IFNβ/TNFα synergism induces a non-canonical STAT2/IRF9-dependent pathway triggering a novel DUOX2 NADPH Oxidase-mediated airway antiviral response

PubMed Central

Fink, Karin; Martin, Lydie; Mukawera, Esperance; Chartier, Stéfany; De Deken, Xavier; Brochiero, Emmanuelle; Miot, Françoise; Grandvaux, Nathalie

2013-01-01

Airway epithelial cells are key initial innate immune responders in the fight against respiratory viruses, primarily via the secretion of antiviral and proinflammatory cytokines that act in an autocrine/paracrine fashion to trigger the establishment of an antiviral state. It is currently thought that the early antiviral state in airway epithelial cells primarily relies on IFNβ secretion and the subsequent activation of the interferon-stimulated gene factor 3 (ISGF3) transcription factor complex, composed of STAT1, STAT2 and IRF9, which regulates the expression of a panoply of interferon-stimulated genes encoding proteins with antiviral activities. However, the specific pathways engaged by the synergistic action of different cytokines during viral infections, and the resulting physiological outcomes are still ill-defined. Here, we unveil a novel delayed antiviral response in the airways, which is initiated by the synergistic autocrine/paracrine action of IFNβ and TNFα, and signals through a non-canonical STAT2- and IRF9-dependent, but STAT1-independent cascade. This pathway ultimately leads to the late induction of the DUOX2 NADPH oxidase expression. Importantly, our study uncovers that the development of the antiviral state relies on DUOX2-dependent H2O2 production. Key antiviral pathways are often targeted by evasion strategies evolved by various pathogenic viruses. In this regard, the importance of the novel DUOX2-dependent antiviral pathway is further underlined by the observation that the human respiratory syncytial virus is able to subvert DUOX2 induction. PMID:23545780

[Antiviral activity of phosprenyl and gamapren against infection caused by influenza a (H5N1) virus in cell culture].

PubMed

Sanin, A V; Deryabin, P G; Narovlyansky, A N; Pronin, A V; Kozhevnikova, T N

2017-01-01

The antiviral activity of Phosprenyl and Gamapren in vitro against highly pathogenic strain of avian influenza H5N1 virus was studied. Inoculation of the virus to the susceptible cell culture led to development of the cytopathogenic effect. Preliminary introduction of Phosprenyl and Gamapren an hour prior to infecting the cells with virus 10.0 TCID50 dose completely inhibited the cytopathogenic activity of the virus. At higher doses of virus (100.0 TCID50) significant inhibition of the infectious activity of the virus was observed: 70% of infected cells survived under the action of Phosprenyl, and 90% under the action of Gamapren. With the introduction of the preparations simultaneously with the infection of cells with virus at a dose of 10.0 TCID50 virtually 100% of infected cells survived, while in control cultures death of 100% of the cells occurred. After infection with the virus at a dose of 100.0 TCID50 Phosprenyl and Gamapren caused 50% protection of the cells. The antiviral effect of the drugs Phosprenyl and Gamapren may be associated not only with their virulicidal, but with anti-viral activity as well.

Antiviral activity in vitro of two preparations of the herbal medicinal product Sinupret® against viruses causing respiratory infections.

PubMed

Glatthaar-Saalmüller, B; Rauchhaus, U; Rode, S; Haunschild, J; Saalmüller, A

2011-12-15

Sinupret(®), a herbal medicinal product made from Gentian root, Primula flower, Elder flower, Sorrel herb, and Verbena herb is frequently used in the treatment of acute and chronic rhinosinusitis and respiratory viral infections such as common cold. To date little is known about its potential antiviral activity. Therefore experiments have been performed to measure the antiviral activity of Sinupret(®) oral drops (hereinafter referred to as "oral drops") and Sinupret(®) dry extract (hereinafter referred to as "dry extract"), in vitro against a broad panel of both enveloped and non-enveloped human pathogenic RNA and DNA viruses known to cause infections of the upper respiratory tract: influenza A, Chile 1/83 (H1N1) virus (FluA), Porcine Influenza A/California/07/2009 (H1N1) virus (pFluA), parainfluenza type 3 virus (Para 3), respiratory syncytial virus, strain Long (RSV), human rhinovirus B subtype 14 (HRV 14), coxsackievirus subtype A9 (CA9), and adenovirus C subtype 5 (Adeno 5). Concentration-dependent antiviral activity (EC(50) between 13.8 and 124.8 μg/ml) of Sinupret(®) was observed against RNA as well as DNA viruses independent of a viral envelope. Remarkable antiviral activity was shown against Adeno 5, HRV 14 and RSV in which dry extract was significantly superior to oral drops. This could be ascertained with different assays as plaque-reduction assays in plaque forming units (PFU), the analyses of a cytopathogenic effect (CPE) and with enzyme immunoassays (ELISA) to determine the amount of newly synthesised virus. Our results demonstrate that Sinupret(®) shows a broad spectrum of antiviral activity in vitro against viruses commonly known to cause respiratory infections. Copyright © 2011 Elsevier GmbH. All rights reserved.

SPL7013 Gel (VivaGel®) Retains Potent HIV-1 and HSV-2 Inhibitory Activity following Vaginal Administration in Humans

PubMed Central

Price, Clare F.; Tyssen, David; Sonza, Secondo; Davie, Ashley; Evans, Sonya; Lewis, Gareth R.; Xia, Shirley; Spelman, Tim; Hodsman, Peter; Moench, Thomas R.; Humberstone, Andrew; Paull, Jeremy R.A.; Tachedjian, Gilda

2011-01-01

SPL7013 Gel (VivaGel®) is a microbicide in development for prevention of HIV and HSV. This clinical study assessed retention and duration of antiviral activity following vaginal administration of 3% SPL7013 Gel in healthy women. Participants received 5 single doses of product with ≥5 days between doses. A cervicovaginal fluid (CVF) sample was collected using a SoftCup™ pre-dose, and immediately, or 1, 3, 12 or 24 h post-dose. HIV-1 and HSV-2 antiviral activities of CVF samples were determined in cell culture assays. Antiviral activity in the presence of seminal plasma was also tested. Mass and concentration of SPL7013 in CVF samples was determined. Safety was assessed by reporting of adverse events. Statistical analysis was performed using the Wilcoxon signed-rank test with Bonferroni adjustment; p≤0.003 was significant. Eleven participants completed the study. Inhibition of HIV-1 and HSV-2 by pre-dose CVF samples was negligible. CVF samples obtained immediately after dosing almost completely inhibited (median, interquartile range) HIV-1 [96% (95,97)] and HSV-2 [86% (85,94)], and activity was maintained in all women at 3 h (HIV-1 [96% (95,98), p = 0.9]; HSV-2 [94% (91,97), p = 0.005]). At 24 h, >90% of initial HIV-1 and HSV-2 inhibition was maintained in 6/11 women. SPL7013 was recovered in CVF samples obtained at baseline (46% of 105 mg dose). At 3 and 24 h, 22 mg and 4 mg SPL7013, respectively, were recovered. More than 70% inhibition of HIV-1 and HSV-2 was observed if there was >0.5 mg SPL7013 in CVF samples. High levels of antiviral activity were retained in the presence of seminal plasma. VivaGel was well tolerated with no signs or symptoms of vaginal, vulvar or cervical irritation reported. Potent antiviral activity was observed against HIV-1 and HSV-2 immediately following vaginal administration of VivaGel, with activity maintained for at least 3 h post-dose. The data provide evidence of antiviral activity in a clinical setting, and suggest VivaGel could be administered up to 3 h before coitus. Trial Registration The study is registered at ClinicalTrials.gov under identifier: NCT00740584 PMID:21935377

Antiviral activity of sandalwood oil against herpes simplex viruses-1 and -2.

PubMed

Benencia, F; Courrèges, M C

1999-05-01

Sandalwood oil, the essential oil of Santalum album L., was tested for in vitro antiviral activity against Herpes simplex viruses-1 and -2. It was found that the replication of these viruses was inhibited in the presence of the oil. This effect was dose-dependent and more pronounced against HSV-1. A slight diminution of the effect was observed at higher multiplicity of infections. The oil was not virucidal and showed no cytotoxicity at the concentrations tested.

Potentiated virucidal activity of pomegranate rind extract (PRE) and punicalagin against Herpes simplex virus (HSV) when co-administered with zinc (II) ions, and antiviral activity of PRE against HSV and aciclovir-resistant HSV

PubMed Central

Houston, David M. J.; Bugert, Joachim J.; Denyer, Stephen P.

2017-01-01

Background There is a clinical need for new therapeutic products against Herpes simplex virus (HSV). The pomegranate, fruit of the tree Punica granatum L, has since ancient times been linked to activity against infection. This work probed the activity of pomegranate rind extract (PRE) and co-administered zinc (II) ions. Materials and methods PRE was used in conjunction with zinc (II) salts to challenge HSV-1 and aciclovir-resistant HSV in terms of virucidal plaque assay reduction and antiviral activities in epithelial Vero host cells. Cytotoxicity was determined by the MTS assay using a commercial kit. Results Zinc sulphate, zinc citrate, zinc stearate and zinc gluconate demonstrated similar potentiated virucidal activity with PRE against HSV-1 by up to 4-fold. A generally parabolic relationship was observed when HSV-1 was challenged with PRE and varying concentrations of ZnSO4, with a maximum potentiation factor of 5.5. Punicalagin had 8-fold greater virucidal activity than an equivalent mass of PRE. However, antiviral data showed that punicalagin had significantly lower antiviral activity compared to the activity of PRE (EC50 = 0.56 μg mL-1) a value comparable to aciclovir (EC50 = 0.18 μg mL-1); however, PRE also demonstrated potency against aciclovir-resistant HSV (EC50 = 0.02 μg mL-1), whereas aciclovir showed no activity. Antiviral action of PRE was not influenced by ZnSO4. No cytotoxicity was detected with any test solution. Conclusions The potentiated virucidal activity of PRE by coadministered zinc (II) has potential as a multi-action novel topical therapeutic agent against HSV infections, such as coldsores. PMID:28665969

Neuraminidase inhibition of Dietary chlorogenic acids and derivatives - potential antivirals from dietary sources.

PubMed

Gamaleldin Elsadig Karar, Mohamed; Matei, Marius-Febi; Jaiswal, Rakesh; Illenberger, Susanne; Kuhnert, Nikolai

2016-04-01

Plants rich in chlorogenic acids (CGAs), caffeic acids and their derivatives have been found to exert antiviral effects against influenza virus neuroaminidase. In this study several dietary naturally occurring chlorogenic acids, phenolic acids and derivatives were screened for their inhibitory activity against neuroaminidases (NAs) from C. perfringens, H5N1 and recombinant H5N1 (N-His)-Tag using a fluorometric assay. There was no significant difference in inhibition between the different NA enzymes. The enzyme inhibition results indicated that chlorogenic acids and selected derivatives, exhibited high activities against NAs. It seems that the catechol group from caffeic acid was important for the activity. Dietary CGA therefore show promise as potential antiviral agents. However, caffeoyl quinic acids show low bioavailibility and are intensly metabolized by the gut micro flora, only low nM concentrations are observed in plasma and urine, therefore a systemic antiviral effect of these compounds is unlikely. Nevertheless, gut floral metabolites with a catechol moiety or structurally related dietary phenolics with a catechol moiety might serve as interesting compounds for future investigations.

Identification of light-independent inhibition of human immunodeficiency virus-1 infection through bioguided fractionation of Hypericum perforatum

PubMed Central

Maury, Wendy; Price, Jason P; Brindley, Melinda A; Oh, ChoonSeok; Neighbors, Jeffrey D; Wiemer, David F; Wills, Nickolas; Carpenter, Susan; Hauck, Cathy; Murphy, Patricia; Widrlechner, Mark P; Delate, Kathleen; Kumar, Ganesh; Kraus, George A; Rizshsky, Ludmila; Nikolau, Basil

2009-01-01

Background Light-dependent activities against enveloped viruses in St. John's Wort (Hypericum perforatum) extracts have been extensively studied. In contrast, light-independent antiviral activity from this species has not been investigated. Results Here, we identify the light-independent inhibition of human immunodeficiency virus-1 (HIV-1) by highly purified fractions of chloroform extracts of H. perforatum. Both cytotoxicity and antiviral activity were evident in initial chloroform extracts, but bioassay-guided fractionation produced fractions that inhibited HIV-1 with little to no cytotoxicity. Separation of these two biological activities has not been reported for constituents responsible for the light-dependent antiviral activities. Antiviral activity was associated with more polar subfractions. GC/MS analysis of the two most active subfractions identified 3-hydroxy lauric acid as predominant in one fraction and 3-hydroxy myristic acid as predominant in the other. Synthetic 3-hydroxy lauric acid inhibited HIV infectivity without cytotoxicity, suggesting that this modified fatty acid is likely responsible for observed antiviral activity present in that fraction. As production of 3-hydroxy fatty acids by plants remains controversial, H. perforatum seedlings were grown sterilely and evaluated for presence of 3-hydroxy fatty acids by GC/MS. Small quantities of some 3-hydroxy fatty acids were detected in sterile plants, whereas different 3-hydroxy fatty acids were detected in our chloroform extracts or field-grown material. Conclusion Through bioguided fractionation, we have identified that 3-hydroxy lauric acid found in field grown Hypericum perforatum has anti-HIV activity. This novel anti-HIV activity can be potentially developed into inexpensive therapies, expanding the current arsenal of anti-retroviral agents. PMID:19594941

TRIM25 Is Required for the Antiviral Activity of Zinc Finger Antiviral Protein

PubMed Central

Zheng, Xiaojiao; Wang, Xinlu; Tu, Fan; Wang, Qin; Fan, Zusen

2017-01-01

ABSTRACT Zinc finger antiviral protein (ZAP) is a host factor that specifically inhibits the replication of certain viruses by binding to viral mRNAs and repressing the translation and/or promoting the degradation of target mRNA. In addition, ZAP regulates the expression of certain cellular genes. Here, we report that tripartite motif-containing protein 25 (TRIM25), a ubiquitin E3 ligase, is required for the antiviral activity of ZAP. Downregulation of endogenous TRIM25 abolished ZAP's antiviral activity. The E3 ligase activity of TRIM25 is required for this regulation. TRIM25 mediated ZAP ubiquitination, but the ubiquitination of ZAP itself did not seem to be required for its antiviral activity. Downregulation of endogenous ubiquitin or overexpression of the deubiquitinase OTUB1 impaired ZAP's activity. We provide evidence indicating that TRIM25 modulates the target RNA binding activity of ZAP. These results uncover a mechanism by which the antiviral activity of ZAP is regulated. IMPORTANCE ZAP is a host antiviral factor that specifically inhibits the replication of certain viruses, including HIV-1, Sindbis virus, and Ebola virus. ZAP binds directly to target mRNA, and it represses the translation and promotes the degradation of target mRNA. While the mechanisms by which ZAP posttranscriptionally inhibits target RNA expression have been extensively studied, how its antiviral activity is regulated is not very clear. Here, we report that TRIM25, a ubiquitin E3 ligase, is required for the antiviral activity of ZAP. Downregulation of endogenous TRIM25 remarkably abolished ZAP's activity. TRIM25 is required for ZAP optimal binding to target mRNA. These results help us to better understand how the antiviral activity of ZAP is regulated. PMID:28202764

TRIM25 Is Required for the Antiviral Activity of Zinc Finger Antiviral Protein.

PubMed

Zheng, Xiaojiao; Wang, Xinlu; Tu, Fan; Wang, Qin; Fan, Zusen; Gao, Guangxia

2017-05-01

Zinc finger antiviral protein (ZAP) is a host factor that specifically inhibits the replication of certain viruses by binding to viral mRNAs and repressing the translation and/or promoting the degradation of target mRNA. In addition, ZAP regulates the expression of certain cellular genes. Here, we report that tripartite motif-containing protein 25 (TRIM25), a ubiquitin E3 ligase, is required for the antiviral activity of ZAP. Downregulation of endogenous TRIM25 abolished ZAP's antiviral activity. The E3 ligase activity of TRIM25 is required for this regulation. TRIM25 mediated ZAP ubiquitination, but the ubiquitination of ZAP itself did not seem to be required for its antiviral activity. Downregulation of endogenous ubiquitin or overexpression of the deubiquitinase OTUB1 impaired ZAP's activity. We provide evidence indicating that TRIM25 modulates the target RNA binding activity of ZAP. These results uncover a mechanism by which the antiviral activity of ZAP is regulated. IMPORTANCE ZAP is a host antiviral factor that specifically inhibits the replication of certain viruses, including HIV-1, Sindbis virus, and Ebola virus. ZAP binds directly to target mRNA, and it represses the translation and promotes the degradation of target mRNA. While the mechanisms by which ZAP posttranscriptionally inhibits target RNA expression have been extensively studied, how its antiviral activity is regulated is not very clear. Here, we report that TRIM25, a ubiquitin E3 ligase, is required for the antiviral activity of ZAP. Downregulation of endogenous TRIM25 remarkably abolished ZAP's activity. TRIM25 is required for ZAP optimal binding to target mRNA. These results help us to better understand how the antiviral activity of ZAP is regulated. Copyright © 2017 American Society for Microbiology.

Antiviral and Antioxidant Activities of Sulfated Galactomannans from Plants of Caatinga Biome.

PubMed

Marques, Márcia Maria Mendes; de Morais, Selene Maia; da Silva, Ana Raquel Araújo; Barroso, Naiara Dutra; Pontes Filho, Tadeu Rocha; Araújo, Fernanda Montenegro de Carvalho; Vieira, Ícaro Gusmão Pinto; Lima, Danielle Malta; Guedes, Maria Izabel Florindo

2015-01-01

Dengue represents a serious social and economic public health problem; then trying to contribute to improve its control, the objective of this research was to develop phytoterapics for dengue treatment using natural resources from Caatinga biome. Galactomannans isolated from Adenanthera pavonina L., Caesalpinia ferrea Mart., and Dimorphandra gardneriana Tull were chemically sulfated in order to evaluate the antioxidant, and antiviral activities and the role in the inhibition of virus DENV-2 in Vero cells. A positive correlation between the degree of sulfation, antioxidant and antiviral activities was observed. The sulfated galactomannans showed binding to the virus surface, indicating that they interact with DENV-2. The sulfated galactomannans from C. ferrea showed 96% inhibition of replication of DENV-2 followed by D. gardneriana (94%) and A. pavonina (77%) at 25 µg/mL and all sulfated galactomannans also showed antioxidant activity. This work is the first report of the antioxidant and antiviral effects of sulfated galactomannans against DENV-2. The results are very promising and suggest that these sulfated galactomannans from plants of Caatinga biome act in the early step of viral infection. Thus, sulfated galactomannans may act as an entry inhibitor of DENV-2.

Antiviral and Antioxidant Activities of Sulfated Galactomannans from Plants of Caatinga Biome

PubMed Central

Marques, Márcia Maria Mendes; de Morais, Selene Maia; da Silva, Ana Raquel Araújo; Barroso, Naiara Dutra; Pontes Filho, Tadeu Rocha; Araújo, Fernanda Montenegro de Carvalho; Vieira, Ícaro Gusmão Pinto; Lima, Danielle Malta; Guedes, Maria Izabel Florindo

2015-01-01

Dengue represents a serious social and economic public health problem; then trying to contribute to improve its control, the objective of this research was to develop phytoterapics for dengue treatment using natural resources from Caatinga biome. Galactomannans isolated from Adenanthera pavonina L., Caesalpinia ferrea Mart., and Dimorphandra gardneriana Tull were chemically sulfated in order to evaluate the antioxidant, and antiviral activities and the role in the inhibition of virus DENV-2 in Vero cells. A positive correlation between the degree of sulfation, antioxidant and antiviral activities was observed. The sulfated galactomannans showed binding to the virus surface, indicating that they interact with DENV-2. The sulfated galactomannans from C. ferrea showed 96% inhibition of replication of DENV-2 followed by D. gardneriana (94%) and A. pavonina (77%) at 25 µg/mL and all sulfated galactomannans also showed antioxidant activity. This work is the first report of the antioxidant and antiviral effects of sulfated galactomannans against DENV-2. The results are very promising and suggest that these sulfated galactomannans from plants of Caatinga biome act in the early step of viral infection. Thus, sulfated galactomannans may act as an entry inhibitor of DENV-2. PMID:26257815

Cycluridine: A novel antiviral effective against flaviviruses

PubMed Central

Galabov, Angel S; Mukova, Lucia; Abashev, Yuriy P; Wassilewa, Lilia; Tzvetkov, Petko; Minkov, Vassil; Barinskiy, Igor F; Rice, Charles M; Ouzounov, Sergey; Sidzhakova, Dorotea

2017-01-01

This review describes the contemporary state of research for antivirals effective against flaviviruses, especially focusing on inhibitors of the pestivirus causative agent of bovine viral diarrhoea virus. We highlight cycluridine, an originally synthesized Mannich’s base [a tetrahydro-2(1H)-pyrimidinones derivative], as a highly effective antiviral possessing a strong inhibitory effect on bovine viral diarrhoea virus replication. Cycluridine was active against replication of a wide variety of bovine viral diarrhoea virus strains in cell cultures. The drug-sensitive period in the bovine viral diarrhoea virus replication cycle included the latent period and the exponential phase; a 90-min delay in the peak of viral RNA synthesis was observed. Cycluridine administered orally manifested a pronounced protective effect in calves with natural mucosal disease/viral diarrhoea and calves experimentally infected with bovine viral diarrhoea virus. Its magnitude of activity and selectivity places cycluridine in the lead among all known substances with anti- bovine viral diarrhoea virus activity. Additionally, cycluridine applied subcutaneously showed anti-tick-born encephalitis virus activity, manifesting a marked protective effect in mice infected with tick-born encephalitis virus. Cycluridine could be a prospective antiviral in veterinary and medical practice for the treatment of bovine viral diarrhoea virus and other flavivirus infections. PMID:28768435

Cobalt Complexes as Antiviral and Antibacterial Agents

DTIC Science & Technology

2010-01-01

observed. Complex 26 has antibacterial activity against E. coli, S. aureus and Micrococcus lysodeikiticus, showing better growth inhibitory activity in...complexes exhibited activity towards E. coli, B. subtilis, S. aureus and Micrococcus lysodeikiticus. Figure 15. Selenium containing and

Inhibitory effect of the green tea molecule EGCG against dengue virus infection.

PubMed

Raekiansyah, Muhareva; Buerano, Corazon C; Luz, Mark Anthony D; Morita, Kouichi

2018-06-01

Dengue virus (DENV) infection is a major public health problem worldwide; however, specific antiviral drugs against it are not available. Hence, identifying effective antiviral agents for the prevention of DENV infection is important. In this study, we showed that the reportedly highly biologically active green-tea component epigallocatechin gallate (EGCG) inhibited dengue virus infection regardless of infecting serotype, but no or minimal inhibition was observed with other flaviviruses, including Japanese encephalitis virus, yellow fever virus, and Zika virus. EGCG exerted its antiviral effect mainly at the early stage of infection, probably by interacting directly with virions to prevent virus infection. Our results suggest that EGCG specifically targets DENV and might be used as a lead structure to develop an antiviral drug for use against the virus.

The lipid moiety of brincidofovir is required for in vitro antiviral activity against Ebola virus.

PubMed

McMullan, Laura K; Flint, Mike; Dyall, Julie; Albariño, César; Olinger, Gene G; Foster, Scott; Sethna, Phiroze; Hensley, Lisa E; Nichol, Stuart T; Lanier, E Randall; Spiropoulou, Christina F

2016-01-01

Brincidofovir (BCV) is the 3-hexadecyloxy-1-propanol (HDP) lipid conjugate of the acyclic nucleoside phosphonate cidofovir (CDV). BCV has established broad-spectrum activity against double-stranded DNA (dsDNA) viruses; however, its activity against RNA viruses has been less thoroughly evaluated. Here, we report that BCV inhibited infection of Ebola virus in multiple human cell lines. Unlike the mechanism of action for BCV against cytomegalovirus and other dsDNA viruses, phosphorylation of CDV to the diphosphate form appeared unnecessary. Instead, antiviral activity required the lipid moiety and in vitro activity against EBOV was observed for several HDP-nucleotide conjugates. Copyright © 2015. Published by Elsevier B.V.

Antiviral Regulation in Porcine Monocytic Cells at Different Activation States

PubMed Central

Rowland, Raymond R. R.

2014-01-01

ABSTRACT Monocytic cells, including macrophages and dendritic cells, exist in different activation states that are critical to the regulation of antimicrobial immunity. Many pandemic viruses are monocytotropic, including porcine reproductive and respiratory syndrome virus (PRRSV), which directly infects subsets of monocytic cells and interferes with antiviral responses. To study antiviral responses in PRRSV-infected monocytic cells, we characterized inflammatory cytokine responses and genome-wide profiled signature genes to investigate response pathways in uninfected and PRRSV-infected monocytic cells at different activation states. Our findings showed suppressed interferon (IFN) production in macrophages in non-antiviral states and an arrest of lipid metabolic pathways in macrophages at antiviral states. Importantly, porcine monocytic cells at different activation states were susceptible to PRRSV and responded differently to viral infection. Based on Gene Ontology (GO) analysis, two approaches were used to potentiate antiviral activity: (i) pharmaceutical modulation of cellular lipid metabolism and (ii) in situ PRRSV replication-competent expression of interferon alpha (IFN-α). Both approaches significantly suppressed exogenous viral infection in monocytic cells. In particular, the engineered IFN-expressing PRRSV strain eliminated exogenous virus infection and sustained cell viability at 4 days postinfection in macrophages. These findings suggest an intricate interaction of viral infection with the activation status of porcine monocytic cells. An understanding and integration of antiviral infection with activation status of monocytic cells may provide a means of potentiating antiviral immunity. IMPORTANCE Activation statuses of monocytic cells, including monocytes, macrophages (Mϕs), and dendritic cells (DCs), are critically important for antiviral immunity. Unfortunately, the activation status of porcine monocytic cells or how cell activation status functionally interacts with antiviral immunity remains largely unknown. This is a significant omission because many economically important porcine viruses are monocytotropic, including our focus, PRRSV, which alone causes nearly $800 million economic loss annually in the U.S. swine industries. PRRSV is ideal for deciphering how monocytic cell activation statuses interact with antiviral immunity, because it directly infects subsets of monocytic cells and subverts overall immune responses. In this study, we systematically investigate the activation status of porcine monocytic cells to determine the intricate interaction of viral infection with activation statuses and functionally regulate antiviral immunity within the framework of the activation paradigm. Our findings may provide a means of potentiating antiviral immunity and leading to novel vaccines for PRRS prevention. PMID:25056886

Reduction of cell viability induced by IFN-alpha generates impaired data on antiviral assay using Hep-2C cells.

PubMed

de Oliveira, Edson R A; Lima, Bruna M M P; de Moura, Wlamir C; Nogueira, Ana Cristina M de A

2013-12-31

Type I interferons (IFNs) exert an array of important biological functions on the innate immune response and has become a useful tool in the treatment of various diseases. An increasing demand in the usage of recombinant IFNs, mainly due to the treatment of chronic hepatitis C infection, augmented the need of quality control for this biopharmaceutical. A traditional bioassay for IFN potency assessment is the cytopathic effect reduction antiviral assay where a given cell line is preserved by IFN from a lytic virus activity using the cell viability as a frequent measure of end point. However, type I IFNs induce other biological effects such as cell-cycle arrest and apoptosis that can influence directly on viability of many cell lines. Here, we standardized a cytopathic effect reduction antiviral assay using Hep-2C cell/mengovirus combination and studied a possible impact of cell viability variations caused by IFN-alpha 2b on responses generated on the antiviral assay. Using the four-parameter logistic model, we observed less correlation and less linearity on antiviral assay when responses from IFN-alpha 2b 1000 IU/ml were considered in the analysis. Cell viability tests with MTT revealed a clear cell growth inhibition of Hep-2C cells under stimulation with IFN-alpha 2b. Flow cytometric cell-cycle analysis and apoptosis assessment showed an increase of S+G2 phase and higher levels of apoptotic cells after treatment with IFN-alpha 2b 1000 IU/ml under our standardized antiviral assay procedure. Considering our studied dose range, we also observed strong STAT1 activation on Hep-2C cells after stimulation with the higher doses of IFN-alpha 2b. Our findings showed that the reduction of cell viability driven by IFN-alpha can cause a negative impact on antiviral assays. We assume that the cell death induction and the cell growth inhibition effect of IFNs should also be considered while employing antiviral assay protocols in a quality control routine and emphasizes the importance of new approaches for IFN potency determination. Copyright © 2013 Elsevier B.V. All rights reserved.

Phytochemical screening and antiviral activity of some medicinal plants from the island Soqotra.

PubMed

Mothana, Ramzi A A; Mentel, Renate; Reiss, Christiane; Lindequist, Ulrike

2006-04-01

Methanol and hot-aqueous extracts of 25 different plant species, used in Yemeni traditional medicine and growing, partly as endemic plants, on the island Soqotra have been investigated for their antiviral activity. In addition, the phytochemical identification of the main chemical constituents was performed. The extracts were assayed in two in vitro viral systems, which used influenza virus type A/MDCK cells and herpes simplex virus type 1/Vero cells, at non-cytotoxic concentrations. The herpes simplex virus type 1 showed more sensitivity than the influenza virus type A against the extracts investigated. The methanol extracts of Boswellia ameero, Boswellia elongata, Buxus hildebrandtii, Cissus hamaderohensis, Cleome socotrana, Dracaena cinnabari, Exacum affine, Jatropha unicostata and Kalanchoe farinacea showed anti-influenza virus type A activity with 50% inhibition (IC50) concentrations ranging from 0.7 to 12.5 microg/mL. In addition, 17 plants of the 25 investigated exhibited anti-HSV-1 activity. The antiviral activity of some active extracts was also observed on a molecular level. Copyright 2006 John Wiley & Sons, Ltd.

Randomized, Placebo-Controlled, Single-Ascending-Dose Study of BMS-791325, a Hepatitis C Virus (HCV) NS5B Polymerase Inhibitor, in HCV Genotype 1 Infection

PubMed Central

Lemm, Julie; Eley, Timothy; Liu, Menping; Berglind, Anna; Sherman, Diane; Lawitz, Eric; Vutikullird, Apinya B.; Tebas, Pablo; Gao, Min; Pasquinelli, Claudio; Grasela, Dennis M.

2014-01-01

BMS-791325 is a nonnucleoside inhibitor of hepatitis C virus (HCV) NS5B polymerase with low-nanomolar potency against genotypes 1a (50% effective concentration [EC50], 3 nM) and 1b (EC50, 7 nM) in vitro. BMS-791325 safety, pharmacokinetics, and antiviral activity were evaluated in a double-blind, placebo-controlled, single-ascending-dose study in 24 patients (interferon naive and experienced) with chronic HCV genotype 1 infection, randomized (5:1) to receive a single dose of BMS-791325 (100, 300, 600, or 900 mg) or placebo. The prevalence and phenotype of HCV variants at baseline and specific posttreatment time points were assessed. Antiviral activity was observed in all cohorts, with a mean HCV RNA decline of ≈2.5 log10 copies/ml observed 24 h after a single 300-mg dose. Mean plasma half-life among cohorts was 7 to 9 h; individual 24-hour levels exceeded the protein-adjusted EC90 for genotype 1 at all doses. BMS-791325 was generally well tolerated, with no serious adverse events or discontinuations. Enrichment for resistance variants was not observed at 100 to 600 mg. At 900 mg, variants (P495L/S) associated with BMS-791325 resistance in vitro were transiently observed in one patient, concurrent with an observed HCV RNA decline of 3.4 log10 IU/ml, but were replaced with wild type by 48 h. Single doses of BMS-791325 were well tolerated; demonstrated rapid, substantial, and exposure-related antiviral activity; displayed dose-related increases in exposure; and showed viral kinetic and pharmacokinetic profiles supportive of once- or twice-daily dosing. These results support its further development in combination with other direct-acting antivirals for HCV genotype 1 infection. (This trial has been registered at ClinicalTrials.gov under registration no. NCT00664625.) PMID:24733462

Antiviral activity of lanatoside C against dengue virus infection.

PubMed

Cheung, Yan Yi; Chen, Karen Caiyun; Chen, Huixin; Seng, Eng Khuan; Chu, Justin Jang Hann

2014-11-01

Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19μM for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses. Copyright © 2014 Elsevier B.V. All rights reserved.

The Antiviral Activities and Mechanisms of Marine Polysaccharides: An Overview

PubMed Central

Wang, Wei; Wang, Shi-Xin; Guan, Hua-Shi

2012-01-01

Recently, the studies on the antiviral activities of marine natural products, especially marine polysaccharides, are attracting more and more attention all over the world. Marine-derived polysaccharides and their lower molecular weight oligosaccharide derivatives have been shown to possess a variety of antiviral activities. This paper will review the recent progress in research on the antiviral activities and the mechanisms of these polysaccharides obtained from marine organisms. In particular, it will provide an update on the antiviral actions of the sulfated polysaccharides derived from marine algae including carrageenans, alginates, and fucans, relating to their structure features and the structure–activity relationships. In addition, the recent findings on the different mechanisms of antiviral actions of marine polysaccharides and their potential for therapeutic application will also be summarized in detail. PMID:23235364

Antiviral Action of Hydromethanolic Extract of Geopropolis from Scaptotrigona postica against Antiherpes Simplex Virus (HSV-1).

PubMed

Coelho, Guilherme Rabelo; Mendonça, Ronaldo Zucatelli; Vilar, Karina de Senna; Figueiredo, Cristina Adelaide; Badari, Juliana Cuoco; Taniwaki, Noemi; Namiyama, Gisleine; de Oliveira, Maria Isabel; Curti, Suely Pires; Evelyn Silva, Patricia; Negri, Giuseppina

2015-01-01

The studies on chemical composition and biological activity of propolis had focused mainly on species Apis mellifera L. (Hymenoptera: Apidae). There are few studies about the uncommon propolis collected by stingless bees of the Meliponini tribe known as geopropolis. The geopropolis from Scaptotrigona postica was collected in the region of Barra do Corda, Maranhão state, Brazil. The chemical analysis of hydromethanolic extract of this geopropolis (HMG) was carried out through HPLC-DAD-ESI-MS/MS and the main constituents found were pyrrolizidine alkaloids and C-glycosyl flavones. The presence of alkaloids in extracts of propolis is detected for the first time in this sample. The antiviral activity of HMG was evaluated through viral DNA quantification experiments and electron microscopy experiments. Quantification of viral DNA from herpes virus showed reduction of about 98% in all conditions and concentration tested of the HMG extract. The results obtained were corroborated by transmission electron microscopy, in which the images did not show particle or viral replication complex. The antiviral activity of C-glycosyl flavones was reported for a variety of viruses, being observed at different points in the viral replication. This work is the first report about the antiviral activity of geopropolis from Scaptotrigona postica, in vitro, against antiherpes simplex virus (HSV).

