral targets and efficient delivery of the gene editing sequences to virus-infected cells are particularly important. The field is at an interesting stage and the future of curative antiviral drug regimens, particularly for treatment of chronic HBV infection, may well entail use of combinations that include derivatives of CRISPR/Cas. Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment of Chronic Hepatitis C in the Aged - Does It Impact Life Expectancy? A Decision Analysis.

PubMed

Maor, Yaakov; Malnick, Stephen D H; Melzer, Ehud; Leshno, Moshe

2016-01-01

Recent studies have demonstrated that the efficacy of interferon-free direct-acting antiviral agents (DAAs) in patients over 70 is similar to that of younger age groups. Evidence continues to mount that life expectancy (LE) increases with successful treatment of hepatitis C (HCV) patients with advanced fibrosis. The evidence in older people is more limited. Our aim was to estimate the life year (LY) and quality-adjusted life year (QALY) gained by treatment of naïve patients with HCV as a function of patient's age and fibrosis stage. We constructed a Markov model of HCV progression toward advanced liver disease. The primary outcome was LY and QALY saved. The model and the sustained virological response of HCV infected subjects treated with a fixed-dose combination of the NS5B polymerase inhibitor Sofosbuvir and the NS5A replication complex inhibitor Ledipasvir were based on the published literature and expert opinion. Generally, both the number of LY gained and QALY gained gradually decreased with advancing age but the rate of decline was slower with more advanced fibrosis stage. For patients with fibrosis stage F1, F2 and F3, LY gained dropped below six months if treated by the age of 55, 65 or 70 years, respectively, while for a patient with fibrosis stage F4, the gain was one LY if treated by the age of 75. The QALY gained for treated over untreated elderly were reasonably high even for those treated at early fibrosis stage. There is a significant life expectancy benefit to HCV treatment in patients up to age 75 with advanced-stage fibrosis.

Treatment of Chronic Hepatitis C in the Aged – Does It Impact Life Expectancy? A Decision Analysis

PubMed Central

Maor, Yaakov; Malnick, Stephen D. H.; Melzer, Ehud; Leshno, Moshe

2016-01-01

Background and Aims Recent studies have demonstrated that the efficacy of interferon-free direct-acting antiviral agents (DAAs) in patients over 70 is similar to that of younger age groups. Evidence continues to mount that life expectancy (LE) increases with successful treatment of hepatitis C (HCV) patients with advanced fibrosis. The evidence in older people is more limited. Our aim was to estimate the life year (LY) and quality-adjusted life year (QALY) gained by treatment of naïve patients with HCV as a function of patient's age and fibrosis stage. Methods We constructed a Markov model of HCV progression toward advanced liver disease. The primary outcome was LY and QALY saved. The model and the sustained virological response of HCV infected subjects treated with a fixed-dose combination of the NS5B polymerase inhibitor Sofosbuvir and the NS5A replication complex inhibitor Ledipasvir were based on the published literature and expert opinion. Results Generally, both the number of LY gained and QALY gained gradually decreased with advancing age but the rate of decline was slower with more advanced fibrosis stage. For patients with fibrosis stage F1, F2 and F3, LY gained dropped below six months if treated by the age of 55, 65 or 70 years, respectively, while for a patient with fibrosis stage F4, the gain was one LY if treated by the age of 75. The QALY gained for treated over untreated elderly were reasonably high even for those treated at early fibrosis stage. Conclusions There is a significant life expectancy benefit to HCV treatment in patients up to age 75 with advanced-stage fibrosis. PMID:27410963

Functional foods effective for hepatitis C: Identification of oligomeric proanthocyanidin and its action mechanism

PubMed Central

Ishida, Yo-ichi; Takeshita, Masahiko; Kataoka, Hiroaki

2014-01-01

Hepatitis C virus (HCV) is a major cause of viral hepatitis and currently infects approximately 170 million people worldwide. An infection by HCV causes high rates of chronic hepatitis (> 75%) and progresses to liver cirrhosis and hepatocellular carcinoma ultimately. HCV can be eliminated by a combination of pegylated α-interferon and the broad-spectrum antiviral drug ribavirin; however, this treatment is still associated with poor efficacy and tolerability and is often accompanied by serious side-effects. While some novel direct-acting antivirals against HCV have been developed recently, high medical costs limit the access to the therapy in cost-sensitive countries. To search for new natural anti-HCV agents, we screened local agricultural products for their suppressive activities against HCV replication using the HCV replicon cell system in vitro. We found a potent inhibitor of HCV RNA expression in the extracts of blueberry leaves and then identified oligomeric proanthocyanidin as the active ingredient. Further investigations into the action mechanism of oligomeric proanthocyanidin suggested that it is an inhibitor of heterogeneous nuclear ribonucleoproteins (hnRNPs) such as hnRNP A2/B1. In this review, we presented an overview of functional foods and ingredients efficient for HCV infection, the chemical structural characteristics of oligomeric proanthocyanidin, and its action mechanism. PMID:25544874

Chaperones in hepatitis C virus infection

PubMed Central

Khachatoorian, Ronik; French, Samuel W

2016-01-01

The hepatitis C virus (HCV) infects approximately 3% of the world population or more than 185 million people worldwide. Each year, an estimated 350000-500000 deaths occur worldwide due to HCV-associated diseases including cirrhosis and hepatocellular carcinoma. HCV is the most common indication for liver transplantation in patients with cirrhosis worldwide. HCV is an enveloped RNA virus classified in the genus Hepacivirus in the Flaviviridae family. The HCV viral life cycle in a cell can be divided into six phases: (1) binding and internalization; (2) cytoplasmic release and uncoating; (3) viral polyprotein translation and processing; (4) RNA genome replication; (5) encapsidation (packaging) and assembly; and (6) virus morphogenesis (maturation) and secretion. Many host factors are involved in the HCV life cycle. Chaperones are an important group of host cytoprotective molecules that coordinate numerous cellular processes including protein folding, multimeric protein assembly, protein trafficking, and protein degradation. All phases of the viral life cycle require chaperone activity and the interaction of viral proteins with chaperones. This review will present our current knowledge and understanding of the role of chaperones in the HCV life cycle. Analysis of chaperones in HCV infection will provide further insights into viral/host interactions and potential therapeutic targets for both HCV and other viruses. PMID:26783419

Multilaboratory comparison of hepatitis C virus viral load assays.

PubMed

Caliendo, A M; Valsamakis, A; Zhou, Y; Yen-Lieberman, B; Andersen, J; Young, S; Ferreira-Gonzalez, A; Tsongalis, G J; Pyles, R; Bremer, J W; Lurain, N S

2006-05-01

We report a multilaboratory evaluation of hepatitis C virus (HCV) viral load assays to determine their linear range, reproducibility, subtype detection, and agreement. A panel of HCV RNA samples ranging in nominal concentration from 1.0 to 7.0 log10 IU/ml was constructed by diluting a clinical specimen (genotype 1b). Replicates of the panel were tested in multiple laboratories using the Abbott TaqMan analyte-specific reagent (Abbott reverse transcription-PCR [RT-PCR]), Roche TaqMan RUO (Roche RT-PCR), Roche Amplicor Monitor HCV 2.0 (Roche Monitor), and Bayer VERSANT HCV RNA 3.0 (Bayer bDNA) assays. Bayer bDNA-negative specimens were tested reflexively using the Bayer VERSANT HCV RNA qualitative assay (Bayer TMA). Abbott RT-PCR and Roche RT-PCR detected all 28 replicates with a concentration of 1.0 log10 IU/ml and were linear to 7.0 log10 IU/ml. Roche Monitor and Bayer bDNA detected 27 out of 28 and 13 out of 28 replicates, respectively, of 3.0 log10 IU/ml. Bayer TMA detected all seven replicates with 1.0 log10 IU/ml. Bayer bDNA was the most reproducible of the four assays. The mean viral load values for panel members in the linear ranges of the assays were within 0.5 log10 for the different tests. Eighty-nine clinical specimens of various genotypes (1 through 4) were tested in the Bayer bDNA, Abbott RT-PCR, and Roche RT-PCR assays. For Abbott RT-PCR, mean viral load values were 0.61 to 0.96 log10 greater than the values for Bayer bDNA assay for samples with genotype 1, 2, or 3 samples and 0.08 log10 greater for genotype 4 specimens. The Roche RT-PCR assay gave mean viral load values that were 0.28 to 0.82 log10 greater than those obtained with the Bayer bDNA assay for genotype 1, 2, and 3 samples. However, for genotype 4 samples the mean viral load value obtained with the Roche RT-PCR assay was, on average, 0.15 log10 lower than that of the Bayer bDNA. Based on these data, we conclude that the sensitivity and linear range of the Abbott and Roche RT-PCR assays enable them to be used for HCV diagnostics and therapeutic monitoring. However, the differences in the viral load values obtained with the different assays underscore the importance of using one assay when monitoring response to therapy.

Liver transplantation from anti-hepatitis C virus-positive donors: our experience.

PubMed

Álvaro, E; Abradelo, M; Fuertes, A; Manrique, A; Colina, F; Alegre, C; Calvo, J; García, M; García-Sesma, A; Cambra, F; Sanabria, R; Moreno, E; Jimenez, C

2012-01-01

Hepatitis C (HCV) is among the most common causes of end-stage liver disease worldwide. The donor shortage leads us to consider alternative organ sources such as HCV-positive donors. The outcomes of these transplants must be evaluated thoroughly since there is universal recurrence of disease among HCV-positive liver transplant recipients. From January 2005 to April 2011, we performed 143 liver transplants (OLT) to treat end-stage liver disease secondary to HCV infection. Thirteen patients (9,1%) received livers from HCV-positive donors. A control group consisted of 130 HCV-positive patients who underwent OLT during the same period with organs from HCV-negative donors. Donor HCV status was assessed by 2 tests: HCV antibodies and viral load. Not only recipient and graft survivals were analyzed, but also frequency, timing and severity of hepatitis recurrence. Among 143 transplants performed in HCV-positive recipients during a 6-year period from January 1, 2005, to April 30, 2011, 9.1% of patients received an organ from an anti-HCV-positive donor, 72.7% of whom showed a negative viral load. The vast majority (80%) of our patients suffered hepatitis during their follow-up, 22.4% of which were severe cases. No significant difference in patient or graft survival was observed between the 2 groups. A high percentage of grafts with initial positive serology for HCV showed no viral replication. Grafts from HCV-positive donors can be considered to be a safe, effective source for liver donation. Copyright © 2012 Elsevier Inc. All rights reserved.

Viral-Associated GN: Hepatitis C and HIV.

PubMed

Kupin, Warren L

2017-08-07

Viruses are capable of inducing a wide spectrum of glomerular disorders that can be categorized on the basis of the duration of active viremia: acute, subacute, or chronic. The variable responses of the adaptive immune system to each time period of viral infection results mechanistically in different histologic forms of glomerular injury. The unique presence of a chronic viremic carrier state with either hepatitis C (HCV) or HIV has led to the opportunity to study in detail various pathogenic mechanisms of viral-induced glomerular injury, including direct viral infection of renal tissue and the development of circulating immune complexes composed of viral antigens that deposit along the glomerular basement membrane. Epidemiologic data show that approximately 25%-30% of all HIV patients are coinfected with HCV and 5%-10% of all HCV patients are coinfected with HIV. This situation can often lead to a challenging differential diagnosis when glomerular disease occurs in this dual-infected population and requires the clinician to be familiar with the clinical presentation, laboratory workup, and pathophysiology behind the development of renal disease for both HCV and HIV. Both of these viruses can be categorized under the new classification of infection-associated GN as opposed to being listed as causes of postinfectious GN as has previously been applied to them. Neither of these viruses lead to renal injury after a latent period of controlled and inactive viremia. The geneses of HCV- and HIV-associated glomerular diseases share a total dependence on the presence of active viral replication to sustain renal injury so the renal disease cannot be listed under "postinfectious" GN. With the new availability of direct-acting antivirals for HCV and more effective combined antiretroviral therapy for HIV, successful remission and even regression of glomerular lesions can be achieved if initiated at an early stage. Copyright © 2017 by the American Society of Nephrology.

Systematic identification of anti-interferon function on hepatitis C virus genome reveals p7 as an immune evasion protein.

PubMed

Qi, Hangfei; Chu, Virginia; Wu, Nicholas C; Chen, Zugen; Truong, Shawna; Brar, Gurpreet; Su, Sheng-Yao; Du, Yushen; Arumugaswami, Vaithilingaraja; Olson, C Anders; Chen, Shu-Hua; Lin, Chung-Yen; Wu, Ting-Ting; Sun, Ren

2017-02-21

Hepatitis C virus (HCV) encodes mechanisms to evade the multilayered antiviral actions of the host immune system. Great progress has been made in elucidating the strategies HCV employs to down-regulate interferon (IFN) production, impede IFN signaling transduction, and impair IFN-stimulated gene (ISG) expression. However, there is a limited understanding of the mechanisms governing how viral proteins counteract the antiviral functions of downstream IFN effectors due to the lack of an efficient approach to identify such interactions systematically. To study the mechanisms by which HCV antagonizes the IFN responses, we have developed a high-throughput profiling platform that enables mapping of HCV sequences critical for anti-IFN function at high resolution. Genome-wide profiling performed with a 15-nt insertion mutant library of HCV showed that mutations in the p7 region conferred high levels of IFN sensitivity, which could be alleviated by the expression of WT p7 protein. This finding suggests that p7 protein of HCV has an immune evasion function. By screening a liver-specific ISG library, we identified that IFI6-16 significantly inhibits the replication of p7 mutant viruses without affecting WT virus replication. In contrast, knockout of IFI6-16 reversed the IFN hypersensitivity of p7 mutant virus. In addition, p7 was found to be coimmunoprecipitated with IFI6-16 and to counteract the function of IFI6-16 by depolarizing the mitochondria potential. Our data suggest that p7 is a critical immune evasion protein that suppresses the antiviral IFN function by counteracting the function of IFI6-16.

Identification of a Functional, CRM-1-Dependent Nuclear Export Signal in Hepatitis C Virus Core Protein

PubMed Central

Cerutti, Andrea; Maillard, Patrick; Minisini, Rosalba; Vidalain, Pierre-Olivier; Roohvand, Farzin; Pecheur, Eve-Isabelle; Pirisi, Mario; Budkowska, Agata

2011-01-01

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS), but no nuclear export signal (NES) has yet been identified. We show here that the aa(109–133) region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126) in the identified NES or in the sequence encoding the mature core aa(1–173) significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication. Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection. PMID:22039426

Alirocumab, a Therapeutic Human Antibody to PCSK9, Does Not Affect CD81 Levels or Hepatitis C Virus Entry and Replication into Hepatocytes.

PubMed

Ramanathan, Aarti; Gusarova, Viktoria; Stahl, Neil; Gurnett-Bander, Anne; Kyratsous, Christos A

2016-01-01

Proprotein convertase subtilisin/kexin type 9 (PSCK9) is secreted mainly from the liver and binds to the low-density lipoprotein receptor (LDLR), reducing LDLR availability and thus resulting in an increase in LDL-cholesterol. While the LDLR has been implicated in the cell entry process of the hepatitis C virus (HCV), overexpression of an artificial non-secreted, cell membrane-bound form of PCSK9 has also been shown to reduce surface expression of CD81, a major component of the HCV entry complex, leading to concerns that pharmacological inhibition of PCSK9 may increase susceptibility to HCV infection by increasing either CD81 or LDLR availability. Here, we evaluated effects of PCSK9 and PCSK9 blockade on CD81 levels and HCV entry with a physiologically relevant model using native secreted PCSK9 and a monoclonal antibody to PCSK9, alirocumab. Flow cytometry and Western blotting of human hepatocyte Huh-7 cells showed that, although LDLR levels were reduced when cells were exposed to increasing PCSK9 concentrations, there was no correlation between total or surface CD81 levels and the presence and amount of soluble PCSK9. Moreover, inhibiting PCSK9 with the monoclonal antibody alirocumab did not affect expression levels of CD81. In an in vitro model of HCV entry, addition of soluble PCSK9 or treatment with alirocumab had no effect on the ability of either lentiviral particles bearing the HCV glycoproteins or JFH-1 based cell culture virus to enter hepatocytes. Consistent with these in vitro findings, no differences were observed in hepatic CD81 levels using in vivo mouse models, including Pcsk9-/- mice compared with wild-type controls and hyperlipidemic mice homozygous for human Pcsk9 and heterozygous for Ldlr deletion, treated with either alirocumab or isotype control antibody. These results suggest that inhibition of PCSK9 with alirocumab has no effect on CD81 and does not result in increased susceptibility to HCV entry.

HCV RNA Genomic sequences and HCV-E2 glycoprotein in sural nerve biopsies from HCV-infected patients with peripheral neuropathy.

PubMed

Russi, S; Sansonno, D; Monaco, S; Mariotto, S; Ferrari, S; Pavone, F; Lauletta, G; Dammacco, F

2018-06-01

Peripheral neuropathy (PN), the major neurological complication of chronic HCV infection, is frequently associated with mixed cryoglobulinaemia (MC) and small-vessel systemic vasculitis. While humoral and cell-mediated immune mechanisms are suspected to act together in an aberrant immune response that results in peripheral nerve damage, the role of HCV remains largely speculative. The possible demonstration of HCV in peripheral nerve tissue would obviously assume important pathogenic implications. We studied sural nerve biopsies from 11 HCV-positive patients with neuropathic symptoms: five with and six without MC. In situ hybridization (ISH) and immunofluorescence studies were carried out to detect genomic and antigenomic HCV RNA sequences and HCV-encoded E2-glycoprotein, respectively. Epineurial vascular deposits of E2-glycoprotein were found in four (80%) MC and in two (33.3%) non-MC patients, respectively. These findings were enhanced by the perivascular deposition of positive-, though not negative-strand replicative RNA, as also found in the nerve extracts of all patients. Mild inflammatory cell infiltrates with no deposits of immunoglobulins and/or complement proteins were revealed around small vessels, without distinct vasculitis changes between MC and non-MC patients. These results indicate that nerve vascular HCV RNA/E2 deposits associated to perivascular inflammatory infiltrates were similar in chronically HCV-infected patients, regardless of cryoglobulin occurrence. Given the failure to demonstrate HCV productive infection in the examined sural nerve biopsies, nerve damage is likely to result from virus-triggered immune-mediated mechanisms. © 2017 British Neuropathological Society.

[Low-molecular-weight regulators of biogenic polyamine metabolism affect cytokine production and expression of hepatitis С virus proteins in Huh7.5 human hepatocarcinoma cells].

PubMed

Masalova, O V; Lesnova, E I; Samokhvalov, E I; Permyakova, K Yu; Ivanov, A V; Kochetkov, S N; Kushch, A A

2017-01-01

Hepatitis C virus (HCV) induces the expression of the genes of proinflammatory cytokines, the excessive production of which may cause cell death, and contribute to development of liver fibrosis and hepatocarcinoma. The relationship between cytokine production and metabolic disorders in HCV-infected cells remains obscure. The levels of biogenic polyamines, spermine, spermidine, and their precursor putrescine, may be a potential regulator of these processes. The purpose of the present work was to study the effects of the compounds which modulate biogenic polyamines metabolism on cytokine production and HCV proteins expression. Human hepatocarcinoma Huh7.5 cells have been transfected with the plasmids that encode HCV proteins and further incubated with the following low-molecular compounds that affect different stages of polyamine metabolism: (1) difluoromethylornithine (DFMO), the inhibitor of ornithine decarboxylase, the enzyme that catalyzes the biosynthesis of polyamines; (2) N,N'-bis(2,3-butane dienyl)-1,4-diaminobutane (MDL72.527), the inhibitor of proteins involved in polyamine degradation; and (3) synthetic polyamine analog N^(I),N^(II)-diethylnorspermine (DENSpm), an inducer of polyamine degradation enzyme. The intracellular accumulation and secretion of cytokines (IL-6, IL-1β, TNF-α, and TGF-β) was assessed by immunocytochemistry and in the immunoenzyme assay, while the cytokine gene expression was studied using reverse transcription and PCR. The effects of the compounds under analysis on the expression of HCV proteins were analyzed using the indirect immunofluorescence with anti-HCV monoclonal antibodies. It has been demonstrated that, in cells transfected with HCV genes, DFMO reduces the production of three out of four tested cytokines, namely, TNF-α and TGF-β in cells that express HCV core, Е1Е2, NS3, NS5A, and NS5B proteins, and IL-1β in the cells that express HCV core, Е1Е2, and NS3 proteins. MDL72527 and DENSpm decreased cytokine production to a lesser extent. Incubation with DFMO led to a 28-32% decrease in the number of cells expressing NS5B or NS5A, both of which are key components of the HCV replication complex. The results obtained in the work indicate that a further detailed study of the antiviral activity of DFMO is required in order to assess its potential as an anti-hepatitis C therapeutic agent.

Interaction of Hepatitis C Virus Core Protein with Janus Kinase Is Required for Efficient Production of Infectious Viruses

PubMed Central

Lee, Choongho

2013-01-01

Chronic hepatitis C virus (HCV) infection is responsible for the development of liver cirrhosis and hepatocellular carcinoma. HCV core protein plays not only a structural role in the virion morphogenesis by encapsidating a virus RNA genome but also a non-structural role in HCV-induced pathogenesis by blocking innate immunity. Especially, it has been shown to regulate JAK-STAT signaling pathway through its direct interaction with Janus kinase (JAK) via its proline-rich JAK-binding motif (79PGYPWP84). However, little is known about the physiological significance of this HCV core-JAK association in the context of the virus life cycle. In order to gain an insight, a mutant HCV genome (J6/JFH1-79A82A) was constructed to express the mutant core with a defective JAK-binding motif (79AGYAWP84) using an HCV genotype 2a infectious clone (J6/JFH1). When this mutant HCV genome was introduced into hepatocarcinoma cells, it was found to be severely impaired in its ability to produce infectious viruses in spite of its robust RNA genome replication. Taken together, all these results suggest an essential requirement of HCV core-JAK protein interaction for efficient production of infectious viruses and the potential of using core-JAK blockers as a new anti-HCV therapy. PMID:24009866

Analytical and clinical performance of the Hologic Aptima HCV Quant Dx Assay for the quantification of HCV RNA in plasma samples.

PubMed

Schønning, Kristian; Pedersen, Martin Schou; Johansen, Kim; Landt, Bodil; Nielsen, Lone Gilmor; Weis, Nina; Westh, Henrik

2017-10-01

Chronic hepatitis C virus (HCV) infection can be effectively treated with directly acting antiviral (DAA) therapy. Measurement of HCV RNA is used to evaluate patient compliance and virological response during and after treatment. To compare the analytical performance of the Aptima HCV Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HCV Test v2.0 (CAPCTMv2) for the quantification of HCV RNA in plasma samples, and compare the clinical utility of the two tests in patients undergoing treatment with DAA therapy. Analytical performance was evaluated on two sets of plasma samples: 125 genotyped samples and 172 samples referred for quantification of HCV RNA. Furthermore, performance was evaluated using dilutions series of four samples containing HCV genotype 1a, 2b, 3a, and 4a, respectively. Clinical utility was evaluated on 118 plasma samples obtained from 13 patients undergoing treatment with DAAs. Deming regression of results from 187 plasma samples with HCV RNA >2 Log IU/mL indicated that the Aptima assay quantified higher than the CAPCTMv2 test for HCV RNA >4.9 Log IU/mL. The linearity of the Aptima assay was excellent across dilution series of four HCV genotypes (slope of the regression line: 1.00-1.02). The Aptima assay detected significantly more replicates below targeted 2 Log IU/mL than the CAPCTMv2 test, and yielded clearly interpretable results when used to analyze samples from patients treated with DAAs. The analytical performance of the Aptima assay makes it well suited for monitoring patients with chronic HCV infection undergoing antiviral treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Generation of T-cell receptors targeting a genetically stable and immunodominant cytotoxic T-lymphocyte epitope within hepatitis C virus non-structural protein 3.

PubMed

Pasetto, Anna; Frelin, Lars; Brass, Anette; Yasmeen, Anila; Koh, Sarene; Lohmann, Volker; Bartenschlager, Ralf; Magalhaes, Isabelle; Maeurer, Markus; Sällberg, Matti; Chen, Margaret

2012-02-01

Hepatitis C virus (HCV) is a major cause of severe liver disease, and one major contributing factor is thought to involve a dysfunction of virus-specific T-cells. T-cell receptor (TCR) gene therapy with HCV-specific TCRs would increase the number of effector T-cells to promote virus clearance. We therefore took advantage of HLA-A2 transgenic mice to generate multiple TCR candidates against HCV using DNA vaccination followed by generation of stable T-cell-BW (T-BW) tumour hybrid cells. Using this approach, large numbers of non-structural protein 3 (NS3)-specific functional T-BW hybrids can be generated efficiently. These predominantly target the genetically stable HCV genotype 1 NS3(1073-1081) CTL epitope, frequently associated with clearance of HCV in humans. These T-BW hybrid clones recognized the NS3(1073) peptide with a high avidity. The hybridoma effectively recognized virus variants and targeted cells with low HLA-A2 expression, which has not been reported previously. Importantly, high-avidity murine TCRs effectively redirected human non-HCV-specific T-lymphocytes to recognize human hepatoma cells with HCV RNA replication driven by a subgenomic HCV replicon. Taken together, TCR candidates with a range of functional avidities, which can be used to study immune recognition of HCV-positive targets, have been generated. This has implications for TCR-related immunotherapy against HCV.

Role of HCV Core gene of genotype 1a and 3a and host gene Cox-2 in HCV-induced pathogenesis

PubMed Central

2011-01-01

Background Hepatitis C virus (HCV) Core protein is thought to trigger activation of multiple signaling pathways and play a significant role in the alteration of cellular gene expression responsible for HCV pathogenesis leading to hepatocellular carcinoma (HCC). However, the exact molecular mechanism of HCV genome specific pathogenesis remains unclear. We examined the in vitro effects of HCV Core protein of HCV genotype 3a and 1a on the cellular genes involved in oxidative stress and angiogenesis. We also studied the ability of HCV Core and Cox-2 siRNA either alone or in combination to inhibit viral replication and cell proliferation in HCV serum infected Huh-7 cells. Results Over expression of Core gene of HCV 3a genotype showed stronger effect in regulating RNA and protein levels of Cox-2, iNOS, VEGF, p-Akt as compared to HCV-1a Core in hepatocellular carcinoma cell line Huh-7 accompanied by enhanced PGE2 release and cell proliferation. We also observed higher expression levels of above genes in HCV 3a patient's blood and biopsy samples. Interestingly, the Core and Cox-2-specific siRNAs down regulated the Core 3a-enhanced expression of Cox-2, iNOS, VEGF, p-Akt. Furthermore, the combined siRNA treatment also showed a dramatic reduction in viral titer and expression of these genes in HCV serum-infected Huh-7 cells. Taken together, these results demonstrated a differential response by HCV 3a genotype in HCV-induced pathogenesis, which may be due to Core and host factor Cox-2 individually or in combination. Conclusions Collectively, these studies not only suggest a genotype-specific interaction between key players of HCV pathogenesis but also may represent combined viral and host gene silencing as a potential therapeutic strategy. PMID:21457561

Identification and Linkage to Care of HCV-Infected Persons in Five Health Centers - Philadelphia, Pennsylvania, 2012-2014.

PubMed

Coyle, Catelyn; Viner, Kendra; Hughes, Elizabeth; Kwakwa, Helena; Zibbell, Jon E; Vellozzi, Claudia; Holtzman, Deborah

2015-05-08

Approximately three million persons in the United States are infected with hepatitis C virus (HCV), a blood-borne pathogen that is an increasing cause of liver disease and mortality in the United States. Treatments for HCV are curative, of short duration, and have few associated side effects, increasing the importance of identifying HCV-infected persons. Many persons with HCV infection were infected decades ago, before implementation of prevention measures and most are unaware of their infection, regardless of when it occurred. Most newly diagnosed cases are associated with injection drug use. Persons born during 1945-1965 have a fivefold higher risk of HCV infection than other adults and the highest risk for HCV-related morbidity and mortality. CDC recommends testing for this group, for persons who inject drugs, and others at risk for HCV infection. From October 2012 through July 2014, the National Nursing Centers Consortium (NNCC) carried out a project to integrate routine HCV testing and linkage-to-care in five federally qualified health centers in Philadelphia, PA, that primarily serve homeless persons and public housing residents. During the project period, 4,514 patients across the five centers were tested for HCV. Of these, 595 (13.2%) were HCV-antibody positive and 550 (92.4%) had a confirmatory HCV-RNA test performed. Of those who had a confirmatory HCV-RNA test performed, 390 (70.9%) were identified as having current (i.e., chronic) HCV infection (overall prevalence = 8.6%). Of those currently infected with HCV, 90% were informed of their status, 78% were referred to an HCV care specialist, and 62% went to the referred specialist for care. Replicable system modifications that improved HCV testing and care included enhancements to electronic medical records (EMRs), simplification of HCV testing protocols, and addition of a linkage-to-care coordinator. Findings from this project highlight the need for innovative strategies for HCV testing, care, and treatment, as well as the important role of community health centers in expanding access for patient populations disproportionately affected by HCV infection.

In situ hybridization of hepatitis C virus RNA in liver cells of an experimentally infected rhesus macaque.

PubMed

Majerowicz, Selma; Grief, Christopher; Ferguson, Debora; Airano, Renata C; Baptista, Marcia L; Pinto, Marcelo A; Barth, Ortrud Monika

2004-10-01

The liver tissue of a rhesus macaque inoculated with hepatitis C virus (HCV) has been analyzed for the presence of HCV RNA using the technique of in situ hybridization, both at light and electron microscopy levels. The animal was inoculated by the intrasplenic route using a HCV infected autogenic hepatocyte transplant. The serum sample used to infect the hepatocyte cells was characterized by polymerase chain reaction technique and shown to be positive for HCV RNA, genotype 3 with 10(7) RNA copies/ml. In situ hybridization was performed using a complementary negative strand probe made with the specific primer. We were able to detect and localize viral RNA in altered membranes of the rough endoplasmic reticulum of infected liver cells, showing evidence of virus replication in vivo.

TIM-1 Promotes Hepatitis C Virus Cell Attachment and Infection.

PubMed

Wang, Jing; Qiao, Luhua; Hou, Zhouhua; Luo, Guangxiang

2017-01-15

Human TIM and TAM family proteins were recently found to serve as phosphatidylserine (PS) receptors which promote infections by many different viruses, including dengue virus, West Nile virus, Ebola virus, Marburg virus, and Zika virus. In the present study, we provide substantial evidence demonstrating that TIM-1 is important for efficient infection by hepatitis C virus (HCV). The knockdown of TIM-1 expression significantly reduced HCV infection but not HCV RNA replication. Likewise, TIM-1 knockout in Huh-7.5 cells remarkably lowered HCV cell attachment and subsequent HCV infection. More significantly, the impairment of HCV infection in the TIM-1 knockout cells could be restored completely by ectopic expression of TIM-1 but not TIM-3 or TIM-4. Additionally, HCV infection and cell attachment were inhibited by PS but not by phosphatidylcholine (PC), demonstrating that TIM-1-mediated enhancement of HCV infection is PS dependent. The exposure of PS on the HCV envelope was confirmed by immunoprecipitation of HCV particles with a PS-specific monoclonal antibody. Collectively, these findings demonstrate that TIM-1 promotes HCV infection by serving as an attachment receptor for binding to PS exposed on the HCV envelope. TIM family proteins were recently found to enhance infections by many different viruses, including several members of the Flaviviridae family. However, their importance in HCV infection has not previously been examined experimentally. The TIM family proteins include three members in humans: TIM-1, TIM-3, and TIM-4. The findings derived from our studies demonstrate that TIM-1, but not TIM-3 or TIM-4, promotes HCV infection by functioning as an HCV attachment factor. Knockout of the TIM-1 gene resulted in a remarkable reduction of HCV cell attachment and infection. PS-containing liposomes blocked HCV cell attachment and subsequent HCV infection. HCV particles could also be precipitated with a PS-specific monoclonal antibody. These findings suggest that TIM-1 and its binding ligand, PS, may serve as novel targets for antiviral intervention. Copyright © 2017 American Society for Microbiology.

Binding of Free and Immune Complex-Associated Hepatitis C Virus to Erythrocytes Is Mediated by the Complement System.

PubMed

Salam, Kazi Abdus; Wang, Richard Y; Grandinetti, Teresa; De Giorgi, Valeria; Alter, Harvey J; Allison, Robert D

2018-05-09

Erythrocytes bind circulating immune complexes (IC) and facilitate IC clearance from the circulation. Chronic hepatitis C virus (HCV) infection is associated with IC-related disorders. In this study we investigated the kinetics and mechanism of HCV and HCV-IC binding to and dissociation from erythrocytes. Cell culture-produced HCV was mixed with erythrocytes from healthy blood donors and erythrocyte-associated virus particles were quantified. Purified complement proteins, complement-depleted serum, and complement receptor antibodies were used to investigate complement-mediated HCV-erythrocyte binding. Purified HCV-specific immunoglobulin G from a chronic HCV-infected patient was used to study complement-mediated HCV-IC-erythrocyte binding. Binding of HCV to erythrocytes increased 200 to 1,000 fold after adding complement active human serum in the absence of antibody. Opsonization of free HCV occurred within 10 minutes and peak binding to erythrocytes was observed at 20-30 minutes. Complement protein C1 was required for binding, while C2, C3 and C4 significantly enhanced binding. Complement receptor 1 (CR1, CD35) antibodies blocked the binding of HCV to erythrocytes isolated from chronically infected HCV patients and healthy blood donors. HCV-ICs significantly enhanced complement-mediated binding to erythrocytes compared to unbound HCV. Dissociation of complement-opsonized HCV from erythrocytes depended on the presence of Factor I. HCV released by Factor I bound preferentially to CD19+ B cells compared to other leukocytes. These results demonstrate that complement mediates the binding of free and IC-associated HCV to CR1 on erythrocytes, and provide a mechanistic rationale for investigating the differential phenotypic expression of HCV-IC-related disease. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Antiviral Activity of Glycyrrhizin against Hepatitis C Virus In Vitro

PubMed Central

Matsumoto, Yoshihiro; Matsuura, Tomokazu; Aoyagi, Haruyo; Matsuda, Mami; Hmwe, Su Su; Date, Tomoko; Watanabe, Noriyuki; Watashi, Koichi; Suzuki, Ryosuke; Ichinose, Shizuko; Wake, Kenjiro; Suzuki, Tetsuro; Miyamura, Tatsuo; Wakita, Takaji; Aizaki, Hideki

2013-01-01

Glycyrrhizin (GL) has been used in Japan to treat patients with chronic viral hepatitis, as an anti-inflammatory drug to reduce serum alanine aminotransferase levels. GL is also known to exhibit various biological activities, including anti-viral effects, but the anti-hepatitis C virus (HCV) effect of GL remains to be clarified. In this study, we demonstrated that GL treatment of HCV-infected Huh7 cells caused a reduction of infectious HCV production using cell culture-produced HCV (HCVcc). To determine the target step in the HCV lifecycle of GL, we used HCV pseudoparticles (HCVpp), replicon, and HCVcc systems. Significant suppressions of viral entry and replication steps were not observed. Interestingly, extracellular infectivity was decreased, and intracellular infectivity was increased. By immunofluorescence and electron microscopic analysis of GL treated cells, HCV core antigens and electron-dense particles had accumulated on endoplasmic reticulum attached to lipid droplet (LD), respectively, which is thought to act as platforms for HCV assembly. Furthermore, the amount of HCV core antigen in LD fraction increased. Taken together, these results suggest that GL inhibits release of infectious HCV particles. GL is known to have an inhibitory effect on phospholipase A2 (PLA2). We found that group 1B PLA2 (PLA2G1B) inhibitor also decreased HCV release, suggesting that suppression of virus release by GL treatment may be due to its inhibitory effect on PLA2G1B. Finally, we demonstrated that combination treatment with GL augmented IFN-induced reduction of virus in the HCVcc system. GL is identified as a novel anti-HCV agent that targets infectious virus particle release. PMID:23874843

Apolipoprotein B100 is required for hepatitis C infectivity and Mipomersen inhibits hepatitis C.

PubMed

Schaefer, Esperance A K; Meixiong, James; Mark, Christina; Deik, Amy; Motola, Daniel L; Fusco, Dahlene; Yang, Andrew; Brisac, Cynthia; Salloum, Shadi; Lin, Wenyu; Clish, Clary B; Peng, Lee F; Chung, Raymond T

2016-12-07

To characterize the role of apolipoprotein B100 (apoB100) in hepatitis C viral (HCV) infection. In this study, we utilize a gene editing tool, transcription activator-like effector nucleases (TALENs), to generate human hepatoma cells with a stable genetic deletion of APOB to assess of apoB in HCV. Using infectious cell culture-competent HCV, viral pseudoparticles, replicon models, and lipidomic analysis we determined the contribution of apoB to each step of the viral lifecycle. We further studied the effect of mipomersen, an FDA-approved antisense inhibitor of apoB100, on HCV using in vitro cell-culture competent HCV and determined its impact on viral infectivity with the TCID50 method. We found that apoB100 is indispensable for HCV infection. Using the JFH-1 fully infectious cell-culture competent virus in Huh 7 hepatoma cells with TALEN-mediated gene deletion of apoB ( APOB KO ), we found a significant reduction in HCV RNA and protein levels following infection. Pseudoparticle and replicon models demonstrated that apoB did not play a role in HCV entry or replication. However, the virus produced by APOB KO cells had significantly diminished infectivity as measured by the TCID-50 method compared to wild-type virus. Lipidomic analysis demonstrated that these virions have a fundamentally altered lipidome, with complete depletion of cholesterol esters. We further demonstrate that inhibition of apoB using mipomersen, an FDA-approved anti-sense oligonucleotide, results in a potent anti-HCV effect and significantly reduces the infectivity of the virus. ApoB is required for the generation of fully infectious HCV virions, and inhibition of apoB with mipomersen blocks HCV. Targeting lipid metabolic pathways to impair viral infectivity represents a novel host targeted strategy to inhibit HCV.

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication

PubMed Central

Magri, Andrea; Ozerov, Alexander A.; Tunitskaya, Vera L.; Valuev-Elliston, Vladimir T.; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V.; Novikov, Mikhail S.; Patel, Arvind H.

2016-01-01

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N3-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N1 position. PMID:27406141

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication.

PubMed

Magri, Andrea; Ozerov, Alexander A; Tunitskaya, Vera L; Valuev-Elliston, Vladimir T; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V; Novikov, Mikhail S; Patel, Arvind H

2016-07-12

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N(3)-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N(1) position.

Oral manifestations of hepatitis C virus infection

PubMed Central

Carrozzo, Marco; Scally, Kara

2014-01-01

Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV. PMID:24976694

In vitro neutralization of HCV by goat antibodies against peptides encompassing regions downstream of HVR-1 of E2 glycoprotein.

PubMed

Tabll, Ashraf A; Atef, Khaled; Bader El Din, Noha G; El Abd, Yasmine S; Salem, Ahmed; Sayed, Ahmed A; Dawood, Reham M; Omran, Moataza H; El-Awady, Mostafa K

2014-01-01

This article aims at testing several in vitro systems with various viral sources and cell lines for propagation of HCV to evaluate goat antibodies raised against three E2 epitopes in viral neutralization experiments. Four human cell lines (Huh-7, Huh-7.5, HepG2, and CaCo2) were tested using two different HCV viral sources; Genotype 4 infected sera and J6/JFH HCV cc particles. Neutralization capacity of goat Abs against conserved E2 epitopes; p412 (a.a 412-419), p517 (a.a 517-531), and p430 (a.a 430-447) were examined in the above mentioned in vitro systems. Although infection with patients' sera seems to mimic the in vitro situation, it has limited replication rates as compared with HCV cc particularly in Huh7.5 cells. Non-HCV adapted Huh-7 cells were also found susceptible for transfection with J6/JFH virus but at much slower kinetics. The results of the neutralization assay showed that anti p412 and anti p517 were highly neutralizing to HCVcc. Our data demonstrate that antibodies directed against the viral surface glycoprotein E2 reduced the infectivity of the J6/JFH virus and are promising agents for immunotherapy and HCV vaccine development.

Phenotypic analysis of NS5A variant from liver transplant patient with increased cyclosporine susceptibility

PubMed Central

Ansari, Israr-ul H.; Allen, Todd; Berical, Andrew; Stock, Peter G.; Barin, Burc; Striker, Rob

2013-01-01

Hepatitis C virus (HCV) replication is limited by cyclophilin inhibitors but it remains unclear how viral genetic variations influence susceptibility to cyclosporine (cyclosporine A, CsA), a cyclophilin inhibitor. In this study HCV from liver transplant patients was sequenced before and after CsA exposure. Phenotypic analysis of NS5A sequence was performed by using HCV sub genomic replicon to determine CsA susceptibility. The data indicates an atypical proline at position 328 in NS5A causes increases CsA sensitivity both in the context of genotype 1a and 1b residues. Point mutants mimicking other naturally occurring residues at this position also increased (Ala) or decreased (Arg) replicon sensitivity to CsA relative to the typical threonine (genotype 1a) or serine (genotype 1b) at this position. This work has implications for treatment of HCV by cyclophilin inhibitors. PMID:23290631

Identification of drug resistance and immune-driven variations in hepatitis C virus (HCV) NS3/4A, NS5A and NS5B regions reveals a new approach toward personalized medicine.

PubMed

Ikram, Aqsa; Obaid, Ayesha; Awan, Faryal Mehwish; Hanif, Rumeza; Naz, Anam; Paracha, Rehan Zafar; Ali, Amjad; Janjua, Hussnain Ahmed

2017-01-01

Cellular immune responses (T cell responses) during hepatitis C virus (HCV) infection are significant factors for determining the outcome of infection. HCV adapts to host immune responses by inducing mutations in its genome at specific sites that are important for HLA processing/presentation. Moreover, HCV also adapts to resist potential drugs that are used to restrict its replication, such as direct-acting antivirals (DAAs). Although DAAs have significantly reduced disease burden, resistance to these drugs is still a challenge for the treatment of HCV infection. Recently, drug resistance mutations (DRMs) observed in HCV proteins (NS3/4A, NS5A and NS5B) have heightened concern that the emergence of drug resistance may compromise the effectiveness of DAAs. Therefore, the NS3/4A, NS5A and NS5B drug resistance variations were investigated in this study, and their prevalence was examined in a large number of protein sequences from all HCV genotypes. Furthermore, potential CD4 + and CD8 + T cell epitopes were predicted and their overlap with genetic variations was explored. The findings revealed that many reported DRMs within NS3/4A, NS5A and NS5B are not drug-induced; rather, they are already present in HCV strains, as they were also detected in HCV-naïve patients. This study highlights several hot spots in which HLA and drug selective pressure overlap. Interestingly, these overlapping mutations were frequently observed among many HCV genotypes. This study implicates that knowledge of the host HLA type and HCV subtype/genotype can provide important information in defining personalized therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Resistance to cyclosporin A derives from mutations in hepatitis C virus nonstructural proteins.

PubMed

Arai, Masaaki; Tsukiyama-Kohara, Kyoko; Takagi, Asako; Tobita, Yoshimi; Inoue, Kazuaki; Kohara, Michinori

2014-05-23

Cyclosporine A (CsA) is an immunosuppressive drug that targets cyclophilins, cellular cofactors that regulate the immune system. Replication of hepatitis C virus (HCV) is suppressed by CsA, but the molecular basis of this suppression is still not fully understood. To investigate this suppression, we cultured HCV replicon cells (Con1, HCV genotype 1b, FLR-N cell) in the presence of CsA and obtained nine CsA-resistant FLR-N cell lines. We determined full-length HCV sequences for all nine clones, and chose two (clones #6 and #7) of the nine clones that have high replication activity in the presence of CsA for further analysis. Both clones showed two consensus mutations, one in NS3 (T1280V) and the other in NS5A (D2292E). Characterization of various mutants indicated that the D2292E mutation conferred resistance to high concentrations of CsA (up to 2 μM). In addition, the missense mutation T1280V contributed to the recovery of colony formation activity. The effects of these mutations are also evident in two established HCV replicon cell lines-HCV-RMT ([1], genotype 1a) and JFH1 (genotype 2a). Moreover, three other missense mutations in NS5A-D2303H, S2362G, and E2414K-enhanced the resistance to CsA conferred by D2292E; these double or all quadruple mutants could resist approximately 8- to 25-fold higher concentrations of CsA than could wild-type Con1. These four mutations, either as single or combinations, also made Con1 strain resistant to two other cyclophilin inhibitors, N-methyl-4-isoleucine-cyclosporin (NIM811) or Debio-025. Interestingly, the changes in IC50 values that resulted from each of these mutations were the lowest in the Debio-025-treated cells, indicating its highest resistant activity against the adaptive mutation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Antiviral therapy of hepatitis C in 2014: do we need resistance testing?

PubMed

Schneider, Maximilian David; Sarrazin, Christoph

2014-05-01

The treatment of chronic hepatitis C has fundamentally changed since the approval of the first direct-acting antivirals (DAA) in 2011. In addition to telaprevir and boceprevir, in 2014 two new NS3 protease inhibitors (simeprevir and faldaprevir), one non-nucleoside polymerase inhibitor (sofosbuvir) and one NS5a replication complex inhibitor (daclatasvir) have expanded the treatment options for chronic hepatitis C. Resistance-associated variants (RAV) are naturally produced during the HCV life cycle. The frequency of RAVs within HCV quasispecies mainly depends on their replicational fitness. Variants conferring resistance to nucleos(t)ide analogues have not been detected, and the majority of NS3 protease-resistant variants are present at low frequencies (0.1-3%) before initiation of DAA-based therapies. However, the Q80K variant conferring resistance to simeprevir has been observed in 9-48% of untreated HCV genotype 1a-infected patients, leading to reduced SVR rates. Resistant variants are detectable in the majority of patients with treatment failure to NS3 protease inhibitor- or NS5a inhibitor-based antiviral therapy. Long-term follow-up studies by population-based sequence analysis have shown the disappearance of resistant variants in the majority of patients, with median times to loss of mutations of 4-64weeks. For the nucleotide analogue sofosbuvir, the emergence of the S282T resistant variant has been observed only in single patients, with reversion to wild-type within several weeks. Data are sparse on retreatment of patients with the same DAA or the same class of DAAs. However, retreatment with a different class of DAAs after failure of NS3 protease inhibitor-based therapy has been successful in small studies. This article forms part of a symposium in Antiviral Research on "Hepatitis C: next steps toward global eradication." Copyright © 2014 Elsevier B.V. All rights reserved.

HCV-like IRESs displace eIF3 to gain access to the 40S subunit

PubMed Central

Hashem, Yaser; des Georges, Amedee; Dhote, Vidya; Langlois, Robert; Liao, Hstau Y.; Grassucci, Robert A.; Pestova, Tatyana V.; Hellen, Christopher U.T.; Frank, Joachim

2014-01-01

Hepatitis C virus (HCV) and Classical swine fever virus (CSFV) mRNAs contain related (HCV-like) internal ribosome entry sites (IRESs) that promote 5’-end independent initiation of translation, requiring only a subset of the eukaryotic initiation factors (eIFs) needed for canonical initiation on cellular mRNAs1. Initiation on HCV-like IRESs relies on their specific interaction with the 40S subunit2–8, which places the initiation codon into the P site, where it directly base-pairs with eIF2-bound Met-tRNAiMet to form a 48S initiation complex. However, all HCV-like IRESs also specifically interact with eIF32,5–7,9–12, but the role of this interaction in IRES-mediated initiation has remained unknown. During canonical initiation, eIF3 binds to the 40S subunit as a component of the 43S pre-initiation complex, and comparison of the ribosomal positions of eIF313 and the HCV IRES8 revealed that they overlap, so that their rearrangement would be required for formation of ribosomal complexes containing both components13. Here, we present a cryo-electron microscopy reconstruction of a 40S ribosomal complex containing eIF3 and the CSFV IRES. Strikingly, although the position and interactions of the CSFV IRES with the 40S subunit in this complex are similar to those of the HCV IRES in the 40S/IRES binary complex8, eIF3 is completely displaced from its ribosomal position in the 43S complex, and instead interacts through its ribosome-binding surface exclusively with the apical region of domain III of the IRES. Our results suggest a role for the specific interaction of HCV-like IRESs with eIF3 in preventing ribosomal association of eIF3, which could serve two purposes: relieving the competition between the IRES and eIF3 for a common binding site on the 40S subunit, and reducing formation of 43S complexes, thereby favoring translation of viral mRNAs. PMID:24185006

Human Interferon Regulatory Factor 2 Gene Expression is Induced in Chronic Hepatitis C Virus Infection—A Possible Mode of Viral Persistence

PubMed Central

Mukherjee, Rathindra M; Bansode, Budhapriyavilas; Gangwal, Puja; Jakkampudi, Aparna; Reddy, Panyala B; Rao, Padaki N; Gupta, Rajesh; Reddy, D Nageshwar

2012-01-01

Background The interferon regulatory factors (IRFs) are a family of transcription factors known to be involved in the modulation of cellular responses to interferons (IFNs) and viral infection. While IRF-1 acts as a positive regulator, IRF-2 is known to repress IFN-mediated gene expression. The increase in the IRF-1/IRF-2 ratio is considered as an important event in the transcriptional activation of IFN-α gene toward development of the cellular antiviral response. Objective This study was performed to assess the expression of IRF mRNAs along with the expression level of IFN-α, its receptor (IFNAR-1), and the signal transduction factor (STAT-1) in treatment naive hepatitis C virus (HCV)-infected subjects. Materials Thirty-five chronically infected (CHC) patients and 39 voluntary blood donors as controls were included in the study. Quantification of HCV-RNA (ribonucleic acid) and genotyping were done by real-time polymerase chain reaction (PCR) and hybridization assays, respectively, using patient's serum/plasma. In both controls and patients, the serum level of IFN-α and IFN-α was measured by flow cytometry. Target gene expressions were studied by retro-transcription of respective mRNAs extracted from peripheral blood mononuclear cells (PBMCs) followed by PCR amplification and densitometry. Minus-strand HCV-RNA as a marker of viral replication in PBMCs was detected by an inhouse PCR assay. Results Both IRF-1 and IRF-2 genes were significantly enhanced in CHC than in control subjects (P < 0.001). A significant positive correlation (r2 = 0.386, P <0.01) was obtained between higher IRF-2 gene expression and increasing level of HCV-RNA. Chronically infected subjects (13%) harboring replicating HCV in PBMCs showed no significant differences in gene expressions than the subjects without HCV in PBMCs. Conclusion Our findings indicate that HCV modulates host immunity by inducing IRF-2 gene to counteract IRF-1-mediated IFN-α gene expression. Since the IRF-2 gene is known to encode oncogenic protein, the role of IRF-2 in CHC patients developing hepatocellular carcinoma warrants further studies. PMID:25755403

Interaction between Galectin-9/TIM-3 pathway and follicular helper CD4+ T cells contributes to viral persistence in chronic hepatitis C.

PubMed

Zhuo, Ya; Zhang, Yi-Fu; Wu, Hong-Jie; Qin, Lei; Wang, Yan-Ping; Liu, A-Min; Wang, Xin-Hong

2017-10-01

Both Galectin 9 (Gal-9)/T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) pathway and follicular helper CD4 + T (Tfh) cells play important roles in persistent hepatitis C virus (HCV) infection. Thus, we aimed to investigate the regulatory role of interaction between Gal-9/TIM-3 pathway and Tfh cells in chronic hepatitis C. A total of 44 chronic hepatitis C patients and 19 normal controls (NCs) were enrolled in this study. Purified CD4 + T cells were cultured by TIM-3 Fc protein, recombinant Gal-9, or IL-21 for 48h. TIM-3 expression, Tfh proportion, and IL-21 production was measured, respectively. The immunomodulatory role of Gal-9/TIM-3 and IL-21 was also investigated in HCV cell culture system in vitro. We found that the percentage corresponding to both TIM-3-positive and CXCR5 + ICOS + Tfh cells within CD4 + T cells, which correlated with HCV RNA replication, was significantly elevated in patients with chronic hepatitis C in comparison with those in NCs. Moreover, blockade of Gal-9/TIM-3 pathway by TIM-3 Fc protein increased Tfh cells proportion, IL-21 mRNA and protein expression within purified CD4 + T cells, while activation of Gal-9/TIM-3 signaling by Gal-9 stimulation decreased IL-21 production in both patients with chronic HCV infection and healthy individuals. Meanwhile, high concentrations (100 and 200ng/mL) of IL-21 stimulation also elevated TIM-3 expression on CD4 + T cells in chronic hepatitis C. Furthermore, TIM-3 blockage and IL-21 stimulation suppressed mRNA expressions of HCV-induced antiviral proteins (myxovirus resistance A and oligoadenylate synthetase) in Huh7.5 cells without affecting viral replication in HCV cell culture system. The interaction between Gal-9/TIM-3 pathway and Tfh cells contributed to viral persistent in chronic HCV infection, which might be pivotal for development of new therapeutic approaches for chronic hepatitis C. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Influence of IFNL3 and HLA-DPB1 genotype on postpartum control of hepatitis C virus replication and T-cell recovery.

PubMed

Honegger, Jonathan R; Tedesco, Dana; Kohout, Jennifer A; Prasad, Mona R; Price, Aryn A; Lindquist, Tera; Ohmer, Samantha; Moore-Clingenpeel, Melissa; Grakoui, Arash; Walker, Christopher M

2016-09-20

Chronic hepatitis C virus (HCV) infection is characterized by exhaustion of virus-specific T-cells and stable viremia. Pregnancy is an exception. Viremia gradually climbs during gestation but sometimes declines sharply in the months following delivery. Here, we demonstrated that postpartum HCV control was associated with enhanced virus-specific T-cell immunity. Women with viral load declines of at least 1 log10 between the third trimester and 3-mo postpartum exhibited HCV-specific T-cell responses of greater breadth (P = 0.0052) and magnitude (P = 0.026) at 3-mo postpartum than women who failed to control viremia. Moreover, viral dynamics were consistent in women after consecutive pregnancies, suggesting genetic underpinnings. We therefore searched for genetic associations with human leukocyte antigen (HLA) alleles and IFN-λ3 gene (IFNL3) polymorphisms that influence HCV infection outcome. Postpartum viral control was associated with the IFNL3 rs12979860 genotype CC (P = 0.045 at 6 mo) that predicts a positive response to IFN-based therapy. Suppression of virus replication after pregnancy was also strongly influenced by the HLA class II DPB1 locus. HLA-DPB1 alleles are classified by high and low patterns of expression. Carriage of at least one high-expression HLA-DPB1 allele predicted resurgent virus-specific T-cell immunity and viral control at 3-mo postpartum (P = 0.0002). When considered together in multivariable analysis, IFNL3 and HLA-DPB1 independently affected viral control at 3- and 6-mo postpartum. Together, these findings support a model where spontaneous control of HCV such as sometimes follows pregnancy is governed by genetic polymorphisms that affect type III IFN signaling and virus-specific cellular immune responses.

HCV Core Residues Critical for Infectivity Are Also Involved in Core-NS5A Complex Formation

PubMed Central

Gawlik, Katarzyna; Baugh, James; Chatterji, Udayan; Lim, Precious J.; Bobardt, Michael D.; Gallay, Philippe A.

2014-01-01

Hepatitis C virus (HCV) infection is a major cause of liver disease. The molecular machinery of HCV assembly and particle release remains obscure. A better understanding of the assembly events might reveal new potential antiviral strategies. It was suggested that the nonstructural protein 5A (NS5A), an attractive recent drug target, participates in the production of infectious particles as a result of its interaction with the HCV core protein. However, prior to the present study, the NS5A-binding site in the viral core remained unknown. We found that the D1 domain of core contains the NS5A-binding site with the strongest interacting capacity in the basic P38-K74 cluster. We also demonstrated that the N-terminal basic residues of core at positions 50, 51, 59 and 62 were required for NS5A binding. Analysis of all substitution combinations of R50A, K51A, R59A, and R62A, in the context of the HCVcc system, showed that single, double, triple, and quadruple mutants were fully competent for viral RNA replication, but deficient in secretion of viral particles. Furthermore, we found that the extracellular and intracellular infectivity of all the mutants was abolished, suggesting a defect in the formation of infectious particles. Importantly, we showed that the interaction between the single and quadruple core mutants and NS5A was impaired in cells expressing full-length HCV genome. Interestingly, mutations of the four basic residues of core did not alter the association of core or NS5A with lipid droplets. This study showed for the first time that basic residues in the D1 domain of core that are critical for the formation of infectious extracellular and intracellular particles also play a role in core-NS5A interactions. PMID:24533158

Low prevalence of HCV infection with predominance of genotype 4 among HIV patients living in Libreville, Gabon.

PubMed

Ndjoyi-Mbiguino, Angélique; Kombe Kombe, Arnaud John; Bivigou-Mboumba, Berthold; Zoa-Assoumou, Samira; Akombi, Falone Larissa; Nzengui Nzengui, Francis; M'boyis Kamdem, Hervé; François-Souquière, Sandrine

2018-01-01

Gabon is an endemic area for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) and the risk of co-infection is high. Between November 2015 and April 2016, we conducted retrospective study on HCV infection among people living with HIV/AIDS (PLHA). A total of 491 PLHA were included in this study and tested for the presence of HCV infection. HIV viral loads were obtained using the Generic HIV viral Load® assay and the CD4+ T cells count was performed using BD FACSCount™ CD4 reagents. HCV screening was performed using the MP Diagnostics HCV ELISA 4.0 kit. HCV genotypes were determined by sequence analysis of NS5B and Core regions. The Mann-Whitney test was used to compare the groups. Chi-2 test and Fisher's Exact Test were used to compare prevalence. HCV seroprevalence was 2.9% (14/491), (95% confidence interval (CI):1.4-4.3%). The percentage of HCV viremic patients, defined by the detection of HCV RNA in plasma, was 57% (8/14), representing 1.6% of the total population. HCV seroprevalence and replicative infection were not statistically differ with gender. The percentage of co-infection increased with age. No correlation with CD4+ T cells count and HIV viral load level was registered in this study. Identified HCV strains were predominantly of genotype 4 (87.5%) including 4k, 4e, 4g, 4p, 4f and 4c subtypes. Only one strain belonged to genotype 2 (subtype 2q). Analysis of the NS5B region did not reveal the presence of resistance-associated substitutions for sofosbuvir. A systematic screening of hepatitis C is therefore strongly recommended as well as genotyping of HCV strains in order to adapt treatments for the specific case of people living with HIV/AIDS in Central Africa.

Challenge Pools of Hepatitis C Virus Genotypes 1–6 Prototype Strains: Replication Fitness and Pathogenicity in Chimpanzees and Human Liver–Chimeric Mouse Models

PubMed Central

Bukh, Jens; Meuleman, Philip; Tellier, Raymond; Engle, Ronald E.; Feinstone, Stephen M.; Eder, Gerald; Satterfield, William C.; Govindarajan, Sugantha; Krawczynski, Krzysztof; Miller, Roger H.; Leroux-Roels, Geert; Purcell, Robert H.

2010-01-01

Chimpanzees represent the only animal model for studies of the natural history of hepatitis C virus (HCV). To generate virus stocks of important HCV variants, we infected chimpanzees with HCV strains of genotypes 1–6 and determined the infectivity titer of acute-phase plasma pools in additional animals. The courses of first- and second-passage infections were similar, with early appearance of viremia, HCV RNA titers of >104.7 IU/mL, and development of acute hepatitis; the chronicity rate was 56%. The challenge pools had titers of 103–105 chimpanzee infectious doses/mL. Human liver–chimeric mice developed high-titer infections after inoculation with the challenge viruses of genotypes 1–6. Inoculation studies with different doses of the genotype 1b pool suggested that a relatively high virus dose is required to consistently infect chimeric mice. The challenge pools represent a unique resource for studies of HCV molecular virology and for studies of pathogenesis, protective immunity, and vaccine efficacy in vivo. PMID:20353362

RNA synthesis is modulated by G-quadruplex formation in Hepatitis C virus negative RNA strand.

PubMed

Chloé, Jaubert; Amina, Bedrat; Laura, Bartolucci; Carmelo, Di Primo; Michel, Ventura; Jean-Louis, Mergny; Samir, Amrane; Marie-Line, Andreola

2018-05-25

DNA and RNA guanine-rich oligonucleotides can form non-canonical structures called G-quadruplexes or "G4" that are based on the stacking of G-quartets. The role of DNA and RNA G4 is documented in eukaryotic cells and in pathogens such as viruses. Yet, G4 have been identified only in a few RNA viruses, including the Flaviviridae family. In this study, we analysed the last 157 nucleotides at the 3'end of the HCV (-) strand. This sequence is known to be the minimal sequence required for an efficient RNA replication. Using bioinformatics and biophysics, we identified a highly conserved G4-prone sequence located in the stem-loop IIy' of the negative strand. We also showed that the formation of this G-quadruplex inhibits the in vitro RNA synthesis by the RdRp. Furthermore, Phen-DC3, a specific G-quadruplex binder, is able to inhibit HCV viral replication in cells in conditions where no cytotoxicity was measured. Considering that this domain of the negative RNA strand is well conserved among HCV genotypes, G4 ligands could be of interest for new antiviral therapies.

Molecular Basis for the Selective Inhibition of Respiratory Syncytial Virus RNA Polymerase by 2'-Fluoro-4'-Chloromethyl-Cytidine Triphosphate

PubMed Central

Deval, Jerome; Hong, Jin; Wang, Guangyi; Taylor, Josh; Smith, Lucas K.; Fung, Amy; Stevens, Sarah K.; Liu, Hong; Jin, Zhinan; Dyatkina, Natalia; Prhavc, Marija; Stoycheva, Antitsa D.; Serebryany, Vladimir; Liu, Jyanwei; Smith, David B.; Tam, Yuen; Zhang, Qingling; Moore, Martin L.; Fearns, Rachel; Chanda, Sushmita M.; Blatt, Lawrence M.; Symons, Julian A.; Beigelman, Leo

2015-01-01

Respiratory syncytial virus (RSV) causes severe lower respiratory tract infections, yet no vaccines or effective therapeutics are available. ALS-8176 is a first-in-class nucleoside analog prodrug effective in RSV-infected adult volunteers, and currently under evaluation in hospitalized infants. Here, we report the mechanism of inhibition and selectivity of ALS-8176 and its parent ALS-8112. ALS-8176 inhibited RSV replication in non-human primates, while ALS-8112 inhibited all strains of RSV in vitro and was specific for paramyxoviruses and rhabdoviruses. The antiviral effect of ALS-8112 was mediated by the intracellular formation of its 5'-triphosphate metabolite (ALS-8112-TP) inhibiting the viral RNA polymerase. ALS-8112 selected for resistance-associated mutations within the region of the L gene of RSV encoding the RNA polymerase. In biochemical assays, ALS-8112-TP was efficiently recognized by the recombinant RSV polymerase complex, causing chain termination of RNA synthesis. ALS-8112-TP did not inhibit polymerases from host or viruses unrelated to RSV such as hepatitis C virus (HCV), whereas structurally related molecules displayed dual RSV/HCV inhibition. The combination of molecular modeling and enzymatic analysis showed that both the 2'F and the 4'ClCH2 groups contributed to the selectivity of ALS-8112-TP. The lack of antiviral effect of ALS-8112-TP against HCV polymerase was caused by Asn291 that is well-conserved within positive-strand RNA viruses. This represents the first comparative study employing recombinant RSV and HCV polymerases to define the selectivity of clinically relevant nucleotide analogs. Understanding nucleotide selectivity towards distant viral RNA polymerases could not only be used to repurpose existing drugs against new viral infections, but also to design novel molecules. PMID:26098424

The Hepatitis C Virus NS4B Protein Can trans-Complement Viral RNA Replication and Modulates Production of Infectious Virus▿

PubMed Central

Jones, Daniel M.; Patel, Arvind H.; Targett-Adams, Paul; McLauchlan, John

2009-01-01

Studies of the hepatitis C virus (HCV) life cycle have been aided by development of in vitro systems that enable replication of viral RNA and production of infectious virus. However, the functions of the individual proteins, especially those engaged in RNA replication, remain poorly understood. It is considered that NS4B, one of the replicase components, creates sites for genome synthesis, which appear as punctate foci at the endoplasmic reticulum (ER) membrane. In this study, a panel of mutations in NS4B was generated to gain deeper insight into its functions. Our analysis identified five mutants that were incapable of supporting RNA replication, three of which had defects in production of foci at the ER membrane. These mutants also influenced posttranslational modification and intracellular mobility of another replicase protein, NS5A, suggesting that such characteristics are linked to focus formation by NS4B. From previous studies, NS4B could not be trans-complemented in replication assays. Using the mutants that blocked RNA synthesis, defective NS4B expressed from two mutants could be rescued in trans-complementation replication assays by wild-type protein produced by a functional HCV replicon. Moreover, active replication could be reconstituted by combining replicons that were defective in NS4B and NS5A. The ability to restore replication from inactive replicons has implications for our understanding of the mechanisms that direct viral RNA synthesis. Finally, one of the NS4B mutations increased the yield of infectious virus by five- to sixfold. Hence, NS4B not only functions in RNA replication but also contributes to the processes engaged in virus assembly and release. PMID:19073716

Human broadly neutralizing antibodies to the envelope glycoprotein complex of hepatitis C virus.

PubMed

Giang, Erick; Dorner, Marcus; Prentoe, Jannick C; Dreux, Marlène; Evans, Matthew J; Bukh, Jens; Rice, Charles M; Ploss, Alexander; Burton, Dennis R; Law, Mansun

2012-04-17

Hepatitis C virus (HCV) infects ∼2% of the world's population. It is estimated that there are more than 500,000 new infections annually in Egypt, the country with the highest HCV prevalence. An effective vaccine would help control this expanding global health burden. HCV is highly variable, and an effective vaccine should target conserved T- and B-cell epitopes of the virus. Conserved B-cell epitopes overlapping the CD81 receptor-binding site (CD81bs) on the E2 viral envelope glycoprotein have been reported previously and provide promising vaccine targets. In this study, we isolated 73 human mAbs recognizing five distinct antigenic regions on the virus envelope glycoprotein complex E1E2 from an HCV-immune phage-display antibody library by using an exhaustive-panning strategy. Many of these mAbs were broadly neutralizing. In particular, the mAb AR4A, recognizing a discontinuous epitope outside the CD81bs on the E1E2 complex, has an exceptionally broad neutralizing activity toward diverse HCV genotypes and protects against heterologous HCV challenge in a small animal model. The mAb panel will be useful for the design and development of vaccine candidates to elicit broadly neutralizing antibodies to HCV.

Therapeutic vaccines in HBV: lessons from HCV.

PubMed

Barnes, Eleanor

2015-02-01

Currently, millions of people infected with hepatitis B virus (HBV) are committed to decades of treatment with anti-viral therapy to control viral replication. However, new tools for immunotherapy that include both viral vectors and molecular checkpoint inhibitors are now available. This has led to a resurgence of interest in new strategies to develop immunotherapeutic strategies with the aim of inducing HBeAg seroconversion--an end-point that has been associated with a decrease in the rates of disease progression. Ultimately, a true cure will involve the elimination of covalently closed circular DNA which presents a greater challenge for immunotherapy. In this manuscript, I describe the development of immunotherapeutic strategies for HBV that are approaching or currently in clinical studies, and draw on observations of T cell function in natural infection supported by recent animal studies that may lead to additional rational vaccine strategies using checkpoint inhibitors. I also draw on our recent experience in developing potent vaccines for HCV prophylaxis based on simian adenoviral and MVA vectors used in prime-boost strategies in both healthy volunteers and HCV infected patients. I have shown that the induction of T cell immune responses is markedly attenuated when administered to people with persistent HCV viremia. These studies and recently published animal studies using the woodchuck model suggest that potent vaccines based on DNA or adenoviral vectored vaccination represent a rational way forward. However, combining these with drugs to suppress viral replication, alongside checkpoint inhibitors may be required to induce long-term immune control.

Performance evaluation of the Aptima® HCV Quant Dx assay for hepatitis C virus (HCV) RNA detection and quantification in comparison to the Abbott RealTime HCV assay.

PubMed

Garbuglia, Anna Rosa; Bibbò, Angela; Sciamanna, Roberta; Pisciotta, Marina; Capobianchi, Maria Rosaria

2017-07-01

The Aptima HCV Quant Dx assay (Aptima) is a real-time transcription-mediated amplification assay CE-approved for the diagnosis and monitoring of hepatitis C virus (HCV) infection. Aptima's analytical performance was compared to the Abbott RealTime HCV assay (RealTime) in a clinical routine setting. Overall 295 clinical plasma samples (117 prospective/fresh; 178 retrospective/frozen) from HCV-infected patients were tested in Aptima and RealTime to determine concordance on qualitative and quantitative results. Linearity and precision at low viral loads (VLs; 0.8-3.3LogIU/mL) was tested using dilutions of the 5th WHO standard, in 10 and 20 replicates in the two assays, respectively. The ability to measure different HCV genotypes and accuracy were analyzed using the Seracare EQA panel. Inter-assay agreement for qualitative results (prospective samples) was 88% (kappa=0.78). For the 127 samples with quantitative results in both assays, Aptima yielded on average slightly higher values (by 0.24LogIU/mL; Bland-Altman method) than RealTime. Concordance between assay results was excellent (R=0.98). At low VLs (0.8-3.3LogIU/mL), Aptima demonstrated good linearity and precision, similar to RealTime. Aptima detected and accurately quantified all main HCV genotypes. Aptima demonstrated excellent precision, linearity, and accuracy in all genotypes tested. Good concordance was observed between Aptima and RealTime assays in clinical samples. The performance of the Aptima assay, on the fully automated Panther platform, makes it an excellent candidate for the detection and monitoring of HCV RNA in plasma and serum samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Logical Analysis of Regulation of Interleukin-12 Expression Pathway Regulation During HCV Infection.

PubMed

Farooqi, Zia-Ur-Rehman; Tareen, Samar H K; Ahmed, Jamil; Zaidi, Najam-Us-Sahar S

2016-01-01

Hepatitis C virus (HCV) triggers coordinated innate and adaptive response in host cell. HCV genome and proteins of the replicating virus are recognized as non-self-antigens by host cell to activate Toll Like Receptors (TLRs). Activated TLRs ultimately express cytokines, which can clear virus either by activating interferon (IFN), protein kinase C (PKC) and RNA Lase system or through activation of cytotoxic T-lymphocytes. Interleukin-12 (IL-12) is a potent antiviral cytokine, capable of clearing HCV by bridging both innate and adaptive antiviral immune response. Activation of TLR-4 on macrophages surface induces expression of IL-12 via NF-κB and AP-1 transcriptional pathway. After expression, IL- 12 releases IFN-γ, which activates anti-HCV cytotoxic lymphocytes. Conversely, in chronic HCV infection downregulation of IL-12 has been reported instead of by number of studies. Keeping in view of the above mentioned facts, this study was designed to evaluate HCV-core mediated down-regulation of IL-12 transcriptional pathway by employing a logical modeling approach based on the Ren´e Thomas formalism. The logical parameters of entities were estimated by using SMBioNet. The Logical model represents all possible dynamics of protein expression involved during course of HCV pathology. Results demonstrated that at chronic stage of infection, though TLR-4 was constantly active but yet it failed to express the NF-κB, AP-1, IL-12 and IFN-γ. This mechanism was indicative of incorporation of core mediated changes in IL-12 regulatory pathway. Moreover, results also indicate that HCV adopts different trajectories to accomplish the persistence of chronic phase of infection. It also implicated that human immune system tries to clear HCV but core is capable of inducing system oscillations to evade the immunity.

Hepatitis B and C coinfection in a real-life setting: viral interactions and treatment issues.

PubMed

Papadopoulos, Nikolaos; Papavdi, Maria; Pavlidou, Anna; Konstantinou, Dimitris; Kranidioti, Hariklia; Kontos, George; Koskinas, John; Papatheodoridis, George V; Manolakopoulos, Spilios; Deutsch, Melanie

2018-01-01

Only limited data concerning hepatitis B (HBV) and C viruses (HCV) coinfection are available. Direct-acting antivirals (DAAs) may be more effective for HCV clearance than interferon (IFN)-based regimens with a risk of HBV reactivation. We retrospectively enrolled 40 HBV/HCV-coinfected patients to evaluate their clinical profile and treatment outcomes. Chronic dual infection was present in 25/40 (62.5%) patients, acute HCV superinfection in 5/40 (12.5%) patients and acute HBV superinfection in 10/40 (25%). Twenty-five patients (62.5%) were treated: 16/25 (64%) with IFN, 4/25 (16%) with nucleot(s)ide analogs (NUCs) and 5/25 (20%) with DAAs. Of the 16 patients treated with IFN-based therapy, 6 (37.5%) achieved both sustained virological response (SVR) and HBsAg clearance. Of the 4 patients treated with NUCs, one (25%) achieved both SVR and HBsAg clearance. All five patients treated with DAAs (100%) achieved SVR, while one case of HBV reactivation was recorded. Fifteen of the 40 patients (37.5%) did not receive any treatment. Eight of them (53.5%) presented with acute HBV superinfection: spontaneous HCV clearance was recorded in 5/8 (62.5%), while HBsAg clearance occurred in 6/8 (75%). Three of them (20%) presented with acute HCV superinfection; spontaneous HCV clearance was recorded in one of the three (33.5%). The other four patients (26.5%) presented with dual HBV/HCV infection. A significant proportion of patients presented with active HBV replication. Treatment with DAAs seems to be efficacious for HCV eradication. However, clinicians should be aware of HBV reactivation. HBV superinfection may lead to both HBsAg and HCV clearance.

Apolipoprotein B100 is required for hepatitis C infectivity and Mipomersen inhibits hepatitis C

PubMed Central

Schaefer, Esperance A K; Meixiong, James; Mark, Christina; Deik, Amy; Motola, Daniel L; Fusco, Dahlene; Yang, Andrew; Brisac, Cynthia; Salloum, Shadi; Lin, Wenyu; Clish, Clary B; Peng, Lee F; Chung, Raymond T

2016-01-01

AIM To characterize the role of apolipoprotein B100 (apoB100) in hepatitis C viral (HCV) infection. METHODS In this study, we utilize a gene editing tool, transcription activator-like effector nucleases (TALENs), to generate human hepatoma cells with a stable genetic deletion of APOB to assess of apoB in HCV. Using infectious cell culture-competent HCV, viral pseudoparticles, replicon models, and lipidomic analysis we determined the contribution of apoB to each step of the viral lifecycle. We further studied the effect of mipomersen, an FDA-approved antisense inhibitor of apoB100, on HCV using in vitro cell-culture competent HCV and determined its impact on viral infectivity with the TCID50 method. RESULTS We found that apoB100 is indispensable for HCV infection. Using the JFH-1 fully infectious cell-culture competent virus in Huh 7 hepatoma cells with TALEN-mediated gene deletion of apoB (APOB KO), we found a significant reduction in HCV RNA and protein levels following infection. Pseudoparticle and replicon models demonstrated that apoB did not play a role in HCV entry or replication. However, the virus produced by APOB KO cells had significantly diminished infectivity as measured by the TCID-50 method compared to wild-type virus. Lipidomic analysis demonstrated that these virions have a fundamentally altered lipidome, with complete depletion of cholesterol esters. We further demonstrate that inhibition of apoB using mipomersen, an FDA-approved anti-sense oligonucleotide, results in a potent anti-HCV effect and significantly reduces the infectivity of the virus. CONCLUSION ApoB is required for the generation of fully infectious HCV virions, and inhibition of apoB with mipomersen blocks HCV. Targeting lipid metabolic pathways to impair viral infectivity represents a novel host targeted strategy to inhibit HCV. PMID:28018102

Structural flexibility of a conserved antigenic region in hepatitis C virus glycoprotein E2 recognized by broadly neutralizing antibodies.

PubMed

Meola, Annalisa; Tarr, Alexander W; England, Patrick; Meredith, Luke W; McClure, C Patrick; Foung, Steven K H; McKeating, Jane A; Ball, Jonathan K; Rey, Felix A; Krey, Thomas

2015-02-01

Neutralizing antibodies (NAbs) targeting glycoprotein E2 are important for the control of hepatitis C virus (HCV) infection. One conserved antigenic site (amino acids 412 to 423) is disordered in the reported E2 structure, but a synthetic peptide mimicking this site forms a β-hairpin in complex with three independent NAbs. Our structure of the same peptide in complex with NAb 3/11 demonstrates a strikingly different extended conformation. We also show that residues 412 to 423 are essential for virus entry but not for E2 folding. Together with the neutralizing capacity of the 3/11 Fab fragment, this indicates an unexpected structural flexibility within this epitope. NAbs 3/11 and AP33 (recognizing the extended and β-hairpin conformations, respectively) display similar neutralizing activities despite converse binding kinetics. Our results suggest that HCV utilizes conformational flexibility as an immune evasion strategy, contributing to the limited immunogenicity of this epitope in patients, similar to the conformational flexibility described for other enveloped and nonenveloped viruses. Approximately 180 million people worldwide are infected with hepatitis C virus (HCV), and neutralizing antibodies play an important role in controlling the replication of this major human pathogen. We show here that one of the most conserved antigenic sites within the major glycoprotein E2 (amino acids 412 to 423), which is disordered in the recently reported crystal structure of an E2 core fragment, can adopt different conformations in the context of the infectious virus particle. Recombinant Fab fragments recognizing different conformations of this antigenic site have similar neutralization activities in spite of converse kinetic binding parameters. Of note, an antibody response targeting this antigenic region is less frequent than those targeting other more immunogenic regions in E2. Our results suggest that the observed conformational flexibility in this conserved antigenic region contributes to the evasion of the humoral host immune response, facilitating chronicity and the viral spread of HCV within an infected individual. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Studies of Antiviral Activity and Cytotoxicity of Wrightia tinctoria and Morinda citrifolia

PubMed Central

Selvam, P.; Murugesh, N.; Witvrouw, M.; Keyaerts, E.; Neyts, J.

2009-01-01

Different extracts of leaf parts of Wrightia tinctoria and fruit powder of Morinda citrifolia have been studied against replication of HIV-1(IIIB) in MT-4 cells and HCV in Huh 5.2 cells. Chloroform extract of Wrightia tinctoria exhibited a maximum protection of 48% against the cytopathic effect of HIV-1(IIIB) in MT-4 cells. Fruit juice of Morinda citrifolia exhibited a displayed marked cytotoxic activity in lymphocyte (MT-4) cells (CC50: 0.19 mg/ml). The 50% effective concentration for inhibition of HCV subgenomic replicon replication in Huh 5-2 cells by Morinda citrifolia was 0.98 μg/ml and by chloroform extract of Wrightia tinctoria was 10 μg/ml. The concentration that reduced the growth of exponentially proliferating Huh 5-2 cells by 50% was greater than 50 μg/ml. PMID:20376221

Structure-based discovery of pyrazolobenzothiazine derivatives as inhibitors of hepatitis C virus replication

PubMed Central

Barreca, Maria Letizia; Manfroni, Giuseppe; Leyssen, Pieter; Winquist, Johan; Kaushik-Basu, Neerja; Paeshuyse, Jan; Krishnan, Ramalingam; Iraci, Nunzio; Sabatini, Stefano; Tabarrini, Oriana; Basu, Amartya; Danielson, U. Helena; Neyts, Johan; Cecchetti, Violetta

2013-01-01

The NS5B RNA-dependent RNA polymerase is an attractive target for the development of novel and selective inhibitors of hepatitis C virus replication. In order to identify novel structural hits as anti-HCV agents, we performed structure-based virtual screening of our in-house library followed by rational drug design, organic synthesis and biological testing. These studies led to the identification of pyrazolobenzothiazine scaffold as a suitable template for obtaining novel anti-HCV agents targeting the NS5B polymerase. The best compound of this series was the meta-fluoro-N-1-phenyl pyrazolobenzothiazine derivative 4a, which exhibited an EC50= 3.6 µM, EC90= 25.6 µM and CC50 > 180 µM in the Huh 9–13 replicon system, thus providing a good starting point for further hit evolution. PMID:23409936

Landscape of post-transcriptional gene regulation during hepatitis C virus infection

PubMed Central

Schwerk, Johannes; Jarret, Abigail P.; Joslyn, Rochelle C.; Savan, Ram

2015-01-01

Post-transcriptional regulation of gene expression plays a pivotal role in various gene regulatory networks including, but not limited to metabolism, embryogenesis and immune responses. Different mechanisms of post-transcriptional regulation, which can act individually, synergistically, or even in an antagonistic manner have been described. Hepatitis C virus (HCV) is notorious for subverting host immune responses and indeed exploits several components of the host’s post-transcriptional regulatory machinery for its own benefit. At the same time, HCV replication is post-transcriptionally targeted by host cell components to blunt viral propagation. This review discusses the interplay of post-transcriptional mechanisms that affect host immune responses in the setting of HCV infection and highlights the sophisticated mechanisms both host and virus have evolved in the race for superiority. PMID:25890065

In vivo therapeutic potential of Dicer-hunting siRNAs targeting infectious hepatitis C virus.

PubMed

Watanabe, Tsunamasa; Hatakeyama, Hiroto; Matsuda-Yasui, Chiho; Sato, Yusuke; Sudoh, Masayuki; Takagi, Asako; Hirata, Yuichi; Ohtsuki, Takahiro; Arai, Masaaki; Inoue, Kazuaki; Harashima, Hideyoshi; Kohara, Michinori

2014-04-23

The development of RNA interference (RNAi)-based therapy faces two major obstacles: selecting small interfering RNA (siRNA) sequences with strong activity, and identifying a carrier that allows efficient delivery to target organs. Additionally, conservative region at nucleotide level must be targeted for RNAi in applying to virus because hepatitis C virus (HCV) could escape from therapeutic pressure with genome mutations. In vitro preparation of Dicer-generated siRNAs targeting a conserved, highly ordered HCV 5' untranslated region are capable of inducing strong RNAi activity. By dissecting the 5'-end of an RNAi-mediated cleavage site in the HCV genome, we identified potent siRNA sequences, which we designate as Dicer-hunting siRNAs (dh-siRNAs). Furthermore, formulation of the dh-siRNAs in an optimized multifunctional envelope-type nano device inhibited ongoing infectious HCV replication in human hepatocytes in vivo. Our efforts using both identification of optimal siRNA sequences and delivery to human hepatocytes suggest therapeutic potential of siRNA for a virus.

Hepatitis C Virus Proteins Interact with the Endosomal Sorting Complex Required for Transport (ESCRT) Machinery via Ubiquitination To Facilitate Viral Envelopment

PubMed Central

Barouch-Bentov, Rina; Neveu, Gregory; Xiao, Fei; Beer, Melanie; Bekerman, Elena; Schor, Stanford; Campbell, Joseph; Boonyaratanakornkit, Jim; Lindenbach, Brett; Lu, Albert; Jacob, Yves

2016-01-01

ABSTRACT Enveloped viruses commonly utilize late-domain motifs, sometimes cooperatively with ubiquitin, to hijack the endosomal sorting complex required for transport (ESCRT) machinery for budding at the plasma membrane. However, the mechanisms underlying budding of viruses lacking defined late-domain motifs and budding into intracellular compartments are poorly characterized. Here, we map a network of hepatitis C virus (HCV) protein interactions with the ESCRT machinery using a mammalian-cell-based protein interaction screen and reveal nine novel interactions. We identify HRS (hepatocyte growth factor-regulated tyrosine kinase substrate), an ESCRT-0 complex component, as an important entry point for HCV into the ESCRT pathway and validate its interactions with the HCV nonstructural (NS) proteins NS2 and NS5A in HCV-infected cells. Infectivity assays indicate that HRS is an important factor for efficient HCV assembly. Specifically, by integrating capsid oligomerization assays, biophysical analysis of intracellular viral particles by continuous gradient centrifugations, proteolytic digestion protection, and RNase digestion protection assays, we show that HCV co-opts HRS to mediate a late assembly step, namely, envelopment. In the absence of defined late-domain motifs, K63-linked polyubiquitinated lysine residues in the HCV NS2 protein bind the HRS ubiquitin-interacting motif to facilitate assembly. Finally, ESCRT-III and VPS/VTA1 components are also recruited by HCV proteins to mediate assembly. These data uncover involvement of ESCRT proteins in intracellular budding of a virus lacking defined late-domain motifs and a novel mechanism by which HCV gains entry into the ESCRT network, with potential implications for other viruses. PMID:27803188

Hepatitis-C-virus-like internal ribosome entry sites displace eIF3 to gain access to the 40S subunit

NASA Astrophysics Data System (ADS)

Hashem, Yaser; Des Georges, Amedee; Dhote, Vidya; Langlois, Robert; Liao, Hstau Y.; Grassucci, Robert A.; Pestova, Tatyana V.; Hellen, Christopher U. T.; Frank, Joachim

2013-11-01

Hepatitis C virus (HCV) and classical swine fever virus (CSFV) messenger RNAs contain related (HCV-like) internal ribosome entry sites (IRESs) that promote 5'-end independent initiation of translation, requiring only a subset of the eukaryotic initiation factors (eIFs) needed for canonical initiation on cellular mRNAs. Initiation on HCV-like IRESs relies on their specific interaction with the 40S subunit, which places the initiation codon into the P site, where it directly base-pairs with eIF2-bound initiator methionyl transfer RNA to form a 48S initiation complex. However, all HCV-like IRESs also specifically interact with eIF3 (refs 2, 5, 6, 7, 9, 10, 11, 12), but the role of this interaction in IRES-mediated initiation has remained unknown. During canonical initiation, eIF3 binds to the 40S subunit as a component of the 43S pre-initiation complex, and comparison of the ribosomal positions of eIF3 and the HCV IRES revealed that they overlap, so that their rearrangement would be required for formation of ribosomal complexes containing both components. Here we present a cryo-electron microscopy reconstruction of a 40S ribosomal complex containing eIF3 and the CSFV IRES. Remarkably, although the position and interactions of the CSFV IRES with the 40S subunit in this complex are similar to those of the HCV IRES in the 40S-IRES binary complex, eIF3 is completely displaced from its ribosomal position in the 43S complex, and instead interacts through its ribosome-binding surface exclusively with the apical region of domain III of the IRES. Our results suggest a role for the specific interaction of HCV-like IRESs with eIF3 in preventing ribosomal association of eIF3, which could serve two purposes: relieving the competition between the IRES and eIF3 for a common binding site on the 40S subunit, and reducing formation of 43S complexes, thereby favouring translation of viral mRNAs.

Hepatitis C Virus Proteins Interact with the Endosomal Sorting Complex Required for Transport (ESCRT) Machinery via Ubiquitination To Facilitate Viral Envelopment.

PubMed

Barouch-Bentov, Rina; Neveu, Gregory; Xiao, Fei; Beer, Melanie; Bekerman, Elena; Schor, Stanford; Campbell, Joseph; Boonyaratanakornkit, Jim; Lindenbach, Brett; Lu, Albert; Jacob, Yves; Einav, Shirit

2016-11-01

Enveloped viruses commonly utilize late-domain motifs, sometimes cooperatively with ubiquitin, to hijack the endosomal sorting complex required for transport (ESCRT) machinery for budding at the plasma membrane. However, the mechanisms underlying budding of viruses lacking defined late-domain motifs and budding into intracellular compartments are poorly characterized. Here, we map a network of hepatitis C virus (HCV) protein interactions with the ESCRT machinery using a mammalian-cell-based protein interaction screen and reveal nine novel interactions. We identify HRS (hepatocyte growth factor-regulated tyrosine kinase substrate), an ESCRT-0 complex component, as an important entry point for HCV into the ESCRT pathway and validate its interactions with the HCV nonstructural (NS) proteins NS2 and NS5A in HCV-infected cells. Infectivity assays indicate that HRS is an important factor for efficient HCV assembly. Specifically, by integrating capsid oligomerization assays, biophysical analysis of intracellular viral particles by continuous gradient centrifugations, proteolytic digestion protection, and RNase digestion protection assays, we show that HCV co-opts HRS to mediate a late assembly step, namely, envelopment. In the absence of defined late-domain motifs, K63-linked polyubiquitinated lysine residues in the HCV NS2 protein bind the HRS ubiquitin-interacting motif to facilitate assembly. Finally, ESCRT-III and VPS/VTA1 components are also recruited by HCV proteins to mediate assembly. These data uncover involvement of ESCRT proteins in intracellular budding of a virus lacking defined late-domain motifs and a novel mechanism by which HCV gains entry into the ESCRT network, with potential implications for other viruses. Viruses commonly bud at the plasma membrane by recruiting the host ESCRT machinery via conserved motifs termed late domains. The mechanism by which some viruses, such as HCV, bud intracellularly is, however, poorly characterized. Moreover, whether envelopment of HCV and other viruses lacking defined late domains is ESCRT mediated and, if so, what the entry points into the ESCRT pathway are remain unknown. Here, we report the interaction network of HCV with the ESCRT machinery and a critical role for HRS, an ESCRT-0 complex component, in HCV envelopment. Viral protein ubiquitination was discovered to be a signal for HRS binding and HCV assembly, thereby functionally compensating for the absence of late domains. These findings characterize how a virus lacking defined late domains co-opts ESCRT to bud intracellularly. Since the ESCRT machinery is essential for the life cycle of multiple viruses, better understanding of this virus-host interplay may yield targets for broad-spectrum antiviral therapies. Copyright © 2016 Barouch-Bentov et al.

Establishment of a Novel Permissive Cell Line for the Propagation of Hepatitis C Virus by Expression of MicroRNA miR122

PubMed Central

Kambara, Hiroto; Fukuhara, Takasuke; Shiokawa, Mai; Ono, Chikako; Ohara, Yuri; Kamitani, Wataru

2012-01-01

The robust cell culture systems for hepatitis C virus (HCV) are limited to those using cell culture-adapted clones (HCV in cell culture [HCVcc]) and cells derived from the human hepatoma cell line Huh7. However, accumulating data suggest that host factors, including innate immunity and gene polymorphisms, contribute to the variation in host response to HCV infection. Therefore, the existing in vitro systems for HCV propagation are not sufficient to elucidate the life cycle of HCV. A liver-specific microRNA, miR122, has been shown to participate in the efficient replication of HCV. In this study, we examined the possibility of establishing a new permissive cell line for HCV propagation by the expression of miR122. A high level of miR122 was expressed by a lentiviral vector placed into human liver cell lines at a level comparable to the endogenous level in Huh7 cells. Among the cell lines that we examined, Hep3B cells stably expressing miR122 (Hep3B/miR122) exhibited a significant enhancement of HCVcc propagation. Surprisingly, the levels of production of infectious particles in Hep3B/miR122 cells upon infection with HCVcc were comparable to those in Huh7 cells. Furthermore, a line of “cured” cells, established by elimination of HCV RNA from the Hep3B/miR122 replicon cells, exhibited an enhanced expression of miR122 and a continuous increase of infectious titers of HCVcc in every passage. The establishment of the new permissive cell line for HCVcc will have significant implications not only for basic HCV research but also for the development of new therapeutics. PMID:22114337

[Effect of Hepatitis C virus proteins on the production of proinflammatory and profibrotic cytokines in Huh7.5 human hepatoma cells].

PubMed

Masalova, O V; Lesnova, E I; Permyakova, K Yu; Samokhvalov, E I; Ivanov, A V; Kochetkov, S N; Kushch, A A

2016-01-01

Hepatitis C virus (HCV) is a widespread dangerous human pathogen. Up to 80% of HCV-infected individuals develop chronic infection, which is often accompanied by liver inflammation and fibrosis and, at terminal stages, liver cirrhosis and cancer. Treatment of patients with end-stage liver disease is often ineffective, and even patients with suppressed HCV replication have higher risk of death as compared with noninfected subjects. Therefore, investigating the mechanisms that underlie HCV pathogenesis and developing treatments for virus-associated liver dysfunction remain an important goal. The effect of individual HCV proteins on the production of proinflammatory and profibrotic cytokines in hepatocellular carcinoma Huh7.5 cells was analyzed in a systematic manner. Cells were transfected with plasmids encoding HCV proteins. Cytokine production and secretion was accessed by immunocytochemistry and ELISA of the culture medium, and transcription of the cytokine genes was assessed using reverse transcription and PCR. HCV proteins proved to differ in effect on cytokine production. Downregulation of interleukin 6 (IL-6) production was observed in cells expressing the HCV core, NS3, and NS5A proteins. Production of transforming growth factor β1 (TGF-β1) was lower in cells expressing the core proteins, NS3, or E1/E2 glycoproteins. A pronounced increase in production and secretion of tumor necrosis factor α (TNF-α) was observed in response to expression of the HCV E1/E2 glycoproteins. A higher biosynthesis, but a lower level in the cell culture medium, was detected for interleukin 1β (IL-1β) in cells harboring NS4 and IL-6 in cells expressing NS5В. The finding was possibly explained by protein-specific retention and consequent accumulation of the respective cytokines in the cell.

Establishment of chronic hepatitis C virus infection: Translational evasion of oxidative defence

PubMed Central

Chan, Shiu-Wan

2014-01-01

Hepatitis C virus (HCV) causes a clinically important disease affecting 3% of the world population. HCV is a single-stranded, positive-sense RNA virus belonging to the genus Hepacivirus within the Flaviviridae family. The virus establishes a chronic infection in the face of an active host oxidative defence, thus adaptation to oxidative stress is key to virus survival. Being a small RNA virus with a limited genomic capacity, we speculate that HCV deploys a different strategy to evade host oxidative defence. Instead of counteracting oxidative stress, it utilizes oxidative stress to facilitate its own survival. Translation is the first step in the replication of a plus strand RNA virus so it would make sense if the virus can exploit the host oxidative defence in facilitating this very first step. This is particularly true when HCV utilizes an internal ribosome entry site element in translation, which is distinctive from that of cap-dependent translation of the vast majority of cellular genes, thus allowing selective translation of genes under conditions when global protein synthesis is compromised. Indeed, we were the first to show that HCV translation was stimulated by an important pro-oxidant-hydrogen peroxide in hepatocytes, suggesting that HCV is able to adapt to and utilize the host anti-viral response to facilitate its own translation thus allowing the virus to thrive under oxidative stress condition to establish chronicity. Understanding how HCV translation is regulated under oxidative stress condition will advance our knowledge on how HCV establishes chronicity. As chronicity is the initiator step in disease progression this will eventually lead to a better understanding of pathogenicity, which is particularly relevant to the development of anti-virals and improved treatments of HCV patients using anti-oxidants. PMID:24659872

Genome-Wide Association Study Identifies Risk Variants for Lichen Planus in Patients With Hepatitis C Virus Infection.

PubMed

Nagao, Yumiko; Nishida, Nao; Toyo-Oka, Licht; Kawaguchi, Atsushi; Amoroso, Antonio; Carrozzo, Marco; Sata, Michio; Mizokami, Masashi; Tokunaga, Katsushi; Tanaka, Yasuhito

2017-06-01

There is a close relationship between hepatitis C virus (HCV) infection and lichen planus, a chronic inflammatory mucocutaneous disease. We performed a genome-wide association study (GWAS) to identify genetic variants associated with HCV-related lichen planus. We conducted a GWAS of 261 patients with HCV infection treated at a tertiary medical center in Japan from October 2007 through January 2013; a total of 71 had lichen planus and 190 had normal oral mucosa. We validated our findings in a GWAS of 38 patients with HCV-associated lichen planus and 7 HCV-infected patients with normal oral mucosa treated at a medical center in Italy. Single-nucleotide polymorphisms in NRP2 (rs884000) and IGFBP4 (rs538399) were associated with risk of HCV-associated lichen planus (P < 1 × 10 -4 ). We also found an association between a single-nucleotide polymorphism in the HLA-DR/DQ genes (rs9461799) and susceptibility to HCV-associated lichen planus. The odds ratios for the minor alleles of rs884000, rs538399, and rs9461799 were 3.25 (95% confidence interval, 1.95-5.41), 0.40 (95% confidence interval, 0.25-0.63), and 2.15 (95% confidence interval, 1.41-3.28), respectively. In a GWAS of Japanese patients with HCV infection, we replicated associations between previously reported polymorphisms in HLA class II genes and risk for lichen planus. We also identified single-nucleotide polymorphisms in NRP2 and IGFBP4 loci that increase and reduce risk of lichen planus, respectively. These genetic variants might be used to identify patients with HCV infection who are at risk for lichen planus. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Prevalence of Diagnosed and Undiagnosed Hepatitis C in a Midwestern Urban Emergency Department.

PubMed

Lyons, Michael S; Kunnathur, Vidhya A; Rouster, Susan D; Hart, Kimberly W; Sperling, Matthew I; Fichtenbaum, Carl J; Sherman, Kenneth E

2016-05-01

Targeted hepatitis C virus (HCV) screening is recommended. Implementation of screening in emergency department (ED) settings is challenging and controversial. Understanding HCV epidemiology in EDs could motivate and guide screening efforts. We characterized the prevalence of diagnosed and undiagnosed HCV in a Midwestern, urban ED. This was a cross-sectional seroprevalence study using de-identified blood samples and self-reported health information obtained from consecutively approached ED patients aged 18-64 years. Subjects consented to a "study of diseases of public health importance" and were compensated for participation. The Biochain ELISA kit for Human Hepatitis C Virus was used for antibody assay. Viral RNA was isolated using the Qiagen QIAamp UltraSens Virus kit, followed by real-time reverse transcription polymerase chain reaction using a Bio-Rad CFX96 SYBR Green UltraFast program with melt-curve analysis. HCV antibody was detected in 128 of 924 (14%; 95% confidence interval [CI], 12%-16%) samples. Of these, 44 (34%) self-reported a history of HCV or hepatitis of unknown type and 103 (81%; 95% CI, 73%-87%) were RNA positive. Two additional patients were antibody negative but RNA positive. Fully implemented birth cohort screening for HCV antibody would have missed 36 of 128 (28%) of cases with detectable antibody and 26 of 105 (25%) of those with replicative HCV infection. HCV infection is highly prevalent in EDs. Emergency departments are likely to be uniquely important for HCV screening, and logistical challenges to ED screening should be overcome. Birth cohort screening would have missed many patients, suggesting the need for complementary screening strategies applied to an expanded age range. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Cryo-EM structure of Hepatitis C virus IRES bound to the human ribosome at 3.9-Å resolution

NASA Astrophysics Data System (ADS)

Quade, Nick; Boehringer, Daniel; Leibundgut, Marc; van den Heuvel, Joop; Ban, Nenad

2015-07-01

Hepatitis C virus (HCV), a widespread human pathogen, is dependent on a highly structured 5'-untranslated region of its mRNA, referred to as internal ribosome entry site (IRES), for the translation of all of its proteins. The HCV IRES initiates translation by directly binding to the small ribosomal subunit (40S), circumventing the need for many eukaryotic translation initiation factors required for mRNA scanning. Here we present the cryo-EM structure of the human 40S ribosomal subunit in complex with the HCV IRES at 3.9 Å resolution, determined by focused refinement of an 80S ribosome-HCV IRES complex. The structure reveals the molecular details of the interactions between the IRES and the 40S, showing that expansion segment 7 (ES7) of the 18S rRNA acts as a central anchor point for the HCV IRES. The structural data rationalizes previous biochemical and genetic evidence regarding the initiation mechanism of the HCV and other related IRESs.

Downregulation of viral RNA translation by hepatitis C virus non-structural protein NS5A requires the poly(U/UC) sequence in the 3' UTR.

PubMed

Hoffman, Brett; Li, Zhubing; Liu, Qiang

2015-08-01

Hepatitis C virus (HCV) non-structural protein 5A (NS5A) is essential for viral replication; however, its effect on HCV RNA translation remains controversial partially due to the use of reporters lacking the 3' UTR, where NS5A binds to the poly(U/UC) sequence. We investigated the role of NS5A in HCV translation using a monocistronic RNA containing a Renilla luciferase gene flanked by the HCV UTRs. We found that NS5A downregulated viral RNA translation in a dose-dependent manner. This downregulation required both the 5' and 3' UTRs of HCV because substitution of either sequence with the 5' and 3' UTRs of enterovirus 71 or a cap structure at the 5' end eliminated the effects of NS5A on translation. Translation of the HCV genomic RNA was also downregulated by NS5A. The inhibition of HCV translation by NS5A required the poly(U/UC) sequence in the 3' UTR as NS5A did not affect translation when it was deleted. In addition, we showed that, whilst the amphipathic α-helix of NS5A has no effect on viral translation, the three domains of NS5A can inhibit translation independently, also dependent on the presence of the poly(U/UC) sequence in the 3' UTR. These results suggested that NS5A downregulated HCV RNA translation through a mechanism involving the poly(U/UC) sequence in the 3' UTR.

IL28B polymorphisms of both recipient and donor cooperate to influence IFN treatment response in HCV recurrence after liver transplantation, but IL28B SNPs of the recipient play a major role in IFN-induced blocking of HCV replication.

PubMed

Barbera, Floriana; Russelli, Giovanna; Pipitone, Loredana; Pietrosi, Giada; Corsale, Sveva; Vizzini, Giovanni; Gridelli, Bruno; Conaldi, Pier Giulio

2015-04-01

Single nucleotide polymorphisms (SNPs) of the IL28B locus are associated with a positive response to pegylated interferon-alpha and ribavirin (pegIFN-alpha/RBV) treatment of HCV-infected patients. This study evaluated the association between SNPs rs12980275, rs12979860 and rs8099917 and treatment outcome of HCV recurrent infection in HCV-positive patients who underwent liver transplant. We aimed to assess to what extent recipient and/or graft donor IL28B polymorphisms contribute to HCV clearance after transplantation influencing the response to the antiviral treatment. We found that the allele frequencies in donors were in agreement with the pattern expected in the European population. The frequency of favourable genotypes was significantly lower in recipients than in donors, reasonably because the recipients represented a group of patients affected by chronic Hepatitis C. Our study demonstrated that the positive outcome of the pegIFN-alpha/RBV treatment of HCV recurrence is associated with the co-presence of favourable genotypes of both donors and recipients. However, IL28B SNPs of the recipient seem to play a major role in this clinical setting. In particular, homozygosis of rs12979860 favourable genotype in recipients was associated with sustained virological response independently from the donor's genotype. Thus, identification of these SNPs may be useful to predict the response to IFN-based therapy of HCV recurrent infection in liver-transplanted patients.

Inferring Viral Dynamics in Chronically HCV Infected Patients from the Spatial Distribution of Infected Hepatocytes

DOE PAGES

Graw, Frederik; Balagopal, Ashwin; Kandathil, Abraham J.; ...

2014-11-13

Chronic liver infection by hepatitis C virus (HCV) is a major public health concern. Despite partly successful treatment options, several aspects of intrahepatic HCV infection dynamics are still poorly understood, including the preferred mode of viral propagation, as well as the proportion of infected hepatocytes. Answers to these questions have important implications for the development of therapeutic interventions. In this study, we present methods to analyze the spatial distribution of infected hepatocytes obtained by single cell laser capture microdissection from liver biopsy samples of patients chronically infected with HCV. By characterizing the internal structure of clusters of infected cells, wemore » are able to evaluate hypotheses about intrahepatic infection dynamics. We found that individual clusters on biopsy samples range in size from 4-50 infected cells. In addition, the HCV RNA content in a cluster declines from the cell that presumably founded the cluster to cells at the maximal cluster extension. These observations support the idea that HCV infection in the liver is seeded randomly (e.g. from the blood) and then spreads locally. Assuming that the amount of intracellular HCV RNA is a proxy for how long a cell has been infected, we estimate based on models of intracellular HCV RNA replication and accumulation that cells in clusters have been infected on average for less than a week. Further, we do not find a relationship between the cluster size and the estimated cluster expansion time. Lastly, our method represents a novel approach to make inferences about infection dynamics in solid tissues from static spatial data.« less

Inferring Viral Dynamics in Chronically HCV Infected Patients from the Spatial Distribution of Infected Hepatocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graw, Frederik; Balagopal, Ashwin; Kandathil, Abraham J.

Chronic liver infection by hepatitis C virus (HCV) is a major public health concern. Despite partly successful treatment options, several aspects of intrahepatic HCV infection dynamics are still poorly understood, including the preferred mode of viral propagation, as well as the proportion of infected hepatocytes. Answers to these questions have important implications for the development of therapeutic interventions. In this study, we present methods to analyze the spatial distribution of infected hepatocytes obtained by single cell laser capture microdissection from liver biopsy samples of patients chronically infected with HCV. By characterizing the internal structure of clusters of infected cells, wemore » are able to evaluate hypotheses about intrahepatic infection dynamics. We found that individual clusters on biopsy samples range in size from 4-50 infected cells. In addition, the HCV RNA content in a cluster declines from the cell that presumably founded the cluster to cells at the maximal cluster extension. These observations support the idea that HCV infection in the liver is seeded randomly (e.g. from the blood) and then spreads locally. Assuming that the amount of intracellular HCV RNA is a proxy for how long a cell has been infected, we estimate based on models of intracellular HCV RNA replication and accumulation that cells in clusters have been infected on average for less than a week. Further, we do not find a relationship between the cluster size and the estimated cluster expansion time. Lastly, our method represents a novel approach to make inferences about infection dynamics in solid tissues from static spatial data.« less

Genotypic and Phenotypic Analyses of Hepatitis C Virus Variants Observed in Clinical Studies of VX-222, a Nonnucleoside NS5B Polymerase Inhibitor

PubMed Central

Zhang, Eileen Z.; Ardzinski, Andrzej; Tigges, Ann; Davis, Andrew; Sullivan, James C.; Nelson, Michelle; Spanks, Joan; Dorrian, Jennifer; Nicolas, Olivier; Bartels, Doug J.; Rao, B. Govinda; Rijnbrand, Rene; Kieffer, Tara L.

2014-01-01

VX-222, a thiophene-2-carboxylic acid derivative, is a selective nonnucleoside inhibitor of the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase. In phase 1 and 2 clinical studies, VX-222 demonstrated effective antiviral efficacy, with substantial reductions in plasma HCV RNA in patients chronically infected with genotype 1 HCV. To characterize the potential for selection of VX-222-resistant variants in HCV-infected patients, the HCV NS5B gene was sequenced at baseline and during and after 3 days of VX-222 dosing (monotherapy) in a phase 1 study. Variants with the substitutions L419C/I/M/P/S/V, R422K, M423I/T/V, I482L/N/T, A486S/T/V, and V494A were selected during VX-222 dosing, and their levels declined over time after the end of dosing. Phenotypic analysis of these variants was conducted using HCV replicons carrying site-directed mutations. Of the 17 variants, 14 showed reduced susceptibility to VX-222 compared with the wild type, with the L419C/S and R422K variants having higher levels of resistance (>200-fold) than the rest of the variants (6.8- to 76-fold). The M423I and A486S variants remained susceptible to VX-222. The 50% effective concentration (EC50) for the L419P variant could not be obtained due to the poor replication of this replicon. The majority of the variants (15/17) were less fit than the wild type. A subset of the variants, predominately the L419S and R422K variants, were observed when the efficacy and safety of VX-222- and telaprevir-based regimens given for 12 weeks were investigated in genotype 1 HCV-infected patients in a phase 2 study. The NS3 and NS5B variants selected during the dual combination therapy showed reduced susceptibility to both telaprevir and VX-222 and had a lower replication capacity than the wild type. The phase 1b study has the ClinicalTrials.gov identifier NCT00911963, and the phase 2a study has ClinicalTrials.gov identifier NCT01080222. PMID:24982088

Genotypic and phenotypic analyses of hepatitis C virus variants observed in clinical studies of VX-222, a nonnucleoside NS5B polymerase inhibitor.

PubMed

Jiang, Min; Zhang, Eileen Z; Ardzinski, Andrzej; Tigges, Ann; Davis, Andrew; Sullivan, James C; Nelson, Michelle; Spanks, Joan; Dorrian, Jennifer; Nicolas, Olivier; Bartels, Doug J; Rao, B Govinda; Rijnbrand, Rene; Kieffer, Tara L

2014-09-01

VX-222, a thiophene-2-carboxylic acid derivative, is a selective nonnucleoside inhibitor of the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase. In phase 1 and 2 clinical studies, VX-222 demonstrated effective antiviral efficacy, with substantial reductions in plasma HCV RNA in patients chronically infected with genotype 1 HCV. To characterize the potential for selection of VX-222-resistant variants in HCV-infected patients, the HCV NS5B gene was sequenced at baseline and during and after 3 days of VX-222 dosing (monotherapy) in a phase 1 study. Variants with the substitutions L419C/I/M/P/S/V, R422K, M423I/T/V, I482L/N/T, A486S/T/V, and V494A were selected during VX-222 dosing, and their levels declined over time after the end of dosing. Phenotypic analysis of these variants was conducted using HCV replicons carrying site-directed mutations. Of the 17 variants, 14 showed reduced susceptibility to VX-222 compared with the wild type, with the L419C/S and R422K variants having higher levels of resistance (>200-fold) than the rest of the variants (6.8- to 76-fold). The M423I and A486S variants remained susceptible to VX-222. The 50% effective concentration (EC50) for the L419P variant could not be obtained due to the poor replication of this replicon. The majority of the variants (15/17) were less fit than the wild type. A subset of the variants, predominately the L419S and R422K variants, were observed when the efficacy and safety of VX-222- and telaprevir-based regimens given for 12 weeks were investigated in genotype 1 HCV-infected patients in a phase 2 study. The NS3 and NS5B variants selected during the dual combination therapy showed reduced susceptibility to both telaprevir and VX-222 and had a lower replication capacity than the wild type. The phase 1b study has the ClinicalTrials.gov identifier NCT00911963, and the phase 2a study has ClinicalTrials.gov identifier NCT01080222. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

LncITPRIP-1 Positively Regulates Innate Immune Response through Promoting Oligomerization and Activation of MDA5.

PubMed

Xie, Qinya; Chen, Shengwen; Tian, Renyun; Huang, Xiang; Deng, Rilin; Xue, Binbin; Qin, Yuwen; Xu, Yan; Wang, Jingjing; Guo, Mengmeng; Chen, Jinwen; Tang, Songqing; Li, Guangdi; Zhu, Haizhen

2018-06-13

Emerging evidence indicates that long non-coding RNAs (lncRNAs) regulate various biological processes, especially innate and adaptive immunity. However, the relationship between lncRNAs and interferon (IFN) pathway remains largely unknown. Here, we report that lncRNA ITPRIP-1 (lncITPRIP-1) is involved in viral infection and plays a crucial role in virus-triggered IFN signaling pathway through targeting MDA5. LncITPRIP-1 can be induced by viral infection, which is not entirely dependent on IFN signal. Besides, there is no coding potential found in lncITPRIP-1 transcript. LncITPRIP-1 binds to the C-terminal of MDA5 and it possesses the ability to boost oligomerization of both full length and 2CARD domains of MDA5 in a K63-linked-polyubiquitination-independent manner. Amazingly, we also find that MDA5 could suppress HCV replication independent of IFN signaling through its C-terminal deficient domain bound to viral RNA, in which lncITPRIP-1 plays as an assistant. In addition, the expression of lncITPRIP-1 is highly consistent with MDA5 expression, indicating that lncITPRIP-1 may function as a cofactor of MDA5. All the data suggest that lncITPRIP-1 enhances innate immune response to viral infection through promoting oligomerization and activation of MDA5. Our study discovers the first lncRNA ITPRIP-1 involved in MDA5 activation. SIGNIFICANCE Hepatitis C virus infection causes a global health issue and there is still no available vaccine, which makes it urgent to reveal the underlying mechanisms of HCV and host factors. Although RIG-I has been recognized as the leading cytoplasmic sensor against HCV for a long time, recent findings of MDA5 regulating IFN response to HCV have emerged. Our work validates the significant role of MDA5 in IFN signaling and HCV infection, and proposes the first lncRNA inhibiting HCV replication by promoting the activation of MDA5 and mediating the association between MDA5 and HCV RNA, which may shed light on MDA5 function study and the treatment for hepatitis C patients. Our suggested model of how lncITPRIP-1 can orchestrate signal transduction for IFN production illustrates the essential role of lncRNAs in virus elimination. Copyright © 2018 American Society for Microbiology.

A Point Mutation in the N-Terminal Amphipathic Helix α0 in NS3 Promotes Hepatitis C Virus Assembly by Altering Core Localization to the Endoplasmic Reticulum and Facilitating Virus Budding

PubMed Central

Yan, Yu; He, Ying; Boson, Bertrand; Wang, Xuesong; Cosset, François-Loïc

2017-01-01

ABSTRACT The assembly of hepatitis C virus (HCV), a complicated process in which many viral and cellular factors are involved, has not been thoroughly deciphered. NS3 is a multifunctional protein that contains an N-terminal amphipathic α helix (designated helix α0), which is crucial for the membrane association and stability of NS3 protein, followed by a serine protease domain and a C-terminal helicase/NTPase domain. NS3 participates in HCV assembly likely through its C-terminal helicase domain, in which all reported adaptive mutations enhancing virion assembly reside. In this study, we determined that the N-terminal helix α0 of NS3 may contribute to HCV assembly. We identified a single mutation from methionine to threonine at amino acid position 21 (M21T) in helix α0, which significantly promoted viral production while having no apparent effect on the membrane association and protease activity of NS3. Subsequent analyses demonstrated that the M21T mutation did not affect HCV genome replication but rather promoted virion assembly. Further study revealed a shift in the subcellular localization of core protein from lipid droplets (LD) to the endoplasmic reticulum (ER). Finally, we showed that the M21T mutation increased the colocalization of core proteins and viral envelope proteins, leading to a more efficient envelopment of viral nucleocapsids. Collectively, the results of our study revealed a new function of NS3 helix α0 and aid understanding of the role of NS3 in HCV virion morphogenesis. IMPORTANCE HCV NS3 protein possesses the protease activity in its N-terminal domain and the helicase activity in its C-terminal domain. The role of NS3 in virus assembly has been mainly attributed to its helicase domain, because all adaptive mutations enhancing progeny virus production are found to be within this domain. Our study identified, for the first time to our knowledge, an adaptive mutation within the N-terminal helix α0 domain of NS3 that significantly enhanced virus assembly while having no effect on viral genome replication. The mechanistic studies suggested that this mutation promoted the relocation of core proteins from LD to the ER, leading to a more efficient envelopment of viral nucleocapsids. Our results revealed a possible new function of helix α0 in the HCV life cycle and provided new clues to understanding the molecular mechanisms for the action of NS3 in HCV assembly. PMID:28053108

Sustained Virological Response after 8-Week Treatment of Simeprevir with Peginterferon α-2a plus Ribavirin in a Japanese Female with Hepatitis C Virus Genotype 1b and IL28B Minor Genotype

PubMed Central

Kanda, Tatsuo; Nakamura, Masato; Sasaki, Reina; Yasui, Shin; Nakamoto, Shingo; Haga, Yuki; Jiang, Xia; Wu, Shuang; Tawada, Akinobu; Arai, Makoto; Imazeki, Fumio; Yokosuka, Osamu

2015-01-01

Direct-acting antivirals with or without peginterferon α (PEG-IFN α) plus ribavirin are now available for the treatment of hepatitis C virus (HCV) infection. Direct-acting antivirals are potent inhibitors of HCV replication, but some of them occasionally possess serious adverse events. We experienced a 64-year-old female with chronic HCV genotype 1b infection who showed elevated alanine aminotransferase of 528 IU/l at week 9 after the commencement of treatment of simeprevir with PEG-IFN α-2a plus ribavirin. However, she achieved sustained virological response at week 24 after the end of treatment. In Japan, we also have to treat elderly patients infected with HCV and/or advanced hepatic fibrosis. Until an effective interferon-free regimen is established, direct-acting antivirals with PEG-IFN plus ribavirin may still play a role in the treatment for certain patients. To avoid serious results from adverse events, careful attention and follow-up will be needed in the treatment course of simeprevir with PEG-IFN plus ribavirin for chronic HCV infection. PMID:26269697

Hepatitis C virus resistance to the new direct-acting antivirals.

PubMed

Esposito, Isabella; Trinks, Julieta; Soriano, Vicente

2016-10-01

The treatment of hepatitis C virus (HCV) infection has dramatically improved in recent years with the widespread use of interferon-free combination regimens. Despite the high sustained virological response (SVR) rates (over 90%) obtained with direct-acting antivirals (DAAs), drug resistance has emerged as a potential challenge. The high replication rate of HCV and the low fidelity of its RNA polymerase result in a high degree of genetic variability in the HCV population, which ultimately explains the rapid selection of drug resistance associated variants (RAVs). Results from clinical trials and real-world experience have both provided important information on the rate and clinical significance of RAVs. They can be present in treatment-naive patients as natural polymorphisms although more frequently they are selected upon treatment failure. In patients engaged in high-risk behaviors, RAVs can be transmitted. Although DAA failures generally occur in less than 10% of treated chronic hepatitis C patients, selection of drug resistance is the rule in most cases. HCV re-treatment options are available, but first-line therapeutic strategies should be optimized to efficiently prevent DAA failure due to baseline HCV resistance. Considerable progress is being made and next-generation DAAs are coming with pangenotypic activity and higher resistance barrier.

PSI-7851, a pronucleotide of beta-D-2'-deoxy-2'-fluoro-2'-C-methyluridine monophosphate, is a potent and pan-genotype inhibitor of hepatitis C virus replication.

PubMed

Lam, Angela M; Murakami, Eisuke; Espiritu, Christine; Steuer, Holly M Micolochick; Niu, Congrong; Keilman, Meg; Bao, Haiying; Zennou, Veronique; Bourne, Nigel; Julander, Justin G; Morrey, John D; Smee, Donald F; Frick, David N; Heck, Julie A; Wang, Peiyuan; Nagarathnam, Dhanapalan; Ross, Bruce S; Sofia, Michael J; Otto, Michael J; Furman, Phillip A

2010-08-01

The hepatitis C virus (HCV) NS5B RNA polymerase facilitates the RNA synthesis step during the HCV replication cycle. Nucleoside analogs targeting the NS5B provide an attractive approach to treating HCV infections because of their high barrier to resistance and pan-genotype activity. PSI-7851, a pronucleotide of beta-D-2'-deoxy-2'-fluoro-2'-C-methyluridine-5'-monophosphate, is a highly active nucleotide analog inhibitor of HCV for which a phase 1b multiple ascending dose study of genotype 1-infected individuals was recently completed (M. Rodriguez-Torres, E. Lawitz, S. Flach, J. M. Denning, E. Albanis, W. T. Symonds, and M. M. Berry, Abstr. 60th Annu. Meet. Am. Assoc. Study Liver Dis., abstr. LB17, 2009). The studies described here characterize the in vitro antiviral activity and cytotoxicity profile of PSI-7851. The 50% effective concentration for PSI-7851 against the genotype 1b replicon was determined to be 0.075+/-0.050 microM (mean+/-standard deviation). PSI-7851 was similarly effective against replicons derived from genotypes 1a, 1b, and 2a and the genotype 1a and 2a infectious virus systems. The active triphosphate, PSI-7409, inhibited recombinant NS5B polymerases from genotypes 1 to 4 with comparable 50% inhibitory concentrations. PSI-7851 is a specific HCV inhibitor, as it lacks antiviral activity against other closely related and unrelated viruses. PSI-7409 also lacked any significant activity against cellular DNA and RNA polymerases. No cytotoxicity, mitochondrial toxicity, or bone marrow toxicity was associated with PSI-7851 at the highest concentration tested (100 microM). Cross-resistance studies using replicon mutants conferring resistance to modified nucleoside analogs showed that PSI-7851 was less active against the S282T replicon mutant, whereas cells expressing a replicon containing the S96T/N142T mutation remained fully susceptible to PSI-7851. Clearance studies using replicon cells demonstrated that PSI-7851 was able to clear cells of HCV replicon RNA and prevent viral rebound.

Quantifying antiviral activity optimizes drug combinations against hepatitis C virus infection.

PubMed

Koizumi, Yoshiki; Ohashi, Hirofumi; Nakajima, Syo; Tanaka, Yasuhito; Wakita, Takaji; Perelson, Alan S; Iwami, Shingo; Watashi, Koichi

2017-02-21

With the introduction of direct-acting antivirals (DAAs), treatment against hepatitis C virus (HCV) has significantly improved. To manage and control this worldwide infectious disease better, the "best" multidrug treatment is demanded based on scientific evidence. However, there is no method available that systematically quantifies and compares the antiviral efficacy and drug-resistance profiles of drug combinations. Based on experimental anti-HCV profiles in a cell culture system, we quantified the instantaneous inhibitory potential (IIP), which is the logarithm of the reduction in viral replication events, for both single drugs and multiple-drug combinations. From the calculated IIP of 15 anti-HCV drugs from different classes [telaprevir, danoprevir, asunaprevir, simeprevir, sofosbuvir (SOF), VX-222, dasabuvir, nesbuvir, tegobuvir, daclatasvir, ledipasvir, IFN-α, IFN-λ1, cyclosporin A, and SCY-635], we found that the nucleoside polymerase inhibitor SOF had one of the largest potentials to inhibit viral replication events. We also compared intrinsic antiviral activities of a panel of drug combinations. Our quantification analysis clearly indicated an advantage of triple-DAA treatments over double-DAA treatments, with triple-DAA treatments showing enhanced antiviral activity and a significantly lower probability for drug resistance to emerge at clinically relevant drug concentrations. Our framework provides quantitative information to consider in designing multidrug strategies before costly clinical trials.

Kinetic pathway of 40S ribosomal subunit recruitment to hepatitis C virus internal ribosome entry site.

PubMed

Fuchs, Gabriele; Petrov, Alexey N; Marceau, Caleb D; Popov, Lauren M; Chen, Jin; O'Leary, Seán E; Wang, Richard; Carette, Jan E; Sarnow, Peter; Puglisi, Joseph D

2015-01-13

Translation initiation can occur by multiple pathways. To delineate these pathways by single-molecule methods, fluorescently labeled ribosomal subunits are required. Here, we labeled human 40S ribosomal subunits with a fluorescent SNAP-tag at ribosomal protein eS25 (RPS25). The resulting ribosomal subunits could be specifically labeled in living cells and in vitro. Using single-molecule Förster resonance energy transfer (FRET) between RPS25 and domain II of the hepatitis C virus (HCV) internal ribosome entry site (IRES), we measured the rates of 40S subunit arrival to the HCV IRES. Our data support a single-step model of HCV IRES recruitment to 40S subunits, irreversible on the initiation time scale. We furthermore demonstrated that after binding, the 40S:HCV IRES complex is conformationally dynamic, undergoing slow large-scale rearrangements. Addition of translation extracts suppresses these fluctuations, funneling the complex into a single conformation on the 80S assembly pathway. These findings show that 40S:HCV IRES complex formation is accompanied by dynamic conformational rearrangements that may be modulated by initiation factors.

Investigation of the role of GBF1 in the replication of positive-sense single-stranded RNA viruses.

PubMed

Ferlin, Juliette; Farhat, Rayan; Belouzard, Sandrine; Cocquerel, Laurence; Bertin, Antoine; Hober, Didier; Dubuisson, Jean; Rouillé, Yves

2018-06-20

GBF1 has emerged as a host factor required for the replication of positive-sense single-stranded RNA viruses of different families, but its mechanism of action is still unknown. GBF1 is a guanine nucleotide exchange factor for Arf family members. Recently, we identified Arf4 and Arf5 (class II Arfs) as host factors required for the replication of hepatitis C virus (HCV), a GBF1-dependent virus. To assess whether a GBF1/class II Arf pathway is conserved among positive-sense single-stranded RNA viruses, we investigated yellow fever virus (YFV), Sindbis virus (SINV), coxsackievirus B4 (CVB4) and human coronavirus 229E (HCoV-229E). We found that GBF1 is involved in the replication of these viruses. However, using siRNA or CRISPR-Cas9 technologies, it was seen that the depletion of Arf1, Arf3, Arf4 or Arf5 had no impact on viral replication. In contrast, the depletion of Arf pairs suggested that class II Arfs could be involved in HCoV-229E, YFV and SINV infection, as for HCV, but not in CVB4 infection. In addition, another Arf pair, Arf1 and Arf4, appears to be essential for YFV and SINV infection, but not for infection by other viruses. Finally, CVB4 infection was not inhibited by any combination of Arf depletion. We conclude that the mechanism of action of GBF1 in viral replication appears not to be conserved, and that a subset of positive-sense single-stranded RNA viruses from different families might require class II Arfs for their replication.

Liver stiffness is not associated with short- and long-term plasma HIV RNA replication in immunocompetent patients with HIV infection and with HIV/HCV coinfection

PubMed Central

Parisi, Saverio Giuseppe; Basso, Monica; Mengoli, Carlo; Scaggiante, Renzo; Andreis, Samantha; Franzetti, Marzia Maria; Cattelan, Anna Maria; Zago, Daniela; Cruciani, Mario; Andreoni, Massimo; Piovesan, Sara; Palù, Giorgio; Alberti, Alfredo

2017-01-01

Background Human immunodeficiency virus (HIV) may be directly responsible for liver damage but there are contrasting data regarding the influence of detectable plasma viremia. We analyzed the influence of plasma HIV RNA (pHIV) detectability and of other clinical and viro-immunological variables on liver stiffness (LS) measurement in adult immunocompetent HIV-monoinfected patients and in patients coinfected with hepatitis C virus (HCV). Methods Logistic regression analysis was performed using the value of LS>7.1 kPa as the dependent variable. A linear regression model was applied using LS measurement after log10 transformation (lkpa) as the dependent variable and we analyzed the predicted values versus the observed lkpa values; pHIV was classified as detectable or undetectable in the 12- and 36-month study periods before LS measurement. Results We studied 251 patients (178 with HIV monoinfection), most of whom were on antiviral treatment; 36-month study time was available for 154 subjects. The mean CD4+ cell count was 634 cells/mm3 in HIV-monoinfected patients and 606 cells/mm3 in coinfected patients. No difference in LS was found between patients with detectable or undetectable pHIV in either the 12- or the 36-month study period before transient elastography. The mean LS was higher in HIV/HCV coinfected patients (P<0.0001) than in the HIV-monoinfected subjects; lkpa was positively correlated with HCV coinfection (P<0.0001) and aspartate aminotransferase levels (P<0.0001). Detectable pHIV failed to reach significance. Eight HIV-monoinfected patients had a predicted LS measurement lower than the observed one, while eight patients had the opposite result. Conclusion LS was not correlated with ongoing HIV replication during the 12- and 36-month study periods in immunocompetent HIV-monoinfected and HIV/HCV-coinfected patients. PMID:28845109

HIV infection and hepatitis C virus genotype 1a are associated with phylogenetic clustering among people with recently acquired hepatitis C virus infection.

PubMed

Bartlett, Sofia R; Jacka, Brendan; Bull, Rowena A; Luciani, Fabio; Matthews, Gail V; Lamoury, Francois M J; Hellard, Margaret E; Hajarizadeh, Behzad; Teutsch, Suzy; White, Bethany; Maher, Lisa; Dore, Gregory J; Lloyd, Andrew R; Grebely, Jason; Applegate, Tanya L

2016-01-01

The aim of this study was to identify factors associated with phylogenetic clustering among people with recently acquired hepatitis C virus (HCV) infection. Participants with available sample at time of HCV detection were selected from three studies; the Australian Trial in Acute Hepatitis C, the Hepatitis C Incidence and Transmission Study - Prison and Community. HCV RNA was extracted and Core to E2 region of HCV sequenced. Clusters were identified from maximum likelihood trees with 1000 bootstrap replicates using 90% bootstrap and 5% genetic distance threshold. Among 225 participants with available Core-E2 sequence (ATAHC, n=113; HITS-p, n=90; and HITS-c, n=22), HCV genotype prevalence was: G1a: 38% (n=86), G1b: 5% (n=12), G2a: 1% (n=2), G2b: 5% (n=11), G3a: 48% (n=109), G6a: 1% (n=2) and G6l 1% (n=3). Of participants included in phylogenetic trees, 22% of participants were in a pair/cluster (G1a-35%, 30/85, mean maximum genetic distance=0.031; G3a-11%, 12/106, mean maximum genetic distance=0.021; other genotypes-21%, 6/28, mean maximum genetic distance=0.023). Among HCV/HIV co-infected participants, 50% (18/36) were in a pair/cluster, compared to 16% (30/183) with HCV mono-infection (P=<0.001). Factors independently associated with phylogenetic clustering were HIV co-infection [vs. HCV mono-infection; adjusted odds ratio (AOR) 4.24; 95%CI 1.91, 9.39], and HCV G1a infection (vs. other HCV genotypes; AOR 3.33, 95%CI 0.14, 0.61).HCV treatment and prevention strategies, including enhanced antiviral therapy, should be optimised. The impact of targeting of HCV treatment as prevention to populations with higher phylogenetic clustering, such as those with HIV co-infection, could be explored through mathematical modelling. Copyright © 2015 Elsevier B.V. All rights reserved.