Antiviral Action of Hydromethanolic Extract of Geopropolis from Scaptotrigona postica against Antiherpes Simplex Virus (HSV-1)

PubMed Central

Coelho, Guilherme Rabelo; Mendonça, Ronaldo Zucatelli; Vilar, Karina de Senna; Figueiredo, Cristina Adelaide; Badari, Juliana Cuoco; Taniwaki, Noemi; Namiyama, Gisleine; de Oliveira, Maria Isabel; Curti, Suely Pires; Evelyn Silva, Patricia

2015-01-01

The studies on chemical composition and biological activity of propolis had focused mainly on species Apis mellifera L. (Hymenoptera: Apidae). There are few studies about the uncommon propolis collected by stingless bees of the Meliponini tribe known as geopropolis. The geopropolis from Scaptotrigona postica was collected in the region of Barra do Corda, Maranhão state, Brazil. The chemical analysis of hydromethanolic extract of this geopropolis (HMG) was carried out through HPLC-DAD-ESI-MS/MS and the main constituents found were pyrrolizidine alkaloids and C-glycosyl flavones. The presence of alkaloids in extracts of propolis is detected for the first time in this sample. The antiviral activity of HMG was evaluated through viral DNA quantification experiments and electron microscopy experiments. Quantification of viral DNA from herpes virus showed reduction of about 98% in all conditions and concentration tested of the HMG extract. The results obtained were corroborated by transmission electron microscopy, in which the images did not show particle or viral replication complex. The antiviral activity of C-glycosyl flavones was reported for a variety of viruses, being observed at different points in the viral replication. This work is the first report about the antiviral activity of geopropolis from Scaptotrigona postica, in vitro, against antiherpes simplex virus (HSV). PMID:25861357

Comparison of different methods for extraction of Cinnamomi ramulus: yield, chemical composition and in vitro antiviral activities.

PubMed

Zhou, Jing; Yuan, Xiurong; Li, Ling; Zhang, Tong; Wang, Bing

2017-12-01

Hydrodistillation (HD), supercritical fluid extraction (SFE) and reflux extraction (RE) were applied to obtain Cinnamomi ramulus extracts. The yields, chemical compositions and antiviral activities of the extracts were investigated. Extracts were analysed using gas chromatography-mass spectrometry and the antiviral activities were evaluated using cytopathic effect inhibition assay. HD, SFE and RE afforded 0.376, 1.227 and 5.914% yields, respectively. Cinnamaldehyde (CA), SFE and ethanol extracts exhibited antiviral activities against herpes simplex virus type 1. Moreover, CA and other three extracts had inhibition efficacy against respiratory syncytial virus. The most efficient antiviral activities were obtained with SFE.

Synthesis and antiviral activity of certain second generation methylenecyclopropane nucleosides

PubMed Central

Williams, John D.; Khan, Atiyya R.; Harden, Emma A.; Hartline, Caroll B.; Jefferson, Geraldine M.; Keith, Kathy A.; Prichard, Mark N.; Zemlicka, Jiri; Peet, Norton P.; Bowlin, Terry L.

2012-01-01

A second-generation series of substituted methylenecyclopropane nucleosides (MCPNs) has been synthesized and evaluated for antiviral activity against a panel of human herpesviruses, and for cytotoxicity. Although alkylated 2,6-diaminopurine analogs showed little antiviral activity, the compounds containing ether and thioether substituents at the 6-position of the purine did demonstrate potent and selective antiviral activity against several different human herpesviruses. In the 6-alkoxy series, antiviral activity depended on the length of the ether carbon chain, with the optimum chain length being about four carbon units long. For the corresponding thioethers, compounds containing secondary thioethers were more potent than those with primary thioethers. PMID:22607883

Antiviral activity of aconite alkaloids from Aconitum carmichaelii Debx.

PubMed

Xu, Weiming; Zhang, Min; Liu, Hongwu; Wei, Kun; He, Ming; Li, Xiangyang; Hu, Deyu; Yang, Song; Zheng, Yuguo

2017-12-22

Four diterpenoid alkaloids, namely, (a) hypaconitine, (b) songorine, (c) mesaconitine and (d) aconitine, were isolated from the ethanol root extract of Aconitum carmichaelii Debx. The antiviral activities of these alkaloids against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) were evaluated. Antiviral activity test in vivo showed that compounds a and c, which were C19-diterpenoid alkaloids, showed inactivation efficacy values of 82.4 and 85.6% against TMV at 500 μg/mL, respectively. By contrast, compound c presented inactivation activity of 52.1% against CMV at 500 μg/mL, which was almost equal to that of the commercial Ningnanmycin (87.1% inactivation activity against TMV and 53.8% inactivation activity against CMV). C19-Diterpenoid alkaloids displayed moderate to high antiviral activity against TMV and CMV at 500 μg/mL, dosage plays an important role in antiviral activities. This paper is the first report on the evolution of aconite diterpenoid alkaloids for antiviral activity against CMV.

Ubiquitination of the transcription factor IRF-3 activates RIPA, the apoptotic pathway that protects mice from viral pathogenesis

PubMed Central

Chattopadhyay, Saurabh; Kuzmanovic, Teodora; Zhang, Ying; Wetzel, Jaime L.; Sen, Ganes C.

2016-01-01

SUMMARY The transcription factor IRF-3 mediates cellular antiviral response by inducing the expression of interferon and other antiviral proteins. In RNA-virus infected cells, IRF-3’s transcriptional activation is triggered primarily by RIG-I-like receptors (RLR), which can also activate the RLR-induced IRF-3-mediated pathway of apoptosis (RIPA). Here, we have reported that the pathway of IRF-3 activation in RIPA was independent of and distinct from the known pathway of transcriptional activation of IRF-3. It required linear polyubiquitination of two specific lysine residues of IRF-3 by LUBAC, the linear polyubiquitinating enzyme complex, which bound IRF-3 in signal-dependent fashion. To evaluate the role of RIPA in viral pathogenesis, we engineered a genetically targeted mouse, which expressed a mutant IRF-3 that was RIPA-competent but transcriptionally inert; this single-action IRF-3 could protect mice from lethal viral infection. Our observations indicated that IRF-3-mediated apoptosis of virus-infected cells could be an effective antiviral mechanism, without expression of the interferon-stimulated genes. PMID:27178468

Antiviral activity of acidic polysaccharides from Coccomyxa gloeobotrydiformi, a green alga, against an in vitro human influenza A virus infection.

PubMed

Komatsu, Takayuki; Kido, Nobuo; Sugiyama, Tsuyoshi; Yokochi, Takashi

2013-02-01

The extracts prepared from green algae are reported to possess a variety of biological activities including antioxidant, antitumor and antiviral activities. The acidic polysaccharide fraction from a green alga Coccomyxa gloeobotrydiformi (CmAPS) was isolated and the antiviral action on an in vitro infection of influenza A virus was examined. CmAPS inhibited the growth and yield of all influenza A virus strains tested, such as A/H1N1, A/H2N2, A/H3N2 and A/H1N1 pandemic strains. The 50% inhibitory concentration of CmAPS on the infection of human influenza A virus strains ranged from 26 to 70 µg/mL and the antiviral activity of CmAPS against influenza A/USSR90/77 (H1N1) was the strongest. The antiviral activity of CmAPS was not due to the cytotoxicity against host cells. The antiviral activity of CmAPS required its presence in the inoculation of virus onto MDCK cells. Pretreatment and post-treatment with CmAPS was ineffective for the antiviral activity. CmAPS inhibited influenza A virus-induced erythrocyte hemagglutination and hemolysis. Taken together, CmAPS was suggested to exhibit the anti-influenza virus activity through preventing the interaction of virus and host cells. The detailed antiviral activity of CmAPS is discussed.

Tailoring acyclovir prodrugs with enhanced antiviral activity: rational design, synthesis, human plasma stability and in vitro evaluation.

PubMed

Chayrov, Radoslav L; Stylos, Evgenios K; Chatziathanasiadou, Maria V; Chuchkov, Kiril N; Tencheva, Aleksandra I; Kostagianni, Androniki D; Milkova, Tsenka S; Angelova, Assia L; Galabov, Angel S; Shishkov, Stoyan A; Todorov, Daniel G; Tzakos, Andreas G; Stankova, Ivanka G

2018-05-19

Bile acid prodrugs have served as a viable strategy for refining the pharmaceutical profile of parent drugs through utilizing bile acid transporters. A series of three ester prodrugs of the antiherpetic drug acyclovir (ACV) with the bile acids cholic, chenodeoxycholic and deoxycholic were synthesized and evaluated along with valacyclovir for their in vitro antiviral activity against herpes simplex viruses type 1 and type 2 (HSV-1, HSV-2). The in vitro antiviral activity of the three bile acid prodrugs was also evaluated against Epstein-Barr virus (EBV). Plasma stability assays, utilizing ultra-high performance liquid chromatography coupled with tandem mass spectrometry, in vitro cytotoxicity and inhibitory experiments were conducted in order to establish the biological profile of ACV prodrugs. The antiviral assays demonstrated that ACV-cholate had slightly better antiviral activity than ACV against HSV-1, while it presented an eight-fold higher activity with respect to ACV against HSV-2. ACV-chenodeoxycholate presented a six-fold higher antiviral activity against HSV-2 with respect to ACV. Concerning EBV, the highest antiviral effect was demonstrated by ACV-chenodeoxycholate. Human plasma stability assays revealed that ACV-deoxycholate was more stable than the other two prodrugs. These results suggest that decorating the core structure of ACV with bile acids could deliver prodrugs with amplified antiviral activity.

Antiviral Evaluation of Octadecyloxyethyl Esters of (S)-3-Hydroxy-2-(phosphonomethoxy)propyl Nucleosides Against Herpesviruses and Orthopoxviruses≠

PubMed Central

Valiaeva, Nadejda; Prichard, Mark N.; Buller, R. Mark; Beadle, James R.; Hartline, Caroll B.; Keith, Kathy A.; Schriewer, Jill; Trahan, Julissa; Hostetler, Karl Y.

2009-01-01

Our previous studies showed that esterification of (S)-3-hydroxy-2-(phosphono-methoxy)propyl]adenine (HPMPA) or 1-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]cytosine (HPMPC) with alkoxyalkyl groups such as hexadecyloxypropyl (HDP) or octadecyloxyethyl (ODE) resulted in large increases in antiviral activity and oral bioavailability. The HDP- and ODE- esters of HPMPA were shown to be active in cells infected with human immunodeficiency virus, type 1 (HIV-1), while HPMPA itself was virtually inactive. To explore this approach in greater detail, we synthesized four new compounds in this series, the ODE esters of 9-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]guanine (HPMPG), 1-(S)-[3-hydroxy-2-(phosphono-methoxy)propyl]thymine (HPMPT), 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-2,6-diaminopurine (HPMPDAP) and 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-2-amino-6-cyclopropylaminopurine. (HPMP-cPrDAP) and evaluated their antiviral activity against herpes simplex virus, type 1 (HSV-1), human cytomegalovirus (HCMV), and vaccinia, cowpox and ectromelia. Against HSV-1, subnanomolar EC50 values were observed with ODE-HPMPA and ODE-HPMPC while ODE-HPMPG had intermediate antiviral activity with an EC50 of 40 nanomolar. In HFF cells infected with HCMV, the lowest EC50 values were observed with ODE-HPMPC, 0.9 nanomolar. ODE -HPMPA was highly active with an EC50 of 3 nanomolar, while ODE-HPMPG and ODE-HPMPDAP were also highly active with EC50s of 22 and 77 nanomolar, respectively. Against vaccinia and cowpox viruses, ODE-HPMPG and ODE-HPMPDAP were the most active and selective compounds with EC50 values of 20 to 60 nanomolar and selectivity index values of 600 to 3,500. ODE-HPMPG was also active against ectromelia virus with an EC50 value of 410 nanomolar and a selectivity index value of 166. ODE-HPMPG and ODE-HPMPDAP are proposed for further preclinical evaluation as possible candidates for treatment of HSV, HCMV or orthopoxvirus diseases. PMID:19800369

Evaluation of the Activity of Lamivudine and Zidovudine against Ebola Virus.

PubMed

Cong, Yu; Dyall, Julie; Hart, Brit J; DeWald, Lisa Evans; Johnson, Joshua C; Postnikova, Elena; Zhou, Huanying; Gross, Robin; Rojas, Oscar; Alexander, Isis; Josleyn, Nicole; Zhang, Tengfei; Michelotti, Julia; Janosko, Krisztina; Glass, Pamela J; Flint, Mike; McMullan, Laura K; Spiropoulou, Christina F; Mierzwa, Tim; Guha, Rajarshi; Shinn, Paul; Michael, Sam; Klumpp-Thomas, Carleen; McKnight, Crystal; Thomas, Craig; Eakin, Ann E; O'Loughlin, Kathleen G; Green, Carol E; Catz, Paul; Mirsalis, Jon C; Honko, Anna N; Olinger, Gene G; Bennett, Richard S; Holbrook, Michael R; Hensley, Lisa E; Jahrling, Peter B

2016-01-01

In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 μM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 μg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD.

Design, synthesis, antiviral bioactivity and three-dimensional quantitative structure-activity relationship study of novel ferulic acid ester derivatives containing quinazoline moiety.

PubMed

Wu, Zengxue; Zhang, Jian; Chen, Jixiang; Pan, Jianke; Zhao, Lei; Liu, Dengyue; Zhang, Awei; Chen, Jin; Hu, Deyu; Song, Baoan

2017-10-01

Ferulic acid and quinazoline derivatives possess good antiviral activities. In order to develop novel compounds with high antiviral activities, a series of ferulic acid ester derivatives containing quinazoline were synthesized and evaluated for their antiviral activities. Bioassays indicated that some of the compounds exhibited good antiviral activities in vivo against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). One of the compounds demonstrated significant curative and protective activities against TMV and CMV, with EC 50 values of 162.14, 114.61 and 255.49, 138.81 mg L -1 , respectively, better than those of ningnanmycin (324.51, 168.84 and 373.88, 272.70 mg L -1 ). The values of q 2 and r 2 for comparative molecular field analysis and comparative molecular similarity index analysis in the TMV (0.508, 0.663 and 0.992, 0.930) and CMV (0.530, 0.626 and 0.997, 0.981) models presented good predictive abilities. Some of the title compounds demonstrated good antiviral activities. Three-dimensional quantitative structure-activity relationship models revealed that the antiviral activities depend on steric and electrostatic properties. These results could provide significant structural insights for the design of highly active ferulic acid derivatives. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Structure-Activity Relationships of the Human Immunodeficiency Virus Type 1 Maturation Inhibitor PF-46396.

PubMed

Murgatroyd, Christopher; Pirrie, Lisa; Tran, Fanny; Smith, Terry K; Westwood, Nicholas J; Adamson, Catherine S

2016-09-15

HIV-1 maturation inhibitors are a novel class of antiretroviral compounds that consist of two structurally distinct chemical classes: betulinic acid derivatives and the pyridone-based compound PF-46396. It is currently believed that both classes act by similar modes of action to generate aberrant noninfectious particles via inhibition of CA-SP1 cleavage during Gag proteolytic processing. In this study, we utilized a series of novel analogues with decreasing similarity to PF-46396 to determine the chemical groups within PF-46396 that contribute to antiviral activity, Gag binding, and the relationship between these essential properties. A spectrum of antiviral activity (active, intermediate, and inactive) was observed across the analogue series with respect to CA-SP1 cleavage and HIV-1 (NL4-3) replication kinetics in Jurkat T cells. We demonstrate that selected inactive analogues are incorporated into wild-type (WT) immature particles and that one inactive analogue is capable of interfering with PF-46396 inhibition of CA-SP1 cleavage. Mutations that confer PF-46396 resistance can impose a defective phenotype on HIV-1 that can be rescued in a compound-dependent manner. Some inactive analogues retained the capacity to rescue PF-46396-dependent mutants (SP1-A3V, SP1-A3T, and CA-P157S), implying that they can also interact with mutant Gag. The structure-activity relationships observed in this study demonstrate that (i) the tert-butyl group is essential for antiviral activity but is not an absolute requirement for Gag binding, (ii) the trifluoromethyl group is optimal but not essential for antiviral activity, and (iii) the 2-aminoindan group is important for antiviral activity and Gag binding but is not essential, as its replacement is tolerated. Combinations of antiretroviral drugs successfully treat HIV/AIDS patients; however, drug resistance problems make the development of new mechanistic drug classes an ongoing priority. HIV-1 maturation inhibitors are novel as they target the Gag protein, specifically by inhibiting CA-SP1 proteolytic cleavage. The lack of high-resolution structural information of the CA-SP1 target in Gag has hindered our understanding of the inhibitor-binding pocket and maturation inhibitor mode of action. Therefore, we utilized analogues of the maturation inhibitor PF-46396 as chemical tools to determine the chemical components of PF-46396 that contribute to antiviral activity and Gag binding and the relationship between these essential properties. This is the first study to report structure-activity relationships of the maturation inhibitor PF-46396. PF-46396 is chemically distinct from betulinic acid-derived maturation inhibitors; therefore, our data provide a foundation of knowledge that will aid our understanding of how structurally distinct maturation inhibitors act by similar modes of action. Copyright © 2016 Murgatroyd et al.

Synergistic Interactions between Hepatitis B Virus RNase H Antagonists and Other Inhibitors

PubMed Central

Lomonosova, Elena; Zlotnick, Adam

2016-01-01

ABSTRACT Combination therapies are standard for management of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections; however, no such therapies are established for human hepatitis B virus (HBV). Recently, we identified several promising inhibitors of HBV RNase H (here simply RNase H) activity that have significant activity against viral replication in vitro. Here, we investigated the in vitro antiviral efficacy of combinations of two RNase H inhibitors with the current anti-HBV drug nucleoside analog lamivudine, with HAP12, an experimental core protein allosteric modulator, and with each other. Anti-HBV activities of the compounds were tested in a HepG2-derived cell line by monitoring intracellular core particle DNA levels, and cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. The antiviral efficiencies of the drug combinations were evaluated using the median-effect equation derived from the mass-action law principle and combination index theorem of Chou and Talalay. We found that combinations of two RNase H inhibitors from different chemical classes were synergistic with lamivudine against HBV DNA synthesis. Significant synergism was also observed for the combination of the two RNase H inhibitors. Combinations of RNase H inhibitors with HAP12 had additive antiviral effects. Enhanced cytotoxicity was not observed in the combination experiments. Because of these synergistic and additive effects, the antiviral activity of combinations of RNase H inhibitors with drugs that act by two different mechanisms and with each other can be achieved by administering the compounds in combination at doses below the respective single drug doses. PMID:27956427

Synergistic Interactions between Hepatitis B Virus RNase H Antagonists and Other Inhibitors.

PubMed

Lomonosova, Elena; Zlotnick, Adam; Tavis, John E

2017-03-01

Combination therapies are standard for management of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections; however, no such therapies are established for human hepatitis B virus (HBV). Recently, we identified several promising inhibitors of HBV RNase H (here simply RNase H) activity that have significant activity against viral replication in vitro Here, we investigated the in vitro antiviral efficacy of combinations of two RNase H inhibitors with the current anti-HBV drug nucleoside analog lamivudine, with HAP12, an experimental core protein allosteric modulator, and with each other. Anti-HBV activities of the compounds were tested in a HepG2-derived cell line by monitoring intracellular core particle DNA levels, and cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. The antiviral efficiencies of the drug combinations were evaluated using the median-effect equation derived from the mass-action law principle and combination index theorem of Chou and Talalay. We found that combinations of two RNase H inhibitors from different chemical classes were synergistic with lamivudine against HBV DNA synthesis. Significant synergism was also observed for the combination of the two RNase H inhibitors. Combinations of RNase H inhibitors with HAP12 had additive antiviral effects. Enhanced cytotoxicity was not observed in the combination experiments. Because of these synergistic and additive effects, the antiviral activity of combinations of RNase H inhibitors with drugs that act by two different mechanisms and with each other can be achieved by administering the compounds in combination at doses below the respective single drug doses. Copyright © 2017 American Society for Microbiology.

Antiviral active peptide from oyster

NASA Astrophysics Data System (ADS)

Zeng, Mingyong; Cui, Wenxuan; Zhao, Yuanhui; Liu, Zunying; Dong, Shiyuan; Guo, Yao

2008-08-01

An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster ( Crassostrea gigas) and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight (>10 kDa, 10 5 kDa, 5 1 kDa and <1 kDa) using ultrafiltration membranes and dialysis. The fraction of 10 5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram (HPLC) by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect (CPE). The result shows that the peptide has high inhibitory activity on herpetic virus.

Marine-Natural-Product Development: First Discovery of Nortopsentin Alkaloids as Novel Antiviral, Anti-phytopathogenic-Fungus, and Insecticidal Agents.

PubMed

Ji, Xiaofei; Guo, Jincheng; Liu, Yuxiu; Lu, Aidang; Wang, Ziwen; Li, Yongqiang; Yang, Shaoxiang; Wang, Qingmin

2018-04-25

Nortopsentin alkaloids were found to have potent antiviral, anti-phytopathogenic-fungus, and insecticidal activities for the first time. Antiviral-activity tests revealed that these compounds were very sensitive to substituents, so a series of nortopsentin derivatives were designed, synthesized, and systematically evaluated for their antiviral activities against TMV, their fungicidal activities, and their insecticidal activities on the basis of a structural-diversity-derivation strategy. Compounds 2e (in vivo inactivation-, curative-, and protective-activity inhibitory rates of 50, 59, and 56%, respectively, at 500 μg/mL) and 2k (in vivo inactivation-, curative-, and protective-activity inhibitory rates of 60, 58, and 52%, respectively, at 500 μg/mL), with excellent antiviral activities and good physicochemical properties, emerged as new lead compounds for novel-antiviral-agent development. Further fungicidal-activity tests revealed that these alkaloids displayed broad-spectrum fungicidal activities. Compounds 2f, 2h, and 2j emerged as new lead compounds for antifungal-activity research. Additionally, all the compounds displayed good insecticidal activities against five kinds of insects, including Mythimna separate, Helicoverpa armigera, Ostrinia nubilalis, Plutella xylostella, and Culex pipiens pallens.

A novel peptide with potent and broad-spectrum antiviral activities against multiple respiratory viruses

PubMed Central

Zhao, Hanjun; Zhou, Jie; Zhang, Ke; Chu, Hin; Liu, Dabin; Poon, Vincent Kwok-Man; Chan, Chris Chung-Sing; Leung, Ho-Chuen; Fai, Ng; Lin, Yong-Ping; Zhang, Anna Jin-Xia; Jin, Dong-Yan; Yuen, Kwok-Yung; Zheng, Bo-Jian

2016-01-01

A safe, potent and broad-spectrum antiviral is urgently needed to combat emerging respiratory viruses. In light of the broad antiviral activity of β-defensins, we tested the antiviral activity of 11 peptides derived from mouse β-defensin-4 and found that a short peptide, P9, exhibited potent and broad-spectrum antiviral effects against multiple respiratory viruses in vitro and in vivo, including influenza A virus H1N1, H3N2, H5N1, H7N7, H7N9, SARS-CoV and MERS-CoV. The antiviral activity of P9 was attributed to its high-affinity binding to viral glycoproteins, as well as the abundance of basic amino acids in its composition. After binding viral particles through viral surface glycoproteins, P9 entered into cells together with the viruses via endocytosis and prevented endosomal acidification, which blocked membrane fusion and subsequent viral RNA release. This study has paved the avenue for developing new prophylactic and therapeutic agents with broad-spectrum antiviral activities. PMID:26911565

Nucleic acid polymers: Broad spectrum antiviral activity, antiviral mechanisms and optimization for the treatment of hepatitis B and hepatitis D infection.

PubMed

Vaillant, Andrew

2016-09-01

Antiviral polymers are a well-studied class of broad spectrum viral attachment/entry inhibitors whose activity increases with polymer length and with increased amphipathic (hydrophobic) character. The newest members of this class of compounds are nucleic acid polymers whose activity is derived from the sequence independent properties of phosphorothioated oligonucleotides as amphipathic polymers. Although the antiviral mechanisms and broad spectrum antiviral activity of nucleic acid polymers mirror the functionality of other members of this class, they exert in addition a unique post entry activity in hepatitis B infection which inhibits the release of HBsAg from infected hepatocytes. This review provides a general overview of the antiviral polymer class with a focus on nucleic acid polymers and their development as therapeutic agents for the treatment of hepatitis B/hepatitis D. This article forms part of a symposium in Antiviral Research on ''An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B.''. Copyright © 2016 The Author. Published by Elsevier B.V. All rights reserved.

Detection of the antiviral activity of epicatechin isolated from Salacia crassifolia (Celastraceae) against Mayaro virus based on protein C homology modelling and virtual screening.

PubMed

Ferreira, P G; Ferraz, A C; Figueiredo, J E; Lima, C F; Rodrigues, V G; Taranto, A G; Ferreira, J M S; Brandão, G C; Vieira-Filho, S A; Duarte, L P; de Brito Magalhães, C L; de Magalhães, J C

2018-06-01

Mayaro fever, caused by Mayaro virus (MAYV) is a sub-lethal disease with symptoms that are easily confused with those of dengue fever, except for polyarthralgia, which may culminate in physical incapacitation. Recently, outbreaks of MAYV have been documented in metropolitan areas, and to date, there is no therapy or vaccine available. Moreover, there is no information regarding the three-dimensional structure of the viral proteins of MAYV, which is important in the search for antivirals. In this work, we constructed a three-dimensional model of protein C of MAYV by homology modelling, and this was employed in a manner similar to that of receptors in virtual screening studies to evaluate 590 molecules as prospective antiviral agents. In vitro bioassays were utilized to confirm the potential antiviral activity of the flavonoid epicatechin isolated from Salacia crassifolia (Celastraceae). The virtual screening showed that six flavonoids were promising ligands for protein C. The bioassays showed potent antiviral action of epicatechin, which protected the cells from almost all of the effects of viral infection. An effective concentration (EC 50 ) of 0.247 μmol/mL was observed with a selectivity index (SI) of 7. The cytotoxicity assay showed that epicatechin has low toxicity, with a 50% cytotoxic concentration (CC 50 ) greater than 1.723 µmol/mL. Epicatechin was found to be twice as potent as the reference antiviral ribavirin. Furthermore, a replication kinetics assay showed a strong inhibitory effect of epicatechin on MAYV growth, with a reduction of at least four logs in virus production. Our results indicate that epicatechin is a promising candidate for further testing as an antiviral agent against Mayaro virus and other alphaviruses.

Discovery of novel bovine viral diarrhea inhibitors using structure-based virtual screening on the envelope protein E2

NASA Astrophysics Data System (ADS)

Bollini, Mariela; Leal, Emilse S.; Adler, Natalia S.; Aucar, María G.; Fernández, Gabriela A.; Pascual, María J.; Merwaiss, Fernando; Alvarez, Diego E.; Cavasotto, Claudio N.

2018-03-01

Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus within the family Flaviviridae. BVDV causes both acute and persistent infections in cattle, leading to substantial financial losses to the livestock industry each year. The global prevalence of persistent BVDV infection and the lack of a highly effective antiviral therapy have spurred intensive efforts to discover and develop novel anti-BVDV therapies in the pharmaceutical industry. Antiviral targeting of virus envelope proteins is an effective strategy for therapeutic intervention of viral infections. We performed prospective small-molecule high-throughput docking to identify molecules that likely bind to the region delimited by domains I and II of the envelope protein E2 of BVDV. Several structurally different compounds were purchased or synthesized, and assayed for antiviral activity against BVDV. Five of the selected compounds were active displaying IC50 values in the low- to mid-micromolar range. For these compounds, their possible binding determinants were characterized by molecular dynamics simulations. A common pattern of interactions between active molecules and aminoacid residues in the binding site in E2 was observed. These findings could offer a better understanding of the interaction of BVDV E2 with these inhibitors, as well as benefit the discovery of novel and more potent BVDV antivirals.

The traditional use of Vachellia nilotica for sexually transmitted diseases is substantiated by the antiviral activity of its bark extract against sexually transmitted viruses.

PubMed

Donalisio, Manuela; Cagno, Valeria; Civra, Andrea; Gibellini, Davide; Musumeci, Giuseppina; Rittà, Massimo; Ghosh, Manik; Lembo, David

2018-03-01

Vachellia (Acacia) nilotica and other plants of this genus have been used in traditional medicine of Asian and African countries to treat many disorders, including sexually transmitted diseases, but few studies were performed to validate their anti-microbial and anti-viral activity against sexually transmitted infections. The present study was undertaken to explore whether the ethnomedical use of V.nilotica to treat genital lesions is substantiated by its antiviral activity against the human immunodeficiency virus (HIV), the herpes simplex virus (HSV) and the human papillomavirus (HPV). The antiviral activity of V.nilotica was tested in vitro by virus-specific inhibition assays using HSV-2 strains, sensible or resistant to acyclovir, HIV-1IIIb strain and HPV-16 pseudovirion (PsV). The potential mode of action of extract against HSV-2 and HPV-16 was further investigated by virus inactivation and time-of-addition assays on cell cultures. V.nilotica chloroform, methanolic and water bark extracts exerted antiviral activity against HSV-2 and HPV-16 PsV infections; among these, methanolic extract showed the best EC50s with values of 4.71 and 1.80µg/ml against HSV-2 and HPV-16, respectively, and it was also active against an acyclovir-resistant HSV-2 strain with an EC50 of 6.71µg/ml. By contrast, no suppression of HIV infection was observed. Investigation of the mechanism of action revealed that the methanolic extract directly inactivated the infectivity of the HPV-16 particles, whereas a partial virus inactivation and interference with virus attachment (EC50 of 2.74µg/ml) were both found to contribute to the anti-HSV-2 activity. These results support the traditional use of V.nilotica applied externally for the treatment of genital lesions. Further work remains to be done in order to identify the bioactive components. Copyright © 2017 Elsevier B.V. All rights reserved.

[Reviews on antiviral activity of chemical constituents from plants].

PubMed

Yang, Xian-Feng; Wang, Yu-Li; Xu, Wei-Ren

2008-01-01

This paper reviewed the progress in researches on antiviral activity of chemical constituents from plants in recent years, the antiviral activity and mechanism of action of flavonoids, alkaloids, terpenoids, coumarins and polysaccharoses were sammarszed, provided new leading compound for antivirus new drugs from the plares in prospect.

Expression of feline interferon-alpha subtypes in Esherichia coli, and their antiviral activity and animal species specificity.

PubMed

Taira, Osamu; Suzuki, Makoto; Takeuchi, Yuko; Aramaki, Yoshitaka; Sakurai, Itsuki; Watanabe, Takao; Motokawa, Kenji; Arai, Setsuo; Sato, Hisaaki; Maehara, Nobutoshi

2005-05-01

Two kinds of FeIFN-alpha consisting of 166 amino acids (aa) and 171 aa were expressed in Escherichia coli, and the purified proteins were tested for antiviral activity on homologous and heterologous animal cells. Crude FeIFN induced in feline cells revealed antiviral activity on both homologous and heterologous animal cells. In contrast, both types of recombinant FeIFN-alpha revealed antiviral activity only on the feline cells. All of the FeIFN-alpha subtypes showed high activity to vesicular stomatitis virus, and the three species of feline viruses belonging to different families.

An antibacterial and antiviral peptide produced by Enterococcus mundtii ST4V isolated from soya beans.

PubMed

Todorov, Svetoslav D; Wachsman, Mónica B; Knoetze, Hendriëtte; Meincken, Martina; Dicks, Leon M T

2005-06-01

Enterococcus mundtii ST4V, isolated from soya beans, produces a 3950Da antibacterial peptide active against Gram-positive and Gram-negative bacteria, including Enterococcus faecalis, Streptococcus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae and Staphylococcus aureus. The peptide also inactivated the herpes simplex viruses HSV-1 (strain F) and HSV-2 (strain G), a polio virus (PV3, strain Sabin) and a measles virus (strain MV/BRAZIL/001/91, an attenuated strain of MV). MV, HSV-1 and HSV-2 were 95.5%-99.9% inactivated by peptide ST4V at 400 microg/ml. Monkey kidney Vero cells were not inactivated, even at four times the level peptide ST4V displayed antiviral activity, indicating that the effect was not due to cytotoxicity. Complete inactivation or significant reduction in antimicrobial activity was observed after treatment of peptide ST4V with Proteinase K, pronase, pepsin and trypsin. No change in antimicrobial activity was recorded after treatment with alpha-amylase, suggesting that peptide ST4V was not glycosylated. This is the first description of an antibacterial and antiviral peptide with such broad-spectrum of activity, produced by a lactic acid bacterium.

Autophagy is involved in anti-viral activity of pentagalloylglucose (PGG) against Herpes simplex virus type 1 infection in vitro

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

Pei, Ying, E-mail: peiying-19802@163.com; Chen, Zhen-Ping, E-mail: 530670663@qq.com; Ju, Huai-Qiang, E-mail: 344464448@qq.com

2011-02-11

Research highlights: {yields} We showed PGG has anti-viral activity against Herpes simplex virus type 1 (HSV-1) and can induce autophgy. {yields} Autophagy may be a novel and important mechanism mediating PGG anti-viral activities. {yields} Inhibition of mTOR pathway is an important mechanism of induction of autophagy by PGG. -- Abstract: Pentagalloylglucose (PGG) is a natural polyphenolic compound with broad-spectrum anti-viral activity, however, the mechanisms underlying anti-viral activity remain undefined. In this study, we investigated the effects of PGG on anti-viral activity against Herpes simplex virus type 1 (HSV-1) associated with autophagy. We found that the PGG anti-HSV-1 activity was impairedmore » significantly in MEF-atg7{sup -/-} cells (autophagy-defective cells) derived from an atg7{sup -/-} knockout mouse. Transmission electron microscopy revealed that PGG-induced autophagosomes engulfed HSV-1 virions. The mTOR signaling pathway, an essential pathway for the regulation of autophagy, was found to be suppressed following PGG treatment. Data presented in this report demonstrated for the first time that autophagy induced following PGG treatment contributed to its anti-HSV activity in vitro.« less

Antiviral activity of silymarin against chikungunya virus

PubMed Central

Lani, Rafidah; Hassandarvish, Pouya; Chiam, Chun Wei; Moghaddam, Ehsan; Chu, Justin Jang Hann; Rausalu, Kai; Merits, Andres; Higgs, Stephen; Vanlandingham, Dana; Abu Bakar, Sazaly; Zandi, Keivan

2015-01-01

The mosquito-borne chikungunya virus (CHIKV) causes chikungunya fever, with clinical presentations such as severe back and small joint pain, and debilitating arthritis associated with crippling pains that persist for weeks and even years. Although there are several studies to evaluate the efficacy of drugs against CHIKV, the treatment for chikungunya fever is mainly symptom-based and no effective licensed vaccine or antiviral are available. Here, we investigated the antiviral activity of three types of flavonoids against CHIKV in vitro replication. Three compounds: silymarin, quercetin and kaempferol were evaluated for their in vitro antiviral activities against CHIKV using a CHIKV replicon cell line and clinical isolate of CHIKV of Central/East African genotype. A cytopathic effect inhibition assay was used to determine their activities on CHIKV viral replication and quantitative reverse transcription PCR was used to calculate virus yield. Antiviral activity of effective compound was further investigated by evaluation of CHIKV protein expression using western blotting for CHIKV nsP1, nsP3, and E2E1 proteins. Briefly, silymarin exhibited significant antiviral activity against CHIKV, reducing both CHIKV replication efficiency and down-regulating production of viral proteins involved in replication. This study may have important consequence for broaden the chance of getting the effective antiviral for CHIKV infection. PMID:26078201

ANTIVIRAL ACTIVITY OF DIANTHUS SUPERBUSN L. AGAINST HEPATITIS B VIRUS IN VITRO AND IN VIVO.