Apolipoprotein E Likely Contributes to a Maturation Step of Infectious Hepatitis C Virus Particles and Interacts with Viral Envelope Glycoproteins

PubMed Central

Lee, Ji-Young; Acosta, Eliana G.; Stoeck, Ina Karen; Long, Gang; Hiet, Marie-Sophie; Mueller, Birthe; Fackler, Oliver T.; Kallis, Stephanie

2014-01-01

ABSTRACT The assembly of infectious hepatitis C virus (HCV) particles is tightly linked to components of the very-low-density lipoprotein (VLDL) pathway. We and others have shown that apolipoprotein E (ApoE) plays a major role in production of infectious HCV particles. However, the mechanism by which ApoE contributes to virion assembly/release and how it gets associated with the HCV particle is poorly understood. We found that knockdown of ApoE reduces titers of infectious intra- and extracellular HCV but not of the related dengue virus. ApoE depletion also reduced amounts of extracellular HCV core protein without affecting intracellular core amounts. Moreover, we found that ApoE depletion affected neither formation of nucleocapsids nor their envelopment, suggesting that ApoE acts at a late step of assembly, such as particle maturation and infectivity. Importantly, we demonstrate that ApoE interacts with the HCV envelope glycoproteins, most notably E2. This interaction did not require any other viral proteins and depended on the transmembrane domain of E2 that also was required for recruitment of HCV envelope glycoproteins to detergent-resistant membrane fractions. These results suggest that ApoE plays an important role in HCV particle maturation, presumably by direct interaction with viral envelope glycoproteins. IMPORTANCE The HCV replication cycle is tightly linked to host cell lipid pathways and components. This is best illustrated by the dependency of HCV assembly on lipid droplets and the VLDL component ApoE. Although the role of ApoE for production of infectious HCV particles is well established, it is still poorly understood how ApoE contributes to virion formation and how it gets associated with HCV particles. Here, we provide experimental evidence that ApoE likely is required for an intracellular maturation step of HCV particles. Moreover, we demonstrate that ApoE associates with the viral envelope glycoproteins. This interaction appears to be dispensable for envelopment of virus particles but likely contributes to the quality control of secreted infectious virions. These results shed new light on the exploitation of host cell lipid pathways by HCV and the link of viral particle assembly to the VLDL component ApoE. PMID:25122793

Useful biomarkers for assessment of hepatitis C virus infection-associated autoimmune disorders

PubMed Central

Yang, Deng-Ho; Ho, Ling-Jun; Lai, Jenn-Haung

2014-01-01

During the course of chronic hepatitis C virus (HCV) infection, various extrahepatic manifestations of autoimmune disorders may occur, including arthralgia/arthritis, sicca complex, purpura, cutaneous ulcer, and thyroid dysfunction. In addition, the prevalence of circulating autoantibodies is high among patients with HCV infection. Commonly detected autoantibodies in HCV-infected patients include rheumatoid factor, antinuclear antibody, anti-SSA/anti-SSB antibody, cryoglobulin, antineutrophil cytoplasmic antibody, anti-smooth muscle antibody, anti-liver and anti-thyroid autoantibodies. These autoantibodies may be associated with underlying autoimmune disorders or liver inflammation in HCV infection. A possible reason for antibody production is overactivation and proliferation of B lymphocytes, via the interaction with the surface protein of HCV. Because immunotherapy can cause HCV flare-up or liver damage, overdiagnosis of HCV-related autoimmune symptoms as primary autoimmune disorders should be avoided. This review describes biomarkers that are useful in clinically evaluating autoimmune manifestations and disorders associated with HCV infection. PMID:24659887

Management and treatment of hepatitis C virus in patients with HIV and hepatitis C virus coinfection: A practical guide for health care professionals.

PubMed

Côté, Pierre; Baril, Jean-Guy; Hébert, Marie-Nicole; Klein, Marina; Lalonde, Richard; Poliquin, Marc; Rouleau, Danielle; Therrien, Rachel; Vézina, Sylvie; Willems, Bernard; Dion, Harold; Junod, Patrice; Lapointe, Normand; Lévesque, Dominic; Pinault, Lyse; Tremblay, Cécile; Trottier, Benoît; Trottier, Sylvie; Tsoukas, Chris; Piché, Alain

2007-09-01

Concomitant HIV and hepatitis C virus (HCV) is a common yet complex coinfection. The present document is a practical guide for treating HCV infection in people coinfected with HIV. Effective antiretroviral therapies have prolonged survival rates for HIV-infected people over the past decade, which have made latent complications of HCV major causes of morbidity and mortality in these patients. Advances in the treatment of HCV (eg, combined pegylated interferon and ribavirin) offer the possibility of eradicating HCV infection in coinfected persons. The treatment of HCV must be considered in all cases. Intensive management of the adverse effects of HCV treatment is one of the factors for the success of these therapies. HCV eradication is predicted to decrease the mortality associated with coinfection and reduce the toxicity of HIV treatment.

Management and treatment of hepatitis C virus in patients with HIV and hepatitis C virus coinfection: A practical guide for health care professionals

PubMed Central

Côté, Pierre; Baril, Jean-Guy; Hébert, Marie-Nicole; Klein, Marina; Lalonde, Richard; Poliquin, Marc; Rouleau, Danielle; Therrien, Rachel; Vézina, Sylvie; Willems, Bernard; Dion, Harold; Junod, Patrice; Lapointe, Normand; Lévesque, Dominic; Pinault, Lyse; Tremblay, Cécile; Trottier, Benoît; Trottier, Sylvie; Tsoukas, Chris; Piché, Alain

2007-01-01

Concomitant HIV and hepatitis C virus (HCV) is a common yet complex coinfection. The present document is a practical guide for treating HCV infection in people coinfected with HIV. Effective antiretroviral therapies have prolonged survival rates for HIV-infected people over the past decade, which have made latent complications of HCV major causes of morbidity and mortality in these patients. Advances in the treatment of HCV (eg, combined pegylated interferon and ribavirin) offer the possibility of eradicating HCV infection in coinfected persons. The treatment of HCV must be considered in all cases. Intensive management of the adverse effects of HCV treatment is one of the factors for the success of these therapies. HCV eradication is predicted to decrease the mortality associated with coinfection and reduce the toxicity of HIV treatment. PMID:18923731

25-Hydroxy vitamin D suppresses hepatitis C virus replication and contributes to rapid virological response of treatment efficacy.

PubMed

Huang, Jee-Fu; Ko, Yu-Min; Huang, Chung-Feng; Yeh, Ming-Lun; Dai, Chia-Yen; Hsieh, Meng-Hsuan; Huang, Ching-I; Yang, Hua-Ling; Wang, Shu-Chi; Lin, Zu-Yau; Chen, Shinn-Chern; Yu, Ming-Lung; Chuang, Wan-Long

2017-12-01

25-Hydroxy vitamin D (Vit D) plays a role in treatment outcomes in chronic hepatitis C virus (HCV) infection. We aimed to clarify whether HCV replication is inhibited by Vit D in HCV replicon cells. Clinical implication was assessed for rapid virological response (RVR) and sustained virological response (SVR) among those patients receiving antiviral therapy. Cell survival and viral loads were observed in Con1 (genotype 1b) and J6/JFH (genotype 2a) cells treated with different doses of Vit D. Three groups of patients with different treatment responses were recruited to assess their Vit D levels: group A, RVR-/SVR-; group B, RVR+/SVR-; and group C, RVR+/SVR+. The viral load of Con1 cells decreased by 69%, 80%, and 86% following treatment with 1 μM, 5 μM, and 10 μM Vit D, respectively (P < 0.0001). In J6/JFH cells, it decreased by 12%, 55%, and 80.5% following treatment with 1 μM, 5 μM, and 10 μM Vit D, respectively (P < 0.0001). There was a significant increase of Vit D between chronic hepatitis C groups, ranging from 4.4 ± 5.6 ng/mL in group A (n = 44), to 17.2 ± 11.6 ng/mL in group B (n = 44), and 32.5 ± 37.5 ng/mL of group C (n = 44) (P < 0.001). Advanced fibrosis (odds ratio = 0.13, 95% confidence interval = 0.04-0.41, P < 0.001) and Vit D deficiency (<10 ng/mL) (odds ratio = 0.11, 95% confidence interval = 0.03-0.43, P = 0.001) were predictive of SVR in the multivariate regression analysis. Vitamin D decreases HCV replication and also contributes to early treatment viral kinetics. © 2017 The Japan Society of Hepatology.

The Elav-like protein HuR exerts translational control of viral internal ribosome entry sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivas-Aravena, Andrea; Ramdohr, Pablo; Vallejos, Maricarmen

2009-09-30

The human embryonic-lethal abnormal vision (ELAV)-like protein, HuR, has been recently found to be involved in the regulation of protein synthesis. In this study we show that HuR participates in the translational control of the HIV-1 and HCV IRES elements. HuR functions as a repressor of HIV-1 IRES activity and acts as an activator of the HCV IRES. The effect of HuR was evaluated in three independent experimental systems, rabbit reticulocyte lysate, HeLa cells, and Xenopus laevis oocytes, using both overexpression and knockdown approaches. Furthermore, results suggest that HuR mediated regulation of HIV-1 and HCV IRESes does not require directmore » binding of the protein to the RNA nor does it need the nuclear translocation of the IRES-containing RNAs. Finally, we show that HuR has a negative impact on post-integration steps of the HIV-1 replication cycle. Thus, our observations yield novel insights into the role of HuR in the post-transcriptional regulation of HCV and HIV-1 gene expression.« less

Virtual Screening and Molecular Dynamics Simulations from a Bank of Molecules of the Amazon Region Against Functional NS3-4A Protease-Helicase Enzyme of Hepatitis C Virus.

PubMed

Pinheiro, Alan Sena; Duarte, Jaqueline Bianca Carvalho; Alves, Cláudio Nahum; de Molfetta, Fábio Alberto

2015-07-01

Hepatitis C virus (HCV) infection is a disease that affects approximately 3% of the global population and requires new therapeutic agents without the inconvenience associated with current anti-HCV treatment. This paper reports on a study of a virtual screening and a molecular dynamics simulation of compounds derived from natural products from the Amazon region that are potentially effective against the NS3-4A enzyme of HCV, which plays an important role in the replication process of this virus. According to the results of the molecular docking calculations and subsequent consensual analysis, the best scored compounds showed interactions between hydrogen and residues of the catalytic triad as well as interactions with residues that guide ligands to the active site of the enzyme. They also showed stability in the molecular dynamics simulation, as the structures preserved important interactions at the active site of the enzyme. The root mean square deviation (RMSD) values were stabilized at the end of the simulation time. Such compounds are considered promising as novel therapies against HCV.

The impact of hepatitis C on labor force participation, absenteeism, presenteeism and non-work activities.

PubMed

DiBonaventura, Marco daCosta; Wagner, Jan-Samuel; Yuan, Yong; L'Italien, Gilbert; Langley, Paul; Ray Kim, W

2011-01-01

Between 2.7 and 3.9 million people are currently infected with the hepatitis C virus (HCV) in the United States. Although many studies have investigated the impact of HCV on direct healthcare costs, few studies have estimated the indirect costs associated with the virus using a nationally-representative dataset. Using data from the 2009 United States (US) National Health and Wellness Survey, patients who reported a hepatitis C diagnosis (n = 695) were compared to controls on labor force participation, productivity loss, and activity impairment after adjusting for demographics, health risk behaviors, and comorbidities. All analyses applied sampling weights to project to the population. Patients with HCV were significantly less likely to be in the labor force than controls and reported significantly higher levels of absenteeism (4.88 vs. 3.03%), presenteeism (16.69 vs. 13.50%), overall work impairment (19.40 vs.15.35%), and activity impairment (25.01 vs. 21.78%). A propensity score matching methodology replicated many of these findings. While much of the work on HCV has focused on direct costs, our results suggest indirect costs should not be ignored when quantifying the societal burden of HCV. To our knowledge, this is the first study which has utilized a large, nationally-representative data source for identifying the impact of HCV on labor force participation and work and activity impairment using both a propensity-score matching and a regression modeling framework. All data were patient-reported (including HCV diagnosis and work productivity), which could have introduced some subjective biases.

Outcomes of Hepatitis C Treatment by Primary Care Providers

PubMed Central

Arora, Sanjeev; Thornton, Karla; Murata, Glen; Deming, Paulina; Kalishman, Summers; Dion, Denise; Parish, Brooke; Burke, Thomas; Pak, Wesley; Dunkelberg, Jeffrey; Kistin, Martin; Brown, John; Jenkusky, Steven; Komaromy, Miriam; Qualls, Clifford

2013-01-01

Background The Extension for Community Healthcare Outcomes (ECHO) model was developed to improve access to care for complex health problems such as hepatitis C virus (HCV) infection for underserved populations. Using videoconferencing technology, ECHO trains primary care providers to treat complex diseases. Methods A prospective cohort study compared treatment of HCV at the University of New Mexico (UNM) HCV clinic to treatment by primary care clinicians at 21 ECHO sites in rural areas and prisons in New Mexico. A total of 407 treatment naive patients with chronic HCV were enrolled. The primary end point was a sustained viral response (SVR). Results The rate of SVR was 57.5% (84/146) for patients treated at UNM and 58.2% (152 /261) at ECHO sites (P=0.89); difference between SVR rates 0.7% (95% CI -9.2%, 10.7%). In genotype 1 infection the SVR rate was 45.8% (38 /83) at UNM and 49.7% (73 /147) at ECHO sites (P=0.57). Serious adverse events occurred in 13.7% of the UNM HCV clinic cohort and 6.9% of the ECHO cohort. Conclusions This study demonstrates that the ECHO model is an effective way to treat HCV in underserved communities. Implementation of this model would allow other states and nations to treat more patients with HCV. PMID:21631316

Identification of novel RNA secondary structures within the hepatitis C virus genome reveals a cooperative involvement in genome packaging

PubMed Central

Stewart, H.; Bingham, R.J.; White, S. J.; Dykeman, E. C.; Zothner, C.; Tuplin, A. K.; Stockley, P. G.; Twarock, R.; Harris, M.

2016-01-01

The specific packaging of the hepatitis C virus (HCV) genome is hypothesised to be driven by Core-RNA interactions. To identify the regions of the viral genome involved in this process, we used SELEX (systematic evolution of ligands by exponential enrichment) to identify RNA aptamers which bind specifically to Core in vitro. Comparison of these aptamers to multiple HCV genomes revealed the presence of a conserved terminal loop motif within short RNA stem-loop structures. We postulated that interactions of these motifs, as well as sub-motifs which were present in HCV genomes at statistically significant levels, with the Core protein may drive virion assembly. We mutated 8 of these predicted motifs within the HCV infectious molecular clone JFH-1, thereby producing a range of mutant viruses predicted to possess altered RNA secondary structures. RNA replication and viral titre were unaltered in viruses possessing only one mutated structure. However, infectivity titres were decreased in viruses possessing a higher number of mutated regions. This work thus identified multiple novel RNA motifs which appear to contribute to genome packaging. We suggest that these structures act as cooperative packaging signals to drive specific RNA encapsidation during HCV assembly. PMID:26972799

Depsides: Lichen Metabolites Active against Hepatitis C Virus

PubMed Central

Vu, Thi Huyen; Le Lamer, Anne-Cécile; Lalli, Claudia; Boustie, Joël; Samson, Michel

2015-01-01

A thorough phytochemical study of Stereocaulon evolutum was conducted, for the isolation of structurally related atranorin derivatives. Indeed, pilot experiments suggested that atranorin (1), the main metabolite of this lichen, would interfere with the lifecycle of hepatitis C virus (HCV). Eight compounds, including one reported for the first time (2), were isolated and characterized. Two analogs (5, 6) were also synthesized, to enlarge the panel of atranorin-related structures. Most of these compounds were active against HCV, with a half-maximal inhibitory concentration of about 10 to 70 µM, with depsides more potent than monoaromatic phenols. The most effective inhibitors (1, 5 and 6) were then added at different steps of the HCV lifecycle. Interestingly, atranorin (1), bearing an aldehyde function at C-3, inhibited only viral entry, whereas the synthetic compounds 5 and 6, bearing a hydroxymethyl and a methyl function, respectively, at C-3 interfered with viral replication. PMID:25793970

Hepatitis C Virus and Antiviral Drug Resistance.

PubMed

Kim, Seungtaek; Han, Kwang-Hyub; Ahn, Sang Hoon

2016-11-15

Since its discovery in 1989, hepatitis C virus (HCV) has been intensively investigated to understand its biology and develop effective antiviral therapies. The efforts of the previous 25 years have resulted in a better understanding of the virus, and this was facilitated by the development of in vitro cell culture systems for HCV replication. Antiviral treatments and sustained virological responses have also improved from the early interferon monotherapy to the current all-oral regimens using direct-acting antivirals. However, antiviral resistance has become a critical issue in the treatment of chronic hepatitis C, similar to other chronic viral infections, and retreatment options following treatment failure have become important questions. Despite the clinical challenges in the management of chronic hepatitis C, substantial progress has been made in understanding HCV, which may facilitate the investigation of other closely related flaviviruses and lead to the development of antiviral agents against these human pathogens.

A galactose-functionalized dendritic siRNA-nanovector to potentiate hepatitis C inhibition in liver cells

NASA Astrophysics Data System (ADS)

Lakshminarayanan, Abirami; Reddy, B. Uma; Raghav, Nallani; Ravi, Vijay Kumar; Kumar, Anuj; Maiti, Prabal K.; Sood, A. K.; Jayaraman, N.; Das, Saumitra

2015-10-01

A RNAi based antiviral strategy holds the promise to impede hepatitis C viral (HCV) infection overcoming the problem of emergence of drug resistant variants, usually encountered in the interferon free direct-acting antiviral therapy. Targeted delivery of siRNA helps minimize adverse `off-target' effects and maximize the efficacy of therapeutic response. Herein, we report the delivery of siRNA against the conserved 5'-untranslated region (UTR) of HCV RNA using a liver-targeted dendritic nano-vector functionalized with a galactopyranoside ligand (DG). Physico-chemical characterization revealed finer details of complexation of DG with siRNA, whereas molecular dynamic simulations demonstrated sugar moieties projecting ``out'' in the complex. Preferential delivery of siRNA to the liver was achieved through a highly specific ligand-receptor interaction between dendritic galactose and the asialoglycoprotein receptor. The siRNA-DG complex exhibited perinuclear localization in liver cells and co-localization with viral proteins. The histopathological studies showed the systemic tolerance and biocompatibility of DG. Further, whole body imaging and immunohistochemistry studies confirmed the preferential delivery of the nucleic acid to mice liver. Significant decrease in HCV RNA levels (up to 75%) was achieved in HCV subgenomic replicon and full length HCV-JFH1 infectious cell culture systems. The multidisciplinary approach provides the `proof of concept' for restricted delivery of therapeutic siRNAs using a target oriented dendritic nano-vector.A RNAi based antiviral strategy holds the promise to impede hepatitis C viral (HCV) infection overcoming the problem of emergence of drug resistant variants, usually encountered in the interferon free direct-acting antiviral therapy. Targeted delivery of siRNA helps minimize adverse `off-target' effects and maximize the efficacy of therapeutic response. Herein, we report the delivery of siRNA against the conserved 5'-untranslated region (UTR) of HCV RNA using a liver-targeted dendritic nano-vector functionalized with a galactopyranoside ligand (DG). Physico-chemical characterization revealed finer details of complexation of DG with siRNA, whereas molecular dynamic simulations demonstrated sugar moieties projecting ``out'' in the complex. Preferential delivery of siRNA to the liver was achieved through a highly specific ligand-receptor interaction between dendritic galactose and the asialoglycoprotein receptor. The siRNA-DG complex exhibited perinuclear localization in liver cells and co-localization with viral proteins. The histopathological studies showed the systemic tolerance and biocompatibility of DG. Further, whole body imaging and immunohistochemistry studies confirmed the preferential delivery of the nucleic acid to mice liver. Significant decrease in HCV RNA levels (up to 75%) was achieved in HCV subgenomic replicon and full length HCV-JFH1 infectious cell culture systems. The multidisciplinary approach provides the `proof of concept' for restricted delivery of therapeutic siRNAs using a target oriented dendritic nano-vector. Electronic supplementary information (ESI) available: Spectral data and experimental details. See DOI: 10.1039/c5nr02898a

In Vitro Antiviral Activity and Resistance Profile of the Next-Generation Hepatitis C Virus NS5A Inhibitor Pibrentasvir.

PubMed

Ng, Teresa I; Krishnan, Preethi; Pilot-Matias, Tami; Kati, Warren; Schnell, Gretja; Beyer, Jill; Reisch, Thomas; Lu, Liangjun; Dekhtyar, Tatyana; Irvin, Michelle; Tripathi, Rakesh; Maring, Clarence; Randolph, John T; Wagner, Rolf; Collins, Christine

2017-05-01

Pibrentasvir (ABT-530) is a novel and pan-genotypic hepatitis C virus (HCV) NS5A inhibitor with 50% effective concentration (EC 50 ) values ranging from 1.4 to 5.0 pM against HCV replicons containing NS5A from genotypes 1 to 6. Pibrentasvir demonstrated similar activity against a panel of chimeric replicons containing HCV NS5A of genotypes 1 to 6 from clinical samples. Resistance selection studies were conducted using HCV replicon cells with NS5A from genotype 1a, 1b, 2a, 2b, 3a, 4a, 5a, or 6a at a concentration of pibrentasvir that was 10- or 100-fold over its EC 50 for the respective replicon. With pibrentasvir at 10-fold over the respective EC 50 , only a small number of colonies (0.00015 to 0.0065% of input cells) with resistance-associated amino acid substitutions were selected in replicons containing genotype 1a, 2a, or 3a NS5A, and no viable colonies were selected in replicons containing NS5A from other genotypes. With pibrentasvir at 100-fold over the respective EC 50 , very few colonies (0.0002% of input cells) were selected by pibrentasvir in genotype 1a replicon cells while no colonies were selected in other replicons. Pibrentasvir is active against common resistance-conferring substitutions in HCV genotypes 1 to 6 that were identified for other NS5A inhibitors, including those at key amino acid positions 28, 30, 31, or 93. The combination of pibrentasvir with HCV inhibitors of other classes produced synergistic inhibition of HCV replication. In summary, pibrentasvir is a next-generation HCV NS5A inhibitor with potent and pan-genotypic activity, and it maintains activity against common amino acid substitutions of HCV genotypes 1 to 6 that are known to confer resistance to currently approved NS5A inhibitors. Copyright © 2017 Ng et al.

A New Signaling Pathway for HCV Inhibition by Estrogen: GPR30 Activation Leads to Cleavage of Occludin by MMP-9.

PubMed

Ulitzky, Laura; Lafer, Manuel M; KuKuruga, Mark A; Silberstein, Erica; Cehan, Nicoleta; Taylor, Deborah R

2016-01-01

Poor outcome in response to hepatitis C virus, including higher viral load, hepatocellular carcinoma and cirrhosis, is more associated with men and postmenopausal women than with premenopausal women and women receiving hormone replacement therapy, suggesting that β-estradiol plays an innate role in preventing viral infection and liver disease. Consequently, most research in the field has concluded that estrogen affects HCV replication through viral interactions with estrogen receptor-α. Previously, estrogen-like antagonists, including Tamoxifen, were shown to reduce HCV RNA production and prevent viral entry, although the authors did not identify host factors involved. Estrogen can act alternatively through the membrane-bound G-protein-coupled estrogen receptor, GPR30. Here, human hepatoma Huh7.5 cells were infected with HCV J6/JFH-1 and treated with estrogen or Tamoxifen, resulting in a marked decrease in detectable virus. The effect was mimicked by G1, a GPR30-specific agonist, and was reversed by the GPR30-specific antagonist, G15. While previous studies have demonstrated that estrogen down-regulated occludin in cervical cancer cells, its action on liver cells was unknown. Occludin is a tight junction protein and HCV receptor and here we report that activation and cellular export of MMP-9 led to the cleavage of occludin upon estrogen treatment of liver cells. This is the first report of the cleavage of an HCV receptor in response to estrogen. We also identify the occludin cleavage site in extracellular Domain D; the motif required for HCV entry and spread. This pathway gives new insight into a novel innate antiviral pathway and the suboptimal environment that estrogen provides for the proliferation of the virus. It may also explain the disparate host-virus responses to HCV demonstrated by the two sexes. Moreover, these data suggest that hormone replacement therapy may have beneficial antiviral enhancement properties for HCV-infected postmenopausal women and show promise for new antiviral treatments for both men and women.

A Point Mutation in the N-Terminal Amphipathic Helix α0 in NS3 Promotes Hepatitis C Virus Assembly by Altering Core Localization to the Endoplasmic Reticulum and Facilitating Virus Budding.

PubMed

Yan, Yu; He, Ying; Boson, Bertrand; Wang, Xuesong; Cosset, François-Loïc; Zhong, Jin

2017-03-15

The assembly of hepatitis C virus (HCV), a complicated process in which many viral and cellular factors are involved, has not been thoroughly deciphered. NS3 is a multifunctional protein that contains an N-terminal amphipathic α helix (designated helix α 0 ), which is crucial for the membrane association and stability of NS3 protein, followed by a serine protease domain and a C-terminal helicase/NTPase domain. NS3 participates in HCV assembly likely through its C-terminal helicase domain, in which all reported adaptive mutations enhancing virion assembly reside. In this study, we determined that the N-terminal helix α 0 of NS3 may contribute to HCV assembly. We identified a single mutation from methionine to threonine at amino acid position 21 (M21T) in helix α 0 , which significantly promoted viral production while having no apparent effect on the membrane association and protease activity of NS3. Subsequent analyses demonstrated that the M21T mutation did not affect HCV genome replication but rather promoted virion assembly. Further study revealed a shift in the subcellular localization of core protein from lipid droplets (LD) to the endoplasmic reticulum (ER). Finally, we showed that the M21T mutation increased the colocalization of core proteins and viral envelope proteins, leading to a more efficient envelopment of viral nucleocapsids. Collectively, the results of our study revealed a new function of NS3 helix α 0 and aid understanding of the role of NS3 in HCV virion morphogenesis. IMPORTANCE HCV NS3 protein possesses the protease activity in its N-terminal domain and the helicase activity in its C-terminal domain. The role of NS3 in virus assembly has been mainly attributed to its helicase domain, because all adaptive mutations enhancing progeny virus production are found to be within this domain. Our study identified, for the first time to our knowledge, an adaptive mutation within the N-terminal helix α 0 domain of NS3 that significantly enhanced virus assembly while having no effect on viral genome replication. The mechanistic studies suggested that this mutation promoted the relocation of core proteins from LD to the ER, leading to a more efficient envelopment of viral nucleocapsids. Our results revealed a possible new function of helix α 0 in the HCV life cycle and provided new clues to understanding the molecular mechanisms for the action of NS3 in HCV assembly. Copyright © 2017 American Society for Microbiology.

The Purification and Concentration of Hog Cholera Virus*

PubMed Central

Cunliffe, H. R.; Rebers, P. A.

1968-01-01

Partial purification of hog cholera virus (HCV) using a simple batch-type chromatographic procedure with magnetic ferric oxide (MFO) is described. Infectious HCV was adsorbed from isotonic solutions to MFO and was eluted under conditions of low ionic strength and high pH. Aqueous solutions of 0.01 M sodium cyanide or 0.0003 M ammonium hydroxide effectively dissociated MFO-HCV complexes. The data indicate that 50 to 100% of the original HCV infectivity was recovered concomitant with a 90 to 95% reduction of extraneous organic nitrogen. MFO-purified HCV was concentrated by density gradient type centrifugations in buffered solutions of cesium chloride and sucrose. Prolonged isodensity centrifugations of concentrated MFO-purified HCV indicated a buoyant density of 1.14 to 1.15 gm/ml for the strain of virus used. PMID:15846899

Clinical impact of non-organ-specific autoantibodies on the response to combined antiviral treatment in patients with hepatitis C.

PubMed

Muratori, Paolo; Muratori, Luigi; Guidi, Marcello; Granito, Alessandro; Susca, Micaela; Lenzi, Marco; Bianchi, Francesco B

2005-02-15

Hepatitis C virus (HCV)-related chronic hepatitis is frequently associated with non-organ-specific autoantibodies (NOSAs), but available data about the relationship between NOSA positivity and the effect of antiviral therapy in persons with hepatitis C are few and controversial. Our aim was to evaluate the impact of NOSA positivity on the outcome of combined antiviral therapy in HCV-positive patients. A total of 143 consecutive adult patients with hepatitis C were studied. Antinuclear antibody (ANA), anti-smooth muscle antibody (SMA), and anti-liver/kidney microsomal antibody type 1 (LKM1) were detected by indirect immunofluorescence. All patients were treatment naive and received combined antiviral therapy (interferon [IFN]-ribavirin) after enrollment in the study. Patients were classified as nonresponders if HCV RNA was detectable after 6 months of therapy, as relapsers if abnormal transaminase levels and reactivation of HCV replication were observed after the end of treatment, and as long-term responders if transaminase levels were persistently normal and HCV RNA was undetectable 6 months after the end of treatment. Thirty-seven patients (25%) were NOSA positive (SMA was detected in 19 patients, ANA in 10, ANA and SMA in 4, LKM1 in 3, and SMA and LKM1 in 1). The prevalence of long-term response was similar between NOSA-positive patients and NOSA-negative patients (48.6% vs. 56.6%; P=not significant). Compared with HCV genotype 1 (HCV-1), HCV genotypes other than 1 were more often associated with long-term response among NOSA-positive patients (93.3% vs. 30%; P=.0017). The overall rate of long-term response, irrespective of NOSA status, was 54.5%. Detection of HCV-1 and elevated gamma-glutamyl transpeptidase serum levels were independent negative prognostic factors of treatment response (P=.007 and P=.026, respectively). Combined antiviral treatment (IFN-ribavirin) is safe and effective in NOSA-positive patients with hepatitis C, even if long-term response is less likely in those infected with HCV-1.

Prediction of minimal residual viremia in HCV type 1 infected patients receiving interferon-based therapy.

PubMed

Knop, Viola; Teuber, Gerlinde; Klinker, Hartwig; Möller, Bernd; Rasenack, Jens; Hinrichsen, Holger; Gerlach, Tilman; Spengler, Ulrich; Buggisch, Peter; Neumann, Konrad; Sarrazin, Christoph; Zeuzem, Stefan; Berg, Thomas

2013-01-01

Complete suppression of viral replication is crucial in chronic HCV treatment in order to prevent relapse and resistance development. We wanted to find out which factors influence the period from being already HCV RNA negative by bDNA assay (< 615 IU/mL) to become undetectable by the more sensitive TMA test (< 5.3 IU/mL). Evaluated were 433 HCV type 1-infected patients. All of them received 1.5 ug/kg Peg-IFNα-2b plus ribavirin for 18-48 weeks. bDNA was performed weekly during the first 8 weeks and thereafter at weeks 12, 24, and 48. Patients who became bDNA undetectable were additionally analysed by TMA. Of the 309 patients with on-treatment response (< 615 IU/mL), 289 also reached undetectable HCV RNA levels by TMA. Multivariate analysis revealed that viremia ≤ 400,000 IU/mL (p = 0.001), fast initial virologic decline (p = 0.004) and absence of fibrosis (p = 0.035) were independent predictors of an accelerated on-treatment response by TMA assay in already bDNA negative patients. bDNA negative patients becoming HCV RNA undetectable by TMA within the following 3 weeks had a frequency of relapse of 21%, whereas those showing TMA negativity after 3 weeks relapsed in 38% (p = 0.001). In RVR patients (bDNA < 615 IU/mL at week 4) the corresponding relapse rates were 15.3% vs. 37.5%, respectively (p = 0.003). Early viral kinetics, baseline viremia and fibrosis stage are important tools to predict persistent minimal viremia during interferon-based therapy. The data have implications for designing a more refined treatment strategy in HCV infection, even in the setting of protease inhibitor-based triple treatment.

Replication and Oncolytic Activity of an Avian Orthoreovirus in Human Hepatocellular Carcinoma Cells

PubMed Central

Kozak, Robert A.; Hattin, Larissa; Biondi, Mia J.; Corredor, Juan C.; Walsh, Scott; Xue-Zhong, Max; Manuel, Justin; McGilvray, Ian D.; Morgenstern, Jason; Lusty, Evan; Cherepanov, Vera; McBey, Betty-Anne; Leishman, David; Feld, Jordan J.; Bridle, Byram; Nagy, Éva

2017-01-01

Oncolytic viruses are cancer therapeutics with promising outcomes in pre-clinical and clinical settings. Animal viruses have the possibility to avoid pre-existing immunity in humans, while being safe and immunostimulatory. We isolated an avian orthoreovirus (ARV-PB1), and tested it against a panel of hepatocellular carcinoma cells. We found that ARV-PB1 replicated well and induced strong cytopathic effects. It was determined that one mechanism of cell death was through syncytia formation, resulting in apoptosis and induction of interferon stimulated genes (ISGs). As hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma worldwide, we investigated the effect of ARV-PB1 against cells already infected with this virus. Both HCV replicon-containing and infected cells supported ARV-PB1 replication and underwent cytolysis. Finally, we generated in silico models to compare the structures of human reovirus- and ARV-PB1-derived S1 proteins, which are the primary targets of neutralizing antibodies. Tertiary alignments confirmed that ARV-PB1 differs from its human homolog, suggesting that immunity to human reoviruses would not be a barrier to its use. Therefore, ARV-PB1 can potentially expand the repertoire of oncolytic viruses for treatment of human hepatocellular carcinoma and other malignancies. PMID:28441762

Hepatitis E virus persists in the presence of a type III interferon response.

PubMed

Yin, Xin; Li, Xinlei; Ambardekar, Charuta; Hu, Zhimin; Lhomme, Sébastien; Feng, Zongdi

2017-05-01

The RIG-I-like RNA helicase (RLR)-mediated interferon (IFN) response plays a pivotal role in the hepatic antiviral immunity. The hepatitis A virus (HAV) and the hepatitis C virus (HCV) counter this response by encoding a viral protease that cleaves the mitochondria antiviral signaling protein (MAVS), a common signaling adaptor for RLRs. However, a third hepatotropic RNA virus, the hepatitis E virus (HEV), does not appear to encode a functional protease yet persists in infected cells. We investigated HEV-induced IFN responses in human hepatoma cells and primary human hepatocytes. HEV infection resulted in persistent virus replication despite poor spread. This was companied by a type III IFN response that upregulated multiple IFN-stimulated genes (ISGs), but type I IFNs were barely detected. Blocking type III IFN production or signaling resulted in reduced ISG expression and enhanced HEV replication. Unlike HAV and HCV, HEV did not cleave MAVS; MAVS protein size, mitochondrial localization, and function remained unaltered in HEV-replicating cells. Depletion of MAVS or MDA5, and to a less extent RIG-I, also diminished IFN production and increased HEV replication. Furthermore, persistent activation of the JAK/STAT signaling rendered infected cells refractory to exogenous IFN treatment, and depletion of MAVS or the receptor for type III IFNs restored the IFN responsiveness. Collectively, these results indicate that unlike other hepatotropic RNA viruses, HEV does not target MAVS and its persistence is associated with continuous production of type III IFNs.

Applications of computer-aided approaches in the development of hepatitis C antiviral agents.

PubMed

Ganesan, Aravindhan; Barakat, Khaled

2017-04-01

Hepatitis C virus (HCV) is a global health problem that causes several chronic life-threatening liver diseases. The numbers of people affected by HCV are rising annually. Since 2011, the FDA has approved several anti-HCV drugs; while many other promising HCV drugs are currently in late clinical trials. Areas covered: This review discusses the applications of different computational approaches in HCV drug design. Expert opinion: Molecular docking and virtual screening approaches have emerged as a low-cost tool to screen large databases and identify potential small-molecule hits against HCV targets. Ligand-based approaches are useful for filtering-out compounds with rich physicochemical properties to inhibit HCV targets. Molecular dynamics (MD) remains a useful tool in optimizing the ligand-protein complexes and understand the ligand binding modes and drug resistance mechanisms in HCV. Despite their varied roles, the application of in-silico approaches in HCV drug design is still in its infancy. A more mature application should aim at modelling the whole HCV replicon in its active form and help to identify new effective druggable sites within the replicon system. With more technological advancements, the roles of computer-aided methods are only going to increase several folds in the development of next-generation HCV drugs.

Hepatitis C serosorting among people who inject drugs in rural Puerto Rico.

PubMed

Duncan, Ian; Curtis, Ric; Reyes, Juan Carlos; Abadie, Roberto; Khan, Bilal; Dombrowski, Kirk

2017-06-01

Due to the high cost of treatment, preventative measures to limit Hepatitis C (HCV) transmission among people who inject drugs (PWID) are encouraged by many public health officials. A key one of these is serosorting, where PWID select risk partners based on concordant HCV status. Research on the general U.S. population by Smith et al. (2013) found that knowledge of one's own HCV status facilitated serosorting behaviors among PWID, such that respondents with knowledge of their own status were more likely to ask potential partners about their status prior to sharing risk. Our objective was to see if this held true in rural Puerto Rico. We replicate this study using a sample of PWID in rural Puerto Rico to draw comparisons. We used respondent driven sampling to survey 315 participants, and have a final analytic sample of 154. The survey was heavily modeled after the National HIV Behavioral Survey, which was the dataset used by the previous researchers. We found that among PWID in rural Puerto Rico, unlike in the general population, knowledge of one's own HCV status had no significant effect on the selection of one's most recent injection partner, based on his/her HCV status. We conclude that PWID in rural Puerto Rico differ from the general U.S. population when it comes to serosorting behaviors, and that these differences should be taken into account in future outreaches and intervention strategies.

N6-Methyladenosine in Flaviviridae Viral RNA Genomes Regulates Infection.

PubMed

Gokhale, Nandan S; McIntyre, Alexa B R; McFadden, Michael J; Roder, Allison E; Kennedy, Edward M; Gandara, Jorge A; Hopcraft, Sharon E; Quicke, Kendra M; Vazquez, Christine; Willer, Jason; Ilkayeva, Olga R; Law, Brittany A; Holley, Christopher L; Garcia-Blanco, Mariano A; Evans, Matthew J; Suthar, Mehul S; Bradrick, Shelton S; Mason, Christopher E; Horner, Stacy M

2016-11-09

The RNA modification N6-methyladenosine (m 6 A) post-transcriptionally regulates RNA function. The cellular machinery that controls m 6 A includes methyltransferases and demethylases that add or remove this modification, as well as m 6 A-binding YTHDF proteins that promote the translation or degradation of m 6 A-modified mRNA. We demonstrate that m 6 A modulates infection by hepatitis C virus (HCV). Depletion of m 6 A methyltransferases or an m 6 A demethylase, respectively, increases or decreases infectious HCV particle production. During HCV infection, YTHDF proteins relocalize to lipid droplets, sites of viral assembly, and their depletion increases infectious viral particles. We further mapped m 6 A sites across the HCV genome and determined that inactivating m 6 A in one viral genomic region increases viral titer without affecting RNA replication. Additional mapping of m 6 A on the RNA genomes of other Flaviviridae, including dengue, Zika, yellow fever, and West Nile virus, identifies conserved regions modified by m 6 A. Altogether, this work identifies m 6 A as a conserved regulatory mark across Flaviviridae genomes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Changes in serum hepatitis C virus RNA in interferon nonresponders retreated with interferon plus ribavirin: a preliminary report.

PubMed

Nyberg, L; Albrecht, J; Glue, P; Gianelli, G; Zambas, D; Elliot, M; Conrad, A; McHutchison, J

1999-06-01

Ribavirin, a nucleoside analogue, inhibits replication of RNA and DNA viruses and may control hepatitis C virus (HCV) infection through modulation of anti-inflammatory and antiviral actions. Ribavirin monotherapy has no effect on serum HCV RNA levels. In combination with interferon, this agent appears to enhance the efficacy of interferon. The aim of this study was to monitor serum HCV RNA levels early during therapy with interferon and ribavirin compared with that previously seen in the same patients during interferon monotherapy. Five patients who previously showed no response to therapy with interferon alfa 3 MU three times weekly for 6 months were retreated with the identical dose of interferon alfa 2b in combination with oral ribavirin 1,000 mg/day. Serum HCV RNA levels were monitored at baseline, week 4, week 8, and week 12 of therapy by a quantitative multicycle polymerase chain reaction assay. In the first 8 to 12 weeks, serum HCV RNA levels showed a greater decrease in all patients when retreated with combination therapy compared with interferon alone. Mean (+/- SEM) serum HCV RNA levels for interferon therapy alone were 3.3 +/- 0.95, 1.2 +/- 0.95, 1.6 +/- 1.2, and 2.3 +/- 1.2 x 10(6) copies/ml at week 0, 4, 8, and 12, respectively. This was compared with 3.3 +/- 0.83, 0.3 +/- 0.2, 0.03 +/- 0.02, and 0.15 +/- 0.14 x 10(6), respectively, for the interferon and ribavirin group (p < 0.07 at week 8). Two of five patients had undetectable serum HCV RNA during combination therapy. Combination therapy with interferon and ribavirin in prior interferon nonresponders reduces serum HCV RNA levels compared with interferon alone. This may suggest some additional antiviral effect of ribavirin when given with interferon.

Vertically acquired hepatitis C virus infection: Correlates of transmission and disease progression.

PubMed

Tovo, Pier-Angelo; Calitri, Carmelina; Scolfaro, Carlo; Gabiano, Clara; Garazzino, Silvia

2016-01-28

The worldwide prevalence of hepatitis C virus (HCV) infection in children is 0.05%-0.4% in developed countries and 2%-5% in resource-limited settings, where inadequately tested blood products or un-sterile medical injections still remain important routes of infection. After the screening of blood donors, mother-to-child transmission (MTCT) of HCV has become the leading cause of pediatric infection, at a rate of 5%. Maternal HIV co-infection is a significant risk factor for MTCT and anti-HIV therapy during pregnancy seemingly can reduce the transmission rate of both viruses. Conversely, a high maternal viral load is an important, but not preventable risk factor, because at present no anti-HCV treatment can be administered to pregnant women to block viral replication. Caution is needed in adopting obstetric procedures, such as amniocentesis or internal fetal monitoring, that can favor fetal exposure to HCV contaminated maternal blood, though evidence is lacking on the real risk of single obstetric practices. Mode of delivery and type of feeding do not represent significant risk factors for MTCT. Therefore, there is no reason to offer elective caesarean section or discourage breast-feeding to HCV infected parturients. Information on the natural history of vertical HCV infection is limited. The primary infection is asymptomatic in infants. At least one quarter of infected children shows a spontaneous viral clearance (SVC) that usually occurs within 6 years of life. IL-28B polymorphims and genotype 3 infection have been associated with greater chances of SVC. In general, HCV progression is mild or moderate in children with chronic infection who grow regularly, though cases with marked liver fibrosis or hepatic failure have been described. Non-organ specific autoantibodies and cryoglobulins are frequently found in children with chronic infection, but autoimmune diseases or HCV associated extrahepatic manifestations are rare.

Pros and Cons: Usage of organs from donors infected with hepatitis C virus - Revision in the direct-acting antiviral era.

PubMed

Coilly, Audrey; Samuel, Didier

2016-01-01

Should organs from hepatitis C antibody positive donors (HCVD+) be used for transplantation? Organ shortage forces transplant teams to use donors with extended criteria. The decision to transplant a HCVD+ graft is a balance between the risk of transmission of a virus that could lead to end-stage liver diseases and the benefit of access to transplantation, specifically in patients with life-threatening disease. The other issue is the impact of HCV-related liver fibrosis in the donor graft on the long-term outcome in the recipient. Thus, the use of HCVD+ demonstrated a shorter meantime on the waiting list in kidney transplantation. When a HCVD+ graft is transplanted, the risk of HCV transmission depends on; 1) the quality of screening of the donor; 2) the presence of viral replication in the donor at the time of transplantation and the ability to detect it; and 3) the HCV status of the recipient but also the type of transplanted organ. In liver transplantation, the use of HCVD+ graft is usually restricted to recipients with a chronic HCV infection. Several reports showed some competition between HCV donor and recipient strain without deleterious impact on graft and patient survival. Controversies are still pending regarding the quality of the graft and the progression of fibrosis. The recent approval of direct-acting antiviral agents (DAA) dramatically changes the landscape of HCV infection treatment. After transplantation, combinations of DAA show high efficacy and good safety profile. In the near future, extensive use of DAA should reduce the number of HCVD+ with a positive HCV RNA, limiting the risk of transmission but also the number of patients on waiting lists for a disease related to HCV. Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Flow measurements in a water tunnel using a holocinematographic velocimeter

NASA Technical Reports Server (NTRS)

Weinstein, Leonard M.; Beeler, George B.

1987-01-01

Dual-view holographic movies were used to examine complex flows with full three-space and time resolution. This approach, which tracks the movement of small tracer particles in water, is termed holocinematographic velocimetry (HCV). A small prototype of a new water tunnel was used to demonstrate proof-of-concept for the HCV. After utilizing a conventional flow visualization apparatus with a laser light sheet to illuminate tracer particles to evaluate flow quality of the prototype tunnel, a simplified version of the HCV was employed to demonstrate the capabilities of the approach. Results indicate that a full-scale version of the water tunnel and a high performance version of the HCV should be able to check theoretical and numerical modeling of complex flows and examine the mechanisms operative in turbulent and vortex flow control concepts, providing an entirely unique instrument capable, for the first time, of simultaneous three-space and time measurements in turbulent flow.

CD81 expression is important for the permissiveness of Huh7 cell clones for heterogeneous hepatitis C virus infection.

PubMed

Akazawa, Daisuke; Date, Tomoko; Morikawa, Kenichi; Murayama, Asako; Miyamoto, Michiko; Kaga, Minako; Barth, Heidi; Baumert, Thomas F; Dubuisson, Jean; Wakita, Takaji

2007-05-01

Huh7 cells constitute a permissive cell line for cell culture of hepatitis C virus (HCV) particles. However, our Huh7 line shows limited permissiveness for HCV. Thus, in this study we set out to determine which host factors are important for conferring permissiveness. To analyze the limited permissiveness of our Huh7 cells, 70 clones were obtained after single-cell cloning of parental Huh7 cells. The cloned Huh7 cells exhibited various levels of HCV pseudoparticles and JFH-1 virus infection efficiency, and some clones were not permissive. A subgenomic replicon was then transfected into the cloned Huh7 cells. While the replication efficiencies differed among the cloned Huh7 cells, these efficiencies did not correlate with infectious permissibility. Flow cytometry showed that CD81, scavenger receptor class B type I, and low-density-lipoprotein receptor expression on the cell surfaces of the Huh7 clones differed among the clones. Interestingly, we found that all of the permissive cell clones expressed CD81 while the nonpermissive cell clones did not. To confirm the importance of CD81 expression for HCV permissiveness, CD81 was then transiently and stably expressed on a nonpermissive Huh7 cell clone, which was consequently restored to HCV infection permissiveness. Furthermore, permissiveness was down-regulated upon transfection of CD81 silencing RNA into a CD81-positive cell clone. In conclusion, CD81 expression is an important determinant of HCV permissiveness of Huh7 cell clones harboring different characteristics.

Inhibition of Hepatitis C Virus Production by Aptamers against the Core Protein

PubMed Central

Shi, Shali; Yu, Xiaoyan; Gao, Yimin; Xue, Binbin; Wu, Xinjiao; Wang, Xiaohong; Yang, Darong

2014-01-01

Hepatitis C virus (HCV) core protein is essential for virus assembly. HCV core protein was expressed and purified. Aptamers against core protein were raised through the selective evolution of ligands by the exponential enrichment approach. Detection of HCV infection by core aptamers and the antiviral activities of aptamers were characterized. The mechanism of their anti-HCV activity was determined. The data showed that selected aptamers against core specifically recognize the recombinant core protein but also can detect serum samples from hepatitis C patients. Aptamers have no effect on HCV RNA replication in the infectious cell culture system. However, the aptamers inhibit the production of infectious virus particles. Beta interferon (IFN-β) and interferon-stimulated genes (ISGs) are not induced in virally infected hepatocytes by aptamers. Domains I and II of core protein are involved in the inhibition of infectious virus production by the aptamers. V31A within core is the major resistance mutation identified. Further study shows that the aptamers disrupt the localization of core with lipid droplets and NS5A and perturb the association of core protein with viral RNA. The data suggest that aptamers against HCV core protein inhibit infectious virus production by disrupting the localization of core with lipid droplets and NS5A and preventing the association of core protein with viral RNA. The aptamers for core protein may be used to understand the mechanisms of virus assembly. Core-specific aptamers may hold promise for development as early diagnostic reagents and potential therapeutic agents for chronic hepatitis C. PMID:24307579

Ethanol affects hepatitis C pathogenesis: humanized SCID Alb-uPA mouse model.

PubMed

Osna, Natalia A; Kharbanda, Kusum K; Sun, Yimin; Simpson, Ronda L; Poluektova, Larisa E; Ganesan, Murali; Wisecarver, James L; Mercer, David F

2014-07-18

Alcohol consumption exacerbates the course of hepatitis C viral (HCV) infection, worsens outcomes and contributes to the development of chronic infection that exhibits low anti-viral treatment efficiency. The lack of suitable in vivo models makes HCV-ethanol studies very difficult. Here, we examine whether chimeric SCID Alb-uPA mice transplanted with human hepatocytes and infected with HCV develop worsening pathology when fed ethanol. After 5 weeks of feeding, such mice fed chow+water (control) or chow+20% ethanol in water (EtOH) diets mice developed oxidative stress, decreased proteasome activity and increased steatosis. Importantly, HCV(+) mice in the control group cleared HCV RNA after 5 weeks, while the infection persisted in EtOH-fed mice at the same or even higher levels compared with pre-feeding HCV RNA. We conclude that in chimeric SCID Alb-uPA mice, EtOH exposure causes the complex biochemical and histological changes typical for alcoholic liver injury. In addition, ethanol feeding delays the clearance of HCV RNA thereby generating persistent infection and promoting liver injury. Overall, this model is appropriate for conducting HCV-ethanol studies. Published by Elsevier Inc.

Advanced Molecular Surveillance of Hepatitis C Virus

PubMed Central

Gonçalves Rossi, Livia Maria; Escobar-Gutierrez, Alejandro; Rahal, Paula

2015-01-01

Hepatitis C virus (HCV) infection is an important public health problem worldwide. HCV exploits complex molecular mechanisms, which result in a high degree of intrahost genetic heterogeneity. This high degree of variability represents a challenge for the accurate establishment of genetic relatedness between cases and complicates the identification of sources of infection. Tracking HCV infections is crucial for the elucidation of routes of transmission in a variety of settings. Therefore, implementation of HCV advanced molecular surveillance (AMS) is essential for disease control. Accounting for virulence is also important for HCV AMS and both viral and host factors contribute to the disease outcome. Therefore, HCV AMS requires the incorporation of host factors as an integral component of the algorithms used to monitor disease occurrence. Importantly, implementation of comprehensive global databases and data mining are also needed for the proper study of the mechanisms responsible for HCV transmission. Here, we review molecular aspects associated with HCV transmission, as well as the most recent technological advances used for virus and host characterization. Additionally, the cornerstone discoveries that have defined the pathway for viral characterization are presented and the importance of implementing advanced HCV molecular surveillance is highlighted. PMID:25781918

NF90–NF45 is a selective RNA chaperone that rearranges viral and cellular riboswitches: biochemical analysis of a virus host factor activity

PubMed Central

Friedrich, Susann; Golbik, Ralph Peter

2017-01-01

Abstract The heterodimer NF90–NF45 is an RNA-binding protein complex that modulates the expression of various cellular mRNAs on the post-transcriptional level. Furthermore, it acts as a host factor that supports the replication of several RNA viruses. The molecular mechanisms underlying these activities have yet to be elucidated. Recently, we showed that the RNA-binding capabilities and binding specificity of NF90 considerably improves when it forms a complex with NF45. Here, we demonstrate that NF90 has a substrate-selective RNA chaperone activity (RCA) involving RNA annealing and strand displacement activities. The mechanism of the NF90-catalyzed RNA annealing was elucidated to comprise a combination of ‘matchmaking’ and compensation of repulsive charges, which finally results in the population of dsRNA products. Heterodimer formation with NF45 enhances ‘matchmaking’ of complementary ssRNAs and substantially increases the efficiency of NF90’s RCA. During investigations of the relevance of the NF90–NF45 RCA, the complex was shown to stimulate the first step in the RNA replication process of hepatitis C virus (HCV) in vitro and to stabilize a regulatory element within the mRNA of vascular endothelial growth factor (VEGF) by protein-guided changes of the RNAs’ structures. Thus, our study reveals how the intrinsic properties of an RNA-binding protein determine its biological activities. PMID:29040738

Experimental transmission of equine hepacivirus in horses as a model for hepatitis C virus

USDA-ARS?s Scientific Manuscript database

Equine hepacivirus (EHCV; non-primate hepacivirus) is a hepatotropic member of the Flaviviridae family that infects horses. Although EHCV is the closest known relative to hepatitis C virus (HCV), its complete replication kinetics in vivo have not been described, and direct evidence that it causes he...

Performance of the New Aptima HCV Quant Dx Assay in Comparison to the Cobas TaqMan HCV2 Test for Use with the High Pure System in Detection and Quantification of Hepatitis C Virus RNA in Plasma or Serum.

PubMed

Schalasta, Gunnar; Speicher, Andrea; Börner, Anna; Enders, Martin

2016-04-01

Quantitating the level of hepatitis C virus (HCV) RNA is the standard of care for monitoring HCV-infected patients during treatment. The performances of commercially available assays differ for precision, limit of detection, and limit of quantitation (LOQ). Here, we compare the performance of the Hologic Aptima HCV Quant Dx assay (Aptima) to that of the Roche Cobas TaqMan HCV test, version 2.0, using the High Pure system (HPS/CTM), considered a reference assay since it has been used in trials defining clinical decision points in patient care. The assays' performance characteristics were assessed using HCV RNA reference panels and plasma/serum from chronically HCV-infected patients. The agreement between the assays for the 3 reference panels was good, with a difference in quantitation values of <0.5 log. High concordance was demonstrated between the assays for 245 clinical samples (kappa = 0.80; 95% confidence interval [CI], 0.720 to 0.881); however, Aptima detected and/or quantitated 20 samples that HPS/CTM did not detect, while Aptima did not detect 1 sample that was quantitated by HPS/CTM. For the 165 samples quantitated by both assays, the values were highly correlated (R= 0.98;P< 0.0001). The linearity of quantitation from concentrations of 1.4 to 6 log was excellent for both assays for all HCV genotypes (GT) tested (GT 1a, 1b, 2b, and 3a) (R(2)> 0.99). The assays had similar levels of total and intra-assay variability across all genotypes at concentrations from 1,000 to 25 IU/ml. Aptima had a greater analytical sensitivity, quantitating more than 50% of replicates at 25-IU/ml target. Aptima showed performance characteristics comparable to those of HPS/CTM and increased sensitivity, making it suitable for use as a clinical diagnostic tool on the fully automated Panther platform. Copyright © 2016 Schalasta et al.

Genetic heterogeneity of the hepatitis C virus.

PubMed

Bukh, J; Miller, R H; Purcell, R H

1995-01-01

Hepatitis C virus (HCV) is an important etiological agent in the development of chronic liver diseases such as chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The virus, identified only recently, contains a single-stranded RNA genome of positive polarity, is distantly related to pestiviruses and flaviviruses, and has been classified as the first member of a third genus within the family Flaviviridae. Extensive analysis of HCV genomic sequences demonstrated that this virus possesses significant genetic heterogeneity. Different regions of the viral genome demonstrate a varying degree of heterogeneity; the regions coding for the putative envelope proteins are the most variable sites between different isolates. Furthermore, HCV circulates as a quasispecies in the host. During the course of acute and chronic infection, the sequence composition of the HCV population in one patient has been found to change sequentially with an extremely high rate of nonconserved nucleotide changes in the hypervariable region I (HVR1) of HCV. Such sequence changes alter the antigenicity of the epitopes coded within HVR1 so that these are not always recognized by preexisting antibodies. It has been suggested that this could represent one mechanism by which HCV evades host immune surveillance and may account for the high rate of chronicity observed in such infections. Continuous viral replication may, in turn, lead to the development of chronic liver disease, including HCC, in infected individuals. To date, at least nine major genetic groups (genotypes 1-9) and more than 30 subgroups of HCV have been recognized based on genetic differences. A distinct difference has been observed in the genotype distribution in Africa compared with other continents. Recent data have suggested a difference in pathogenesis and in the outcome of interferon therapy in individuals infected with HCV of certain genotypes. For example, genotype 1b (II) seems to be associated with more severe liver disease, including HCC, and with a poorer response to interferon therapy. The extensive genetic heterogeneity of HCV may have serious implications for the diagnosis, treatment and prevention of hepatitis C as well as in understanding the biology of infection by this important human pathogen.

Anti-hepatitis C virus activity and toxicity of type III phosphatidylinositol-4-kinase beta inhibitors.

PubMed

Lamarche, M J; Borawski, J; Bose, A; Capacci-Daniel, C; Colvin, R; Dennehy, M; Ding, J; Dobler, M; Drumm, J; Gaither, L A; Gao, J; Jiang, X; Lin, K; McKeever, U; Puyang, X; Raman, P; Thohan, S; Tommasi, R; Wagner, K; Xiong, X; Zabawa, T; Zhu, S; Wiedmann, B

2012-10-01

Type III phosphatidylinositol-4-kinase beta (PI4KIIIβ) was previously implicated in hepatitis C virus (HCV) replication by small interfering RNA (siRNA) depletion and was therefore proposed as a novel cellular target for the treatment of hepatitis C. Medicinal chemistry efforts identified highly selective PI4KIIIβ inhibitors that potently inhibited the replication of genotype 1a and 1b HCV replicons and genotype 2a virus in vitro. Replicon cells required more than 5 weeks to reach low levels of 3- to 5-fold resistance, suggesting a high resistance barrier to these cellular targets. Extensive in vitro profiling of the compounds revealed a role of PI4KIIIβ in lymphocyte proliferation. Previously proposed functions of PI4KIIIβ in insulin secretion and the regulation of several ion channels were not perturbed with these inhibitors. Moreover, PI4KIIIβ inhibitors were not generally cytotoxic as demonstrated across hundreds of cell lines and primary cells. However, an unexpected antiproliferative effect in lymphocytes precluded their further development for the treatment of hepatitis C.

Anti-Hepatitis C Virus Activity and Toxicity of Type III Phosphatidylinositol-4-Kinase Beta Inhibitors

PubMed Central

LaMarche, M. J.; Borawski, J.; Bose, A.; Capacci-Daniel, C.; Colvin, R.; Dennehy, M.; Ding, J.; Dobler, M.; Drumm, J.; Gaither, L. A.; Gao, J.; Jiang, X.; Lin, K.; McKeever, U.; Puyang, X.; Raman, P.; Thohan, S.; Tommasi, R.; Wagner, K.; Xiong, X.; Zabawa, T.; Zhu, S.

2012-01-01

Type III phosphatidylinositol-4-kinase beta (PI4KIIIβ) was previously implicated in hepatitis C virus (HCV) replication by small interfering RNA (siRNA) depletion and was therefore proposed as a novel cellular target for the treatment of hepatitis C. Medicinal chemistry efforts identified highly selective PI4KIIIβ inhibitors that potently inhibited the replication of genotype 1a and 1b HCV replicons and genotype 2a virus in vitro. Replicon cells required more than 5 weeks to reach low levels of 3- to 5-fold resistance, suggesting a high resistance barrier to these cellular targets. Extensive in vitro profiling of the compounds revealed a role of PI4KIIIβ in lymphocyte proliferation. Previously proposed functions of PI4KIIIβ in insulin secretion and the regulation of several ion channels were not perturbed with these inhibitors. Moreover, PI4KIIIβ inhibitors were not generally cytotoxic as demonstrated across hundreds of cell lines and primary cells. However, an unexpected antiproliferative effect in lymphocytes precluded their further development for the treatment of hepatitis C. PMID:22825118

Zinc is a potent and specific inhibitor of IFN-λ3 signalling

PubMed Central

Read, Scott A.; O'Connor, Kate S.; Suppiah, Vijay; Ahlenstiel, Chantelle L. E.; Obeid, Stephanie; Cook, Kristina M.; Cunningham, Anthony; Douglas, Mark W.; Hogg, Philip J.; Booth, David; George, Jacob; Ahlenstiel, Golo

2017-01-01

Lambda interferons (IFNL, IFN-λ) are pro-inflammatory cytokines important in acute and chronic viral infection. Single-nucleotide polymorphisms rs12979860 and rs8099917 within the IFNL gene locus predict hepatitis C virus (HCV) clearance, as well as inflammation and fibrosis progression in viral and non-viral liver disease. The underlying mechanism, however, is not defined. Here we show that the rs12979860 CC genotype correlates with increased hepatic metallothionein expression through increased systemic zinc levels. Zinc interferes with IFN-λ3 binding to IFNL receptor 1 (IFNLR1), resulting in decreased antiviral activity and increased viral replication (HCV, influenza) in vitro. HCV patients with high zinc levels have low hepatocyte antiviral and inflammatory gene expression and high viral loads, confirming the inhibitory role of zinc in vivo. We provide the first evidence that zinc can act as a potent and specific inhibitor of IFN-λ3 signalling and highlight its potential as a target of therapeutic intervention for IFN-λ3-mediated chronic disease. PMID:28513591

Direct Acting Anti-hepatitis C Virus Drugs: Clinical Pharmacology and Future Direction

PubMed Central

Geddawy, Ayman; Ibrahim, Yasmine F.; Elbahie, Nabil M.; Ibrahim, Mohammad A.

2017-01-01

Abstract Chronic hepatitis C virus (HCV) infection is a leading cause of chronic liver disease. The introduction of direct acting antiviral agents (DAAs) for its treatment represents a major advance in terms of sustained virologic response (SVR) rates and adverse effect profiles. Mechanistically, DAAs inhibit specific HCV non-structural proteins (NS) that are vital for its replication. Boceprevir, telaprevir, simeprevir, asunaprevir, grazoprevir and paritaprevir are NS3/4A inhibitors. Ombitasvir, ledipasvir, daclatasvir, elbasvir and velpatasvir are NS5A inhibitors. Sofosbuvir and dasabuvir are NS5B inhibitors. Currently, a combination of two or more DAAs is the corner stone for the treatment of HCV infection. However, the success of DAA therapy is facing several challenges, including the potential of drug-drug interactions and resistant variance. Moreover, the shortage of relevant clinical pharmacological data and drug interaction regarding DAA is a clinical concern. The present review discusses the clinical pharmacology of DAAs with special emphasis on drug-drug interaction. PMID:28680834

The HCV and HIV coinfected patient: what have we learned about pathophysiology?

PubMed

Talal, Andrew H; Canchis, P Wilfredo; Jacobson, Ira

2002-02-01

Hepatitis C virus (HCV) infection is an important problem in individuals who are also infected with HIV. HCV infection is very common in HIV-infected individuals, occurring in approximately one quarter to one third of this group, presumably as a consequence of shared routes of transmission related to virologic and pathogenic aspects of the viral infections. Although both are single-stranded RNA viruses and share similar epidemiologic properties, there are many important differences. Although the quantity of HIV RNA in plasma is an important prognostic determinant of HIV infection, this has not been shown with HCV. A direct relationship is apparent between HIV-related destruction of CD4 cells and the clinical consequences of the disease resulting from immunodeficiency. The pathogenesis of HCV, which occurs as a consequence of hepatic fibrosis, is much more complex. The hepatic stellate cell, the major producer of the extracellular matrix protein, is the main contributor to hepatic fibrosis, but the mechanism by which HCV induces hepatic fibrosis remains unclear. Treatment of HCV is increasingly important in HIV-infected patients due to improved HIV-associated morbidity and mortality and due to the frequency with which HCV occurs in patients with HIV-HCV coinfection. Timing of treatment initiation, management of side effects, and possible effects of anti-HCV therapy on HIV are among the issues that need consideration. Also, because several issues concerning HCV are unique to coinfected patients, further research is needed to determine optimal management of HCV in this setting.

Single-Genome Sequencing of Hepatitis C Virus in Donor-Recipient Pairs Distinguishes Modes and Models of Virus Transmission and Early Diversification.

PubMed

Li, Hui; Stoddard, Mark B; Wang, Shuyi; Giorgi, Elena E; Blair, Lily M; Learn, Gerald H; Hahn, Beatrice H; Alter, Harvey J; Busch, Michael P; Fierer, Daniel S; Ribeiro, Ruy M; Perelson, Alan S; Bhattacharya, Tanmoy; Shaw, George M

2016-01-01

Despite the recent development of highly effective anti-hepatitis C virus (HCV) drugs, the global burden of this pathogen remains immense. Control or eradication of HCV will likely require the broad application of antiviral drugs and development of an effective vaccine. A precise molecular identification of transmitted/founder (T/F) HCV genomes that lead to productive clinical infection could play a critical role in vaccine research, as it has for HIV-1. However, the replication schema of these two RNA viruses differ substantially, as do viral responses to innate and adaptive host defenses. These differences raise questions as to the certainty of T/F HCV genome inferences, particularly in cases where multiple closely related sequence lineages have been observed. To clarify these issues and distinguish between competing models of early HCV diversification, we examined seven cases of acute HCV infection in humans and chimpanzees, including three examples of virus transmission between linked donors and recipients. Using single-genome sequencing (SGS) of plasma vRNA, we found that inferred T/F sequences in recipients were identical to viral sequences in their respective donors. Early in infection, HCV genomes generally evolved according to a simple model of random evolution where the coalescent corresponded to the T/F sequence. Closely related sequence lineages could be explained by high multiplicity infection from a donor whose viral sequences had undergone a pretransmission bottleneck due to treatment, immune selection, or recent infection. These findings validate SGS, together with mathematical modeling and phylogenetic analysis, as a novel strategy to infer T/F HCV genome sequences. Despite the recent development of highly effective, interferon-sparing anti-hepatitis C virus (HCV) drugs, the global burden of this pathogen remains immense. Control or eradication of HCV will likely require the broad application of antiviral drugs and the development of an effective vaccine, which could be facilitated by a precise molecular identification of transmitted/founder (T/F) viral genomes and their progeny. We used single-genome sequencing to show that inferred HCV T/F sequences in recipients were identical to viral sequences in their respective donors and that viral genomes generally evolved early in infection according to a simple model of random sequence evolution. Altogether, the findings validate T/F genome inferences and illustrate how T/F sequence identification can illuminate studies of HCV transmission, immunopathogenesis, drug resistance development, and vaccine protection, including sieving effects on breakthrough virus strains. Copyright © 2015 Li et al.

Reduced sTWEAK and Increased sCD163 Levels in HIV-Infected Patients: Modulation by Antiretroviral Treatment, HIV Replication and HCV Co-Infection

PubMed Central

Beltrán, Luis M.; García Morillo, José S.; Egido, Jesús; Noval, Manuel Leal; Ferrando-Martinez, Sara; Blanco-Colio, Luis M.; Genebat, Miguel; Villar, José R.; Moreno-Luna, Rafael; Moreno, Juan Antonio

2014-01-01

Background Patients infected with the human immunodeficiency virus (HIV) have an increased risk of cardiovascular disease due to increased inflammation and persistent immune activation. CD163 is a macrophage scavenger receptor that is involved in monocyte-macrophage activation in HIV-infected patients. CD163 interacts with TWEAK, a member of the TNF superfamily. Circulating levels of sTWEAK and sCD163 have been previously associated with cardiovascular disease, but no previous studies have fully analyzed their association with HIV. Objective The aim of this study was to analyze circulating levels of sTWEAK and sCD163 as well as other known markers of inflammation (hsCRP, IL-6 and sTNFRII) and endothelial dysfunction (sVCAM-1 and ADMA) in 26 patients with HIV before and after 48 weeks of antiretroviral treatment (ART) and 23 healthy subjects. Results Patients with HIV had reduced sTWEAK levels and increased sCD163, sVCAM-1, ADMA, hsCRP, IL-6 and sTNFRII plasma concentrations, as well as increased sCD163/sTWEAK ratio, compared with healthy subjects. Antiretroviral treatment significantly reduced the concentrations of sCD163, sVCAM-1, hsCRP and sTNFRII, although they remained elevated when compared with healthy subjects. Antiretroviral treatment had no effect on the concentrations of ADMA and sTWEAK, biomarkers associated with endothelial function. The use of protease inhibitors as part of antiretroviral therapy and the presence of HCV-HIV co-infection and/or active HIV replication attenuated the ART-mediated decrease in sCD163 plasma concentrations. Conclusion HIV-infected patients showed a proatherogenic profile characterized by increased inflammatory, immune-activation and endothelial-dysfunction biomarkers that partially improved after ART. HCV-HIV co-infection and/or active HIV replication enhanced immune activation despite ART. PMID:24594990

Impact of hepatitis C virus co-infection on HIV patients before and after highly active antiretroviral therapy: an immunological and clinical chemistry observation, Addis Ababa, Ethiopia.

PubMed

Taye, Solomon; Lakew, Mekuria

2013-05-17

Hepatitis C virus (HCV) is an RNA virus which has been known to cause acute and chronic necro-inflammatory disease of the liver. It is the leading cause of end-stage liver disease and hepatocellular carcinoma. HIV is known to have a negative impact on the natural disease outcome and immune response of HCV infection, whereas the reverse remains unclear. We evaluated the impact of HCV co-infection on recovery of CD4+ and CD8+ T-cells and liver enzyme levels before and after initiation of highly active antiretroviral therapy (HAART) in HIV/HCV co-infected patients. A hospital-based, observational, prospective cohort study design was used for this study. Pre-antiretroviral treatment (Pre-ART) and under HAART HIV mono-infected and HCV/HIV co-infected individuals who are under regular follow-up were recruited for this study. 387 blood samples were collected from volunteer, known HIV positive Ethiopian patients and screened for HCV. Twenty five HCV/HIV co-infected patients were prospectively followed for four years. CD4+ and CD8+ T-cells and liver enzyme levels were determined annually for each of the participant. The prevalence of HCV/HIV co-infection in this study was 6.5%. Both HCV/HIV co-infected and HIV mono-infected under HAART groups showed CD4+ recovery (343 Vs 426; P < 0.004, OR = 4.97, 95% CI = 2.41 to 10.27) respectively; but, the recovery rate was higher in mono-infected (80 Vs 426) than co-infected group (148 Vs 343). The recovery and/or decline pattern of CD8+ T-cells was the same with that of CD4+. In 75% of co-infected groups, the mean alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were above the upper limit of normal reference range. Analyses restricted to individuals who initiated HAART and pre-ART showed similar results. We found that CD4+ T-cell recovery was negatively affected by the presence of ongoing HCV replication in under HAART co-infected individuals and fast decline of CD4+ T-cells in pre-ART patients. It was also associated with increased ALT and AST enzyme levels in both HAART initiated and treatment naïve co-infected patients.

Infection of Hepatocytes With HCV Increases Cell Surface Levels of Heparan Sulfate Proteoglycans, Uptake of Cholesterol and Lipoprotein, and Virus Entry by Up-regulating SMAD6 and SMAD7.

PubMed

Zhang, Fang; Sodroski, Catherine; Cha, Helen; Li, Qisheng; Liang, T Jake

2017-01-01

The signaling molecule and transcriptional regulator SMAD6, which inhibits the transforming growth factor β signaling pathway, is required for infection of hepatocytes by hepatitis C virus (HCV). We investigated the mechanisms by which SMAD6 and another inhibitory SMAD (SMAD7) promote HCV infection in human hepatoma cells and hepatocytes. We infected Huh7 and Huh7.5.1 cells and primary human hepatocytes with Japanese fulminant hepatitis-1 (JFH1) HCV cell culture system (HCVcc). We then measured HCV binding, intracellular levels of HCV RNA, and expression of target genes. We examined HCV entry in HepG2/microRNA (miR) 122/CD81 cells, which support entry and replication of HCV, were transfected these cells with small interfering RNAs targeting inhibitory SMADs to analyze gene expression profiles. Uptake of labeled low-density lipoprotein (LDL) and cholesterol was measured. Cell surface proteins were quantified by flow cytometry. We obtained liver biopsy samples from 69 patients with chronic HCV infection and 19 uninfected individuals (controls) and measured levels of syndecan 1 (SDC1), SMAD7, and SMAD6 messenger RNAs (mRNAs). Small interfering RNA knockdown of SMAD6 blocked the binding and infection of hepatoma cell lines and primary human hepatocytes by HCV, whereas SMAD6 overexpression increased HCV infection. We found levels of mRNAs encoding heparan sulfate proteoglycans (HSPGs), particularly SDC1 mRNA, and cell surface levels of heparan sulfate to be reduced in cells after SMAD6 knockdown. SMAD6 knockdown also reduced transcription of genes encoding lipoprotein and cholesterol uptake receptors, including the LDL receptor (LDLR), the very LDLR, and the scavenger receptor class B member 1 in hepatocytes; knockdown of SMAD6 also inhibited cell uptake of cholesterol and lipoprotein. Overexpression of SMAD6 increased the expression of these genes. Similar effects were observed with knockdown and overexpression of SMAD7. In addition, HCV infection of cells increased the expression of SMAD6, which required the activity of nuclear factor-κB, but not transforming growth factor β. Liver tissues from patients with chronic HCV infection had significantly higher levels of SMAD6, SMAD7, and HSPG mRNAs than controls. In studies of hepatoma cell lines and primary human hepatocytes, we found that infection with HCV leads to activation of nuclear factor-κB, resulting in increased expression of SMAD6 and SMAD7. Up-regulation of SMAD6 and SMAD7 induces the expression of HSPGs, such as SDC1, as well as LDLR, very LDLR, and the scavenger receptor class B member 1, which promote HCV entry and propagation, as well as cellular uptake of cholesterol and lipoprotein. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

NS3 protease resistance-associated substitutions in liver tissue and plasma samples from patients infected by hepatitis C virus genotype 1A or 1B.

PubMed

Morsica, Giulia; Andolina, Andrea; Merli, Marco; Messina, Emanuela; Hasson, Hamid; Lazzarin, Adriano; Uberti-Foppa, Caterina; Bagaglio, Sabrina

2017-08-01

The presence of naturally occurring resistance-associated substitutions (RASs) in the HCV-protease domain has been poorly investigated in the liver, the main site of HCV replication. We evaluated the natural resistance of the virus to NS3 protease inhibitors in liver tissue and plasma samples taken from HCV-infected patients. RASs were investigated by means of viral population sequencing in liver tissue samples from 18 HCV-infected patients harbouring genotype 1a or genotype 1b; plasma samples from 12 of these patients were also available for virological investigation. A discordant genotype was found in two of the 12 patients (16.6%) who provided samples from both compartments. Sequence analysis of the NS3 protease domain showed the presence of RASs in four of the 18 liver tissue samples (22.2%), two of which showed cross-resistance to protease inhibitors in clinical use or phase 2-3 trials. The analysis of the 12 paired tissues and plasma samples excluded the presence of RASs in the plasma compartment. The dominance of discordant genotypes in the paired liver and plasma samples of some HCV-infected patients suggests mixed infection possibly leading to the selective advantage of different genotype in the two compartments. The presence of RASs at intra-hepatic level is not uncommon and may lead to the early emergence of cross-resistant strains.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kong, Leopold; Giang, Erick; Robbins, Justin B.

Hepatitis C virus (HCV) infects more than 2% of the global population and is a leading cause of liver cirrhosis, hepatocellular carcinoma, and end-stage liver diseases. Circulating HCV is genetically diverse, and therefore a broadly effective vaccine must target conserved T- and B-cell epitopes of the virus. Human mAb HCV1 has broad neutralizing activity against HCV isolates from at least four major genotypes and protects in the chimpanzee model from primary HCV challenge. The antibody targets a conserved antigenic site (residues 412-423) on the virus E2 envelope glycoprotein. Two crystal structures of HCV1 Fab in complex with an epitope peptidemore » at 1.8-{angstrom} resolution reveal that the epitope is a {beta}-hairpin displaying a hydrophilic face and a hydrophobic face on opposing sides of the hairpin. The antibody predominantly interacts with E2 residues Leu{sup 413} and Trp{sup 420} on the hydrophobic face of the epitope, thus providing an explanation for how HCV isolates bearing mutations at Asn{sup 415} on the same binding face escape neutralization by this antibody. The results provide structural information for a neutralizing epitope on the HCV E2 glycoprotein and should help guide rational design of HCV immunogens to elicit similar broadly neutralizing antibodies through vaccination.« less

Analysis of INF-gamma, TNF-alpha and dendritic cells to predict hepatitis C virus recurrence in liver transplant patients.

PubMed

Ocaña, L; Cos, J; Quer, J; Bilbao, I; Palou, E; Parra, R; Sauleda, S; Esteban, J I; Guàrdia, J; Massuet, L I; Margarit, C

2005-11-01

Hepatitis C virus (HCV) infection is one of the leading causes of chronic liver disease and the reason for more than 50% of liver transplantations (OLT). Recurrent HCV infection occurs in almost all transplant recipients and has an unfavorable course. Although immunosuppressive agents are necessary to avoid allograft rejection, these drugs may favor viral replication facilitating viral-mediated graft injury. To predict the evolution of two HCV(+) patients who underwent OLT, we studied INF-gamma and TNF-alpha production and the maturation capacity of dendritic cells (DCs) at three time points: before transplantation (Pre-Tx) and at 2 (2M) and 6 (6M) months after transplantation. Cytometric bead assays were used to quantify INF-gamma and TNF-alpha production in the supernates of mixed leukocyte reactions (MLR) between spleen cells from the liver donor and CD4(+) cells from the recipients. Immature and mature DCs were generated in vitro from patient monocytes. The one patient who experienced recurrent HCV showed loss of CD4(+) responses to donor antigens and INF-gamma and TNF-alpha production after OLT. In contrast, the other patient maintained detectable levels of these cytokines after OLT. It was possible to generate mature DCs from monocytes with the aid of CD40L in both cases, but decreased expression of HLA-DR, CD80, and CD86 markers was observed upon posttransplantation analyses in the patient with recurrent HCV. Loss of the proliferative response as well as INF-gamma and TNF-alpha production, together with a decreased HLA-DR, CD80, and CD86 (markers of mature DCs), indicated an inadequate immune response to viral progression in the liver transplant recipient with relapsing HCV infection.

Natural prevalence of resistance-associated variants in hepatitis C virus NS5A in genotype 3a-infected people who inject drugs in Germany.

PubMed

Walker, Andreas; Siemann, Holger; Groten, Svenja; Ross, R Stefan; Scherbaum, Norbert; Timm, Jörg

2015-09-01

People who inject drugs (PWID) are the most important risk group for incident Hepatitis C virus (HCV) infection. In PWID in Europe HCV genotype 3a is highly prevalent. Unfortunately, many of the recently developed directly acting antiviral drugs against HCV (DAAs) are suboptimal for treatment of this genotype. Detection of resistance-associated variants (RAV) in genotype 3a may help to optimize treatment decisions, however, robust protocols for amplification and sequencing of HCV NS5A as an important target for treatment of genotype 3a are currently lacking. The aim of this study was to establish a protocol for sequencing of HCV NS5A in genotype 3a and to determine the frequency of RAVs in treatment-naïve PWID living in Germany. The full NS5A region was amplified and sequenced from 110 HCV genotype 3a infected PWID using an in-house PCR protocol. With the established protocol the complete NS5A region was successfully amplified and sequenced from 110 out of 112 (98.2%) genotype 3a infected PWID. Phylogenetic analysis of sequences from PWID together with unrelated genotype 3a sequences from a public database showed a scattered distribution without geographic clustering. Viral polymorphisms A30K and Y93H known to confer resistance in a GT3a replication model were present in 8 subjects (7.2%). A protocol for amplification of nearly all GT3a samples was successfully established. Substitutions conferring resistance to NS5A inhibitors were detected in a few treatment-naive PWID. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of monoclonal antibodies that specifically recognize the palm subdomain of hepatitis C virus nonstructural protein 5B polymerase.

PubMed

Ingravallo, P; Lahser, F; Xia, E; Sodowich, B; Lai, V C; Hong, Z; Zhong, W

2001-06-01

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) which plays an essential role in viral RNA replication. Antibodies that specifically recognize NS5B will have utilities in monitoring NS5B production and subcellular localization, as well as in structure-function studies. In this report, three mouse monoclonal antibodies (mAbs), 16A9C9, 16D9A4 and 20A12C7, against a recombinant NS5B protein (genotype 1a, H-77 strain) were produced. These mAbs specifically recognize HCV NS5B, but not RdRps of polivirus (PV), bovine viral diarrhea virus (BVDV) or GB virus B (GBV-B). The mAbs can readily detect NS5B in cellular lysates of human osteosarcoma Saos2 cells constitutively expressing the nonstructural region of HCV (NS3-NS4A-NS4B-NS5A-NS5B). NS5B proteins of different HCV genotypes/subtypes (1a, 1b, 2a, 2c, 5a) showed varied affinity for these mAbs. Interestingly, the epitopes for the mAbs were mapped to the palm subdomain (amino acid 188-370) of the HCV RdRp as determined by immunoblotting analysis of a panel of HCV/GBV-B chimeric NS5B proteins. The binding site was mapped between amino acid 231 and 267 of NS5B for 16A9C9, and between 282 and 372 for 16D9A4 and 20A12C7. Furthermore, these mAbs showed no inhibitory effect on the NS5B polymerase activity in vitro.

Characterization of B cell lymphoma in patients with Sjögren's syndrome and hepatitis C virus infection.

PubMed

Ramos-Casals, Manuel; la Civita, Luca; de Vita, Salvatore; Solans, Roser; Luppi, Mario; Medina, Francisco; Caramaschi, Paola; Fadda, Patrizia; de Marchi, Ginevra; Lopez-Guillermo, Armando; Font, Josep

2007-02-15

To characterize the clinical and immunologic patterns of expression, response to therapy, and outcome of patients with Sjögren's syndrome (SS) and associated hepatitis C virus (HCV) infection who developed B cell lymphoma. Various international reference centers constituted a multicenter study group with the purpose of creating a registry of patients with SS-HCV who developed B cell lymphoma. A protocol form was used to record the main characteristics of SS, chronic HCV infection, and B cell lymphoma. Twenty-five patients with SS-HCV with B cell lymphoma were included in the registry. There were 22 (88%) women and 3 (12%) men (mean age 55, 58, and 61 years at SS, HCV infection, and lymphoma diagnosis, respectively). The main extraglandular SS manifestations were cutaneous vasculitis in 15 (60%) patients and peripheral neuropathy in 12 (48%); the main immunologic features were positive rheumatoid factor (RF) in 24 (96%) and type II cryoglobulins in 20 (80%). The main histologic subtypes were mucosa-associated lymphoid tissue (MALT) lymphoma in 11 (44%) patients, diffuse large B cell lymphoma in 6 (24%), and follicular center cell lymphoma in 6 (24%). Fifteen (60%) patients had an extranodal primary location, most frequently in the parotid gland (5 patients), liver (4 patients), and stomach (4 patients). Twelve (52%) of 23 patients died after a median followup from the time of lymphoma diagnosis of 4 years, with lymphoma progression being the most frequent cause of death. Survival differed significantly between the main types of B cell lymphoma. Patients with SS-HCV and B cell lymphoma are clinically characterized by a high frequency of parotid enlargement and vasculitis, an immunologic pattern overwhelmingly dominated by the presence of RF and mixed type II cryoglobulins, a predominance of MALT lymphomas, and an elevated frequency of primary extranodal involvement in organs in which HCV replicates (exocrine glands, liver, and stomach).

A Concerted Action of Hepatitis C Virus P7 and Nonstructural Protein 2 Regulates Core Localization at the Endoplasmic Reticulum and Virus Assembly

PubMed Central

Boson, Bertrand; Granio, Ophélia; Bartenschlager, Ralf; Cosset, François-Loïc

2011-01-01

Hepatitis C virus (HCV) assembly remains a poorly understood process. Lipid droplets (LDs) are thought to act as platforms for the assembly of viral components. The JFH1 HCV strain replicates and assembles in association with LD-associated membranes, around which viral core protein is predominantly detected. In contrast, despite its intrinsic capacity to localize to LDs when expressed individually, we found that the core protein of the high-titer Jc1 recombinant virus was hardly detected on LDs of cell culture-grown HCV (HCVcc)-infected cells, but was mainly localized at endoplasmic reticulum (ER) membranes where it colocalized with the HCV envelope glycoproteins. Furthermore, high-titer cell culture-adapted JFH1 virus, obtained after long-term culture in Huh7.5 cells, exhibited an ER-localized core in contrast to non-adapted JFH1 virus, strengthening the hypothesis that ER localization of core is required for efficient HCV assembly. Our results further indicate that p7 and NS2 are HCV strain-specific factors that govern the recruitment of core protein from LDs to ER assembly sites. Indeed, using expression constructs and HCVcc recombinant genomes, we found that p7 is sufficient to induce core localization at the ER, independently of its ion-channel activity. Importantly, the combined expression of JFH1 or Jc1 p7 and NS2 induced the same differential core subcellular localization detected in JFH1- vs. Jc1-infected cells. Finally, results obtained by expressing p7-NS2 chimeras between either virus type indicated that compatibilities between the p7 and the first NS2 trans-membrane domains is required to induce core-ER localization and assembly of extra- and intra-cellular infectious viral particles. In conclusion, we identified p7 and NS2 as key determinants governing the subcellular localization of HCV core to LDs vs. ER and required for initiation of the early steps of virus assembly. PMID:21814513

HCV Diversity among Chinese and Burmese IDUs in Dehong, Yunnan, China

PubMed Central

Chen, Xin; Duo, Lin; Li, Peilu; Zheng, Yong-Tang; Zhang, Chiyu

2016-01-01

HCV transmission is closely associated with drug-trafficking routes in China. Dehong, a prefecture of Yunnan, is the important trade transfer station linking Southeast Asia and China, as well as the drug-trafficking channel linking “Golden triangle” and other regions of China and surrounding countries. In this study, we investigated the HCV genotype diversity among IDUs in Dehong based on 259 HCV positive samples from 118 Chinese and 141 Burmese IDUs. HCV genotypes were determined based on the phylogenies of C/E2 and NS5B genomic sequences. Six HCV subtypes, including 1a, 1b, 3a, 3b, 6n and 6u, were detected. Interestingly, 4 HCV sequences from Burmese IDUs did not cluster with any known HCV subtypes, but formed a well-supported independent clade in the phylogenetic trees of both C/E2 and NS5B, suggesting a potential new HCV subtype circulating in Dehong. Subtype 3b was the predominant subtype, followed by subtypes 6n and 6u. Comparison showed that Dehong had a unique pattern of HCV subtype distribution, obviously different from other regions of China. In particular, HCV subtypes 6u and the potential new HCV subtype had a relatively high prevalence in Dehong, but were rarely detected in other regions of China. There was no significant difference in HCV subtype distribution between Burmese and Chinese IDUs. Few HCV sequences from Burmese and Chinese IDUs clustered together to form transmission clusters. Furthermore, about half of HCV sequences from Burmese IDUs formed small transmission clusters, significantly higher than that from Chinese IDUs (p<0.01). These suggest that the Chinese and Burmese IDUs were relatively isolated from each other in injection drug use behavior and the Burmese IDUs might prefer to inject drugs themselves together. The unique genotype distribution and complex diversity of genotype 6 among IDUs may be associated with the special geographical position of Dehong. PMID:27657722

Induction of Broad CD4+ and CD8+ T-Cell Responses and Cross- Neutralizing Antibodies against Hepatitis C Virus by Vaccination with Th1-Adjuvanted Polypeptides Followed by Defective Alphaviral Particles Expressing Envelope Glycoproteins gpE1 and gpE2 and Nonstructural Proteins 3, 4, and 5▿ †

PubMed Central

Lin, Yinling; Kwon, Taewoo; Polo, John; Zhu, Yi-Fei; Coates, Stephen; Crawford, Kevin; Dong, Christine; Wininger, Mark; Hall, John; Selby, Mark; Coit, Doris; Medina-Selby, Angelica; McCoin, Colin; Ng, Philip; Drane, Debbie; Chien, David; Han, Jang; Vajdy, Michael; Houghton, Michael

2008-01-01

Broad, multispecific CD4+ and CD8+ T-cell responses to the hepatitis C virus (HCV), as well as virus-cross-neutralizing antibodies, are associated with recovery from acute infection and may also be associated in chronic HCV patients with a favorable response to antiviral treatment. In order to recapitulate all of these responses in an ideal vaccine regimen, we have explored the use of recombinant HCV polypeptides combined with various Th1-type adjuvants and replication-defective alphaviral particles encoding HCV proteins in various prime/boost modalities in BALB/c mice. Defective chimeric alphaviral particles derived from the Sindbis and Venezuelan equine encephalitis viruses encoding either the HCV envelope glycoprotein gpE1/gpE2 heterodimer (E1E2) or nonstructural proteins 3, 4, and 5 (NS345) elicited strong CD8+ T-cell responses but low CD4+ T helper responses to these HCV gene products. In contrast, recombinant E1E2 glycoproteins adjuvanted with MF59 containing a CpG oligonucleotide elicited strong CD4+ T helper responses but no CD8+ T-cell responses. A recombinant NS345 polyprotein also stimulated strong CD4+ T helper responses but no CD8+ T-cell responses when adjuvanted with Iscomatrix containing CpG. Optimal elicitation of broad CD4+ and CD8+ T-cell responses to E1E2 and NS345 was obtained by first priming with Th1-adjuvanted proteins and then boosting with chimeric, defective alphaviruses expressing these HCV genes. In addition, this prime/boost regimen resulted in the induction of anti-E1E2 antibodies capable of cross-neutralizing heterologous HCV isolates in vitro. This vaccine formulation and regimen may therefore be optimal in humans for protection against this highly heterogeneous global pathogen. PMID:18508900

Interaction between the NS4B amphipathic helix, AH2, and charged lipid headgroups alters membrane morphology and AH2 oligomeric state--Implications for the Hepatitis C virus life cycle.

PubMed

Ashworth Briggs, Esther L; Gomes, Rafael G B; Elhussein, Malaz; Collier, William; Findlow, I Stuart; Khalid, Syma; McCormick, Chris J; Williamson, Philip T F

2015-08-01

The non-structural protein 4B (NS4B) from Hepatitis C virus (HCV) plays a pivotal role in the remodelling of the host cell's membranes, required for the formation of the viral replication complex where genome synthesis occurs. NS4B is an integral membrane protein that possesses a number of domains vital for viral replication. Structural and biophysical studies have revealed that one of these, the second amphipathic N-terminal helix (AH2), plays a key role in these remodelling events. However, there is still limited understanding of the mechanism through which AH2 promotes these changes. Here we report on solid-state NMR and molecular dynamics studies that demonstrate that AH2 promotes the clustering of negatively charged lipids within the bilayer, a process that reduces the strain within the bilayer facilitating the remodelling of the lipid bilayer. Furthermore, the presence of negatively charged lipids within the bilayer appears to promote the disassociation of AH2 oligomers, highlighting a potential role for lipid recruitment in regulating NS protein interactions. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Proteome Analysis of Liver Cells Expressing a Full- Length Hepatitis C Virus (HCV) Replicon and Biopsy Specimens of Posttransplantation Liver from HCV-Infected Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobs, Jon M.; Diamond, Deborah L.; Chan, Eric Y.

2005-06-01

The development of a reproducible model system for the study of Hepatitis C virus (HCV) infection has the potential to significantly enhance the study of virus-host interactions and provide future direction for modeling the pathogenesis of HCV. While there are studies describing global gene expression changes associated with HCV infection, changes in the proteome have not been characterized. We report the first large scale proteome analysis of the highly permissive Huh-7.5 cell line containing a full length HCV replicon. We detected > 4,400 proteins in this cell line, including HCV replicon proteins, using multidimensional liquid chromatographic (LC) separations coupled tomore » mass spectrometry (MS). The set of Huh-7.5 proteins confidently identified is, to our knowledge, the most comprehensive yet reported for a human cell line. Consistent with the literature, a comparison of Huh-7.5 cells (+) and (-) the HCV replicon identified expression changes of proteins involved in lipid metabolism. We extended these analyses to liver biopsy material from HCV-infected patients where > 1,500 proteins were detected from 2 {micro}g protein lysate using the Huh-7.5 protein database and the accurate mass and time (AMT) tag strategy. These findings demonstrate the utility of multidimensional proteome analysis of the HCV replicon model system for assisting the determination of proteins/pathways affected by HCV infection. Our ability to extend these analyses to the highly complex proteome of small liver biopsies with limiting protein yields offers the unique opportunity to begin evaluating the clinical significance of protein expression changes associated with HCV infection.« less

Aspartic acid based nucleoside phosphoramidate prodrugs as potent inhibitors of hepatitis C virus replication.

PubMed

Maiti, Munmun; Maiti, Mohitosh; Rozenski, Jef; De Jonghe, Steven; Herdewijn, Piet

2015-05-14

In view of a persistent threat to mankind, the development of nucleotide-based prodrugs against hepatitis C virus (HCV) is considered as a constant effort in many medicinal chemistry groups. In an attempt to identify novel nucleoside phosphoramidate analogues for improving the anti-HCV activity, we have explored, for the first time, aspartic acid (Asp) and iminodiacetic acid (IDA) esters as amidate counterparts by considering three 2'-C-methyl containing nucleosides, 2'-C-Me-cytidine, 2'-C-Me-uridine and 2'-C-Me-2'-fluoro-uridine. Synthesis of these analogues required protection for the vicinal diol functionality of the sugar moiety and the amino group of the cytidine nucleoside to regioselectively perform phosphorylation reaction at the 5'-hydroxyl group. Anti-HCV data demonstrate that the Asp-based phosphoramidates are ∼550 fold more potent than the parent nucleosides. The inhibitory activity of the Asp-ProTides was higher than the Ala-ProTides, suggesting that Asp would be a potential amino acid candidate to be considered for developing novel antiviral prodrugs.

Structure-Based Design of Hepatitis C Virus Vaccines That Elicit Neutralizing Antibody Responses to a Conserved Epitope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, Brian G.; Boucher, Elisabeth N.; Piepenbrink, Kurt H.

Despite recent advances in therapeutic options, hepatitis C virus (HCV) remains a severe global disease burden, and a vaccine can substantially reduce its incidence. Due to its extremely high sequence variability, HCV can readily escape the immune response; thus, an effective vaccine must target conserved, functionally important epitopes. Using the structure of a broadly neutralizing antibody in complex with a conserved linear epitope from the HCV E2 envelope glycoprotein (residues 412 to 423; epitope I), we performed structure-based design of immunogens to induce antibody responses to this epitope. This resulted in epitope-based immunogens based on a cyclic defensin protein, asmore » well as a bivalent immunogen with two copies of the epitope on the E2 surface. We solved the X-ray structure of a cyclic immunogen in complex with the HCV1 antibody and confirmed preservation of the epitope conformation and the HCV1 interface. Mice vaccinated with our designed immunogens produced robust antibody responses to epitope I, and their serum could neutralize HCV. Notably, the cyclic designs induced greater epitope-specific responses and neutralization than the native peptide epitope. Beyond successfully designing several novel HCV immunogens, this study demonstrates the principle that neutralizing anti-HCV antibodies can be induced by epitope-based, engineered vaccines and provides the basis for further efforts in structure-based design of HCV vaccines. IMPORTANCEHepatitis C virus is a leading cause of liver disease and liver cancer, with approximately 3% of the world's population infected. To combat this virus, an effective vaccine would have distinct advantages over current therapeutic options, yet experimental vaccines have not been successful to date, due in part to the virus's high sequence variability leading to immune escape. In this study, we rationally designed several vaccine immunogens based on the structure of a conserved epitope that is the target of broadly neutralizing antibodies.In vivoresults in mice indicated that these antigens elicited epitope-specific neutralizing antibodies, with various degrees of potency and breadth. These promising results suggest that a rational design approach can be used to generate an effective vaccine for this virus.« less

Evolution of a Cell Culture-Derived Genotype 1a Hepatitis C Virus (H77S.2) during Persistent Infection with Chronic Hepatitis in a Chimpanzee

PubMed Central

Yi, MinKyung; Hu, Fengyu; Joyce, Michael; Saxena, Vikas; Welsch, Christoph; Chavez, Deborah; Guerra, Bernadette; Yamane, Daisuke; Veselenak, Ronald; Pyles, Rick; Walker, Christopher M.; Tyrrell, Lorne; Bourne, Nigel; Lanford, Robert E.

2014-01-01

ABSTRACT Persistent infection is a key feature of hepatitis C virus (HCV). However, chimpanzee infections with cell culture-derived viruses (JFH1 or related chimeric viruses that replicate efficiently in cell culture) have been limited to acute-transient infections with no pathogenicity. Here, we report persistent infection with chronic hepatitis in a chimpanzee challenged with cell culture-derived genotype 1a virus (H77S.2) containing 6 cell culture-adaptive mutations. Following acute-transient infection with a chimeric H77/JFH1 virus (HJ3-5), intravenous (i.v.) challenge with 106 FFU H77S.2 virus resulted in immediate seroconversion and, following an unusual 4- to 6-week delay, persistent viremia accompanied by alanine aminotransferase (ALT) elevation, intrahepatic innate immune responses, and diffuse hepatopathy. This first persistent infection with cell culture-produced HCV provided a unique opportunity to assess evolution of cell culture-adapted virus in vivo. Synonymous and nonsynonymous nucleotide substitution rates were greatest during the first 8 weeks of infection. Of 6 cell culture-adaptive mutations in H77S.2, Q1067R (NS3) had reverted to Q1067 and S2204I (NS5A) was replaced by T2204 within 8 weeks of infection. By 62 weeks, 4 of 6 mutations had reverted to the wild-type sequence, and all reverted to the wild-type sequence by 194 weeks. The data suggest H77S.2 virus has greater potential for persistence and pathogenicity than JFH1 and demonstrate both the capacity of a nonfit virus to persist for weeks in the liver in the absence of detectable viremia as well as strong selective pressure against cell culture-adaptive mutations in vivo. IMPORTANCE This study shows that mutations promoting the production of infectious genotype 1a HCV in cell culture have the opposite effect and attenuate replication in the liver of the only fully permissive animal species other than humans. It provides the only example to date of persistent infection in a chimpanzee challenged with cell culture-produced virus and provides novel insight into the forces shaping molecular evolution of that virus during 5 years of persistent infection. It demonstrates that a poorly fit virus can replicate for weeks within the liver in the absence of detectable viremia, an observation that expands current concepts of HCV pathogenesis and that is relevant to relapses observed with direct-acting antiviral therapies. PMID:24429362

Clinical Laboratory Testing in the Era of Directly Acting Antiviral Therapies for Hepatitis C

PubMed Central

Wilson, Eleanor M.; Rosenthal, Elana S.; Kattakuzhy, Sarah; Tang, Lydia

2016-01-01

SUMMARY Directly acting antiviral (DAA) combination therapies for chronic hepatitis C virus (HCV) infection are highly effective, but treatment decisions remain complex. Laboratory testing is important to evaluate a range of viral, host, and pharmacological factors when considering HCV treatment, and patients must be monitored during and after therapy for safety and to assess the viral response. In this review, we discuss the laboratory tests relevant for the treatment of HCV infection in the era of DAA therapy, grouped according to viral and host factors. PMID:27795306

A 2'-deoxy-2'-fluoro-2'-C-methyl uridine cyclopentyl carbocyclic analog and its phosphoramidate prodrug as inhibitors of HCV NS5B polymerase.

PubMed

Liu, Jian; Du, Jinfa; Wang, Peiyuan; Nagarathnam, Dhanapalan; Espiritu, Christine L; Bao, Haiying; Murakami, Eisuke; Furman, Phillip A; Sofia, Michael J

2012-04-01

The 2 '-deoxy-2 '-fluoro-2 '-C-methyluridine nucleotide prodrug, PSI-7851 and its single diastereomer PSI-7977 have displayed potent antiviral activity against hepatitis C virus in clinical trials, and PSI-7977 is currently in Phase III studies. As part of our SAR study of the 2 '-deoxy-2 '-fluoro-2 '- C-methyl class of nucleosides, we prepared the cyclopentyl carbocyclic uridine analog 11 and its phosphoramidate prodrug 15. Both 11 and 15 were shown not to inhibit HCV replication. This lack of activity might be attributed to the inability of the monophosphate to be converted to the corresponding diphosphate or triphosphate or the inactivity of triphosphate of 11 as an inhibitor of the polymerase.

Cryo-electron microscopy and three-dimensional reconstructions of hepatitis C virus particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu Xuekui; Qiao Ming; Atanasov, Ivo

2007-10-10

The structural details of hepatitis C virus (HCV) have been elusive because of the lack of a robust tissue culture system for producing an adequate amount of virions from infectious sources for in-depth three-dimensional (3D) structural analysis. Using both negative-stain and cryo-electron microscopy (cryoEM), we show that HCV virions isolated from cell culture have a rather uniform size of 500 A in diameter and that recombinantly expressed HCV-like particles (HCV-LPs) have similar morphologic, biophysical and antigenic features in spite of the varying sizes of the particles. 3D reconstructions were obtained from HCV-LPs with the same size as the HCV virionsmore » in the presence and absence of monoclonal antibodies bound to the E1 glycoprotein. The 3D reconstruction of HCV-LP reveals a multilayered architecture, with smooth outer-layer densities arranged in a 'fishbone' configuration. Reconstruction of the particles in complex with anti-E1 antibodies shows that sites of the E1 epitope are exposed and surround the 5-, 3- and 2-fold axes. The binding pattern of the anti-E1 antibody and the fitting of the structure of the dengue virus E glycoprotein into our 3D reconstructions further suggest that the HCV-LP E1 and E2 proteins form a tetramer (or dimer of heterodimers) that corresponds morphologically and functionally to the flavivirus E homodimer. This first 3D structural analysis of HCV particles offers important insights into the elusive mechanisms of HCV assembly and maturation.« less

Host genetic factors associated with hepatocellular carcinoma in patients with hepatitis C virus infection: A systematic review.

PubMed

Walker, A J; Peacock, C J; Pedergnana, V; Irving, W L

2018-05-01

Hepatitis C virus (HCV)-infected patients are at risk of developing hepatocellular carcinoma (HCC). Individuals at heightened risk could be targeted by intensive follow-up surveillance. We have conducted a systematic review of the literature to identify host genetic predisposition to HCC in HCV-infected patients. A comprehensive search of Medline and Embase databases was performed, and the strength of evidence of associations for each gene on development of HCC was evaluated. We identified 166 relevant studies, relating to 137 different genes, or combinations thereof. Seventeen genes were classified as having "good" evidence of an association, a significant association was observed for 37 genes but this finding had not yet been replicated, 56 genes had mixed or limited evidence of an association, and 27 genes showed no association. IFNL3/4, TNF-α and PNPLA3 genes had the most evidence of an association. There was, however, considerable heterogeneity in study design and data quality. In conclusion, we identified a number of genes with evidence of association with HCC, but also a need for more standardized approaches to address this clinically critical question. It is important to consider the underlying mechanism of these relationships and which are confounded by the presence of other HCC risk factors and response to therapy. We also identified many genes where the evidence of association is contradictory or requires replication, as well as a number where associations have been studied but no evidence found. These findings should help to direct future studies on host genetic predisposition to HCC in HCV-infected patients. © 2018 The Authors. Journal of Viral Hepatitis Published by John Wiley & Sons Ltd.

Empirical fitness models for hepatitis C virus immunogen design

NASA Astrophysics Data System (ADS)

Hart, Gregory R.; Ferguson, Andrew L.

2015-12-01

Hepatitis C virus (HCV) afflicts 170 million people worldwide, 2%-3% of the global population, and kills 350 000 each year. Prophylactic vaccination offers the most realistic and cost effective hope of controlling this epidemic in the developing world where expensive drug therapies are not available. Despite 20 years of research, the high mutability of the virus and lack of knowledge of what constitutes effective immune responses have impeded development of an effective vaccine. Coupling data mining of sequence databases with spin glass models from statistical physics, we have developed a computational approach to translate clinical sequence databases into empirical fitness landscapes quantifying the replicative capacity of the virus as a function of its amino acid sequence. These landscapes explicitly connect viral genotype to phenotypic fitness, and reveal vulnerable immunological targets within the viral proteome that can be exploited to rationally design vaccine immunogens. We have recovered the empirical fitness landscape for the HCV RNA-dependent RNA polymerase (protein NS5B) responsible for viral genome replication, and validated the predictions of our model by demonstrating excellent accord with experimental measurements and clinical observations. We have used our landscapes to perform exhaustive in silico screening of 16.8 million T-cell immunogen candidates to identify 86 optimal formulations. By reducing the search space of immunogen candidates by over five orders of magnitude, our approach can offer valuable savings in time, expense, and labor for experimental vaccine development and accelerate the search for a HCV vaccine. Abbreviations: HCV—hepatitis C virus, HLA—human leukocyte antigen, CTL—cytotoxic T lymphocyte, NS5B—nonstructural protein 5B, MSA—multiple sequence alignment, PEG-IFN—pegylated interferon.

Hepatitis C Virus Nucleotide Inhibitors PSI-352938 and PSI-353661 Exhibit a Novel Mechanism of Resistance Requiring Multiple Mutations within Replicon RNA▿†

PubMed Central

Lam, Angela M.; Espiritu, Christine; Bansal, Shalini; Micolochick Steuer, Holly M.; Zennou, Veronique; Otto, Michael J.; Furman, Phillip A.

2011-01-01

PSI-352938, a cyclic phosphate nucleotide, and PSI-353661, a phosphoramidate nucleotide, are prodrugs of β-d-2′-deoxy-2′-α-fluoro-2′-β-C-methylguanosine-5′-monophosphate. Both compounds are metabolized to the same active 5′-triphosphate, PSI-352666, which serves as an alternative substrate inhibitor of the NS5B RNA-dependent RNA polymerase during HCV replication. PSI-352938 and PSI-353661 retained full activity against replicons containing the S282T substitution, which confers resistance to certain 2′-substituted nucleoside/nucleotide analogs. PSI-352666 was also similarly active against both wild-type and S282T NS5B polymerases. In order to identify mutations that confer resistance to these compounds, in vitro selection studies were performed using HCV replicon cells. While no resistant genotype 1a or 1b replicons could be selected, cells containing genotype 2a JFH-1 replicons cultured in the presence of PSI-352938 or PSI-353661 developed resistance to both compounds. Sequencing of the NS5B region identified a number of amino acid changes, including S15G, R222Q, C223Y/H, L320I, and V321I. Phenotypic evaluation of these mutations indicated that single amino acid changes were not sufficient to significantly reduce the activity of PSI-352938 and PSI-353661. Instead, a combination of three amino acid changes, S15G/C223H/V321I, was required to confer a high level of resistance. No cross-resistance exists between the 2′-F-2′-C-methylguanosine prodrugs and other classes of HCV inhibitors, including 2′-modified nucleoside/-tide analogs such as PSI-6130, PSI-7977, INX-08189, and IDX-184. Finally, we determined that in genotype 1b replicons, the C223Y/H mutation failed to support replication, and although the A15G/C223H/V321I triple mutation did confer resistance to PSI-352938 and PSI-353661, this mutant replicated at only about 10% efficiency compared to the wild type. PMID:21957306

pH-Dependent Conformational Changes in the HCV NS3 Protein Modulate Its ATPase and Helicase Activities

PubMed Central

Ventura, Gustavo Tavares; da Costa, Emmerson Corrêa Brasil; Capaccia, Anne Miranda; Mohana-Borges, Ronaldo

2014-01-01

The hepatitis C virus (HCV) infects 170 to 200 million people worldwide and is, therefore, a major health problem. The lack of efficient treatments that specifically target the viral proteins or RNA and its high chronicity rate make hepatitis C the cause of many deaths and hepatic transplants annually. The NS3 protein is considered an important target for the development of anti-HCV drugs because it is composed of two domains (a serine protease in the N-terminal portion and an RNA helicase/NTPase in the C-terminal portion), which are essential for viral replication and proliferation. We expressed and purified both the NS3 helicase domain (NS3hel) and the full-length NS3 protein (NS3FL) and characterized pH-dependent structural changes associated with the increase in their ATPase and helicase activities at acidic pH. Using intrinsic fluorescence experiments, we have observed that NS3hel was less stable at pH 6.4 than at pH 7.2. Moreover, binding curves using an extrinsic fluorescent probe (bis-ANS) and ATPase assays performed under different pH conditions demonstrated that the hydrophobic clefts of NS3 are significantly more exposed to the aqueous medium at acidic pH. Using fluorescence spectroscopy and anisotropy assays, we have also observed more protein interaction with DNA upon pH acidification, which suggests that the hydrophobic clefts exposure on NS3 might be related to a loss of stability that could lead it to adopt a more open conformation. This conformational change at acidic pH would stimulate both its ATPase and helicase activities, as well as its ability to bind DNA. Taken together, our results indicate that the NS3 protein adopts a more open conformation due to acidification from pH 7.2 to 6.4, resulting in a more active form at a pH that is found near Golgi-derived membranes. This increased activity could better allow NS3 to carry out its functions during HCV replication. PMID:25551442

Hepatitis B Virus Reactivation Associated With Direct-Acting Antiviral Therapy for Chronic Hepatitis C Virus: A Review of Cases Reported to the U.S. Food and Drug Administration Adverse Event Reporting System.

PubMed

Bersoff-Matcha, Susan J; Cao, Kelly; Jason, Mihaela; Ajao, Adebola; Jones, S Christopher; Meyer, Tamra; Brinker, Allen

2017-06-06

Direct-acting antiviral agents (DAAs) are used increasingly to treat hepatitis C virus (HCV) infection. Reports were published recently on hepatitis B virus (HBV) reactivation (HBV-R) in patients with HBV-HCV co-infection. Hepatitis B virus reactivation, defined as an abrupt increase in HBV replication in patients with inactive or resolved HBV infection, may result in clinically significant hepatitis. To assess whether HBV-R is a safety concern in patients receiving HCV DAAs. Descriptive case series. U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). 29 patients with HBV-R receiving HCV DAAs. Clinical and laboratory data. The FDA identified 29 unique reports of HBV-R in patients receiving DAAs from 22 November 2013 to 15 October 2016. Two cases resulted in death and 1 case in liver transplantation. Patients in whom HBV-R developed were heterogeneous regarding HCV genotype, DAAs received, and baseline HBV characteristics. At baseline, 9 patients had a detectable HBV viral load, 7 had positive results on hepatitis B surface antigen (HBsAg) testing and had an undetectable HBV viral load, and 3 had negative results on HBsAg testing and had an undetectable HBV viral load. For the remaining 10 patients, data points were not reported or the data were uninterpretable. Despite provider knowledge of baseline HBV, HBV-R diagnosis and treatment were delayed in 7 cases and possibly 7 others. The quality of information varied among reports. Because reporting is voluntary, HBV-R associated with DAAs likely is underreported. Hepatitis B virus reactivation is a newly identified safety concern in patients with HBV-HCV co-infection treated with DAAs. Patients with a history of HBV require clinical monitoring while receiving DAA therapy. Studies would help determine the risk factors for HBV-R, define monitoring frequency, and identify patients who may benefit from HBV prophylaxis and treatment. DAAs remain a safe and highly effective treatment for the management of HCV infection. None.

Ebselen inhibits hepatitis C virus NS3 helicase binding to nucleic acid and prevents viral replication.

PubMed

Mukherjee, Sourav; Weiner, Warren S; Schroeder, Chad E; Simpson, Denise S; Hanson, Alicia M; Sweeney, Noreena L; Marvin, Rachel K; Ndjomou, Jean; Kolli, Rajesh; Isailovic, Dragan; Schoenen, Frank J; Frick, David N

2014-10-17

The hepatitis C virus (HCV) nonstructural protein 3 (NS3) is both a protease, which cleaves viral and host proteins, and a helicase that separates nucleic acid strands, using ATP hydrolysis to fuel the reaction. Many antiviral drugs, and compounds in clinical trials, target the NS3 protease, but few helicase inhibitors that function as antivirals have been reported. This study focuses on the analysis of the mechanism by which ebselen (2-phenyl-1,2-benzisoselenazol-3-one), a compound previously shown to be a HCV antiviral agent, inhibits the NS3 helicase. Ebselen inhibited the abilities of NS3 to unwind nucleic acids, to bind nucleic acids, and to hydrolyze ATP, and about 1 μM ebselen was sufficient to inhibit each of these activities by 50%. However, ebselen had no effect on the activity of the NS3 protease, even at 100 times higher ebselen concentrations. At concentrations below 10 μM, the ability of ebselen to inhibit HCV helicase was reversible, but prolonged incubation of HCV helicase with higher ebselen concentrations led to irreversible inhibition and the formation of covalent adducts between ebselen and all 14 cysteines present in HCV helicase. Ebselen analogues with sulfur replacing the selenium were just as potent HCV helicase inhibitors as ebselen, but the length of the linker between the phenyl and benzisoselenazol rings was critical. Modifications of the phenyl ring also affected compound potency over 30-fold, and ebselen was a far more potent helicase inhibitor than other, structurally unrelated, thiol-modifying agents. Ebselen analogues were also more effective antiviral agents, and they were less toxic to hepatocytes than ebselen. Although the above structure-activity relationship studies suggest that ebselen targets a specific site on NS3, we were unable to confirm binding to either the NS3 ATP binding site or nucleic acid binding cleft by examining the effects of ebselen on NS3 proteins lacking key cysteines.

Analysis of hepatitis C NS5A resistance associated polymorphisms using ultra deep single molecule real time (SMRT) sequencing.

PubMed

Bergfors, Assar; Leenheer, Daniël; Bergqvist, Anders; Ameur, Adam; Lennerstrand, Johan

2016-02-01

Development of Hepatitis C virus (HCV) resistance against direct-acting antivirals (DAAs), including NS5A inhibitors, is an obstacle to successful treatment of HCV when DAAs are used in sub-optimal combinations. Furthermore, it has been shown that baseline (pre-existing) resistance against DAAs is present in treatment naïve-patients and this will potentially complicate future treatment strategies in different HCV genotypes (GTs). Thus the aim was to detect low levels of NS5A resistant associated variants (RAVs) in a limited sample set of treatment-naïve patients of HCV GT1a and 3a, since such polymorphisms can display in vitro resistance as high as 60000 fold. Ultra-deep single molecule real time (SMRT) sequencing with the Pacific Biosciences (PacBio) RSII instrument was used to detect these RAVs. The SMRT sequencing was conducted on ten samples; three of them positive with Sanger sequencing (GT1a Q30H and Y93N, and GT3a Y93H), five GT1a samples, and two GT3a non-positive samples. The same methods were applied to the HCV GT1a H77-plasmid in a dilution series, in order to determine the error rates of replication, which in turn was used to determine the limit of detection (LOD), as defined by mean + 3SD, of minority variants down to 0.24%. We found important baseline NS5A RAVs at levels between 0.24 and 0.5%, which could potentially have clinical relevance. This new method with low level detection of baseline RAVs could be useful in predicting the most cost-efficient combination of DAA treatment, and reduce the treatment duration for an HCV infected individual. Copyright © 2015 Elsevier B.V. All rights reserved.

Removal of Hepatitis C Virus-Infected Cells by a Zymogenized Bacterial Toxin

PubMed Central

Shapira, Assaf; Shapira, Shiran; Gal-Tanamy, Meital; Zemel, Romy; Tur-Kaspa, Ran; Benhar, Itai

2012-01-01

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and has become a global health threat. No HCV vaccine is currently available and treatment with antiviral therapy is associated with adverse side effects. Moreover, there is no preventive therapy for recurrent hepatitis C post liver transplantation. The NS3 serine protease is necessary for HCV replication and represents a prime target for developing anti HCV therapies. Recently we described a therapeutic approach for eradication of HCV infected cells that is based on protein delivery of two NS3 protease-activatable recombinant toxins we named “zymoxins”. These toxins were inactivated by fusion to rationally designed inhibitory peptides via NS3-cleavable linkers. Once delivered to cells where NS3 protease is present, the inhibitory peptide is removed resulting in re-activation of cytotoxic activity. The zymoxins we described suffered from two limitations: they required high levels of protease for activation and had basal activities in the un-activated form that resulted in a narrow potential therapeutic window. Here, we present a solution that overcame the major limitations of the “first generation zymoxins” by converting MazF ribonuclease, the toxic component of the E. coli chromosomal MazEF toxin-antitoxin system, into an NS3-activated zymoxin that is introduced to cells by means of gene delivery. We constructed an expression cassette that encodes for a single polypeptide that incorporates both the toxin and a fragment of its potent natural antidote, MazE, linked via an NS3-cleavable linker. While covalently paired to its inhibitor, the ribonuclease is well tolerated when expressed in naïve, healthy cells. In contrast, activating proteolysis that is induced by even low levels of NS3, results in an eradication of NS3 expressing model cells and HCV infected cells. Zymoxins may thus become a valuable tool in eradicating cells infected by intracellular pathogens that express intracellular proteases. PMID:22359682

Targeted Induction of Interferon-λ in Humanized Chimeric Mouse Liver Abrogates Hepatotropic Virus Infection

PubMed Central

Kameyama, Takeshi; Tokunaga, Yuko; Nishito, Yasumasa; Hirabayashi, Kazuko; Yano, Junichi; Ochiya, Takahiro; Tateno, Chise; Tanaka, Yasuhito; Mizokami, Masashi; Tsukiyama-Kohara, Kyoko; Inoue, Kazuaki; Yoshiba, Makoto; Takaoka, Akinori; Kohara, Michinori

2013-01-01

Background & Aims The interferon (IFN) system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV) and hepatitis B virus (HBV). Methods This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC). Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs) in the livers and sera of these humanized chimeric mice. Results Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level) of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic) tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS) and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1), suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. Conclusions These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection. PMID:23555725

Targeted induction of interferon-λ in humanized chimeric mouse liver abrogates hepatotropic virus infection.

PubMed

Nakagawa, Shin-ichiro; Hirata, Yuichi; Kameyama, Takeshi; Tokunaga, Yuko; Nishito, Yasumasa; Hirabayashi, Kazuko; Yano, Junichi; Ochiya, Takahiro; Tateno, Chise; Tanaka, Yasuhito; Mizokami, Masashi; Tsukiyama-Kohara, Kyoko; Inoue, Kazuaki; Yoshiba, Makoto; Takaoka, Akinori; Kohara, Michinori

2013-01-01

The interferon (IFN) system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV) and hepatitis B virus (HBV). This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC). Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs) in the livers and sera of these humanized chimeric mice. Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level) of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic) tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS) and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1), suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection.

Ribonucleoside Analogue That Blocks Replication of Bovine Viral Diarrhea and Hepatitis C Viruses in Culture

PubMed Central

Stuyver, Lieven J.; Whitaker, Tony; McBrayer, Tamara R.; Hernandez-Santiago, Brenda I.; Lostia, Stefania; Tharnish, Phillip M.; Ramesh, Mangala; Chu, Chung K.; Jordan, Robert; Shi, Junxing; Rachakonda, Suguna; Watanabe, Kyoichi A.; Otto, Michael J.; Schinazi, Raymond F.

2003-01-01

A base-modified nucleoside analogue, β-d-N4-hydroxycytidine (NHC), was found to have antipestivirus and antihepacivirus activities. This compound inhibited the production of cytopathic bovine viral diarrhea virus (BVDV) RNA in a dose-dependant manner with a 90% effective concentration (EC90) of 5.4 μM, an observation that was confirmed by virus yield assays (EC90 = 2 μM). When tested for hepatitis C virus (HCV) replicon RNA reduction in Huh7 cells, NHC had an EC90 of 5 μM on day 4. The HCV RNA reduction was incubation time and nucleoside concentration dependent. The in vitro antiviral effect of NHC was additive with recombinant alpha interferon-2a and could be prevented by the addition of exogenous cytidine and uridine but not of other natural ribo- or 2′-deoxynucleosides. When HCV RNA replicon cells were cultured in the presence of increasing concentrations of NHC (up to 40 μM) for up to 45 cell passages, no resistant replicon was selected. Similarly, resistant BVDV could not be selected after 20 passages. NHC was phosphorylated to the triphosphate form in Huh7 cells, but in cell-free HCV NS5B assays, synthetic NHC-triphosphate (NHC-TP) did not inhibit the polymerization reaction. Instead, NHC-TP appeared to serve as a weak alternative substrate for the viral polymerase, thereby changing the mobility of the product in polyacrylamide electrophoresis gels. We speculate that incorporated nucleoside analogues with the capacity of changing the thermodynamics of regulatory secondary structures (with or without introducing mutations) may represent an important class of new antiviral agents for the treatment of RNA virus infections, especially HCV. PMID:12499198

Potential for all-trans retinoic acid (tretinoin) to enhance interferon-alpha treatment response in chronic myelogenous leukemia, melanoma, myeloma and renal cell carcinoma.

PubMed

Kast, Richard E

2008-10-01

This note mechanistically accounts for recent unexplained findings that all-trans retinoic acid (ATRA, also termed tretinoin) exerts an anti-viral effect against hepatitis C virus (HCV) in chronically infected patients, in whom ATRA also showed synergy with interferon-alpha. How HCV replication was suppressed was unclear. Both effects of ATRA can be accounted for by ATRA's upregulation of RIG protein, an 18 kDa product of retinoic induced gene-1. Increased RIG then couples ATRA to increased Type 1 interferons' production. Details of this mechanism predict that ATRA will similarly augment interferon-a activity in treating chronic myelogenous leukemia, melanoma, myeloma and renal cell carcinoma and that the addition of ribavirin and/or bexarotene will each incrementally enhance interferon-a responses in these cancers.

Hepatitis C - Assessment to Treatment Trial (HepCATT) in primary care: study protocol for a cluster randomised controlled trial.

PubMed

Roberts, Kirsty; Macleod, John; Metcalfe, Chris; Simon, Joanne; Horwood, Jeremy; Hollingworth, William; Marlowe, Sharon; Gordon, Fiona H; Muir, Peter; Coleman, Barbara; Vickerman, Peter; Harrison, Graham I; Waldron, Cherry-Ann; Irving, William; Hickman, Matthew

2016-07-29

Public Health England (PHE) estimates that there are upwards of 160,000 individuals in England and Wales with chronic hepatitis C virus (HCV) infection, but until now only around 100,000 laboratory diagnoses have been reported to PHE and of these 28,000 have been treated. Targeted case-finding in primary care is estimated to be cost-effective; however, there has been no robust randomised controlled trial evidence available of specific interventions. Therefore, this study aims to develop and conduct a complex intervention within primary care and to evaluate this approach using a cluster randomised controlled trial. A total of 46 general practices in South West England will be randomised in a 1:1 ratio to receive either a complex intervention comprising: educational training on HCV for the practice; poster and leaflet display in the practice waiting rooms to raise awareness and encourage opportunistic testing; a HCV risk prediction algorithm based on information on possible risk markers in the electronic patient record run using Audit + software (BMJ Informatica). The audit will then be used to recall and offer patients a HCV test. Control practices will follow usual care. The effectiveness of the intervention will be measured by comparing number and rates of HCV testing, the number and proportion of patients testing positive, onward referral, rates of specialist assessment and treatment in control and intervention practices. Intervention costs and health service utilisation will be recorded to estimate the NHS cost per new HCV diagnosis and new HCV patient initiating treatment. Longer-term cost-effectiveness of the intervention in improving quality-adjusted life years (QALYs) will be extrapolated using a pre-existing dynamic health economic model. Patients' and health care workers' experiences and acceptability of the intervention will be explored through semi-structured qualitative interviews. This trial has the potential to make an important impact on patient care and will provide high-quality evidence to help general practitioners make important decisions on HCV testing and onward referral. If found to be effective and cost-effective the intervention is readily scalable and can be used to support the implementation of NICE recommendations on HCV case-finding. ISRCTN61788850 . Registered on 24 April 2015; Protocol Version: 2.0, 22 May 2015.

Statistical Linkage Analysis of Substitutions in Patient-Derived Sequences of Genotype 1a Hepatitis C Virus Nonstructural Protein 3 Exposes Targets for Immunogen Design

PubMed Central

Quadeer, Ahmed A.; Louie, Raymond H. Y.; Shekhar, Karthik; Chakraborty, Arup K.; Hsing, I-Ming

2014-01-01

ABSTRACT Chronic hepatitis C virus (HCV) infection is one of the leading causes of liver failure and liver cancer, affecting around 3% of the world's population. The extreme sequence variability of the virus resulting from error-prone replication has thwarted the discovery of a universal prophylactic vaccine. It is known that vigorous and multispecific cellular immune responses, involving both helper CD4+ and cytotoxic CD8+ T cells, are associated with the spontaneous clearance of acute HCV infection. Escape mutations in viral epitopes can, however, abrogate protective T-cell responses, leading to viral persistence and associated pathologies. Despite the propensity of the virus to mutate, there might still exist substitutions that incur a fitness cost. In this paper, we identify groups of coevolving residues within HCV nonstructural protein 3 (NS3) by analyzing diverse sequences of this protein using ideas from random matrix theory and associated methods. Our analyses indicate that one of these groups comprises a large percentage of residues for which HCV appears to resist multiple simultaneous substitutions. Targeting multiple residues in this group through vaccine-induced immune responses should either lead to viral recognition or elicit escape substitutions that compromise viral fitness. Our predictions are supported by published clinical data, which suggested that immune genotypes associated with spontaneous clearance of HCV preferentially recognized and targeted this vulnerable group of residues. Moreover, mapping the sites of this group onto the available protein structure provided insight into its functional significance. An epitope-based immunogen is proposed as an alternative to the NS3 epitopes in the peptide-based vaccine IC41. IMPORTANCE Despite much experimental work on HCV, a thorough statistical study of the HCV sequences for the purpose of immunogen design was missing in the literature. Such a study is vital to identify epistatic couplings among residues that can provide useful insights for designing a potent vaccine. In this work, ideas from random matrix theory were applied to characterize the statistics of substitutions within the diverse publicly available sequences of the genotype 1a HCV NS3 protein, leading to a group of sites for which HCV appears to resist simultaneous substitutions possibly due to deleterious effect on viral fitness. Our analysis leads to completely novel immunogen designs for HCV. In addition, the NS3 epitopes used in the recently proposed peptide-based vaccine IC41 were analyzed in the context of our framework. Our analysis predicts that alternative NS3 epitopes may be worth exploring as they might be more efficacious. PMID:24760894

Molecular modeling and residue interaction network studies on the mechanism of binding and resistance of the HCV NS5B polymerase mutants to VX-222 and ANA598.

PubMed

Xue, Weiwei; Jiao, Pingzu; Liu, Huanxiang; Yao, Xiaojun

2014-04-01

Hepatitis C virus (HCV) NS5B protein is an RNA-dependent RNA polymerase (RdRp) with essential functions in viral genome replication and represents a promising therapeutic target to develop direct-acting antivirals (DAAs). Multiple nonnucleoside inhibitors (NNIs) binding sites have been identified within the polymerase. VX-222 and ANA598 are two NNIs targeting thumb II site and palm I site of HCV NS5B polymerase, respectively. These two molecules have been shown to be very effective in phase II clinical trials. However, the emergence of resistant HCV replicon variants (L419M, M423T, I482L mutants to VX-222 and M414T, M414L, G554D mutants to ANA598) has significantly decreased their efficacy. To elucidate the molecular mechanism about how these mutations influenced the drug binding mode and decreased drug efficacy, we studied the binding modes of VX-222 and ANA598 to wild-type and mutant polymerase by molecular modeling approach. Molecular dynamics (MD) simulations results combined with binding free energy calculations indicated that the mutations significantly altered the binding free energy and the interaction for the drugs to polymerase. The further per-residue binding free energy decomposition analysis revealed that the mutations decreased the interactions with several key residues, such as L419, M423, L474, S476, I482, L497, for VX-222 and L384, N411, M414, Y415, Q446, S556, G557 for ANA598. These were the major origins for the resistance to these two drugs. In addition, by analyzing the residue interaction network (RIN) of the complexes between the drugs with wild-type and the mutant polymerase, we found that the mutation residues in the networks involved in the drug resistance possessed a relatively lower size of topology centralities. The shift of betweenness and closeness values of binding site residues in the mutant polymerase is relevant to the mechanism of drug resistance of VX-222 and ANA598. These results can provide an atomic-level understanding about the mechanisms of drug resistance conferred by the studied mutations and will be helpful to design more potent inhibitors which could effectively overcome drug resistance of antivirus agents. Copyright © 2014 Elsevier B.V. All rights reserved.

SCY-635, a Novel Nonimmunosuppressive Analog of Cyclosporine That Exhibits Potent Inhibition of Hepatitis C Virus RNA Replication In Vitro ▿ †

PubMed Central

Hopkins, Sam; Scorneaux, Bernard; Huang, Zhuhui; Murray, Michael G.; Wring, Stephen; Smitley, Craig; Harris, Richard; Erdmann, Frank; Fischer, Gunter; Ribeill, Yves

2010-01-01

SCY-635 is a novel nonimmunosuppressive cyclosporine-based analog that exhibits potent suppression of hepatitis C virus (HCV) replication in vitro. SCY-635 inhibited the peptidyl prolyl isomerase activity of cyclophilin A at nanomolar concentrations but showed no detectable inhibition of calcineurin phosphatase activity at concentrations up to 2 μM. Metabolic studies indicated that SCY-635 did not induce the major cytochrome P450 enzymes 1A2, 2B6, and 3A4. SCY-635 was a weak inhibitor and a poor substrate for P-glycoprotein. Functional assays with stimulated Jurkat cells and stimulated human peripheral blood mononuclear cells indicated that SCY-635 is a weaker inhibitor of interleukin-2 secretion than cyclosporine. A series of two-drug combination studies was performed in vitro. SCY-635 exhibited synergistic antiviral activity with alpha interferon 2b and additive antiviral activity with ribavirin. SCY-635 was shown to be orally bioavailable in multiple animal species and produced blood and liver concentrations of parent drug that exceeded the 50% effective dose determined in the bicistronic con1b-derived replicon assay. These results suggest that SCY-635 warrants further investigation as a novel therapeutic agent for the treatment of individuals who are chronically infected with HCV. PMID:19933795

The resistance mutation R155K in the NS3/4A protease of hepatitis C virus also leads the virus to escape from HLA-A*68-restricted CD8 T cells.

PubMed

Salloum, Shadi; Kluge, Silvia F; Kim, Arthur Y; Roggendorf, Michael; Timm, Joerg

2010-08-01

The NS3/4A serine protease of the hepatitis C virus (HCV) is one of the most attractive targets for specific antiviral agents. However, mutations conferring resistance may decrease the efficacy of these drugs. Although the level of resistance associated with specific mutations differs between different compounds, substitutions R155K and A156T reduce susceptibility to all protease inhibitors published so far. Interestingly, variants harboring the resistant mutation R155K were also detected as the predominant quasispecies in some treatment-naïve patients. Of note, key positions for resistance overlap with the HLA-A*68-restricted epitope HAVGIFRAAV(1175-1184). The aim of our study was to analyze the impact of protease inhibitor resistance mutations on the replication level and the antiviral CD8 T cell response against this HCV epitope. Our findings suggest that the R155K variant is associated with a relatively high replication level and with a substantial loss of cross-recognition by specific CD8 T cells targeting the epitope HAVGIFRAAV(1175-1184), providing a possible explanation for its existence in the absence of drug selection pressure. Copyright 2010 Elsevier B.V. All rights reserved.

[Chronic HCV hepatopathy and cryoglobulinemia. The associated clinical spectrum].