PubMed

Li, Wei-Guo; Wang, He-Qun

2016-01-01

Hepatitis is a viral infection of hepatitis B virus (HBV). Limitations of drug used in the management of it opens the interest related to alternative medicine. The given study deals with the antiviral activity of Dianthus superbusn L. (DSL) against HBV in vitro & in vivo . In vitro study liver cell line HepG2.2.15 was used by transinfected it with HBV. Cytotoxicity stduy was performed by using different concentrations of DSL such as 50, 100, 200, 500 & 1000 μg/ml. Anti HBV activity of DSL was estimated by assesing the concentration of HBsAg and HbeAg in cell culture medium by using ELISA. Whereas in vivo study was performed on ducklings and antiviral activity of DSL (100, 200, 400 mg/kg) was confirmed by estimating the serum concentration of HBV DNA and histopathology study of hepatocytes in HBV infected ducklings. Result of the study suggested that >500 μg/ml concentration of hydroalcoholic extract of DSL was found tobe cytotoxic. It was also observed that DSL significantly ( p <0.05) reduces the concentration of antigenes in cell culture media as per the concentration and days of treatment dependent. Moreover in vivo study confirms the anti viral activity of DSL (200 & 400 mg/kg) as it significantly ( p <0.05) decreases the serum concenetration of HBV DNA in HBV infected dukling compared to control group. Histopathology study was also reveals the hepatprotective effect of DSL in HBV infected ducklings. The given study concludes the antiviral activity DSL against HBV by in vitro and in vivo models.

Antiviral screening of forty-two Egyptian medicinal plants.

PubMed

Soltan, Maha Mohamed; Zaki, Adel Kamal

2009-10-29

Egyptian medicinal plants are well known by their diverse uses in traditional folk medicine to cure various ailments including infectious diseases. Forty-two Egyptian medicinal plant species were selected from local market and were subjected to antiviral screening bioassay to investigate and to evaluate their biological activities. Hydro-alcoholic extracts of each species were separately prepared and tested against three viruses: herpes simplex-1 virus (HSV), poliomyelitis-1 virus (POLIO) and vesicular stomatitis virus (VSV). The antiviral activity were determined by means of the end point titration technique (EPTT) that depends on the ability of plant extract dilutions to inhibit the produced cytopathogenic effect (CPE) and expressed as reduction factor (Rf) of the viral titer. Achillea fragrantissima, Jasonia montana and Globularia arabica are found to have antiviral activity against POLIO in a concentration dependent manner at complete non-toxic concentration range 10-100 microg/ml (Rf 10(6)), 10-100 microg/ml (Rf 10(5)) and 50-100 microg/ml (Rf 10(4)), respectively while Tanacetum sinaicum are found to have moderate antiviral activity against POLIO at concentration of 50-100 microg/ml (Rf 10(2)). Ephedra alata and Moringa peregrina are found to have antiviral activity against HSV (Rf 10(4)). Also, the results revealed that Capparis sinaica, Tamarix nilotica and Cyperus rotundus are found to have virucidal effect against HSV. All the forty-two plant species are found to have no reliable antiviral activity against VSV. The specific indications claimed by the traditional healers are confirmed by antiviral test.

Synergistic Effects of Sulfated Polysaccharides from Mexican Seaweeds against Measles Virus

PubMed Central

Morán-Santibañez, Karla; Cruz-Suárez, Lucia Elizabeth; Ricque-Marie, Denis; Robledo, Daniel; Freile-Pelegrín, Yolanda; Peña-Hernández, Mario A.; Rodríguez-Padilla, Cristina

2016-01-01

Sulfated polysaccharides (SPs) extracted from five seaweed samples collected or cultivated in Mexico (Macrocystis pyrifera, Eisenia arborea, Pelvetia compressa, Ulva intestinalis, and Solieria filiformis) were tested in this study in order to evaluate their effect on measles virus in vitro. All polysaccharides showed antiviral activity (as measured by the reduction of syncytia formation) and low cytotoxicity (MTT assay) at inhibitory concentrations. SPs from Eisenia arborea and Solieria filiformis showed the highest antiviral activities (confirmed by qPCR) and were selected to determine their combined effect. Their synergistic effect was observed at low concentrations (0.0274 μg/mL and 0.011 μg/mL of E. arborea and S. filiformis SPs, resp.), which exhibited by far a higher inhibitory effect (96% syncytia reduction) in comparison to the individual SP effects (50% inhibition with 0.275 μg/mL and 0.985 μg/mL of E. arborea and S. filiformis, resp.). Time of addition experiments and viral penetration assays suggest that best activities of these SPs occur at different stages of infection. The synergistic effect would allow reducing the treatment dose and toxicity and minimizing or delaying the induction of antiviral resistance; sulfated polysaccharides of the tested seaweed species thus appear as promising candidates for the development of natural antiviral agents. PMID:27419139

Mst1 shuts off cytosolic antiviral defense through IRF3 phosphorylation

PubMed Central

Meng, Fansen; Zhou, Ruyuan; Wu, Shiying; Zhang, Qian; Jin, Qiuheng; Zhou, Yao; Plouffe, Steven W.; Liu, Shengduo; Song, Hai; Xia, Zongping; Zhao, Bin; Ye, Sheng; Feng, Xin-Hua; Guan, Kun-Liang; Zou, Jian

2016-01-01

Cytosolic RNA/DNA sensing elicits primary defense against viral pathogens. Interferon regulatory factor 3 (IRF3), a key signal mediator/transcriptional factor of the antiviral-sensing pathway, is indispensible for interferon production and antiviral defense. However, how the status of IRF3 activation is controlled remains elusive. Through a functional screen of the human kinome, we found that mammalian sterile 20-like kinase 1 (Mst1), but not Mst2, profoundly inhibited cytosolic nucleic acid sensing. Mst1 associated with IRF3 and directly phosphorylated IRF3 at Thr75 and Thr253. This Mst1-mediated phosphorylation abolished activated IRF3 homodimerization, its occupancy on chromatin, and subsequent IRF3-mediated transcriptional responses. In addition, Mst1 also impeded virus-induced activation of TANK-binding kinase 1 (TBK1), further attenuating IRF3 activation. As a result, Mst1 depletion or ablation enabled an enhanced antiviral response and defense in cells and mice. Therefore, the identification of Mst1 as a novel physiological negative regulator of IRF3 activation provides mechanistic insights into innate antiviral defense and potential antiviral prevention strategies. PMID:27125670

Functional evaluation of synthetic flavonoids and chalcones for potential antiviral and anticancer properties.

PubMed

Mateeva, Nelly; Eyunni, Suresh V K; Redda, Kinfe K; Ononuju, Ucheze; Hansberry, Tony D; Aikens, Cecilia; Nag, Anita

2017-06-01

Flavonoids, stilbenes, and chalcones are plant secondary metabolites that often possess diverse biological activities including anti-inflammatory, anti-cancer, and anti-viral activities. The wide range of bioactivities poses a challenge to identify their targets. Here, we studied a set of synthetically generated flavonoids and chalcones to evaluate for their biological activity, and compared similarly substituted flavonoids and chalcones. Substituted chalcones, but not flavonoids, showed inhibition of viral translation without significantly affecting viral replication in cells infected with hepatitis C virus (HCV). We suggest that the chalcones used in this study inhibit mammalian target of rapamycin (mTOR) pathway by ablating phosphorylation of ribosomal protein 6 (rps6), and also the kinase necessary for phosphorylating rps6 in Huh7.5 cells (pS6K1). In addition, selected chalcones showed inhibition of growth in Ishikawa, MCF7, and MDA-MB-231 cells resulting an IC 50 of 1-6µg/mL. When similarly substituted flavonoids were used against the same set of cancer cells, we did not observe any inhibitory effect. Together, we report that chalcones show potential for anti-viral and anti-cancer activities compared to similarly substituted flavonoids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Macromolecular Antiviral Agents against Zika, Ebola, SARS, and Other Pathogenic Viruses.

PubMed

Schandock, Franziska; Riber, Camilla Frich; Röcker, Annika; Müller, Janis A; Harms, Mirja; Gajda, Paulina; Zuwala, Kaja; Andersen, Anna H F; Løvschall, Kaja Borup; Tolstrup, Martin; Kreppel, Florian; Münch, Jan; Zelikin, Alexander N

2017-12-01

Viral pathogens continue to constitute a heavy burden on healthcare and socioeconomic systems. Efforts to create antiviral drugs repeatedly lag behind the advent of pathogens and growing understanding is that broad-spectrum antiviral agents will make strongest impact in future antiviral efforts. This work performs selection of synthetic polymers as novel broadly active agents and demonstrates activity of these polymers against Zika, Ebola, Lassa, Lyssa, Rabies, Marburg, Ebola, influenza, herpes simplex, and human immunodeficiency viruses. Results presented herein offer structure-activity relationships for these pathogens in terms of their susceptibility to inhibition by polymers, and for polymers in terms of their anionic charge and hydrophobicity that make up broad-spectrum antiviral agents. The identified leads cannot be predicted based on prior data on polymer-based antivirals and represent promising candidates for further development as preventive microbicides. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

LGP2 Synergy with MDA5 in RLR-Mediated RNA Recognition and Antiviral Signaling

PubMed Central

Bruns, Annie M.; Horvath, Curt M.

2015-01-01

Mammalian cells have the ability to recognize virus infection and mount a powerful antiviral response. Pattern recognition receptor proteins detect molecular signatures of virus infection and activate antiviral signaling. The RIG-I-like receptor (RLR) proteins are expressed in the cytoplasm of nearly all cells and specifically recognize virus-derived RNA species as a molecular feature discriminating the pathogen from the host. The RLR family is composed of three homologous proteins, RIG-I, MDA5, and LGP2. All RLRs have the ability to detect virus-derived dsRNA and hydrolyze ATP, but display individual differences in enzymatic activity, intrinsic ability to recognize RNA, and mechanisms of activation. Emerging evidence suggests that MDA5 and RIG-I utilize distinct mechanisms to form oligomeric complexes along dsRNA. Aligning of their signaling domains creates a platform capable of propagating and amplifying antiviral signaling responses. LGP2 with intact ATP hydrolysis is critical for the MDA5-mediated antiviral response, but LGP2 lacks the domains essential for activation of antiviral signaling, leaving the role of LGP2 in antiviral signaling unclear. Recent studies revealed a mechanistic basis of synergy between LGP2 and MDA5 leading to enhanced antiviral signaling. This review briefly summarizes the RLR system, and focuses on the relationship between LGP2 and MDA5, describing in detail how these two proteins work together to detect foreign RNA and generate a fully functional antiviral response. PMID:25794939

Contribution of herpesvirus specific CD8 T cells to anti-viral T cell response in humans.

PubMed

Sandalova, Elena; Laccabue, Diletta; Boni, Carolina; Tan, Anthony T; Fink, Katja; Ooi, Eng Eong; Chua, Robert; Shafaeddin Schreve, Bahar; Ferrari, Carlo; Bertoletti, Antonio

2010-08-19

Herpesviruses infect most humans. Their infections can be associated with pathological conditions and significant changes in T cell repertoire but evidences of symbiotic effects of herpesvirus latency have never been demonstrated. We tested the hypothesis that HCMV and EBV-specific CD8 T cells contribute to the heterologous anti-viral immune response. Volume of activated/proliferating virus-specific and total CD8 T cells was evaluated in 50 patients with acute viral infections: 20 with HBV, 12 with Dengue, 12 with Influenza, 3 with Adenovirus infection and 3 with fevers of unknown etiology. Virus-specific (EBV, HCMV, Influenza) pentamer+ and total CD8 T cells were analyzed for activation (CD38/HLA-DR), proliferation (Ki-67/Bcl-2(low)) and cytokine production. We observed that all acute viral infections trigger an expansion of activated/proliferating CD8 T cells, which differs in size depending on the infection but is invariably inflated by CD8 T cells specific for persistent herpesviruses (HCMV/EBV). CD8 T cells specific for other non-related non persistent viral infection (i.e. Influenza) were not activated. IL-15, which is produced during acute viral infections, is the likely contributing mechanism driving the selective activation of herpesvirus specific CD8 T cells. In addition we were able to show that herpesvirus specific CD8 T cells displayed an increased ability to produce the anti-viral cytokine interferon-gamma during the acute phase of heterologous viral infection. Taken together, these data demonstrated that activated herpesvirus specific CD8 T cells inflate the activated/proliferating CD8 T cells population present during acute viral infections in human and can contribute to the heterologous anti-viral T cell response.

TRIM25 Enhances the Antiviral Action of Zinc-Finger Antiviral Protein (ZAP)

PubMed Central

Lau, Zerlina; Cheung, Pamela; Schneider, William M.; Bozzacco, Leonia; Buehler, Eugen; Takaoka, Akinori; Rice, Charles M.; Felsenfeld, Dan P.; MacDonald, Margaret R.

2017-01-01

The host factor and interferon (IFN)-stimulated gene (ISG) product, zinc-finger antiviral protein (ZAP), inhibits a number of diverse viruses by usurping and intersecting with multiple cellular pathways. To elucidate its antiviral mechanism, we perform a loss-of-function genome-wide RNAi screen to identify cellular cofactors required for ZAP antiviral activity against the prototype alphavirus, Sindbis virus (SINV). In order to exclude off-target effects, we carry out stringent confirmatory assays to verify the top hits. Important ZAP-liaising partners identified include proteins involved in membrane ion permeability, type I IFN signaling, and post-translational protein modification. The factor contributing most to the antiviral function of ZAP is TRIM25, an E3 ubiquitin and ISG15 ligase. We demonstrate here that TRIM25 interacts with ZAP through the SPRY domain, and TRIM25 mutants lacking the RING or coiled coil domain fail to stimulate ZAP’s antiviral activity, suggesting that both TRIM25 ligase activity and its ability to form oligomers are critical for its cofactor function. TRIM25 increases the modification of both the short and long ZAP isoforms by K48- and K63-linked polyubiquitin, although ubiquitination of ZAP does not directly affect its antiviral activity. However, TRIM25 is critical for ZAP’s ability to inhibit translation of the incoming SINV genome. Taken together, these data uncover TRIM25 as a bona fide ZAP cofactor that leads to increased ZAP modification enhancing its translational inhibition activity. PMID:28060952

TRIM25 Enhances the Antiviral Action of Zinc-Finger Antiviral Protein (ZAP).

PubMed

Li, Melody M H; Lau, Zerlina; Cheung, Pamela; Aguilar, Eduardo G; Schneider, William M; Bozzacco, Leonia; Molina, Henrik; Buehler, Eugen; Takaoka, Akinori; Rice, Charles M; Felsenfeld, Dan P; MacDonald, Margaret R

2017-01-01

The host factor and interferon (IFN)-stimulated gene (ISG) product, zinc-finger antiviral protein (ZAP), inhibits a number of diverse viruses by usurping and intersecting with multiple cellular pathways. To elucidate its antiviral mechanism, we perform a loss-of-function genome-wide RNAi screen to identify cellular cofactors required for ZAP antiviral activity against the prototype alphavirus, Sindbis virus (SINV). In order to exclude off-target effects, we carry out stringent confirmatory assays to verify the top hits. Important ZAP-liaising partners identified include proteins involved in membrane ion permeability, type I IFN signaling, and post-translational protein modification. The factor contributing most to the antiviral function of ZAP is TRIM25, an E3 ubiquitin and ISG15 ligase. We demonstrate here that TRIM25 interacts with ZAP through the SPRY domain, and TRIM25 mutants lacking the RING or coiled coil domain fail to stimulate ZAP's antiviral activity, suggesting that both TRIM25 ligase activity and its ability to form oligomers are critical for its cofactor function. TRIM25 increases the modification of both the short and long ZAP isoforms by K48- and K63-linked polyubiquitin, although ubiquitination of ZAP does not directly affect its antiviral activity. However, TRIM25 is critical for ZAP's ability to inhibit translation of the incoming SINV genome. Taken together, these data uncover TRIM25 as a bona fide ZAP cofactor that leads to increased ZAP modification enhancing its translational inhibition activity.

ANTIVIRAL ACTIVITY OF DIANTHUS SUPERBUSN L. AGAINST HEPATITIS B VIRUS IN VITRO AND IN VIVO

PubMed Central

Li, Wei-Guo; Wang, He-Qun

2016-01-01

Background: Hepatitis is a viral infection of hepatitis B virus (HBV). Limitations of drug used in the management of it opens the interest related to alternative medicine. The given study deals with the antiviral activity of Dianthus superbusn L. (DSL) against HBV in vitro & in vivo. Material and Methods: In vitro study liver cell line HepG2.2.15 was used by transinfected it with HBV. Cytotoxicity stduy was performed by using different concentrations of DSL such as 50, 100, 200, 500 & 1000 μg/ml. Anti HBV activity of DSL was estimated by assesing the concentration of HBsAg and HbeAg in cell culture medium by using ELISA. Whereas in vivo study was performed on ducklings and antiviral activity of DSL (100, 200, 400 mg/kg) was confirmed by estimating the serum concentration of HBV DNA and histopathology study of hepatocytes in HBV infected ducklings. Result: Result of the study suggested that >500 μg/ml concentration of hydroalcoholic extract of DSL was found tobe cytotoxic. It was also observed that DSL significantly (p<0.05) reduces the concentration of antigenes in cell culture media as per the concentration and days of treatment dependent. Moreover in vivo study confirms the anti viral activity of DSL (200 & 400 mg/kg) as it significantly (p<0.05) decreases the serum concenetration of HBV DNA in HBV infected dukling compared to control group. Histopathology study was also reveals the hepatprotective effect of DSL in HBV infected ducklings. Conclusion: The given study concludes the antiviral activity DSL against HBV by in vitro and in vivo models. PMID:28487893

Antiviral Lectins: Selective Inhibitors of Viral Entry

PubMed Central

Mitchell, Carter A.; Ramessar, Koreen; O’Keefe, Barry R.

2017-01-01

Many natural lectins have been reported to have antiviral activity. As some of these have been put forward as potential development candidates for preventing or treating viral infections, we have set out in this review to survey the literature on antiviral lectins. The review groups lectins by structural class and class of source organism we also detail their carbohydrate specificity and their reported antiviral activities. The review concludes with a brief discussion of several of the pertinent hurdles that heterologous proteins must clear to be useful clinical candidates and cites examples where such studies have been reported for antiviral lectins. Though the clearest path currently being followed is the use of antiviral lectins as anti-HIV microbicides via topical mucosal administration, some investigators have also found systemic efficacy against acute infections following subcutaneous administration. PMID:28322922

Spectroscopic investigation of herpes simplex viruses infected cells and their response to antiviral therapy

NASA Astrophysics Data System (ADS)

Erukhimovitch, Vitaly; Talyshinsky, Marina; Souprun, Yelena; Huleihel, Mahmoud

2006-07-01

In the present study, we used microscopic Fourier transform infrared spectroscopy (FTIR) to evaluate the antiviral activity of known antiviral agents against herpes viruses. The antiviral activity of Caffeic acid phenethyl ester (CAPE) (which is an active compound of propolis) against herpes simplex type 1 and 2 was examined in cell culture. The advantage of microscopic FTIR spectroscopy over conventional FTIR spectroscopy is that it facilitates inspection of restricted regions of cell culture or tissue. Our results showed significant spectral differences at early stages of infection between infected and non-infected cells, and between infected cells treated with the used antiviral agent and those not treated. In infected cells, there was a considerable increase in phosphate levels. Our results show that treatment with used antiviral agent considerably abolish the spectral changes induced by the viral infection. In addition, it is possible to track by FTIR microscopy method the deferential effect of various doses of the drug.

Antiviral activity of lauryl gallate against animal viruses.

PubMed

Hurtado, Carolina; Bustos, Maria Jose; Sabina, Prado; Nogal, Maria Luisa; Granja, Aitor G; González, Maria Eugenia; Gónzalez-Porqué, Pedro; Revilla, Yolanda; Carrascosa, Angel L

2008-01-01

Antiviral compounds are needed in the control of many animal and human diseases. We analysed the effect of the antitumoural drug lauryl gallate on the infectivity of the African swine fever virus among other DNA (herpes simplex and vaccinia) and RNA (influenza, porcine transmissible gastroenteritis and Sindbis) viruses, paying attention to its effect on the viability of the corresponding host cells. Viral production was strongly inhibited in different cell lines at non-toxic concentrations of the drug (1-10 microM), reducing the titres 3->5 log units depending on the multiplicity of infection. In our model system (African swine fever virus in Vero cells), the addition of the drug 1 h before virus adsorption completely abolished virus productivity in a one-step growth virus cycle. Interestingly, no inhibitory effect was observed when lauryl gallate was added after 5-8 h post-infection. Both cellular and viral DNA synthesis and late viral transcription were inhibited by the drug; however, the early viral protein synthesis and the virus-mediated increase of p53 remained unaffected. Activation of the apoptotic effector caspase-3 was not detected after lauryl gallate treatment of Vero cells. Furthermore, the presence of the drug abrogated the activation of this protease induced by the virus infection. Lauryl gallate is a powerful antiviral agent against several pathogens of clinical and veterinary importance. The overall results indicate that a cellular factor or function might be the target of the antiviral action of alkyl gallates.

Rigid amphipathic fusion inhibitors demonstrate antiviral activity against African swine fever virus.

PubMed

Hakobyan, Astghik; Galindo, Inmaculada; Nañez, Almudena; Arabyan, Erik; Karalyan, Zaven; Chistov, Alexey A; Streshnev, Philipp P; Korshun, Vladimir A; Alonso, Covadonga; Zakaryan, Hovakim

2018-01-01

Rigid amphipathic fusion inhibitors (RAFIs) are a family of nucleoside derivatives that inhibit the infectivity of several enveloped viruses by interacting with virion envelope lipids and inhibiting fusion between viral and cellular membranes. Here we tested the antiviral activity of two RAFIs, 5-(Perylen-3-ylethynyl)-arabino-uridine (aUY11) and 5-(Perylen-3-ylethynyl)uracil-1-acetic acid (cm1UY11) against African swine fever virus (ASFV), for which no effective vaccine is available. Both compounds displayed a potent, dose-dependent inhibitory effect on ASFV infection in Vero cells. The major antiviral effect was observed when aUY11 and cm1UY11 were added at early stages of infection and maintained during the complete viral cycle. Furthermore, virucidal assay revealed a significant extracellular anti-ASFV activity for both compounds. We also found decrease in the synthesis of early and late viral proteins in Vero cells treated with cm1UY11. Finally, the inhibitory effect of aUY11 and cm1UY11 on ASFV infection in porcine alveolar macrophages was confirmed. Overall, our study has identified novel anti-ASFV compounds with potential for future therapeutic developments.

Anti-viral role of toll like receptor 4 in hepatitis B virus infection: An in vitro study.

PubMed

Das, Dipanwita; Sarkar, Neelakshi; Sengupta, Isha; Pal, Ananya; Saha, Debraj; Bandopadhyay, Manikankana; Das, Chandrima; Narayan, Jimmy; Singh, Shivram Prasad; Chakravarty, Runu

2016-12-21

Toll like receptors plays a significant anti-viral role in different infections. The aim of this study was to look into the role of toll like receptor 4 (TLR4) in hepatitis B virus (HBV) infection. Real time PCR was used to analyze the transcription of TLR4 signaling molecules, cell cycle regulators and HBV DNA viral load after triggering the HepG2.2.15 cells with TLR4 specific ligand. Nuclear factor (NF)-κB translocation on TLR4 activation was analyzed using microscopic techniques. Protein and cell cycle analysis was done using Western Blot and FACS respectively. The present study shows that TLR4 activation represses HBV infection. As a result of HBV suppression, there are several changes in host factors which include partial release in G1/S cell cycle arrest and changes in host epigenetic marks. Finally, it was observed that anti-viral action of TLR4 takes place through the NF-κB pathway. The study shows that TLR4 activation in HBV infection brings about changes in hepatocyte microenvironment and can be used for developing a promising therapeutic target in future.

Quercetin and quercetin 3-O-glycosides from Bauhinia longifolia (Bong.) Steud. show anti-Mayaro virus activity.

PubMed

dos Santos, Alda E; Kuster, Ricardo M; Yamamoto, Kristie A; Salles, Tiago S; Campos, Renata; de Meneses, Marcelo D F; Soares, Márcia R; Ferreira, Davis

2014-03-28

The arthropod-borne Mayaro virus (MAYV) causes 'Mayaro fever', a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Recently, MAYV has attracted attention due to its likely urbanization. Currently, there are no licensed drugs against most mosquito-transmitted viruses. Here, we investigated the in vitro anti-MAYV activity of the flavonoids quercetin and its derivatives from the Brazilian shrub Bauhinia longifolia (Bong.) Steud. Flavonoids were purified by chromatographic fractionation from leaf extracts of B. longifolia and chemically identified as quercetin and quercetin glycosides using spectroscopic techniques. Cytotoxicity of purified flavonoids and of EtOAc- and n-BuOH-containing flavonoid mixtures was measured by the dye-uptake assay while their antiviral activity was evaluated by a virus yield inhibition assay. The following flavonoids were purified from B. longifolia leaves: non-glycosylated quercetin and its glycosides guaijaverin, quercitrin, isoquercitrin, and hyperin. EtOAc and n-BuOH fractions containing these flavonoids demonstrated the highest antiviral activity of all tested substances, while quercetin had the highest antiviral activity amongst purified flavonoids. Quercetin, EtOAc, or n-BuOH fractions inhibited MAYV production by more than 90% at 25 μg/mL, displaying a stronger antiviral effect than the licensed antiviral ribavirin. A mixture of the isomers isoquercitrin and hyperin had a modest antiviral effect (IC90 = 104.9), while guaijaverin and quercitrin did not show significant antiviral activity. B. longifolia is a good source of flavonoids with anti-Mayaro virus activity. This is the first report of the activity of quercetin and its derivatives against an alphavirus.

Quercetin and quercetin 3-O-glycosides from Bauhinia longifolia (Bong.) Steud. show anti-Mayaro virus activity

PubMed Central

2014-01-01

Background The arthropod-borne Mayaro virus (MAYV) causes ‘Mayaro fever’, a disease of medical significance, primarily affecting individuals in permanent contact with forested areas in tropical South America. Recently, MAYV has attracted attention due to its likely urbanization. Currently, there are no licensed drugs against most mosquito-transmitted viruses. Here, we investigated the in vitro anti-MAYV activity of the flavonoids quercetin and its derivatives from the Brazilian shrub Bauhinia longifolia (Bong.) Steud. Methods Flavonoids were purified by chromatographic fractionation from leaf extracts of B. longifolia and chemically identified as quercetin and quercetin glycosides using spectroscopic techniques. Cytotoxicity of purified flavonoids and of EtOAc- and n-BuOH-containing flavonoid mixtures was measured by the dye-uptake assay while their antiviral activity was evaluated by a virus yield inhibition assay. Results The following flavonoids were purified from B. longifolia leaves: non-glycosylated quercetin and its glycosides guaijaverin, quercitrin, isoquercitrin, and hyperin. EtOAc and n-BuOH fractions containing these flavonoids demonstrated the highest antiviral activity of all tested substances, while quercetin had the highest antiviral activity amongst purified flavonoids. Quercetin, EtOAc, or n-BuOH fractions inhibited MAYV production by more than 90% at 25 μg/mL, displaying a stronger antiviral effect than the licensed antiviral ribavirin. A mixture of the isomers isoquercitrin and hyperin had a modest antiviral effect (IC90 = 104.9), while guaijaverin and quercitrin did not show significant antiviral activity. Conclusions B. longifolia is a good source of flavonoids with anti-Mayaro virus activity. This is the first report of the activity of quercetin and its derivatives against an alphavirus. PMID:24678592

Perspective of Use of Antiviral Peptides against Influenza Virus

PubMed Central

Skalickova, Sylvie; Heger, Zbynek; Krejcova, Ludmila; Pekarik, Vladimir; Bastl, Karel; Janda, Jozef; Kostolansky, Frantisek; Vareckova, Eva; Zitka, Ondrej; Adam, Vojtech; Kizek, Rene

2015-01-01

The threat of a worldwide influenza pandemic has greatly increased over the past decade with the emergence of highly virulent avian influenza strains. The increased frequency of drug-resistant influenza strains against currently available antiviral drugs requires urgent development of new strategies for antiviral therapy, too. The research in the field of therapeutic peptides began to develop extensively in the second half of the 20th century. Since then, the mechanisms of action for several peptides and their antiviral prospect received large attention due to the global threat posed by viruses. Here, we discussed the therapeutic properties of peptides used in influenza treatment. Peptides with antiviral activity against influenza can be divided into three main groups. First, entry blocker peptides such as a Flupep that interact with influenza hemagglutinin, block its binding to host cells and prevent viral fusion. Second, several peptides display virucidal activity, disrupting viral envelopes, e.g., Melittin. Finally, a third set of peptides interacts with the viral polymerase complex and act as viral replication inhibitors such as PB1 derived peptides. Here, we present a review of the current literature describing the antiviral activity, mechanism and future therapeutic potential of these influenza antiviral peptides. PMID:26492266

Value of the dorsal cutaneous guinea pig model in selecting topical antiviral formulations for the treatment of recurrent herpes simplex type 1 disease.

PubMed

Poli, G; Dall'Ara, P; Binda, S; Santus, G; Poli, A; Cocilovo, A; Ponti, W

2001-01-01

Recurrent herpes simplex labialis represents a disease still difficult to treat, despite the availability of many established antiviral drugs used in clinical research since 30 years ago. Although differences between the human disease and that obtained in experimental animal suggest caution in predicting an effective clinical response from the experimental results, some of the animal models seem to be useful in optimising the topical formulation of single antiviral drugs. In the present work the dorsal cutaneous guinea pig model was used to compare 5 different topical antiviral formulations with clinical promise (active molecule: 5% w/w micronized aciclovir, CAS 59277-89-3), using both roll-on and lipstick application systems. The aim being to evaluate which vehicle (water, oil, low melting and high melting fatty base) and application system (roll-on, lipstick) enhances the skin penetration and the antiviral activity of the drug, after an experimental intradermal infection with Herpes simplex virus type 1 (HSV-1). As reference, a commercial formulation (5% aciclovir ointment) was used. The cumulative results of this study showed that the formulation A, containing 5% aciclovir in an aqueous base in a roll-on application system, has the better antiviral efficacy in reducing the severity of cutaneous lesions and the viral titer; among the lipsticks preparations, the formulation D, containing 5% aciclovir in a low melting fatty base, demonstrates a very strong antiviral activity, though slightly less than formulation A. This experimental work confirms the validity of the dorsal cutaneous guinea pig model as a rapid and efficient method to compare the antiviral efficacy of new formulations, with clinical promise, to optimise the topical formulation of the active antiviral drugs.

Antiviral and cytotoxic activities of some Indonesian plants.

PubMed

Lohézic-Le Dévéhat, F; Bakhtiar, A; Bézivin, C; Amoros, M; Boustie, J

2002-08-01

Ten methanolic extracts from eight Indonesian medicinal plants were phytochemically screened and evaluated for antiviral (HSV-1 and Poliovirus) and cytotoxic activities on murine and human cancer lines (3LL, L1210, K562, U251, DU145, MCF-7). Besides Melastoma malabathricum (Melastomataceae), the Indonesian Loranthaceae species among which Elytranthe tubaeflora, E. maingayi, E. globosa and Scurrula ferruginea exhibited attractive antiviral and cytotoxic activities. Piper aduncum (Piperaceae) was found active on Poliovirus. S. ferruginea was selected for further studies because of its activity on the U251 glioblastoma cells.

The enzymatic activity of CEM15/Apobec-3G is essential for the regulation of the infectivity of HIV-1 virion but not a sole determinant of its antiviral activity.

PubMed

Shindo, Keisuke; Takaori-Kondo, Akifumi; Kobayashi, Masayuki; Abudu, Aierken; Fukunaga, Keiko; Uchiyama, Takashi

2003-11-07

Human immunodeficiency virus, type 1 (HIV-1) Vif protein plays an essential role in the regulation of the infectivity of HIV-1 virion. Vif functions to counteract an anti-HIV-1 cellular factor in non-permissive cells, CEM15/Apobec-3G, which shares a cytidine deaminase motif. CEM15/Apobec-3G deaminates dC to dU in the minus strand DNA of HIV-1, resulting in G to A hypermutation in the plus strand DNA. In this study, we have done the mutagenesis analysis on two cytidine deaminase motifs in CEM15/Apobec-3G and examined their antiviral functions as well as the DNA editing activity. Point mutations in the C-terminal active site such as E259Q and C291A almost completely abrogated the antiviral function, while those in the N-terminal active site such as E67Q and C100A retained this activity to a lesser extent as compared with that of the wild type. The DNA editing activities of E67Q and E259Q mutants were both retained but impaired to the same extent. This indicates that the enzymatic activity of this protein is essential but not a sole determinant of the antiviral activity. Furthermore, all the deletion mutants tested in this study lost the antiviral activity because of the loss of the activity for dimerization, suggesting that the entire protein structure is necessary for the antiviral function.

Nucleobases and corresponding nucleosides display potent antiviral activities against dengue virus possibly through viral lethal mutagenesis.

PubMed

Qiu, Li; Patterson, Steven E; Bonnac, Laurent F; Geraghty, Robert J

2018-04-01

Dengue virus affects millions of people worldwide each year. To date, there is no drug for the treatment of dengue-associated disease. Nucleosides are effective antivirals and work by inhibiting the accurate replication of the viral genome. Nucleobases offer a cheaper alternative to nucleosides for broad antiviral applications. Metabolic activation of nucleobases involves condensation with 5-phosphoribosyl-1-pyrophosphate to give the corresponding nucleoside-5'-monophosphate. This could provide an alternative to phosphorylation of a nucleoside, a step that is often rate limiting and inefficient in activation of nucleosides. We evaluated more than 30 nucleobases and corresponding nucleosides for their antiviral activity against dengue virus. Five nucleobases and two nucleosides were found to induce potent antiviral effects not previously described. Our studies further revealed that nucleobases were usually more active with a better tissue culture therapeutic index than their corresponding nucleosides. The development of viral lethal mutagenesis, an antiviral approach that takes into account the quasispecies behavior of RNA viruses, represents an exciting prospect not yet studied in the context of dengue replication. Passage of the virus in the presence of the nucleobase 3a (T-1105) and corresponding nucleoside 3b (T-1106), favipiravir derivatives, induced an increase in apparent mutations, indicating lethal mutagenesis as a possible antiviral mechanism. A more concerted and widespread screening of nucleobase libraries is a very promising approach to identify dengue virus inhibitors including those that may act as viral mutagens.

Depletion of elongation initiation factor 4E binding proteins by CRISPR/Cas9 enhances the antiviral response in porcine cells.