PubMed

Pellicano, R; Leone, N; Maiocco, I A; Modena, V; Arena, V; Marietti, G; Puiatti, P; Palmas, F; Rizzetto, M; Ponzetto, A

1999-01-01

The hepatitis C infection (HCV) has numerous extrahepatic manifestations owing to the systemic nature of the infection itself. HCV infects the cells that carry a CD 81 receptor and show a marked tropism for hepatocytes, bone marrow staminal cells and circulating lymphomonocytes. One consequence of this tropism is the activation of B lymphocyte clones with the consequent production of autoantibodies and cryoglobulins. The secondary event is the formation of circulating immune complexes which, having precipitated at an intravascular level, may cause part of the extrahepatic manifestations associated with these infections. This retrospective study evaluated the manifestations correlated and/or associated with HCV hepatitis and mixed cryoglobulinaemia. This analysis showed that 75% of consecutively studied patients reveal clinically important extrahepatic manifestations. This underlines the "broad spectrum" action played by the hepatitis C virus in the host organism.

Risk factors for prevalent hepatitis C virus-infection among inmates in a state prison system in Mexico

PubMed Central

Mosqueda-Gomez, Juan L.; Macias-Hernandez, Alejando; Sierra-Madero, Juan G.; Ahmed, Saifuddin; Beyrer, Chris

2017-01-01

Objectives To estimate the prevalence of HCV-infection and identify associated factors among inmates in the State Prison System of Guanajuato in Mexico (Sep-2011 to Feb-2012). Methods Cross-sectional, observational study in 10 prisons in the State of Guanajuato in Mexico (2011–2012). We offered HCV-testing and applied audio computer-assisted self-interviews to all adults imprisoned in the State Prison System. We used a complex survey analysis to estimate the distribution of variables and its corresponding 95% confidence intervals, taking into consideration the expected cluster effect by common characteristics within prisons. Inverse probability weights were applied to correct potential biased estimates arising from non-participation in accrual activities and non-response rates. We fitted multivariate logistic regression models to identify risk-behaviors associated to HCV-infection. Results We included data of 2,519 participating inmates. Prevalence of HCV-infection was 4.9 (95%CI = 3.6–5.9). Most HCV-infected inmates were male (99%). Before being incarcerated, inmates with HCV-infection were more frequently tattooed, used and injected drugs more frequently, and were more likely to share materials for injecting, when compared with those non-infected. During incarceration, HCV-infected inmates got tattoos and used drugs more often than non-infected, including injecting-drugs and sharing materials. Injecting-drug use (OR = 7.6, 95%CI, 2.5–23.4), sharing materials for injecting-drugs (OR = 19.6, 95%CI, 4.7–81.7) and being tattooed at least once before incarceration (OR = 2.1, 95%CI, 1.1–3.9), but not during incarceration, were independently associated to HCV-infection. Conclusions The prevalence of HCV-infection among inmates in the State of Guanajuato in Mexico is considerably higher than in the general population. The most important risk factors for HCV in this inmate population were injecting-drugs and sharing materials for injections before incarceration. High-risk behaviors during imprisonment are very high particularly among those already infected. HCV diagnostic and treatment services, and harm-reduction programs for incarcerated injecting-drug users in Mexico should be integrated to control the HCV epidemic in Mexico. PMID:28654650

Risk factors for prevalent hepatitis C virus-infection among inmates in a state prison system in Mexico.

PubMed

Belaunzarán-Zamudio, Pablo F; Mosqueda-Gomez, Juan L; Macias-Hernandez, Alejando; Sierra-Madero, Juan G; Ahmed, Saifuddin; Beyrer, Chris

2017-01-01

To estimate the prevalence of HCV-infection and identify associated factors among inmates in the State Prison System of Guanajuato in Mexico (Sep-2011 to Feb-2012). Cross-sectional, observational study in 10 prisons in the State of Guanajuato in Mexico (2011-2012). We offered HCV-testing and applied audio computer-assisted self-interviews to all adults imprisoned in the State Prison System. We used a complex survey analysis to estimate the distribution of variables and its corresponding 95% confidence intervals, taking into consideration the expected cluster effect by common characteristics within prisons. Inverse probability weights were applied to correct potential biased estimates arising from non-participation in accrual activities and non-response rates. We fitted multivariate logistic regression models to identify risk-behaviors associated to HCV-infection. We included data of 2,519 participating inmates. Prevalence of HCV-infection was 4.9 (95%CI = 3.6-5.9). Most HCV-infected inmates were male (99%). Before being incarcerated, inmates with HCV-infection were more frequently tattooed, used and injected drugs more frequently, and were more likely to share materials for injecting, when compared with those non-infected. During incarceration, HCV-infected inmates got tattoos and used drugs more often than non-infected, including injecting-drugs and sharing materials. Injecting-drug use (OR = 7.6, 95%CI, 2.5-23.4), sharing materials for injecting-drugs (OR = 19.6, 95%CI, 4.7-81.7) and being tattooed at least once before incarceration (OR = 2.1, 95%CI, 1.1-3.9), but not during incarceration, were independently associated to HCV-infection. The prevalence of HCV-infection among inmates in the State of Guanajuato in Mexico is considerably higher than in the general population. The most important risk factors for HCV in this inmate population were injecting-drugs and sharing materials for injections before incarceration. High-risk behaviors during imprisonment are very high particularly among those already infected. HCV diagnostic and treatment services, and harm-reduction programs for incarcerated injecting-drug users in Mexico should be integrated to control the HCV epidemic in Mexico.

Determinants in the Ig Variable Domain of Human HAVCR1 (TIM-1) Are Required To Enhance Hepatitis C Virus Entry.

PubMed

Kachko, Alla; Costafreda, Maria Isabel; Zubkova, Iryna; Jacques, Jerome; Takeda, Kazuyo; Wells, Frances; Kaplan, Gerardo; Major, Marian E

2018-03-15

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis in humans. Several host molecules participate in HCV cell entry, but this process remains unclear. The complete unraveling of the HCV entry process is important to further understand viral pathogenesis and develop therapeutics. Human hepatitis A virus (HAV) cellular receptor 1 (HAVCR1), CD365, also known as TIM-1, functions as a phospholipid receptor involved in cell entry of several enveloped viruses. Here, we studied the role of HAVCR1 in HCV infection. HAVCR1 antibody inhibited entry in a dose-dependent manner. HAVCR1 soluble constructs neutralized HCV, which did not require the HAVCR1 mucinlike region and was abrogated by a mutation of N to A at position 94 (N94A) in the Ig variable (IgV) domain phospholipid-binding pocket, indicating a direct interaction of the HAVCR1 IgV domain with HCV virions. However, knockout of HAVCR1 in Huh7 cells reduced but did not prevent HCV growth. Interestingly, the mouse HAVCR1 ortholog, also a phospholipid receptor, did not enhance infection and a soluble form failed to neutralize HCV, although replacement of the mouse IgV domain with the human HAVCR1 IgV domain restored the enhancement of HCV infection. Mutations in the cytoplasmic tail revealed that direct HAVCR1 signaling is not required to enhance HCV infection. Our data show that the phospholipid-binding function and other determinant(s) in the IgV domain of human HAVCR1 enhance HCV infection. Although the exact mechanism is not known, it is possible that HAVCR1 facilitates entry by stabilizing or enhancing attachment, leading to direct interactions with specific receptors, such as CD81. IMPORTANCE Hepatitis C virus (HCV) enters cells through a multifaceted process. We identified the human hepatitis A virus cellular receptor 1 (HAVCR1), CD365, also known as TIM-1, as a facilitator of HCV entry. Antibody blocking and silencing or knockout of HAVCR1 in hepatoma cells reduced HCV entry. Our findings that the interaction of HAVCR1 with HCV early during infection enhances entry but is not required for infection support the hypothesis that HAVCR1 facilitates entry by stabilizing or enhancing virus binding to the cell surface membrane and allowing the correct virus-receptor positioning for interaction with the main HCV receptors. Furthermore, our data show that in addition to the phospholipid-binding function of HAVCR1, the enhancement of HCV infection involves other determinants in the IgV domain of HAVCR1. These findings expand the repertoire of molecules that HCV uses for cell entry, adding to the already complex mechanism of HCV infection and pathogenesis. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

Prediction of linear B-cell epitopes of hepatitis C virus for vaccine development

PubMed Central

2015-01-01

Background High genetic heterogeneity in the hepatitis C virus (HCV) is the major challenge of the development of an effective vaccine. Existing studies for developing HCV vaccines have mainly focused on T-cell immune response. However, identification of linear B-cell epitopes that can stimulate B-cell response is one of the major tasks of peptide-based vaccine development. Owing to the variability in B-cell epitope length, the prediction of B-cell epitopes is much more complex than that of T-cell epitopes. Furthermore, the motifs of linear B-cell epitopes in different pathogens are quite different (e. g. HCV and hepatitis B virus). To cope with this challenge, this work aims to propose an HCV-customized sequence-based prediction method to identify B-cell epitopes of HCV. Results This work establishes an experimentally verified dataset comprising the B-cell response of HCV dataset consisting of 774 linear B-cell epitopes and 774 non B-cell epitopes from the Immune Epitope Database. An interpretable rule mining system of B-cell epitopes (IRMS-BE) is proposed to select informative physicochemical properties (PCPs) and then extracts several if-then rule-based knowledge for identifying B-cell epitopes. A web server Bcell-HCV was implemented using an SVM with the 34 informative PCPs, which achieved a training accuracy of 79.7% and test accuracy of 70.7% better than the SVM-based methods for identifying B-cell epitopes of HCV and the two general-purpose methods. This work performs advanced analysis of the 34 informative properties, and the results indicate that the most effective property is the alpha-helix structure of epitopes, which influences the connection between host cells and the E2 proteins of HCV. Furthermore, 12 interpretable rules are acquired from top-five PCPs and achieve a sensitivity of 75.6% and specificity of 71.3%. Finally, a conserved promising vaccine candidate, PDREMVLYQE, is identified for inclusion in a vaccine against HCV. Conclusions This work proposes an interpretable rule mining system IRMS-BE for extracting interpretable rules using informative physicochemical properties and a web server Bcell-HCV for predicting linear B-cell epitopes of HCV. IRMS-BE may also apply to predict B-cell epitopes for other viruses, which benefits the improvement of vaccines development of these viruses without significant modification. Bcell-HCV is useful for identifying B-cell epitopes of HCV antigen to help vaccine development, which is available at http://e045.life.nctu.edu.tw/BcellHCV. PMID:26680271

Computational biology approach to uncover hepatitis C virus helicase operation.

PubMed

Flechsig, Holger

2014-04-07

Hepatitis C virus (HCV) helicase is a molecular motor that splits nucleic acid duplex structures during viral replication, therefore representing a promising target for antiviral treatment. Hence, a detailed understanding of the mechanism by which it operates would facilitate the development of efficient drug-assisted therapies aiming to inhibit helicase activity. Despite extensive investigations performed in the past, a thorough understanding of the activity of this important protein was lacking since the underlying internal conformational motions could not be resolved. Here we review investigations that have been previously performed by us for HCV helicase. Using methods of structure-based computational modelling it became possible to follow entire operation cycles of this motor protein in structurally resolved simulations and uncover the mechanism by which it moves along the nucleic acid and accomplishes strand separation. We also discuss observations from that study in the light of recent experimental studies that confirm our findings.

Insulin resistance and liver steatosis in chronic hepatitis C infection genotype 3.

PubMed

Abenavoli, Ludovico; Masarone, Mario; Peta, Valentina; Milic, Natasa; Kobyliak, Nazarii; Rouabhia, Samir; Persico, Marcello

2014-11-07

Hepatitis C virus (HCV) infection is a common chronic liver disease worldwide. Non-alcoholic fatty liver disease and insulin resistance (IR) are the major determinants of fibrosis progression and response to antiviral therapy. The pathogenetic link between IR and chronic HCV infection is complex, and is associated with HCV genotype. Liver steatosis is the most common in the patients infected with genotype 3 virus, possibly due to direct effects of genotype 3 viral proteins. To the contrary, hepatic steatosis in the patients infected with other genotypes is thought to be mostly due to the changes in host metabolism, involving IR. In HCV genotype 3, liver steatosis correlates with viral load, reverts after reaching the sustained virologic response and reoccurs in the relapsers. A therapeutic strategy to improve IR and liver steatosis and subsequently the response to antiviral treatment in these patients is warranted.

[Research Progress on Antiviral Activity of Interferon-induced Transmembrane Proteins].

PubMed

Chen, Yongkun; Zhu, Wenfei; Shu, Yuelong

2016-03-01

Interferon-induced Transmembrane Proteins (IFITMs) were identified through small interference RNA (siRNA) screening method in 1980s. The antiviral properties of the IFITMs were firstly discovered in 1996. Recently, its antiviral effect and mechanism have become a research hotspot. Many studies have shown that IFITM can inhibit the replication of multiple pathogenic viruses, including influenza A virus (IAV), Human Immunodeficiency Virus (HIV-1), hepatitis C virus (HCV), Ebola virus (EBOV), West Nile virus and so on. IFITMs inhibit the replication of virus in the early stage of the viral life cycle, which occurred before the release of viral genomes into the cytosol. Recent studies indicate that IFITM proteins could block viral replication by mediate viral membrane fusion. However, the mechanism is still under investigation. Here we review the discovery and characterization of the IFITM proteins, elucidate their antiviral activities and the potential mechanisms.

Control of temporal activation of hepatitis C virus-induced interferon response by domain 2 of nonstructural protein 5A.

PubMed

Hiet, Marie-Sophie; Bauhofer, Oliver; Zayas, Margarita; Roth, Hanna; Tanaka, Yasuhito; Schirmacher, Peter; Willemsen, Joschka; Grünvogel, Oliver; Bender, Silke; Binder, Marco; Lohmann, Volker; Lotteau, Vincent; Ruggieri, Alessia; Bartenschlager, Ralf

2015-10-01

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a multifunctional protein playing a crucial role in diverse steps of the viral replication cycle and perturbing multiple host cell pathways. We showed previously that removal of a region in domain 2 (D2) of NS5A (mutant NS5A(D2Δ)) is dispensable for viral replication in hepatoma cell lines. By using a mouse model and immune-competent cell systems, we studied the role of D2 in controlling the innate immune response. In vivo replication competence of NS5A(D2Δ) was studied in transgenic mice with human liver xenografts. Results were validated using primary human hepatocytes (PHHs) and mechanistic analyses were conducted in engineered Huh7 hepatoma cells with reconstituted innate signaling pathways. Although the deletion in NS5A removed most of the interferon (IFN) sensitivity determining-region, mutant NS5A(D2Δ) was as sensitive as the wild type to IFN-α and IFN-λ in vitro, but severely attenuated in vivo. This attenuation could be recapitulated in PHHs and was linked to higher activation of the IFN response, concomitant with reduced viral replication and virus production. Importantly, immune-reconstituted Huh7-derived cell lines revealed a sequential activation of the IFN-response via RIG-I (retinoic acid-inducible gene I) and MDA5 (Myeloma differentiation associated factor 5), respectively, that was significantly higher in the case of the mutant lacking most of NS5A D2. Our study reveals an important role of NS5A D2 for suppression of the IFN response that is activated by HCV via RIG-I and MDA5 in a sequential manner. Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Rationale, design, and methodology of a trial evaluating three models of care for HCV treatment among injection drug users on opioid agonist therapy.

PubMed

Akiyama, Matthew J; Agyemang, Linda; Arnsten, Julia H; Heo, Moonseong; Norton, Brianna L; Schackman, Bruce R; Linas, Benjamin P; Litwin, Alain H

2018-02-09

People who inject drugs (PWID) constitute 60% of the approximately 5 million people in the U.S. infected with hepatitis C virus (HCV). Treatment of PWID is complex due to addiction, mental illness, poverty, homelessness, lack of positive social support, poor adherence-related skills, low motivation and knowledge, and poor access to and trust in the health care system. New direct-acting antiviral medications are available for HCV with high cure rates and few side effects. The life expectancy and economic benefits of new HCV treatments will not be realized unless we determine optimal models of care for the majority of HCV-infected patients. The purpose of this study is to evaluate the effectiveness of directly observed therapy and group treatment compared with self-administered individual treatment in a large, urban opioid agonist therapy clinic setting in the Bronx, New York. In this randomized controlled trial 150 PWID with chronic HCV were recruited from opioid agonist treatment (OAT) clinics and randomized to one of three models of onsite HCV treatment in OAT: 1) modified directly observed therapy; 2) group treatment; or 3) control - self-administered individual treatment. Participants were age 18 or older, HCV genotype 1, English or Spanish speaking, treatment naïve (or treatment experienced after 12/3/14), willing to receive HCV treatment onsite, receiving methadone or buprenorphine at the medication window at least once per week, and able to provide informed consent. Outcomes of interest include adherence (as measured by self-report and electronic blister packs), HCV treatment completion, sustained virologic response, drug resistance, and cost-effectiveness. This paper describes the design and rationale of a randomized controlled trial comparing three models of care for HCV therapy delivered in an opioid agonist treatment program. Our trial will be critical to rigorously identify models of care that result in high adherence and cure rates. Use of blister pack technology will help us determine the role of adherence in successful cure of HCV. Moreover, the trial methodology outlined here can serve as a template for the development of future programs and studies among HCV-infected drug users receiving opioid agonist therapy, as well as the cost-effectiveness of such programs. This trial was registered with ClinicalTrials.gov ( NCT01857245 ). Trial registration was obtained prospectively on May 20th, 2013.

On-chip purification and detection of hepatitis C virus RNA from human plasma.

PubMed

Vaghi, V; Potrich, C; Pasquardini, L; Lunelli, L; Vanzetti, L; Ebranati, E; Lai, A; Zehender, G; Mombello, D; Cocuzza, M; Pirri, C F; Pederzolli, C

2016-01-01

Hepatitis C virus (HCV) is one of the main causes of chronic liver disease worldwide. The diagnosis and monitoring of HCV infection is a crucial need in the clinical management. The conventional diagnostic technologies are challenged when trying to address molecular diagnostics, especially because they require a complex and time-consuming sample preparation phase. Here, a new concept based on surface functionalization was applied to viral RNA purification: first of all polydimethylsiloxane (PDMS) flat surfaces were modified to hold RNA adsorption. After a careful chemical and morphological analysis of the modified surfaces, the functionalization protocols giving the best RNA adsorbing surfaces were applied to PDMS microdevices. The functionalized microdevices were then used for RNA purification from HCV infected human plasma samples. RNA purification and RT were successfully performed in the same microdevice chamber, saving time of analysis, reagents, and labor. The PCR protocol for HCV cDNA amplification was also implemented in the microdevice, demonstrating that the entire process of HCV analysis, from plasma to molecular readout, could be performed on-chip. Not only HCV but also other microdevice-based viral RNA detection could therefore result in a successful Point-of-Care (POC) diagnostics for resource-limited settings. Copyright © 2015 Elsevier B.V. All rights reserved.

New Treatments Have Changed the Game: Hepatitis C Treatment in Primary Care.

PubMed

Facente, Shelley N; Burk, Katie; Eagen, Kelly; Mara, Elise S; Smith, Aaron A; Lynch, Colleen S

2018-06-01

In the pre-direct-acting antiviral era, hepatitis C virus (HCV) treatments were complex and largely managed by hepatologists, gastroenterologists, and infectious disease physicians. As direct-acting antivirals have driven up demand for treatment, the relative scarcity of these specialists has created a bottleneck effect, resulting in only a fraction of HCV-infected individuals offered treatment. The San Francisco Health Network is a safety net system of care. Its intervention was designed to be sustainable and scalable; with minimal time commitments for training providers, primary care-based HCV treatment increased 3-fold in a period of just over 3 years. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Dynamics of an HBV/HCV infection model with intracellular delay and cell proliferation

NASA Astrophysics Data System (ADS)

Zhang, Fengqin; Li, Jianquan; Zheng, Chongwu; Wang, Lin

2017-01-01

A new mathematical model of hepatitis B/C virus (HBV/HCV) infection which incorporates the proliferation of healthy hepatocyte cells and the latent period of infected hepatocyte cells is proposed and studied. The dynamics is analyzed via Pontryagin's method and a newly proposed alternative geometric stability switch criterion. Sharp conditions ensuring stability of the infection persistent equilibrium are derived by applying Pontryagin's method. Using the intracellular delay as the bifurcation parameter and applying an alternative geometric stability switch criterion, we show that the HBV/HCV infection model undergoes stability switches. Furthermore, numerical simulations illustrate that the intracellular delay can induce complex dynamics such as persistence bubbles and chaos.

Hepatitis A and hepatitis C viruses: divergent infection outcomes marked by similarities in induction and evasion of interferon responses.

PubMed

Qu, Lin; Lemon, Stanley M

2010-11-01

Hepatitis A and hepatitis C viruses (HAV and HCV) are both positive-strand ribonucleic acid (RNA) viruses with hepatotropic lifestyles. Despite several important differences, they share many biological and molecular features and similar genome replication schemes. Despite this, HAV infections are usually effectively controlled by the host with elimination of the virus, whereas HCV most often is able to establish lifelong persistent infection. The mechanisms underlying this difference are unknown. The cellular helicases RIG-I and MDA5, and Toll-like receptor 3, are pattern recognition receptors that sense virus-derived RNAs within hepatocytes in the liver. Activation of these receptors leads to their interaction with specific adaptor proteins, mitochondrial antiviral signaling protein (MAVS) and TIR-domain-containing adapter-inducing interferon-β (TRIF), respectively, which engage downstream kinases to activate two crucial transcription factors, nuclear factor kappa B (NF-κB) and interferon regulatory factor 3 (IRF3). This results in the induction of interferons (IFNs) and IFN-stimulated genes that ultimately establish an antiviral state. These signaling pathways are central to host antiviral defense and thus frequent targets for viral interference. Both HAV and HCV express proteases that target signal transduction through these pathways and that block the induction of IFNs upon sensing of viral RNA by these receptors. An understanding of the differences and similarities in the early innate immune responses to these infections is likely to provide important insights into the mechanism underlying the long-term persistence of HCV. © Thieme Medical Publishers.

Inactivated ORF virus shows antifibrotic activity and inhibits human hepatitis B virus (HBV) and hepatitis C virus (HCV) replication in preclinical models.

PubMed

Paulsen, Daniela; Urban, Andreas; Knorr, Andreas; Hirth-Dietrich, Claudia; Siegling, Angela; Volk, Hans-Dieter; Mercer, Andrew A; Limmer, Andreas; Schumak, Beatrix; Knolle, Percy; Ruebsamen-Schaeff, Helga; Weber, Olaf

2013-01-01

Inactivated orf virus (iORFV), strain D1701, is a potent immune modulator in various animal species. We recently demonstrated that iORFV induces strong antiviral activity in animal models of acute and chronic viral infections. In addition, we found D1701-mediated antifibrotic effects in different rat models of liver fibrosis. In the present study, we compare iORFV derived from two different strains of ORFV, D1701 and NZ2, respectively, with respect to their antifibrotic potential as well as their potential to induce an antiviral response controlling infections with the hepatotropic pathogens hepatitis C virus (HCV) and hepatitis B virus (HBV). Both strains of ORFV showed anti-viral activity against HCV in vitro and against HBV in a transgenic mouse model without signs of necro-inflammation in vivo. Our experiments suggest that the absence of liver damage is potentially mediated by iORFV-induced downregulation of antigen cross-presentation in liver sinus endothelial cells. Furthermore, both strains showed significant anti-fibrotic activity in rat models of liver fibrosis. iORFV strain NZ2 appeared more potent compared to strain D1701 with respect to both its antiviral and antifibrotic activity on the basis of dosages estimated by titration of active virus. These results show a potential therapeutic approach against two important human liver pathogens HBV and HCV that independently addresses concomitant liver fibrosis. Further studies are required to characterize the details of the mechanisms involved in this novel therapeutic principle.

Targeting Endoplasmic Reticulum and/or Mitochondrial Ca2+ Fluxes as Therapeutic Strategy for HCV Infection.

PubMed

Scrima, Rosella; Piccoli, Claudia; Moradpour, Darius; Capitanio, Nazzareno

2018-01-01

Chronic hepatitis C is characterized by metabolic disorders and by a microenvironment in the liver dominated by oxidative stress, inflammation and regeneration processes that can in the long term lead to liver cirrhosis and hepatocellular carcinoma. Several lines of evidence suggest that mitochondrial dysfunctions play a central role in these processes. However, how these dysfunctions are induced by the virus and whether they play a role in disease progression and neoplastic transformation remains to be determined. Most in vitro studies performed so far have shown that several of the hepatitis C virus (HCV) proteins also localize to mitochondria, but the consequences of these interactions on mitochondrial functions remain contradictory and need to be confirmed in the context of productively replicating virus and physiologically relevant in vitro and in vivo model systems. In the past decade we have been proposing a temporal sequence of events in the HCV-infected cell whereby the primary alteration is localized at the mitochondria-associated ER membranes and causes release of Ca 2+ from the ER, followed by uptake into mitochondria. This ensues successive mitochondrial dysfunction leading to the generation of reactive oxygen and nitrogen species and a progressive metabolic adaptive response consisting in decreased oxidative phosphorylation and enhanced aerobic glycolysis and lipogenesis. Here we resume the major results provided by our group in the context of HCV-mediated alterations of the cellular inter-compartmental calcium flux homeostasis and present new evidence suggesting targeting of ER and/or mitochondrial calcium transporters as a novel therapeutic strategy.

Targeting endoplasmic reticulum and/or mitochondrial Ca2+ fluxes as therapeutic strategy for HCV infection

NASA Astrophysics Data System (ADS)

Scrima, Rosella; Piccoli, Claudia; Moradpour, Darius; Capitanio, Nazzareno

2018-03-01

Chronic hepatitis C is characterized by metabolic disorders and by a microenvironment in the liver dominated by oxidative stress, inflammation and regeneration processes that can in the long term lead to liver cirrhosis and hepatocellular carcinoma. Several lines of evidence suggest that mitochondrial dysfunctions play a central role in these processes. However, how these dysfunctions are induced by the virus and whether they play a role in disease progression and neoplastic transformation remains to be determined. Most in vitro studies performed so far have shown that several of the hepatitis C virus (HCV) proteins also localize to mitochondria, but the consequences of these interactions on mitochondrial functions remain contradictory and need to be confirmed in the context of productively replicating virus and physiologically relevant in vitro and in vivo model systems. In the past decade we have been proposing a temporal sequence of events in the HCV-infected cell whereby the primary alteration is localized at the mitochondria-associated ER membranes and causes release of Ca2+ from the ER, followed by uptake into mitochondria. This ensues successive mitochondrial dysfunction leading to the generation of reactive oxygen and nitrogen species and a progressive metabolic adaptive response consisting in decreased oxidative phosphorylation and enhanced aerobic glycolysis and lipogenesis. Here we resume the major results provided by our group in the context of HCV-mediated alterations of the cellular inter-compartmental calcium flux homeostasis and present new evidence suggesting targeting of ER and/or mitochondrial calcium transporters as a novel therapeutic strategy.

Serum levels of immunoglobulin free light chains in patients with chronic hepatitis C presenting cryoglobulinemia.

PubMed

Oliveira, Isabela S; Cabral, Milena S; Jesus, Larissa S; Paraná, Raymundo; Atta, Ajax M; Sousa Atta, Maria Luiza B

2014-01-01

Hepatitis C virus (HCV) infects B-lymphocytes, provokes cellular dysfunction and causes lymphoproliferative diseases such as cryoglobulinemia and non-Hodgkin's B-cell lymphoma. In the present study, we investigated the serum levels of kappa and lambda free light chains (FLC) of immunoglobulins and the kappa/lambda FLC ratio in Brazilian patients with chronic HCV infection and cryoglobulinemia. We also analyzed the immunochemical composition of the cryoglobulins in these patients. Twenty-eight cryoglobulinemic HCV patients composed the target group, while 37 HCV patients without cryoglobulinemia were included as controls. The median levels of kappa and lambda FLC were higher in patients with cryoglobulinemia compared to controls (p=0.001 and p=0.003, respectively), but the kappa/lambda FLC ratio was similar in patients with and without cryoglobulinemia (p>0.05). The median FLC ratio was higher in HCV patients presenting with advanced fibrosis of the liver compared to HCV patients without fibrosis (p=0.004). Kappa and lambda FLC levels were strongly correlated with the IgA, IgG and IgM levels in the patients with cryoglobulinemia. In patients without cryoglobulinemia, the kappa FLC level was only correlated with the IgG level, whereas the lambda FLC were weakly correlated with the IgA, IgG and IgM levels. An immunochemical pattern of mixed cryoglobulins (MC), predominantly IgM, IgG, IgA and kappa light chain, was verified in these immune complexes. We concluded that HCV-infected patients presenting cryoglobulinemia have vigorous polyclonal B-lymphocyte activation due to chronic HCV infection and persistent immune stimulation. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

Molecular Signature and Mechanisms of Hepatitis D Virus-Associated Hepatocellular Carcinoma.

PubMed

Diaz, Giacomo; Engle, Ronald E; Tice, Ashley; Melis, Marta; Montenegro, Stephanie; Rodriguez-Canales, Jaime; Hanson, Jeffrey; Emmert-Buck, Michael R; Bock, Kevin W; Moore, Ian N; Zamboni, Fausto; Govindarajan, Sugantha; Kleiner, David; Farci, Patrizia

2018-06-01

There is limited data on the molecular mechanisms whereby hepatitis D virus (HDV) promotes liver cancer. Therefore, serum and liver specimens obtained at the time of liver transplantation from well-characterized patients with HDV-HCC (n-5) and with non-HCC HDV cirrhosis (n=7) were studied using an integrated genomic approach. Transcriptomic profiling was performed using laser capture-microdissected (LCM) malignant and non-malignant hepatocytes, tumorous and non-tumorous liver tissue from patients with HDV-HCC, and liver tissue from patients with non-HCC HDV cirrhosis. HDV-HCC was also compared with hepatitis B virus (HBV) HBV-HCC alone and hepatitis C virus (HCV) HCV-HCC. HDV malignant hepatocytes were characterized by an enrichment of up-regulated transcripts associated with pathways involved in cell cycle/DNA replication, damage and repair (sonic hedgehog, GADD45, DNA-damage-induced 14-3-3σ, cyclins and cell cycle regulation, cell cycle: G2/M DNA-damage checkpoint regulation, and hereditary breast cancer). Moreover, a large network of genes identified functionally relate to DNA repair, cell cycle, mitotic apparatus and cell division, including 4 cancer testis antigen genes, attesting to the critical role of genetic instability in this tumor. Besides being over-expressed, these genes were also strongly co-regulated. Gene co-regulation was high not only when compared to non-malignant hepatocytes, but also to malignant hepatocytes from HBV-HCC alone or HCV-HCC. Activation and co-regulation of genes critically associated with DNA replication, damage, and repair point to genetic instability as an important mechanism of HDV hepatocarcinogenesis. This specific HDV-HCC trait emerged also from the comparison of the molecular pathways identified for each hepatitis virus-associated HCC. Despite the dependence of HDV on HBV, these findings suggest that HDV and HBV promote carcinogenesis by distinct molecular mechanisms. This study identifies a molecular signature of HDV-associated hepatocellular carcinoma and suggests the potential for new biomarkers for early diagnostics. Copyright ©2018, American Association for Cancer Research.

RNA chaperoning and intrinsic disorder in the core proteins of Flaviviridae.

PubMed

Ivanyi-Nagy, Roland; Lavergne, Jean-Pierre; Gabus, Caroline; Ficheux, Damien; Darlix, Jean-Luc

2008-02-01

RNA chaperone proteins are essential partners of RNA in living organisms and viruses. They are thought to assist in the correct folding and structural rearrangements of RNA molecules by resolving misfolded RNA species in an ATP-independent manner. RNA chaperoning is probably an entropy-driven process, mediated by the coupled binding and folding of intrinsically disordered protein regions and the kinetically trapped RNA. Previously, we have shown that the core protein of hepatitis C virus (HCV) is a potent RNA chaperone that can drive profound structural modifications of HCV RNA in vitro. We now examined the RNA chaperone activity and the disordered nature of core proteins from different Flaviviridae genera, namely that of HCV, GBV-B (GB virus B), WNV (West Nile virus) and BVDV (bovine viral diarrhoea virus). Despite low-sequence similarities, all four proteins demonstrated general nucleic acid annealing and RNA chaperone activities. Furthermore, heat resistance of core proteins, as well as far-UV circular dichroism spectroscopy suggested that a well-defined 3D protein structure is not necessary for core-induced RNA structural rearrangements. These data provide evidence that RNA chaperoning-possibly mediated by intrinsically disordered protein segments-is conserved in Flaviviridae core proteins. Thus, besides nucleocapsid formation, core proteins may function in RNA structural rearrangements taking place during virus replication.

RNA chaperoning and intrinsic disorder in the core proteins of Flaviviridae

PubMed Central

Ivanyi-Nagy, Roland; Lavergne, Jean-Pierre; Gabus, Caroline; Ficheux, Damien; Darlix, Jean-Luc

2008-01-01

RNA chaperone proteins are essential partners of RNA in living organisms and viruses. They are thought to assist in the correct folding and structural rearrangements of RNA molecules by resolving misfolded RNA species in an ATP-independent manner. RNA chaperoning is probably an entropy-driven process, mediated by the coupled binding and folding of intrinsically disordered protein regions and the kinetically trapped RNA. Previously, we have shown that the core protein of hepatitis C virus (HCV) is a potent RNA chaperone that can drive profound structural modifications of HCV RNA in vitro. We now examined the RNA chaperone activity and the disordered nature of core proteins from different Flaviviridae genera, namely that of HCV, GBV-B (GB virus B), WNV (West Nile virus) and BVDV (bovine viral diarrhoea virus). Despite low-sequence similarities, all four proteins demonstrated general nucleic acid annealing and RNA chaperone activities. Furthermore, heat resistance of core proteins, as well as far-UV circular dichroism spectroscopy suggested that a well-defined 3D protein structure is not necessary for core-induced RNA structural rearrangements. These data provide evidence that RNA chaperoning—possibly mediated by intrinsically disordered protein segments—is conserved in Flaviviridae core proteins. Thus, besides nucleocapsid formation, core proteins may function in RNA structural rearrangements taking place during virus replication. PMID:18033802

Drug-Drug Interactions and Diagnostics for Drug Users With HIV and HIV/HCV Coinfections: Introduction.

PubMed

Khalsa, Jag H; Talal, Andrew H; Morse, Gene

2017-03-01

Substance use and pharmacologic treatment of co-occurring infections such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are associated with many adverse consequences including pharmacokinetic and pharmacodynamic drug-drug interactions (DDIs). The National Institute on Drug Abuse sponsored a 2-day conference on DDIs at which clinicians/scientists from government, academia, and the pharmaceutical industry presented the most current research findings to formulate a comprehensive overview of DDIs. Specific topics discussed included drug metabolism; drug interactions between medications used in the treatment of HIV, HCV, and substance use disorders; intrahepatic concentrations and methods of assessment of drugs in liver disease of varying etiologies and degrees of impairment; and minimally invasive sampling techniques for the assessment of intrahepatic drug concentrations, viral replication, and changes in gene expression in response to treatment. Finally, the speakers identified research targets and priorities on DDIs. Areas of emphasis included development of diagnostic assays for drug concentration assessment in different organs, an enhanced understanding of factors responsible for alterations in drug metabolism and excretion, and establishment of clinical trials and work groups to study DDIs. Our long-term objective is to broaden investigation in the field of DDIs in substance users. © 2017, The American College of Clinical Pharmacology.

Gut epithelial barrier dysfunction in human immunodeficiency virus-hepatitis C virus coinfected patients: Influence on innate and acquired immunity.

PubMed

Márquez, Mercedes; Fernández Gutiérrez del Álamo, Clotilde; Girón-González, José Antonio

2016-01-28

Even in cases where viral replication has been controlled by antiretroviral therapy for long periods of time, human immunodeficiency virus (HIV)-infected patients have several non-acquired immunodeficiency syndrome (AIDS) related co-morbidities, including liver disease, cardiovascular disease and neurocognitive decline, which have a clear impact on survival. It has been considered that persistent innate and acquired immune activation contributes to the pathogenesis of these non-AIDS related diseases. Immune activation has been related with several conditions, remarkably with the bacterial translocation related with the intestinal barrier damage by the HIV or by hepatitis C virus (HCV)-related liver cirrhosis. Consequently, increased morbidity and mortality must be expected in HIV-HCV coinfected patients. Disrupted gut barrier lead to an increased passage of microbial products and to an activation of the mucosal immune system and secretion of inflammatory mediators, which in turn might increase barrier dysfunction. In the present review, the intestinal barrier structure, measures of intestinal barrier dysfunction and the modifications of them in HIV monoinfection and in HIV-HCV coinfection will be considered. Both pathogenesis and the consequences for the progression of liver disease secondary to gut microbial fragment leakage and immune activation will be assessed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rong, Libin; Guedj, Jeremie; Dahari, Harel

The current paradigm for studying hepatitis C virus (HCV) dynamics in patients utilizes a standard viral dynamic model that keeps track of uninfected (target) cells, infected cells, and virus. The model does not account for the dynamics of intracellular viral replication, which is the major target of direct-acting antiviral agents (DAAs). In this paper, we describe and study a recently developed multiscale age-structured model that explicitly considers the potential effects of DAAs on intracellular viral RNA production, degradation, and secretion as virus into the circulation. We show that when therapy significantly blocks both intracellular viral RNA production and virus secretion,more » the serum viral load decline has three phases, with slopes reflecting the rate of serum viral clearance, the rate of loss of intracellular viral RNA, and the rate of loss of intracellular replication templates and infected cells, respectively. We also derive analytical approximations of the multiscale model and use one of them to analyze data from patients treated for 14 days with the HCV protease inhibitor danoprevir. Analysis suggests that danoprevir significantly blocks intracellular viral production (with mean effectiveness 99.2%), enhances intracellular viral RNA degradation about 5-fold, and moderately inhibits viral secretion (with mean effectiveness 56%). Finally, the multiscale model can be used to study viral dynamics in patients treated with other DAAs and explore their mechanisms of action in treatment of hepatitis C.« less

3D-QSAR and molecular docking studies on designing inhibitors of the hepatitis C virus NS5B polymerase

NASA Astrophysics Data System (ADS)

Li, Wenlian; Si, Hongzong; Li, Yang; Ge, Cuizhu; Song, Fucheng; Ma, Xiuting; Duan, Yunbo; Zhai, Honglin

2016-08-01

Viral hepatitis C infection is one of the main causes of the hepatitis after blood transfusion and hepatitis C virus (HCV) infection is a global health threat. The HCV NS5B polymerase, an RNA dependent RNA polymerase (RdRp) and an essential role in the replication of the virus, has no functional equivalent in mammalian cells. So the research and development of efficient NS5B polymerase inhibitors provides a great strategy for antiviral therapy against HCV. A combined three-dimensional quantitative structure-activity relationship (QSAR) modeling was accomplished to profoundly understand the structure-activity correlation of a train of indole-based inhibitors of the HCV NS5B polymerase to against HCV. A comparative molecular similarity indices analysis (COMSIA) model as the foundation of the maximum common substructure alignment was developed. The optimum model exhibited statistically significant results: the cross-validated correlation coefficient q2 was 0.627 and non-cross-validated r2 value was 0.943. In addition, the results of internal validations of bootstrapping and Y-randomization confirmed the rationality and good predictive ability of the model, as well as external validation (the external predictive correlation coefficient rext2 = 0.629). The information obtained from the COMSIA contour maps enables the interpretation of their structure-activity relationship. Furthermore, the molecular docking study of the compounds for 3TYV as the protein target revealed important interactions between active compounds and amino acids, and several new potential inhibitors with higher activity predicted were designed basis on our analyses and supported by the simulation of molecular docking. Meanwhile, the OSIRIS Property Explorer was introduced to help select more satisfactory compounds. The satisfactory results from this study may lay a reliable theoretical base for drug development of hepatitis C virus NS5B polymerase inhibitors.

Hepatitis C Virus in Kidney Transplant Recipients: A Problem on the Path to Eradication.

PubMed

Suarez Benjumea, A; Gonzalez-Corvillo, C; Sousa, J M; Bernal Blanco, G; Suñer Poblet, M; Perez Valdivia, M A; Gonzalez Roncero, F M; Acevedo, P; Gentil Govantez, M A

2016-11-01

Hepatitis C virus (HCV) still has significant prevalence in kidney transplant (KT) recipients and is related to poor recipient and graft survival. New direct-acting antivirals (DAA) are leading to a radical change in the problem. We studied HCV prevalence at the time of transplantation and in follow-up patients, the way cases are handled, and the results of DAA. A total of 2,001 KT had been performed in our center since 1978. Pre- or post-transplantation HCV serology was present in 1,880 cases and was positive in 13.4%. A total of 1,195 transplant recipients were still being monitored by us, with only 60 (5%) HCV+ and 45 (3.6%) RNA+ cases. Of these 45 HCV+/RNA+, 25 had been or were being treated, 7 were about to begin treatment, 1 was awaiting new DAA treatment owing to low glomerular filtration rate (GFR), 3 were being evaluated, 2 had been excluded owing to high comorbidity, 2 refused to be treated, 2 needed to return to hemodialysis, and 1 was lost to follow-up. Except 1 case where Viekira Pak was used because of low GFR, all cases included sofosbuvir as the main drug associated with either ledipasvir (70%) or daclatasvir (25%). Ribavirin was added as coadjuvant in 35% of cases. Twenty-one patients had completed treatment (84%). Two patients had to interrupt DAA therapy (8%), one because of hepatotoxicity and the other as a result of a liver transplantation. In every case, the graft maintained function and negativization of viral replication occurred. Side effects have been low, anemia related to ribavirin being the main one. Just one case needed to be interrupted at the 7th week of DAA therapy due to hepatotoxicity. It has frequently been necessary to adjust immunosuppression treatment with the use of higher doses of tacrolimus. Copyright © 2016 Elsevier Inc. All rights reserved.

Differential In Vitro Effects of Intravenous versus Oral Formulations of Silibinin on the HCV Life Cycle and Inflammation

PubMed Central

Wagoner, Jessica; Morishima, Chihiro; Graf, Tyler N.; Oberlies, Nicholas H.; Teissier, Elodie; Pécheur, Eve-Isabelle; Tavis, John E.; Polyak, Stephen J.

2011-01-01

Silymarin prevents liver disease in many experimental rodent models, and is the most popular botanical medicine consumed by patients with hepatitis C. Silibinin is a major component of silymarin, consisting of the flavonolignans silybin A and silybin B, which are insoluble in aqueous solution. A chemically modified and soluble version of silibinin, SIL, has been shown to potently reduce hepatitis C virus (HCV) RNA levels in vivo when administered intravenously. Silymarin and silibinin inhibit HCV infection in cell culture by targeting multiple steps in the virus lifecycle. We tested the hepatoprotective profiles of SIL and silibinin in assays that measure antiviral and anti-inflammatory functions. Both mixtures inhibited fusion of HCV pseudoparticles (HCVpp) with fluorescent liposomes in a dose-dependent fashion. SIL inhibited 5 clinical genotype 1b isolates of NS5B RNA dependent RNA polymerase (RdRp) activity better than silibinin, with IC50 values of 40–85 µM. The enhanced activity of SIL may have been in part due to inhibition of NS5B binding to RNA templates. However, inhibition of the RdRps by both mixtures plateaued at 43–73%, suggesting that the products are poor overall inhibitors of RdRp. Silibinin did not inhibit HCV replication in subgenomic genotype 1b or 2a replicon cell lines, but it did inhibit JFH-1 infection. In contrast, SIL inhibited 1b but not 2a subgenomic replicons and also inhibited JFH-1 infection. Both mixtures inhibited production of progeny virus particles. Silibinin but not SIL inhibited NF-κB- and IFN-B-dependent transcription in Huh7 cells. However, both mixtures inhibited T cell proliferation to similar degrees. These data underscore the differences and similarities between the intravenous and oral formulations of silibinin, which could influence the clinical effects of this mixture on patients with chronic liver diseases. PMID:21297992

A protein coevolution method uncovers critical features of the Hepatitis C Virus fusion mechanism

PubMed Central

Douam, Florian; Mancip, Jimmy; Mailly, Laurent; Montserret, Roland; Ding, Qiang; Verhoeyen, Els; Baumert, Thomas F.; Ploss, Alexander; Carbone, Alessandra

2018-01-01

Amino-acid coevolution can be referred to mutational compensatory patterns preserving the function of a protein. Viral envelope glycoproteins, which mediate entry of enveloped viruses into their host cells, are shaped by coevolution signals that confer to viruses the plasticity to evade neutralizing antibodies without altering viral entry mechanisms. The functions and structures of the two envelope glycoproteins of the Hepatitis C Virus (HCV), E1 and E2, are poorly described. Especially, how these two proteins mediate the HCV fusion process between the viral and the cell membrane remains elusive. Here, as a proof of concept, we aimed to take advantage of an original coevolution method recently developed to shed light on the HCV fusion mechanism. When first applied to the well-characterized Dengue Virus (DENV) envelope glycoproteins, coevolution analysis was able to predict important structural features and rearrangements of these viral protein complexes. When applied to HCV E1E2, computational coevolution analysis predicted that E1 and E2 refold interdependently during fusion through rearrangements of the E2 Back Layer (BL). Consistently, a soluble BL-derived polypeptide inhibited HCV infection of hepatoma cell lines, primary human hepatocytes and humanized liver mice. We showed that this polypeptide specifically inhibited HCV fusogenic rearrangements, hence supporting the critical role of this domain during HCV fusion. By combining coevolution analysis and in vitro assays, we also uncovered functionally-significant coevolving signals between E1 and E2 BL/Stem regions that govern HCV fusion, demonstrating the accuracy of our coevolution predictions. Altogether, our work shed light on important structural features of the HCV fusion mechanism and contributes to advance our functional understanding of this process. This study also provides an important proof of concept that coevolution can be employed to explore viral protein mediated-processes, and can guide the development of innovative translational strategies against challenging human-tropic viruses. PMID:29505618

Hepatitis C virus infection inhibits P-body granule formation in human livers.

PubMed

Pérez-Vilaró, Gemma; Fernández-Carrillo, Carlos; Mensa, Laura; Miquel, Rosa; Sanjuan, Xavier; Forns, Xavier; Pérez-del-Pulgar, Sofía; Díez, Juana

2015-04-01

Decoding the myriad of interactions that hepatitis C virus (HCV) establishes with infected cells is mandatory to obtain a complete understanding of HCV biology and its associated pathogenesis. We and others have previously found that HCV infection disrupts the formation of P-bodies in cell culture. These are cytoplasmic RNA granules with key roles in post-transcriptional regulation of gene expression. Therefore, P-body disruption might have consequences beyond viral propagation. However, whether P-body disruption occurs also in vivo is unknown. Aim of this study was to address this important issue. Formalin-fixed paraffin-embedded liver biopsies from four groups of patients (healthy donors, patients with non-virus related liver inflammation, HCV- and HBV-infected patients) were immunostained to detect DDX6 and Dcp1, two core P-body components. Changes in the localization of these proteins were assessed by confocal microscopy. HCV specifically inhibited P-body formation in hepatocytes from human livers regardless of viral genotype, inflammation grade or whether the infection was recent or long established. Importantly, this alteration was reversed once HCV was eliminated by therapy. Furthermore, we observed in vivo an unexpected heterogeneity in P-body composition, which might reflect functional specializations. This is the first comprehensive in vivo P-body analysis that links a pathogenic condition to P-body alterations. Because of their role in gene expression, the alteration of P-bodies should be further studied to understand fully complex HCV-associated pathologies. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

[Research advances in the role of sphingolipids in HCV and HBV life cycles].

PubMed

Zhang, J Y; Duan, Z P; Zhang, J L; Zheng, S J

2016-12-20

Sphingolipids and their metabolites are not only important structural molecules of the cell membrane, but also involved in all phases of viral life cycle, including cell adhesion, membrane fusion, viral replication, viral assembly, intracellular transport, protein sorting, and exocytosis. In recent years, sphingolipids have become one of the focuses of lipid research. This article reviews the role of sphingolipids in the life cycles of hepatitis C virus and hepatitis B virus with reference to recent research achievements in China and foreign countries.

Characterization of Hepatitis C Virus Core Protein Multimerization and Membrane Envelopment: Revelation of a Cascade of Core-Membrane Interactions ▿

PubMed Central

Ai, Li-Shuang; Lee, Yu-Wen; Chen, Steve S.-L.

2009-01-01

The molecular basis underlying hepatitis C virus (HCV) core protein maturation and morphogenesis remains elusive. We characterized the concerted events associated with core protein multimerization and interaction with membranes. Analyses of core proteins expressed from a subgenomic system showed that the signal sequence located between the core and envelope glycoprotein E1 is critical for core association with endoplasmic reticula (ER)/late endosomes and the core's envelopment by membranes, which was judged by the core's acquisition of resistance to proteinase K digestion. Despite exerting an inhibitory effect on the core's association with membranes, (Z-LL)2-ketone, a specific inhibitor of signal peptide peptidase (SPP), did not affect core multimeric complex formation, suggesting that oligomeric core complex formation proceeds prior to or upon core attachment to membranes. Protease-resistant core complexes that contained both innate and processed proteins were detected in the presence of (Z-LL)2-ketone, implying that core envelopment occurs after intramembrane cleavage. Mutations of the core that prevent signal peptide cleavage or coexpression with an SPP loss-of-function D219A mutant decreased the core's envelopment, demonstrating that SPP-mediated cleavage is required for core envelopment. Analyses of core mutants with a deletion in domain I revealed that this domain contains sequences crucial for core envelopment. The core proteins expressed by infectious JFH1 and Jc1 RNAs in Huh7 cells also assembled into a multimeric complex, associated with ER/late-endosomal membranes, and were enveloped by membranes. Treatment with (Z-LL)2-ketone or coexpression with D219A mutant SPP interfered with both core envelopment and infectious HCV production, indicating a critical role of core envelopment in HCV morphogenesis. The results provide mechanistic insights into the sequential and coordinated processes during the association of the HCV core protein with membranes in the early phase of virus maturation and morphogenesis. PMID:19605478

Decreasing racial disparity with the combination of ledipasvir-sofosbuvir for the treatment of chronic hepatitis C.

PubMed

Naylor, Paul H; Mutchnick, Milton

2017-01-01

African Americans (AA) in the US are twice as likely to be infected with hepatitis C virus (HCV) compared to the non-Hispanic-white US population (Cau). They are also more likely to be infected with HCV genotype 1, more likely to develop hepatocellular carcinoma, and, in addition, have a lower response rate to interferon-based therapies. With the increase in response rates reported for combinations of direct-acting antivirals, the possibility that racial disparity would be eliminated by agents that directly inhibit virus replication has become a reality. The objective of this review is to evaluate the literature from clinical studies and retrospective analysis with respect to the response of AA to the most prescribed antiviral combination sofosbuvir plus ledipasvir. While few studies have focused on AA patients, sufficient information is availed from the literature and studies in our predominately AA clinic population to confirm that ledipasvir-sofosbuvir has a similar effectiveness in AA as compared to Cau.

Coordination of Hepatitis C Virus Assembly by Distinct Regulatory Regions in Nonstructural Protein 5A

PubMed Central

Zayas, Margarita; Long, Gang; Madan, Vanesa; Bartenschlager, Ralf

2016-01-01

Hepatitis C virus (HCV) nonstructural protein (NS)5A is a RNA-binding protein composed of a N-terminal membrane anchor, a structured domain I (DI) and two intrinsically disordered domains (DII and DIII) interacting with viral and cellular proteins. While DI and DII are essential for RNA replication, DIII is required for assembly. How these processes are orchestrated by NS5A is poorly understood. In this study, we identified a highly conserved basic cluster (BC) at the N-terminus of DIII that is critical for particle assembly. We generated BC mutants and compared them with mutants that are blocked at different stages of the assembly process: a NS5A serine cluster (SC) mutant blocked in NS5A-core interaction and a mutant lacking the envelope glycoproteins (ΔE1E2). We found that BC mutations did not affect core-NS5A interaction, but strongly impaired core–RNA association as well as virus particle envelopment. Moreover, BC mutations impaired RNA-NS5A interaction arguing that the BC might be required for loading of core protein with viral RNA. Interestingly, RNA-core interaction was also reduced with the ΔE1E2 mutant, suggesting that nucleocapsid formation and envelopment are coupled. These findings argue for two NS5A DIII determinants regulating assembly at distinct, but closely linked steps: (i) SC-dependent recruitment of replication complexes to core protein and (ii) BC-dependent RNA genome delivery to core protein, triggering encapsidation that is tightly coupled to particle envelopment. These results provide a striking example how a single viral protein exerts multiple functions to coordinate the steps from RNA replication to the assembly of infectious virus particles. PMID:26727512

Inhibition of Bovine Viral Diarrhea Virus RNA Synthesis by Thiosemicarbazone Derived from 5,6-Dimethoxy-1-Indanone▿

PubMed Central

Castro, Eliana F.; Fabian, Lucas E.; Caputto, María E.; Gagey, Dolores; Finkielsztein, Liliana M.; Moltrasio, Graciela Y.; Moglioni, Albertina G.; Campos, Rodolfo H.; Cavallaro, Lucía V.

2011-01-01

In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV). PMID:21430053

Inhibition of bovine viral diarrhea virus RNA synthesis by thiosemicarbazone derived from 5,6-dimethoxy-1-indanone.

PubMed

Castro, Eliana F; Fabian, Lucas E; Caputto, María E; Gagey, Dolores; Finkielsztein, Liliana M; Moltrasio, Graciela Y; Moglioni, Albertina G; Campos, Rodolfo H; Cavallaro, Lucía V

2011-06-01

In the present work, we described the activity of the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone (TSC), which we previously characterized as a new compound that inhibits bovine viral diarrhea virus (BVDV) infection. We showed that TSC acts at a point of time that coincides with the onset of viral RNA synthesis and that it inhibits the activity of BVDV replication complexes (RCs). Moreover, we have selected five BVDV mutants that turned out to be highly resistant to TSC but still susceptible to ribavirin (RBV). Four of these resistant mutants carried an N264D mutation in the viral RNA-dependent RNA polymerase (RdRp). The remaining mutant showed an A392E mutation within the same protein. Some of these mutants replicated slower than the wild-type (wt) virus in the absence of TSC, whereas others showed a partial reversion to the wt phenotype over several passages in the absence of the compound. The docking of TSC in the crystal structure of the BVDV RdRp revealed a close contact between the indane ring of the compound and several residues within the fingers domain of the enzyme, some hydrophobic contacts, and hydrogen bonds with the thiosemicarbazone group. Finally, in the mutated RdRp from resistant BVDV, these interactions with TSC could not be achieved. Interestingly, TSC inhibited BVDV replication in cell culture synergistically with RBV. In conclusion, TSC emerges as a new nonnucleoside inhibitor of BVDV RdRp that is synergistic with RBV, a feature that turns it into a potential compound to be evaluated against hepatitis C virus (HCV).

Short Communication: Interferon/Ribavirin Treatment for HCV Is Associated with the Development of Hypophosphatemia in HIV/Hepatitis C Virus-Coinfected Patients

PubMed Central

Funk, Emily K.; Shaffer, Ashton; Shivakumar, Bhavana; Sneller, Michael; Polis, Michael A.; Masur, Henry; Heytens, Laura; Nelson, Amy; Kwan, Richard; Kottilil, Shyam

2013-01-01

Abstract One-third of all HIV-infected individuals in the United States are estimated to be coinfected with the hepatitis C virus (HCV). Treatment of chronic hepatitis C in patients coinfected with HIV is a complex problem associated with toxicities and drug interactions between HIV antiretrovirals and interferon and ribavirin. In recent HCV treatment studies, we observed a previously unreported development of hypophosphatemia in HIV/HCV-coinfected patients treated with interferon/ribavirin (IFN/RBV). To further investigate this observation, we retrospectively reviewed 61 HIV/HCV-coinfected patients on antiretrovirals (ARVs) during treatment with IFN/RBV as well as 154 HIV-infected patients treated with ARVs alone. We found that HIV/HCV-coinfected patients on IFN/RBV therapy were more likely to develop frequent (57% vs. 13%, IFN/RBV-treated patients vs. no IFN/RBV; χ2=0.001) and higher-grade hypophosphatemia (67.0% Grade 2, 33.3% Grade 3 vs. 94.7% Grade 2, 5.3% Grade 3, IFN/RBV-treated patients vs. no IFN/RBV; χ2<0.001) than untreated patients. In addition, we found that the new onset of hypophosphatemia after IFN/RBV treatment initiation was followed by a diminished frequency of this toxicity upon cessation of IFN/RBV, supporting the idea that a drug–drug interaction may increase the risk of this toxicity. To understand the risks of developing this toxicity, we evaluated the association between individual ARV use and hypophosphatemia incidence. Our data suggest that concomitant tenofovir (TDF) use may be a risk factor for the development of hypophosphatemia in HIV/HCV-coinfected patients treated with IFN/RBV. Although the etiology of this abnormality is likely multifactorial, clinicians should be aware of hypophosphatemia as a potential marker of renal toxicity in HIV/HCV-coinfected patients being treated with IFN/RBV regimens. PMID:23701022

Short communication: Interferon/ribavirin treatment for HCV is associated with the development of hypophosphatemia in HIV/hepatitis C virus-coinfected patients.

PubMed

Funk, Emily K; Shaffer, Ashton; Shivakumar, Bhavana; Sneller, Michael; Polis, Michael A; Masur, Henry; Heytens, Laura; Nelson, Amy; Kwan, Richard; Kottilil, Shyam; Kohli, Anita

2013-09-01

One-third of all HIV-infected individuals in the United States are estimated to be coinfected with the hepatitis C virus (HCV). Treatment of chronic hepatitis C in patients coinfected with HIV is a complex problem associated with toxicities and drug interactions between HIV antiretrovirals and interferon and ribavirin. In recent HCV treatment studies, we observed a previously unreported development of hypophosphatemia in HIV/HCV-coinfected patients treated with interferon/ribavirin (IFN/RBV). To further investigate this observation, we retrospectively reviewed 61 HIV/HCV-coinfected patients on antiretrovirals (ARVs) during treatment with IFN/RBV as well as 154 HIV-infected patients treated with ARVs alone. We found that HIV/HCV-coinfected patients on IFN/RBV therapy were more likely to develop frequent (57% vs. 13%, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)=0.001) and higher-grade hypophosphatemia (67.0% Grade 2, 33.3% Grade 3 vs. 94.7% Grade 2, 5.3% Grade 3, IFN/RBV-treated patients vs. no IFN/RBV; χ(2)<0.001) than untreated patients. In addition, we found that the new onset of hypophosphatemia after IFN/RBV treatment initiation was followed by a diminished frequency of this toxicity upon cessation of IFN/RBV, supporting the idea that a drug-drug interaction may increase the risk of this toxicity. To understand the risks of developing this toxicity, we evaluated the association between individual ARV use and hypophosphatemia incidence. Our data suggest that concomitant tenofovir (TDF) use may be a risk factor for the development of hypophosphatemia in HIV/HCV-coinfected patients treated with IFN/RBV. Although the etiology of this abnormality is likely multifactorial, clinicians should be aware of hypophosphatemia as a potential marker of renal toxicity in HIV/HCV-coinfected patients being treated with IFN/RBV regimens.

Bacteriophage T7 RNA polymerase-based expression in Pichia pastoris.

PubMed

Hobl, Birgit; Hock, Björn; Schneck, Sandra; Fischer, Reinhard; Mack, Matthias

2013-11-01

A novel Pichia pastoris expression vector (pEZT7) for the production of recombinant proteins employing prokaryotic bacteriophage T7 RNA polymerase (T7 RNAP) (EC 2.7.7.6) and the corresponding promoter pT7 was constructed. The gene for T7 RNAP was stably introduced into the P. pastoris chromosome 2 under control of the (endogenous) constitutive P. pastoris glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter (pGAP). The gene product T7 RNAP was engineered to contain a nuclear localization signal, which directed recombinant T7 RNAP to the P. pastoris nucleus. To promote translation of uncapped T7 RNAP derived transcripts, the internal ribosomal entry site from hepatitis C virus (HCV-IRES) was inserted directly upstream of the multiple cloning site of pEZT7. A P. pastoris autonomous replicating sequence (PARS1) was integrated into pEZT7 enabling propagation and recovery of plasmids from P. pastoris. Rapid amplification of 5' complementary DNA ends (5' RACE) experiments employing the test plasmid pEZT7-EGFP revealed that transcripts indeed initiated at pT7. HCV-IRES mediated translation of the latter mRNAs, however, was not observed. Surprisingly, HCV-IRES and the reverse complement of PARS1 (PARS1rc) were both found to display significant promoter activity as shown by 5' RACE. Copyright © 2013 Elsevier Inc. All rights reserved.

Association between chronic viral hepatitis infection and breast cancer risk: a nationwide population-based case-control study

PubMed Central

2011-01-01

Background In Taiwan, there is a high incidence of breast cancer and a high prevalence of viral hepatitis. In this case-control study, we used a population-based insurance dataset to evaluate whether breast cancer in women is associated with chronic viral hepatitis infection. Methods From the claims data, we identified 1,958 patients with newly diagnosed breast cancer during the period 2000-2008. A randomly selected, age-matched cohort of 7,832 subjects without cancer was selected for comparison. Multivariable logistic regression models were constructed to calculate odds ratios of breast cancer associated with viral hepatitis after adjustment for age, residential area, occupation, urbanization, and income. The age-specific (<50 years and ≥50 years) risk of breast cancer was also evaluated. Results There were no significant differences in the prevalence of hepatitis C virus (HCV) infection, hepatitis B virus (HBV), or the prevalence of combined HBC/HBV infection between breast cancer patients and control subjects (p = 0.48). Multivariable logistic regression analysis, however, revealed that age <50 years was associated with a 2-fold greater risk of developing breast cancer (OR = 2.03, 95% CI = 1.23-3.34). Conclusions HCV infection, but not HBV infection, appears to be associated with early onset risk of breast cancer in areas endemic for HCV and HBV. This finding needs to be replicated in further studies. PMID:22115285

Minimal dose interferon suppository treatment suppresses viral replication with platelet counts and serum albumin levels increased in chronically hepatitis C virus-infected patients: a phase 1b, placebo-controlled, randomized study.

PubMed

Haruna, Yoshimichi; Inoue, Atsuo

2014-02-01

Animal studies have shown that rectally administrated interferon (IFN) is transferred into the lymphatic system via the rectal mucous membrane, suggesting that an IFN suppository could serve as another drug delivery method. We developed an IFN suppository and administered it to patients with chronic hepatitis C to evaluate its efficacy and safety. Twenty-eight patients with chronic hepatitis C participated in the study. The low-dose IFN suppository containing 1,000 international units (IU) of lymphoblastoid IFNα was administered to 14 patients daily for 24 weeks. Others had a placebo dosing. In 13 of the 14 IFN suppository-treated patients, viral load decreased at week 4. The serum hepatitis C virus (HCV) RNA levels (Log IU/mL, mean±standard error) were 5.65±0.18 before the treatment and 5.17±0.27 at week 4 (P=0.01). The 2'-5' oligoadenylate synthetase activity increased, while the CD4/CD8 ratio decreased significantly. Interestingly, platelet counts and serum albumin levels were significantly increased during and after the treatment. No serious adverse events were observed. The low-dose IFN suppository treatment suppressed HCV replication, modifying host immunity, with increased platelet counts and serum albumin levels. The IFN suppository could be considered a new drug delivery method to preserve the quality of life of patients.

Analysis of Hepatitis C Virus Decline during Treatment with the Protease Inhibitor Danoprevir Using a Multiscale Model

DOE PAGES

Rong, Libin; Guedj, Jeremie; Dahari, Harel; ...

2013-03-14

The current paradigm for studying hepatitis C virus (HCV) dynamics in patients utilizes a standard viral dynamic model that keeps track of uninfected (target) cells, infected cells, and virus. The model does not account for the dynamics of intracellular viral replication, which is the major target of direct-acting antiviral agents (DAAs). In this paper, we describe and study a recently developed multiscale age-structured model that explicitly considers the potential effects of DAAs on intracellular viral RNA production, degradation, and secretion as virus into the circulation. We show that when therapy significantly blocks both intracellular viral RNA production and virus secretion,more » the serum viral load decline has three phases, with slopes reflecting the rate of serum viral clearance, the rate of loss of intracellular viral RNA, and the rate of loss of intracellular replication templates and infected cells, respectively. We also derive analytical approximations of the multiscale model and use one of them to analyze data from patients treated for 14 days with the HCV protease inhibitor danoprevir. Analysis suggests that danoprevir significantly blocks intracellular viral production (with mean effectiveness 99.2%), enhances intracellular viral RNA degradation about 5-fold, and moderately inhibits viral secretion (with mean effectiveness 56%). Finally, the multiscale model can be used to study viral dynamics in patients treated with other DAAs and explore their mechanisms of action in treatment of hepatitis C.« less

Resistance analysis and characterization of NITD008 as an adenosine analog inhibitor against hepatitis C virus.

PubMed

Qing, Jie; Luo, Rui; Wang, Yaxin; Nong, Junxiu; Wu, Ming; Shao, Yan; Tang, Ruoyi; Yu, Xi; Yin, Zheng; Sun, Yuna

2016-02-01

Hepatitis disease caused by hepatitis C virus (HCV) is a severe threat to global public health, affecting approximately 3% of the world's population. Sofosbuvir (PSI-7977), a uridine nucleotide analog inhibitor targeting the HCV NS5B polymerase, was approved by FDA at the end of 2013 and represents a key step towards a new era in the management of HCV infection. Previous study identified NITD008, an adenosine nucleoside analog, as the specific inhibitor against dengue virus and showed good antiviral effect on other flaviviruses or enteroviruses. In this report, we systematically analyzed the anti-HCV profile of NITD008, which was discovered to effectively suppress the replication of different strains of HCV in human hepatoma cells with a low nanomolar activity. On genotype 2a virus, or 2a, 1a, and 1b replicon cells, EC50 values were 8.7 nM, 93.3 nM, 60.0 nM and 67.2 nM, and selective index values were >2298.9, >214.4, >333.3, >298.5 respectively. We demonstrated that resistance to NITD008 was conferred by mutation in NS5B (S282T) in the HCV infectious virus genotype 2a (JFH-1). Then, we compared the resistant profiles of NITD008 and PSI-7977, and found that the folds change of EC50 of NITD008 to full replicon cells containing mutation S282T was much bigger than PSI-7977(folds 76.50 vs. 4.52). Analysis of NITD008 cross-resistance against previously reported NS5B drug-selected mutations showed that the resistance pattern of NITD008 was not completely similar to PSI-7977, and meanwhile, S282T resistant mutation to NITD008 emerge more easily in cell culture than PSI-7977. Interestingly, NITD008 displayed significant synergistic effects with the NS5B polymerase inhibitor PSI-7977, however, only additive effects with alpha interferon (IFNα-2b), ribavirin, and an NS3 protease inhibitor. These results verify that NITD008 is an effective analog inhibitor against hepatitis C virus and a good research tool as a supplement to other types of nucleoside analogs. Copyright © 2015 Elsevier B.V. All rights reserved.

Production of infectious chimeric hepatitis C virus genotype 2b harboring minimal regions of JFH-1.

PubMed

Murayama, Asako; Kato, Takanobu; Akazawa, Daisuke; Sugiyama, Nao; Date, Tomoko; Masaki, Takahiro; Nakamoto, Shingo; Tanaka, Yasuhito; Mizokami, Masashi; Yokosuka, Osamu; Nomoto, Akio; Wakita, Takaji

2012-02-01

To establish a cell culture system for chimeric hepatitis C virus (HCV) genotype 2b, we prepared a chimeric construct harboring the 5' untranslated region (UTR) to the E2 region of the MA strain (genotype 2b) and the region of p7 to the 3' UTR of the JFH-1 strain (genotype 2a). This chimeric RNA (MA/JFH-1.1) replicated and produced infectious virus in Huh7.5.1 cells. Replacement of the 5' UTR of this chimera with that from JFH-1 (MA/JFH-1.2) enhanced virus production, but infectivity remained low. In a long-term follow-up study, we identified a cell culture-adaptive mutation in the core region (R167G) and found that it enhanced virus assembly. We previously reported that the NS3 helicase (N3H) and the region of NS5B to 3' X (N5BX) of JFH-1 enabled replication of the J6CF strain (genotype 2a), which could not replicate in cells. To reduce JFH-1 content in MA/JFH-1.2, we produced a chimeric viral genome for MA harboring the N3H and N5BX regions of JFH-1, combined with a JFH-1 5' UTR replacement and the R167G mutation (MA/N3H+N5BX-JFH1/R167G). This chimeric RNA replicated efficiently, but virus production was low. After the introduction of four additional cell culture-adaptive mutations, MA/N3H+N5BX-JFH1/5am produced infectious virus efficiently. Using this chimeric virus harboring minimal regions of JFH-1, we analyzed interferon sensitivity and found that this chimeric virus was more sensitive to interferon than JFH-1 and another chimeric virus containing more regions from JFH-1 (MA/JFH-1.2/R167G). In conclusion, we established an HCV genotype 2b cell culture system using a chimeric genome harboring minimal regions of JFH-1. This cell culture system may be useful for characterizing genotype 2b viruses and developing antiviral strategies.

Identification and functional analysis of a core gene module associated with hepatitis C virus-induced human hepatocellular carcinoma progression.

PubMed

Bai, Gaobo; Zheng, Wenling; Ma, Wenli

2018-05-01

Hepatitis C virus (HCV)-induced human hepatocellular carcinoma (HCC) progression may be due to a complex multi-step processes. The developmental mechanism of these processes is worth investigating for the prevention, diagnosis and therapy of HCC. The aim of the present study was to investigate the molecular mechanism underlying the progression of HCV-induced hepatocarcinogenesis. First, the dynamic gene module, consisting of key genes associated with progression between the normal stage and HCC, was identified using the Weighted Gene Co-expression Network Analysis tool from R language. By defining those genes in the module as seeds, the change of co-expression in differentially expressed gene sets in two consecutive stages of pathological progression was examined. Finally, interaction pairs of HCV viral proteins and their directly targeted proteins in the identified module were extracted from the literature and a comprehensive interaction dataset from yeast two-hybrid experiments. By combining the interactions between HCV and their targets, and protein-protein interactions in the Search Tool for the Retrieval of Interacting Genes database (STRING), the HCV-key genes interaction network was constructed and visualized using Cytoscape software 3.2. As a result, a module containing 44 key genes was identified to be associated with HCC progression, due to the dynamic features and functions of those genes in the module. Several important differentially co-expressed gene pairs were identified between non-HCC and HCC stages. In the key genes, cyclin dependent kinase 1 (CDK1), NDC80, cyclin A2 (CCNA2) and rac GTPase activating protein 1 (RACGAP1) were shown to be targeted by the HCV nonstructural proteins NS5A, NS3 and NS5B, respectively. The four genes perform an intermediary role between the HCV viral proteins and the dysfunctional module in the HCV key genes interaction network. These findings provided valuable information for understanding the mechanism of HCV-induced HCC progression and for seeking drug targets for the therapy and prevention of HCC.

Hepatitis C Virus NS3/4A Protease Inhibitors: A Light at the End of the Tunnel

PubMed Central

Chatel-Chaix, Laurent; Baril, Martin; Lamarre, Daniel

2010-01-01

Hepatitis C virus (HCV) infection is a serious and growing threat to human health. The current treatment provides limited efficacy and is poorly tolerated, highlighting the urgent medical need for novel therapeutics. The membrane-targeted NS3 protein in complex with the NS4A comprises a serine protease domain (NS3/4A protease) that is essential for viral polyprotein maturation and contributes to the evasion of the host innate antiviral immunity by HCV. Therefore, the NS3/4A protease represents an attractive target for drug discovery, which is tied in with the challenge to develop selective small-molecule inhibitors. A rational drug design approach, based on the discovery of N-terminus product inhibition, led to the identification of potent and orally bioavailable NS3 inhibitors that target the highly conserved protease active site. This review summarizes the NS3 protease inhibitors currently challenged in clinical trials as one of the most promising antiviral drug class, and possibly among the first anti-HCV agents to be approved for the treatment of HCV infection. PMID:21994705

Novel dengue virus NS2B/NS3 protease inhibitors.

PubMed

Wu, Hongmei; Bock, Stefanie; Snitko, Mariya; Berger, Thilo; Weidner, Thomas; Holloway, Steven; Kanitz, Manuel; Diederich, Wibke E; Steuber, Holger; Walter, Christof; Hofmann, Daniela; Weißbrich, Benedikt; Spannaus, Ralf; Acosta, Eliana G; Bartenschlager, Ralf; Engels, Bernd; Schirmeister, Tanja; Bodem, Jochen

2015-02-01

Dengue fever is a severe, widespread, and neglected disease with more than 2 million diagnosed infections per year. The dengue virus NS2B/NS3 protease (PR) represents a prime target for rational drug design. At the moment, there are no clinical PR inhibitors (PIs) available. We have identified diaryl (thio)ethers as candidates for a novel class of PIs. Here, we report the selective and noncompetitive inhibition of the serotype 2 and 3 dengue virus PR in vitro and in cells by benzothiazole derivatives exhibiting 50% inhibitory concentrations (IC50s) in the low-micromolar range. Inhibition of replication of DENV serotypes 1 to 3 was specific, since all substances influenced neither hepatitis C virus (HCV) nor HIV-1 replication. Molecular docking suggests binding at a specific allosteric binding site. In addition to the in vitro assays, a cell-based PR assay was developed to test these substances in a replication-independent way. The new compounds inhibited the DENV PR with IC50s in the low-micromolar or submicromolar range in cells. Furthermore, these novel PIs inhibit viral replication at submicromolar concentrations. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Hepatitis C virus testing perspectives among primary care physicians in four large primary care settings.

PubMed

Jewett, Amy; Garg, Arika; Meyer, Katherine; Wagner, Laura Danielle; Krauskopf, Katherine; Brown, Kimberly A; Pan, Jen-Jung; Massoud, Omar; Smith, Bryce D; Rein, David B

2015-03-01

In 1998, the Centers for Disease Control and Prevention (CDC) published Recommendations for Prevention and Control of Hepatitis C Virus (HCV) Infection and HCV-Related Chronic Disease, recommending HCV testing for populations most likely to be infected with HCV. However, the implementation of risk-based screening has not been widely adopted in health care settings, and 45% to 85% of infected U.S. adults remain unidentified. To develop a better understanding of why CDC's 1998 recommendations have had limited success in identifying persons with HCV infection and provide information about how CDC's 2012 Recommendations for the Identification of Chronic Hepatitis C Virus Infection Among Persons Born During 1945-1965 may be implemented more effectively. Qualitative data were collected and analyzed from a multidisciplinary team as part of the Birth Cohort Evaluation to Advance Screening and Testing for Hepatitis C project. Nineteen providers were asked open-ended questions to identify current perspectives, practices, facilitators, and barriers to HCV screening and testing. Providers were affiliated with Henry Ford Hospital, Mount Sinai Hospital, the University of Alabama, and the University of Texas Health Science Center. Respondents reported the complexity of the 1998 recommendations, and numerous indicated risk factors were major barriers to effective implementation. Other hindrances to hepatitis C testing included physician discomfort in asking questions about socially undesirable behaviors and physician uncertainty about patient insurance coverage. Implementation of the CDC's 2012 recommendations could be more successful than the 1998 recommendations due to their relative simplicity; however, effective strategies need to be used for dissemination and implementation for full success. © 2014 Society for Public Health Education.

Bridging basic science and clinical research: the EASL Monothematic Conference on Translational Research in Viral Hepatitis.

PubMed

Boettler, Tobias; Moradpour, Darius; Thimme, Robert; Zoulim, Fabien

2014-09-01

The EASL Monothematic Conference on Translational Research in Viral Hepatitis brought together a group of leading scientists and clinicians working on both, basic and clinical aspects of viral hepatitis, thereby building bridges from bench to bedside. This report recapitulates the presentations and discussions at the conference held in Lyon, France on November 29-30, 2013. In recent years, great advances have been made in the field of viral hepatitis, particularly in hepatitis C virus (HCV) infection. The identification of IL28B genetic polymorphisms as a major determinant for spontaneous and treatment-induced HCV clearance was a seminal discovery. Currently, hepatologists are at the doorstep of even greater advances, with the advent of a wealth of directly acting antivirals (DAAs) against HCV. Indeed, promising results have accumulated over the last months and few years, showing sustained virological response (SVR) rates of up to 100% with interferon-free DAA combination therapies. Thus, less than 25 years after its identification, HCV infection may soon be curable in the vast majority of patients, highlighting the great success of HCV research over the last decades. However, viral hepatitis and its clinical complications such as liver cirrhosis and hepatocellular carcinoma (HCC) remain major global challenges. New therapeutic strategies to tackle hepatitis B virus (HBV) and hepatitis D virus (HDV) infection are needed, as current therapies have undeniable limitations. Nucleoside/nucleotide analogues (NUC) can efficiently control HBV replication and reduce or even reverse liver damage. However, these drugs have to be given for indefinite periods in most patients to maintain virological and biochemical responses. Although sustained responses off treatment can be achieved by treatment with (pegylated) interferon-α, only about 10-30% of patients effectively resolve chronic hepatitis B. It was the goal of this conference to review the progress made over the last years in chronic viral hepatitis research and to identify key questions that need to be addressed in order to close the gap between basic and clinical research and to develop novel preventive and treatment approaches for this most common cause of liver cirrhosis and HCC. Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Agent-Based Model Forecasts Aging of the Population of People Who Inject Drugs in Metropolitan Chicago and Changing Prevalence of Hepatitis C Infections.

PubMed

Gutfraind, Alexander; Boodram, Basmattee; Prachand, Nikhil; Hailegiorgis, Atesmachew; Dahari, Harel; Major, Marian E

2015-01-01

People who inject drugs (PWID) are at high risk for blood-borne pathogens transmitted during the sharing of contaminated injection equipment, particularly hepatitis C virus (HCV). HCV prevalence is influenced by a complex interplay of drug-use behaviors, social networks, and geography, as well as the availability of interventions, such as needle exchange programs. To adequately address this complexity in HCV epidemic forecasting, we have developed a computational model, the Agent-based Pathogen Kinetics model (APK). APK simulates the PWID population in metropolitan Chicago, including the social interactions that result in HCV infection. We used multiple empirical data sources on Chicago PWID to build a spatial distribution of an in silico PWID population and modeled networks among the PWID by considering the geography of the city and its suburbs. APK was validated against 2012 empirical data (the latest available) and shown to agree with network and epidemiological surveys to within 1%. For the period 2010-2020, APK forecasts a decline in HCV prevalence of 0.8% per year from 44(± 2)% to 36(± 5)%, although some sub-populations would continue to have relatively high prevalence, including Non-Hispanic Blacks, 48(± 5)%. The rate of decline will be lowest in Non-Hispanic Whites and we find, in a reversal of historical trends, that incidence among non-Hispanic Whites would exceed incidence among Non-Hispanic Blacks (0.66 per 100 per years vs 0.17 per 100 person years). APK also forecasts an increase in PWID mean age from 35(± 1) to 40(± 2) with a corresponding increase from 59(± 2)% to 80(± 6)% in the proportion of the population >30 years old. Our studies highlight the importance of analyzing subpopulations in disease predictions, the utility of computer simulation for analyzing demographic and health trends among PWID and serve as a tool for guiding intervention and prevention strategies in Chicago, and other major cities.

Cyclophilin B facilitates the replication of Orf virus.

PubMed

Zhao, Kui; Li, Jida; He, Wenqi; Song, Deguang; Zhang, Ximu; Zhang, Di; Zhou, Yanlong; Gao, Feng

2017-06-15

Viruses interact with host cellular factors to construct a more favourable environment for their efficient replication. Expression of cyclophilin B (CypB), a cellular peptidyl-prolyl cis-trans isomerase (PPIase), was found to be significantly up-regulated. Recently, a number of studies have shown that CypB is important in the replication of several viruses, including Japanese encephalitis virus (JEV), hepatitis C virus (HCV) and human papillomavirus type 16 (HPV 16). However, the function of cellular CypB in ORFV replication has not yet been explored. Suppression subtractive hybridization (SSH) technique was applied to identify genes differentially expressed in the ORFV-infected MDBK cells at an early phase of infection. Cellular CypB was confirmed to be significantly up-regulated by quantitative reverse transcription-PCR (qRT-PCR) analysis and Western blotting. The role of CypB in ORFV infection was further determined using Cyclosporin A (CsA) and RNA interference (RNAi). Effect of CypB gene silencing on ORFV replication by 50% tissue culture infectious dose (TCID 50 ) assay and qRT-PCR detection. In the present study, CypB was found to be significantly up-regulated in the ORFV-infected MDBK cells at an early phase of infection. Cyclosporin A (CsA) exhibited suppressive effects on ORFV replication through the inhibition of CypB. Silencing of CypB gene inhibited the replication of ORFV in MDBK cells. In conclusion, these data suggest that CypB is critical for the efficient replication of the ORFV genome. Cellular CypB was confirmed to be significantly up-regulated in the ORFV-infected MDBK cells at an early phase of infection, which could effectively facilitate the replication of ORFV.

A Library of Infectious Hepatitis C Viruses with Engineered Mutations in the E2 Gene Reveals Growth-Adaptive Mutations That Modulate Interactions with Scavenger Receptor Class B Type I.

PubMed

Zuiani, Adam; Chen, Kevin; Schwarz, Megan C; White, James P; Luca, Vincent C; Fremont, Daved H; Wang, David; Evans, Matthew J; Diamond, Michael S

2016-12-01

While natural hepatitis C virus (HCV) infection results in highly diverse quasispecies of related viruses over time, mutations accumulate more slowly in tissue culture, in part because of the inefficiency of replication in cells. To create a highly diverse population of HCV particles in cell culture and identify novel growth-enhancing mutations, we engineered a library of infectious HCV with all codons represented at most positions in the ectodomain of the E2 gene. We identified many putative growth-adaptive mutations and selected nine highly represented E2 mutants for further study: Q412R, T416R, S449P, T563V, A579R, L619T, V626S, K632T, and L644I. We evaluated these mutants for changes in particle-to-infectious-unit ratio, sensitivity to neutralizing antibody or CD81 large extracellular loop (CD81-LEL) inhibition, entry factor usage, and buoyant density profiles. Q412R, T416R, S449P, T563V, and L619T were neutralized more efficiently by anti-E2 antibodies and T416R, T563V, and L619T by CD81-LEL. Remarkably, all nine variants showed reduced dependence on scavenger receptor class B type I (SR-BI) for infection. This shift from SR-BI usage did not correlate with a change in the buoyant density profiles of the variants, suggesting an altered E2-SR-BI interaction rather than changes in the virus-associated lipoprotein-E2 interaction. Our results demonstrate that residues influencing SR-BI usage are distributed across E2 and support the development of large-scale mutagenesis studies to identify viral variants with unique functional properties. Characterizing variant viruses can reveal new information about the life cycle of HCV and the roles played by different viral genes. However, it is difficult to recapitulate high levels of diversity in the laboratory because of limitations in the HCV culture system. To overcome this limitation, we engineered a library of mutations into the E2 gene in the context of an infectious clone of the virus. We used this library of viruses to identify nine mutations that enhance the growth rate of HCV. These growth-enhancing mutations reduced the dependence on a key entry receptor, SR-BI. By generating a highly diverse library of infectious HCV, we mapped regions of the E2 protein that influence a key virus-host interaction and provide proof of principle for the generation of large-scale mutant libraries for the study of pathogens with great sequence variability. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

HCV viraemia in anti-HCV-negative haemodialysis patients: Do we need HCV RNA detection test?

PubMed

Papadopoulos, Nikolaos; Griveas, Ioannis; Sveroni, Eirini; Argiana, Vasiliki; Kalliaropoulos, Antonios; Martinez-Gonzalez, Beatriz; Deutsch, Melanie

2018-03-01

Hepatitis C virus (HCV) infection is still common among dialysis patients, but the natural history of HCV in this group is not completely understood. The KDIGO HCV guidelines of 2009 recommend that chronic haemodialysis patients be screened for HCV antibody upon admission to the dialysis clinic and every 6 months thereafter if susceptible to HCV infection. However, previous studies have shown the presence of HCV viraemia in anti-HCV-negative haemodialysis patients as up to 22%. To evaluate the presence of HCV viraemia, using HCV RNA detection, among anti-HCV-negative haemodialysis patients from a tertiary dialysis unit in Athens. We enrolled 41 anti-HCV-negative haemodialysis patients diagnosed with third-generation enzyme immunoassay. HCV viraemia was evaluated using a sensitive (cut-off: 12 IU/mL) reverse transcriptase polymerase chain reaction (COBAS AmpliPrep/TaqMan system) for HCV RNA. None of the 41 anti-HCV-negative haemodialysis patients were shown to be viraemic. Routine HCV RNA testing appears not to be necessary in anti-HCV-negative haemodialysis patients.

Apolipoprotein B-associated cholesterol is a determinant of treatment outcome in patients with chronic hepatitis C virus infection receiving anti-viral agents interferon-alpha and ribavirin.

PubMed

Sheridan, D A; Price, D A; Schmid, M L; Toms, G L; Donaldson, P; Neely, D; Bassendine, M F

2009-06-15

Hepatitis C virus (HCV) co-opts very-low-density lipoprotein (VLDL) pathways for replication, secretion and entry into hepatocytes and associates with apolipoprotein B (apoB) in plasma. Each VLDL contains apoB-100 and variable amounts of apolipoproteins E and C, cholesterol and triglycerides. To determine whether baseline lipid levels predicted treatment outcome. Retrospective analysis was performed of 250 chronic hepatitis C (CHC) patients who had received anti-viral agents interferon-alpha and ribavirin; 165 had a sustained virological response (SVR). Pre- and post-treatment nonfasting lipid profiles were measured and non-high-density lipoprotein (non-HDL) cholesterol (i.e. apoB-associated) was calculated. Binary logistic regression analysis assessed factors independently associated with treatment outcome. There was an independent association between higher apoB-associated cholesterol (non-HDL-C) and increased odds of SVR (odds ratio 2.09, P = 0.042). In multivariate analysis, non-HDL-C was significantly lower in HCV genotype 3 (g3) than genotype 1 (P = 0.007); this was reversible upon eradication of HCVg3 (pre-treatment non-HDL-C = 2.8 mmol/L, SVR = 3.6 mmol/L, P < 0.001). Higher apoB-associated cholesterol is positively associated with treatment outcome in CHC patients receiving anti-viral therapy, possibly due to competition between apoB-containing lipoproteins and infectious low-density HCV lipo-viral particles for hepatocyte entry via shared lipoprotein receptors.

Exposure to previous cART is associated with significant liver fibrosis and cirrhosis in human immunodeficiency virus-infected patients.

PubMed

Anadol, Evrim; Lust, Kristina; Boesecke, Christoph; Schwarze-Zander, Carolynne; Mohr, Raphael; Wasmuth, Jan-Christian; Rockstroh, Jürgen Kurt; Trebicka, Jonel

2018-01-01

Combined antiretroviral therapy (cART) has improved survival in HIV-patients. While the first antiretrovirals, which became available in particular D-drugs (especially didanosine and stavudine) and unboosted protease inhibitors, may impair liver function, the modern cART seems to decrease liver fibrosis. This study assessed the influence of exposure to previous antiretrovirals on liver fibrosis in HIV-infected patients. This observational cross-sectional single-center study recruited 333 HIV patients and assessed liver fibrosis using transient elastography (TE). 83% were male with a median age of 45, while 131 were co-infected with viral hepatitis. Overall, 18% had significant fibrosis and 7.5% had cirrhosis. 11% of HIV mono-infected patients had significant fibrosis and 2% had cirrhosis. HCV infection (OR:5.3), history of exposure to didanosine (OR:2.7) and HIV load below 40copies/mL (OR:0.5) were independently associated with significant fibrosis, while HCV (OR:5.8), exposure to didanosine (OR:2.9) and azidothymidine (OR:2.8) were independently associated with cirrhosis. Interestingly, in HIV mono-infected patients, a HIV-load below 40copies/mL (OR:0.4) was independently associated with significant fibrosis, and didanosine (OR:20.8) with cirrhosis. In conclusion, history of exposure to didanosine and azidothymidine continues to have an impact on the presence of liver cirrhosis in HIV patients. However, HCV co-infection and ongoing HIV-replication have the strongest effect on development of significant fibrosis in these patients.

Inhibitor candidates's identification of HCV's RNA polymerase NS5B using virtual screening against iPPI-library

NASA Astrophysics Data System (ADS)

Sulistyawati, Indah; Sulistyo Dwi K., P.; Ichsan, Mochammad

2016-03-01

Hepatitis C is one of the major causes of chronic liver failure that caused by Hepatitis C Virus (HCV). Preventing the progression of HCV's replication through the inhibition of The RNA polymerase NS5B of Hepatitis C virus (NS5B) can be achieved via 4 binding regions: Site I (Thumb I), Site II (Thumb II), Site III (Palm I), and Site IV (Palm II). The aim of this research is to identify a candidate of NS5B inhibitor as an alternative for Hepatitis C treatment. An NS5B's 3D structure (PDB ID = 3D5M) used in this study has met some criteria of a good model to be used in virtual screening againts iPPI-lib using MTiOpenScreen webserver. The top two natural compounds resulted here then docked using Pyrix 0.8 and discovered trans-6-Benzamido-2-methyldecahydroisoquinoline (-9,1kcal/mol) and 2,4-dichloro-5-[4-(2 methoxyphenyl) piperazine-1-carbonyl]-N-[3-(trifluoromethyl)phenyl] benzenesulfonamide (9,4 kcal/mol) can bind to Tyr448 similar with all three established inhibitors, such as setrobuvir (-11,4 kcal/mol; site 3 inhibitor), CHEMBL379677 (-9,1 kcal/mol; site 1 inhibitor), and nesbuvir (-7,7 kcal/mol; site 4 inhibitor). The results of this study are relatively still needs to be tested, both in vitro and in vivo, in order to obtain more comprehensive knowledges as a follow-up of this predictive study.

Project HELP: a study protocol to pilot test a shared decision-making tool about treatment options for patients with hepatitis C and chronic kidney disease.

PubMed

Politi, M C; George, N; Li, T; Korenblat, K M; Fowler, K J; Ho, C; Liapakis, A; Roth, D; Yee, J

2018-01-01

Recent advances in treatment have given patients with chronic kidney disease (CKD) access to safer and more effective medications to treat comorbid hepatitis C virus (HCV) infection. Given the variety and complexity of treatment options that depend on patients' clinical characteristics and personal preferences, education and decision support are needed to prepare patients better to discuss treatment options with their clinicians. Drawing on International Patient Decision Aids Standards guidelines, literature reviews, and guidance from a diverse expert advisory group of nephrologists, hepatologists, and patients, we will develop and test a HCV and CKD decision support tool. Named Project HELP ( Helping Empower Liver and kidney Patients ), this tool will support patients with HCV and CKD during decisions about whether, when, and how to treat each illness. The tool will (1) explain information using plain language and graphics; (2) provide a step-by-step process for thinking about treating HCV and CKD; (3) tailor relevant information to each user by asking about the individual's stage of CKD, stage of fibrosis, prior treatment, and comorbidities; (4) assess user knowledge and values for treatment choices; and (5) help individuals use and consider information appropriate to their values and needs to discuss with a clinician. A pilot study including 70 individuals will evaluate the tool's efficacy, usability, and likelihood of using it in clinical practice. Eligibility criteria will include individuals who understand and read English, who are at least 18 years old, have a diagnosis of HCV (any genotype) and CKD (any stage), and are considering treatment options. This study can identify particular characteristics of individuals or groups that might experience challenges initiating treatment for HCV in the CKD population. This tool could provide a resource to facilitate patient-clinician discussions regarding HCV and CKD treatment options.

All-oral daclatasvir plus asunaprevir for hepatitis C virus genotype 1b: a multinational, phase 3, multicohort study.

PubMed

Manns, Michael; Pol, Stanislas; Jacobson, Ira M; Marcellin, Patrick; Gordon, Stuart C; Peng, Cheng-Yuan; Chang, Ting-Tsung; Everson, Gregory T; Heo, Jeong; Gerken, Guido; Yoffe, Boris; Towner, William J; Bourliere, Marc; Metivier, Sophie; Chu, Chi-Jen; Sievert, William; Bronowicki, Jean-Pierre; Thabut, Dominique; Lee, Youn-Jae; Kao, Jia-Horng; McPhee, Fiona; Kopit, Justin; Mendez, Patricia; Linaberry, Misti; Hughes, Eric; Noviello, Stephanie

2014-11-01

An unmet need exists for interferon-free and ribavirin-free treatments for chronic hepatitis C virus (HCV) infection. In this study, we assessed all-oral therapy with daclatasvir (NS5A replication complex inhibitor) plus asunaprevir (NS3 protease inhibitor) in patients with genotype 1b infection, including those with high unmet needs or cirrhosis, or both. We did this phase 3, multicohort study (HALLMARK-DUAL) at 116 sites in 18 countries between May 11, 2012, and Oct 9, 2013. Patients were adults with chronic HCV genotype 1b infection who were treatment-naive; previous non-responders to peginterferon alfa plus ribavirin; or medically ineligible for, previously intolerant of, or ineligible for and intolerant of peginterferon alfa plus ribavirin. Treatment-naive patients were randomly assigned (2:1 ratio) by an interactive voice-response system with a computer-generated random allocation sequence (stratified by cirrhosis status) to receive daclatasvir 60 mg once daily plus asunaprevir 100 mg twice daily or placebo for 12 weeks. Patients and investigator sites were masked to treatment assignment and HCV RNA results to the end of week 12. The treatment-naive group assigned to daclatasvir plus asunaprevir continued open-label treatment to the end of week 24; participants assigned to placebo entered another daclatasvir plus asunaprevir study. Non-responders and ineligible, intolerant, or ineligible and intolerant patients received open-label daclatasvir plus asunaprevir for 24 weeks. The primary endpoint was sustained virological response at post-treatment week 12. Efficacy analyses were restricted to patients given daclatasvir plus asunaprevir. This trial is registered with ClinicalTrials.gov, number NCT01581203. This study included 307 treatment-naive patients (205 received daclatasvir plus asunaprevir and 102 received placebo; all randomly assigned patients received the intended treatment), 205 non-responders, and 235 ineligible, intolerant, or ineligible and intolerant patients. Daclatasvir plus asunaprevir provided sustained virological response in 182 (90%, 95% CI 85-94) patients in the treatment-naive cohort, 168 (82%, 77-87) in the non-responder cohort, and 192 (82%, 77-87) in the ineligible, intolerant, or ineligible and intolerant cohort. Serious adverse events occurred in 12 (6%) patients in the treatment-naive group; 11 (5%) non-responders, and 16 (7%) ineligible, intolerant, or ineligible and intolerant patients; adverse events leading to discontinuation (most commonly reversible increases in alanine or aspartate aminotransferase) occurred in six (3%), two (1%), and two (1%) patients, respectively, with no deaths recorded. Grade 3 or 4 laboratory abnormalities were uncommon, with low incidences of aminotransferase increases during the first 12 weeks with daclatasvir plus asunaprevir and placebo in treatment-naive patients (≤2% each). Daclatasvir plus asunaprevir provided high sustained virological response rates in treatment-naive, non-responder, and ineligible, intolerant, or ineligible and intolerant patients, and was well tolerated in patients with HCV genotype 1b infection. These results support the use of daclatasvir plus asunaprevir as an all-oral, interferon-free and ribavirin-free treatment option for patients with HCV genotype 1b infection, including those with cirrhosis. Bristol-Myers Squibb. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evolution and Persistence of the Resistance-Associated Substitutions of Hepatitis C Virus after Direct-Acting Antiviral Treatment Failures.

PubMed

Jeong, Yechan; Jin, Bora; Lee, Hye Won; Park, Hye Jung; Park, Jun Yong; Kim, Do Young; Han, Kwang-Hyub; Ahn, Sang Hoon; Kim, Seungtaek

2018-05-16

Daclatasvir plus asunaprevir (DCV+ASV) treatment is an all-oral direct-acting antiviral (DAA) therapy for the genotype 1b HCV-infected patients. In this study, we investigated how resistance-associated substitutions (RASs) evolved after treatment failures and assessed the effect of those substitutions on viral fitness. Sequencing of NS5A and NS3 revealed typical RASs after treatment failures. Interestingly, the RASs of NS3 reverted to the wild-type amino acid within one year after treatment failures. However, the RASs of NS5A were stable and did not change. The effect of NS5A and NS3 RASs on viral RNA replication was assessed after mutagenic substitution in the genotype 1b HCV RNA. Among the single substitutions, the effect of D168V was more substantial than the others and the effect of the triple mutant combination (D168V+L31V+Y93H) was the most severe. The RAS at NS5A Y93 affected both viral RNA replication and virus production. Finally, the effect of trans-complementation of NS5A was demonstrated in our co-transfection experiments and these results suggest that such a trans-complementation effect of NS5A may help maintain the NS5A RASs for a long time even after cessation of the DAA treatment. In conclusion, the results from this investigation would help understand the emergence and persistence of RASs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Small molecules targeting viral RNA.

PubMed

Hermann, Thomas

2016-11-01

Highly conserved noncoding RNA (ncRNA) elements in viral genomes and transcripts offer new opportunities to expand the repertoire of drug targets for the development of antiinfective therapy. Ligands binding to ncRNA architectures are able to affect interactions, structural stability or conformational changes and thereby block processes essential for viral replication. Proof of concept for targeting functional RNA by small molecule inhibitors has been demonstrated for multiple viruses with RNA genomes. Strategies to identify antiviral compounds as inhibitors of ncRNA are increasingly emphasizing consideration of drug-like properties of candidate molecules emerging from screening and ligand design. Recent efforts of antiviral lead discovery for RNA targets have provided drug-like small molecules that inhibit viral replication and include inhibitors of human immunodeficiency virus (HIV), hepatitis C virus (HCV), severe respiratory syndrome coronavirus (SARS CoV), and influenza A virus. While target selectivity remains a challenge for the discovery of useful RNA-binding compounds, a better understanding is emerging of properties that define RNA targets amenable for inhibition by small molecule ligands. Insight from successful approaches of targeting viral ncRNA in HIV, HCV, SARS CoV, and influenza A will provide a basis for the future exploration of RNA targets for therapeutic intervention in other viral pathogens which create urgent, unmet medical needs. Viruses for which targeting ncRNA components in the genome or transcripts may be promising include insect-borne flaviviruses (Dengue, Zika, and West Nile) and filoviruses (Ebola and Marburg). WIREs RNA 2016, 7:726-743. doi: 10.1002/wrna.1373 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

Performance of ARCHITECT HCV core antigen test with specimens from US plasma donors and injecting drug users.

PubMed

Mixson-Hayden, Tonya; Dawson, George J; Teshale, Eyasu; Le, Thao; Cheng, Kevin; Drobeniuc, Jan; Ward, John; Kamili, Saleem

2015-05-01

Hepatitis C virus (HCV) core antigen is a serological marker of current HCV infection. The aim of this study was mainly to evaluate the performance characteristics of the ARCHITECT HCV core antigen assay with specimens from US plasma donors and injecting drug users. A total of 551 serum and plasma samples with known anti-HCV and HCV RNA status were tested for HCV core antigen using the Abbott ARCHITECT HCV core antigen test. HCV core antigen was detectable in 100% of US plasma donor samples collected during the pre-seroconversion phase of infection (anti-HCV negative/HCV RNA positive). Overall sensitivity of the HCV core antigen assay was 88.9-94.3% in samples collected after seroconversion. The correlation between HCV core antigen and HCV RNA titers was 0.959. HCV core antigen testing may be reliably used to identify current HCV infection. Published by Elsevier B.V.

Comparison of HCV viral load and its genotype distributions in HCV mono- and HIV/HCV co-infected illicit drug users.

PubMed

Jamalidoust, Marzieh; Namayandeh, Mandana; Moghadami, Mohsen; Ziyaeyan, Mazyar

2017-07-11

Because of shared modes of transmission, patients with hepatitis C virus (HCV) infection are often co-infected with other types of hepatitis viruses and/or HIV. We studied HCV viral load and its genotype patterns among HCV mono- and HCV/HIV co-infected Illicit Drug Users in Fars province-Iran. Totally, 580 HCV seropositive IDUs referred to Prof. Alborzi Clinical Microbiology Research Center, Shiraz, Iran, without receiving any anti-HCV treatment, were enrolled. After their HCV infections were reconfirmed by one step rapid diagnostic test, HCV RNA level and HCV genotypes were determined by Taq-man real-time PCR assays. Their HIV serostatus was determined and seropositive patients were excluded from the group. In addition, 104 HIV/HCV co-infected IDUs referred from Shiraz Behavioral Diseases Consultation Center (SBDC) were assessed for HCV RNA level and HCV genotype patterns, as well. The overall estimated HIV prevalence was 6.7% (39/580) among HCV seropositive IDUs. Genotype 1, the most prevalent genotype in both groups, was detected in 69% and 49% of co- and mono-infected IDUs, respectively. Median HCV viral load was significantly higher in HIV/HCV co-infected patients, compared with that among HCV mono-infected counterparts. Given the higher baseline HCV viral load and GT1 attributed to poorer treatments response, HCV treatment must be more considered among HCV/HIV co-infected IDUs, compared to those mono-infected with HCV.

Discovery and preclinical development of dasabuvir for the treatment of hepatitis C infection.

PubMed

El Kassas, Mohamed; Elbaz, Tamer; Hafez, Enas; Wifi, Mohamed Naguib; Esmat, Gamal

2017-06-01

Hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality. Positively, the introduction of new directly-acting antivirals (DAAs) have led to dramatic improvements in response rates to antiviral therapy. Furthermore, newer generations of DAAs have demonstrated better safety profiles as well as efficacy than older generations. Current treatment recommendations are based on different combinations of DAAs. Current combination therapies rely on agents that target the different steps of viral replication by using different molecules from various DAAs families. Areas covered: In this review, the authors summarize data from of one of the recently developed NS5B polymerase inhibitors, dasabuvir, formerly known as ABT-333. Herein, the authors discuss the drug discovery data for dasabuvir including data from preclinical, toxicological resistance studies. The authors also review dasabuvir's clinical efficacy across various clinical challenges, in addition to its limitations in clinical practice. Expert opinion: Dasabuvir represents an important medical advance when used as a combination therapy for HCV. Unfortunately, it does present limitations like low genotypic coverage and further research is still required to address some of the lingering issues.

Adenovirus vectors lacking virus-associated RNA expression enhance shRNA activity to suppress hepatitis C virus replication

NASA Astrophysics Data System (ADS)

Pei, Zheng; Shi, Guoli; Kondo, Saki; Ito, Masahiko; Maekawa, Aya; Suzuki, Mariko; Saito, Izumu; Suzuki, Tetsuro; Kanegae, Yumi

2013-12-01

First-generation adenovirus vectors (FG AdVs) expressing short-hairpin RNA (shRNA) effectively downregulate the expressions of target genes. However, this vector, in fact, expresses not only the transgene product, but also virus-associated RNAs (VA RNAs) that disturb cellular RNAi machinery. We have established a production method for VA-deleted AdVs lacking expression of VA RNAs. Here, we showed that the highest shRNA activity was obtained when the shRNA was inserted not at the popularly used E1 site, but at the E4 site. We then compared the activities of shRNAs against hepatitis C virus (HCV) expressed from VA-deleted AdVs or conventional AdVs. The VA-deleted AdVs inhibited HCV production much more efficiently. Therefore, VA-deleted AdVs were more effective than the currently used AdVs for shRNA downregulation, probably because of the lack of competition between VA RNAs and the shRNAs. These VA-deleted AdVs might enable more effective gene therapies for chronic hepatitis C.

SYNTHESIS AND ANTIVIRAL EVALUATION OF 9-(S)-[3-ALKOXY-2-(PHOSPHONOMETHOXY)PROPYL]NUCLEOSIDE ALKOXYALKYL ESTERS: INHIBITORS OF HEPATITIS C VIRUS AND HIV-1 REPLICATION

PubMed Central

Valiaeva, Nadejda; Wyles, David L.; Schooley, Robert T.; Hwu, Julia B.; Beadle, James R.; Prichard, Mark N.

2011-01-01

We reported previously that octadecyloxyethyl 9-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]adenine (ODE-(S)-HPMPA) was active against genotype 1b and 2a hepatitis C virus (HCV) replicons. This is surprising because acyclic nucleoside phosphonates have been regarded as having antiviral activity only against double stranded DNA viruses, HIV and HBV. We synthesized octadecyloxyethyl 9-(S)-[3-methoxy-2-(phosphonomethoxy)propyl]-adenine and found it to be active in genotype 1b and 2a HCV replicons with EC50 values of 1-2 μM and a CC50 of>150 μM. Analogs with substitutions at the 3′-hydroxyl larger than methyl or ethyl, or with other purine bases were less active but most compounds had significant antiviral activity against HIV-1 in vitro. The most active anti-HIV compound was octadecyloxyethyl 9-(R)-[3-methoxy-2-(phosphonomethoxy)propyl]guanine with an EC50 <0.01 nanomolar and a selectivity index of>4.4 million. PMID:21719300

Is HCV core antigen a reliable marker of viral load? An evaluation of HCV core antigen automated immunoassay

PubMed Central

Hadziyannis, Emilia; Minopetrou, Martha; Georgiou, Anastasia; Spanou, Fotini; Koskinas, John

2013-01-01

Background Hepatitis C viral (HCV) load detection and quantification is routinely accomplished by HCV RNA measurement, an expensive but essential test, both for the diagnosis and treatment of chronic hepatitis C (CHC). HCV core antigen (Ag) testing has been suggested as an attractive alternative to molecular diagnostics. The aim of the study was to evaluate an automated chemiluminescent immunoassay (CLIA) for HCV core Ag measurement in comparison to quantitative HCV RNA determination. Methods HCV Ag was measured in 105 anti-HCV positive patients, from which 89 were HCV RNA positive with CHC and 16 HCV RNA negative after spontaneous HCV clearance. Viral load was quantified with branched DNA (bDNA, Versant, Siemens). Sera were stored at -70°C and then tested with the Architect HCV Ag test (Abbott Laboratories), a two-step CLIA assay, with high throughput and minimal handling of the specimens. Statistical analysis was performed on logarithmically transformed values. Results HCV-Ag was detectable and quantifiable in 83/89 and in grey zone in 4/89 HCV RNA positive sera. HCV-Ag was undetectable in all 16 HCV RNA negative samples. The sample with the lowest viral load that tested positive for HCV-Ag contained 1200 IU/mL HCV RNA. There was a positive correlation between HCV RNA and HCV-Ag (r=0.89). The HCV RNA/ HCV Ag ratio varied from 1.5 to 3.25. Conclusion The HCV core Ag is an easy test with comparable sensitivity (>90%) and satisfactory correlation with the HCV RNA bDNA assay. Its role in diagnostics and other clinical applications has to be determined based on cost effectiveness. PMID:24714621

The Cobas AmpliPrep/Cobas TaqMan HCV test, version 2.0, real-time PCR assay accurately quantifies hepatitis C virus genotype 4 RNA.

PubMed

Chevaliez, Stéphane; Bouvier-Alias, Magali; Rodriguez, Christophe; Soulier, Alexandre; Poveda, Jean-Dominique; Pawlotsky, Jean-Michel

2013-04-01

Accurate hepatitis C virus (HCV) RNA quantification is mandatory for the management of chronic hepatitis C therapy. The first-generation Cobas AmpliPrep/Cobas TaqMan HCV test (CAP/CTM HCV) underestimated HCV RNA levels by >1-log10 international units/ml in a number of patients infected with HCV genotype 4 and occasionally failed to detect it. The aim of this study was to evaluate the ability of the Cobas AmpliPrep/Cobas TaqMan HCV test, version 2.0 (CAP/CTM HCV v2.0), to accurately quantify HCV RNA in a large series of patients infected with different subtypes of HCV genotype 4. Group A comprised 122 patients with chronic HCV genotype 4 infection, and group B comprised 4 patients with HCV genotype 4 in whom HCV RNA was undetectable using the CAP/CTM HCV. Each specimen was tested with the third-generation branched DNA (bDNA) assay, CAP/CTM HCV, and CAP/CTM HCV v2.0. The HCV RNA level was lower in CAP/CTM HCV than in bDNA in 76.2% of cases, regardless of the HCV genotype 4 subtype. In contrast, the correlation between bDNA and CAP/CTM HCV v2.0 values was excellent. CAP/CTM HCV v2.0 accurately quantified HCV RNA levels in the presence of an A-to-T substitution at position 165 alone or combined with a G-to-A substitution at position 145 of the 5' untranslated region of HCV genome. In conclusion, CAP/CTM HCV v2.0 accurately quantifies HCV RNA in genotype 4 clinical specimens, regardless of the subtype, and can be confidently used in clinical trials and clinical practice with this genotype.

Understanding the molecular mechanism(s) of hepatitis C virus (HCV) induced interferon resistance.

PubMed

Qashqari, Hanadi; Al-Mars, Amany; Chaudhary, Adeel; Abuzenadah, Adel; Damanhouri, Ghazi; Alqahtani, Mohammed; Mahmoud, Maged; El Sayed Zaki, Maysaa; Fatima, Kaneez; Qadri, Ishtiaq

2013-10-01

Hepatitis C virus (HCV) is one of the foremost causes of chronic liver disease affecting over 300 million globally. HCV contains a positive-stranded RNA of ~9600 nt and is surrounded by the 5' and 3'untranslated regions (UTR). The only successful treatment regimen includes interferon (IFN) and ribavirin. Like many other viruses, HCV has also evolved various mechanisms to circumvent the IFN response by blocking (1) downstream signaling actions via STAT1, STAT2, IRF9 and JAK-STAT pathways and (2) repertoire of IFN Stimulatory Genes (ISGs). Several studies have identified complex host demographic and genetic factors as well as viral genetic heterogeneity associated with outcomes of IFN therapy. The genetic predispositions of over 2000 ISGS may render the patients to become resistant, thus identification of such parameters within a subset of population are necessary for management corollary. The ability of various HCV genotypes to diminish IFN antiviral responses plays critical role in the establishment of chronic infection at the acute stage of infection, thus highlighting importance of the resistance in HCV treated groups. The recently defined role of viral protein such as C, E2, NS3/NS4 and NS5A proteins in inducing the IFN resistance are discussed in this article. How the viral and host genetic composition and epistatic connectivity among polymorphic genomic sites synchronizes the evolutionary IFN resistance trend remains under investigation. However, these signals may have the potential to be employed for accurate prediction of therapeutic outcomes. In this review article, we accentuate the significance of host and viral components in IFN resistance with the aim to determine the successful outcome in patients. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of multiple myeloma in a patient with chronic hepatitis C: A case report and review of the literature

PubMed Central

Lakatos, Peter Laszlo; Fekete, Sandor; Horanyi, Margit; Fischer, Simon; Abonyi, Margit E

2006-01-01

An association between chronic hepatitis C virus (HCV) infection and essential mixed cryoglobulinaemia and non-Hodgkin lymphoma (NHL) has been suggested. However, a causative role of HCV in these conditions has not been established. The authors report a case of a 50 year-old woman with chronic hepatitis C (CHC) who has been followed up since 1998 due to a high viral load, genotype 1b and moderately elevated liver function tests (LFTs). Laboratory data and liver biopsy revealed moderate activity (grade: 5/18, stage: 1/6). In April 1999, one-year interferon therapy was started. HCV-RNA became negative with normalization of LFTs. However, the patient relapsed during treatment. In September 2002, the patient was admitted for chronic back pain. A CT examination demonstrated degenerative changes. In March 2003, multiple myeloma was diagnosed (IgG-kappa, bone ma-rrow biopsy: 50% plasma cell infiltration). MRI revealed a compression fracture of the 5th lumbar vertebral body and an abdominal mass in the right lower quadrant, infiltrating the canalis spinalis. Treatment with vincristine, adriamycin and dexamethasone (VAD) was started and bisphosphonate was administered regularly. In January 2004, after six cycles of VAD therapy, the multiple myeloma regressed. Thalidomide, as a second line trea-tment of refractory multiple myeloma (MM) was initiated, and followed by peginterferon-α2b and ribavirin against the HCV infection in June. In June 2005, LFTs returned to normal, while HCV-RNA was negative, demonstrating an end of treatment response. Although a pathogenic role of HCV infection in malignant lymphoproliferative disorders has not been established, NHL and possibly MM may develop in CHC patients, supporting a role of a complex follow-up in these patients. PMID:16610042

"Hep C, where art thou": What are the remaining (fundable) questions in hepatitis C virus research?

PubMed

Rosen, Hugo Ramón

2017-01-01

Hepatitis C virus (HCV) has dominated the field of hepatology for the past 25 years, and its cure in the majority of treated patients is one of the greatest achievements in all of medicine. However, the latter has led to the belief by some that HCV research should be shelved for other, more pressing areas. The mission for HCV eradication is far from accomplished. As a historical reference, we should consider that disease elimination has required vaccination with all previously controlled infections including smallpox and polio and that simple, effective treatment is not sufficient in most infections to lead to substantial control. Syphilis is the best example, for which a single dose of penicillin (which literally costs pennies and that we have had since 1945) is curative in early stages. Not only have we not eradicated syphilis, rates of infection have increased in many places within the United States in recent years. Most HCV-infected subjects are unaware of their infection, remaining at risk for transmission to others and disease progression, including cirrhosis and hepatocellular carcinoma. In the era of highly effective direct-acting antivirals (DAAs), many questions pertaining to HCV remain, but they are more complex and difficult to answer. Here, I provide my perspective on some of these salient issues: the residual risk for disease progression after sustained virologic response, the optimal approach to current DAA failures, the impact of targeting people who inject drugs with DAAs, vaccine prospects, and application of neutralizing HCV glycoprotein antibodies. (Hepatology 2017;65:341-349). © 2016 by the American Association for the Study of Liver Diseases.

Molecular Survey of Hepatitis C Virus in the Touristic City of Mar Del Plata, Argentina

PubMed Central

Culasso, Andrés C. A.; Elizalde, Mercedes; Campos, Rodolfo H.; Barbini, Luciana

2012-01-01

The global epidemiology of Hepatitis C Virus (HCV) may be roughly described by two groups of genotypes: the worldwide distributed ones (subtypes 1a, 1b, 2a and 3a, among others) and the endemic ones (subtypes 4a, 5a, 6a, among others). Epidemiological and population dynamic studies of the worldwide distributed genotypes have shown that subtypes 1a and 3a are common among intravenous drug users (IDUs) and that they are also in expansion in some countries. The molecular survey of HCV provides some clues about the epidemiological status of the infections in a local scale and the phylogenetic and demographic reconstruction analyses complement this study by inferring whether the infections of certain subtypes are in a steady state or expanding. Here, a molecular survey of the HCV variants that circulate in the touristic city of Mar del Plata (Buenos Aires, Argentina) was performed in samples obtained from 42 patients. The subtypes detected were 1a (32 patients), 3a (8 patients) and 1b (2 patients). The demographic history of subtype 1a inferred using the sequence data showed an exponential growth in the 1990′s. The period of viral expansion was delayed compared with that observed for the same genotype in other countries where the transmission was associated with IDUs. Also, the phylogeographic analysis of HCV-1a showed a statistically significant association between the location of the samples and the phylogeny, which may be the result of the local transmission of HCV in the city. The molecular analysis helped in the description of the complex epidemiological context of a touristic city, and pointed out that some sanitary measures should be taken in order to reduce the transmission of HCV (and maybe of HIV) among IDUs. PMID:23028605

Potent Inhibitors of the Hepatitis C Virus NS3 Protease: Design and Synthesis of Macrocyclic Substrate-Based [beta]-Strand Mimics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goudreau, Nathalie; Brochu, Christian; Cameron, Dale R.

2008-06-30

The virally encoded NS3 protease is essential to the life cycle of the hepatitis C virus (HCV), an important human pathogen causing chronic hepatitis, cirrhosis of the liver, and hepatocellular carcinoma. The design and synthesis of 15-membered ring {beta}-strand mimics which are capable of inhibiting the interactions between the HCV NS3 protease enzyme and its polyprotein substrate will be described. The binding interactions between a macrocyclic ligand and the enzyme were explored by NMR and molecular dynamics, and a model of the ligand/enzyme complex was developed.

Coevolution analysis of Hepatitis C virus genome to identify the structural and functional dependency network of viral proteins

NASA Astrophysics Data System (ADS)

Champeimont, Raphaël; Laine, Elodie; Hu, Shuang-Wei; Penin, Francois; Carbone, Alessandra

2016-05-01

A novel computational approach of coevolution analysis allowed us to reconstruct the protein-protein interaction network of the Hepatitis C Virus (HCV) at the residue resolution. For the first time, coevolution analysis of an entire viral genome was realized, based on a limited set of protein sequences with high sequence identity within genotypes. The identified coevolving residues constitute highly relevant predictions of protein-protein interactions for further experimental identification of HCV protein complexes. The method can be used to analyse other viral genomes and to predict the associated protein interaction networks.

Prevalence of occult hepatitis C infection in chronic hemodialysis and kidney transplant patients.

PubMed

Baid-Agrawal, Seema; Schindler, Ralf; Reinke, Petra; Staedtler, Adrienne; Rimpler, Sunda; Malik, Barbara; Frei, Ulrich; Berg, Thomas

2014-05-01

Detection of hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMC) and/or hepatocytes in absence of HCV RNA in serum, designated as 'occult HCV infection', has been a matter of controversy in recent years. We investigated for the first time the prevalence of occult HCV infection in large cohorts of chronic hemodialysis (CHD) and kidney transplant (KTx) patients. We enrolled 417 CHD patients, 417 KTx recipients and 2 control groups - 25 anti-HCV (antibody against HCV)-positive and HCV RNA-positive patients with chronic hepatitis C, and 40 anti-HCV-, HCV RNA-, and HBsAg-negative healthy subjects. HCV RNA was tested in serum and PBMC using a sensitive commercial assay. In CHD patients, the prevalence of anti-HCV was 3.6% (15/417) and of positive serum HCV RNA 2.4% (10/417). HCV RNA was detected in PBMC in 1/407 (0.25%) HCV serum RNA-negative patients ("occult HCV infection"). In KTx recipients, prevalence of anti-HCV was 4.8% (20/417) and of positive serum HCV RNA 4.6% (19/417). Occult HCV infection was found in 2/398 (0.5%) serum HCV RNA-negative patients. On a mean longitudinal follow-up of 30months of the 3 patients with occult HCV infection, there was no clinical or virological evidence of HCV infection. The prevalence of occult HCV infection was very low in our CHD and KTx patients, and it did not appear to be clinically relevant. Further studies in geographic populations with high HCV endemicity are required to clarify the significance of occult HCV infection in these patient groups. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Limited overlap between phylogenetic HIV and hepatitis C virus clusters illustrates the dynamic sexual network structure of Dutch HIV-infected MSM.

PubMed

Vanhommerig, Joost W; Bezemer, Daniela; Molenkamp, Richard; Van Sighem, Ard I; Smit, Colette; Arends, Joop E; Lauw, Fanny N; Brinkman, Kees; Rijnders, Bart J; Newsum, Astrid M; Bruisten, Sylvia M; Prins, Maria; Van Der Meer, Jan T; Van De Laar, Thijs J; Schinkel, Janke

2017-09-24

MSM are at increased risk for infection with HIV-1 and hepatitis C virus (HCV). Is HIV/HCV coinfection confined to specific HIV transmission networks? A HIV phylogenetic tree was constructed for 5038 HIV-1 subtype B polymerase (pol) sequences obtained from MSM in the AIDS therapy evaluation in the Netherlands cohort. We investigated the existence of HIV clusters with increased HCV prevalence, the HIV phylogenetic density (i.e. the number of potential HIV transmission partners) of HIV/HCV-coinfected MSM compared with HIV-infected MSM without HCV, and the overlap in HIV and HCV phylogenies using HCV nonstructural protein 5B sequences from 183 HIV-infected MSM with acute HCV infection. Five hundred and sixty-three of 5038 (11.2%) HIV-infected MSM tested HCV positive. Phylogenetic analysis revealed 93 large HIV clusters (≥10 MSM), 370 small HIV clusters (2-9 MSM), and 867 singletons with a median HCV prevalence of 11.5, 11.6, and 9.3%, respectively. We identified six large HIV clusters with elevated HCV prevalence (range 23.5-46.2%). Median HIV phylogenetic densities for MSM with HCV (3, interquartile range 1-7) and without HCV (3, interquartile range 1-8) were similar. HCV phylogeny showed 12 MSM-specific HCV clusters (clustersize: 2-39 HCV sequences); 12.7% of HCV infections were part of the same HIV and HCV cluster. We observed few HIV clusters with elevated HCV prevalence, no increase in the HIV phylogenetic density of HIV/HCV-coinfected MSM compared to HIV-infected MSM without HCV, and limited overlap between HIV and HCV phylogenies among HIV/HCV-coinfected MSM. Our data do not support the existence of MSM-specific sexual networks that fuel both the HIV and HCV epidemic.

Next-Generation Sequencing Reveals Frequent Opportunities for Exposure to Hepatitis C Virus in Ghana

PubMed Central

Phillips, Richard O.; Mora, Nallely; Xia, Guo-liang; Campo, David S.; Purdy, Michael A.; Dimitrova, Zoya E.; Owusu, Dorcas O.; Punkova, Lili T.; Skums, Pavel; Owusu-Ofori, Shirley; Sarfo, Fred Stephen; Vaughan, Gilberto; Roh, Hajung; Opare-Sem, Ohene K.; Cooper, Richard S.; Khudyakov, Yury E.

2015-01-01

Globally, hepatitis C Virus (HCV) infection is responsible for a large proportion of persons with liver disease, including cancer. The infection is highly prevalent in sub-Saharan Africa. West Africa was identified as a geographic origin of two HCV genotypes. However, little is known about the genetic composition of HCV populations in many countries of the region. Using conventional and next-generation sequencing (NGS), we identified and genetically characterized 65 HCV strains circulating among HCV-positive blood donors in Kumasi, Ghana. Phylogenetic analysis using consensus sequences derived from 3 genomic regions of the HCV genome, 5'-untranslated region, hypervariable region 1 (HVR1) and NS5B gene, consistently classified the HCV variants (n = 65) into genotypes 1 (HCV-1, 15%) and genotype 2 (HCV-2, 85%). The Ghanaian and West African HCV-2 NS5B sequences were found completely intermixed in the phylogenetic tree, indicating a substantial genetic heterogeneity of HCV-2 in Ghana. Analysis of HVR1 sequences from intra-host HCV variants obtained by NGS showed that three donors were infected with >1 HCV strain, including infections with 2 genotypes. Two other donors share an HCV strain, indicating HCV transmission between them. The HCV-2 strain sampled from one donor was replaced with another HCV-2 strain after only 2 months of observation, indicating rapid strain switching. Bayesian analysis estimated that the HCV-2 strains in Ghana were expanding since the 16th century. The blood donors in Kumasi, Ghana, are infected with a very heterogeneous HCV population of HCV-1 and HCV-2, with HCV-2 being prevalent. The detection of three cases of co- or super-infections and transmission linkage between 2 cases suggests frequent opportunities for HCV exposure among the blood donors and is consistent with the reported high HCV prevalence. The conditions for effective HCV-2 transmission existed for ~ 3–4 centuries, indicating a long epidemic history of HCV-2 in Ghana. PMID:26683463

"Immune activation, aging and gender" and progression of liver disease.

PubMed

Nasta, Paola

2011-08-01

Hepatitis C is the predominant cause of liver disease in the HIV-positive population and the most important of the non-AIDS-related causes of death. HCV disease tends to become chronic more frequently in HIV-positive subjects, and to evolve more rapidly into cirrhosis of the liver. The rapidity of the evolution varies considerably from one individual to the next and, if in HIV-negative subjects cirrhosis manifests itself after approx. 40-50 years of disease, in HIV-positive subjects it emerges 10-15 years earlier (1, 2). The severity of the fibrosis is not a gradual event and can be worsened by many factors. Age, sex, duration of the infection and assumption of alcohol are the most well-known variables; obesity, diabetes, steatosis and metabolic disorders are equally important factors that affect the progression of liver disease (3). The severity of the liver disease is very different in men compared to women. Being male is undoubtedly one of the factors most closely related to the gravity of fibrosis (4). In HCV mono-infected women, cirrhosis appears from the age of 60 onwards. With the onset of the menopause, in fact, the progression of liver disease accelerates and the risk of developing cirrhosis or cancer of the liver becomes particularly significant in women over 50. The conditions of menopause or of amenorrhea, irrespective of age, are therefore correlated with the progression of liver disease (5). This evidence led researchers to theorize on the possible anti-fibrogenic role of estrogens. In fact, estrogens in physiological doses in the plasma of women in fertile age contribute to controlling the progression of liver disease through antioxidant mechanisms and lipid peroxidation control mechanisms (6). The reduction of estrogens during the menopause is closely linked to the increase of metabolic disorders. During the menopause, steatosis and cardiovascular diseases increase in parallel with the increase of atherogenic lipoproteins, the accumulation ofintra-abdominal fat and the onset of insulin resistance (3, 7). Recent works have demonstrated how the concentration of HCV viremia in plasma correlates with the degree of insulin resistance and with the concentration of circulating triglycerides, demonstrating how the role of HCV in altering the hepatic lipid and glucide metabolism is functional to its replicative capacity. The correlation between the HCV viral load and the metabolic set-up is still unclear in the mono-infection and has been rarely studied in the HIV/HCV co-infection, where the picture is further altered by the metabolic impact of certain antiretroviral therapies. Over recent years, most of the HIV/HCV co-infected population, belonging - as is common knowledge - to the old intravenous drug user risk categories, have reached the age of 50 and have 20-25 years' history of liver disease. The women are reaching the menopause and are frequently characterized by prolonged states of amenorrhea. This conditions exposes HIV-positive women and the co-infected population, currently in care in our centres, to a sudden and rapid worsening of the liver condition. Over the last few years, we are also witnessing the launching on the market of new anti-HCV molecules which must, of necessity, find an outlet as new drug applications for HIV/HCV co-infected patients, as well as being used to the best advantage in populations with particular complications. (www.actabiomedica.it)

Comparison of a newly developed automated and quantitative hepatitis C virus (HCV) core antigen test with the HCV RNA assay for clinical usefulness in confirming anti-HCV results.

PubMed

Kesli, Recep; Polat, Hakki; Terzi, Yuksel; Kurtoglu, Muhammet Guzel; Uyar, Yavuz

2011-12-01

Hepatitis C virus (HCV) is a global health care problem. Diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies as a screening test with serum samples. Recombinant immunoblot assays are used as supplemental tests and for the final detection and quantification of HCV RNA in confirmatory tests. In this study, we aimed to compare the HCV core antigen test with the HCV RNA assay for confirming anti-HCV results to determine whether the HCV core antigen test may be used as an alternative confirmatory test to the HCV RNA test and to assess the diagnostic values of the total HCV core antigen test by determining the diagnostic specificity and sensitivity rates compared with the HCV RNA test. Sera from a total of 212 treatment-naive patients were analyzed for anti-HCV and HCV core antigen both with the Abbott Architect test and with the molecular HCV RNA assay consisting of a reverse transcription-PCR method as a confirmatory test. The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 96.3%, 100%, 100%, and 89.7%, respectively. The levels of HCV core antigen showed a good correlation with those from the HCV RNA quantification (r = 0.907). In conclusion, the Architect HCV antigen assay is highly specific, sensitive, reliable, easy to perform, reproducible, cost-effective, and applicable as a screening, supplemental, and preconfirmatory test for anti-HCV assays used in laboratory procedures for the diagnosis of hepatitis C virus infection.

Assessment of the clinical cardiac drug-drug interaction associated with the combination of hepatitis C virus nucleotide inhibitors and amiodarone in guinea pigs and rhesus monkeys.

PubMed

Regan, Christopher P; Morissette, Pierre; Regan, Hillary K; Travis, Jeffery J; Gerenser, Pamela; Wen, Jianzhong; Fitzgerald, Kevin; Gruver, Shaun; DeGeorge, Joseph J; Sannajust, Frederick J

2016-11-01

In 2015, European and U.S. health agencies issued warning letters in response to 9 reported clinical cases of severe bradycardia/bradyarrhythmia in hepatitis C virus (HCV)-infected patients treated with sofosbuvir (SOF) in combination with other direct acting antivirals (DAAs) and the antiarrhythmic drug, amiodarone (AMIO). We utilized preclinical in vivo models to better understand this cardiac effect, the potential pharmacological mechanism(s), and to identify a clinically translatable model to assess the drug-drug interaction (DDI) cardiac risk of current and future HCV inhibitors. An anesthetized guinea pig model was used to elicit a SOF+AMIO-dependent bradycardia. Detailed cardiac electrophysiological studies in this species revealed SOF+AMIO-dependent selective nodal dysfunction, with initial, larger effects on the sinoatrial node. Further studies in conscious, rhesus monkeys revealed an emergent bradycardia and bradyarrhythmia in 3 of 4 monkeys administered SOF+AMIO, effects not observed with either agent alone. Morever, bradycardia and bradyarrhythmia were not observed in rhesus monkeys when intravenous infusion of MK-3682 was completed after AMIO pretreatment. These are the first preclinical in vivo experiments reported to replicate the severe clinical SOF+AMIO cardiac DDI and provide potential in vivo mechanism of action. As such, these data provide a preclinical risk assessment paradigm, including a clinically relevant nonhuman primate model, with which to better understand cardiovascular DDI risk for this therapeutic class. Furthermore, these studies suggest that not all HCV DAAs and, in particular, not all HCV nonstructural protein 5B inhibitors may exhibit this cardiac DDI with amiodarone. Given the selective in vivo cardiac electrophysiological effect, these data enable targeted cellular/molecular mechanistic studies to more precisely identify cell types, receptors, and/or ion channels responsible for the clinical DDI. (Hepatology 2016;64:1430-1441). © 2016 by the American Association for the Study of Liver Diseases.

Emergence of drug resistance-associated variants and changes in serum lipid profiles in sofosbuvir plus ledipasvir-treated chronic hepatitis C patients.