PubMed

Ramírez-Carvajal, Lisbeth; Singh, Neetu; de los Santos, Teresa; Rodríguez, Luis L; Long, Charles R

2016-01-01

Type I interferons (IFNs) are key mediators of the innate antiviral response in mammalian cells. Elongation initiation factor 4E binding proteins (4E-BPs) are translational controllers of interferon regulatory factor 7 (IRF-7), the "master regulator" of IFN transcription. Previous studies have suggested that mouse cells depleted of 4E-BPs are more sensitive to IFNβ treatment and had lower viral loads as compared to wild type (WT) cells. However, such approach has not been tested as an antiviral strategy in livestock species. In this study, we tested the antiviral activity of porcine cells depleted of 4E-BP1 by a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) genome engineering system. We found that 4E-BP1 knockout (KO) porcine cells had increased expression of IFNα and β, IFN stimulated genes, and significant reduction in vesicular stomatitis virus titer as compare to WT cells. No phenotypical changes associated with CRISPR/Cas9 manipulation were observed in 4E-BP1 KO cells. This work highlights the use of the CRISPR/Cas9 system to enhance the antiviral response in porcine cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Studies on Antiviral and Immuno-Regulation Activity of Low Molecular Weight Fucoidan from Laminaria japonica

NASA Astrophysics Data System (ADS)

Sun, Taohua; Zhang, Xinhui; Miao, Ying; Zhou, Yang; Shi, Jie; Yan, Meixing; Chen, Anjin

2018-06-01

The antiviral activity in vitro and in vivo and the effect of the immune system of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica (LMW fucoidans) were investigated in order to examine the possible mechanism. In vitro, I-type influenza virus, adenovirus and Parainfluenza virus I were used to infect Hep-2, Hela and MDCK cells, respectively. And 50% tissue culture infective dose was calculated to detect the antiviral activity of two LMW fucoidans. The results indicated that compared with the control group, 2 kinds of LMW fucoidans had remarkable antiviral activity in vitro in middle and high doses, while at low doses, the antiviral activity of 2 kinds of LMW fucoidans was not statistically different from that in the blank control group. And there was no statistically difference between two LMW fucoidans in antiviral activity. In vivo, LMW fucoidans could prolong the survival time of virus-infected mice, and could improve the lung index of virus-infected mice significantly, which have statistical differences with the control group significantly ( p < 0.01). However, the survival time of the two LMW fucoidans was not statistically significant ( p > 0.05). In this study, it was shown that both of two LMW fucoidans (LF1, LF2) could increase the thymus index, spleen index, phagocytic index, phagocytosis coefficient and half hemolysin value in middle and high doses, which suggested that LMW fucoidans could play an antiviral role by improving the quality of immune organs, improving immune cell phagocytosis and humoral immunity.

Screening for Antiviral Activities of Isolated Compounds from Essential Oils

PubMed Central

Astani, Akram; Reichling, Jürgen; Schnitzler, Paul

2011-01-01

Essential oil of star anise as well as phenylpropanoids and sesquiterpenes, for example, trans-anethole, eugenol, β-eudesmol, farnesol, β-caryophyllene and β-caryophyllene oxide, which are present in many essential oils, were examined for their antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro. Antiviral activity was analyzed by plaque reduction assays and mode of antiviral action was determined by addition of the drugs to uninfected cells, to the virus prior to infection or to herpesvirus-infected cells. Star anise oil reduced viral infectivity by >99%, phenylpropanoids inhibited HSV infectivity by about 60–80% and sesquiterpenes suppressed herpes virus infection by 40–98%. Both, star anise essential oil and all isolated compounds exhibited anti-HSV-1 activity by direct inactivation of free virus particles in viral suspension assays. All tested drugs interacted in a dose-dependent manner with herpesvirus particles, thereby inactivating viral infectivity. Star anise oil, rich in trans-anethole, revealed a high selectivity index of 160 against HSV, whereas among the isolated compounds only β-caryophyllene displayed a high selectivity index of 140. The presence of β-caryophyllene in many essential oils might contribute strongly to their antiviral ability. These results indicate that phenylpropanoids and sesquiterpenes present in essential oils contribute to their antiviral activity against HSV. PMID:20008902

Activation of RIG-I-like Receptor Signal Transduction

PubMed Central

Bruns, Annie; Horvath, Curt M.

2011-01-01

Mammalian cells have the ability to recognize virus infection and mount a powerful antiviral response. Pattern recognition receptor proteins detect molecular signatures of virus infection and activate antiviral signaling cascades. The RIG-I-like receptors are cytoplasmic DExD/H box proteins that can specifically recognize virus-derived RNA species as a molecular feature discriminating the pathogen from the host. The RIG-I-like receptor family is composed of three homologous proteins, RIG-I, MDA5, and LGP2. All of these proteins can bind double-stranded RNA species with varying affinities via their conserved DExD/H box RNA helicase domains and C-terminal regulatory domains. The recognition of foreign RNA by the RLRs activates enzymatic functions and initiates signal transduction pathways resulting in the production of antiviral cytokines and the establishment of a broadly effective cellular antiviral state that protects neighboring cells from infection and triggers innate and adaptive immune systems. The propagation of this signal via the interferon antiviral system has been studied extensively, while the precise roles for enzymatic activities of the RNA helicase domain in antiviral responses are only beginning to be elucidated. Here, current models for RLR ligand recognition and signaling are reviewed. PMID:22066529

Antiviral Activity of Porcine Interferon Regulatory Factor 1 against Swine Viruses in Cell Culture.

PubMed

Li, Yongtao; Chang, Hongtao; Yang, Xia; Zhao, Yongxiang; Chen, Lu; Wang, Xinwei; Liu, Hongying; Wang, Chuanqing; Zhao, Jun

2015-11-17

Interferon regulatory factor 1 (IRF1), as an important transcription factor, is abundantly induced upon virus infections and participates in host antiviral immune responses. However, the roles of porcine IRF1 (poIRF1) in host antiviral defense remain poorly understood. In this study, we determined that poIRF1 was upregulated upon infection with viruses and distributed in nucleus in porcine PK-15 cells. Subsequently, we tested the antiviral activities of poIRF1 against several swine viruses in cells. Overexpression of poIRF1 can efficiently suppress the replication of viruses, and knockdown of poIRF1 promotes moderately viral replication. Interestingly, overexpression of poIRF1 enhances dsRNA-induced IFN-β and IFN-stimulated response element (ISRE) promoter activation, whereas knockdown of poIRF1 cannot significantly affect the activation of IFN-β promoter induced by RNA viruses. This study suggests that poIRF1 plays a significant role in cellular antiviral response against swine viruses, but might be dispensable for IFN-β induction triggered by RNA viruses in PK-15 cells. Given these results, poIRF1 plays potential roles in cellular antiviral responses against swine viruses.

Cytotoxic, Virucidal, and Antiviral Activity of South American Plant and Algae Extracts

PubMed Central

Faral-Tello, Paula; Mirazo, Santiago; Dutra, Carmelo; Pérez, Andrés; Geis-Asteggiante, Lucía; Frabasile, Sandra; Koncke, Elina; Davyt, Danilo; Cavallaro, Lucía; Heinzen, Horacio; Arbiza, Juan

2012-01-01

Herpes simplex virus type 1 (HSV-1) infection has a prevalence of 70% in the human population. Treatment is based on acyclovir, valacyclovir, and foscarnet, three drugs that share the same mechanism of action and of which resistant strains have been isolated from patients. In this aspect, innovative drug therapies are required. Natural products offer unlimited opportunities for the discovery of antiviral compounds. In this study, 28 extracts corresponding to 24 plant species and 4 alga species were assayed in vitro to detect antiviral activity against HSV-1. Six of the methanolic extracts inactivated viral particles by direct interaction and 14 presented antiviral activity when incubated with cells already infected. Most interesting antiviral activity values obtained are those of Limonium brasiliense, Psidium guajava, and Phyllanthus niruri, which inhibit HSV-1 replication in vitro with 50% effective concentration (EC50) values of 185, 118, and 60 μg/mL, respectively. For these extracts toxicity values were calculated and therefore selectivity indexes (SI) obtained. Further characterization of the bioactive components of antiviral plants will pave the way for the discovery of new compounds against HSV-1. PMID:22619617

Retinoid X receptor α attenuates host antiviral response by suppressing type I interferon

PubMed Central

Ma, Feng; Liu, Su-Yang; Razani, Bahram; Arora, Neda; Li, Bing; Kagechika, Hiroyuki; Tontonoz, Peter; Núñez, Vanessa; Ricote, Mercedes; Cheng, Genhong

2015-01-01

The retinoid X receptor α (RXRα), a key nuclear receptor in metabolic processes, is down-regulated during host antiviral response. However, the roles of RXRα in host antiviral response are unknown. Here we show that RXRα overexpression or ligand activation increases host susceptibility to viral infections in vitro and in vivo, while Rxra −/− or antagonist treatment reduces infection by the same viruses. Consistent with these functional studies, ligand activation of RXR inhibits the expression of antiviral genes including type I interferon (IFN) and Rxra −/− macrophages produce more IFNβ than WT macrophages in response to polyI:C stimulation. Further results indicate that ligand activation of RXR suppresses the nuclear translocation of β-catenin, a co-activator of IFNβ enhanceosome. Thus, our studies have uncovered a novel RXR-dependent innate immune regulatory pathway, suggesting that the downregulation of RXR expression or RXR antagonist treatment benefits host antiviral response, whereas RXR agonist treatment may increase the risk of viral infections. PMID:25417649

TRIM E3 ligases in HIV infection: can these intrinsic immunity factors be harnessed for novel vaccines or therapies?

PubMed

Ndung'u, Thumbi

2011-01-01

Tripartite motif-containing (TRIM) E3 ligases are a recently identified family of proteins with potent antiviral activity in mammalian cells. The prototype TRIM E3 ligase, TRIM5α was initially identified as a species-specific antiviral restriction factor but subsequent studies suggest some antiviral activity by several TRIM E3 ligases in human cells. However, the mechanisms of antiviral activity by these proteins and their transcriptional, translational and post-translational regulation are poorly understood. Furthermore, the contribution of TRIM E3 ligases to relative resistance or viral control in vivo is largely unknown. Emerging data from our laboratory and other groups suggests that these proteins may have antiviral activity in vivo and contribute to HIV pathogenesis. Considering the significant difficulties so far encountered in developing an effective HIV vaccine and with the use of antiretroviral therapies, it will be important to further investigate the potential of TRIM E3 ligases as novel prophylactics or therapies.

Assessment of Inhibition of Ebola Virus Progeny Production by Antiviral Compounds.

PubMed

Falzarano, Darryl

2017-01-01

Assessment of small molecule compounds against filoviruses, such as Ebola virus, has identified numerous compounds that appear to have antiviral activity and should presumably be further investigated in animal efficacy trials. However, despite the many compounds that are purported to have good antiviral activity in in vitro studies, there are few instances where any efficacy has been reported in nonhuman primate models. Many of the high-throughput screening assays use reporter systems that only recapitulate a portion of the virus life cycle, while other assays only assess antiviral activity at relatively early time points. Moreover, many assays do not assess virus progeny production. A more in-depth evaluation of small numbers of test compounds is useful to economize resources and to generate higher quality antiviral hits. Assessing virus progeny production as late as 5 days post-infection allows for the elimination of compounds that have initial antiviral effects that are not sustained or where the virus rapidly develops resistance. While this eliminates many potential lead compounds that may be worthy of further structure-activity relationship (SAR) development, it also quickly excludes compounds that in their current form are unlikely to be effective in animal models. In addition, the inclusion of multiple assays that assess both cell viability and cell cytotoxicity, via different mechanisms, provides a more thorough assessment to exclude compounds that are not direct-acting antivirals.

Antiviral Activity of Peanut (Arachis hypogaea L.) Skin Extract Against Human Influenza Viruses.

PubMed

Makau, Juliann Nzembi; Watanabe, Ken; Mohammed, Magdy M D; Nishida, Noriyuki

2018-05-30

The high propensity of influenza viruses to develop resistance to antiviral drugs necessitates the continuing search for new therapeutics. Peanut skins, which are low-value byproducts of the peanut industry, are known to contain high levels of polyphenols. In this study, we investigated the antiviral activity of ethanol extracts of peanut skins against various influenza viruses using cell-based assays. Extracts with a higher polyphenol content exhibited higher antiviral activities, suggesting that the active components are the polyphenols. An extract prepared from roasted peanut skins effectively inhibited the replication of influenza virus A/WSN/33 with a half maximal inhibitory concentration of 1.3 μg/mL. Plaque assay results suggested that the extract inhibits the early replication stages of the influenza virus. It demonstrated activity against both influenza type A and type B viruses. Notably, the extract exhibited a potent activity against a clinical isolate of the 2009 H1N1 pandemic, which had reduced sensitivity to oseltamivir. Moreover, a combination of peanut skin extract with the anti-influenza drugs, oseltamivir and amantadine, synergistically increased their antiviral activity. These data demonstrate the potential application of peanut skin extract in the development of new therapeutic options for influenza management.

Isolation of pyropheophorbide a from the leaves of Atalantia monophylla (ROXB.) CORR. (Rutaceae) as a possible antiviral active principle against herpes simplex virus type 2.

PubMed

Chansakaow, S; Ruangrungsi, N; Ishikawa, T

1996-07-01

Antiviral activity-guided isolation studies on the leaves of Atalantia monophylla (ROXB.) CORR. (Rutaceae) led to the identification of pyropheophorbide a (1), a simple chlorin derivative, from the chloroform extract (fr. B) as a possible antiviral active principle against herpes simplex virus type 2 (HSV-2). Pyropheophorbide a methyl ester (2) was also isolated from the hexane extract (fr. A).

Antiviral drug research proposal activity.

PubMed

Injaian, Lisa; Smith, Ann C; Shipley, Jennifer German; Marbach-Ad, Gili; Fredericksen, Brenda

2011-01-01

The development of antiviral drugs provides an excellent example of how basic and clinical research must be used together in order to achieve the final goal of treating disease. A Research Oriented Learning Activity was designed to help students to better understand how basic and clinical research can be combined toward a common goal. Through this project students gained a better understanding of the process of scientific research and increased their information literacy in the field of virology. The students worked as teams to research the many aspects involved in the antiviral drug design process, with each student becoming an "expert" in one aspect of the project. The Antiviral Drug Research Proposal (ADRP) culminated with students presenting their proposals to their peers and local virologists in a poster session. Assessment data showed increased student awareness and knowledge of the research process and the steps involved in the development of antiviral drugs as a result of this activity.

Potential Antiviral Agents from Marine Fungi: An Overview

PubMed Central

Zorofchian Moghadamtousi, Soheil; Nikzad, Sonia; Abdul Kadir, Habsah; Abubakar, Sazaly; Zandi, Keivan

2015-01-01

Biodiversity of the marine world is only partially subjected to detailed scientific scrutiny in comparison to terrestrial life. Life in the marine world depends heavily on marine fungi scavenging the oceans of lifeless plants and animals and entering them into the nutrient cycle by. Approximately 150 to 200 new compounds, including alkaloids, sesquiterpenes, polyketides, and aromatic compounds, are identified from marine fungi annually. In recent years, numerous investigations demonstrated the tremendous potential of marine fungi as a promising source to develop new antivirals against different important viruses, including herpes simplex viruses, the human immunodeficiency virus, and the influenza virus. Various genera of marine fungi such as Aspergillus, Penicillium, Cladosporium, and Fusarium were subjected to compound isolation and antiviral studies, which led to an illustration of the strong antiviral activity of a variety of marine fungi-derived compounds. The present review strives to summarize all available knowledge on active compounds isolated from marine fungi with antiviral activity. PMID:26204947

Antiviral Drug Research Proposal Activity †

PubMed Central

Injaian, Lisa; Smith, Ann C.; Shipley, Jennifer German; Marbach-Ad, Gili; Fredericksen, Brenda

2011-01-01

The development of antiviral drugs provides an excellent example of how basic and clinical research must be used together in order to achieve the final goal of treating disease. A Research Oriented Learning Activity was designed to help students to better understand how basic and clinical research can be combined toward a common goal. Through this project students gained a better understanding of the process of scientific research and increased their information literacy in the field of virology. The students worked as teams to research the many aspects involved in the antiviral drug design process, with each student becoming an “expert” in one aspect of the project. The Antiviral Drug Research Proposal (ADRP) culminated with students presenting their proposals to their peers and local virologists in a poster session. Assessment data showed increased student awareness and knowledge of the research process and the steps involved in the development of antiviral drugs as a result of this activity. PMID:23653735

Inhibition of Prostaglandin E2 Production by Anti-inflammatory Hypericum perforatum Extracts and Constituents in RAW264.7 Mouse Macrophage Cells

PubMed Central

Hammer, Kimberly D. P.; Hillwig, Matthew L.; Solco, Avery K. S.; Dixon, Philip M.; Delate, Kathleen; Murphy, Patricia A.; Wurtele, Eve S.; Birt, Diane F.

2008-01-01

Hypericum perforatum (Hp) is commonly known for its antiviral, antidepressant, and cytotoxic properties, but traditionally Hp was also used to treat inflammation. In this study, the anti-inflammatory activity and cytotoxicity of different Hp extractions and accessions and constituents present within Hp extracts were characterized. In contrast to the antiviral activity of Hp, the anti-inflammatory activity observed with all Hp extracts was light-independent. When pure constituents were tested, the flavonoids, amentoflavone, hyperforin, and light-activated pseudohypericin, displayed anti-inflammatory activity, albeit at concentrations generally higher than the amount present in the Hp extracts. Constituents that were present in the Hp extracts at concentrations that inhibited the production of prostaglandin E2 (PGE2) were pseudohypericin and hyperforin, suggesting that they are the primary anti-inflammatory constituents along with the flavonoids, and perhaps the interactions of these constituents and other unidentified compounds are important for the anti-inflammatory activity of the Hp extracts. PMID:17696442

Antiviral Activity of Polyacrylic and Polymethacrylic Acids

PubMed Central

De Somer, P.; De Clercq, E.; Billiau, A.; Schonne, E.; Claesen, M.

1968-01-01

Polyacrylic acid (PAA) and polymethacrylic acid (PMAA) were investigated for their antiviral properties in tissue culture. Compared to other related polyanions, as dextran sulfate, polystyrene sulfonate, polyvinyl sulfate, and polyphloroglucinol phosphate, PAA and PMAA were found to be significantly more antivirally active and less cytotoxic. PMAA added 24 hr prior to virus inoculation inhibited viral growth most efficiently but it was still effective when added 3 hr after infection. Neither a direct irreversible action on the virus nor inhibition of virus penetration into the cell could explain the antiviral activity of PMAA. PMAA inhibited the adsorption of the virus to the host cell and suppressed the one-cycle viral synthesis in tissue cultures inoculated with infectious RNA. PMID:4302187

Antibacterial, antifungal, and antiviral activities of the lipophylic extracts of Pistacia vera.

PubMed

Ozçelik, Berrin; Aslan, Mustafa; Orhan, Ilkay; Karaoglu, Taner

2005-01-01

In the present study, antibacterial, antifungal, and antiviral properties of 15 lipohylic extracts obtained from different parts (leaf, branch, stem, kernel, shell skins, seeds) of Pistacia vera were screened against both standard and the isolated strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. parapsilosis by microdilution method. Both Herpes simplex (DNA) and Parainfluenza viruses (RNA) were used for the determination of antiviral activity of the P. vera extracts by using Vero cell line. Ampicilline, ofloxocine, ketoconazole, fluconazole, acyclovir and oseltamivir were used as the control agents. The extracts showed little antibacterial activity between the range of 128-256 microg/ml concentrations whereas they had noticeable antifungal activity at the same concentrations. Kernel and seed extracts showed significant antiviral activity compared to the rest of the extracts as well as the controls.

Broad spectrum antiviral agent ribavirin inhibits capping of mRNA

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

Goswami, B.B.; Borek, E.; Sharma, O.K.

1979-08-13

Ribavirin (1-..beta..-D-ribofuranosyl-1,2,4-triazole-3-carboxamide) is a broad spectrum antiviral substance active against a wide range of both DNA and RNA viruses. It is, however, virtually inactive against polio virus. Its pharmacological mechanism of action was obscure. A possible common target for a chemotherapeutic agent in both DNA and RNA viruses is the capping reaction of mRNAs which inter alia involves the formation of a guanine pyrophosphate structure at the 5' terminus by mRNA guanylyl transferase. We have observed that Ribavirin triphosphate is a potent competitive inhibitor of the capping guanylation of viral mRNA. This finding could account for the antiviral potency ofmore » the drug against both DNA and RNA viruses and its ineffectiveness against a virus in which the mRNAs derived from them are not capped.« less

Triazole nucleoside derivatives bearing aryl functionalities on the nucleobases show antiviral and anticancer activity.

PubMed

Xia, Yi; Qu, Fanqi; Peng, Ling

2010-08-01

Synthetic nucleoside mimics are important candidates in the searing for antiviral and anticancer drugs. Ribavirin, the first antiviral nucleoside drug, is unique in its antiviral activity with mutilple modes of action, which are mainly due to its special triazole heterocycle as nucleobase. Additionally, introducing aromatic functionalities to the nucleobase is able to confer novel mechanisms of action for nucleoside mimics. With the aim to combine the special characteristics of unnatural triazole heterocycles with those of the appended aromatic groups on the nucleobases, novel 1,2,4-triazole nucleoside analogs bearing aromatic moieties were designed and developed. The present short review summarizes the molecular design, chemical synthesis and biological activity of these triazole nucleoside analogs. Indeed, the discovery of antiviral and anticancer activities shown by these triazole nucleosides as well as the new mechanism underlying the biological activity by one of the anticancer leads has validated the rationale for molecular design and impacted us to further explore the concept with the aim of developing structurally novel nucleoside drug candidates with new modes of action.

The Effect of Trim5 Polymorphisms on the Clinical Course of HIV-1 Infection

PubMed Central

van Manen, Daniëlle; Rits, Maarten A. N; Beugeling, Corrine; van Dort, Karel; Schuitemaker, Hanneke; Kootstra, Neeltje A

2008-01-01

The antiviral factor tripartite interaction motif 5α (Trim5α) restricts a broad range of retroviruses in a species-specific manner. Although human Trim5α is unable to block HIV-1 infection in human cells, a modest inhibition of HIV-1 replication has been reported. Recently two polymorphisms in the Trim5 gene (H43Y and R136Q) were shown to affect the antiviral activity of Trim5α in vitro. In this study, participants of the Amsterdam Cohort studies were screened for polymorphisms at amino acid residue 43 and 136 of the Trim5 gene, and the potential effects of these polymorphisms on the clinical course of HIV-1 infection were analyzed. In agreement with the reported decreased antiviral activity of Trim5α that contains a Y at amino acid residue 43 in vitro, an accelerated disease progression was observed for individuals who were homozygous for the 43Y genotype as compared to individuals who were heterozygous or homozygous for the 43H genotype. A protective effect of the 136Q genotype was observed but only after the emergence of CXCR4-using (X4) HIV-1 variants and when a viral load of 104.5 copies per ml plasma was used as an endpoint in survival analysis. Interestingly, naive CD4 T cells, which are selectively targeted by X4 HIV-1, revealed a significantly higher expression of Trim5α than memory CD4 T cells. In addition, we observed that the 136Q allele in combination with the −2GG genotype in the 5′UTR was associated with an accelerated disease progression. Thus, polymorphisms in the Trim5 gene may influence the clinical course of HIV-1 infection also underscoring the antiviral effect of Trim5α on HIV-1 in vivo. PMID:18248091

Public health management of antiviral drugs during the 2009 H1N1 influenza pandemic: a survey of local health departments in California

PubMed Central

2012-01-01

Background The large-scale deployment of antiviral drugs from the Strategic National Stockpile during the 2009 H1N1 influenza response provides a unique opportunity to study local public health implementation of the medical countermeasure dispensing capability in a prolonged event of national significance. This study aims to describe the range of methods used by local health departments (LHDs) in California to manage antiviral activities and to gain a better understanding of the related challenges experienced by health departments and their community partners. Methods This research employed a mixed-methods approach. First, a multi-disciplinary focus group of pandemic influenza planners from key stakeholder groups in California was convened in order to generate ideas and identify critical themes related to the local implementation of antiviral activities during the H1N1 influenza response. These qualitative data informed the development of a web-based survey, which was distributed to all 61 LHDs in California for the purpose of assessing the experiences of a representative sample of local health agencies in a large region. Results Forty-four LHDs participated in this study, representing 72% of the local public health agencies in California. While most communities dispensed a modest number of publicly purchased antivirals, LHDs nevertheless drew on their previous work and engaged in a number of antiviral activities, including: acquiring, allocating, distributing, dispensing, tracking, developing guidance, and communicating to the public and clinical community. LHDs also identified specific antiviral challenges presented by the H1N1 pandemic, including: reconciling multiple sources and versions of antiviral guidance, determining appropriate uses and recipients of publicly purchased antivirals, and staffing shortages. Conclusions The 2009 H1N1 influenza pandemic presented an unusual opportunity to learn about the role of local public health in the management of antiviral response activities during a real public health emergency. Results of this study offer an important descriptive account of LHD management of publicly purchased antivirals, and provide practitioners, policy makers, and academics with a practice-based assessment of these events. The issues raised and the challenges faced by LHDs should be leveraged to inform public health planning for future pandemics and other emergency events that require medical countermeasure dispensing activities. PMID:22276659

Recent progress in the antiviral activity and mechanism study of pentacyclic triterpenoids and their derivatives.

PubMed

Xiao, Sulong; Tian, Zhenyu; Wang, Yufei; Si, Longlong; Zhang, Lihe; Zhou, Demin

2018-05-01

Viral infections cause many serious human diseases with high mortality rates. New drug-resistant strains are continually emerging due to the high viral mutation rate, which makes it necessary to develop new antiviral agents. Compounds of plant origin are particularly interesting. The pentacyclic triterpenoids (PTs) are a diverse class of natural products from plants composed of three terpene units. They exhibit antitumor, anti-inflammatory, and antiviral activities. Oleanolic, betulinic, and ursolic acids are representative PTs widely present in nature with a broad antiviral spectrum. This review focuses on the recent literatures in the antiviral efficacy of this class of phytochemicals and their derivatives. In addition, their modes of action are also summarized. © 2018 Wiley Periodicals, Inc.

The innate immune sensor LGP2 activates antiviral signaling by regulating MDA5-RNA interaction and filament assembly

PubMed Central

Bruns, Annie M.; Leser, George P.; Lamb, Robert A.; Horvath, Curt M.

2014-01-01

SUMMARY Cytoplasmic pattern recognition receptors detect non-self RNAs during virus infections and initiate antiviral signaling. One receptor, MDA5, possesses essential signaling domains, but weak RNA binding. A second receptor, LGP2, rapidly detects diverse dsRNA species, but lacks signaling domains. Accumulating evidence suggests LGP2 and MDA5 work together to detect viral RNA and generate a complete antiviral response, but the basis for their cooperation has been elusive. Experiments presented here address this gap in antiviral signaling, revealing that LGP2 assists MDA5-RNA interactions leading to enhanced MDA5-mediated antiviral signaling. LGP2 increases the initial rate of MDA5-RNA interaction and regulates MDA5 filament assembly, resulting in the formation of more numerous, shorter MDA5 filaments that are shown to generate equivalent or greater signaling activity in vivo than the longer filaments containing only MDA5. These findings provide a mechanism for LGP2 co-activation of MDA5 and a biological context for MDA5-RNA filaments in antiviral responses. PMID:25127512

Antiviral activity and specific modes of action of bacterial prodigiosin against Bombyx mori nucleopolyhedrovirus in vitro.

PubMed

Zhou, Wei; Zeng, Cheng; Liu, RenHua; Chen, Jie; Li, Ru; Wang, XinYan; Bai, WenWen; Liu, XiaoYuan; Xiang, TingTing; Zhang, Lin; Wan, YongJi

2016-05-01

Prodigiosin, the tripyrrole red pigment, is a bacterial secondary metabolite with multiple bioactivities; however, the antiviral activity has not been reported yet. In the present study, we found the antiviral activity of bacterial prodigiosin on Bombyx mori nucleopolyhedrovirus (BmNPV)-infected cells in vitro, with specific modes of action. Prodigiosin at nontoxic concentrations selectively killed virus-infected cells, inhibited viral gene transcription, especially viral early gene ie-1, and prevented virus-mediated membrane fusion. Under prodigiosin treatment, both progeny virus production and viral DNA replication were significantly inhibited. Fluorescent assays showed that prodigiosin predominantly located in cytoplasm which suggested it might interact with cytoplasm factors to inhibit virus replication. In conclusion, the present study clearly indicates that prodigiosin possesses significant antiviral activity against BmNPV.

Chemical Space Mapping and Structure-Activity Analysis of the ChEMBL Antiviral Compound Set.

PubMed

Klimenko, Kyrylo; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

2016-08-22

Curation, standardization and data fusion of the antiviral information present in the ChEMBL public database led to the definition of a robust data set, providing an association of antiviral compounds to seven broadly defined antiviral activity classes. Generative topographic mapping (GTM) subjected to evolutionary tuning was then used to produce maps of the antiviral chemical space, providing an optimal separation of compound families associated with the different antiviral classes. The ability to pinpoint the specific spots occupied (responsibility patterns) on a map by various classes of antiviral compounds opened the way for a GTM-supported search for privileged structural motifs, typical for each antiviral class. The privileged locations of antiviral classes were analyzed in order to highlight underlying privileged common structural motifs. Unlike in classical medicinal chemistry, where privileged structures are, almost always, predefined scaffolds, privileged structural motif detection based on GTM responsibility patterns has the decisive advantage of being able to automatically capture the nature ("resolution detail"-scaffold, detailed substructure, pharmacophore pattern, etc.) of the relevant structural motifs. Responsibility patterns were found to represent underlying structural motifs of various natures-from very fuzzy (groups of various "interchangeable" similar scaffolds), to the classical scenario in medicinal chemistry (underlying motif actually being the scaffold), to very precisely defined motifs (specifically substituted scaffolds).

Design, synthesis, antiviral activity and three-dimensional quantitative structure-activity relationship study of novel 1,4-pentadien-3-one derivatives containing the 1,3,4-oxadiazole moiety.

PubMed

Gan, Xiuhai; Hu, Deyu; Li, Pei; Wu, Jian; Chen, Xuewen; Xue, Wei; Song, Baoan

2016-03-01

1,4-Pentadien-3-one and 1,3,4-oxadiazole derivatives possess good antiviral activities, and their substructure units are usually used in antiviral agent design. In order to discover novel molecules with high antiviral activities, a series of 1,4-pentadien-3-one derivatives containing the 1,3,4-oxadiazole moiety were designed and synthesised. Bioassays showed that most of the title compounds exhibited good inhibitory activities against tobacco mosaic virus (TMV) in vivo. The compound 8f possessing the best protective activity against TMV had an EC50 value of 135.56 mg L(-1) , which was superior to that of ribavirin (435.99 mg L(-1) ). Comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) techniques were used in three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of protective activities, with values of q(2) and r(2) for the CoMFA and CoMSIA models of 0.751 and 0.775 and 0.936 and 0.925 respectively. Compound 8k with higher protective activity (EC50 = 123.53 mg L(-1) ) according to bioassay was designed and synthesised on the basis of the 3D-QSAR models. Some of the title compounds displayed good antiviral activities. 3D-QSAR models revealed that the appropriate compact electron-withdrawing and hydrophobic group at the benzene ring could enhance antiviral activity. These results could provide important structural insights for the design of highly active 1,4-pentadien-3-one derivatives. © 2015 Society of Chemical Industry.

Cocaine evokes a profile of oxidative stress and impacts innate antiviral response pathways in astrocytes.

PubMed

Cisneros, Irma E; Erdenizmenli, Mert; Cunningham, Kathryn A; Paessler, Slobodan; Dineley, Kelly T

2018-06-01

HIV-1 and Zika virus (ZIKV) represent RNA viruses with neurotropic characteristics. Infected individuals suffer neurocognitive disorders aggravated by environmental toxins, including drugs of abuse such as cocaine, exacerbating HIV-associated neurocognitive disorders through a combination of astrogliosis, oxidative stress and innate immune signaling; however, little is known about how cocaine impacts the progression of ZIKV neural perturbations. Impaired innate immune signaling is characterized by weakened antiviral activation of interferon signaling and alterations in inflammatory signaling, factors contributing to cognitive sequela associated with cocaine in HIV-1/ZIKV infection. We employed cellular/molecular biology techniques to test if cocaine suppresses the efficacy of astrocytes to initiate a Type 1 interferon response to HIV-1/ZIKV, in vitro. We found cocaine activated antiviral signaling pathways and type I interferon in the absence of inflammation. Cocaine pre-exposure suppressed antiviral responses to HIV-1/ZIKV, triggering antiviral signaling and phosphorylation of interferon regulatory transcription factor 3 to stimulate type I interferon gene transcription. Our data indicate that oxidative stress is a major driver of cocaine-mediated astrocyte antiviral immune responses. Although astrocyte antiviral signaling is activated following detection of foreign pathogenic material, oxidative stress and increased cytosolic double-stranded DNA (dsDNA) can drive antiviral signaling via stimulation of pattern recognition receptors. Pretreatment with the glial modulators propentofylline (PPF) or pioglitazone (PIO) reversed cocaine-mediated attenuation of astrocyte responses to HIV-1/ZIKV. Both PPF/PIO protected against cocaine-mediated generation of reactive oxygen species (ROS), increased dsDNA, antiviral signaling pathways and increased type I interferon, indicating that cocaine induces astrocyte type I interferon signaling in the absence of virus and oxidative stress is a major driver of cocaine-mediated astrocyte antiviral immunity. Lastly, PPF and PIO have therapeutic potential to ameliorate cocaine-mediated dysregulation of astrocyte antiviral immunity possibly via a myriad of protective actions including decreases in reactive phenotype and damaging immune factors. Published by Elsevier Ltd.

Evaluation of antiviral activities of Houttuynia cordata Thunb. extract, quercetin, quercetrin and cinanserin on murine coronavirus and dengue virus infection.

PubMed

Chiow, K H; Phoon, M C; Putti, Thomas; Tan, Benny K H; Chow, Vincent T

2016-01-01

To evaluate the in vitro activities of the ethyl acetate (EA) fraction of Houttuynia cordata (H. cordata) Thunb. (Saururaceae) and three of its constituent flavonoids (quercetin, quercitrin and rutin) against murine coronavirus and dengue virus (DENV). The antiviral activities of various concentrations of the EA fraction of H. cordata and flavonoids were assessed using virus neutralization tests against mouse hepatitis virus (MHV) and DENV type 2 (DENV-2). Cinanserin hydrochloride was also tested against MHV. The EA fraction of H. cordata was tested for acute oral toxicity in C57BL/6 mice. The EA fraction of H. cordata inhibited viral infectivity up to 6 d. Cinanserin hydrochloride was able to inhibit MHV for only 2 d. The 50% inhibitory concentrations (IC50) of the EA fraction of H. cordata added before the viral adsorption stage were 0.98 μg/mL for MHV and 7.50 μg/mL for DENV-2 with absence of cytotoxicity. The mice fed with the EA fraction up to 2000 mg/kg did not induce any signs of acute toxicity, with normal histological features of major organs. Certain flavonoids exhibited comparatively weaker antiviral activity, notably quercetin which could inhibit both MHV and DENV-2. This was followed by quercitrin which could inhibit DENV-2 but not MHV, whereas rutin did not exert any inhibitory effect on either virus. When quercetin was combined with quercitrin, enhancement of anti-DENV-2 activity and reduced cytotoxicity were observed. However, the synergistic efficacy of the flavonoid combination was still less than that of the EA fraction. The compounds in H. cordata contribute to the superior antiviral efficacy of the EA fraction which lacked cytotoxicity in vitro and acute toxicity in vivo. H. cordata has much potential for the development of antiviral agents against coronavirus and dengue infections. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

Favipiravir can evoke lethal mutagenesis and extinction of foot-and-mouth disease virus.