PubMed

Kan, Hiromi; Imamura, Michio; Kawakami, Yoshiiku; Daijo, Kana; Teraoka, Yuji; Honda, Fumi; Nakamura, Yuki; Morio, Kei; Kobayashi, Tomoki; Nakahara, Takashi; Nagaoki, Yuko; Kawaoka, Tomokazu; Tsuge, Masataka; Aikata, Hiroshi; Hayes, Clair Nelson; Miki, Daiki; Ochi, Hidenori; Honda, Yoji; Mori, Nami; Takaki, Shintaro; Tsuji, Keiji; Chayama, Kazuaki

2017-11-01

Combination of sofosbuvir plus ledipasvir therapy has been expected to enhance sustained virological response (SVR) rates in hepatitis C virus (HCV) genotype 1 chronic infected patients. We analyzed the emergence of drug resistance-associated variants (RAVs) in treatment failure and changes in lipid profiles in sofosbuvir/ledipasvir-treated patients. A total of 176 patients with chronic HCV genotype 1 infection without decompensated liver cirrhosis were treated with sofosbuvir/ledipasvir for 12 weeks. NS5A and NS5B RAVs were determined by either Invader assay or direct sequencing. Serum lipid-related markers were measured at the start of treatment and at week 4 in patients who received sofosbuvir/ledipasvir and ombitasvir/paritaprevir/ritonavir therapies. SVR was achieved in 94.9% (167 out of 176) of patients. SVR12 rate was 97.1% for patietns with low frequncy (<25%) of baseline NS5A RAVs, but 82.8% for patients with high frequency (>75%) of NS5A RAVs. In multivariate regression analysis, higher albumin (odds ratio [OR] = 0.020 for presence; P = 0.007), and NS5A-L31/Y93 RAVs with a population frequency <75% (OR = 29.860 for presence; P = 0.023) were identified as significant independent predictors for SVR12. NS5A-Y93H substitutions were detected in all nine treatment failures at HCV relapse, and three out of six patients with NS5A inhibitor-naïve patients achieved additional NS5A RAVs. Serum low-density lipoprotein cholesterol and apolipoprotein B levels were significantly elevated at week 4 in sofosbuvir/ledipasvir-treated patients. These elevations were greater than in ombitasvir/paritaprevir/ritonavir-treated patients. In conclusion, NS5A multi-RAVs are likely to develop in patients who fail to respond to sofosbuvir/ledipasvir therapy. Inhibition of HCV replication with sofosbuvir might affect lipid metabolism. © 2017 Wiley Periodicals, Inc.

Environmental triggers of thyroiditis: hepatitis C and interferon-α.

PubMed

Menconi, F; Hasham, A; Tomer, Y

2011-01-01

Autoimmune thyroid diseases (AITD) are postulated to develop as a result of a complex interplay between several genetic and environmental influences. The pathogenesis of AITD is still not clearly defined. However, among the implicated triggers (e.g. iodine, infections, medications), more recent data confirmed strong associations of AITD with the hepatitis C virus (HCV) infection and interferon-α (IFNα) therapy. Moreover, it is likely that HCV and IFN act in synergism to trigger AITD in patients. Indeed, approximately 40% of HCV patients develop either clinical or subclinical disease while receiving IFNα. Interferon induced thyroiditis (IIT) can manifest as non-autoimmune thyroiditis (presenting as destructive thyroiditis, or non-autoimmune hypothyroidism), or autoimmune thyroiditis [presenting with clinical features of Graves' disease (GD) or Hashimoto's thyroiditis (HT)]. Although not yet clearly understood, it is thought that IFNα can induce thyroiditis via both immune stimulatory and direct toxic effects on the thyroid. In view of the high frequency of IIT, routine screening and surveillance of HCV patients receiving IFNα is recommended to avoid the complications, such as cardiac arrhythmias, associated with thyrotoxicosis. In summary, IIT is a common clinical problem that can be readily diagnosed with routine thyroid function screening of HCV patients receiving IFN. The treatment of IIT consists of the standard therapy for differing clinical manifestations of IIT such as GD, HT, or destructive thyroiditis. However, anti-thyroid medications are not recommended in this setting since they can potentially be hepatotoxic.

Exosome-associated hepatitis C virus in cell cultures and patient plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ziqing; Zhang, Xiugen; Yu, Qigui

Highlights: • HCV occurs in both exosome-free and exosome-associated forms. • Exosome-associated HCV is infectious and resistant to neutralizing antibodies. • More exosome-associated HCV than exosome-free HCV is present in patient plasma. - Abstract: Hepatitis C virus (HCV) infects its target cells in the form of cell-free viruses and through cell–cell contact. Here we report that HCV is associated with exosomes. Using highly purified exosomes and transmission electron microscopic imaging, we demonstrated that HCV occurred in both exosome-free and exosome-associated forms. Exosome-associated HCV was infectious and resistant to neutralization by an anti-HCV neutralizing antibody. There were more exosome-associated HCV thanmore » exosome-free HCV detected in the plasma of HCV-infected patients. These results suggest exosome-associated HCV as an alternative form for HCV infection and transmission.« less

Hepatitis C virus (HCV) antibody dynamics following acute HCV infection and reinfection among HIV-infected men who have sex with men.

PubMed

Vanhommerig, Joost W; Thomas, Xiomara V; van der Meer, Jan T M; Geskus, Ronald B; Bruisten, Sylvia M; Molenkamp, Richard; Prins, Maria; Schinkel, Janke

2014-12-15

A decline of hepatitis C virus (HCV) antibody titers (anti-HCV), ultimately resulting in seroreversion, has been reported following clearance of viremia in both acute and chronic HCV infection. However, frequency of seroreversion remains unknown in human immunodeficiency virus (HIV)/HCV-coinfected patients. We describe anti-HCV dynamics among HIV-infected men who have sex with men (MSM) following acute HCV infection and reinfection. Primary acute HCV infection was assumed when a subject was anti-HCV negative prior to the first positive HCV RNA test. Anti-HCV was measured at least annually in 63 HIV-infected MSM, with a median follow-up of 4.0 years (interquartile range [IQR], 2.5-5.7 years). Time from HCV infection to seroconversion, and from seroconversion to seroreversion, was estimated using the Kaplan-Meier method. Longitudinal anti-HCV patterns were studied using a random-effects model to adjust for repeated measures. Median time from HCV infection to seroconversion was 74 days (IQR, 47-125 days). Subjects who cleared HCV RNA (n = 36) showed a significant decrease in anti-HCV levels (P < .001). Among 31 subjects with sustained virologic response (SVR), anti-HCV became undetectable during follow-up in 8; cumulative incidence of seroreversion within 3 years after seroconversion was 37% (95% confidence interval, 18%-66%). Eighteen subjects became reinfected during follow-up; this coincided with a subsequent increase in anti-HCV reactivity. A decline of anti-HCV reactivity was associated with HCV RNA clearance. Seroreversion was very common following SVR. Upon reinfection, anti-HCV levels increased again. Monitoring anti-HCV levels might therefore be an effective alternative for diagnosis of HCV reinfection. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Timeline: Targeted Treatment of Hepatitis C Virus.

PubMed

Teitzel, Gail

2016-09-22

Chronic hepatitis C virus infection can cause liver cirrhosis and cancer, and early treatment options were non-specific and could be toxic. Work aimed at elucidating the viral life cycle has led to better treatment options through the development of direct-acting antivirals, as exemplified by the work of Ralf Bartenschlager, Charles Rice, and Michael Sofia who have received the Lasker∼DeBakey Clinical Medical Research Award for their work on this effort. Key events in understanding HCV replication and development of direct-acting antivirals are shown in this Timeline. Copyright © 2016 Elsevier Inc. All rights reserved.

Examination of the Hepatitis C Virus care continuum among individuals with an opioid use disorder in substance use treatment.

PubMed

Brown, Jennifer L; Gause, Nicole K; Lewis, Daniel; Winhusen, Theresa

2017-05-01

Hepatitis C Virus (HCV) risk is elevated for individuals with an opioid use disorder (OUD). Routine HCV testing is recommended for high-risk individuals, including those with an injection drug use history. HCV antibody testing addresses the first step in the HCV treatment care cascade, with uptake and completion of HCV treatment among individuals with chronic HCV as the optimal care cascade endpoint. The aim of this study was to characterize self-reported HCV treatment cascade outcomes among individuals with an OUD in outpatient medication assisted treatment (MAT). Individuals receiving methadone or buprenorphine treatment (N=202, 67.8% female, M age=35.0, SD=8.4) completed a brief, anonymous paper-and-pencil survey examining self-reported history of HCV testing, diagnosis, and treatment. Descriptive statistics characterized HCV treatment cascade outcomes. A majority (79.3%) endorsed a lifetime HCV testing history; 34.9% were tested for HCV during the past year. Of those with a lifetime HCV testing history, 42.7% indicated they have been told they have HCV (n=67/157), with 21% (n=14/67) of those individuals reporting that they have been told they have chronic HCV, and 71.4% (n=10/14) of those with chronic HCV reporting receipt of HCV treatment. Results underscore gaps in the HCV care continuum among individuals with OUD in MAT. Interventions to increase uptake of HCV testing, communication of HCV diagnostic and treatment information by medical providers, linkage to HCV medical care, and uptake and adherence to HCV treatment are urgently needed, particularly among individuals with an OUD in MAT. Copyright © 2017 Elsevier Inc. All rights reserved.

Generation and Characterization of Monoclonal Antibodies against a Cyclic Variant of Hepatitis C Virus E2 Epitope 412-422

PubMed Central

Sandomenico, Annamaria; Leonardi, Antonio; Berisio, Rita; Sanguigno, Luca; Focà, Giuseppina; Focà, Annalia; Ruggiero, Alessia; Doti, Nunzianna; Muscariello, Livio; Barone, Daniela; Farina, Claudio; Owsianka, Ania; Vitagliano, Luigi

2016-01-01

ABSTRACT The hepatitis C virus (HCV) E2 envelope glycoprotein is crucial for virus entry into hepatocytes. A conserved region of E2 encompassing amino acids 412 to 423 (epitope I) and containing Trp420, a residue critical for virus entry, is recognized by several broadly neutralizing antibodies. Peptides embodying this epitope I sequence adopt a β-hairpin conformation when bound to neutralizing monoclonal antibodies (MAbs) AP33 and HCV1. We therefore generated new mouse MAbs that were able to bind to a cyclic peptide containing E2 residues 412 to 422 (C-epitope I) but not to the linear counterpart. These MAbs bound to purified E2 with affinities of about 50 nM, but they were unable to neutralize virus infection. Structural analysis of the complex between C-epitope I and one of our MAbs (C2) showed that the Trp420 side chain is largely buried in the combining site and that the Asn417 side chain, which is glycosylated in E2 and solvent exposed in other complexes, is slightly buried upon C2 binding. Also, the orientation of the cyclic peptide in the antibody-combining site is rotated by 180° compared to the orientations of the other complexes. All these structural features, however, do not explain the lack of neutralization activity. This is instead ascribed to the high degree of selectivity of the new MAbs for the cyclic epitope and to their inability to interact with the epitope in more flexible and extended conformations, which recent data suggest play a role in the mechanisms of neutralization escape. IMPORTANCE Hepatitis C virus (HCV) remains a major health care burden, affecting almost 3% of the global population. The conserved epitope comprising residues 412 to 423 of the viral E2 glycoprotein is a valid vaccine candidate because antibodies recognizing this region exhibit potent neutralizing activity. This epitope adopts a β-hairpin conformation when bound to neutralizing MAbs. We explored the potential of cyclic peptides mimicking this structure to elicit anti-HCV antibodies. MAbs that specifically recognize a cyclic variant of the epitope bind to soluble E2 with a lower affinity than other blocking antibodies and do not neutralize virus. The structure of the complex between one such MAb and the cyclic epitope, together with new structural data showing the linear peptide bound to neutralizing MAbs in extended conformations, suggests that the epitope displays a conformational flexibility that contributes to neutralization escape. Such features can be of major importance for the design of epitope-based anti-HCV vaccines. PMID:26819303

Sustained virological response and its treatment predictors in hepatitis C virus genotype 4 compared to genotypes 1, 2, and 3: a meta-analysis.

PubMed

Yee, Brittany E; Nguyen, Nghia H; Zhang, Bing; Lin, Derek; Vutien, Philip; Wong, Carrie R; Lutchman, Glen A; Nguyen, Mindie H

2015-01-01

Pegylated interferon and ribavirin (PEG-IFN+RBV) may be more cost-effective than direct-acting antivirals in resource-limited settings. Current literature suggests sustained virological response (SVR) in hepatitis C virus genotype 4 (HCV-4) is similar to genotype 1 (HCV-1), but worse than 2 and 3 (HCV-2/3). However, few studies have compared treatment response between these groups and these have been limited by small sample sizes with heterogeneous designs. We performed a meta-analysis of SVR predictors in HCV-4 versus HCV-1, 2, and 3 patients treated with PEG-IFN+RBV. In November 2013, we searched for 'genotype 4' in MEDLINE/EMBASE databases and scientific conferences. We included original articles with ≥25 treatment-naïve HCV-4 and comparisons to HCV-1, 2, and/or 3 patients treated with PEG-IFN+RBV. Random effects modelling was used with heterogeneity defined by Cochrane Q-test (p value<0.10) and I(2) statistic (>50%). Five studies with 20 014 patients (899 HCV-4; 12 033 HCV-1; and 7082 HCV-2/3 patients) were included. SVR was 53% (CI 43% to 62%) for HCV-4, 44% (CI 40% to 47%) for HCV-1; and 73% (CI 58% to 84%) for HCV-2/3. SVR with EVR (early virological response) was 75% (CI 61% to 86%) in HCV-4; 64% (CI 46% to 79%) in HCV-1; and 85% (CI 71% to 93%) in HCV-2/3. SVR without EVR was 10% (CI 6% to 17%) for HCV-4; 13% (CI 12% to 15%) for HCV-1; and 23% (CI 16% to 33%) for HCV-2/3. SVR rates are similar in HCV-4 (∼50%) and HCV-1 (∼40%). Lack of EVR is a good stopping rule for HCV-4 and HCV-1 since only 10% subsequently achieve SVR. In HCV-4 patients with EVR, three-quarters can expect to achieve SVR with PEG-IFN+RBV.

Hepatitis C Virus Testing and Linkage to Care in North Carolina and South Carolina Jails, 2012–2014

PubMed Central

Smith, Bryce D.; Seña, Arlene C.; Hilton, Alison; Bachman, Sallie; Lunda, Mulamba; Spaulding, Anne C.

2016-01-01

Objective We evaluated a hepatitis C virus (HCV) testing and linkage-to-care post-release program among detainees of small- to medium-sized jails in North Carolina and South Carolina as part of the Hepatitis Testing and Linkage to Care initiative. Methods An HCV testing and linkage-to-care program was implemented in selected jails in North Carolina and South Carolina from December 2012 to March 2014. Health-care workers not affiliated with the jails conducted HCV antibody (anti-HCV) and HCV ribonucleic acid (RNA) testing and linkage-to-care activities. The North Carolina jail provided universal opt-out testing for HCV; South Carolina jails initially targeted high-risk individuals before expanding to routine testing. Results Of 669 detainees tested for HCV in North Carolina, 88 (13.2%) tested anti-HCV positive, of whom 81 (92.0%) received an HCV RNA test, 66 (81.5%) of whom tested HCV RNA positive (i.e., currently infected). Of the 66 detainees with current HCV infection, 18 were referred to HCV medical care post-release and 10 attended their first appointment. Of 224 detainees tested for HCV in South Carolina, 18 (8.0%) tested anti-HCV positive, of whom 13 received an HCV RNA test. Nine of 13 detainees tested HCV RNA positive, seven detainees were referred to post-release medical care, and two detainees attended their first appointment. Overall, 106 of 893 (11.9%) detainees were anti-HCV positive. Conclusion This study demonstrated that HCV testing, identification of infection, and linkage to care are feasible among jail populations. The rate of anti-HCV positivity was lower than that found in national studies of incarcerated populations, suggesting that HCV infection prevalence in jails may vary across U.S. states or regions. PMID:27168668

HIV Infection Status as a Predictor of Hepatitis C Virus RNA Testing in Primary Care

PubMed Central

Yartel, Anthony K.; Morgan, Rebecca L.; Rein, David B.; Brown, Kimberly Ann; Kil, Natalie B.; Massoud, Omar I.; Fallon, Michael B.; Smith, Bryce D.

2015-01-01

Introduction Receipt of hepatitis C virus (HCV) RNA testing following a positive HCV antibody (anti-HCV+) test result to establish current infection is a quality indicator for HCV-related care. This study examines HIV infection status as a predictor of HCV RNA test receipt after an anti-HCV+ result in the primary care setting. Methods Electronic medical records of anti-HCV+ patients from a multisite retrospective study of patients aged ≥18 years who utilized one or more primary care outpatient services during 2005–2010 were analyzed in 2014. A multivariable logistic regression model examined the independent relationships between patient characteristics and receipt of HCV RNA testing. Results Among 1,115 anti-HCV+ patients, 133 (11.9%) were also HIV-positive. Of these, 77.4% (n=103) underwent HCV RNA testing to determine current infection status. By contrast, 66.7% (n=654/980) of anti-HCV+ patients who were HIV-negative received HCV RNA testing. Following multivariable adjustment, the odds of receiving HCV RNA testing were higher among anti-HCV+ patients who were also HIV-positive (AOR=1.9, 95% CI=1.2, 3.0), compared with their HIV-negative counterparts. Elevated alanine aminotransferase level was also associated with receipt of HCV RNA testing (AOR=1.9, 95% CI=1.4, 2.4). Black race was associated with decreased odds of receiving HCV RNA testing (AOR=0.7, 95% CI=0.5, 1.0). Conclusions HIV infection status is independently associated with the likelihood of receiving HCV RNA testing following an anti-HCV+ result. One quarter of anti-HCV+ patients who were also HIV-positive and one third of their HIV-negative counterparts, respectively, did not receive testing to establish active HCV infection, which is imperative for appropriate care and treatment. PMID:25896194

Occult hepatitis C virus infection in patients in whom the etiology of persistently abnormal results of liver-function tests is unknown.

PubMed

Castillo, Inmaculada; Pardo, Margarita; Bartolomé, Javier; Ortiz-Movilla, Nuria; Rodríguez-Iñigo, Elena; de Lucas, Susana; Salas, Clara; Jiménez-Heffernan, Jose A; Pérez-Mota, Arturo; Graus, Javier; López-Alcorocho, Juan Manuel; Carreño, Vicente

2004-01-01

There are patients in whom the etiology of long-standing abnormal results of liver-function tests is unknown (ALF-EU) after exclusion of all known causes of liver diseases. We analyzed the presence of hepatitis C virus (HCV) RNA in liver-biopsy specimens from 100 patients who were negative for anti-HCV antibodies and for serum HCV RNA and who had ALF-EU. HCV RNA status was tested by reverse-transcription polymerase chain reaction (RT-PCR) and by in situ hybridization, in liver and peripheral-blood mononuclear cells (PBMCs). HCV RNA was detected in liver-biopsy specimens from 57 of 100 patients negative for anti-HCV antibodies and for serum HCV RNA (i.e., who had occult HCV infection). HCV RNA of negative polarity was found in the liver of 48 (84.2%) of these 57 patients with occult HCV infection. Nucleotide-sequence analysis confirmed the specificity of detection of HCV RNA and that patients were infected with the HCV 1b genotype. Of these 57 patients with intrahepatic HCV RNA, 40 (70%) had viral RNA in their PBMCs. With regard to liver histology, patients with occult HCV infection were more likely to have necroinflammatory activity (P=.017) and fibrosis (P=.022) than were patients without intrahepatic HCV RNA. Patients with ALF-EU may have intrahepatic HCV RNA in the absence of anti-HCV antibodies and of serum HCV RNA.

Agent-based model forecasts aging of the population of people who inject drugs in metropolitan Chicago and changing prevalence of hepatitis C infections

DOE PAGES

Gutfraind, Alexander; Boodram, Basmattee; Prachand, Nikhil; ...

2015-09-30

People who inject drugs (PWID) are at high risk for blood-borne pathogens transmitted during the sharing of contaminated injection equipment, particularly hepatitis C virus (HCV). HCV prevalence is influenced by a complex interplay of drug-use behaviors, social networks, and geography, as well as the availability of interventions, such as needle exchange programs. To adequately address this complexity in HCV epidemic forecasting, we have developed a computational model, the Agent-based Pathogen Kinetics model (APK). APK simulates the PWID population in metropolitan Chicago, including the social interactions that result in HCV infection. We used multiple empirical data sources on Chicago PWID tomore » build a spatial distribution of an in silico PWID population and modeled networks among the PWID by considering the geography of the city and its suburbs. APK was validated against 2012 empirical data (the latest available) and shown to agree with network and epidemiological surveys to within 1%. For the period 2010–2020, APK forecasts a decline in HCV prevalence of 0.8% per year from 44(±2)% to 36(±5)%, although some sub-populations would continue to have relatively high prevalence, including Non-Hispanic Blacks, 48(±5)%. The rate of decline will be lowest in Non-Hispanic Whites and we find, in a reversal of historical trends, that incidence among non-Hispanic Whites would exceed incidence among Non-Hispanic Blacks (0.66 per 100 per years vs 0.17 per 100 person years). APK also forecasts an increase in PWID mean age from 35(±1) to 40(±2) with a corresponding increase from 59(±2)% to 80(±6)% in the proportion of the population >30 years old. As a result, our studies highlight the importance of analyzing subpopulations in disease predictions, the utility of computer simulation for analyzing demographic and health trends among PWID and serve as a tool for guiding intervention and prevention strategies in Chicago, and other major cities.« less

Agent-based model forecasts aging of the population of people who inject drugs in metropolitan Chicago and changing prevalence of hepatitis C infections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutfraind, Alexander; Boodram, Basmattee; Prachand, Nikhil

People who inject drugs (PWID) are at high risk for blood-borne pathogens transmitted during the sharing of contaminated injection equipment, particularly hepatitis C virus (HCV). HCV prevalence is influenced by a complex interplay of drug-use behaviors, social networks, and geography, as well as the availability of interventions, such as needle exchange programs. To adequately address this complexity in HCV epidemic forecasting, we have developed a computational model, the Agent-based Pathogen Kinetics model (APK). APK simulates the PWID population in metropolitan Chicago, including the social interactions that result in HCV infection. We used multiple empirical data sources on Chicago PWID tomore » build a spatial distribution of an in silico PWID population and modeled networks among the PWID by considering the geography of the city and its suburbs. APK was validated against 2012 empirical data (the latest available) and shown to agree with network and epidemiological surveys to within 1%. For the period 2010–2020, APK forecasts a decline in HCV prevalence of 0.8% per year from 44(±2)% to 36(±5)%, although some sub-populations would continue to have relatively high prevalence, including Non-Hispanic Blacks, 48(±5)%. The rate of decline will be lowest in Non-Hispanic Whites and we find, in a reversal of historical trends, that incidence among non-Hispanic Whites would exceed incidence among Non-Hispanic Blacks (0.66 per 100 per years vs 0.17 per 100 person years). APK also forecasts an increase in PWID mean age from 35(±1) to 40(±2) with a corresponding increase from 59(±2)% to 80(±6)% in the proportion of the population >30 years old. As a result, our studies highlight the importance of analyzing subpopulations in disease predictions, the utility of computer simulation for analyzing demographic and health trends among PWID and serve as a tool for guiding intervention and prevention strategies in Chicago, and other major cities.« less

Agent-Based Model Forecasts Aging of the Population of People Who Inject Drugs in Metropolitan Chicago and Changing Prevalence of Hepatitis C Infections

PubMed Central

Prachand, Nikhil; Hailegiorgis, Atesmachew; Dahari, Harel; Major, Marian E.

2015-01-01

People who inject drugs (PWID) are at high risk for blood-borne pathogens transmitted during the sharing of contaminated injection equipment, particularly hepatitis C virus (HCV). HCV prevalence is influenced by a complex interplay of drug-use behaviors, social networks, and geography, as well as the availability of interventions, such as needle exchange programs. To adequately address this complexity in HCV epidemic forecasting, we have developed a computational model, the Agent-based Pathogen Kinetics model (APK). APK simulates the PWID population in metropolitan Chicago, including the social interactions that result in HCV infection. We used multiple empirical data sources on Chicago PWID to build a spatial distribution of an in silico PWID population and modeled networks among the PWID by considering the geography of the city and its suburbs. APK was validated against 2012 empirical data (the latest available) and shown to agree with network and epidemiological surveys to within 1%. For the period 2010–2020, APK forecasts a decline in HCV prevalence of 0.8% per year from 44(±2)% to 36(±5)%, although some sub-populations would continue to have relatively high prevalence, including Non-Hispanic Blacks, 48(±5)%. The rate of decline will be lowest in Non-Hispanic Whites and we find, in a reversal of historical trends, that incidence among non-Hispanic Whites would exceed incidence among Non-Hispanic Blacks (0.66 per 100 per years vs 0.17 per 100 person years). APK also forecasts an increase in PWID mean age from 35(±1) to 40(±2) with a corresponding increase from 59(±2)% to 80(±6)% in the proportion of the population >30 years old. Our studies highlight the importance of analyzing subpopulations in disease predictions, the utility of computer simulation for analyzing demographic and health trends among PWID and serve as a tool for guiding intervention and prevention strategies in Chicago, and other major cities. PMID:26421722

Re-re-treatment of hepatitis C virus: Eight patients who relapsed twice after direct-acting-antiviral drugs

PubMed Central

Hartman, Joshua; Bichoupan, Kian; Patel, Neal; Chekuri, Sweta; Harty, Alyson; Dieterich, Douglas; Perumalswami, Ponni; Branch, Andrea D

2015-01-01

AIM: To determine risk factors associated with hepatitis C virus (HCV) treatment failure after direct acting antivirals in patients with complex treatment histories. METHODS: All HCV mono-infected patients who received treatment at our institution were queried. Analysis was restricted to patients who previously failed treatment with boceprevir (BOC) or telaprevir (TVR) and started simeprevir (SMV) and sofosbuvir (SOF) ± ribavirin (RBV) between December 2013 and June 2014. Patients with human immunodeficiency virus (HIV)/HCV co-infection or patients who received a liver transplant in the past were excluded. Viral loads were recorded while on treatment and after treatment. Data collection continued until December, 31st 2014 when data analysis was initiated. Patients missing virologic outcomes data were not included in the analysis. Analysis of 35 patients who had virologic outcome data available resulted in eight patients who were viral load negative at the end of treatment with SMF/SOF but later relapsed. Data related to patient demographics, HCV infection, and treatment history was collected in order to identify risk factors shared among patients who failed treatment with SMF/SOF. RESULTS: Eight patients who were treated with the first generation HCV protease inhibitors BOC or TVR in combination with pegylated-interferon (PEG) and RBV who failed this triple therapy were subsequently re-treated with an off-label all-oral regimen of SMV and SOF for 12 wk, with RBV in seven cases. Treatment was initiated before the Food and Drug Administration approved a 24-wk SMV/SOF regimen for patients with liver cirrhosis. All eight patients had an end of treatment response, but later relapsed. Eight (100%) patients were male. Mean age was 56 (range, 49-64). Eight (100%) patients had previously failed PEG/RBV dual therapy at least once in addition to prior failure with triple therapy. Total number of times treated ranged from 3-6 (mean 3.8). Eight (100%) patients were male had liver cirrhosis as determined by Fibroscan or MRI. Seven (87.5%) patients had genotype 1a HCV. Seven (87.5%) patients had over 1 million IU/mL HCV RNA at the time of re-treatment. CONCLUSION: This study identifies factors associated with SMV/SOF treatment failure and provides evidence that twleve weeks of SMV/SOF/RBV is insufficient in cirrhotics with high-titer genotype 1a HCV. PMID:26604650

Re-re-treatment of hepatitis C virus: Eight patients who relapsed twice after direct-acting-antiviral drugs.

PubMed

Hartman, Joshua; Bichoupan, Kian; Patel, Neal; Chekuri, Sweta; Harty, Alyson; Dieterich, Douglas; Perumalswami, Ponni; Branch, Andrea D

2015-11-21

To determine risk factors associated with hepatitis C virus (HCV) treatment failure after direct acting antivirals in patients with complex treatment histories. All HCV mono-infected patients who received treatment at our institution were queried. Analysis was restricted to patients who previously failed treatment with boceprevir (BOC) or telaprevir (TVR) and started simeprevir (SMV) and sofosbuvir (SOF) ± ribavirin (RBV) between December 2013 and June 2014. Patients with human immunodeficiency virus (HIV)/HCV co-infection or patients who received a liver transplant in the past were excluded. Viral loads were recorded while on treatment and after treatment. Data collection continued until December, 31(st) 2014 when data analysis was initiated. Patients missing virologic outcomes data were not included in the analysis. Analysis of 35 patients who had virologic outcome data available resulted in eight patients who were viral load negative at the end of treatment with SMF/SOF but later relapsed. Data related to patient demographics, HCV infection, and treatment history was collected in order to identify risk factors shared among patients who failed treatment with SMF/SOF. Eight patients who were treated with the first generation HCV protease inhibitors BOC or TVR in combination with pegylated-interferon (PEG) and RBV who failed this triple therapy were subsequently re-treated with an off-label all-oral regimen of SMV and SOF for 12 wk, with RBV in seven cases. Treatment was initiated before the Food and Drug Administration approved a 24-wk SMV/SOF regimen for patients with liver cirrhosis. All eight patients had an end of treatment response, but later relapsed. Eight (100%) patients were male. Mean age was 56 (range, 49-64). Eight (100%) patients had previously failed PEG/RBV dual therapy at least once in addition to prior failure with triple therapy. Total number of times treated ranged from 3-6 (mean 3.8). Eight (100%) patients were male had liver cirrhosis as determined by Fibroscan or MRI. Seven (87.5%) patients had genotype 1a HCV. Seven (87.5%) patients had over 1 million IU/mL HCV RNA at the time of re-treatment. This study identifies factors associated with SMV/SOF treatment failure and provides evidence that twleve weeks of SMV/SOF/RBV is insufficient in cirrhotics with high-titer genotype 1a HCV.

Hepatitis C Virus Core Protein Modulates Endoglin (CD105) Signaling Pathway for Liver Pathogenesis.

PubMed

Kwon, Young-Chan; Sasaki, Reina; Meyer, Keith; Ray, Ranjit

2017-11-01

Endoglin is part of the TGF-β receptor complex and has a crucial role in fibrogenesis and angiogenesis. It is also an important protein for tumor growth, survival, and cancer cell metastasis. In a previous study, we have shown that hepatitis C virus (HCV) infection induces epithelial-mesenchymal transition (EMT) state and cancer stem-like cell (CSC) properties in human hepatocytes. Our array data suggested that endoglin (CD105) mRNA is significantly upregulated in HCV-associated CSCs. In this study, we have observed increased endoglin expression on the cell surface of an HCV core-expressing hepatocellular carcinoma (HepG2) cell line or immortalized human hepatocytes (IHH) and activation of its downstream signaling molecules. The status of phospho-SMAD1/5 and the expression of inhibitor of DNA binding protein 1 (ID1) were upregulated in HCV-infected cells or viral core gene-transfected cells. Additionally, we observed upregulation of endoglin/ID1 mRNA expression in chronic HCV patient liver biopsy samples. CSC generation by HCV core protein was dependent on the endoglin signaling pathway using activin receptor-like kinase 1 (ALK1) Fc blocking peptide and endoglin small interfering RNA (siRNA). Further, follow-up from in vitro analysis suggested that the antiapoptosis Bcl2 protein, proliferation-related cyclin D1 protein, and CSC-associated Hes1, Notch1, Nanog, and Sox2 proteins are enhanced during infection or ectopic expression of HCV core protein. IMPORTANCE Endoglin plays a crucial role in fibrogenesis and angiogenesis and is an important protein for tumor growth, survival, and cancer cell metastasis. Endoglin enhances ALK1-SMAD1/5 signaling in different cell types, leading to increased proliferation and migration responses. We have observed endoglin expression on the HCV core-expressing cell surface of human hepatocyte origin and activation of phospho-SMAD1/5 and ID1 downstream signaling molecules. ID1 protein plays a role in CSC properties, and we found that this pathway is important for antiapoptotic and cell proliferation signaling. Blocking of endoglin-ALK1-SMAD1/5 might be a good candidate for therapy for liver cancer stem cells together with liver cirrhosis. Copyright © 2017 American Society for Microbiology.

Physician Nonadherence With a Hepatitis C Screening Program

PubMed Central

Southern, William N.; Drainoni, Mari-Lynn; Smith, Bryce D.; Koppelman, Elisa; McKee, M. Diane; Christiansen, Cindy L.; Gifford, Allen L.; Weinbaum, Cindy M.; Litwin, Alain H.

2017-01-01

Background Testing for patients at risk for hepatitis C virus (HCV) infection is recommended, but it is unclear whether providers adhere to testing guidelines. We aimed to measure adherence to an HCV screening protocol during a multifaceted continuous intervention. Subjects and Methods Prospective cohort design to examine the associations between patient-level, physician-level, and visit-level characteristics and adherence to an HCV screening protocol. Study participants included all patients with a visit to 1 of the 3 study clinics and the physicians who cared for them. Adherence to the HCV screening protocol and patient-level, physician-level, and visit-level predictors of adherence were measured. Results A total of 8981 patients and 154 physicians were examined. Overall protocol adherence rate was 36.1%. In multivariate analysis, patient male sex (odds ratio [OR] = 1.18), new patient (OR = 1.23), morning visit (OR = 1.32), and patients’ preferred language being non-English (OR = 0.87) were significantly associated with screening adherence. There was a wide variation in overall adherence among physicians (range, 0%–92.4%). Screening adherence continuously declined from 59.1% in week 1 of the study to 13.7% in week 15 (final week). When implementing complex clinical practice guidelines, planners should address physician attitudinal barriers as well as gaps in knowledge to maximize adherence. PMID:24368717

Maternal hepatitis C (HCV) infection and Anti-D immunoglobulin therapy: study testing antibodies, RNA and Genotype of HCV in Baghdad.

PubMed

Al-Kubaisy, Waqar; Daud, Suzanna; Al-Kubaisi, Mustafa Waseem; Al-Kubaisi, Omar Waseem; Abdullah, Nik Nairan

2018-04-30

Hepatitis C virus (HCV) infection is a serious health problem. It is a major contributor to end-stage liver disease. Worldwide, 1-8% of all pregnant women were infected. Women with viral hepatitis may be at an increased risk of pregnancy complications. There are several obstetrics intervention acts as risk factors, which are specific to women pertaining the HCV infection; anti-D immunoglobulin (Ig) therapy may be one of them. Our objectives were to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. A cross sectional study was conducted. A sample of 154 Rhesus negative (Rh - ve) pregnant women regardless of the anti-D Ig therapy was collected. Anti-HCV were tested using third generation enzyme immunoassay (EIA-3) and immunoblot assay (Lia Tek-111), subsequently. In addition, 89 serum samples were subjected to molecular analysis using RT-PCR and DNA enzyme immunoassay (DEIA) method for the detection of HCV-RNA and genotypes. Anti-HCV, and HCV-RNA seroprevalence were significantly higher (17.1, 35.5%) among women with anti-D Ig than their counter group (6.4, 13.16%), p = .038, .018, respectively. Significant direct positive dose response correlation (r = 0.78, p = .005) had been seen between number of anti-D Ig therapy and anti-HCV seropositive rate. Anti-D Ig therapy act as a risk factor (odds ratio (OR) = 3.01, 95%CI: 1.01-8.9) especially from the third dose onward. Women with anti-D Ig therapy were at higher risk (3.6 times more) of positive HCV-RNA (OR =3.6, 95%CI =1.19-10.837). Genotype HCV-1b showed higher prevalent (52.9%) among the recipients of anti-D Ig therapy while genotype HCV-3a (6.6%) was the lowest. Our study showed that Anti-D immunoglobulin therapy acts as a risk factor for acquiring HCV infection. Screening for HCV should be recommended for all recipients of anti-D Ig. Not only HCV antibodies but HCV-RNA detection being recommended for the diagnosis of HCV infection. A brief rational: Pregnant women with HCV infection are at risk of adverse obstetric outcome. Anti-D Ig therapy may be a risk factor for HCV infection. Hence, we conducted a cross sectional study with the objectives to estimate the prevalence of HCV antibodies (anti-HCV), RNA, and genotype distribution among women with anti-D Ig therapy. We found that anti-HCV and HCV-RNA seroprevalence were significantly higher in women with anti-D Ig. In addition, women with anti-D Ig therapy were 3.6 times more at risk of positive HCV-RNA with genotype HCV-1b showed higher prevalence. Therefore, anti-D Ig therapy is a risk factor for acquiring HCV infection and we recommend screening for HCV for all recipients of anti-D Ig. In addition, the diagnosis of HCV infection, should be made with HCV antibodies and HCV-RNA detection.

Infectious Aetiology of Marginal Zone Lymphoma and Role of Anti-Infective Therapy

PubMed Central

Perrone, Salvatore; D’Elia, Gianna Maria; Annechini, Giorgia; Pulsoni, Alessandro

2016-01-01

Marginal zone lymphomas have been associated with several infectious agents covering both viral and bacterial pathogens and in some cases a clear aetiological role has been established. Pathogenetic mechanisms are currently not completely understood. However, the role of chronic stimulation of the host immune response with persistent lymphocyte activation represents the most convincing explanation for lymphoproliferation. Gastric MALT lymphoma is strictly associated with Helicobacter pylori infection and various eradicating protocols, developed due to increasing antibiotic resistance, represent the first line therapy for gastric MALT. The response rate to eradication is good with 80% of response at 1 year; this finding is also noteworthy because it recapitulates cancer cured only by the antibacterial approach and it satisfies the Koch postulates of causation, establishing a causative relationship between Hp and gastric MALT lymphoma. Patients with chronic HCV infection have 5 times higher risk to develop MZL, in particular, an association with splenic and nodal MZL has been shown in several studies. Moreover, there is evidence of lymphoma regression after antiviral therapy with interferon+ribavirin, thus raising hope that newly available drugs, extremely efficient against HCV replication, could improve outcome also in HCV-driven lymphomas. Another case-study are represented by those rare cases of MZL localized to orbital fat and eye conjunctivas that have been associated with Chlamydophila psittaci infection carried by birds. Efficacy of antibacterial therapy against C. psittaci are conflicting and generally poorer than gastric MALT. Finally, some case reports will cover the relationship between primary cutaneous B-cell Lymphomas and Borrelia Burgdorferi. PMID:26740867

Clinical relevance of total HCV core antigen testing for hepatitis C monitoring and for predicting patients' response to therapy.

PubMed

Maynard, M; Pradat, P; Berthillon, P; Picchio, G; Voirin, N; Martinot, M; Marcellin, P; Trepo, C

2003-07-01

To study the correlation between total Hepatitis C virus (HCV) Core antigen (Ag) and HCV-RNA, and to assess the proficiency of HCV Core Ag testing in monitoring and predicting virologic response during and after pegylated interferon (PEG-IFN) and ribavirin combination therapy. A total of 307 samples from treated and untreated patients were used to assess the correlation between the total HCV Core Ag test and quantitative HCV-RNA assays (Superquant, and Quantiplex branched DNA 2.0 assay). Twenty-four patients received combination therapy for 48 weeks. Blood samples were collected at day 0, and week 2, 4, 12, 24, 48 and 72 for virologic evaluation. A linear relation exists between total HCV Core Ag and HCV-RNA levels. At 3 months the positive predictive value (PPV) of response to therapy was 100% with either HCV Core Ag or HCV-RNA. For HCV Core Ag the negative predictive value (NPV) was 100% whereas for HCV-RNA the NPV was 80% (P > 0.05). At month 1, the PPV was 95% and 100% when determined by HCV Core Ag and HCV-RNA, respectively. The NPV value was 100% for HCV Core Ag and 33% for HCV-RNA (P = 0.005). HCV Core Ag quantification could be useful in clinical practice to predict a sustained virological response early during therapy (4 weeks), reaching an optimal performance at month 3. The determination of total HCV Core Ag levels in serum, constitutes an accurate and reliable alternative to HCV-RNA for monitoring and predicting treatment outcome in patients receiving PEG-IFN/Ribavirin combination therapy.

Travel-associated acquisition of hepatitis C virus infection in patients receiving haemodialysis.

PubMed

Ghafur, Abdul; Raza, Muhammad; Labbett, Wendy; Chawla, Anuradha; Smith, Colette; Ngui, Siew Lin; Davenport, Andrew; Geretti, Anna Maria

2007-09-01

It has been proposed that hepatitis C virus (HCV)-infected patients with end-stage renal disease undergoing maintenance haemodialysis may lack HCV antibody (anti-HCV) despite chronic HCV viraemia. This carries important implications for the design of surveillance policies. To characterize the prevalence of antibody-negative/RNA-positive HCV infection, patients attending seven haemodialysis units underwent anti-HCV testing using a third-generation assay and HCV RNA testing using real-time PCR. At screening, anti-HCV prevalence was 12/360 (3.3%; 95% CI 1.7-5.8%); 7/12 (58.3%) anti-HCV positive samples were HCV RNA positive. Among anti-HCV-negative samples, 2/348 (0.6%; 95% CI 0.2-2.1%) tested HCV RNA positive (genotype 1a). Retrospective testing of stored sera dated the infections to a period of holiday in the Indian subcontinent. The two infections were unrelated by HCV-NS5B sequencing. Only one of the two newly infected persons showed raised transaminases. Both developed anti-HCV within 8-13 weeks of follow-up. Prospective surveillance of travellers to resource-limited countries returning to the units showed a HCV incidence of 4/153 travel episodes (2.6%; 95% CI 0.7-6.6%) among 131 persons (3.1%; 95% CI 0.8-7.6%). Among haemodialysis patients in the United Kingdom, antibody-negative/RNA-positive HCV status is associated with newly acquired infection, rather than lack of antibody responses in chronic HCV infection. There is a significant risk of HCV infection associated with travel to resource-limited countries. Given that transaminase levels may be normal, HCV RNA testing is recommended in patients re-entering a dialysis unit following haemodialysis in settings where suboptimal infection control policies pose a risk of exposure to blood-borne viruses.

Fast hepatitis C virus RNA elimination and NS5A redistribution by NS5A inhibitors studied by a multiplex assay approach.

PubMed

Liu, Dandan; Ji, Juan; Ndongwe, Tanya P; Michailidis, Eleftherios; Rice, Charles M; Ralston, Robert; Sarafianos, Stefan G

2015-01-01

While earlier therapeutic strategies for the treatment of hepatitis C virus (HCV) infection relied exclusively on interferon (IFN) and ribavirin (RBV), four direct-acting antiviral agents (DAAs) have now been approved, aiming for an interferon-free strategy with a short treatment duration and fewer side effects. To facilitate studies on the mechanism of action (MOA) and efficacy of DAAs, we established a multiplex assay approach, which employs flow cytometry, a Gaussia luciferase reporter system, Western blot analysis, reverse transcription-quantitative PCR (RT-qPCR), a limited dilution assay (50% tissue culture infectious dose [TCID50]), and an image profiling assay that follows the NS5A redistribution in response to drug treatment. We used this approach to compare the relative potency of various DAAs and the kinetics of their antiviral effects as a potential preclinical measure of their potential clinical utility. We evaluated the NS5A inhibitors ledipasvir (LDV) and daclatasvir (DCV), the NS3/4A inhibitor danoprevir (DNV), and the NS5B inhibitor sofosbuvir (SOF). In terms of kinetics, our data demonstrate that the NS5A inhibitor LDV, followed closely by DCV, has the fastest effect on suppression of viral proteins and RNA and on redistribution of NS5A. In terms of MOA, LDV has a more pronounced effect than DCV on the viral replication, assembly, and infectivity of released virus. Our approach can be used to facilitate the study of the biological processes involved in HCV replication and help identify optimal drug combinations. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Insight into the recognition, binding, and reactivity of catalytic metallodrugs targeting stem loop IIb of hepatitis C IRES RNA.

PubMed

Bradford, Seth S; Ross, Martin James; Fidai, Insiya; Cowan, James A

2014-06-01

The complex Cu-GGHYrFK-amide (1-Cu) was previously reported as a novel metallotherapeutic that catalytically inactivates stem loop IIb (SLIIb) of the hepatitis C virus (HCV) internal ribosomal entry site (IRES) RNA and demonstrates significant antiviral activity in a cellular HCV replicon assay. Herein we describe additional studies focused on understanding the cleavage mechanism as well as the relationship of catalyst configuration to structural recognition and site-selective cleavage of the structured RNA motif. These are advanced by use of a combination of MALDI-TOF mass spectrometry, melting temperature determinations, and computational analysis to develop a structural model for binding and reactivity toward SLIIb of the IRES RNA. In addition, the binding, reactivity, and structural chemistry of the all-D-amino acid form of this metallopeptide, complex 2-Cu, are reported and compared with those of complex 1-Cu. In vitro RNA binding and cleavage assays for complex 2-Cu show a KD value of 76 ± 3 nM, and Michaelis-Menten parameters of kcat =0.14 ± 0.01 min(-1) and KM =7.9 ± 1.2 μM, with a turnover number exceeding 40. In a luciferase-based cellular replicon assay Cu-GGhyrfk-amide shows activity similar to that of the 1-Cu parent peptide, with an IC50 value of 1.9 ± 0.4 μM and cytotoxicity exceeding 100 μM. RT-PCR experiments confirm a significant decrease in HCV RNA levels in replicon assays for up to nine days when treated with complex 1-Cu in three-day dosing increments. This study shows the influence that the α-carbon stereocenter has for this new class of compounds, while detailed mass spectrometry and computational analyses provide new insight into the mechanisms of recognition, binding, and reactivity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

New perspectives in occult hepatitis C virus infection

PubMed Central

Carreño, Vicente; Bartolomé, Javier; Castillo, Inmaculada; Quiroga, Juan Antonio

2012-01-01

Occult hepatitis C virus (HCV) infection, defined as the presence of HCV RNA in liver and in peripheral blood mononuclear cells (PBMCs) in the absence of detectable viral RNA in serum by standard assays, can be found in anti-HCV positive patients with normal serum levels of liver enzymes and in anti-HCV negative patients with persistently elevated liver enzymes of unknown etiology. Occult HCV infection is distributed worldwide and all HCV genotypes seem to be involved in this infection. Occult hepatitis C has been found not only in anti-HCV positive subjects with normal values of liver enzymes or in chronic hepatitis of unknown origin but also in several groups at risk for HCV infection such as hemodialysis patients or family members of patients with occult HCV. This occult infection has been reported also in healthy populations without evidence of liver disease. Occult HCV infection seems to be less aggressive than chronic hepatitis C although patients affected by occult HCV may develop liver cirrhosis and even hepatocellular carcinoma. Thus, anti-HCV negative patients with occult HCV may benefit from antiviral therapy with pegylated-interferon plus ribavirin. The persistence of very low levels of HCV RNA in serum and in PBMCs, along with the maintenance of specific T-cell responses against HCV-antigens observed during a long-term follow-up of patients with occult hepatitis C, indicate that occult HCV is a persistent infection that is not spontaneously eradicated. This is an updated report on diagnosis, epidemiology and clinical implications of occult HCV with special emphasis on anti-HCV negative cases. PMID:22736911

An apparent lack of epidemiologic association between hepatitis C virus knowledge and the prevalence of hepatitis C infection in a national survey in Egypt.

PubMed

Chemaitelly, Hiam; Abu-Raddad, Laith J; Miller, F DeWolfe

2013-01-01

Egypt has by far the largest hepatitis C virus (HCV) prevalence in the world with 14.7% of the population being antibody positive for HCV. The aim of this study was to examine the association between knowledge of HCV and HCV antibody positivity among the Egyptian population. We characterized different measures of HCV knowledge and examined their associations with HCV prevalence, by analyzing a nationally representative database using standard epidemiologic methods. The database, the 2008 Egyptian Demographic and Health Survey, included demographic, health, and HCV biomarker information for a sample of over 12,000 individuals. Basic knowledge of HCV was found to be high, but multiple gaps were identified in the specific knowledge of HCV and its modes of transmission. There was no statistically significant difference in HCV prevalence between those who have heard of HCV infection and those who have not (14.4% vs. 15.9%, p>.05). Similar results were found for the other HCV knowledge measures including those specific to HCV modes of transmission and to the sources of information for HCV awareness. Logistic regression analyses did not demonstrate an association between HCV knowledge and HCV prevalence. Our results do not provide support for an effect of awareness on reducing the risk of HCV infection in Egypt. Public health messages directed at the lay public may not provide sufficient empowerment for individuals to avoid HCV infection, and should be complemented with prevention programs to promote and strengthen infection control in the settings of exposure, particularly in health care facilities.

High burden of HCV disease and poor access to HCV services among people who inject drugs in India: A cross-sectional study among 14,481 drug users across India

PubMed Central

Solomon, Sunil Suhas; Mehta, Shruti H; Srikrishnan, Aylur K; Solomon, Suniti; McFall, Allison M.; Laeyendecker, Oliver; Celentano, David D; Iqbal, Syed H; Anand, Santhanam; Vasudevan, Canjeevaram K; Saravanan, Shanmugam; Lucas, Gregory M; Kumar, Muniratnam S; Sulkowski, Mark S; Quinn, Thomas C

2014-01-01

Background Globally, 90% of HCV-infected individuals reside in resource-limited settings (RLS). We characterized the prevalence of HCV, HIV/HCV co-infection, and the HCV care continuum among people who inject drugs (PWID) in India. Methods 14,481 PWID were sampled from 15 cities throughout India using respondent-driven sampling (RDS) from January–December 2013. HCV prevalence was estimated by the presence of anti-HCV antibodies incorporating RDS weights. HCV care continuum outcomes were self-reported except for viral clearance among treatment-experienced participants. Findings Median age was 30 years and 13,608/14,449 (92·4%) were male. Overall weighted HCV prevalence was 37·2% (5,777/14,447); HIV/HCV co-infection prevalence was 13·2% (2,085/14,435). Correlates of HCV infection included higher lifetime injection frequency, HIV positivity, and a higher prevalence of persons with HIV RNA > 1000 copies/ml in the community. Of 5,777 HCV antibody positive PWID, 440 (5·5%) were aware of their status, 225 (3·0%) had seen a doctor for their HCV, 79 (1·4%) had taken HCV treatment, and 18 (0·4%) had undetectable HCV RNA. Overall, 6,138/12,128 (50·5%) did not get tested for HCV because they had never heard of HCV. Among the 5,777 HCV antibody positives, 2,086 (34·4%) reported harmful/hazardous alcohol use of whom 1,082 (50·4%) were dependent; 3,007 (52.9%) reported recent needle sharing. Awareness of HCV positive status was significantly associated with higher education, HIV testing history, awareness of HIV positive status, and higher community antiretroviral therapy coverage. Interpretation The high burden of HCV and HIV/HCV co-infection coupled with low-access to HCV services highlights an urgent need to include RLS in the global HCV agenda. While newer treatments will become available globally in the near future, programs to improve awareness, and reduce disease progression and transmission need to be scaled-up without further delay. Failure to do so could result in patterns of rising mortality, undermining advances in survival attributed to widespread HIV treatment. Funding US National Institutes of Health PMID:25486851

Cost-Effectiveness of Access Expansion to Treatment of Hepatitis C Virus Infection Through Primary Care Providers.

PubMed

Rattay, Thilo; Dumont, Ian P; Heinzow, Hauke S; Hutton, David W

2017-12-01

Chronic hepatitis C virus (HCV) infection is a major burden on individuals and health care systems. The Extension for Community Healthcare Outcomes (Project ECHO) enables primary care providers to deliver best-practice care for complex conditions to underserved populations. The US Congress passed the ECHO Act in late 2016, requiring the Department of Health and Human Services to investigate the model. We performed a cost-effectiveness analysis to assess diagnosis and treatment of HCV infection in a primary care patient panel with and without the implementation of Project ECHO. We used Markov models to simulate disease progression, quality of life, and life expectancy among individuals with HCV infection and for the general population. Data from the University of New Mexico's ECHO operation for HCV show an increase in treatment rates. Corresponding increases in survival, quality-adjusted life years (QALYs), costs, and resulting budget impact between ECHO and non-ECHO patients with HCV were then compared. Project ECHO increased costs and QALYs. The incremental cost-effectiveness ratio of ECHO was $10,351 per QALY compared with the status quo; >99.9% of iterations fell below the willingness-to-pay threshold of $100,000 per QALY. We were unable to confirm whether the increase in rates of treatment associated with Project ECHO were due to increased or more targeted screening, higher adherence, or access to treatment. Our sensitivity analyses show that the results are largely independent of the cause. Budget impact analysis shows payers would have to invest an additional $339.54 million over a 5-year period to increase treatment by 4446 patients, per 1 million covered lives. Using a simulated primary care patient panel, we showed that Project ECHO is a cost-effective way to find and treat patients with HCV infection at scale using existing primary care providers. This approach could substantially reduce the burden of chronic HCV infection in the United States, but high budgetary costs suggest that incremental rollout of ECHO may be best. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Biomarker Discovery for Early Detection of Hepatocellular Carcinoma in Hepatitis C–infected Patients*

PubMed Central

Mustafa, Mehnaz G.; Petersen, John R.; Ju, Hyunsu; Cicalese, Luca; Snyder, Ned; Haidacher, Sigmund J.; Denner, Larry; Elferink, Cornelis

2013-01-01

Chronic hepatic disease damages the liver, and the resulting wound-healing process leads to liver fibrosis and the subsequent development of cirrhosis. The leading cause of hepatic fibrosis and cirrhosis is infection with hepatitis C virus (HCV), and of the patients with HCV-induced cirrhosis, 2% to 5% develop hepatocellular carcinoma (HCC), with a survival rate of 7%. HCC is one of the leading causes of cancer-related death worldwide, and the poor survival rate is largely due to late-stage diagnosis, which makes successful intervention difficult, if not impossible. The lack of sensitive and specific diagnostic tools and the urgent need for early-stage diagnosis prompted us to discover new candidate biomarkers for HCV and HCC. We used aptamer-based fractionation technology to reduce serum complexity, differentially labeled samples (six HCV and six HCC) with fluorescent dyes, and resolved proteins in pairwise two-dimensional difference gel electrophoresis. DeCyder software was used to identify differentially expressed proteins and spots picked, and MALDI-MS/MS was used to determine that ApoA1 was down-regulated by 22% (p < 0.004) in HCC relative to HCV. Differential expression quantified via two-dimensional difference gel electrophoresis was confirmed by means of 18O/16O stable isotope differential labeling with LC-MS/MS zoom scans. Technically independent confirmation was demonstrated by triple quadrupole LC-MS/MS selected reaction monitoring (SRM) assays with three peptides specific to human ApoA1 (DLATVYVDVLK, WQEEMELYR, and VSFLSALEEYTK) using 18O/16O-labeled samples and further verified with AQUA peptides as internal standards for quantification. In 50 patient samples (24 HCV and 26 HCC), all three SRM assays yielded highly similar differential expression of ApoA1 in HCC and HCV patients. These results validated the SRM assays, which were independently confirmed by Western blotting. Thus, ApoA1 is a candidate member of an SRM biomarker panel for early diagnosis, prognosis, and monitoring of HCC. Future multiplexing of SRM assays for other candidate biomarkers is envisioned to develop a biomarker panel for subsequent verification and validation studies. PMID:24008390

Hepatitis C virus infection is an independent prognostic factor in follicular lymphoma

PubMed Central

Shimono, Joji; Miyoshi, Hiroaki; Kato, Takeharu; Sugio, Takeshi; Miyawaki, Kohta; Kamimura, Tomohiko; Miyagishima, Takuto; Eto, Tetsuya; Imaizumi, Yoshitaka; Kato, Koji; Nagafuji, Koji; Akashi, Koichi; Seto, Masao; Teshima, Takanori; Ohshima, Koichi

2018-01-01

Hepatitis C virus (HCV) is a single-stranded RNA virus that not only affects hepatocytes, by B cells as well. It is thought that HCV is involved in the onset of B-cell lymphoma. The clinicopathological characteristics of HCV-positive diffuse large B-cell lymphoma (DLBCL) and HCV-positive splenic marginal zone lymphoma (SMZL) are known, but there has been no report on HCV-positive follicular lymphoma (FL). In this study, the clinicopathological characteristics of HCV-positive FL were examined in 263 patients with FL who were classified into a HCV-positive group with HCV antibody and negative groups without one. The number of patients with HCV-positive FL and HCV-negative FL was 10 (3.8%) and 253 (96.2%), respectively. The patients with HCV-positive FL commonly had more than one region of lymphadenopathy, Ann Arbor stage III/IV, hemoglobin <120 g/l, elevated lactate dehydrogenase level, and high-risk categorization of Follicular Lymphoma International Prognostic Index (FLIPI) than in patients with HCV-negative FL. Overall survival and progression-free survival were poorer in patients with HCV-positive FL than in those with HCV-negative FL (p < 0.0001 and 0.006, respectively). Also, multivariate analysis revealed that positive HCV antibody was a poor prognostic factor of OS. In conclusion, HCV-positive FL has unique clinical features and may have a great impact on the overall survival of affected patients. PMID:29416725

Hepatitis C virus infection is an independent prognostic factor in follicular lymphoma.

PubMed

Shimono, Joji; Miyoshi, Hiroaki; Kato, Takeharu; Sugio, Takeshi; Miyawaki, Kohta; Kamimura, Tomohiko; Miyagishima, Takuto; Eto, Tetsuya; Imaizumi, Yoshitaka; Kato, Koji; Nagafuji, Koji; Akashi, Koichi; Seto, Masao; Teshima, Takanori; Ohshima, Koichi

2018-01-05

Hepatitis C virus (HCV) is a single-stranded RNA virus that not only affects hepatocytes, by B cells as well. It is thought that HCV is involved in the onset of B-cell lymphoma. The clinicopathological characteristics of HCV-positive diffuse large B-cell lymphoma (DLBCL) and HCV-positive splenic marginal zone lymphoma (SMZL) are known, but there has been no report on HCV-positive follicular lymphoma (FL). In this study, the clinicopathological characteristics of HCV-positive FL were examined in 263 patients with FL who were classified into a HCV-positive group with HCV antibody and negative groups without one. The number of patients with HCV-positive FL and HCV-negative FL was 10 (3.8%) and 253 (96.2%), respectively. The patients with HCV-positive FL commonly had more than one region of lymphadenopathy, Ann Arbor stage III/IV, hemoglobin <120 g/l, elevated lactate dehydrogenase level, and high-risk categorization of Follicular Lymphoma International Prognostic Index (FLIPI) than in patients with HCV-negative FL. Overall survival and progression-free survival were poorer in patients with HCV-positive FL than in those with HCV-negative FL ( p < 0.0001 and 0.006, respectively). Also, multivariate analysis revealed that positive HCV antibody was a poor prognostic factor of OS. In conclusion, HCV-positive FL has unique clinical features and may have a great impact on the overall survival of affected patients.

HIV, HBV, and HCV molecular epidemiology among trans (transvestites, transsexuals, and transgender) sex workers in Argentina.

PubMed

Carobene, Mauricio; Bolcic, Federico; Farías, María Sol Dos Ramos; Quarleri, Jorge; Avila, María Mercedes

2014-01-01

Commercial sex work is frequent among male-to-female transvestites, transsexuals and transgenders in Argentina, leading to high susceptibility to HIV, HBV, and HCV among other sexually transmitted infections. In a global context of scarce data on the trans sex workers population, this study was aimed to study the genomic characterization of these viruses. Plasma presence of HIV, HBV, and HCV genomic material was evaluated in samples from 273 trans sex workers. Genomic sequences of HIV-gag, pol, and vif-vpu genes, HBV-S gene, and HCV-5'UT and NS5B genes were obtained. Molecular characterization involved phylogenetic analysis and several in silico tools. Resistance-associated mutations in HIV and HBV pol genes were also analyzed. The HIV genomic characterization in 62 trans sex workers samples showed that 54.8% of the isolates corresponded to BF intersubtype recombinants, and 38.7% to subtype B. The remaining were classified as subtypes C (4.8%) and A (1.6%). HBV and HCV co-infection prevalence among HIV positive trans sex workers yielded rates of 3.2% and 6.5% respectively. Drug resistance-associated mutations were found in 12/62 (19%) HIV pol sequences, but none among HBV. Based on phylogenetic relationships, HIV isolates characterized as subtypes BF and B appeared intermingled with those from other high-risk groups. Despite trans sex workers declared not to have received antiviral treatment, complex drug resistance-associated mutation patterns were found in several HIV isolates. Planned prevention, screening, and treatment are needed to reduce further transmission and morbidity. © 2013 Wiley Periodicals, Inc.

Genetic basis for variation in plasma IL-18 levels in persons with chronic hepatitis C virus and human immunodeficiency virus-1 infections.

PubMed

Vergara, C; Thio, C; Latanich, R; Cox, A L; Kirk, G D; Mehta, S H; Busch, M; Murphy, E L; Villacres, M C; Peters, M G; French, A L; Golub, E; Eron, J; Lahiri, C D; Shrestha, S; Gustafson, D; Young, M; Anastos, K; Aouizerat, B; Kim, A Y; Lauer, G; Thomas, D L; Duggal, P

2017-03-01

Inflammasomes are multi-protein complexes integrating pathogen-triggered signaling leading to the generation of pro-inflammatory cytokines including interleukin-18 (IL-18). Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections are associated with elevated IL-18, suggesting inflammasome activation. However, there is marked person-to-person variation in the inflammasome response to HCV and HIV. We hypothesized that host genetics may explain this variation. To test this, we analyzed the associations of plasma IL-18 levels and polymorphisms in 10 genes in the inflammasome cascade. About 1538 participants with active HIV and/or HCV infection in three ancestry groups are included. Samples were genotyped using the Illumina Omni 1-quad and Omni 2.5 arrays. Linear regression analyses were performed to test the association of variants with log IL-18 including HCV and HIV infection status, and HIV RNA in each ancestry group and then meta-analyzed. Eleven highly correlated single-nucleotide polymorphisms (r 2 =0.98-1) in the IL-18-BCO2 region were significantly associated with log IL-18; each T allele of rs80011693 confers a decrease of 0.06 log pg ml -1 of IL-18 after adjusting for covariates (rs80011693; rs111311302 β=-0.06, P-value=2.7 × 10 -4 ). In conclusion, genetic variation in IL-18 is associated with IL-18 production in response to HIV and HCV infection, and may explain variability in the inflammatory outcomes of chronic viral infections.

Genetic basis for variation in plasma IL-18 levels in persons with chronic hepatitis C virus and human immunodeficiency virus-1 infections

PubMed Central

Vergara, Candelaria; Thio, Chloe; Latanich, Rachel; Cox, Andrea L.; Kirk, Gregory D.; Mehta, Shruti H.; Busch, Michael; Murphy, Edward L; Villacres, Maria C.; Peters, Marion G.; French, Audrey L.; Golub, Elizabeth; Eron, Joseph; Lahiri, Cecile Delille; Shrestha, Sadeep; Gustafson, Deborah; Young, Mary; Anastos, Kathryn; Aouizerat, Bradley; Kim, Arthur Y.; Lauer, Georg; Thomas, David L.; Duggal, Priya

2016-01-01

Inflammasomes are multi-protein complexes integrating pathogen-triggered signaling leading to the generation of pro-inflammatory cytokines, including interleukin-18 (IL-18). Hepatitis C virus (HCV) and human immunodeficiency virus-1 (HIV) infections are associated with elevated IL-18, suggesting inflammasome activation. However, there is marked person-to-person variation in the inflammasome response to HCV and HIV. We hypothesized that host genetics may explain this variation. To test this, we analyzed the associations of plasma IL-18 levels and polymorphisms in 10 genes in the inflammasome cascade. 1538 participants with active HIV and/or HCV infection in 3 ancestry groups are included. Samples were genotyped using the Illumina Omni 1-quad and Omni 2.5 arrays. Linear regression analyses were performed to test the association of variants with logIL-18 including HCV and HIV infection status and HIV-RNA, in each ancestry group and then meta-analyzed. Eleven highly correlated SNPs (r2=0.98-1) in the IL18-BCO2 region were significantly associated with logIL-18; Each T allele of rs80011693 confers a decrease of 0.06 log pg/mL of IL-18 after adjusting for covariates (rs80011693; rs111311302 β=-0.06, P-value=2.7×10-4). In conclusion, genetic variation in IL18 is associated with IL-18 production in response to HIV and HCV infection and may explain variability in the inflammatory outcomes of chronic viral infections. PMID:28300059

HCV core-antigen assay as an alternative to HCV RNA quantification: A correlation study for the assessment of HCV viremia.

PubMed

Alonso, Roberto; Pérez-García, Felipe; López-Roa, Paula; Alcalá, Luis; Rodeño, Pilar; Bouza, Emilio

2018-03-01

Detection of hepatitis C virus (HCV) RNA and the HCV core antigen assay (HCV-Ag) are reliable techniques for the diagnosis of active and chronic HCV infection. Our aim was to evaluate the HCV-Ag assay as an alternative to quantification of HVC RNA. A comparison was made of the sensitivity and specificity of an HCV-Ag assay (204 serum samples) with those of a PCR assay, and the correlation between the two techniques was determined. The sensitivity and specificity of HCV-Ag was 76.6% and 100%, respectively. Both assays were extremely well correlated (Pearson coefficient=0.951). The formula (LogCV=1.15*LogAg+2.26) was obtained to calculate the viral load by PCR from HCV-Ag values. HCV-Ag was unable to detect viral loads below 5000IU/mL. Although the HCV-Ag assay was less sensitive than the PCR assay, the correlation between both assays was excellent. HCV-Ag can be useful as a first step in the diagnosis of acute or chronic HCV infection and in emergency situations. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Evaluation of the Impact of Mandating Health Care Providers to Offer Hepatitis C Virus Screening to All Persons Born During 1945-1965 - New York, 2014.