PubMed

de Avila, Ana Isabel; Moreno, Elena; Perales, Celia; Domingo, Esteban

2017-04-02

Antiviral agents are increasingly considered an option for veterinary medicine. An understanding of their mechanism of activity is important to plan their administration either as monotherapy or in combination with other agents. Previous studies have shown that the broad spectrum antiviral agent favipiravir (T-705) and its derivatives T-1105 and T-1106 are efficient inhibitors of foot-and-mouth disease virus (FMDV) replication in cell culture and in vivo. However, no mechanism for their activity against FMDV has been proposed. In the present study we show that favipiravir (T-705) can act as a lethal mutagen for FMDV in cell culture. Evidence includes virus extinction associated with increase in mutation frequency in the mutant spectrum of 860 residues of the 3D (polymerase)-coding region, and a decrease of specific infectivity while the consensus nucleotide sequence of the region analyzed remained invariant. The mutational spectrum evoked by favipiravir differs from that observed with other viruses in that no predominant transition type is observed, indicating that a movement towards A,U- or G,C-rich regions of sequence space is not a prerequisite for virus extinction. We discuss prospects for the use of favipiravir to assist in the control of FMDV, and its possible broader use in veterinary medicine as an extension of its current status as antiviral agent for human influenza virus. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative study to evaluate the anti-viral efficacy of Glycyrrhiza glabra extract and ribavirin against the Newcastle disease virus

PubMed Central

Omer, Muhammad Ovais; AlMalki, Waleed Hassan; Shahid, Imran; Khuram, Shahzada; Altaf, Imran; Imran, Saeed

2014-01-01

Background: The Newcastle disease represents as one of the most infectious viral disease, which afflicts almost every species of the birds. The causative agent of the disease is a single-stranded RNA virus with rapid replication capability. Objective: This study was performed to evaluate the comparative anti-viral efficacy and toxicity of Glycyrrhiza glabra aqueous extract and ribavirin against the Newcastle disease virus. Materials and Methods: The embryonated eggs were divided into six groups (A, B, C, D, E and F). Groups A, B, C, and D were further subdivided into three subgroups. The virus was identified by hemagglutination inhibition test. Spot hemagglutination test and viability of embryos were also evaluated. Three different concentrations i-e., 30 mg/100 ml, 60 mg/100 ml, and 120 mg/100 ml of the Glycyrrhiza aqueous extract and 10 μg/ml, 20 μg/ml, and 40 μg/ml ribavirin in deionized water were evaluated for their toxicity and anti-viral activity in the embryonated eggs. Results: 60 mg/100 ml concentration of Glycyrrhiza extract did not produce any toxicity in the embryonated eggs and showed anti-viral activity against the virus. Similarly, 20 μg/ml ribavirin was non-toxic in the embryonated eggs and contained anti-viral activity. Conclusion: It may conclude from the presented study that 60 mg/100 ml Glycyrrhiza extract inhibits replication of Newcastle disease virus and is non-toxic in the embryonated eggs. So, Glycyrrhiza glabra extract may be further evaluated in future to determine the potentially active compounds for their anti-viral activity against Newcastle disease virus. Furthermore, the mechanism of action of these active phytochemicals as an antiviral agent would be helpful to elucidate the pathogenesis of the disease. PMID:24497736

Phytochemistry, cytotoxicity and antiviral activity of Eleusine indica (sambau)

NASA Astrophysics Data System (ADS)

Iberahim, Rashidah; Yaacob, Wan Ahmad; Ibrahim, Nazlina

2015-09-01

Goose grass also known as Eleusine indica (EI) is a local medicinal plant that displays antioxidant, antimicrobial and anticancer activities. The present study is to determine the phytochemical constituents, cytotoxicity and antiviral activities for both crude extract and fraction obtained from the plant. The crude extract contained more secondary metabolites compared to the hexane fraction as gauged using standard phytochemical tests. Cytotoxicity screening against Vero cells using MTT assay showed that the CC50 values for crude extract and hexane fraction were 2.07 and 5.62 mg/ml respectively. The antiviral activity towards Herpes Simplex Virus type 1 (HSV-1) was determined using plaque reduction assay. The selective indices (SI = CC50 / EC50) for both methanol extract and hexane fraction were 12.2 and 6.2 respectively. These results demonstrate that the extract prepared from E. indica possesses phytochemical compound that was non cytotoxic to the cell with potential antiviral activity.

Antiviral effects of Curcuma longa L. against dengue virus in vitro and in vivo

NASA Astrophysics Data System (ADS)

Ichsyani, M.; Ridhanya, A.; Risanti, M.; Desti, H.; Ceria, R.; Putri, D. H.; Sudiro, T. M.; Dewi, B. E.

2017-12-01

Dengue is the most common infective disease caused by dengue virus (DENV) and endemic diseases in tropical and subtropical areas. Until now, there is no specific antiviral for dengue infection. It is known that viral load is related to disease severity. Curcuma longa L. (turmeric) with curcumin as major active compound has been identified for its antiviral effect. This study to determine antiviral effect of C. longa extract on DENV-2 in vitro and in vivo along with its toxicity in liver and kidney of ddY mice. Antiviral activity (IC50) and toxicity (CC50) in vitro was examined on Huh7it-1 cells by focus assay and a MTT assay, respectively. To determine the selectivity index (SI), we used CC50 and IC50 value. The safe doses obtained were used for toxicity tests of liver and kidney with histopathological and biochemical observations. The C. longa extracts was given orally with dose of 0.147 mg/mL for each mice at 2 hours after injected with DENV-2 infected Huh7it-1 cells. Serum was collected from intraorbital at 6 hours and 24 hours after infection and focus assay was used to determine viral load. In this study, the acquired value of IC50 was 17,91 μg/mL whereas the value of CC50 was 85,4 μg/mL. The value of SI of C. longa was 4.8. In vivo, we found that C. longa remarkable reduced of viral load after 24 hour. Histopathological examination showed no specific abnormalities in liver and kidney. There was no significant increase in levels of SGPT, SGOT, urea, and creatinine. From this study it can be concluded that C. longa could potentially be used as antiviral against DENV with low cytotoxicity and effective inhibition.

Novel Approaches for Targeting Antiviral Agents in the Treatment of Arena-, Bunya-, Flavi-, and Retroviral Infections

DTIC Science & Technology

1989-05-22

potentially useful antivirals (e... S-HMPA, selenazole, WIN 5177, arildone, phosphonoformic acid ) are currently under investigation. There are, however...by increasing dosage, this often results in toxicity. For example, a number of antiviral agents (ribavirin, adenine arabinoside, phosphonoformic acid ...Three possibilities exist for the activation of carrier bound drugs: 1) endocytosis and release in acidic endosomes; 2) extracellular activation at cell

Antiviral Screening of Multiple Compounds against Ebola Virus.

PubMed

Dowall, Stuart D; Bewley, Kevin; Watson, Robert J; Vasan, Seshadri S; Ghosh, Chandradhish; Konai, Mohini M; Gausdal, Gro; Lorens, James B; Long, Jason; Barclay, Wendy; Garcia-Dorival, Isabel; Hiscox, Julian; Bosworth, Andrew; Taylor, Irene; Easterbrook, Linda; Pitman, James; Summers, Sian; Chan-Pensley, Jenny; Funnell, Simon; Vipond, Julia; Charlton, Sue; Haldar, Jayanta; Hewson, Roger; Carroll, Miles W

2016-10-27

In light of the recent outbreak of Ebola virus (EBOV) disease in West Africa, there have been renewed efforts to search for effective antiviral countermeasures. A range of compounds currently available with broad antimicrobial activity have been tested for activity against EBOV. Using live EBOV, eighteen candidate compounds were screened for antiviral activity in vitro. The compounds were selected on a rational basis because their mechanisms of action suggested that they had the potential to disrupt EBOV entry, replication or exit from cells or because they had displayed some antiviral activity against EBOV in previous tests. Nine compounds caused no reduction in viral replication despite cells remaining healthy, so they were excluded from further analysis (zidovudine; didanosine; stavudine; abacavir sulphate; entecavir; JB1a; Aimspro; celgosivir; and castanospermine). A second screen of the remaining compounds and the feasibility of appropriateness for in vivo testing removed six further compounds (ouabain; omeprazole; esomeprazole; Gleevec; D-LANA-14; and Tasigna). The three most promising compounds (17-DMAG; BGB324; and NCK-8) were further screened for in vivo activity in the guinea pig model of EBOV disease. Two of the compounds, BGB324 and NCK-8, showed some effect against lethal infection in vivo at the concentrations tested, which warrants further investigation. Further, these data add to the body of knowledge on the antiviral activities of multiple compounds against EBOV and indicate that the scientific community should invest more effort into the development of novel and specific antiviral compounds to treat Ebola virus disease.

Chemically engineered sulfated glucans from rice bran exert strong antiviral activity at the stage of viral entry.

PubMed

Ray, Bimalendu; Hutterer, Corina; Bandyopadhyay, Shruti S; Ghosh, Kanika; Chatterjee, Udipta R; Ray, Sayani; Zeitträger, Isabel; Wagner, Sabrina; Marschall, Manfred

2013-12-27

Attachment and entry of many viruses are mediated by their affinity for polysaccharides present on the surface of target cells. In this paper, we demonstrate that sulfated glucans isolated from rice (Oryza sativa) can be utilized as experimental drugs exerting strong antiviral activity. In particular, oleum-DMF-based extraction is described as a procedure for the generation of chemically engineered glucans from commercially available rice bran. The one-step procedure has the potential to provide a spectrum of related glucans with varying molecular masses and modifications, including sulfation. The sulfated glucans P444, P445, and P446 possess increased antiviral activity compared to a previously described glucan (S1G). P444, P445, and P446 were highly active against human cytomegalovirus (HCMV), moderately active against other members of the family Herpesviridae, while not active against unrelated viruses. Specific experimentation with HCMV-infected cells provided evidence that antiviral activity was based on inhibition of viral entry and that inhibition occurred in the absence of drug-induced cytotoxicity. These findings underline the high potential of sulfated glucans for antiviral research and drug development. In addition, the procedure described for the efficient transformation of glucan hydroxy groups to sulfate groups may be similarly beneficial for the chemical alteration of other natural products.

Antiviral Activity of Bay 41-4109 on Hepatitis B Virus in Humanized Alb-uPA/SCID Mice

PubMed Central

Brezillon, Nicolas; Brunelle, Marie-Noëlle; Massinet, Hélène; Giang, Eric; Lamant, Céline; DaSilva, Lucie; Berissi, Sophie; Belghiti, Jacques; Hannoun, Laurent; Puerstinger, Gherard; Wimmer, Eva; Neyts, Johan; Hantz, Olivier; Soussan, Patrick; Morosan, Serban; Kremsdorf, Dina

2011-01-01

Current treatments for HBV chronic carriers using interferon alpha or nucleoside analogues are not effective in all patients and may induce the emergence of HBV resistant strains. Bay 41-4109, a member of the heteroaryldihydropyrimidine family, inhibits HBV replication by destabilizing capsid assembly. The aim of this study was to determine the antiviral effect of Bay 41-4109 in a mouse model with humanized liver and the spread of active HBV. Antiviral assays of Bay 41-4109 on HepG2.2.15 cells constitutively expressing HBV, displayed an IC50 of about 202 nM with no cell toxicity. Alb-uPA/SCID mice were transplanted with human hepatocytes and infected with HBV. Ten days post-infection, the mice were treated with Bay 41-4109 for five days. During the 30 days of follow-up, the HBV load was evaluated by quantitative PCR. At the end of treatment, decreased HBV viremia of about 1 log(10) copies/ml was observed. By contrast, increased HBV viremia of about 0.5 log(10) copies/ml was measured in the control group. Five days after the end of treatment, a rebound of HBV viremia occurred in the treated group. Furthermore, 15 days after treatment discontinuation, a similar expression of the viral capsid was evidenced in liver biopsies. Our findings demonstrate that Bay 41-4109 displayed antiviral properties against HBV in humanized Alb-uPA/SCID mice and confirm the usefulness of Alb-uPA/SCID mice for the evaluation of pharmaceutical compounds. The administration of Bay 41-4109 may constitute a new strategy for the treatment of patients in escape from standard antiviral therapy. PMID:22162746

Antiviral activity of maca (Lepidium meyenii) against human influenza virus.

PubMed

Del Valle Mendoza, Juana; Pumarola, Tomàs; Gonzales, Libertad Alzamora; Del Valle, Luis J

2014-09-01

To investigate antiviral activity of maca to reduce viral load in Madin-Darby canine kidney (MDCK) cells infected with influenza type A and B viruses (Flu-A and Flu-B, respectively). Maca were extracted with methanol (1:2, v/v). The cell viability and toxicity of the extracts were evaluated on MDCK cells using method MTT assay. Antiviral activity of compounds against Flu-A and Flu-B viruses was assayed using a test for determining the inhibition of the cytopathic effect on cell culture and multiplex RT-PCR. The methanol extract of maca showed low cytotoxicity and inhibited influenza-induced cytopathic effect significantly, while viral load was reduced via inhibition of viral growth in MDCK infected cells. Maca contains potent inhibitors of Flu-A and Flu-B with a selectivity index [cytotoxic concentration 50%/IC50] of 157.4 and 110.5, respectively. In vitro assays demonstrated that maca has antiviral activity not only against Flu-A (like most antiviral agents) but also Flu-B viruses, providing remarkable therapeutic benefits. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Variability of interferon-λ induction and antiviral activity in Nipah virus infected differentiated human bronchial epithelial cells of two human donors.

PubMed

Sauerhering, Lucie; Müller, Helena; Behner, Laura; Elvert, Mareike; Fehling, Sarah Katharina; Strecker, Thomas; Maisner, Andrea

2017-10-01

Highly pathogenic Nipah virus (NiV) generally causes severe encephalitis in humans. Respiratory symptoms are infrequently observed, likely reflecting variations in infection kinetics in human airways. Supporting this idea, we recently identified individual differences in NiV replication kinetics in cultured airway epithelia from different human donors. As type III interferons (IFN-λ) represent major players in the defence mechanism against viral infection of the respiratory mucosa, we studied IFN-λ induction and antiviral activity in NiV-infected primary differentiated human bronchial epithelial cells (HBEpCs) cultured under air-liquid interface conditions. Our studies revealed that IFN-λ was upregulated in airway epithelia upon NiV infection. We also show that IFN-λ pretreatment efficiently inhibited NiV replication. Interestingly, the antiviral activity of IFN-λ varied in HBEpCs from two different donors. Increased sensitivity to IFN-λ was associated with higher expression levels of IFN-λ receptors, enhanced phosphorylation of STAT1, as well as enhanced induction of interferon-stimulated gene expression. These findings suggest that individual variations in IFN-λ receptor expression affecting IFN responsiveness can play a functional role for NiV replication kinetics in human respiratory epithelial cells of different donors.

Selective Targeting of Antiviral and Immunomodulating Agents in the Treatment of Arenavirus Infections

DTIC Science & Technology

1987-10-01

observed with free MTP-PE. In addition to our observations on peritoneal and alveolar macrophages, we also examined the effect of MTP-PE treatment on liver...Ir OIC FILE COPY C2 ILn 00 NM AD _____ N SELECTIVE TARGETING OF ANTIVIRAL AND IMMUNOMODULATING AGENTS IN THE TREATMENT OF ARENAVIRUS INFECTIONS "Kc...Selective Targeting of Antiviral and Immunomodulating Agents in the Treatment of Arenavirus Injections 12. PERSONAL AUTHOR(S) J. David Gangemi 13a. TYPE OF

Antiviral activity, safety, and pharmacokinetics/pharmacodynamics of dolutegravir as 10-day monotherapy in HIV-1-infected adults.

PubMed

Min, Sherene; Sloan, Louis; DeJesus, Edwin; Hawkins, Trevor; McCurdy, Lewis; Song, Ivy; Stroder, Richard; Chen, Shuguang; Underwood, Mark; Fujiwara, Tamio; Piscitelli, Stephen; Lalezari, Jay

2011-09-10

To evaluate the antiviral activity, safety, pharmacokinetics, and pharmacokinetics/pharmacodynamics of dolutegravir (DTG), a next-generation HIV integrase inhibitor (INI), as short-term monotherapy. A phase IIa, randomized, double-blind, dose-ranging study. In this study, INI-naive, HIV-1-infected adults currently off antiretroviral therapy were randomized to receive DTG (2, 10, or 50 mg) or placebo once daily for 10 days in an eight active and two placebo randomization scheme per DTG dose. Placebo patients were pooled for the purpose of analysis. Thirty-five patients (n = 9 for DTG 2 and 10 mg, n = 10 for DTG 50 mg, and n = 7 for placebo) were enrolled. Baseline characteristics were similar across dose groups. Significant reductions in plasma HIV-1 RNA from baseline to day 11 were observed for all DTG dose groups compared with placebo (P < 0.001), with a mean decrease of 1.51-2.46 log(10) copies/ml. In addition, a well characterized dose-response relationship was observed for viral load decrease. Most patients (seven of 10, 70%) receiving DTG 50 mg achieved plasma HIV-1 RNA less than 50 copies/ml. The pharmacokinetic variability was low (coefficient of variation, range 25-50%). Plasma HIV-1 RNA reduction was best predicted by Cτ using an E(max) model. The most common adverse events were diarrhea, fatigue, and headache; the majority of adverse events were mild or moderate in severity. Dolutegravir demonstrated potent antiviral activity, good short-term tolerability, low pharmacokinetic variability, and a predictable pharmacokinetics/pharmacodynamics relationship, which support once-daily dosing without a pharmacokinetic booster in integrase-naive patients in future studies.

Cytotoxicity and antiviral activity of methanol extract from Polygonum minus

NASA Astrophysics Data System (ADS)

Wahab, Noor Zarina Abd; Bunawan, Hamidun; Ibrahim, Nazlina

2015-09-01

A study was carried out to test the cytotoxicity and antiviral effects of methanolic extracts from the leaves and stem of Polygonum minus or kesum. Cytotoxicity tests were performed on Vero cells indicates the LC50 value for leaf extract towards the Vero cells was 875 mg/L and the LC50 value for stem extract was 95 mg/L. The LC50 values indidcate the non-cytotoxic effect of the extracts and worth for further testing. Antiviral test were carried out towards herpes simplex virus infected Vero cells using three concentration of extract which were equivalent to 1.0 LC50, 0.1 LC50 and 0.01 LC50. Three different treatments to detect antiviral activity were used. Mild antiviral activity of the stem extract was detected when cells were treated for 24 hours with plant extract before viral infection. This demonstrates the capability of the test compound to protect the cells from viral attachment and of the possible prophylactic effect of the P. minus stem methanol extract.

Intranasal administration of poly-gamma glutamate induced antiviral activity and protective immune responses against H1N1 influenza A virus infection.

PubMed

Kim, Eun-Ha; Choi, Young-Ki; Kim, Chul-Joong; Sung, Moon-Hee; Poo, Haryoung

2015-10-06

The global outbreak of a novel swine-origin strain of the 2009 H1N1 influenza A virus and the sudden, worldwide increase in oseltamivir-resistant H1N1 influenza A viruses highlight the urgent need for novel antiviral therapy. Here, we investigated the antiviral efficacy of poly-gamma glutamate (γ-PGA), a safe and edible biomaterial that is naturally synthesized by Bacillus subtilis, against A/Puerto Rico/8/1934 (PR8) and A/California/04/2009 (CA04) H1N1 influenza A virus infections in C57BL/6 mice. Intranasal administration of γ-PGA for 5 days post-infection improved survival, increased production of antiviral cytokines including interferon-beta (IFN-β) and interleukin-12 (IL-12), and enhanced activation of natural killer (NK) cells and influenza antigen-specific cytotoxic T lymphocytes (CTL) activity. These results suggest that γ-PGA protects mice against H1N1 influenza A virus by enhancing antiviral immune responses.

3,7-Dideazaneplanocin: Synthesis and antiviral analysis.

PubMed

Yin, Xue-Qiang; Schneller, Stewart W

2017-12-01

Objective To synthesize 3,7-dideazaneplanocin and evaluate its antiviral potential. Methods The target 3,7-dideazaneplanocin has been prepared in five steps from a readily available cyclopentenol. A thorough in vitro antiviral analysis was conducted versus both DNA and RNA viruses. Results A rational synthesis of 3,7-dideazaneplanocin was conceived and successfully pursued in such a way that it can be adapted to various analogs of 3,7-dideazaneplanocin. Using standard antiviral assays, no activity for 3,7-dideazaneplanocn was found. Conclusion Two structural features are necessary for adenine-based carbocyclic nucleosides (like neplanocin) for potential antiviral properties: (i) inhibition of S-adenosylhomocysteine hydrolase and/or (ii) C-5' activation via the mono-nucleotide. These two requisite adenine structural features to fit these criteria are not present in in the target 3,7-dideazaneplanocin: (i) an N-7 is necessary for inhibition of the hydrolase and the N-3 is claimed to be essential for phosphorylation at C-5'. Thus, it is not surprising that 3,7-dideazaneplaoncin lacked antiviral properties.

Antiviral evaluation of plants from Brazilian Atlantic Tropical Forest.

PubMed

Andrighetti-Fröhner, C R; Sincero, T C M; da Silva, A C; Savi, L A; Gaido, C M; Bettega, J M R; Mancini, M; de Almeida, M T R; Barbosa, R A; Farias, M R; Barardi, C R M; Simões, C M O

2005-06-01

The antiviral activity of six medicinal plants from Brazilian Atlantic Tropical Forest was investigated against two viruses: herpes simplex virus type 1 (HSV-1) and poliovirus type 2 (PV-2). Cuphea carthagenensis and Tillandsia usneoides extracts showed the best antiherpes activity. T. usneoides dichloromethane, ethyl acetate and n-butanol extracts, and Lippia alba n-butanol extract showed inhibition of HSV-1, strain 29R/acyclovir resistant. In addition, only L. alba ethyl acetate extract showed antipoliovirus activity. These results corroborate that medicinal plants can be a rich source of potential antiviral compounds.

Comparative study on in vitro activities of citral, limonene and essential oils from Lippia citriodora and L. alba on yellow fever virus.

PubMed

Gómez, Luz Angela; Stashenko, Elena; Ocazionez, Raquel Elvira

2013-02-01

The aim of this study was to compare the antiviral activities in vitro of citral, limonene and essential oils (EOs) from Lippia citriodora and L. alba on the replication of yellow fever virus (YFV). Citral and EOs were active before and after virus adsorption on cells; IC50 values were between 4.3 and 25 microg/mL and SI ranged from 1.1 to 10.8. Results indicate that citral could contribute to the antiviral activity of the L. citriodora EO. Limonene was not active and seemed to play an insignificant role in the antiviral activity of the examined EOs.

Discovery of host-targeted covalent inhibitors of dengue virus

PubMed Central

de Wispelaere, Mélissanne; Carocci, Margot; Liang, Yanke; Liu, Qingsong; Sun, Eileen; Vetter, Michael L.; Wang, Jinhua; Gray, Nathanael S.; Yang, Priscilla L.

2017-01-01

We report here on an approach targeting the host reactive cysteinome to identify inhibitors of host factors required for the infectious cycle of Flaviviruses and other viruses. We used two parallel cellular phenotypic screens to identify a series of covalent inhibitors, exemplified by QL-XII-47, that are active against dengue virus. We show that the compounds effectively block viral protein expression and that this inhibition is associated with repression of downstream processes of the infectious cycle, and thus significantly contributes to the potent antiviral activity of these compounds. We demonstrate that QL-XII-47’s antiviral activity requires selective, covalent modification of a host target by showing that the compound's antiviral activity is recapitulated when cells are preincubated with QL-XII-47 and then washed prior to viral infection and by showing that QL-XII-47R, a non-reactive analog, lacks antiviral activity at concentrations more than 20-fold higher than QL-XII-47's IC90. QL-XII-47’s inhibition of Zika virus, West Nile virus, hepatitis C virus, and poliovirus further suggests that it acts via a target mediating inhibition of these other medically relevant viruses. These results demonstrate the utility of screens targeting the host reactive cysteinome for rapid identification of compounds with potent antiviral activity. PMID:28034743

Influenza A Virus Dysregulates Host Histone Deacetylase 1 That Inhibits Viral Infection in Lung Epithelial Cells

PubMed Central

Nagesh, Prashanth Thevkar

2016-01-01

ABSTRACT Viruses dysregulate the host factors that inhibit virus infection. Here, we demonstrate that human enzyme, histone deacetylase 1 (HDAC1) is a new class of host factor that inhibits influenza A virus (IAV) infection, and IAV dysregulates HDAC1 to efficiently replicate in epithelial cells. A time-dependent decrease in HDAC1 polypeptide level was observed in IAV-infected cells, reducing to <50% by 24 h of infection. A further depletion (97%) of HDAC1 expression by RNA interference increased the IAV growth kinetics, increasing it by >3-fold by 24 h and by >6-fold by 48 h of infection. Conversely, overexpression of HDAC1 decreased the IAV infection by >2-fold. Likewise, a time-dependent decrease in HDAC1 activity, albeit with slightly different kinetics to HDAC1 polypeptide reduction, was observed in infected cells. Nevertheless, a further inhibition of deacetylase activity increased IAV infection in a dose-dependent manner. HDAC1 is an important host deacetylase and, in addition to its role as a transcription repressor, HDAC1 has been lately described as a coactivator of type I interferon response. Consistent with this property, we found that inhibition of deacetylase activity either decreased or abolished the phosphorylation of signal transducer and activator of transcription I (STAT1) and expression of interferon-stimulated genes, IFITM3, ISG15, and viperin in IAV-infected cells. Furthermore, the knockdown of HDAC1 expression in infected cells decreased viperin expression by 58% and, conversely, the overexpression of HDAC1 increased it by 55%, indicating that HDAC1 is a component of IAV-induced host type I interferon antiviral response. IMPORTANCE Influenza A virus (IAV) continues to significantly impact global public health by causing regular seasonal epidemics, occasional pandemics, and zoonotic outbreaks. IAV is among the successful human viral pathogens that has evolved various strategies to evade host defenses, prevent the development of a universal vaccine, and acquire antiviral drug resistance. A comprehensive knowledge of IAV-host interactions is needed to develop a novel and alternative anti-IAV strategy. Host produces a variety of factors that are able to fight IAV infection by employing various mechanisms. However, the full repertoire of anti-IAV host factors and their antiviral mechanisms has yet to be identified. We have identified here a new host factor, histone deacetylase 1 (HDAC1) that inhibits IAV infection. We demonstrate that HDAC1 is a component of host innate antiviral response against IAV, and IAV undermines HDAC1 to limit its role in antiviral response. PMID:26912629

Comparison of the antiviral potential among soluble forms of herpes simplex virus type-2 glycoprotein D receptors, herpes virus entry mediator A, nectin-1 and nectin-2, in transgenic mice.

PubMed

Fujimoto, Yoshikazu; Tomioka, Yukiko; Ozaki, Kinuyo; Takeda, Keiko; Suyama, Haruka; Yamamoto, Sayo; Takakuwa, Hiroki; Morimatsu, Masami; Uede, Toshimitsu; Ono, Etsuro

2017-07-01

Herpesvirus entry mediator A (HVEM), nectin-1 and nectin-2 are cellular receptors of glycoprotein D (gD) of herpes simplex virus type-2 (HSV-2). It has been shown that soluble forms of HSV gD receptors have the antiviral potential in cultured cells and transgenic mice. Here, to compare antiviral potential of soluble forms of HVEM, nectin-1 and nectin-2 against HSV-2 infections in vivo, transgenic mice expressing fusion proteins consisting of the entire ectodomain of HVEM, nectin-1 or nectin-2 and the Fc portion of human IgG (HVEMIg, nectin-1Ig and nectin-2Ig, respectively) were intraperitoneally infected with HSV-2. In the infection with 3 MLD50 (50 % mouse lethal dose), effective resistance was not observed in transgenic mice expressing nectin-2Ig. In a transgenic mouse line with high expression of nectin-1Ig, significant protection from the infection with 30 and 300 MLD50 was observed (survival rate of 100 and 71 %, respectively). On the other hand, transgenic mice expressing HVEMIg showed a complete resistance to the lethal infection even with 300 MLD50 (survival rate of 100 %). These results demonstrated that HVEMIg could exert effective antiviral activities against HSV-2 infections in vivo as compared with other soluble forms of HSV gD receptors.

Cross Talk between Nucleotide Synthesis Pathways with Cellular Immunity in Constraining Hepatitis E Virus Replication

PubMed Central

Wang, Yijin; Wang, Wenshi; Xu, Lei; Zhou, Xinying; Shokrollahi, Ehsan; Felczak, Krzysztof; van der Laan, Luc J. W.; Pankiewicz, Krzysztof W.; Sprengers, Dave; Raat, Nicolaas J. H.; Metselaar, Herold J.; Peppelenbosch, Maikel P.

2016-01-01

Viruses are solely dependent on host cells to propagate; therefore, understanding virus-host interaction is important for antiviral drug development. Since de novo nucleotide biosynthesis is essentially required for both host cell metabolism and viral replication, specific catalytic enzymes of these pathways have been explored as potential antiviral targets. In this study, we investigated the role of different enzymatic cascades of nucleotide biosynthesis in hepatitis E virus (HEV) replication. By profiling various pharmacological inhibitors of nucleotide biosynthesis, we found that targeting the early steps of the purine biosynthesis pathway led to the enhancement of HEV replication, whereas targeting the later step resulted in potent antiviral activity via the depletion of purine nucleotide. Furthermore, the inhibition of the pyrimidine pathway resulted in potent anti-HEV activity. Interestingly, all of these inhibitors with anti-HEV activity concurrently triggered the induction of antiviral interferon-stimulated genes (ISGs). Although ISGs are commonly induced by interferons via the JAK-STAT pathway, their induction by nucleotide synthesis inhibitors is completely independent of this classical mechanism. In conclusion, this study revealed an unconventional novel mechanism of cross talk between nucleotide biosynthesis pathways and cellular antiviral immunity in constraining HEV infection. Targeting particular enzymes in nucleotide biosynthesis represents a viable option for antiviral drug development against HEV. HEV is the most common cause of acute viral hepatitis worldwide and is also associated with chronic hepatitis, especially in immunocompromised patients. Although often an acute and self-limiting infection in the general population, HEV can cause severe morbidity and mortality in certain patients, a problem compounded by the lack of FDA-approved anti-HEV medication available. In this study, we have investigated the role of the nucleotide synthesis pathway in HEV infection and its potential for antiviral drug development. We show that targeting the later but not the early steps of the purine synthesis pathway exerts strong anti-HEV activity. In particular, IMP dehydrogenase (IMPDH) is the most important anti-HEV target of this cascade. Importantly, the clinically used IMPDH inhibitors, including mycophenolic acid and ribavirin, have potent anti-HEV activity. Furthermore, targeting the pyrimidine synthesis pathway also exerts potent antiviral activity against HEV. Interestingly, antiviral effects of nucleotide synthesis pathway inhibitors appear to depend on the medication-induced transcription of antiviral interferon-stimulated genes. Thus, this study reveals an unconventional novel mechanism as to how nucleotide synthesis pathway inhibitors can counteract HEV replication. PMID:26926637

In vitro antiviral activity of aqueous extract of Phaleria macrocarpa fruit against herpes simplex virus type 1

NASA Astrophysics Data System (ADS)

Ismaeel, Mahmud Yusef Yusef; Dyari, Herryawan Ryadi Eziwar; Yaacob, Wan Ahmad; Ibrahim, Nazlina

2018-04-01

Phaleria macrocarpa fruits have been used as herbal medicine for several diseases. This study aims to determine the cytotoxicity and antiviral activity of aqueous extract of P. macrocarpa fruit (AEPMF). Phytochemical analysis showed the presence of steroids, tannins, flavones aglycones, saponins, terpenoids and alkaloids. AEPMF was found to contain protein with the concentration of 740 µg/mL. The cytotoxicity towards Vero cell was evaluated using MTT assay with 50% cytotoxic concentration (CC50) value of AEPMF 5 mg/mL. The finding indicates that AEPMF is safe and not toxic towards Vero cells. Screening by plaque reduction assay showed that AEPMF have antiviral activity against herpes simplex virus type 1 (HSV-1) with effective concentration (EC50) was 0.28 mg/mL. The selective index (SI=CC50/EC50) of AEPMF is 17.9 indicating AEPMF have potential for further evaluation in antiviral activity.

Discovery of dapivirine, a nonnucleoside HIV-1 reverse transcriptase inhibitor, as a broad-spectrum antiviral against both influenza A and B viruses.

PubMed

Hu, Yanmei; Zhang, Jiantao; Musharrafieh, Rami Ghassan; Ma, Chunlong; Hau, Raymond; Wang, Jun

2017-09-01

The emergence of multidrug-resistant influenza viruses poses a persistent threat to public health. The current prophylaxis and therapeutic interventions for influenza virus infection have limited efficacy due to the continuous antigenic drift and antigenic shift of influenza viruses. As part of our ongoing effort to develop the next generation of influenza antivirals with broad-spectrum antiviral activity and a high genetic barrier to drug resistance, in this study we report the discovery of dapivirine, an FDA-approved HIV nonnucleoside reverse transcriptase inhibitor, as a broad-spectrum antiviral against multiple strains of influenza A and B viruses with low micromolar efficacy. Mechanistic studies revealed that dapivirine inhibits the nuclear entry of viral ribonucleoproteins at the early stage of viral replication. As a result, viral RNA and protein synthesis were inhibited. Furthermore, dapivirine has a high in vitro genetic barrier to drug resistance, and its antiviral activity is synergistic with oseltamivir carboxylate. In summary, the in vitro antiviral results of dapivirine suggest it is a promising candidate for the development of the next generation of dual influenza and HIV antivirals. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical composition of 8 eucalyptus species' essential oils and the evaluation of their antibacterial, antifungal and antiviral activities

PubMed Central

2012-01-01

Background In 1957, Tunisia introduced 117 species of Eucalyptus; they have been used as fire wood, for the production of mine wood and to fight erosion. Actually, Eucalyptus essential oil is traditionally used to treat respiratory tract disorders such as pharyngitis, bronchitis, and sinusitis. A few investigations were reported on the biological activities of Eucalyptus oils worldwide. In Tunisia, our previous works conducted in 2010 and 2011 had been the first reports to study the antibacterial activities against reference strains. At that time it was not possible to evaluate their antimicrobial activities against clinical bacterial strains and other pathogens such as virus and fungi. Methods The essential oils of eight Eucalyptus species harvested from the Jbel Abderrahman, Korbous (North East Tunisia) and Souinet arboreta (North of Tunisia) were evaluated for their antimicrobial activities by disc diffusion and microbroth dilution methods against seven bacterial isolates: Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Streptococcus pyogenes. In addition, the bactericidal, fungicidal and the antiviral activities of the tested oils were carried out. Results Twenty five components were identified by GC/FID and GC/MS. These components were used to correlate with the biological activities of the tested oils. The chemical principal component analysis identified three groups, each of them constituted a chemotype. According to the values of zone diameter and percentage of the inhibition (zdi, % I, respectively), four groups and subgroups of bacterial strains and three groups of fungal strains were characterized by their sensitivity levels to Eucalyptus oils. The cytotoxic effect and the antiviral activity varied significantly within Eucalyptus species oils. Conclusions E. odorata showed the strongest activity against S. aureus, H. influenzae, S. agalactiae, S. pyogenes, S. pneumoniae and against all the tested fungal strains. In addition, E. odorata oil showed the most cytotoxic effect. However, the best antiviral activity appeared with E. bicostata. Virus pretreatment with E. bicostata essential oil showed better antiviral activity (IC50 = 0.7 mg/ml, SI = 22.8) than cell-pretreatment (IC50 = 4.8 mg/ml, SI = 3.33). The essential oil of E. astringens showed antiviral activity only when incubated with virus prior to cell infection. This activity was dose-dependent and the antiviral activity diminished with the decreasing essential oil concentration. PMID:22742534

Antiviral effect of diammonium glycyrrhizinate on cell infection by porcine parvovirus

USDA-ARS?s Scientific Manuscript database

Porcine parvovirus (PPV) can cause reproductive failure in swine resulting in economic losses to the industry. Antiviral effects of diammonium glycyrrhizinate (DG) have been reported on several animal viruses; however, to date it has yet to be tested on PPV. In this study, the antiviral activity of ...

Effect of compounds with antibacterial activities in human milk on respiratory syncytial virus and cytomegalovirus in vitro.

PubMed

Portelli, J; Gordon, A; May, J T

1998-11-01

The effect of some antibacterial compounds present in human milk were tested for antiviral activity against respiratory syncytial virus, Semliki Forest virus and cytomegalovirus. These included the gangliosides GM1, GM2 and GM3, sialyl-lactose, lactoferrin and chondroitin sulphate A, B and C, which were all tested for their ability to inhibit the viruses in cell culture. Of the compounds tested, only the ganglioside GM2, chondroitin sulphate B and lactoferrin inhibited the absorption and growth of respiratory syncytial virus in cell culture, and none inhibited the growth of Semliki Forest virus, indicating that lipid antiviral activity was not associated with any of the gangliosides. While the concentrations of these two compounds required to inhibit respiratory syncytial virus were in excess of those present in human milk, sialyl-lactose concentrations similar to those present in human milk increased the growth of cytomegalovirus. Lactoferrin was confirmed as inhibiting both respiratory syncytial virus and cytomegalovirus growth in culture even when used at lower concentrations than those present in human milk. The antiviral activities of GM2, chondroitin sulphate B and lactoferrin were tested when added to an infant formula. Lactoferrin continued to have antiviral activity against cytomegalovirus, but a lower activity against respiratory syncytial virus; ganglioside GM2 and chondroitin sulphate B still maintained antiviral activity against respiratory syncytial virus.

Novel α,β-unsaturated amide derivatives bearing α-amino phosphonate moiety as potential antiviral agents.

PubMed

Lan, Xianmin; Xie, Dandan; Yin, Limin; Wang, Zhenzhen; Chen, Jin; Zhang, Awei; Song, Baoan; Hu, Deyu

2017-09-15

Based on flexible construction and broad bioactivity of ferulic acid, a series of novel α,β-unsaturated amide derivatives bearing α-aminophosphonate moiety were designed, synthesized and systematically evaluated for their antiviral activity. Bioassay results indicated that some compounds exhibited good antiviral activities against cucumber mosaic virus (CMV) and tobacco mosaic virus (TMV) in vivo. Especially, compound g18 showed excellent curative and protective activities against CMV, with half-maximal effective concentration (EC 50 ) values of 284.67μg/mL and 216.30μg/mL, which were obviously superior to that of Ningnanmycin (352.08μg/mL and 262.53μg/mL). Preliminary structure-activity relationships (SARs) analysis revealed that the introduction of electron-withdrawing group at the 2-position or 4-position of the aromatic ring is favorable for antiviral activity. Present work provides a promising template for development of potential inhibitor of plant virus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antiviral activity of polysaccharide extract from Laminaria japonica against respiratory syncytial virus.

PubMed

Cao, Yin-Guang; Hao, Yu; Li, Zhi-Hui; Liu, Shun-Tao; Wang, Le-Xin

2016-12-01

This study was designed to investigate the inhibition activity of polysaccharide extract from Laminaria japonica against RSV. The polysaccharide from Laminaria japonica was isolated by ethanol precipitation. HEK293 cells were infected with RVS, and the antiviral activity of polysaccharide extract against RSV in host cells was tested. By using ELISA and western blot assay, the expression level of IFN-α and IRF3 and their functional roles in polysaccharide-mediated antiviral activity against RSV were investigated. The polysaccharide extract from Laminaria japonica had low toxicity to HEK293 cell. The TC50 to HEK293 cells was up to 1.76mg/mL. Furthermore, the EC50 of polysaccharide extract to RSV was 5.27μg/mL, and TI was 334. The polysaccharide extract improved IRF-3 expression which promoted the level of IFN-α. Polysaccharide extract from Laminaria japonica elicits antiviral activity against RSV by up-regulation of IRF3 signaling-mediated IFN-α production. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Use of Disposable Micro Tissue Culture Plates for Antiviral and Interferon Induction Studies

PubMed Central

Sidwell, Robert W.; Huffman, John H.

1971-01-01

A reproducible test system requiring small amounts of test compound was developed for evaluating antiviral and interferon-inducing activity. In the antiviral experiments, KB cells were grown in disposable polystyrene microplates covered with a standard domestic plastic wrap. Viruses used in the system were types 1 and 2 herpes simplex virus, vaccinia virus, type 3 adenovirus, myxoma virus, pseudorabies virus, type 3 parainfluenza virus, types 1A and 13 rhinovirus, vesicular stomatitis virus, coxsackievirus B, and type 2 poliovirus. Inhibition of viral cytopathogenic effect was the primary criterion of evaluation of antiviral activity. Reduction in cell and supernatant fluid virus titers was used as a secondary means of evaluation. The microplate system was adaptable for determining prophylactic, therapeutic, and inactivating effects against viruses. Mouse L-929 cells were used for the interferon induction studies, with vesicular stomatitis virus utilized as the indicator of interferon activity. Known active compounds evaluated in this microplate system had activity similar to that seen in macro in vitro systems. PMID:4332040

Chemical-controlled Activation of Antiviral Myxovirus Resistance Protein 1.

PubMed

Verhelst, Judith; Van Hoecke, Lien; Spitaels, Jan; De Vlieger, Dorien; Kolpe, Annasaheb; Saelens, Xavier

2017-02-10

The antiviral myxovirus resistance protein 1 (MX1) is an interferon-induced GTPase that plays an important role in the defense of mammalian cells against influenza A viruses. Mouse MX1 interacts with the influenza ribonucleoprotein complexes (vRNPs) and can prevent the interaction between polymerase basic 2 (PB2) and the nucleoprotein (NP) of influenza A viruses. However, it is unclear whether mouse MX1 disrupts the PB2-NP interaction in the context of pre-existing vRNPs or prevents the assembly of new vRNP components. Here, we describe a conditionally active mouse MX1 variant that only exerts antiviral activity in the presence of a small molecule drug. Once activated, this MX1 construct phenocopies the antiviral and NP binding activity of wild type MX1. The interaction between PB2 and NP is disrupted within minutes after the addition of the small molecule activator. These findings support a model in which mouse MX1 interacts with the incoming influenza A vRNPs and inhibits their activity by disrupting the PB2-NP interaction. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Chemical-controlled Activation of Antiviral Myxovirus Resistance Protein 1*

PubMed Central

Verhelst, Judith; Van Hoecke, Lien; Spitaels, Jan; De Vlieger, Dorien; Kolpe, Annasaheb

2017-01-01

The antiviral myxovirus resistance protein 1 (MX1) is an interferon-induced GTPase that plays an important role in the defense of mammalian cells against influenza A viruses. Mouse MX1 interacts with the influenza ribonucleoprotein complexes (vRNPs) and can prevent the interaction between polymerase basic 2 (PB2) and the nucleoprotein (NP) of influenza A viruses. However, it is unclear whether mouse MX1 disrupts the PB2-NP interaction in the context of pre-existing vRNPs or prevents the assembly of new vRNP components. Here, we describe a conditionally active mouse MX1 variant that only exerts antiviral activity in the presence of a small molecule drug. Once activated, this MX1 construct phenocopies the antiviral and NP binding activity of wild type MX1. The interaction between PB2 and NP is disrupted within minutes after the addition of the small molecule activator. These findings support a model in which mouse MX1 interacts with the incoming influenza A vRNPs and inhibits their activity by disrupting the PB2-NP interaction. PMID:28011636

Venom Components of Iranian Scorpion Hemiscorpius lepturus Inhibit the Growth and Replication of Human Immunodeficiency Virus 1 (HIV-1).

PubMed

Zabihollahi, Rezvan; Pooshang Bagheri, Kamran; Keshavarz, Zohreh; Motevalli, Fatemeh; Bahramali, Golnaz; Siadat, Seyed Davar; Momen, Seyed Bahman; Shahbazzadeh, Delavar; Aghasadeghi, Mohammad Reza

2016-11-01

During the recent years, significant progress has been achieved on development of novel anti-viral drugs. Natural products are assumed as the potential sources of novel anti-viral drugs; therefore, there are some previous studies reporting the anti-viral compounds from venomous animals. Based on the significant value for tracing of non-toxic anti-viral agents from natural resources, this study was aimed to investigate the anti-viral activity of some HPLC purified fractions derived from the venom of Iranian scorpion, Hemiscorpius lepturus, against human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1). H. Lepturus crude venom was subjected to reverse phase HPLC analysis to determine its active components precisely where four dominant fractions obtained at retention time of 156-160 minutes. The phospholipase A2 and hemolytic activities of the purified fractions were first evaluated. Then the anti-viral activity was measured using single cycle HIV (NL4-3) replication and HSV (KOS) plaque reduction assays. The H. lepturus crude venom inhibited HIV replication by 73% at the concentration of 200 µg/ml, while it did not show significant anti-HSV activity. It also inhibited the cell-free viral particles in a virucidal assay, while it showed no toxicity for the target cells in a proliferation assay. The four HPLC fractions purified from H. lepturus inhibited HIV with IC50 of 20 µg/ml. H. lepturus venom contains components with considerable anti-HIV activity insofar as it has virucidal activity that offers a novel therapeutic approach against HIV infection. Our results suggest a promising pilot for anti-HIV drug discovery with H. lepturus scorpion venom.

Antiviral potential of a diterpenoid compound sugiol from Metasequoia glyptostroboides.

PubMed

Bajpai, Vivek K; Kim, Na-Hyung; Kim, Kangmin; Kang, Sun Chul

2016-05-01

This research reports first time antiviral activity of sugiol, a diterpenoid isolated from Metasequoia glyptostroboides in terms of its ability to inhibit in vitro growth of H1N1 influenza virus. Antiviral potential of sugiol was evaluated through hcytopathogenic reduction assay using Madin-Darby canine kidney (MDCK) cell line. Sugiol (500 μg/ml) was found to exhibit considerable anti-cytopathic effect on MDCK cell line confirming its antiviral efficacy against H1N1 influenza virus. These findings strongly reinforce the suggestion that sugiol could be a candidate of choice in combinational regimen with potential antiviral efficacy.

Searching for Interferon-Induced Genes That Inhibit Hepatitis B Virus Replication in Transgenic Mouse Hepatocytes†

PubMed Central

Wieland, Stefan F.; Vega, Raquel G.; Müller, Rolf; Evans, Claire F.; Hilbush, Brian; Guidotti, Luca G.; Sutcliffe, J. Gregor; Schultz, Peter G.; Chisari, Francis V.

2003-01-01

We have previously shown that alpha/beta interferon (IFN-α/β) and IFN-γ inhibit hepatitis B virus (HBV) replication noncytopathically in the livers of HBV transgenic mice and in hepatocyte cell lines derived from these mice. The present study was designed to identify transcriptionally controlled hepatocellular genes that are tightly associated with the inhibition of HBV replication and that might, therefore, mediate the antiviral effect of these cytokines. Twenty-nine genes were identified, many of which have known or potential antiviral activity. Notably, multiple components of the immunoproteasome and ubiquitin-like proteins were strongly induced by both IFN-α/β and IFN-γ, as were a number of GTP-binding proteins, including GTPases with known antiviral activity, chemokines, signaling molecules, and miscellaneous genes associated with antigen processing, DNA-binding, or cochaperone activity and several expressed sequence tags. The results suggest that one or more members of this relatively small subset of genes may mediate the antiviral effect of IFN-α/β and IFN-γ against HBV. We have already exploited this information by demonstrating that the antiviral activity of IFN-α/β and IFN-γ is proteasome dependent. PMID:12502840

Targeting Innate Immunity for Antiviral Therapy through Small Molecule Agonists of the RLR Pathway

PubMed Central

Pattabhi, Sowmya; Wilkins, Courtney R.; Dong, Ran; Knoll, Megan L.; Posakony, Jeffrey; Kaiser, Shari; Mire, Chad E.; Wang, Myra L.; Ireton, Renee C.; Geisbert, Thomas W.; Bedard, Kristin M.; Iadonato, Shawn P.

2015-01-01

ABSTRACT The cellular response to virus infection is initiated when pathogen recognition receptors (PRR) engage viral pathogen-associated molecular patterns (PAMPs). This process results in induction of downstream signaling pathways that activate the transcription factor interferon regulatory factor 3 (IRF3). IRF3 plays a critical role in antiviral immunity to drive the expression of innate immune response genes, including those encoding antiviral factors, type 1 interferon, and immune modulatory cytokines, that act in concert to restrict virus replication. Thus, small molecule agonists that can promote IRF3 activation and induce innate immune gene expression could serve as antivirals to induce tissue-wide innate immunity for effective control of virus infection. We identified small molecule compounds that activate IRF3 to differentially induce discrete subsets of antiviral genes. We tested a lead compound and derivatives for the ability to suppress infections caused by a broad range of RNA viruses. Compound administration significantly decreased the viral RNA load in cultured cells that were infected with viruses of the family Flaviviridae, including West Nile virus, dengue virus, and hepatitis C virus, as well as viruses of the families Filoviridae (Ebola virus), Orthomyxoviridae (influenza A virus), Arenaviridae (Lassa virus), and Paramyxoviridae (respiratory syncytial virus, Nipah virus) to suppress infectious virus production. Knockdown studies mapped this response to the RIG-I-like receptor pathway. This work identifies a novel class of host-directed immune modulatory molecules that activate IRF3 to promote host antiviral responses to broadly suppress infections caused by RNA viruses of distinct genera. IMPORTANCE Incidences of emerging and reemerging RNA viruses highlight a desperate need for broad-spectrum antiviral agents that can effectively control infections caused by viruses of distinct genera. We identified small molecule compounds that can selectively activate IRF3 for the purpose of identifying drug-like molecules that can be developed for the treatment of viral infections. Here, we report the discovery of a hydroxyquinoline family of small molecules that can activate IRF3 to promote cellular antiviral responses. These molecules can prophylactically or therapeutically control infection in cell culture by pathogenic RNA viruses, including West Nile virus, dengue virus, hepatitis C virus, influenza A virus, respiratory syncytial virus, Nipah virus, Lassa virus, and Ebola virus. Our study thus identifies a class of small molecules with a novel mechanism to enhance host immune responses for antiviral activity against a variety of RNA viruses that pose a significant health care burden and/or that are known to cause infections with high case fatality rates. PMID:26676770

Gemcitabine and Nucleos(t)ide Synthesis Inhibitors Are Broad-Spectrum Antiviral Drugs that Activate Innate Immunity.

PubMed

Shin, Hye Jin; Kim, Chonsaeng; Cho, Sungchan

2018-04-20

Nucleoside analogs have been frequently identified as antiviral agents. In recent years, gemcitabine, a cytidine analog in clinical use for the treatment of many solid tumors, was also shown to have antiviral activity against a broad range of viruses. Nucleoside analogs generally interfere with cellular nucleos(t)ide synthesis pathways, resulting in the depletion or imbalance of (d)NTP pools. Intriguingly, a few recent reports have shown that some nucleoside analogs, including gemcitabine, activated innate immunity, inducing the expression of interferon-stimulated genes, through nucleos(t)ide synthesis inhibition. The precise crosstalk between these two independent processes remains to be determined. Nonetheless, we summarize the current knowledge of nucleos(t)ide synthesis inhibition-related innate immunity and propose it as a newly emerging antiviral mechanism of nucleoside analogs.

Antiviral flavonoids from the seeds of Aesculus chinensis.

PubMed

Wei, Feng; Ma, Shuang-Cheng; Ma, Lin-Yun; But, Paul Pui-Hay; Lin, Rui-Chao; Khan, Ikhlas A

2004-04-01

A bioassay-guided fractionation of an ethanol extract of the seeds of Aesculus chinensis led to the isolation of two new flavanoids (1 and 2), along with eight known ones (3-10). The structures of the new compounds were elucidated by spectroscopic methods including 2D NMR. All compounds were tested for antiviral activity against respiratory syncytial virus (RSV), parainfluenza virus type 3 (PIV 3), and influenza virus type A (Flu A). Compounds 1, 2, and 6 showed significant antiviral activities against RSV with IC(50) values of 4.5, 6.7, and 4.1 microg/mL and selective index (SI) values of 15.8, 32, and 63.8, respectively. Compound 8 demonstrated significant antiviral activity against Flu A with an IC(50) of 24.5 microg/mL and a SI of 16.0, respectively.

Heat shock cognate 71 (HSC71) regulates cellular antiviral response by impairing formation of VISA aggregates.

PubMed

Liu, Zhigang; Wu, Shu-Wen; Lei, Cao-Qi; Zhou, Qian; Li, Shu; Shu, Hong-Bing; Wang, Yan-Yi

2013-05-01

In response to viral infection, RIG-I-like RNA helicases detect viral RNA and signal through the mitochondrial adapter protein VISA. VISA activation leads to rapid activation of transcription factors IRF3 and NF-κB, which collaborate to induce transcription of type I interferon (IFN) genes and cellular antiviral response. It has been demonstrated that VISA is activated by forming prion-like aggregates. However, how this process is regulated remains unknown. Here we show that overexpression of HSC71 resulted in potent inhibition of virus-triggered transcription of IFNB1 gene and cellular antiviral response. Consistently, knockdown of HSC71 had opposite effects. HSC71 interacted with VISA, and negatively regulated virus-triggered VISA aggregation. These findings suggest that HSC71 functions as a check against VISA-mediated antiviral response.

Reciprocal inhibition between intracellular antiviral signaling and the RNAi machinery in mammalian cells

PubMed Central

Seo, Gil Ju; Kincaid, Rodney P.; Phanaksri, Teva; Burke, James M.; Pare, Justin M.; Cox, Jennifer E.; Hsiang, Tien-Ying; Krug, Robert M.; Sullivan, Christopher S.

2013-01-01

SUMMARY RNA interference (RNAi) is an established antiviral defense mechanism in plants and invertebrates. Whether RNAi serves a similar function in mammalian cells remains unresolved. We find that in some cell types, mammalian RNAi activity is reduced shortly after viral infection via poly ADP-ribosylation of the RNA induced silencing complex (RISC), a core component of RNAi. Well-established antiviral signaling pathways, including RIG-I/MAVS and RNAseL, contribute to inhibition of RISC. In the absence of virus infection, microRNAs repress interferon-stimulated genes (ISGs) associated with cell death and proliferation, thus maintaining homeostasis. Upon detection of intracellular pathogen-associated molecular patterns, RISC activity decreases, contributing to increased expression of ISGs. Our results suggest that unlike in lower eukaryotes, mammalian RISC is not antiviral in some contexts, but rather, RISC has been co-opted to negatively regulate toxic host antiviral effectors via microRNAs. PMID:24075860

Infection-specific phosphorylation of glutamyl-prolyl tRNA synthetase induces antiviral immunity

PubMed Central

Lee, Eun-Young; Lee, Hyun-Cheol; Kim, Hyun-Kwan; Jang, Song Yee; Park, Seong-Jun; Kim, Yong-Hoon; Kim, Jong Hwan; Hwang, Jungwon; Kim, Jae-Hoon; Kim, Tae-Hwan; Arif, Abul; Kim, Seon-Young; Choi, Young-Ki; Lee, Cheolju; Lee, Chul-Ho; Jung, Jae U; Fox, Paul L; Kim, Sunghoon; Lee, Jong-Soo; Kim, Myung Hee

2016-01-01

The mammalian cytoplasmic multi-tRNA synthetase complex (MSC) is a depot system that regulates non-translational cellular functions. Here we found that the MSC component glutamyl-prolyl-tRNA synthetase (EPRS) switched its function following viral infection and exhibited potent antiviral activity. Infection-specific phosphorylation of EPRS at Ser990 induced its dissociation from the MSC, after which it was guided to the antiviral signaling pathway, where it interacted with PCBP2, a negative regulator of mitochondrial antiviral signaling protein (MAVS) that is critical for antiviral immunity. This interaction blocked PCBP2-mediated ubiquitination of MAVS and ultimately suppressed viral replication. EPRS-haploid (Eprs+/−) mice showed enhanced viremia and inflammation and delayed viral clearance. This stimulus-inducible activation of MAVS by EPRS suggests an unexpected role for the MSC as a regulator of immune responses to viral infection. PMID:27595231

Antiviral activity of ovine interferon tau 4 against foot-and-mouth disease virus.

PubMed

Usharani, Jayaramaiah; Park, Sun Young; Cho, Eun-Ju; Kim, Chungsu; Ko, Young-Joon; Tark, Dongseob; Kim, Su-Mi; Park, Jong-Hyeon; Lee, Kwang-Nyeong; Lee, Myoung-Heon; Lee, Hyang-Sim

2017-07-01

Foot-and-mouth disease (FMD) is an economically important disease in most parts of the world and new therapeutic agents are needed to protect the animals before vaccination can trigger the host immune response. Although several interferons have been used for their antiviral activities against Foot-and-mouth disease virus (FMDV), ovine interferon tau 4 (OvIFN-τ4), with a broad-spectrum of action, cross-species antiviral activity, and lower incidence of toxicity in comparison to other type І interferons, has not yet been evaluated for this indication. This is the first study to evaluate the antiviral activity of OvIFN-τ4 against various strains of FMDV. The effective anti-cytopathic concentration of OvIFN-τ4 and its effectiveness pre- and post-infection with FMDV were tested in vitro in LFBK cells. In vivo activity of OvIFN-τ4 was then confirmed in a mouse model of infection. OvIFN-τ4 at a concentration of 500 ng, protected mice until 5days post-FMDV challenge and provided 90% protection for 10 days following FMDV challenge. These results suggest that OvIFN-τ4 could be used as an alternative to other interferons or antiviral agents at the time of FMD outbreak. Copyright © 2017. Published by Elsevier B.V.

Deletion of Cytoplasmic Double-Stranded RNA Sensors Does Not Uncover Viral Small Interfering RNA Production in Human Cells.

PubMed

Schuster, Susan; Tholen, Lotte E; Overheul, Gijs J; van Kuppeveld, Frank J M; van Rij, Ronald P

2017-01-01

Antiviral immunity in insects and plants is mediated by the RNA interference (RNAi) pathway in which viral long double-stranded RNA (dsRNA) is processed into small interfering RNAs (siRNAs) by Dicer enzymes. Although this pathway is evolutionarily conserved, its involvement in antiviral defense in mammals is the subject of debate. In vertebrates, recognition of viral RNA induces a sophisticated type I interferon (IFN)-based immune response, and it has been proposed that this response masks or inhibits antiviral RNAi. To test this hypothesis, we analyzed viral small RNA production in differentiated cells deficient in the cytoplasmic RNA sensors RIG-I and MDA5. We did not detect 22-nucleotide (nt) viral siRNAs upon infection with three different positive-sense RNA viruses. Our data suggest that the depletion of cytoplasmic RIG-I-like sensors is not sufficient to uncover viral siRNAs in differentiated cells. IMPORTANCE The contribution of the RNA interference (RNAi) pathway in antiviral immunity in vertebrates has been widely debated. It has been proposed that RNAi possesses antiviral activity in mammalian systems but that its antiviral effect is masked by the potent antiviral interferon response in differentiated mammalian cells. In this study, we show that inactivation of the interferon response is not sufficient to uncover antiviral activity of RNAi in human epithelial cells infected with three wild-type positive-sense RNA viruses.

Antiviral Effect of Sub Fraction Cassia alata Leaves Extract to Dengue Virus Serotype-2 strain New Guinea C in Human Cell Line Huh-7 it-1

NASA Astrophysics Data System (ADS)

Angelina, Marissa; Hanafi, Muhammad; Suyatna, Franciscus D.; Mirawati S., T.; Ratnasari, Shirley; Ernawati Dewi, Beti

2017-12-01

Dengue virus (DENV) is one of the most common viral infections found Indonesia and tropical regions, and no specific antiviral for DENV. Indonesia has several of herbal medicine that were not explored of their potency as antiviral DENV. This study was done to evaluate the activity and toxicity of 4 derived fractions: Hexane (CA1), ethyl acetate (CA2), buthanol (CA3 ) and water (CA4) of Cassia alata leaf extract (CA) as an antiviral drug to DENV. The DENV was treated with various concentration of extract and added to Huh-7 it-1. The decrease of virus titer was determined by Focus assay. The toxicity of extract was measured by MTT assay. In our previous study, we found that CA on Huh-7 cells showed IC50, CC50 and SI values of <10 μg/mL, 323.45 μg/mL, and more than 32.3, respectively. For the fractions, CA3 showed best antiviral activity among other, with IC50, CC50 and SI of <10 μg/mL, 645.8 μg/mL, and more than 64.5, respectively. CA and CA3 were proven to possess antiviral activity that is potent when tested against DENV-2. Future study was needed to explore the inhibition mechanism and compound of CA that have potency as antiviral drug to DENV.

Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III IFN-augmenting activity in airway epithelium.

PubMed

Porter, James D; Watson, Jennifer; Roberts, Lee R; Gill, Simren K; Groves, Helen; Dhariwal, Jaideep; Almond, Mark H; Wong, Ernie; Walton, Ross P; Jones, Lyn H; Tregoning, John; Kilty, Iain; Johnston, Sebastian L; Edwards, Michael R

2016-10-01

Exacerbations of asthma and COPD are triggered by rhinoviruses. Uncontrolled inflammatory pathways, pathogenic bacterial burden and impaired antiviral immunity are thought to be important factors in disease severity and duration. Macrolides including azithromycin are often used to treat the above diseases, but exhibit variable levels of efficacy. Inhaled corticosteroids are also readily used in treatment, but may lack specificity. Ideally, new treatment alternatives should suppress unwanted inflammation, but spare beneficial antiviral immunity. In the present study, we screened 225 novel macrolides and tested them for enhanced antiviral activity against rhinovirus, as well as anti-inflammatory activity and activity against Gram-positive and Gram-negative bacteria. Primary bronchial epithelial cells were grown from 10 asthmatic individuals and the effects of macrolides on rhinovirus replication were also examined. Another 30 structurally similar macrolides were also examined. The oleandomycin derivative Mac5, compared with azithromycin, showed superior induction (up to 5-fold, EC50 = 5-11 μM) of rhinovirus-induced type I IFNβ, type III IFNλ1 and type III IFNλ2/3 mRNA and the IFN-stimulated genes viperin and MxA, yet had no effect on IL-6 and IL-8 mRNA. Mac5 also suppressed rhinovirus replication at 48 h, proving antiviral activity. Mac5 showed antibacterial activity against Gram-positive Streptococcus pneumoniae; however, it did not have any antibacterial properties compared with azithromycin when used against Gram-negative Escherichia coli (as a model organism) and also the respiratory pathogens Pseudomonas aeruginosa and non-typeable Haemophilus influenzae. Further non-toxic Mac5 derivatives were identified with various anti-inflammatory, antiviral and antibacterial activities. The data support the idea that macrolides have antiviral properties through a mechanism that is yet to be ascertained. We also provide evidence that macrolides can be developed with anti-inflammatory, antibacterial and antiviral activity and show surprising versatility depending on the clinical need. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

In vitro evaluation of the antiviral properties of Shilajit and investigation of its mechanisms of action.

PubMed

Cagno, Valeria; Donalisio, Manuela; Civra, Andrea; Cagliero, Cecilia; Rubiolo, Patrizia; Lembo, David

2015-05-26

Shilajit, a herbomineral substance exuded from rocks in steep mountainous regions, has been used for thousands of years by the Indian Ayurvedic and Siddha systems of traditional medicine to relieve ailments and enhance quality of life. Although a large number of therapeutic properties have been ascribed to Shilajit, its therapeutic potential is still largely unexplored by modern research and many of its claimed bioactivities lack scientific validation. The present study was undertaken to investigate the antiviral activity of Shilajit against a panel of viruses including herpes simplex type 1 and 2 (HSV-1, HSV-2), human cytomegalovirus (HCMV), human respiratory syncytial virus (RSV), human rotavirus (HRV), and vesicular stomatitis virus (VSV). The antiviral activity of Shilajit was assayed in vitro by plaque reduction and virus yield assays and the major mechanism of action was investigated by virucidal and time-of-addition assays. Shilajit exhibited a dose-dependent inhibitory activity against HSV1, HSV2, HCMV, and RSV infectivity in vitro (EC50 values: 31.08μg/ml, 12.85μg/ml, 34.54μg/ml, and 30.35μg/ml, respectively), but was inactive against HRV and VSV. Humic acid, a constituent of Shilajit, displayed the same spectrum of activity. Partial virus inactivation and interference with virus attachment were both found to contribute to the antiviral activity of Shilajit. The results of the present study demonstrate that Shilajit is endowed with broad, yet specific, antiviral activity in vitro and constitutes a natural source of antiviral substances. Further work remains to be done to assess its efficacy in vivo. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Synthesis, Antiviral and Cytotoxic Activity of Novel Terpenyl Hybrid Molecules Prepared by Click Chemistry.

PubMed

Pertino, Mariano Walter; Petrera, Erina; Alché, Laura Edith; Schmeda-Hirschmann, Guillermo

2018-06-03

Naturally occurring terpenes were combined by click reactions to generate sixteen hybrid molecules. The diterpene imbricatolic acid (IA) containing an azide group was used as starting compound for the synthesis of all the derivatives. The alkyne group in the terpenes cyperenoic acid, dehydroabietinol, carnosic acid γ-lactone, ferruginol, oleanolic acid and aleuritolic acid was obtained by esterification using appropriate alcohols or acids. The hybrid compounds were prepared by combining the IA azide function with the different terpene-alkynes under click chemistry conditions. The cytotoxic activity of the terpene hybrids 1 ⁻ 16 was assessed against Vero cells and tumour cell lines (HEP-2, C6 and Raw 264.7). Compounds 1 , 2 , 3 and 7 showed cytotoxic activity against the tested cell lines. The antiviral activity of the compounds was evaluated against HSV-1 KOS, Field and B2006 strain. For the pairs of hybrid compounds formed between IA-diterpene (compounds 3 ⁻ 8 , except for compound 7 ), a moderate activity was observed against the three HSV-1 strains with an interesting selectivity index (SI ≥10, SI = CC 50 /CE 50 ) for some compounds.

Anti-enterovirus 71 activity screening of chinese herbs with anti-infection and inflammation activities.

PubMed

Lin, Tzou-Yien; Liu, Yi-Chun; Jheng, Jia-Rong; Tsai, Hui-Ping; Jan, Jia-Tsrong; Wong, Wen-Rou; Horng, Jim-Tong

2009-01-01

Antipyretic and toxin-eliminating traditional Chinese herbs are believed to possess antiviral activity. In this study, we screened extracts of 22 herbs for activity against enterovirus 71 (EV71). We found that only extracts of Houttuynia cordata Thunb. could neutralize EV71-induced cytopathic effects in Vero cells. The 50% inhibitory concentration of H. cordata extract for EV71 was 125.92 +/- 27.84 mug/ml. Antiviral screening of herb extracts was also conducted on 3 genotypes of EV71, coxsackievirus A16 and echovirus 9. H. cordata extract had the highest activity against genotype A of EV71. A plaque reduction assay showed that H. cordata extract significantly reduced plaque formation. Viral protein expression, viral RNA synthesis and virus-induced caspase 3 activation were inhibited in the presence of H. cordata extract, suggesting that it affected apoptotic processes in EV71-infected Vero cells by inhibiting viral replication. The antiviral activity of H. cordata extract was greater in cells pretreated with extract than those treated after infection. We conclude that H. cordata extract has antiviral activity, and it offers a potential to develop a new anti-EV71 agent.

A 2,5-Dihydroxybenzoic Acid–Gelatin Conjugate: The Synthesis, Antiviral Activity and Mechanism of Antiviral Action Against Two Alphaherpesviruses

PubMed Central

Lisov, Alexander; Vrublevskaya, Veronika; Lisova, Zoy; Leontievsky, Alexey; Morenkov, Oleg

2015-01-01

Various natural and synthetic polyanionic polymers with different chemical structures are known to exhibit potent antiviral activity in vitro toward a variety of enveloped viruses and may be considered as promising therapeutic agents. A water-soluble conjugate of 2,5-dihydroxybezoic acid (2,5-DHBA) with gelatin was synthesized by laccase-catalyzed oxidation of 2,5-DHBA in the presence of gelatin, and its antiviral activity against pseudorabies virus (PRV) and bovine herpesvirus type 1 (BoHV-1), two members of the Alphaherpesvirinae subfamily, was studied. The conjugate produced no direct cytotoxic effect on cells, and did not inhibit cell growth at concentrations up to 1000 µg/mL. It exhibited potent antiviral activity against PRV (IC50, 1.5–15 µg/mL for different virus strains) and BoHV-1 (IC50, 0.5–0.7 µg/mL). When present during virus adsorption, the conjugate strongly inhibited the attachment of PRV and BoHV-1 to cells. The 2,5-DHBA–gelatin conjugate had no direct virucidal effect on the viruses and did not influence their penetration into cells, cell-to-cell spread, production of infectious virus particles in cells, and expression of PRV glycoproteins E and B. The results indicated that the 2,5-DHBA–gelatin conjugate strongly inhibits the adsorption of alphaherpesviruses to cells and can be a promising synthetic polymer for the development of antiviral formulations against alphaherpesvirus infections. PMID:26501311

TRIM25 in the Regulation of the Antiviral Innate Immunity.

PubMed

Martín-Vicente, María; Medrano, Luz M; Resino, Salvador; García-Sastre, Adolfo; Martínez, Isidoro

2017-01-01

TRIM25 is an E3 ubiquitin ligase enzyme that is involved in various cellular processes, including regulation of the innate immune response against viruses. TRIM25-mediated ubiquitination of the cytosolic pattern recognition receptor RIG-I is an essential step for initiation of the intracellular antiviral response and has been thoroughly documented. In recent years, however, additional roles of TRIM25 in early innate immunity are emerging, including negative regulation of RIG-I, activation of the melanoma differentiation-associated protein 5-mitochondrial antiviral signaling protein-TRAF6 antiviral axis and modulation of p53 levels and activity. In addition, the ability of TRIM25 to bind RNA may uncover new mechanisms by which this molecule regulates intracellular signaling and/or RNA virus replication.

Antiviral RNA Recognition and Assembly by RLR Family Innate Immune Sensors

PubMed Central

Bruns, Annie M.; Horvath, Curt M.