PubMed

Flanigan, Colleen A; Leung, Shu-Yin J; Rowe, Kirsten A; Levey, Wendy K; King, Andrea; Sommer, Jamie N; Morne, Johanne E; Zucker, Howard A

2017-09-29

Approximately 75% of all hepatitis C virus (HCV) infections in the United States and 73% of HCV-associated mortality occur in persons born during 1945-1965, placing this birth cohort at increased risk for liver cancer and other HCV-related liver disease (1). In the United States, an estimated 2.7 million persons are living with HCV infection, and it is estimated that up to 75% of these persons do not know their status. Since 2012, CDC has recommended that persons born during 1945-1965 receive one-time HCV testing. To increase the number of persons tested for HCV and to ensure timely diagnosis and linkage to care, in 2014, New York enacted a hepatitis C testing law that requires health care providers to offer HCV antibody screening to all persons born during 1945-1965 who are receiving services in primary care settings or as hospital inpatients, and to refer persons with positive HCV antibody tests for follow-up health care, including an HCV diagnostic test (i.e., HCV RNA).* The New York State Department of Health (NYSDOH) used survey data from clinical laboratories and Medicaid claims and encounter data, and state and New York City (NYC) HCV surveillance data to assess the number of persons tested for HCV and number of persons with newly diagnosed HCV infections who were linked to care. During the first year of the HCV law implementation, there was a 51% increase in specimens submitted for HCV testing to surveyed clinical laboratories; testing rates among active Medicaid clients increased 52%, and linkage to care among persons with newly diagnosed HCV infection increased approximately 40% in New York and 11% in NYC. These findings highlight the potential for state laws to promote HCV testing and the utility of HCV surveillance and Medicaid claims data to monitor the quality of HCV testing and linkage to care for HCV-infected persons.

Consensus statement on the management of patients with HCV infection in Romania

PubMed Central

Ancuța, Ioan

2017-01-01

Background HCV direct-acting antivirals (DAAs) have made treatment easier for both patients and healthcare practitioners, but have also brought new challenges in terms of patient management and monitoring prior to, during, and after treatment. Methods To sum up and unify the clinical experience of Romanian DAA prescribing physicians, we have organized a Consensus Meeting in November 2016 in Bucharest, Romania. Consensus Statement The Consensus Meeting has provided expert answers to ten significant questions regarding HCV infection, namely: How do we diagnose patients with HCV infection? How do we stage liver disease in patients with HCV infection? How do we monitor patients with HCV infection prior to treatment? Which patients with HCV infection do we treat? When do we start treatment for HCV infection? What regimens do we use for treating HCV infection? How do we monitor patients with HCV infection during treatment? What adverse events should we expect during treatment of HCV infection and how do we prevent/manage them? How do we monitor patients with HCV infection after treatment? How do we expect the landscape of HCV to change in the following years? PMID:28331840

Co-infection by hepatitis B virus and hepatitis C virus in renal transplantation: morbidity and mortality in 1098 patients.

PubMed

Pouteil-Noble, C; Tardy, J C; Chossegros, P; Mion, F; Chevallier, M; Gérard, F; Chevallier, P; Megas, F; Lefrançois, N; Touraine, J L

1995-01-01

The aim of the study was to analyse the influence of co-infection by hepatitis B virus (HBV) and hepatitis C virus (HCV) as compared with HCV infection alone in 1098 patients who received a kidney transplant between 1 January and 31 December 1991. At transplantation, the prevalence of anti-HCV antibodies was 21.40% (235/1098) while the prevalence of HBV infection was 9.85% (108/1096); 46 patients were co-infected with HBV and HCV, either 19.70% of HCV-infected patients and 42.60% of HBV-infected patients. Liver tests, galactose clearance and liver biopsy were compared in the 46 co-infected patients (HCV+HBV+) and in the 189 HCV-infected patients (HCV+HBV-). At the time of transplantation, cytolysis was present in 31.45% of HCV+HBV- patients (50/159) and in 40% of HCV+HBV- patients (16/40); cholestasis was present in 34.18% of HCV+HBV- patients (34/158) and 42.11% of HCV+HBV+ patients (16/38). At 6 months the incidence of biological abnormalities increased to 37% in HCV+HBV- patients (55/150) and to 52.5% in HCV+HBV+ patients (21/40), suggesting a more deleterious effect of the immunosuppressive therapy in the co-infected group. Over the course of transplantation, chronic hepatitis was present in 50% of HCV+HBV- patients and in 64.1% of HCV+HBV+ patients. Liver failure occurred in 7% of HCV+HBV- patients (12/156) and 17% of HCV+HBV+ patients (7/41). Galactose clearance was performed as a functional test in 68 patients: it was not significantly different in either group. Liver biopsy was performed in 108 patients at least once.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C virus infection and spontaneous clearance in HTLV-1 and HIV co-infected patients in Salvador, Bahia, Brazil

PubMed Central

Le Marchand, Chloe; Bahia, Fabianna; Page, Kimberly; Brites, Carlos

2015-01-01

Background While 20–40% of patients with hepatitis C virus (HCV) monoinfection will spontaneously clear the virus, less is known regarding clearance with coinfections. HCV, human immunodeficiency virus (HIV), and human T-cell lymphotrophic virus 1 and 2 (HTLV-1/2) coinfection occurs due to shared routes of transmission and is prevalent in Brazil. Objectives To compare the proportion of patients who have spontaneously cleared HCV in patients with HCV monoinfection to patients coinfected by HCV/HIV, or HCV/HIV/HTLV-1. Methods Using medical records from two clinics in Salvador, Brazil, including demographic data and serological markers of HCV, HIV and HTLV-I/II, cross-sectional data was obtained from 197 patients. Patients who were anti-HCV positive and HCV RNA negative, and who did not receive HCV treatment were defined as having cleared infection. Results Nineteen patients (9.5%) showed evidence of spontaneous HCV clearance; with clearance in 9 of 108 (8.3%) patients in the HCV monoinfected group, 5 of 68 (7.4%) patients with HCV/HIV, and 5 of 21 (23.8%) patients with HCV/HIV/HTLV. Demographic data were not associated with HCV clearance status. Patients coinfected with both HIV and HTLV-1 had increased odds (5.50; 95% CI 1.00, 30.17) of spontaneous clearance of HCV compared with patients who were HIV negative or of unknown HIV status. Conclusion Our study found that patients coinfected with HIV and HTLV-1 were more likely to spontaneously clear hepatitis C virus than patients with HIV/HCV or HCV alone. The effects of HTLV coinfection on the immune response of such patients may be associated with these findings. PMID:26254690

Comprehensive longitudinal analysis of hepatitis C virus (HCV)-specific T cell responses during acute HCV infection in the presence of existing HIV-1 infection.

PubMed

van den Berg, C H S B; Ruys, T A; Nanlohy, N M; Geerlings, S E; van der Meer, J T; Mulder, J-W; Lange, J A; van Baarle, D

2009-04-01

The aim of this study was to study the development of HCV-specific T cell immunity during acute HCV infection in the presence of an existing HIV-1 infection in four HIV-1 infected men having sex with men. A comprehensive analysis of HCV-specific T cell responses was performed at two time points during acute HCV infection using a T cell expansion assay with overlapping peptide pools spanning the entire HCV genome Three patients with (near) normal CD4+ T cell counts (range 400-970 x 10(6)/L) either resolved (n=1) or temporary suppressed HCV RNA. In contrast, one patient with low CD4+ T cell counts (330 x 10(6)/L), had sustained high HCV RNA levels. All four patients had low HCV-specific CD8+ T cell responses, and similar magnitudes of CD4+ T cell responses. Interestingly, individuals with resolved infection or temporary suppression of HCV-RNA had HCV-specific CD4+ T cell responses predominantly against nonstructural (NS) proteins. While the individual with high HCV RNA plasma concentrations had CD4+ T cell responses predominantly directed against Core. Our data show that an acute HCV infection in an HIV-1 infected person can be suppressed in the presence of HCV-specific CD4+ T cell response targeting non-structural proteins. However further research is needed in a larger group of patients to evaluate the role of HIV-1 on HCV-specific T cell responses in relation to outcome of acute HCV infection.

Diagnosis and monitoring of HCV infection using the cobas® HCV test for use on the cobas® 6800/8800 systems.

PubMed

Yao, Joseph D; Young, Stephen; Heilek, Gabrielle M; Marino, Enrique; Paxinos, Ellen E; Marins, Ed G; Valsamakis, Alexandra

2018-05-01

Accurate, sensitive, and specific tests for detection and monitoring of hepatitis C virus (HCV) RNA concentrations are essential for diagnosis and management of HCV infections. We evaluated the next-generation reverse-transcription real-time PCR test, cobas ® HCV test for use with the cobas ® 6800/8800 systems ("cobas HCV") by determining its analytical performance characteristics and clinical utility for the diagnosis and therapeutic monitoring of chronic HCV infections. The limit of detection (LOD), linearity, precision, specificity, matrix equivalence of plasma and serum, and quantitative agreement with the COBAS ® AmpliPrep/COBAS ® TaqMan ® HCV Test version 2.0 ("CAP/CTM HCV v2") were evaluated. Clinical utility for the diagnosis of chronic HCV infection was demonstrated by testing plasma from HCV seropositive individuals and comparing results to a nucleic acid amplification test (NAAT) approved for use in the diagnosis of chronic hepatitis C. Clinical specificity was investigated by testing plasma from HCV antibody negative subjects with non-HCV related liver diseases. Utility for monitoring treatment response was defined by testing plasma collected during treatment of HCV genotypes (GT) 1, 2, and 3 and determining positive predictive value (PPV), negative predictive value (NPV) and the odds ratio (OR) for predicting cure (sustained virologic response 12 weeks after treatment cessation, "SVR12"). The cobas HCV test demonstrated an LOD of at least 15 IU/mL and measurable range from 15 to at least 1.0E + 08 IU/mL (1.2-8.0 log 10 IU/mL) for GT 1-6, with high accuracy (≤0.16 log 10 difference) and precision (standard deviation 0.04-0.14 log 10 ) throughout the linear range. Paired plasma and serum samples showed highly correlated performance (R 2  = 0.97). Quantification was 100% specific for HCV in analytical studies. Correlation with CAP/CTM HCV v2 was high in patient samples (mean titer difference: 0.05 log 10 with a 95% CI: 0.03-0.06 log 10 ). For the diagnosis of chronic HCV, positive and negative percent agreement between cobas HCV and the comparator NAAT were 98.8-100% on the cobas 6800 and 8800 systems. Clinical specificity of cobas HCV using samples from HCV antibody negative subjects with non-HCV related liver diseases was 99.6% and 100% on cobas 6800 and 8800 systems. In therapeutic monitoring and SVR12 prediction during experimental treatment for chronic HCV GT 1 infections, undetectable HCV RNA by cobas HCV at different on-treatment weeks had a PPV 76.8%-79.4%, NPV 29.9%-100%, and OR 1.64-47.52. During therapy of HCV GT 2 and GT 3, treatment week 4 and 12 results were: PPV, 84.7% and 75.3%; NPV, 47.8% and 50.0%; OR, 5.09 and 3.05. The cobas HCV test is highly sensitive, specific, and accurate HCV RNA test for GT 1-6. It demonstrates excellent correlation with the FDA-approved CAP/CTM HCV v2 test. It is useful clinically for detection of active HCV infection in individuals that have had a positive anti-HCV antibody test result and in monitoring treatment response. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

African americans are less likely to have clearance of hepatitis C virus infection: the findings from recent U.S. population data.

PubMed

Mir, Heshaam M; Stepanova, Maria; Afendy, Mariam; Kugelmas, Marcelo; Younossi, Zobair M

2012-09-01

Hepatitis C virus (HCV) is the most common cause of chronic liver disease in the United States. African Americans are known to have a higher prevalence of HCV and lower response to anti-HCV therapy. The aim of this study is to assess the differences in the prevalence of chronic HCV infection in according to patients' ethnic background. We used the recent National Health and Nutrition Examination Survey with extensive clinical and laboratory data. Active HCV infection was defined as having HCV-positive antibody with detectable HCV RNA by polymerase chain reaction. HCV clearance was defined as HCV-positive antibody with negative HCV RNA. Clinico-demographic data were compared between anti-HCV positive individuals with or without HCV clearance. The stratum-specific χ test for independence was used. Logistic regression was used to identify independent predictors of HCV clearance. P-values ≤0.05 were considered statistically significant. All analyses were run using SAS 9.1 and SUDAAN 10.0. The cohort included 14,750 adults (age 47.6 ± 0.75 y, 64% white, 21% African American, 10% Hispanics, and 63% male). Of these, 1.32 ± 0.11% were anti-HCV positive with 75.94 ± 4.72% having active HCV viremia. The only parameter significantly different between those who did or did not clear HCV was the proportion of African Americans: 8.0 ± 3.7% versus 24.9 ± 5.0%, P=0.0163. Indeed, the rate of HCV clearance was lowest among African Americans (9.3 ± 3.5%) as compared with both whites (27.2 ± 6.5%) and Hispanics 31.2 ± 9.1% (P<0.05). In multivariate analysis, the only independent predictor of active HCV infection was African American race: odds ratio (95% confidence interval)=3.80 (1.31-11.06), P=0.0151. African Americans not only have lower response to anti-HCV therapy but also are less likely to naturally clear HCV, potentially contributing to higher prevalence of HCV.

“Hepatitis C treatment turned me around:” Psychological and Behavioral Transformation Related to Hepatitis C Treatment

PubMed Central

Peyser, D; Nahvi, S; Arnsten, JH; Litwin, AH

2016-01-01

Background Hepatitis C (HCV) is a significant public health problem that primarily affects current and former substance users. However, individuals with a history of substance use are less likely to have access to or engage in HCV care. Psychological and behavioral barriers prevent many HCV-infected individuals from initiating or engaging in HCV treatment. This study aimed to investigate the psychological and behavioral experiences of current and former substance users receiving HCV treatment within a combined methadone and primary care clinic in the United States. Methods We conducted 31 semi-structured qualitative interviews with opioid-dependent adults enrolled in an integrated HCV treatment program within a methadone maintenance clinic in the Bronx, NY. We used thematic analysis, informed by grounded theory, and inquired about perceptions of HCV before and after initiating HCV treatment, reasons for initiating HCV treatment, and the decision to participate in individual versus group HCV treatment. Results Participants described psychological and behavioral transformation over the course of HCV treatment. These included reductions in internalized stigma and shame related to HCV and addiction, increases in HCV disclosure and self-care, reductions in substance use, and new desire to help others who are living with HCV. Conclusions Integrating HCV treatment with methadone maintenance has the potential to create psychological and behavioral transformations among substance using adults, including reductions in HCV- and addiction-related shame and improvements in overall self-care. PMID:26096534

"Hepatitis C treatment turned me around:" Psychological and behavioral transformation related to hepatitis C treatment.

PubMed

Batchelder, A W; Peyser, D; Nahvi, S; Arnsten, J H; Litwin, A H

2015-08-01

Hepatitis C (HCV) is a significant public health problem that primarily affects current and former substance users. However, individuals with a history of substance use are less likely to have access to or engage in HCV care. Psychological and behavioral barriers prevent many HCV-infected individuals from initiating or engaging in HCV treatment. This study aimed to investigate the psychological and behavioral experiences of current and former substance users receiving HCV treatment within a combined methadone and primary care clinic in the United States. We conducted 31 semi-structured qualitative interviews with opioid-dependent adults enrolled in an integrated HCV treatment program within a methadone maintenance clinic in the Bronx, NY. We used thematic analysis, informed by grounded theory, and inquired about perceptions of HCV before and after initiating HCV treatment, reasons for initiating HCV treatment, and the decision to participate in individual versus group HCV treatment. Participants described psychological and behavioral transformation over the course of HCV treatment. These included reductions in internalized stigma and shame related to HCV and addiction, increases in HCV disclosure and self-care, reductions in substance use, and new desire to help others who are living with HCV. Integrating HCV treatment with methadone maintenance has the potential to create psychological and behavioral transformations among substance using adults, including reductions in HCV- and addiction-related shame and improvements in overall self-care. Copyright © 2015. Published by Elsevier Ireland Ltd.

Assembly of Slx4 signaling complexes behind DNA replication forks.

PubMed

Balint, Attila; Kim, TaeHyung; Gallo, David; Cussiol, Jose Renato; Bastos de Oliveira, Francisco M; Yimit, Askar; Ou, Jiongwen; Nakato, Ryuichiro; Gurevich, Alexey; Shirahige, Katsuhiko; Smolka, Marcus B; Zhang, Zhaolei; Brown, Grant W

2015-08-13

Obstructions to replication fork progression, referred to collectively as DNA replication stress, challenge genome stability. In Saccharomyces cerevisiae, cells lacking RTT107 or SLX4 show genome instability and sensitivity to DNA replication stress and are defective in the completion of DNA replication during recovery from replication stress. We demonstrate that Slx4 is recruited to chromatin behind stressed replication forks, in a region that is spatially distinct from that occupied by the replication machinery. Slx4 complex formation is nucleated by Mec1 phosphorylation of histone H2A, which is recognized by the constitutive Slx4 binding partner Rtt107. Slx4 is essential for recruiting the Mec1 activator Dpb11 behind stressed replication forks, and Slx4 complexes are important for full activity of Mec1. We propose that Slx4 complexes promote robust checkpoint signaling by Mec1 by stably recruiting Dpb11 within a discrete domain behind the replication fork, during DNA replication stress. © 2015 The Authors.

Prevalence of occult hepatitis C virus infection in the Iranian patients with human immunodeficiency virus infection.

PubMed

Bokharaei-Salim, Farah; Keyvani, Hossein; Esghaei, Maryam; Zare-Karizi, Shohreh; Dermenaki-Farahani, Sahar-Sadat; Hesami-Zadeh, Khashayar; Fakhim, Shahin

2016-11-01

Occult hepatitis C virus (HCV) infection is a new form of chronic HCV infection described by the presence of the genomic HCV-RNA in liver biopsy and/or peripheral blood mononuclear cell (PBMC) samples, and undetectable levels or absence of HCV-RNA and in the absence or presence of anti HCV antibodies in the plasma specimens. The aim of the present study was to evaluate the occurrence of occult HCV infection (OCI) among Iranian subjects infected with human immunodeficiency virus (HIV) using RT-nested PCR. From March 2014 until April 2015, 109 Iranian patients with established HIV infection were enrolled in this cross-sectional study. After extraction of viral RNA from the plasma and PBMC samples, HCV-RNA status was examined by RT-nested PCR using primers from the 5'-NTR. HCV genotyping was conducted using RFLP analysis. For the confirmation of HCV genotyping by RFLP method, the PCR products were sequenced. Of the 109 patients, 50 were positive for antibodies against HCV. The HCV-RNA was detected in PBMC specimens in 6 (10.2%) out of the total 59 patients negative for anti-HCV Abs and undetectable plasma HCV-RNA and also from 4 (8.0%) out of the total 50 patients positive for anti-HCV Abs and undetectable plasma HCV-RNA. HCV genotyping analysis showed that 6 (60.0%) patients were infected with HCV subtype 3a, 3 (30.0%) were infected with HCV subtype 1a and 1 (10.0%) patient was infected with HCV subtype 1b. This study revealed the incidence of OCI (9.2%) in HIV-infected Iranian patients. Hence, designing prospective studies focusing on the detection of OCI in these patients would provide more information. J. Med. Virol. 88:1960-1966, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Obstetrical and neonatal outcomes among women infected with hepatitis C and their infants.

PubMed

Money, Deborah; Boucoiran, Isabelle; Wagner, Emily; Dobson, Simon; Kennedy, Aaron; Lohn, Zoe; Krajden, Mel; Yoshida, Eric M

2014-09-01

(1) To describe obstetrical and neonatal outcomes among a cohort of hepatitis C virus (HCV) infected women, comparing HCV RNA positive to HCV RNA negative women; (2) to characterize virologic and hepatic parameters associated with HCV infection during pregnancy; and (3) to describe the rate of HCV vertical transmission. We prospectively enrolled 145 HCV-positive pregnant women across British Columbia between 2000 and 2003. Participating women were monitored during pregnancy and their infants were followed to assess them for HCV infection. Maternal HCV RNA was assessed close to delivery. Seventy percent of women reported injection drug use as their primary risk factor for HCV acquisition. Observed rates of intrauterine fetal death, preterm delivery, small for gestational age, and low birth weight infants were 3.4%, 17.9%, 11.3%, and 12.5%, respectively, without a significant association with maternal HCV RNA status. The rate of cholestasis was 5.6% in the HCV RNA-positive group (6/108) and 2.8% in the HCV RNA-negative group (1/37) (P = 0.496). Serum alanine aminotransferase levels decreased significantly through pregnancy, and were significantly higher in HCV RNA-positive women than in HCV RNA-negative women after controlling for cholestasis, co-infections, and alcohol consumption. Among the HCV RNA-positive women, the median FIB-4 score was 0.67 (IQR 0.56 to 0.76) in the first trimester, 0.74 (IQR 0.52 to 1.18) in the second trimester, and 0.89 (IQR 0.52 to 1.09) in the third trimester (P = 0.02). The median HCV viral load at delivery was 424 561 IU/mL. The vertical transmission rate was 4.7% in HCV RNA-positive women, with no cases in HCV RNA-negative women. Because of the high rates of poor obstetrical outcomes found in this prospective cohort, population-level screening for HCV in pregnancy should be considered.

Transcriptional machinery of TNF-α-inducible YTH domain containing 2 (YTHDC2) gene.

PubMed

Tanabe, Atsushi; Konno, Junpei; Tanikawa, Kenya; Sahara, Hiroeki

2014-02-01

We previously demonstrated that a cellular factor, cyclosporin A (CsA) associated helicase-like protein (CAHL) that is identical to YTH domain containing 2 (YTHDC2), forms trimer complex with cyclophilin B and NS5B of hepatitis C virus (HCV) and facilitates HCV genome replication. Gene expression of YTHDC2 was shown in tumor cell lines and tumor necrosis factor (TNF)-α-treated hepatocytes, but not in untreated. However, the function of YTHDC2 in the tumor cells and the mechanism by which the YTHDC2 gene is transcribed in these cells is largely unknown. We first evaluated that the role of YTHDC2 in the proliferation of hepatocellular carcinoma (HCC) cell line Huh7 using RNA interference and found that YTHDC2-downregulated Huh7 were significantly decreased cell growth as compared to control. We next demonstrated that the cAMP response element (CRE) site in the promoter region of the YTHDC2 gene is critical for YTHDC2 transcription. To further investigate the transcription factors bound to the CRE site, we performed chromatin immunoprecipitation assays. Our findings demonstrate that c-Jun and ATF-2 bind to the CRE site in Huh7, and that TNF-α induces the biological activity of these transcription factors in hepatocytes as well as Huh7. Moreover, treatment with the HDAC inhibitor, trichostatin A (TSA), reduces YTHDC2 expression in Huh7 and in TNF-α-stimulated hepatocytes. Collectively, these data show that YTHDC2 plays an important role in tumor cells growth and activation/recruitment of c-Jun and ATF-2 to the YTHDC2 promoter is necessary for the transcription of YTHDC2, and that HDAC activity is required for the efficient expression of YTHDC2 in both of hepatocyte and HCC cells. Copyright © 2013 Elsevier B.V. All rights reserved.

Performance of the New Bayer VERSANT HCV RNA 3.0 assay for quantitation of hepatitis C virus RNA in plasma and serum: conversion to international units and comparison with the Roche COBAS Amplicor HCV Monitor, Version 2.0, assay.

PubMed

Beld, Marcel; Sentjens, Roel; Rebers, Sjoerd; Weegink, Christine; Weel, Jan; Sol, Cees; Boom, René

2002-03-01

We have evaluated the VERSANT HCV RNA 3.0. Assay (HCV 3.0 bDNA assay) (Bayer Diagnostics, Berkeley, Calif.), which is an improved signal amplification procedure for the HCV 2.0 bDNA assay for the quantitation of hepatitis C virus (HCV) RNA in serum or plasma of HCV-infected individuals. The HCV 3.0 bDNA assay has a linear dynamic range of 2.5 x 10(3) to 4.0 x 10(7) HCV RNA copies per ml (c/ml). The performance of the HCV 3.0 bDNA assay was evaluated using three different test panels. An overall specificity of 96.8% relative to the detection limit of the HCV 3.0 bDNA assay was found. The intra- and interrun reproducibilities for both the dilution panel and the NAP (AcroMetrix, Benicia, Calif.) panel were consistent with coefficients of variation of less than 9%. Quantitation with the HCV 3.0 bDNA assay was linear over the entire range of both panels (ranges of 4.4 x 10(3) to 3.5 x 10(6) c/ml and 5 x 10(3) to 2 x 10(6) IU/ml, respectively), with correlation coefficients of 0.999, slopes close to one, and intercepts close to zero. The regression equation indicated that 1 IU corresponded to about 4.8 copies of HCV RNA. A correlation coefficient of 0.941 was found for HCV RNA values (in international units per milliliter) obtained from the HCV 3.0 bDNA assay and the HCV Monitor version 2.0 assay (HCV Monitor 2.0 assay) (Roche Diagnostic Systems, Branchburg, N.J.). Quantitative results obtained close to the lower limit of the HCV 3.0 bDNA assay might imply that its lower limit should be reconsidered and raised, if necessary. It appeared that quantitation values obtained from the HCV Monitor 2.0 assay of between 5 x 10(2) and 10(5) IU/ml were in general higher than those obtained from the HCV 3.0 bDNA assay, whereas values obtained from the HCV Monitor 2.0 assay were underestimated for samples with HCV RNA levels above 10(5) IU/ml.

Performance of the New Bayer VERSANT HCV RNA 3.0 Assay for Quantitation of Hepatitis C Virus RNA in Plasma and Serum: Conversion to International Units and Comparison with the Roche COBAS Amplicor HCV Monitor, Version 2.0, Assay

PubMed Central

Beld, Marcel; Sentjens, Roel; Rebers, Sjoerd; Weegink, Christine; Weel, Jan; Sol, Cees; Boom, René

2002-01-01

We have evaluated the VERSANT HCV RNA 3.0. Assay (HCV 3.0 bDNA assay) (Bayer Diagnostics, Berkeley, Calif.), which is an improved signal amplification procedure for the HCV 2.0 bDNA assay for the quantitation of hepatitis C virus (HCV) RNA in serum or plasma of HCV-infected individuals. The HCV 3.0 bDNA assay has a linear dynamic range of 2.5 × 103 to 4.0 × 107 HCV RNA copies per ml (c/ml). The performance of the HCV 3.0 bDNA assay was evaluated using three different test panels. An overall specificity of 96.8% relative to the detection limit of the HCV 3.0 bDNA assay was found. The intra- and interrun reproducibilities for both the dilution panel and the NAP (AcroMetrix, Benicia, Calif.) panel were consistent with coefficients of variation of less than 9%. Quantitation with the HCV 3.0 bDNA assay was linear over the entire range of both panels (ranges of 4.4 × 103 to 3.5 × 106 c/ml and 5 × 103 to 2 × 106 IU/ml, respectively), with correlation coefficients of 0.999, slopes close to one, and intercepts close to zero. The regression equation indicated that 1 IU corresponded to about 4.8 copies of HCV RNA. A correlation coefficient of 0.941 was found for HCV RNA values (in international units per milliliter) obtained from the HCV 3.0 bDNA assay and the HCV Monitor version 2.0 assay (HCV Monitor 2.0 assay) (Roche Diagnostic Systems, Branchburg, N.J.). Quantitative results obtained close to the lower limit of the HCV 3.0 bDNA assay might imply that its lower limit should be reconsidered and raised, if necessary. It appeared that quantitation values obtained from the HCV Monitor 2.0 assay of between 5 × 102 and 105 IU/ml were in general higher than those obtained from the HCV 3.0 bDNA assay, whereas values obtained from the HCV Monitor 2.0 assay were underestimated for samples with HCV RNA levels above 105 IU/ml. PMID:11880394

Utilization of Signal-to-Cutoff Ratio of Hepatitis C Virus Antibody Assay in Predicting HCV Viremia among Hemodialysis Patients.

PubMed

Kao, Hao-Hsi; Chen, Kuo-Su; Lin, Chih-Lang; Chang, Jia-Jang; Lee, Chien-Hung

2015-01-01

Hepatitis C virus (HCV) infection is a common cause of acute and chronic hepatitis among the hemodialysis population. To prevent cross infection between hemodialysis patients during the hemodialysis procedure, routine screening of anti-HCV antibody is recommended. However, a reactive anti-HCV EIA test is not equal to active HCV infection. An expensive RT-PCR study is required to confirm HCV viremia. This will significantly increase the cost burden because payment for each hemodialysis treatment is very low in Taiwan. Thus, it is useful to identify parameters that could predict HCV viremia among anti-HCV-reactive patients. In this study, we examined the usefulness of signal-to-cut (S/CO) ratio of anti-HCV antibody in discriminating HCV viremia from non-viremia among the anti-HCV-reactive hemodialysis population. In a cross-sectional measurement of anti-HCV antibody among 369 chronic hemodialysis patients, 44 showed reactive and 9 grey zone reaction for anti-HCV. These 53 patients underwent further blood tests for the measurement of AST, ALT and HCV RNA (by RT-PCR). The results of RT-PCR were used as a dependent variable. Then, S/CO ratios of anti-HCV, serum AST, ALT levels, age and duration of hemodialysis were used as independent variables to undergo ROC curve and logistic regression analysis. Thirty-six of the 53 reactive and grey zone patients were positive for HCV RNA in the RT-PCR study. Patients who were positive for HCV RNA had a higher S/CO ratio (p < 0.01), higher AST and ALT levels (p < 0.01), and longer duration on hemodialysis (p < 0.05) than those negative for HCV RNA. Logistic regression revealed that only S/CO ratio was a significant predictor for HCV viremia (p = 0.004). ROC curve analysis showed that S/CO ratio had a highest area under curve (0.967, p < 0.001), followed by ALT (0.826, p < 0.001), AST (0.778, p = 0.001), duration on hemodialysis (0.606, p = 0.215) and age (0.426, p = 0.386) in discriminating HCV viremia from non-viremia. Using a cutoff S/CO ratio of 65, we can confirm HCV viremia with a diagnostic specificity of 100%, sensitivity of 80.1% and positive predictive value of 100%. S/CO ratio is a useful indicator in predicting HCV viremia among anti-HCV-reactive hemodialysis patients. Patients with an S/CO ratio >65 can be regarded as those with active HCV infection. Alternatively, patients with reactive anti-HCV but with an S/CO ratio <65 should receive further RT-PCR test. © 2015 S. Karger AG, Basel.

Cost-effectiveness of rapid HCV testing and simultaneous rapid HCV and HIV testing in substance abuse treatment programs

PubMed Central

Schackman, Bruce R.; Leff, Jared A.; Barter, Devra M.; DiLorenzo, Madeline A.; Feaster, Daniel J.; Metsch, Lisa R.; Freedberg, Kenneth A.; Linas, Benjamin P.

2014-01-01

Aims To evaluate the cost-effectiveness of rapid hepatitis C virus (HCV) and simultaneous HCV/HIV antibody testing in substance abuse treatment programs. Design We used a decision analytic model to compare the cost-effectiveness of no HCV testing referral or offer, off-site HCV testing referral, on-site rapid HCV testing offer, and on-site rapid HCV and HIV testing offer. Base case inputs included 11% undetected chronic HCV, 0.4% undetected HIV, 35% HCV co-infection among HIV-infected, 53% linked to HCV care after testing antibody positive, and 67% linked to HIV care. Disease outcomes were estimated from established computer simulation models of HCV (HEP-CE) and HIV (CEPAC). Setting and Participants Data on test acceptance and costs were from a national randomized trial of HIV testing strategies conducted at 12 substance abuse treatment programs in the USA. Measurements Lifetime costs (2011 US dollars) and quality-adjusted life years (QALYs) discounted at 3% annually; incremental cost-effectiveness ratios (ICERs) Findings On-site rapid HCV testing had an ICER of $18,300/QALY compared with no testing, and was more efficient than (dominated) off-site HCV testing referral. On-site rapid HCV and HIV testing had an ICER of $64,500/QALY compared with on-site rapid HCV testing alone. In one and two-way sensitivity analyses, the ICER of on-site rapid HCV and HIV testing remained <$100,000/QALY, except when undetected HIV prevalence was <0.1% or when we assumed frequent HIV testing elsewhere. The ICER remained <$100,000/QALY in approximately 90% of probabilistic sensitivity analyses. Conclusions On-site rapid hepatitis C virus and HIV testing in substance abuse treatment programs is cost-effective at a <$100,000/ quality-adjusted life years threshold. PMID:25291977

Increased risk of severe recurrence of hepatitis C virus in liver transplant recipients of donation after cardiac death allografts.

PubMed

Hernandez-Alejandro, Roberto; Croome, Kris P; Quan, Douglas; Mawardi, Mohamed; Chandok, Natasha; Dale, Cheryl; McAlister, Vivian; Levstik, Mark A; Wall, William; Marotta, Paul

2011-09-27

In hepatitis C virus (HCV) recipients of donation after cardiac death (DCD) grafts, there is suggestion of lower rates of graft survival, indicating that DCD grafts themselves may represent a significant risk factor for severe recurrence of HCV. We evaluated all DCD liver transplant recipients from August 2006 to February 2011 at our center. Recipients with HCV who received a DCD graft (group 1, HCV+ DCD, n=17) were compared with non-HCV recipients transplanted with a DCD graft (group 2, HCV- DCD, n=15), and with a matched group of HCV recipients transplanted with a donation after brain death (DBD) graft (group 3, HCV+ DBD, n=42). A trend of poorer graft survival was seen in HCV+ patients who underwent a DCD transplant (group 1) compared with HCV- patients who underwent a DCD transplant (group 2) (P=0.14). Importantly, a statistically significant difference in graft survival was seen in HCV+ patients undergoing DCD transplant (group 1) (73%) as compared with DBD transplant (group 3) (93%)(P=0.01). There was a statistically significant increase in HCV recurrence at 3 months (76% vs. 16%) (P=0.005) and severe HCV recurrence within the first year (47% vs. 10%) in the DCD group (P=0.004). HCV recurrence is more severe and progresses more rapidly in HCV+ recipients who receive grafts from DCD compared with those who receive grafts from DBD. DCD liver transplantation in HCV+ recipients is associated with a higher rate of graft failure compared with those who receive grafts from DBD. Caution must be taken when using DCD grafts in HCV+ recipients.

Hepatitis C virus testing in adults living with HIV: a need for improved screening efforts.

PubMed

Yehia, Baligh R; Herati, Ramin S; Fleishman, John A; Gallant, Joel E; Agwu, Allison L; Berry, Stephen A; Korthuis, P Todd; Moore, Richard D; Metlay, Joshua P; Gebo, Kelly A

2014-01-01

Guidelines recommend hepatitis C virus (HCV) screening for all people living with HIV (PLWH). Understanding HCV testing practices may improve compliance with guidelines and can help identify areas for future intervention. We evaluated HCV screening and unnecessary repeat HCV testing in 8,590 PLWH initiating care at 12 U.S. HIV clinics between 2006 and 2010, with follow-up through 2011. Multivariable logistic regression examined the association between patient factors and the outcomes: HCV screening (≥1 HCV antibody tests during the study period) and unnecessary repeat HCV testing (≥1 HCV antibody tests in patients with a prior positive test result). Overall, 82% of patients were screened for HCV, 18% of those screened were HCV antibody-positive, and 40% of HCV antibody-positive patients had unnecessary repeat HCV testing. The likelihood of being screened for HCV increased as the number of outpatient visits rose (adjusted odds ratio 1.02, 95% confidence interval 1.01-1.03). Compared to men who have sex with men (MSM), patients with injection drug use (IDU) were less likely to be screened for HCV (0.63, 0.52-0.78); while individuals with Medicaid were more likely to be screened than those with private insurance (1.30, 1.04-1.62). Patients with heterosexual (1.78, 1.20-2.65) and IDU (1.58, 1.06-2.34) risk compared to MSM, and those with higher numbers of outpatient (1.03, 1.01-1.04) and inpatient (1.09, 1.01-1.19) visits were at greatest risk of unnecessary HCV testing. Additional efforts to improve compliance with HCV testing guidelines are needed. Leveraging health information technology may increase HCV screening and reduce unnecessary testing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, Zhonghua; Qiao, Ling; Zhou, Yan

Research highlights: {yields} A chimeric subgenomic HCV replicon expresses HCV-3a NS5A in an HCV-1b backbone. {yields} HCV-3a NS5A increases mature SREBP-1c protein level. {yields} HCV-3a NS5A activates SREBP-1c transcription. {yields} Domain II of HCV-3a NS5A is more effective in SREBP-1c promoter activation. {yields} Transcription factor Sp1 is required for SREBP-1c activation by HCV-3a NS5A. -- Abstract: Steatosis is an important clinical manifestation of hepatitis C virus (HCV) infection. The molecular mechanisms of HCV-associated steatosis are not well understood. Sterol regulatory element-binding protein-1c (SREBP-1c) is a key transcription factor which activates the transcription of lipogenic genes. Here we showed that themore » nuclear, mature SREBP-1c level increases in the nucleus of replicon cells expressing HCV-3a nonstructural protein-5A (NS5A). We further showed that HCV-3a NS5A up-regulates SREBP-1c transcription. Additional analysis showed that transcriptional factor Sp1 is involved in SREBP-1c activation by HCV-3a NS5A because inhibition of Sp1 activity by mithramycin A or a dominant-negative Sp1 construct abrogated SREBP-1c promoter activation by HCV-3a NS5A. In addition, chromatin immunoprecipitation (ChIP) assay demonstrated enhanced binding of Sp1 on the SREBP-1c promoter in HCV-3a NS5A replicon cells. These results showed that HCV-3a NS5A activates SREBP-1c transcription through Sp1. Taken together, our results suggest that HCV-3a NS5A is a contributing factor for steatosis caused by HCV-3a infection.« less

Seroprevalence of HCV among Cairo University students in Egypt.

PubMed

Esmat, Gamal; Raziky, Maissa El; Nabeel, Mohammed M; Maher, Rabab; Zakaria, Zeinab

2016-08-01

Hepatitis C virus (HCV) is highly prevalent in Egypt. This work aimed at determining the seroprevalence of HCV among Cairo University students. The present study included 3,000 students from Cairo University, Egypt. Blood sample was obtained from each participant to be tested for HCV seromarker. HCV RNA detection by polymerase chain reaction (PCR) was carried out for those with positive anti-HCV. Overall prevalence rate of HCV antibody (anti-HCV) was 4.6%. It showed that the prevalence was relatively higher among females (86/1660; 5.2%) while males (51/1340; 3.8%) with no significant difference. PCR for HCV RNA was detected in 31.4% of the HCV antibody positive subjects (43/137). Which showed statistical significant difference between males (29/51) and females (14/86) at P = 0.001. Despite the prevalence rate reported in the present study was similar to anti-HCV prevalence among persons in the same age group, confirmed that HCV infection is detected among Cairo University students. J. Med. Virol. 88:1384-1387, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Racial Disparities in Hepatitis C Treatment Eligibility.

PubMed

Sims, Omar; Pollio, David; Hong, Barry; North, Carol

2017-01-01

Hepatitis C (HCV) is more prevalent in African Americans than in any other racial group in the United States. However, African Americans are more likely to be deemed ineligible for HCV treatment than non-African Americans. There has been limited research into the origins of racial disparities in HCV treatment eligibility. The purpose of this study was to compare medical and non-medical characteristics commonly assessed in clinical practice that could potentially contribute to HCV treatment ineligibility disparities between African American and non-African American patients. Patients with confirmed HCV RNA considering treatment (n = 309) were recruited from university-affiliated and VA liver and infectious disease clinics. African Americans and non-African Americans did not differ in prevalence of lifetime and current psychiatric disorders and risky behaviors, and HCV knowledge. HCV clinical characteristics were similar between both groups in terms of HCV exposure history, number of months aware of HCV diagnosis, stage of fibrosis, and HCV virologic levels. African Americans did have higher proportions of diabetes, renal disease, and bleeding ulcer. No clinical evidence was found to indicate that African Americans should be more often deemed ineligible for HCV treatment than other racial groups. Diabetes and renal disease do not fully explain the HCV treatment ineligibility racial disparity, because HCV patients with these conditions are priority patients for HCV treatment because of their greater risk for cirrhosis, steatosis, and hepatocellular carcinoma. The findings suggest that an underlying contributor to the HCV treatment eligibility disparity disfavoring African Americans could be racial discrimination.

An international perspective on using opioid substitution treatment to improve hepatitis C prevention and care for people who inject drugs: Structural barriers and public health potential.

PubMed

Perlman, David C; Jordan, Ashly E; Uuskula, Anneli; Huong, Duong Thi; Masson, Carmen L; Schackman, Bruce R; Des Jarlais, Don C

2015-11-01

People who inject drugs (PWID) are central to the hepatitis C virus (HCV) epidemic. Opioid substitution treatment (OST) of opioid dependence has the potential to play a significant role in the public health response to HCV by serving as an HCV prevention intervention, by treating non-injection opioid dependent people who might otherwise transition to non-sterile drug injection, and by serving as a platform to engage HCV infected PWID in the HCV care continuum and link them to HCV treatment. This paper examines programmatic, structural and policy considerations for using OST as a platform to improve the HCV prevention and care continuum in 3 countries-the United States, Estonia and Viet Nam. In each country a range of interconnected factors affects the use OST as a component of HCV control. These factors include (1) that OST is not yet provided on the scale needed to adequately address illicit opioid dependence, (2) inconsistent use of OST as a platform for HCV services, (3) high costs of HCV treatment and health insurance policies that affect access to both OST and HCV treatment, and (4) the stigmatization of drug use. We see the following as important for controlling HCV transmission among PWID: (1) maintaining current HIV prevention efforts, (2) expanding efforts to reduce the stigmatization of drug use, (3) expanding use of OST as part of a coordinated public health approach to opioid dependence, HIV prevention, and HCV control efforts, (4) reductions in HCV treatment costs and expanded health system coverage to allow population level HCV treatment as prevention and OST as needed. The global expansion of OST and use of OST as a platform for HCV services should be feasible next steps in the public health response to the HCV epidemic, and is likely to be critical to efforts to eliminate or eradicate HCV. Copyright © 2015 Elsevier B.V. All rights reserved.

Prevalence of IL-28B and ITPA genotypes in Chinese Han population infected persistently with hepatitis C virus genotype 6 or HCV-1.

PubMed

Zhang, Xiao-Hong; Cai, Qing-Xian; Hong, Chun-Xia; Lin, Chao-Shuang; Zhao, Zhi-Xin

2013-07-01

The geographic distribution, demographics, epidemiology, host factors, and clinical characteristics of persistent HCV-6 infection in China need further characterization. This multicenter study enrolled 63 patients with persistent HCV-6 infection and 63 patients with persistent HCV-1 infection as controls. Blood biochemistry, quantitation of HCV RNA levels, and identification of host IL-28B genotypes (rs12979860, rs8099917, and rs12980275) and ITPA genotype (rs1127354) were performed to estimate potential variability in host factors that may affect response to treatment. The mean HCV-6 RNA level (3.8E6 IU/ml) was significantly higher than that in patients infected with HCV-1 (1.7E6 IU/ml; P < 0.001). Patients persistently infected with HCV-6 had a high prevalence of IL-28B rs12979860 CC genotype (92.1%), rs8099917 TT genotype (93.7%), and rs12980275 AA genotype (90.5%). Their prevalence in patients infected with HCV-1 was only modestly lower (82.5%, 84.1%, and 82.5%, respectively; P > 0.05). The inosine triphosphate pyrophosphatase (ITPA) SNP rs1127354 CC genotype was present in 66.7% of patients infected with HCV-6, comparable to that of patients infected with HCV-1 (65.1%; P > 0.05). There were no differences in the liver function, proportion of hepatic cirrhosis patients or patients with increased serum glucose between these two groups. Persistent HCV-6 infection in Chinese Han is found mainly in the southern China. Chinese Han with chronic HCV-1 or HCV-6 infection have IL-28B genotypes, suggesting responsiveness to interferon-based pharmacotherapy. Most patients (67%) possess the ITPA genotype associated with susceptibility to ribavirin-induced hemolysis. The routes of transmission for HCV-6 genotype were more diversified than HCV-1 genotype. The outbreak of HCV-6 infection through blood transfusion progressed faster than HCV-1. Copyright © 2013 Wiley Periodicals, Inc.

NS3 genomic sequencing and phylogenetic analysis as alternative to a commercially available assay to reliably determine hepatitis C virus subtypes 1a and 1b

PubMed Central

Neukam, Karin; Martínez, Alfredo P.; Culasso, Andrés C. A.; Ridruejo, Ezequiel; García, Gabriel

2017-01-01

Objective To evaluate the use of hepatitis C virus (HCV) NS3 sequencing as alternative to the comercially available Versant HCV 2.0 reverse hybridization line-probe assay (LiPA 2.0) to determine HCV genotype 1 (HCV-1) subtypes. Patients and methods A cohort of 104 patients infected by HCV-1 according to LiPA 2.0 was analyzed in a cross-sectional study conducted in patients seen from January 2012 to June 2016 at an outpatient clinic in Buenos Aires, Argentina. Results The samples were included within well supported subtype clades: 64 with HCV-1b and 39 with HCV-1a infection. Twenty of the HCV-1a infected patientes were included in a supported sub-clade “1” and 19 individuals were among the basal sub-clade “2”. LiPA 2.0 failed to subtype HCV-1 in 20 (19.2%) individuals. Subtype classification determined by NS3 direct sequencing showed that 2/18 (11.1%) of the HCV-1a-infected patients as determined by LiPA 2.0 were in fact infected by HCV-1b. Of the HCV-1b-infected according to LiPA 2.0, 10/66 (15.2%) patients showed HCV-1a infection according to NS3 sequencing. Overall misclassification was 14.3% (κ-index for the concordance with NS3 sequencing = 0.635). One (1%) patient was erroneously genotyped as HCV-1 and was revealed as HCV genotype 4 infection. Conclusions Genomic sequencing of the HCV NS3 region represents an adequate alternative since it provides reliable genetic information. It even distinguishes between HCV-1a clades related to resistance-associated substitutions to HCV protease inhibitors, it provides reliable genetic information for genotyping/subgenotyping and simultaneously allows to determine the presence of resistance-associated substitutions to currently recommended DAAs. PMID:28753662

Partial sequencing analysis of the NS5B region confirmed the predominance of hepatitis C virus genotype 1 infection in Jeddah, Saudi Arabia.

PubMed

El Hadad, Sahar; Al-Hamdan, Hesa; Linjawi, Sabah

2017-01-01

Chronic hepatitis C virus (HCV) infection and its progression are major health problems that many countries including Saudi Arabia are facing. Determination of HCV genotypes and subgenotypes is critical for epidemiological and clinical analysis and aids in the determination of the ideal treatment strategy that needs to be followed and the expected therapy response. Although HCV infection has been identified as the second most predominant type of hepatitis in Saudi Arabia, little is known about the molecular epidemiology and genetic variability of HCV circulating in the Jeddah province of Saudi Arabia. The aim of this study was to determine the dominance of various HCV genotypes and subgenotypes circulating in Jeddah using partial sequencing of the NS5B region. To the best of our knowledge, this is the first study of its kind in Saudi Arabia. To characterize HCV genotypes and subgenotypes, serum samples from 56 patients with chronic HCV infection were collected and subjected to partial NS5B gene amplification and sequence analysis. Phylogenetic analysis of the NS5B partial sequences revealed that HCV/1 was the predominant genotype (73%), followed by HCV/4 (24.49%) and HCV/3 (2.04%). Moreover, pairwise analysis also confirmed these results based on the average specific nucleotide distance identity: ±0.112, ±0.112, and ±0.179 for HCV/1, HCV/4, and HCV/3, respectively, without any interference between genotypes. Notably, the phylogenetic tree of the HCV/1 subgenotypes revealed that all the isolates (100%) from the present study belonged to the HCV/1a subgenotype. Our findings also revealed similarities in the nucleotide sequences between HCV circulating in Saudi Arabia and those circulating in countries such as Morocco, Egypt, Canada, India, Pakistan, and France. These results indicated that determination of HCV genotypes and subgenotypes based on partial sequence analysis of the NS5B region is accurate and reliable for HCV subtype determination.

HCV Prevalence in Asian Americans in California.

PubMed

Lin, Oliver N; Chang, Christine; Lee, Joyce; Do, Ailinh; Martin, Marina; Martin, Andy; Nguyen, Mindie H

2017-02-01

The World Health Organization estimates that 170 million persons are infected with HCV worldwide, but only 22 million are from the Americas and Europe, compared to 94 million from Asia. HCV prevalence in the general US population is 1.6 %, but data for Asian Americans are limited. Our goal was to examine HCV prevalence in Asian Americans in a large ethnically diverse patient cohort seeking primary care at a free clinic in Northern California. A total of 1347 consecutive patients were seen from September 2009 to October 2012 and were studied via individual chart review using case report forms. HCV infection was defined as positive HCV antibody (anti-HCV) or HCV RNA by PCR. 699 out of 1347 patients were screened for HCV. Asian Americans comprised 57.2 % of these patients and 29 (4.1 %) patients tested positive for HCV. Of these 29 HCV-positive patients, 22 (75.9 %) were Asian, yielding a prevalence of 5.5 % for Asians and 2.3 % for non-Asians (P = 0.038). The highest HCV prevalence was seen in Vietnamese patients at 7.9 %, and 6.0 % in Chinese patients. Of the HCV-positive Asians, none had a history of intravenous drug use (IVDU), tattoos, or sexual exposure. On multivariate analysis, significant independent predictors for positive HCV infection were male gender (OR 2.53, P = 0.02) and presence of known risk factors (OR 21.1, P < 0.001). However, older age and Asian ethnicity were found to be significant predictors of HCV infection (OR 1.03, P = 0.05 and 2.31, P = 0.066, respectively). In our study, HCV prevalence in patients seeking routine primary care was 5.5 % in Asian Americans, which was over double the prevalence for non-Asians at 2.3 %. Known risk factors were also notably absent in Asian patients with HCV infection. The high prevalence of HCV in Asian-Americans is likely reflective of the higher prevalence of HCV in their countries of origin in Asia. Asian-Americans immigrants from endemic countries are at higher risk of HCV infection and should be screened for HCV, regardless of their exposure risk profile.

Mechanisms and regulation of DNA replication initiation in eukaryotes

PubMed Central

Parker, Matthew W.; Botchan, Michael R.; Berger, James M.

2017-01-01

Cellular DNA replication is initiated through the action of multiprotein complexes that recognize replication start sites in the chromosome (termed origins) and facilitate duplex DNA melting within these regions. In a given cell cycle, initiation occurs only once per origin and each round of replication is tightly coupled to cell division. To avoid aberrant origin firing and re-replication, eukaryotes tightly regulate two events in the initiation process: loading of the replicative helicase, MCM2-7, onto chromatin by the Origin Recognition Complex (ORC), and subsequent activation of the helicase by incorporation into a complex known as the CMG. Recent work has begun to reveal the details of an orchestrated and sequential exchange of initiation factors on DNA that give rise to a replication-competent complex, the replisome. Here we review the molecular mechanisms that underpin eukaryotic DNA replication initiation – from selecting replication start sites to replicative helicase loading and activation – and describe how these events are often distinctly regulated across different eukaryotic model organisms. PMID:28094588

Mechanisms and regulation of DNA replication initiation in eukaryotes.

PubMed

Parker, Matthew W; Botchan, Michael R; Berger, James M

2017-04-01

Cellular DNA replication is initiated through the action of multiprotein complexes that recognize replication start sites in the chromosome (termed origins) and facilitate duplex DNA melting within these regions. In a typical cell cycle, initiation occurs only once per origin and each round of replication is tightly coupled to cell division. To avoid aberrant origin firing and re-replication, eukaryotes tightly regulate two events in the initiation process: loading of the replicative helicase, MCM2-7, onto chromatin by the origin recognition complex (ORC), and subsequent activation of the helicase by its incorporation into a complex known as the CMG. Recent work has begun to reveal the details of an orchestrated and sequential exchange of initiation factors on DNA that give rise to a replication-competent complex, the replisome. Here, we review the molecular mechanisms that underpin eukaryotic DNA replication initiation - from selecting replication start sites to replicative helicase loading and activation - and describe how these events are often distinctly regulated across different eukaryotic model organisms.

Hepatitis C management by addiction medicine physicians: Results from a national survey

PubMed Central

Litwin, Alain H.; Kunins, Hillary V.; Berg, Karina M.; Federman, Alex D.; Heavner, Karyn K.; Gourevitch, Marc N.; Arnsten, Julia H.

2010-01-01

Drug users are disproportionately affected by hepatitis C virus (HCV), yet they face barriers to health care that place them at risk for levels of HCV-related care that are lower than those of nondrug users. Substance abuse treatment physicians may treat more HCV-infected persons than other generalist physicians, yet little is known about how such physicians facilitate HCV-related care. We conducted a nationwide survey of American Society of Addiction Medicine physicians (n = 320) to determine substance abuse physicians’ HCV-related management practices and to describe factors associated with these practices. We found that substance abuse treatment physicians promote several elements of HCV-related care, including screening for HCV antibodies, recommending vaccinations against hepatitis A and B, and referring patients to subspecialists for HCV treatment. Substance abuse physicians who also provide primary medical or HIV-related care were most likely to facilitate HCV-related care. A significant minority of physicians were either providing HCV antiviral treatment or willing to provide HCV antiviral treatment. PMID:17379472

Hepatitis C Virus: Patients' Risk Factors and Knowledge in an Urban Clinic Providing Wound Care.

PubMed

Pieper, Barbara; Sickon, Katharine

2018-03-01

Affecting about 3.2 million people in the United States, hepatitis C virus (HCV) is the primary cause of chronic liver disease and a global health challenge. Hepatitis C virus can affect the functioning of the liver, the health of the person, and thus wound healing. This quality project explores risk factors of HCV; self-reported screening, occurrence, and treatment; and knowledge of HCV in patients seeking wound care in an urban clinic. Demographic risk factors, HCV history, and responses to a 22-item true-false-don't know HCV Knowledge Test were obtained from 58 patients. Risk factors included age (mean, 61.07 years), male sex (n = 41), non-Hispanic black race/ethnicity (n = 51), and history of injection drugs (n = 38). Thirty-nine (67.2%) stated they had been screened for HCV; 31 were told they were infected. Only 14 went to a clinic for HCV care and 11 reported they were treated. The mean number of correct answers on the HCV Knowledge Test was 14.4 (standard deviation, 5.7). This urban clinic had patients with multiple HCV risk factors; they often lacked HCV screening and/or referral for treatment. Their HCV knowledge was generally low. As a major public health problem that could impact wound healing, wound care practitioners should ask patients about their HCV status, encourage HCV screening and care, and provide HCV information.

Zika Virus Persistently Infects and Is Basolaterally Released from Primary Human Brain Microvascular Endothelial Cells.

PubMed

Mladinich, Megan C; Schwedes, John; Mackow, Erich R

2017-07-11

Zika virus (ZIKV) is a mosquito-borne Flavivirus that has emerged as the cause of encephalitis and fetal microencephaly in the Americas. ZIKV uniquely persists in human bodily fluids for up to 6 months, is sexually transmitted, and traverses the placenta and the blood-brain barrier (BBB) to damage neurons. Cells that support persistent ZIKV replication and mechanisms by which ZIKV establishes persistence remain enigmatic but central to ZIKV entry into protected neuronal compartments. The endothelial cell (EC) lining of capillaries normally constrains transplacental transmission and forms the BBB, which selectively restricts access of blood constituents to neurons. We found that ZIKV (strain PRVABC59) persistently infects and continuously replicates in primary human brain microvascular ECs (hBMECs), without cytopathology, for >9 days and following hBMEC passage. ZIKV did not permeabilize hBMECs but was released basolaterally from polarized hBMECs, suggesting a direct mechanism for ZIKV to cross the BBB. ZIKV-infected hBMECs were rapidly resistant to alpha interferon (IFN-α) and transiently induced, but failed to secrete, IFN-β and IFN-λ. Global transcriptome analysis determined that ZIKV constitutively induced IFN regulatory factor 7 (IRF7), IRF9, and IFN-stimulated genes (ISGs) 1 to 9 days postinfection, despite persistently replicating in hBMECs. ZIKV constitutively induced ISG15, HERC5, and USP18, which are linked to hepatitis C virus (HCV) persistence and IFN regulation, chemokine CCL5, which is associated with immunopathogenesis, as well as cell survival factors. Our results reveal that hBMECs act as a reservoir of persistent ZIKV replication, suggest routes for ZIKV to cross hBMECs into neuronal compartments, and define novel mechanisms of ZIKV persistence that can be targeted to restrict ZIKV spread. IMPORTANCE ZIKV persists in patients, crossing placental and neuronal barriers, damaging neurons, and causing fetal microencephaly. We found that ZIKV persistently infects brain endothelial cells that normally protect neurons from viral exposure. hBMECs are not damaged by ZIKV infection and, analogous to persistent HCV infection, ZIKV constitutively induces and evades antiviral ISG and IFN responses to continuously replicate in hBMECs. As a result, hBMECs provide a protective niche for systemic ZIKV spread and a viral reservoir localized in the normally protective blood-brain barrier. Consistent with the spread of ZIKV into neuronal compartments, ZIKV was released basolaterally from hBMECs. Our findings define hBMEC responses that contribute to persistent ZIKV infection and potential targets for clearing ZIKV infections from hBMECs. These results further suggest roles for additional ZIKV-infected ECs to facilitate viral spread and persistence in the protected placental, retinal, and testicular compartments. Copyright © 2017 Mladinich et al.

PriC-mediated DNA replication restart requires PriC complex formation with the single-stranded DNA-binding protein.

PubMed

Wessel, Sarah R; Marceau, Aimee H; Massoni, Shawn C; Zhou, Ruobo; Ha, Taekjip; Sandler, Steven J; Keck, James L

2013-06-14

Frequent collisions between cellular DNA replication complexes (replisomes) and obstacles such as damaged DNA or frozen protein complexes make DNA replication fork progression surprisingly sporadic. These collisions can lead to the ejection of replisomes prior to completion of replication, which, if left unrepaired, results in bacterial cell death. As such, bacteria have evolved DNA replication restart mechanisms that function to reload replisomes onto abandoned DNA replication forks. Here, we define a direct interaction between PriC, a key Escherichia coli DNA replication restart protein, and the single-stranded DNA-binding protein (SSB), a protein that is ubiquitously associated with DNA replication forks. PriC/SSB complex formation requires evolutionarily conserved residues from both proteins, including a pair of Arg residues from PriC and the C terminus of SSB. In vitro, disruption of the PriC/SSB interface by sequence changes in either protein blocks the first step of DNA replication restart, reloading of the replicative DnaB helicase onto an abandoned replication fork. Consistent with the critical role of PriC/SSB complex formation in DNA replication restart, PriC variants that cannot bind SSB are non-functional in vivo. Single-molecule experiments demonstrate that PriC binding to SSB alters SSB/DNA complexes, exposing single-stranded DNA and creating a platform for other proteins to bind. These data lead to a model in which PriC interaction with SSB remodels SSB/DNA structures at abandoned DNA replication forks to create a DNA structure that is competent for DnaB loading.

Earlier Detection of Hepatitis C Virus Infection Through Routine Hepatitis C Virus Antibody Screening of Human Immunodeficiency Virus-Positive Men Who Have Sex With Men Attending A Sexually Transmitted Infection Outpatient Clinic: A Longitudinal Study.

PubMed

van Rooijen, Martijn; Heijman, Titia; de Vrieze, Nynke; Urbanus, Anouk; Speksnijder, Arjen; van Leeuwen, Petra; de Vries, Henry; Prins, Maria

2016-09-01

In 2007, routine hepatitis C virus (HCV) antibody testing was introduced for men who have sex with men (MSM) with a human immunodeficiency virus (HIV)-positive or unknown status attending a Dutch sexually transmitted infection (STI) outpatient clinic. We evaluated whether this screening resulted in additional and earlier HCV diagnoses among MSM who also attend HIV clinics. At first STI consultation, HIV-positive MSM and MSM opting-out of HIV testing (HIV-status-unknown) were tested for HCV antibodies (anti-HCV). During follow-up consultations, only previously HCV-negative men were tested. Retrospectively, STI clinic and HIV clinic HCV diagnosis dates were compared. One hundred twelve (6.4%) of 1742 (95% confidence interval [CI], 5.3-7.6%) HIV-positive and 3 (0.7%) of 446 (95% CI, 0.2-2.0%) HIV-status-unknown MSM tested anti-HCV-positive at first consultation. During follow-up consultations, 32 HIV-positive (incidence HCV-positive: 2.35/100 person years (PY) (95% CI, 1.66-3.33)) and 0 (1-sided, 97.5% CI, 0.0-3.76) HIV-status-unknown MSM became anti-HCV-positive. Four (11.8%) of 34 HIV-positive MSM notified by their sexual partner of HCV tested anti-HCV-positive.Of 163 HIV-positive MSM with HCV antibodies, 78 reported a history of HCV. HCV diagnosis data at the HIV clinic was requested for the remaining 85 MSM and available for 54 MSM. Of these 54 MSM, 28 (51.9%) had their first HCV diagnosis at the STI clinic, of whom 7 concurrently with HIV. At their next scheduled HIV clinic consultation, 3 HCV cases probably would have been missed. The introduction of routine anti-HCV testing at the STI outpatient clinic resulted in additional and earlier HCV detection among HIV-positive MSM. Testing should be continued among HIV-positive MSM, at least for those not (yet) under the care of an HIV clinic and those notified of HCV by their sexual partner.

Performance comparison of new generation HCV core antigen test versus HCV RNA test in management of hepatitis C virus infection.

PubMed

Çetiner, Salih; Çetin Duran, Alev; Kibar, Filiz; Yaman, Akgün

2017-06-01

The study has evaluated the performance of HCV core antigen (Cag) test by comparing HCV RNA PCR assay which is considered the gold standard for management of HCV infection. Totally, 132 samples sent for HCV RNA (real-time PCR) test were included in the study. Anti-HCV antibody test and HCV Cag test were performed by chemiluminescent enzyme immunoassay (CMEI). Anti-HCV test was positive in all samples. HCV RNA was detected in 112/132 (84.8%) samples, and HCV Cag in 105/132 (79.5%). The most common HCV genotype was genotype 1 (86%). Considering the HCV RNA test as gold standard; the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Cag test were found to be 93.75%, 100%, 100%, 74.07% and 94.69%, respectively, and paired test results were detected as highly concordant. A high level of correlation was seen between HCV RNA and Cag tests, however, the concordance between the two tests appeared to be disrupted at viral loads lower than 10 3 IU/mL. On the contrary, the correlation reached significance for the values higher than 10 3 IU/mL. Viral loads were in the 17-2500IU/mL range for the negative results for Cag test. Pearson's correlation coefficient revealed a considerably high correlation. The concordance between HCV RNA and Cag tests was disrupted under a viral load lower than 10 3 IU/mL. Therefore, it would be appropriate to consider cost effectiveness, advantages and limitations of the HCV RNA and Cag tests during the decision on which method to use for patient management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrating multiple programme and policy approaches to hepatitis C prevention and care for injection drug users: a comprehensive approach.

PubMed

Birkhead, Guthrie S; Klein, Susan J; Candelas, Alma R; O'Connell, Daniel A; Rothman, Jeffrey R; Feldman, Ira S; Tsui, Dennis S; Cotroneo, Richard A; Flanigan, Colleen A

2007-10-01

New York State is home to an estimated 230,000 individuals chronically infected with hepatitis C virus (HCV) and roughly 171,500 active injection drug users (IDUs). HCV/HIV co-infection is common and models of service delivery that effectively meet IDUs' needs are required. A HCV strategic plan has stressed integration. HCV prevention and care are integrated within health and human service settings, including HIV/AIDS organisations and drug treatment programmes. Other measures that support comprehensive HCV services for IDUs include reimbursement, clinical guidelines, training and HCV prevention education. Community and provider collaborations inform programme and policy development. IDUs access 5 million syringes annually through harm reduction/syringe exchange programmes (SEPs) and a statewide syringe access programme. Declines in HCV prevalence amongst IDUs in New York City coincided with improved syringe availability. New models of care successfully link IDUs at SEPs and in drug treatment to health care. Over 7000 Medicaid recipients with HCV/HIV co-infection had health care encounters related to their HCV in a 12-month period and 10,547 claims for HCV-related medications were paid. The success rate of transitional case management referrals to drug treatment is over 90%. Training and clinical guidelines promote provider knowledge about HCV and contribute to quality HCV care for IDUs. Chart reviews of 2570 patients with HIV in 2004 documented HCV status 97.4% of the time, overall, in various settings. New HCV surveillance systems are operational. Despite this progress, significant challenges remain. A comprehensive, public health approach, using multiple strategies across systems and mobilizing multiple sectors, can enhance IDUs access to HCV prevention and care. A holisitic approach with integrated services, including for HCV-HIV co-infected IDUs is needed. Leadership, collaboration and resources are essential.