2014-01-01

Virus-encoded molecular signatures, such as cytosolic double-stranded or otherwise biochemically distinct RNA species, trigger cellular antiviral signaling. Cytoplasmic proteins recognize these non-self RNAs and activate signal transduction pathways that drive the expression of virus-induced genes, including the primary antiviral cytokine, IFNβ, and diverse direct and indirect antiviral effectors [1–4]. One important group of cytosolic RNA sensors known as the RIG-I like receptors (RLRs) is comprised of three proteins that are similar in structure and function. The RLR proteins, RIG-I, MDA5, and LGP2, share the ability to recognize nucleic acid signatures produced by virus infections and activate antiviral signaling. Emerging evidence indicates that RNA detection by RLRs culminates in the assembly of dynamic multimeric ribonucleoprotein (RNP) complexes. These RNPs can act as signaling platforms that are capable of propagating and amplifying antiviral signaling responses. Despite their common domain structures and similar abilities to induce antiviral responses, the RLRs differ in their enzymatic properties, their intrinsic abilities to recognize RNA, and their ability to assemble into filamentous complexes. This molecular specialization has enabled the RLRs to recognize and respond to diverse virus infections, and to mediate both unique and overlapping functions in immune regulation [5, 6]. PMID:25081315

Pharmacological cdk inhibitor R-Roscovitine suppresses JC virus proliferation

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

Orba, Yasuko; Laboratory of Molecular and Cellular Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, 060-8638, Sapporo; Research Fellow of the Japan Society for the Promotion of Science

2008-01-05

The human Polyomavirus JC virus (JCV) utilizes cellular proteins for viral replication and transcription in the host cell nucleus. These cellular proteins represent potential targets for antiviral drugs against the JCV. In this study, we examined the antiviral effects of the pharmacological cyclin-dependent kinase (cdk) inhibitor R-Roscovitine, which has been shown to have antiviral activity against other viruses. We found that Roscovitine significantly inhibited the viral production and cytopathic effects of the JCV in a JCV-infected cell line. Roscovitine attenuated the transcriptional activity of JCV late genes, but not early genes, and also prevented viral replication via inhibiting phosphorylation ofmore » the viral early protein, large T antigen. These data suggest that the JCV requires cdks to transcribe late genes and to replicate its own DNA. That Roscovitine exhibited antiviral activity in JCV-infected cells suggests that Roscovitine might have therapeutic utility in the treatment of progressive multifocal leukoencephalopathy (PML)« less

Mechanism of TRIM25 Catalytic Activation in the Antiviral RIG-I Pathway

PubMed Central

Sanchez, Jacint G.; Chiang, Jessica J.; Sparrer, Konstantin M.J.; Alam, Steven L.; Chi, Michael; Roganowicz, Marcin D.; Sankaran, Banumathi; Gack, Michaela U.; Pornillos, Owen

2016-01-01

SUMMARY Antiviral response pathways induce interferon by higher-order assembly of signaling complexes called signalosomes. Assembly of the RIG-I signalosome is regulated by K63-linked polyubiquitin chains, which are synthesized by the E3 ubiquitin ligase, TRIM25. We have previously shown that the TRIM25 coiled-coil domain is a stable, antiparallel dimer that positions two catalytic RING domains on opposite ends of an elongated rod. We now show that the RING domain is a separate self-association motif that engages ubiquitin-conjugated E2 enzymes as a dimer. RING dimerization is required for catalysis, TRIM25-mediated RIG-I ubiquitination, interferon induction, and antiviral activity. We also provide evidence that RING dimerization and E3 ligase activity are promoted by binding of the TRIM25 SPRY domain to the RIG-I effector domain. These results indicate that TRIM25 actively participates in higher-order assembly of the RIG-I signalosome and helps to fine-tune the efficiency of the RIG-I-mediated antiviral response. PMID:27425606

Baicalin, a metabolite of baicalein with antiviral activity against dengue virus

PubMed Central

Moghaddam, Ehsan; Teoh, Boon-Teong; Sam, Sing-Sin; Lani, Rafidah; Hassandarvish, Pouya; Chik, Zamri; Yueh, Andrew; Abubakar, Sazaly; Zandi, Keivan

2014-01-01

Baicalin, a flavonoid derived from Scutellaria baicalensis, is the main metabolite of baicalein released following administration in different animal models and human. We previously reported the antiviral activity of baicalein against dengue virus (DENV). Here, we examined the anti-DENV properties of baicalin in vitro, and described the inhibitory potentials of baicalin at different steps of DENV-2 (NGC strain) replication. Our in vitro antiviral experiments showed that baicalin inhibited virus replication at IC50 = 13.5 ± 0.08 μg/ml with SI = 21.5 following virus internalization by Vero cells. Baicalin exhibited virucidal activity against DENV-2 extracellular particles at IC50 = 8.74 ± 0.08 μg/ml and showed anti-adsorption effect with IC50 = 18.07 ± 0.2 μg/ml. Our findings showed that baicalin as the main metabolite of baicalein exerting in vitro anti-DENV activity. Further investigations on baicalein and baicalin to deduce its antiviral therapeutic effects are warranted. PMID:24965553

First-in-Human Trial of MIV-150 and Zinc Acetate Coformulated in a Carrageenan Gel: Safety, Pharmacokinetics, Acceptability, Adherence, and Pharmacodynamics

PubMed Central

Hoesley, Craig J.; Plagianos, Marlena; Hoskin, Elena; Zhang, Shimin; Teleshova, Natalia; Alami, Mohcine; Novak, Lea; Kleinbeck, Kyle R.; Katzen, Lauren L.; Zydowsky, Thomas M.; Fernández-Romero, José A.; Creasy, George W.

2016-01-01

Objective: To evaluate the safety and pharmacokinetics of MIV-150 and zinc acetate in a carrageenan gel (PC-1005). Acceptability, adherence, and pharmacodynamics were also explored. Design: A 3-day open-label safety run-in (n = 5) preceded a placebo-controlled, double-blind trial in healthy, HIV-negative, abstinent women randomized (4:1) to vaginally apply 4 mL of PC-1005 or placebo once daily for 14 days. Methods: Assessments included physical examinations, safety labs, colposcopy, biopsies, cervicovaginal lavages (CVLs), and behavioral questionnaires. MIV-150 (plasma, CVL, tissue), zinc (plasma, CVL), and carrageenan (CVL) concentrations were determined with LC-MS/MS, ICP-MS, and ELISA, respectively. CVL antiviral activity was measured using cell-based assays. Safety, acceptability, and adherence were analyzed descriptively. Pharmacokinetic parameters were calculated using noncompartmental techniques and actual sampling times. CVL antiviral EC50 values were calculated using a dose–response inhibition analysis. Results: Participants (n = 20) ranged from 19–44 years old; 52% were black or African American. Among those completing the trial (13/17, PC-1005; 3/3, placebo), 11/17 reported liking the gel overall; 7 recommended reducing the volume. Adverse events, which were primarily mild and/or unrelated, were comparable between groups. Low systemic MIV-150 levels were observed, without accumulation. Plasma zinc levels were unchanged from baseline. Seven of seven CVLs collected 4-hour postdose demonstrated antiviral (HIV, human papillomavirus) activity. High baseline CVL anti–herpes-simplex virus type-2 (HSV-2) activity precluded assessment of postdose activity. Conclusions: PC-1005 used vaginally for 14 days was well tolerated. Low systemic levels of MIV-150 were observed. Plasma zinc levels were unchanged. Postdose CVLs had anti-HIV and anti–human papillomavirus activity. These data warrant further development of PC-1005 for HIV and sexually transmitted infection prevention. PMID:27437826

A high throughput screen identifies benzoquinoline compounds as inhibitors of Ebola virus replication.

PubMed

Luthra, Priya; Liang, Jue; Pietzsch, Colette A; Khadka, Sudip; Edwards, Megan R; Wei, Shuguang; De, Sampriti; Posner, Bruce; Bukreyev, Alexander; Ready, Joseph M; Basler, Christopher F

2018-02-01

Ebola virus (EBOV) is an enveloped negative-sense, single-stranded RNA virus of the filovirus family that causes severe disease in humans. Approved therapies for EBOV disease are lacking. EBOV RNA synthesis is carried out by a virus-encoded complex with RNA-dependent RNA polymerase activity that is required for viral propagation. This complex and its activities are therefore potential antiviral targets. To identify potential lead inhibitors of EBOV RNA synthesis, a library of small molecule compounds was screened against a previously established assay of EBOV RNA synthesis, the EBOV minigenome assay (MGA), in 384 well microplate format. The screen identified 56 hits that inhibited EBOV MGA activity by more than 70% while exhibiting less than 20% cell cytotoxicity. Inhibitory chemical scaffolds included angelicin derivatives, derivatives of the antiviral compound GSK983 and benzoquinolines. Structure-activity relationship (SAR) studies of the benzoquinoline scaffold produced ∼50 analogs and led to identification of an optimized compound, SW456, with a submicromolar IC 50 in the EBOV MGA and antiviral activity against infectious EBOV in cell culture. The compound was also active against a MGA for another deadly filovirus, Marburg virus. It also exhibited antiviral activity towards a negative-sense RNA virus from the rhabdovirus family, vesicular stomatitis virus, and a positive-sense RNA virus, Zika virus. Overall, these data demonstrate the potential of the EBOV MGA to identify anti-EBOV compounds and identifies the benzoquinoline series as a broad-spectrum antiviral lead. Copyright © 2017. Published by Elsevier B.V.

CMV Infection in Bone Marrow and Solid Organ Transplant Patients in the Era of Antiviral Prophylaxis.

PubMed

Hebart, Holger; Jahn, Gerhard; Sinzger, Christian; Kanz, Lothar; Einsele, Hermann

2000-02-01

Recent developments in the diagnosis and therapy of cytomegalovirus (CMV) infection have helped to reduce CMV-associated morbidity and mortality following allogeneic bone marrow and solid organ transplantation. The clinical symptoms of active CMV infection and the prevalence of life-threatening CMV disease vary widely between different patient populations according to the type of transplant and the intensity of immunosuppression employed. Antiviral prophylaxis with aciclovir, valaciclovir and ganciclovir has been shown to reduce CMV infection and disease following organ transplantation. Antiviral drugs, in particular ganciclovir and foscarnet, have varying sideeffects, however, and antiviral resistance due to prolonged administration of ganciclovir and foscarnet has been reported recently. Short courses of pre-emptive antiviral therapy for documented CMV infection help to reduce the duration and sideeffects of therapy, offering an alternative strategy to antiviral prophylaxis. Studies are required to compare the efficacy and costs of antiviral prophylaxis with pre-emptive therapy.

Virucidal activity of a scorpion venom peptide variant mucroporin-M1 against measles, SARS-CoV and influenza H5N1 viruses.

PubMed

Li, Qiaoli; Zhao, Zhenhuan; Zhou, Dihan; Chen, Yaoqing; Hong, Wei; Cao, Luyang; Yang, Jingyi; Zhang, Yan; Shi, Wei; Cao, Zhijian; Wu, Yingliang; Yan, Huimin; Li, Wenxin

2011-07-01

Outbreaks of SARS-CoV, influenza A (H5N1, H1N1) and measles viruses in recent years have raised serious concerns about the measures available to control emerging and re-emerging infectious viral diseases. Effective antiviral agents are lacking that specifically target RNA viruses such as measles, SARS-CoV and influenza H5N1 viruses, and available vaccinations have demonstrated variable efficacy. Therefore, the development of novel antiviral agents is needed to close the vaccination gap and silence outbreaks. We previously identified mucroporin, a cationic host defense peptide from scorpion venom, which can effectively inhibit standard bacteria. The optimized mucroporin-M1 can inhibit gram-positive bacteria at low concentrations and antibiotic-resistant pathogens. In this investigation, we further tested mucroporin and the optimized mucroporin-M1 for their antiviral activity. Surprisingly, we found that the antiviral activities of mucroporin-M1 against measles, SARS-CoV and influenza H5N1 viruses were notably increased with an EC₅₀ of 7.15 μg/ml (3.52 μM) and a CC₅₀ of 70.46 μg/ml (34.70 μM) against measles virus, an EC₅₀ of 14.46 μg/ml (7.12 μM) against SARS-CoV and an EC₅₀ of 2.10 μg/ml (1.03 μM) against H5N1, while the original peptide mucroporin showed no antiviral activity against any of these three viruses. The inhibition model could be via a direct interaction with the virus envelope, thereby decreasing the infectivity of virus. This report provides evidence that host defense peptides from scorpion venom can be modified for antiviral activity by rational design and represents a practical approach for developing broad-spectrum antiviral agents, especially against RNA viruses. Copyright © 2011 Elsevier Inc. All rights reserved.

Identification of transformation products of antiviral drugs formed during biological wastewater treatment and their occurrence in the urban water cycle.

PubMed

Funke, Jan; Prasse, Carsten; Ternes, Thomas A

2016-07-01

The fate of five antiviral drugs (abacavir, emtricitabine, ganciclovir, lamivudine and zidovudine) was investigated in biological wastewater treatment. Investigations of degradation kinetics were accompanied by the elucidation of formed transformation products (TPs) using activated sludge lab experiments and subsequent LC-HRMS analysis. Degradation rate constants ranged between 0.46 L d(-1) gSS(-1) (zidovudine) and 55.8 L d(-1) gSS(-1) (abacavir). Despite these differences of the degradation kinetics, the same main biotransformation reaction was observed for all five compounds: oxidation of the terminal hydroxyl-moiety to the corresponding carboxylic acid (formation of carboxy-TPs). In addition, the oxidation of thioether moieties to sulfoxides was observed for emtricitabine and lamivudine. Antiviral drugs were detected in influents of municipal wastewater treatment plants (WWTPs) with concentrations up to 980 ng L(-1) (emtricitabine), while in WWTP effluents mainly the TPs were found with concentration levels up to 1320 ng L(-1) (carboxy-abacavir). Except of zidovudine none of the original antiviral drugs were detected in German rivers and streams, whereas the concentrations of the TPs ranged from 16 ng L(-1) for carboxy-lamivudine up to 750 ng L(-1) for carboxy-acyclovir. These concentrations indicate an appreciable portion from WWTP effluents present in rivers and streams, as well as the high environmental persistence of the carboxy-TPs. As a result three of the carboxylic TPs were detected in finished drinking water. Copyright © 2016 Elsevier Ltd. All rights reserved.

Upregulation of the Suppressors of Cytokine Signaling 1 and 3 Is Associated with Arrest of Phosphorylated-STAT1 Nuclear Importation and Reduced Innate Response in Denguevirus-Infected Macrophages.

PubMed

Estrada-Jiménez, Tania; Millán-Pérez Peña, Lourdes; Flores-Mendoza, Lilian; Sedeño-Monge, Virginia; Santos-López, Gerardo; Rosas-Murrieta, Nora; Reyes-Carmona, Sandra; Terán-Cabanillas, Eli; Hernández, Jesus; Herrera-Camacho, Irma; Vallejo-Ruiz, Verónica; Reyes-Leyva, Julio

2016-03-01

To clarify whether the suppressors of cytokine signaling (SOCS) are associated with denguevirus (DENV) evasion of the antiviral response, we analyzed the expression kinetics of SOCS1 and SOCS3 and of the antiviral genes MxA and OAS during DENV infection of U937 macrophages that were or not treated with interferon (IFN)-α. DENV infection produced a viral titer three times higher in untreated than in IFN-α-treated cells (p < 0.001 at 72 h postinfection [p.i.]). Partial inhibition of DENV replication was associated with reduced expression of MxA and OAS antiviral genes as well as higher SOCS1 and SOCS3 expression in DENV-infected cells than in cells treated only with IFN-α. Complete loss of phosphorylated-signal transducer and activator of transcription (p-STAT)2 and reduced nuclear importation of p-STAT1 were observed in DENV-infected cells compared to IFN-α treatment that induced p-STAT1 and p-STAT2. Our data thus suggest that overexpression of SOCS1 and SOCS3 induced by DENV infection leads to impairment of antiviral response through the inhibition of STAT functionality.

The Mechanisms for Within-Host Influenza Virus Control Affect Model-Based Assessment and Prediction of Antiviral Treatment

PubMed Central

Cao, Pengxing

2017-01-01

Models of within-host influenza viral dynamics have contributed to an improved understanding of viral dynamics and antiviral effects over the past decade. Existing models can be classified into two broad types based on the mechanism of viral control: models utilising target cell depletion to limit the progress of infection and models which rely on timely activation of innate and adaptive immune responses to control the infection. In this paper, we compare how two exemplar models based on these different mechanisms behave and investigate how the mechanistic difference affects the assessment and prediction of antiviral treatment. We find that the assumed mechanism for viral control strongly influences the predicted outcomes of treatment. Furthermore, we observe that for the target cell-limited model the assumed drug efficacy strongly influences the predicted treatment outcomes. The area under the viral load curve is identified as the most reliable predictor of drug efficacy, and is robust to model selection. Moreover, with support from previous clinical studies, we suggest that the target cell-limited model is more suitable for modelling in vitro assays or infection in some immunocompromised/immunosuppressed patients while the immune response model is preferred for predicting the infection/antiviral effect in immunocompetent animals/patients. PMID:28933757

CRM1 Inhibitors for Antiviral Therapy

PubMed Central

Mathew, Cynthia; Ghildyal, Reena

2017-01-01

Infectious diseases are a major global concern and despite major advancements in medical research, still cause significant morbidity and mortality. Progress in antiviral therapy is particularly hindered by appearance of mutants capable of overcoming the effects of drugs targeting viral components. Alternatively, development of drugs targeting host proteins essential for completion of viral lifecycle holds potential as a viable strategy for antiviral therapy. Nucleocytoplasmic trafficking pathways in particular are involved in several pathological conditions including cancer and viral infections, where hijacking or alteration of function of key transporter proteins, such as Chromosome Region Maintenance1 (CRM1) is observed. Overexpression of CRM1-mediated nuclear export is evident in several solid and hematological malignancies. Interestingly, CRM1-mediated nuclear export of viral components is crucial in various stages of the viral lifecycle and assembly. This review summarizes the role of CRM1 in cancer and selected viruses. Leptomycin B (LMB) is the prototypical inhibitor of CRM1 potent against various cancer cell lines overexpressing CRM1 and in limiting viral infections at nanomolar concentrations in vitro. However, the irreversible shutdown of nuclear export results in high cytotoxicity and limited efficacy in vivo. This has prompted search for synthetic and natural CRM1 inhibitors that can potentially be developed as broadly active antivirals, some of which are summarized in this review. PMID:28702009

Activation of innate anti-viral immune response genes in symptomatic benign prostatic hyperplasia

PubMed Central

Madigan, Allison A.; Sobek, Kathryn M.; Cummings, Jessica L.; Green, William R.; Bacich, Dean J.; O’Keefe, Denise S.

2012-01-01

Benign Prostatic Hyperplasia (BPH)is the most common urologic disease in men over age 50. Symptoms include acute urinary retention, urgency to urinate and nocturia. For patients with severe symptoms, surgical treatment is used to remove the affected tissue. Interestingly, the presence of histologic BPH does not always correlate with symptoms. The molecular basis of symptomatic BPH and how it differs from asymptomatic BPH is unknown. Investigation into the molecular players involved in symptomatic BPH will likely give insight into novel therapeutic, and potentially preventative, targets. We determined the expression of genes involved in the innate anti-viral immune response in tissues from patients undergoing surgery to alleviate the symptoms of BPH, and compared the results to prostate tissue with histologic BPH, but from patients with few urinary issues (asymptomatic BPH). We found that expression of CFI, APOBEC3G, OAS2, and IFIT1, four genes whose protein products are involved in the innate anti-viral immune response, were significantly transcriptionally upregulated in symptomatic BPH. Additionally we observe hypomethylation and concomitant expression of ancient retroviral-like sequences, the LINE-1 retrotransposons, in symptomatic BPH when compared to normal prostate tissue. These findings merit further investigation into the anti-viral immune response in symptomatic BPH. PMID:22952051

Actinobacteria from Termite Mounds Show Antiviral Activity against Bovine Viral Diarrhea Virus, a Surrogate Model for Hepatitis C Virus

PubMed Central

Padilla, Marina Aiello; Rodrigues, Rodney Alexandre Ferreira; Bastos, Juliana Cristina Santiago; Martini, Matheus Cavalheiro; Barnabé, Ana Caroline de Souza; Kohn, Luciana Konecny; Uetanabaro, Ana Paula Trovatti; Bomfim, Getúlio Freitas; Afonso, Rafael Sanches; Fantinatti-Garboggini, Fabiana; Arns, Clarice Weis

2015-01-01

Extracts from termite-associated bacteria were evaluated for in vitro antiviral activity against bovine viral diarrhea virus (BVDV). Two bacterial strains were identified as active, with percentages of inhibition (IP) equal to 98%. Both strains were subjected to functional analysis via the addition of virus and extract at different time points in cell culture; the results showed that they were effective as posttreatments. Moreover, we performed MTT colorimetric assays to identify the CC50, IC50, and SI values of these strains, and strain CDPA27 was considered the most promising. In parallel, the isolates were identified as Streptomyces through 16S rRNA gene sequencing analysis. Specifically, CDPA27 was identified as S. chartreusis. The CDPA27 extract was fractionated on a C18-E SPE cartridge, and the fractions were reevaluated. A 100% methanol fraction was identified to contain the compound(s) responsible for antiviral activity, which had an SI of 262.41. GC-MS analysis showed that this activity was likely associated with the compound(s) that had a peak retention time of 5 min. Taken together, the results of the present study provide new information for antiviral research using natural sources, demonstrate the antiviral potential of Streptomyces chartreusis compounds isolated from termite mounds against BVDV, and lay the foundation for further studies on the treatment of HCV infection. PMID:26579205

Actinobacteria from Termite Mounds Show Antiviral Activity against Bovine Viral Diarrhea Virus, a Surrogate Model for Hepatitis C Virus.

PubMed

Padilla, Marina Aiello; Rodrigues, Rodney Alexandre Ferreira; Bastos, Juliana Cristina Santiago; Martini, Matheus Cavalheiro; Barnabé, Ana Caroline de Souza; Kohn, Luciana Konecny; Uetanabaro, Ana Paula Trovatti; Bomfim, Getúlio Freitas; Afonso, Rafael Sanches; Fantinatti-Garboggini, Fabiana; Arns, Clarice Weis

2015-01-01

Extracts from termite-associated bacteria were evaluated for in vitro antiviral activity against bovine viral diarrhea virus (BVDV). Two bacterial strains were identified as active, with percentages of inhibition (IP) equal to 98%. Both strains were subjected to functional analysis via the addition of virus and extract at different time points in cell culture; the results showed that they were effective as posttreatments. Moreover, we performed MTT colorimetric assays to identify the CC50, IC50, and SI values of these strains, and strain CDPA27 was considered the most promising. In parallel, the isolates were identified as Streptomyces through 16S rRNA gene sequencing analysis. Specifically, CDPA27 was identified as S. chartreusis. The CDPA27 extract was fractionated on a C18-E SPE cartridge, and the fractions were reevaluated. A 100% methanol fraction was identified to contain the compound(s) responsible for antiviral activity, which had an SI of 262.41. GC-MS analysis showed that this activity was likely associated with the compound(s) that had a peak retention time of 5 min. Taken together, the results of the present study provide new information for antiviral research using natural sources, demonstrate the antiviral potential of Streptomyces chartreusis compounds isolated from termite mounds against BVDV, and lay the foundation for further studies on the treatment of HCV infection.

A flavonoid compound library screen revealed potent antiviral activity of plant-derived flavonoids on human enterovirus A71 replication.

PubMed

Min, Nyo; Leong, Pok Thim; Lee, Regina Ching Hua; Khuan, Jeffery Seng Eng; Chu, Justin Jang Hann

2018-02-01

Hand Foot Mouth Disease (HFMD), resulting from human enterovirus A71 (HEVA71) infection can cause severe neurological complications leading to fatality in young children. Currently, there is no approved antiviral for therapeutic treatment against HEVA71 infection. In this study, a 500-compound flavonoid library was screened to identify potential inhibitors of HEVA71 using high-throughput immunofluorescence-based phenotypic screening method. Two lead flavonoid compounds, ST077124 and ST024734 at the non-cytotoxic concentration of 50 μM were found to be effective antivirals that inhibited replication of HEVA71, reducing infectious viral titers by 3.5 log 10  PFU/ml and 2.5 log 10  PFU/ml respectively. Our study revealed that ST077124 is a specific antiviral compound that inhibits human enteroviruses while ST024734 exhibited antiviral activity against human enteroviruses as well as dengue virus type-2. We also identified that both compounds affected the viral RNA transcription and translation machinery of HEVA71 but did not interfere with the viral internal ribosomal entry site (IRES) activity. Hence, our findings strongly suggest that ST077124 and ST024734 are effective antiviral compounds of minimal cytotoxicity and could serve as promising therapeutic agents against HEVA71 infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Probing Mercaptobenzamides as HIV Inactivators via Nucleocapsid Protein 7.

PubMed

Saha, Mrinmoy; Scerba, Michael T; Shank, Nathaniel I; Hartman, Tracy L; Buchholz, Caitlin A; Buckheit, Robert W; Durell, Stewart R; Appella, Daniel H

2017-05-22

Human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein 7 (NCp7), a zinc finger protein, plays critical roles in viral replication and maturation and is an attractive target for drug development. However, the development of drug-like molecules that inhibit NCp7 has been a significant challenge. In this study, a series of novel 2-mercaptobenzamide prodrugs were investigated for anti-HIV activity in the context of NCp7 inactivation. The molecules were synthesized from the corresponding thiosalicylic acids, and they are all crystalline solids and stable at room temperature. Derivatives with a range of amide side chains and aromatic substituents were synthesized and screened for anti-HIV activity. Wide ranges of antiviral activity were observed, with IC 50 values ranging from 1 to 100 μm depending on subtle changes to the substituents on the aromatic ring and side chain. Results from these structure-activity relationships were fit to a probable mode of intracellular activation and interaction with NCp7 to explain variations in antiviral activity. Our strategy to make a series of mercaptobenzamide prodrugs represents a general new direction to make libraries that can be screened for anti-HIV activity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Overlapping and Distinct Molecular Determinants Dictating the Antiviral Activities of TRIM56 against Flaviviruses and Coronavirus

PubMed Central

Liu, Baoming; Li, Nan L.; Wang, Jie; Shi, Pei-Yong; Wang, Tianyi; Miller, Mark A.

2014-01-01

ABSTRACT The tripartite motif-containing (TRIM) proteins have emerged as a new class of host antiviral restriction factors, with several demonstrating roles in regulating innate antiviral responses. Of >70 known TRIMs, TRIM56 inhibits replication of bovine viral diarrhea virus, a ruminant pestivirus of the family Flaviviridae, but has no appreciable effect on vesicular stomatitis virus (VSV), a rhabdovirus. Yet the antiviral spectrum of TRIM56 remains undefined. In particular, how TRIM56 impacts human-pathogenic viruses is unknown. Also unclear are the molecular determinants governing the antiviral activities of TRIM56. Herein, we show that TRIM56 poses a barrier to infections by yellow fever virus (YFV), dengue virus serotype 2 (DENV2), and human coronavirus virus (HCoV) OC43 but not encephalomyocarditis virus (EMCV). Moreover, by engineering cell lines conditionally expressing various TRIM56 mutants, we demonstrated that TRIM56's antiflavivirus effects required both the E3 ligase activity that lies in the N-terminal RING domain and the integrity of its C-terminal portion, while the restriction of HCoV-OC43 relied upon the TRIM56 E3 ligase activity alone. Furthermore, TRIM56 was revealed to impair YFV and DENV2 propagation by suppressing intracellular viral RNA accumulation but to compromise HCoV-OC43 infection at a later step in the viral life cycle, suggesting that distinct TRIM56 domains accommodate differing antiviral mechanisms. Altogether, TRIM56 is a versatile antiviral host factor that confers resistance to YFV, DENV2, and HCoV-OC43 through overlapping and distinct molecular determinants. IMPORTANCE We previously reported tripartite motif protein 56 (TRIM56) as a host restriction factor of bovine viral diarrhea virus, a ruminant pathogen. However, the impact of TRIM56 on human-pathogenic RNA viruses is unknown. Herein, we demonstrate that TRIM56 restricts two medically important flaviviruses, yellow fever virus (YFV) and dengue virus serotype 2 (DENV2), and a human coronavirus, HCoV-OC43, but not encephalomyocarditis virus, a picornavirus. Further, we show that TRIM56-mediated inhibition of HCoV-OC43 multiplication depends solely on its E3 ligase activity, whereas its restriction of YFV and DENV2 requires both the E3 ligase activity and integrity of the C-terminal portion. The differing molecular determinants appear to accommodate distinct antiviral mechanisms TRIM56 adopts to target different families of viruses; while TRIM56 curbs intracellular YFV/DENV2 RNA replication, it acts at a later step in HCoV-OC43 life cycle. These novel findings illuminate the molecular basis of the versatility and specificity of TRIM56's antiviral activities against positive-strand RNA viruses. PMID:25253338

Overlapping and distinct molecular determinants dictating the antiviral activities of TRIM56 against flaviviruses and coronavirus.

PubMed

Liu, Baoming; Li, Nan L; Wang, Jie; Shi, Pei-Yong; Wang, Tianyi; Miller, Mark A; Li, Kui

2014-12-01

The tripartite motif-containing (TRIM) proteins have emerged as a new class of host antiviral restriction factors, with several demonstrating roles in regulating innate antiviral responses. Of >70 known TRIMs, TRIM56 inhibits replication of bovine viral diarrhea virus, a ruminant pestivirus of the family Flaviviridae, but has no appreciable effect on vesicular stomatitis virus (VSV), a rhabdovirus. Yet the antiviral spectrum of TRIM56 remains undefined. In particular, how TRIM56 impacts human-pathogenic viruses is unknown. Also unclear are the molecular determinants governing the antiviral activities of TRIM56. Herein, we show that TRIM56 poses a barrier to infections by yellow fever virus (YFV), dengue virus serotype 2 (DENV2), and human coronavirus virus (HCoV) OC43 but not encephalomyocarditis virus (EMCV). Moreover, by engineering cell lines conditionally expressing various TRIM56 mutants, we demonstrated that TRIM56's antiflavivirus effects required both the E3 ligase activity that lies in the N-terminal RING domain and the integrity of its C-terminal portion, while the restriction of HCoV-OC43 relied upon the TRIM56 E3 ligase activity alone. Furthermore, TRIM56 was revealed to impair YFV and DENV2 propagation by suppressing intracellular viral RNA accumulation but to compromise HCoV-OC43 infection at a later step in the viral life cycle, suggesting that distinct TRIM56 domains accommodate differing antiviral mechanisms. Altogether, TRIM56 is a versatile antiviral host factor that confers resistance to YFV, DENV2, and HCoV-OC43 through overlapping and distinct molecular determinants. We previously reported tripartite motif protein 56 (TRIM56) as a host restriction factor of bovine viral diarrhea virus, a ruminant pathogen. However, the impact of TRIM56 on human-pathogenic RNA viruses is unknown. Herein, we demonstrate that TRIM56 restricts two medically important flaviviruses, yellow fever virus (YFV) and dengue virus serotype 2 (DENV2), and a human coronavirus, HCoV-OC43, but not encephalomyocarditis virus, a picornavirus. Further, we show that TRIM56-mediated inhibition of HCoV-OC43 multiplication depends solely on its E3 ligase activity, whereas its restriction of YFV and DENV2 requires both the E3 ligase activity and integrity of the C-terminal portion. The differing molecular determinants appear to accommodate distinct antiviral mechanisms TRIM56 adopts to target different families of viruses; while TRIM56 curbs intracellular YFV/DENV2 RNA replication, it acts at a later step in HCoV-OC43 life cycle. These novel findings illuminate the molecular basis of the versatility and specificity of TRIM56's antiviral activities against positive-strand RNA viruses. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

IFN regulatory factor 1 restricts hepatitis E virus replication by activating STAT1 to induce antiviral IFN-stimulated genes.

PubMed

Xu, Lei; Zhou, Xinying; Wang, Wenshi; Wang, Yijin; Yin, Yuebang; Laan, Luc J W van der; Sprengers, Dave; Metselaar, Herold J; Peppelenbosch, Maikel P; Pan, Qiuwei

2016-10-01

IFN regulatory factor 1 (IRF1) is one of the most important IFN-stimulated genes (ISGs) in cellular antiviral immunity. Although hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide, how ISGs counteract HEV infection is largely unknown. This study was conducted to investigate the effect of IRF1 on HEV replication. Multiple cell lines were used in 2 models that harbor HEV. In different HEV cell culture systems, IRF1 effectively inhibited HEV replication. IRF1 did not trigger IFN production, and chromatin immunoprecipitation sequencing data analysis revealed that IRF1 bound to the promoter region of signal transducers and activators of transcription 1 (STAT1). Functional assay confirmed that IRF1 could drive the transcription of STAT1, resulting in elevation of total and phosphorylated STAT1 proteins and further activating the transcription of a panel of downstream antiviral ISGs. By pharmacological inhibitors and RNAi-mediated gene-silencing approaches, we revealed that antiviral function of IRF1 is dependent on the JAK-STAT cascade. Furthermore, induction of ISGs and the anti-HEV effect of IRF1 overlapped that of IFNα, but was potentiated by ribavirin. We demonstrated that IRF1 effectively inhibits HEV replication through the activation of the JAK-STAT pathway, and the subsequent transcription of antiviral ISGs, but independent of IFN production.-Xu, L., Zhou, X., Wang, W., Wang, Y., Yin, Y., van der Laan, L. J. W., Sprengers, D., Metselaar, H. J., Peppelenbosch, M. P., Pan, Q. IFN regulatory factor 1 restricts hepatitis E virus replication by activating STAT1 to induce antiviral IFN-stimulated genes. © FASEB.

Discovery of potent broad spectrum antivirals derived from marine actinobacteria.

PubMed

Raveh, Avi; Delekta, Phillip C; Dobry, Craig J; Peng, Weiping; Schultz, Pamela J; Blakely, Pennelope K; Tai, Andrew W; Matainaho, Teatulohi; Irani, David N; Sherman, David H; Miller, David J

2013-01-01

Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable target for the continued development of broadly active antiviral compounds.

Discovery of Potent Broad Spectrum Antivirals Derived from Marine Actinobacteria

PubMed Central

Raveh, Avi; Delekta, Phillip C.; Dobry, Craig J.; Peng, Weiping; Schultz, Pamela J.; Blakely, Pennelope K.; Tai, Andrew W.; Matainaho, Teatulohi; Irani, David N.; Sherman, David H.; Miller, David J.

2013-01-01

Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable target for the continued development of broadly active antiviral compounds. PMID:24349254

Chemiluminescent activation of the antiviral activity of hypericin: a molecular flashlight.

PubMed Central

Carpenter, S; Fehr, M J; Kraus, G A; Petrich, J W

1994-01-01

Hypericin is a naturally occurring photosensitizer that displays potent antiviral activity in the presence of light. The absence of light in many regions of the body may preclude the use of hypericin and other photosensitizers as therapeutic compounds for the treatment of viral infections in vivo. The chemiluminescent oxidation of luciferin by the luciferase from the North American firefly Photinus pyralis was found to generate sufficiently intense and long-lived emission to induce antiviral activity of hypericin. Light-induced virucidal activity of hypericin was demonstrated against equine infectious anemia virus, a lentivirus structurally, genetically, and antigenically related to the human immunodeficiency virus. The implications for exploiting chemiluminescence as a "molecular flashlight" for effecting photodynamic therapy against virus-infected cells and tumor cells are discussed. PMID:7991618

Further evaluation of Rwandan medicinal plant extracts for their antimicrobial and antiviral activities.

PubMed

Cos, P; Hermans, N; De Bruyne, T; Apers, S; Sindambiwe, J B; Vanden Berghe, D; Pieters, L; Vlietinck, A J

2002-02-01

A total of 45 Rwandan plant extracts, belonging to 37 different plant species out of 21 families, were investigated for their antibacterial, antifungal, and antiviral properties. The plants were selected on the base of their ethnomedicinal use against infections and autoimmune diseases. From all the plant extracts tested, only Clematis hirsuta (leaves) showed a pronounced antifungal activity against Candida albicans and the dermatophytes Trichophyton rubrum, Epidermophyton floccosum, and Microsporum canis. Seven plant extracts showed a high antiviral activity against the DNA-virus Herpes simplex type 1, while five and three plant extracts were highly active against the RNA-viruses Coxsackie and Polio, respectively. Only Macaranga kilimandscharica (leaves) showed an interesting anti-measles activity, whereas Eriosema montanum (leaves) and Entada abyssinica (leaves) were highly active against Semliki forest virus. Some plant extracts showed an antibacterial activity against Gram-positive bacteria and Mycobacterium fortuitum, but none of them were active against the Gram-negative bacteria tested.

Influenza A Virus Dysregulates Host Histone Deacetylase 1 That Inhibits Viral Infection in Lung Epithelial Cells.

PubMed

Nagesh, Prashanth Thevkar; Husain, Matloob

2016-05-01

Viruses dysregulate the host factors that inhibit virus infection. Here, we demonstrate that human enzyme, histone deacetylase 1 (HDAC1) is a new class of host factor that inhibits influenza A virus (IAV) infection, and IAV dysregulates HDAC1 to efficiently replicate in epithelial cells. A time-dependent decrease in HDAC1 polypeptide level was observed in IAV-infected cells, reducing to <50% by 24 h of infection. A further depletion (97%) of HDAC1 expression by RNA interference increased the IAV growth kinetics, increasing it by >3-fold by 24 h and by >6-fold by 48 h of infection. Conversely, overexpression of HDAC1 decreased the IAV infection by >2-fold. Likewise, a time-dependent decrease in HDAC1 activity, albeit with slightly different kinetics to HDAC1 polypeptide reduction, was observed in infected cells. Nevertheless, a further inhibition of deacetylase activity increased IAV infection in a dose-dependent manner. HDAC1 is an important host deacetylase and, in addition to its role as a transcription repressor, HDAC1 has been lately described as a coactivator of type I interferon response. Consistent with this property, we found that inhibition of deacetylase activity either decreased or abolished the phosphorylation of signal transducer and activator of transcription I (STAT1) and expression of interferon-stimulated genes, IFITM3, ISG15, and viperin in IAV-infected cells. Furthermore, the knockdown of HDAC1 expression in infected cells decreased viperin expression by 58% and, conversely, the overexpression of HDAC1 increased it by 55%, indicating that HDAC1 is a component of IAV-induced host type I interferon antiviral response. Influenza A virus (IAV) continues to significantly impact global public health by causing regular seasonal epidemics, occasional pandemics, and zoonotic outbreaks. IAV is among the successful human viral pathogens that has evolved various strategies to evade host defenses, prevent the development of a universal vaccine, and acquire antiviral drug resistance. A comprehensive knowledge of IAV-host interactions is needed to develop a novel and alternative anti-IAV strategy. Host produces a variety of factors that are able to fight IAV infection by employing various mechanisms. However, the full repertoire of anti-IAV host factors and their antiviral mechanisms has yet to be identified. We have identified here a new host factor, histone deacetylase 1 (HDAC1) that inhibits IAV infection. We demonstrate that HDAC1 is a component of host innate antiviral response against IAV, and IAV undermines HDAC1 to limit its role in antiviral response. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

TRIM25 in the Regulation of the Antiviral Innate Immunity

PubMed Central

Martín-Vicente, María; Medrano, Luz M.; Resino, Salvador; García-Sastre, Adolfo; Martínez, Isidoro

2017-01-01

TRIM25 is an E3 ubiquitin ligase enzyme that is involved in various cellular processes, including regulation of the innate immune response against viruses. TRIM25-mediated ubiquitination of the cytosolic pattern recognition receptor RIG-I is an essential step for initiation of the intracellular antiviral response and has been thoroughly documented. In recent years, however, additional roles of TRIM25 in early innate immunity are emerging, including negative regulation of RIG-I, activation of the melanoma differentiation-associated protein 5–mitochondrial antiviral signaling protein–TRAF6 antiviral axis and modulation of p53 levels and activity. In addition, the ability of TRIM25 to bind RNA may uncover new mechanisms by which this molecule regulates intracellular signaling and/or RNA virus replication. PMID:29018447

Which Plant Proteins Are Involved in Antiviral Defense? Review on In Vivo and In Vitro Activities of Selected Plant Proteins against Viruses.

PubMed

Musidlak, Oskar; Nawrot, Robert; Goździcka-Józefiak, Anna

2017-11-01

Plants have evolved a variety of defense mechanisms to tackle virus attack. Endogenous plant proteins can function as virus suppressors. Different types of proteins mediate defense responses against plant viruses. Pathogenesis-related (PR) proteins are activated upon pathogen infections or in different stress situations and their production is one of many components in plant defense. Ribosome-inactivating proteins (RIPs) suppress translation by enzymatically damaging ribosomes and they have been found to have antiviral activity. RNA-binding proteins (RBPs) bind to target RNAs via specialized RNA-binding domain and can directly or indirectly function in plant defense system against RNA viruses. Proteins involved in silencing machinery, namely Dicer-like (DCL) proteins, Argonaute (AGO) proteins, and RNA-dependent RNA polymerases (RDRs) confer innate antiviral defense in plants as they are able to degrade foreign RNA of viral origin. This review aims to provide a comprehensive and up-to-date picture of plant proteins participating in antiviral defense. As a result we discuss proteins conferring plant antiviral resistance and their potential future applications in different fields of life including agriculture and medicine.

Which Plant Proteins Are Involved in Antiviral Defense? Review on In Vivo and In Vitro Activities of Selected Plant Proteins against Viruses

PubMed Central

Goździcka-Józefiak, Anna

2017-01-01

Plants have evolved a variety of defense mechanisms to tackle virus attack. Endogenous plant proteins can function as virus suppressors. Different types of proteins mediate defense responses against plant viruses. Pathogenesis-related (PR) proteins are activated upon pathogen infections or in different stress situations and their production is one of many components in plant defense. Ribosome-inactivating proteins (RIPs) suppress translation by enzymatically damaging ribosomes and they have been found to have antiviral activity. RNA-binding proteins (RBPs) bind to target RNAs via specialized RNA-binding domain and can directly or indirectly function in plant defense system against RNA viruses. Proteins involved in silencing machinery, namely Dicer-like (DCL) proteins, Argonaute (AGO) proteins, and RNA-dependent RNA polymerases (RDRs) confer innate antiviral defense in plants as they are able to degrade foreign RNA of viral origin. This review aims to provide a comprehensive and up-to-date picture of plant proteins participating in antiviral defense. As a result we discuss proteins conferring plant antiviral resistance and their potential future applications in different fields of life including agriculture and medicine. PMID:29104238

Application of electrolysis for inactivation of an antiviral drug that is one of possible selection pressure to drug-resistant influenza viruses.

PubMed

Kobayashi, Toyohide; Hirose, Jun; Wu, Hong; Sano, Kouichi; Katsumata, Takahiro; Tsujibo, Hiroshi; Nakano, Takashi

2013-12-01

The recent development of antiviral drugs has led to concern that the release of the chemicals in surface water due to expanded medical use could induce drug-resistant mutant viruses in zoonosis. Many researchers have noted that the appearance of an oseltamivir (Tamiflu(®))-resistant avian influenza mutant virus, which may spread to humans, could be induced by oseltamivir contamination of surface water. Although past studies have reported electrolysis as a possible method for degradation of antineoplastics and antibacterials in water, the validity of the method for treatment of antiviral drugs is unknown. In this study, electrolysis was used to degrade an antiviral prodrug, oseltamivir, and a stable active form, oseltamivir carboxylate, and the degradation process was monitored with HPLC-UV and the neuraminidase inhibitory assay. HPLC-UV-detectable oseltamivir and oseltamivir carboxylate were decomposed by electrolysis within 60 min, and inhibitory activity of neuraminidase decreased below the detection limit of the assay used. Cytotoxic and genotoxic activity were not detected in electrolyzed fluid. These results indicate that electrolysis is a possible treatment for inactivation of the antiviral drug oseltamivir. Copyright © 2013 Elsevier B.V. All rights reserved.

In-vitro antiviral efficacy of ribavirin and interferon-alpha against canine distemper virus.

PubMed

Carvalho, Otávio V; Saraiva, Giuliana L; Ferreira, Caroline G T; Felix, Daniele M; Fietto, Juliana L R; Bressan, Gustavo C; Almeida, Márcia R; Silva Júnior, Abelardo

2014-10-01

Canine distemper is a highly contagious disease with high incidence and lethality in the canine population. The objective of this study was to evaluate the efficacy of antiviral action with ribavirin (RBV), interferon-alpha (IFNα), and combinations of RBV and IFNα against canine distemper virus (CDV). Vero cells inoculated with CDV were treated with RBV, IFNα, and combinations of these drugs. The efficacy to inhibit viral replication was evaluated by adding the compounds at different times to determine which step of the viral replicative process was affected. Both drugs were effective against CDV in vitro. The IFNα was the most active compound, with an average IC50 (50% inhibitory concentration) value lower than the IC50 of the RBV. Ribavirin (RBV) was more selective than IFNα, however, and neither drug showed extracellular antiviral activity. The combination of RBV and IFNα exhibited antiviral activity for the intra- and extracellular stages of the replicative cycle of CDV, although the intracellular viral inhibition was higher. Both RBV and IFNα showed high antiviral efficacy against CDV, and furthermore, RBV + IFNα combinations have shown greater interference range in viral infectivity. These compounds could potentially be used to treat clinical disease associated with CDV infection.

In-vitro antiviral efficacy of ribavirin and interferon-alpha against canine distemper virus

PubMed Central

Carvalho, Otávio V.; Saraiva, Giuliana L.; Ferreira, Caroline G.T.; Felix, Daniele M.; Fietto, Juliana L.R.; Bressan, Gustavo C.; Almeida, Márcia R.; Silva Júnior, Abelardo

2014-01-01

Canine distemper is a highly contagious disease with high incidence and lethality in the canine population. The objective of this study was to evaluate the efficacy of antiviral action with ribavirin (RBV), interferon-alpha (IFNα), and combinations of RBV and IFNα against canine distemper virus (CDV). Vero cells inoculated with CDV were treated with RBV, IFNα, and combinations of these drugs. The efficacy to inhibit viral replication was evaluated by adding the compounds at different times to determine which step of the viral replicative process was affected. Both drugs were effective against CDV in vitro. The IFNα was the most active compound, with an average IC50 (50% inhibitory concentration) value lower than the IC50 of the RBV. Ribavirin (RBV) was more selective than IFNα, however, and neither drug showed extracellular antiviral activity. The combination of RBV and IFNα exhibited antiviral activity for the intra- and extracellular stages of the replicative cycle of CDV, although the intracellular viral inhibition was higher. Both RBV and IFNα showed high antiviral efficacy against CDV, and furthermore, RBV + IFNα combinations have shown greater interference range in viral infectivity. These compounds could potentially be used to treat clinical disease associated with CDV infection. PMID:25355997

Research in drug development against viral diseases of military importance (biological testing). Volume 1. Final report, 15 November 1985-31 January 1991

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

Shannon, W.M.; Arnett, G.; Brazier, A.D.

1991-03-01

The purpose of this program is to evaluate the efficacy of candidate antiviral compounds against a spectrum of viruses of military importance. This program involves (a) primary testing of chemical compounds and natural products for antiviral efficacy in vitro using standard CPE-inhibition assays, (b) primary testing of compounds for antiviral efficacy in vivo in animal model systems, and (c) secondary evaluation of the active candidate antiviral compounds. The target viruses for in vitro testing are Vaccinia Virus (VV), Adenovirus (AD2), Vesicular Stomatitis Virus (VSV), Punta Toro Virus (PT), Sandfly Fever Virus (SF), Yellow Fever Virus (YF), Venezuelan Equine Encephalomyelitis Virusmore » (VE), Japanese Encephalitis Virus and Vaccinia Virus infections of mice. Approximately 10,000 compounds have been received for in vitro evaluation and over 66,000 assays have been performed on this contract. Compounds have been identified in nearly all virus systems that have confirmed antiviral activity equal or exceeding that of the various positive control compounds (Ribavirin, Selenazofurin, Carbocyclic-3-deaza-adenosine, Adenosine dialdehyde, Ara-A, ddC and AZT). Many of these compounds represent potent and selective new antiviral agents.« less

Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses.

PubMed

Nácher-Vázquez, Montserrat; Ballesteros, Natalia; Canales, Ángeles; Rodríguez Saint-Jean, Sylvia; Pérez-Prieto, Sara Isabel; Prieto, Alicia; Aznar, Rosa; López, Paloma

2015-06-25

Viral infections in the aquaculture of salmonids can lead to high mortality and substantial economic losses. Thus, there is industrial interest in new molecules active against these viruses. Here we describe the production, purification, and the physicochemical and structural characterization of high molecular weight dextrans synthesized by Lactobacillus sakei MN1 and Leuconostoc mesenteroides RTF10. The purified dextrans, and commercial dextrans with molecular weights ranging from 10 to 2000kDa, were assayed in infected BF-2 and EPC fish cell-line monolayers for antiviral activity. Only T2000 and dextrans from MN1 and RTF10 had significant antiviral activity. This was similar to results obtained against infectious pancreatic necrosis virus. However the dextran from MN1 showed ten-fold higher activity against hematopoietic necrosis virus than T2000. In vivo assays using the MN1 polymer confirmed the in vitro results and revealed immunomodulatory activity. These results together with the high levels of dextran production (2gL(-1)) by Lb. sakei MN1, indicate the compounds potential utility as an antiviral agent in aquaculture. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Nucleocapsid Protein of Coronaviruses Acts as a Viral Suppressor of RNA Silencing in Mammalian Cells.

PubMed

Cui, Lei; Wang, Haiying; Ji, Yanxi; Yang, Jie; Xu, Shan; Huang, Xingyu; Wang, Zidao; Qin, Lei; Tien, Po; Zhou, Xi; Guo, Deyin; Chen, Yu

2015-09-01

RNA interference (RNAi) is a process of eukaryotic posttranscriptional gene silencing that functions in antiviral immunity in plants, nematodes, and insects. However, recent studies provided strong supports that RNAi also plays a role in antiviral mechanism in mammalian cells. To combat RNAi-mediated antiviral responses, many viruses encode viral suppressors of RNA silencing (VSR) to facilitate their replication. VSRs have been widely studied for plant and insect viruses, but only a few have been defined for mammalian viruses currently. We identified a novel VSR from coronaviruses, a group of medically important mammalian viruses including Severe acute respiratory syndrome coronavirus (SARS-CoV), and showed that the nucleocapsid protein (N protein) of coronaviruses suppresses RNAi triggered by either short hairpin RNAs or small interfering RNAs in mammalian cells. Mouse hepatitis virus (MHV) is closely related to SARS-CoV in the family Coronaviridae and was used as a coronavirus replication model. The replication of MHV increased when the N proteins were expressed in trans, while knockdown of Dicer1 or Ago2 transcripts facilitated the MHV replication in mammalian cells. These results support the hypothesis that RNAi is a part of the antiviral immunity responses in mammalian cells. IMPORTANCE RNAi has been well known to play important antiviral roles from plants to invertebrates. However, recent studies provided strong supports that RNAi is also involved in antiviral response in mammalian cells. An important indication for RNAi-mediated antiviral activity in mammals is the fact that a number of mammalian viruses encode potent suppressors of RNA silencing. Our results demonstrate that coronavirus N protein could function as a VSR through its double-stranded RNA binding activity. Mutational analysis of N protein allowed us to find out the critical residues for the VSR activity. Using the MHV-A59 as the coronavirus replication model, we showed that ectopic expression of SARS-CoV N protein could promote MHV replication in RNAi-active cells but not in RNAi-depleted cells. These results indicate that coronaviruses encode a VSR that functions in the replication cycle and provide further evidence to support that RNAi-mediated antiviral response exists in mammalian cells.

Niclosamide is a proton carrier and targets acidic endosomes with broad antiviral effects.

PubMed

Jurgeit, Andreas; McDowell, Robert; Moese, Stefan; Meldrum, Eric; Schwendener, Reto; Greber, Urs F

2012-01-01

Viruses use a limited set of host pathways for infection. These pathways represent bona fide antiviral targets with low likelihood of viral resistance. We identified the salicylanilide niclosamide as a broad range antiviral agent targeting acidified endosomes. Niclosamide is approved for human use against helminthic infections, and has anti-neoplastic and antiviral effects. Its mode of action is unknown. Here, we show that niclosamide, which is a weak lipophilic acid inhibited infection with pH-dependent human rhinoviruses (HRV) and influenza virus. Structure-activity studies showed that antiviral efficacy and endolysosomal pH neutralization co-tracked, and acidification of the extracellular medium bypassed the virus entry block. Niclosamide did not affect the vacuolar H(+)-ATPase, but neutralized coated vesicles or synthetic liposomes, indicating a proton carrier mode-of-action independent of any protein target. This report demonstrates that physico-chemical interference with host pathways has broad range antiviral effects, and provides a proof of concept for the development of host-directed antivirals.

Comparison of the Antiviral Effects of 5-Methoxymethyl-deoxyuridine with 5-Iododeoxyuridine, Cytosine Arabinoside, and Adenine Arabinoside

PubMed Central

Babiuk, Lorne A.; Meldrum, Blair; Gupta, V. Sagar; Rouse, Barry T.

1975-01-01

The antiviral activity of 5-methoxymethyl-2′-deoxyuridine (MMUdR) was compared with that of 5-iodo-2′-deoxyuridine (IUdR), cytosine arabinoside (Ara-C), and adenine arabinoside (Ara-A). At concentrations of 2 to 4 μg/ml, MMUdR was inhibitory to herpes simplex virus type 1, but concentrations as high as 128 μg/ml were not inhibitory to three other herpesviruses tested (equine rhinopneumonitis virus, murine cytomegalovirus, and feline rhinopneumonitis virus) or to vaccinia virus. The other nucleosides, in contrast, were inhibitory at similar concentrations (1 to 8 μg/ml) against all viruses tested. The inhibition of HSV-1 by MMUdR appeared to be the result of interference with virus replication rather than the result of drug toxicity to host cells. The drug was not toxic to host cells at 100 times the antiviral concentrations, and pretreatment of host cells with high concentrations of MMUdR had no effect on subsequent virus replication. Combination of MMUdR with either IUdR, Ara-A, or Ara-C gave an enhanced antiviral effect, suggesting that the mechanism of action of MMUdR is different from that of the other three drugs. Antiviral indexes were calculated for each compound and were found to be >250, 80, 40, and 8 for MMUdR, IUdR, Ara-A, and Ara-C, respectively. These were defined as the minimum dose at which toxicity was observed microscopically divided by the dose which reduced plaque numbers by 50%. PMID:1239978

Antiviral Activity of Nordihydroguaiaretic Acid and Its Derivative Tetra-O-Methyl Nordihydroguaiaretic Acid against West Nile Virus and Zika Virus.

PubMed

Merino-Ramos, Teresa; Jiménez de Oya, Nereida; Saiz, Juan-Carlos; Martín-Acebes, Miguel A

2017-08-01

Flaviviruses are positive-strand RNA viruses distributed all over the world that infect millions of people every year and for which no specific antiviral agents have been approved. These viruses include the mosquito-borne West Nile virus (WNV), which is responsible for outbreaks of meningitis and encephalitis. Considering that nordihydroguaiaretic acid (NDGA) has been previously shown to inhibit the multiplication of the related dengue virus and hepatitis C virus, we have evaluated the effect of NDGA, and its methylated derivative tetra- O -methyl nordihydroguaiaretic acid (M 4 N), on the infection of WNV. Both compounds inhibited the infection of WNV, likely by impairing viral replication. Since flavivirus multiplication is highly dependent on host cell lipid metabolism, the antiviral effect of NDGA has been previously related to its ability to disturb the lipid metabolism, probably by interfering with the sterol regulatory element-binding proteins (SREBP) pathway. Remarkably, we observed that other structurally unrelated inhibitors of the SREBP pathway, such as PF-429242 and fatostatin, also reduced WNV multiplication, supporting that the SREBP pathway may constitute a druggable target suitable for antiviral intervention against flavivirus infection. Moreover, treatment with NDGA, M 4 N, PF-429242, and fatostatin also inhibited the multiplication of the mosquito-borne flavivirus Zika virus (ZIKV), which has been recently associated with birth defects (microcephaly) and neurological disorders. Our results point to SREBP inhibitors, such as NDGA and M 4 N, as potential candidates for further antiviral development against medically relevant flaviviruses. Copyright © 2017 American Society for Microbiology.

Antiviral activity of some Tunisian medicinal plants against Herpes simplex virus type 1.

PubMed

Sassi, A Ben; Harzallah-Skhiri, F; Bourgougnon, N; Aouni, M

2008-01-10

Fifteen species of Tunisian traditional medicinal plants, belonging to 10 families, were selected for this study. They were Inula viscosa (L.) Ait and Reichardia tingitana (L.) Roth ssp. discolor (Pom.) Batt. (Asteraceae), Mesembryanthemum cristallinum L. and M. nodiflorum L. (Aizoaceae), Arthrocnemum indicum (Willd.) Moq., Atriplex inflata Muell., A. parvifolia Lowe var. ifiniensis (Caball) Maire, and Salicornia fruticosa L. (Chenopodiaceae), Cistus monspeliensis L. (Cistaceae), Juniperus phoenicea L. (Cupressaceae), Erica multiflora L. (Ericaceae), Frankenia pulverulenta L. (Frankeniaceae), Hypericum crispum L. (Hypericaceae), Plantago coronopus L. ssp. eu-coronopus Pilger var. vulgaris G.G. (Plantaginaceae) and Zygophyllum album L. (Zygophyllaceae). Fifty extracts prepared from those plants were screened in order to assay their antiviral activity against Herpes simplex virus type 1 (HSV-1), using neutral red incorporation. Extracts from eight plants among these 15 showed some degree of antiviral activity, while the methanolic extract of E. multiflora was highly active with EC(50) of 132.6 microg mL(-1). These results corroborate that medicinal plants from Tunisia can be a rich source of potential antiviral compounds.

Mechanism of TRIM25 Catalytic Activation in the Antiviral RIG-I Pathway.

PubMed

Sanchez, Jacint G; Chiang, Jessica J; Sparrer, Konstantin M J; Alam, Steven L; Chi, Michael; Roganowicz, Marcin D; Sankaran, Banumathi; Gack, Michaela U; Pornillos, Owen

2016-08-02

Antiviral response pathways induce interferon by higher-order assembly of signaling complexes called signalosomes. Assembly of the RIG-I signalosome is regulated by K63-linked polyubiquitin chains, which are synthesized by the E3 ubiquitin ligase, TRIM25. We have previously shown that the TRIM25 coiled-coil domain is a stable, antiparallel dimer that positions two catalytic RING domains on opposite ends of an elongated rod. We now show that the RING domain is a separate self-association motif that engages ubiquitin-conjugated E2 enzymes as a dimer. RING dimerization is required for catalysis, TRIM25-mediated RIG-I ubiquitination, interferon induction, and antiviral activity. We also provide evidence that RING dimerization and E3 ligase activity are promoted by binding of the TRIM25 SPRY domain to the RIG-I effector domain. These results indicate that TRIM25 actively participates in higher-order assembly of the RIG-I signalosome and helps to fine-tune the efficiency of the RIG-I-mediated antiviral response. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Mechanism of TRIM25 Catalytic Activation in the Antiviral RIG-I Pathway

DOE PAGES

Sanchez, Jacint G.; Chiang, Jessica J.; Sparrer, Konstantin M. J.; ...

2016-07-14

Antiviral response pathways induce interferon by higher-order assembly of signaling complexes called signalosomes. Assembly of the RIG-I signalosome is regulated by K63-linked polyubiquitin chains, which are synthesized by the E3 ubiquitin ligase, TRIM25. We have previously shown that the TRIM25 coiled-coil domain is a stable, antiparallel dimer that positions two catalytic RING domains on opposite ends of an elongated rod. We now show that the RING domain is a separate self-association motif that engages ubiquitin-conjugated E2 enzymes as a dimer. RING dimerization is required for catalysis, TRIM25-mediated RIG-I ubiquitination, interferon induction, and antiviral activity. We also provide evidence that RINGmore » dimerization and E3 ligase activity are promoted by binding of the TRIM25 SPRY domain to the RIG-I effector domain. These results indicate that TRIM25 actively participates in higher-order assembly of the RIG-I signalosome and helps to fine-tune the efficiency of the RIG-I-mediated antiviral response.« less

Identification of Inonotus obliquus polysaccharide with broad-spectrum antiviral activity against multi-feline viruses.

PubMed

Tian, Jin; Hu, Xiaoliang; Liu, Dafei; Wu, Hongxia; Qu, Liandong

2017-02-01

Inonotus obliquus polysaccharides (IOPs) are a potential drug for the prevention and treatment of cancer, cardiopathy, diabetes, AIDs, pancreatitis and other diseases. In this study, we found that IOP can act as a broad-spectrum antiviral drug against feline viruses in the in vitro experiment. Using cell models of feline calicivirus (FCV), we demonstrated that IOP treatment was capable of exhibiting anti-FCV strain F9 activity in cell-based assays and also showed low cytotoxicity. Investigation of the mechanism of action of the compound revealed that IOP treatment induces its inhibitory actions directly on virus particles through blocking viral binding/absorpting. The inhibitory activity against other FCV isolates from China was also identified. More importantly, we found that IOP exhibited broad-spectrum antiviral activity against the feline herpesvirus 1, feline influenza virus H3N2 and H5N6, feline panleukopenia virus and feline infectious peritonitis virus that can contribute to respiratory and gastrointestinal diseases in cats. These findings suggest that IOP may be a potential broad-spectrum antiviral drug against feline viruses. Copyright © 2016 Elsevier B.V. All rights reserved.

Tuberculosis in HIV-infected patients in Croatia between 1986 and 2005.

PubMed

Puljiz, Ivan; Begovac, Josip

2006-12-01

A retrospective medical chart review was performed on 65 HIV-infected patients with tuberculosis hospitalized between 1986 and 2006 at the University Hospital for Infectious Diseases "Dr. Fran Mihaljević", Zagreb. Thirty two patients presented with pulmonary involvement, 13 with extrapulmonary, and 20 patients had disseminated tuberculosis. Forty five patients had an abnormal chest X-ray. Mycobacterium tuberculosis was identified in 35 (53.9%) patients. Ten (15.3%) of 65 patients had already been receiving antiviral therapy, while another 31 (47.7%) initiated antiviral therapy after antituberculosis therapy. Tuberculosis-associated immune reconstitution inflammatory syndrome was observed in 11/27 (40.7%) patients. Forty one patient received the standard six month course of antituberculous therapy, while in 12 patients the therapy was prolonged. Twenty one patient (32%) experienced an adverse event to antituberculosis drugs. Twelve patients died (18.5%). After the introduction of highly active antiviral therapy (HAART) the mortality decreased. The incidence of tuberculosis in HIV-infected patients in Croatia is increasing, and tuberculosis is still an important opportunistic infection in our HIV-infected patients.

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

Ghosh, Arun K.; Takayama, Jun; Rao, Kalapala Venkateswar

The design, synthesis, X-ray crystal structure, molecular modeling, and biological evaluation of a series of new generation SARS-CoV PLpro inhibitors are described. A new lead compound 3 (6577871) was identified via high-throughput screening of a diverse chemical library. Subsequently, we carried out lead optimization and structure-activity studies to provide a series of improved inhibitors that show potent PLpro inhibition and antiviral activity against SARS-CoV infected Vero E6 cells. Interestingly, the (S)-Me inhibitor 15h (enzyme IC{sub 50} = 0.56 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) and the corresponding (R)-Me 15g (IC{sub 50} = 0.32 {mu}M; antiviral EC{sub 50} = 9.1more » {mu}M) are the most potent compounds in this series, with nearly equivalent enzymatic inhibition and antiviral activity. A protein-ligand X-ray structure of 15g-bound SARS-CoV PLpro and a corresponding model of 15h docked to PLpro provide intriguing molecular insight into the ligand-binding site interactions.« less

Identification of five interferon-induced cellular proteins that inhibit west nile virus and dengue virus infections.

PubMed

Jiang, Dong; Weidner, Jessica M; Qing, Min; Pan, Xiao-Ben; Guo, Haitao; Xu, Chunxiao; Zhang, Xianchao; Birk, Alex; Chang, Jinhong; Shi, Pei-Yong; Block, Timothy M; Guo, Ju-Tao

2010-08-01

Interferons (IFNs) are key mediators of the host innate antiviral immune response. To identify IFN-stimulated genes (ISGs) that instigate an antiviral state against two medically important flaviviruses, West Nile virus (WNV) and dengue virus (DENV), we tested 36 ISGs that are commonly induced by IFN-alpha for antiviral activity against the two viruses. We discovered that five ISGs efficiently suppressed WNV and/or DENV infection when they were individually expressed in HEK293 cells. Mechanistic analyses revealed that two structurally related cell plasma membrane proteins, IFITM2 and IFITM3, disrupted early steps (entry and/or uncoating) of the viral infection. In contrast, three IFN-induced cellular enzymes, viperin, ISG20, and double-stranded-RNA-activated protein kinase, inhibited steps in viral proteins and/or RNA biosynthesis. Our results thus imply that the antiviral activity of IFN-alpha is collectively mediated by a panel of ISGs that disrupt multiple steps of the DENV and WNV life cycles.

Virocidal activity of Egyptian scorpion venoms against hepatitis C virus.

PubMed

El-Bitar, Alaa M H; Sarhan, Moustafa M H; Aoki, Chie; Takahara, Yusuke; Komoto, Mari; Deng, Lin; Moustafa, Mohsen A; Hotta, Hak

2015-03-24

Hepatitis C virus (HCV) is a major global health problem, causing chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Development of well-tolerated regimens with high cure rates and fewer side effects is still much needed. Recently, natural antimicrobial peptides (AMPs) are attracting more attention as biological compounds and can be a good template to develop therapeutic agents, including antiviral agents against a variety of viruses. Various AMPs have been characterized from the venom of different venomous animals including scorpions. The possible antiviral activities of crude venoms obtained from five Egyptian scorpion species (Leiurus quinquestriatus, Androctonus amoreuxi, A. australis, A. bicolor and Scorpio maurus palmatus) were evaluated by a cell culture method using Huh7.5 cells and the J6/JFH1-P47 strain of HCV. Time-of-addition experiments and inactivation of enzymatic activities of the venoms were carried out to determine the characteristics of the anti-HCV activities. S. maurus palmatus and A. australis venoms showed anti-HCV activities, with 50% inhibitory concentrations (IC₅₀) being 6.3 ± 1.6 and 88.3 ± 5.8 μg/ml, respectively. S. maurus palmatus venom (30 μg/ml) impaired HCV infectivity in culture medium, but not inside the cells, through virocidal effect. The anti-HCV activity of this venom was not inhibited by a metalloprotease inhibitor or heating at 60°C. The antiviral activity was directed preferentially against HCV. S. maurus palmatus venom is considered as a good natural source for characterization and development of novel anti-HCV agents targeting the entry step. To our knowledge, this is the first report describing antiviral activities of Egyptian scorpion venoms against HCV, and may open a new approach towards discovering antiviral compounds derived from scorpion venoms.

Interaction of humic acids and humic-acid-like polymers with herpes simplex virus type 1

NASA Astrophysics Data System (ADS)

Klöcking, Renate; Helbig, Björn

The study was performed in order to compare the antiviral activity against herpes simplex virus type 1 (HSV-1) of synthetic humic-acid-like polymers to that of their low-molecular-weight basic compounds and naturally occurring humic acids (HA) in vitro. HA from peat water showed a moderate antiviral activity at a minimum effective concentration (MEC) of 20 µg/ml. HA-like polymers, i.e. the oxidation products of caffeic acid (KOP), hydrocaffeic acid (HYKOP), chlorogenic acid (CHOP), 3,4-dihydroxyphenylacetic acid (3,4-DHPOP), nordihydroguaretic acid (NOROP), gentisinic acid (GENOP), pyrogallol (PYROP) and gallic acid (GALOP), generally inhibit virus multiplication, although with different potency and selectivity. Of the substances tested, GENOP, KOP, 3,4-DHPOP and HYKOP with MEC values in the range of 2 to 10 µg/ml, proved to be the most potent HSV-1 inhibitors. Despite its lower antiviral potency (MEC 40 µg/ml), CHOP has a remarkable selectivity due to the high concentration of this polymer that is tolerated by the host cells (>640 µg/ml). As a rule, the antiviral activity of the synthetic compounds was restricted to the polymers and was not preformed in the low-molecular-weight basic compounds. This finding speaks in favour of the formation of antivirally active structures during the oxidative polymerization of phenolic compounds and, indirectly, of corresponding structural parts in different HA-type substances.

Antiviral activity of exopolysaccharides from Arthrospira platensis against koi herpesvirus.

PubMed

Reichert, M; Bergmann, S M; Hwang, J; Buchholz, R; Lindenberger, C

2017-10-01

Although koi herpesvirus (KHV) has a history of causing severe economic losses in common carp and koi farms, there are still no treatments available on the market. Thus, the aim of this study was to test exopolysaccharides (EPS) for its antiviral activity against KHV, by monitoring inhibition and cytotoxic effects in common carp brain cells. These substances can be easily extracted from extracellular algae supernatant and were identified as groups of sulphated polysaccharides. In order to reach this aim, Arthrospira platensis, which is well known for its antiviral activity of intra- and extracellular compounds towards mammalian herpesviruses, was investigated as standard organism and compared to commercial antiviral drug, ganciclovir, which inhibits the viral DNA polymerization. The antiviral activity of polysaccharides of A. platensis against KHV was confirmed in vitro using qualitative assessment of KHV life cycle genes, and it was found by RT-PCR that EPS, applied at a concentration of >18 μg mL -1 and a multiplicity of infection (MOI) of 0.45 of KHV, suppressed the viral replication in common carp brain (CCB) cells even after 22 days post-infection, entirely. Further, this study presents first data indicating an enormous potential using polysaccharides as an additive for aquacultures to lower or hinder the spread of the KHV and koi herpesvirus disease (KHVD) in future. © 2017 John Wiley & Sons Ltd.

Activation of innate antiviral immune response via double-stranded RNA-dependent RLR receptor-mediated necroptosis

PubMed Central

Wang, Wei; Wang, Wei-Hua; Azadzoi, Kazem M.; Su, Ning; Dai, Peng; Sun, Jianbin; Wang, Qin; Liang, Ping; Zhang, Wentao; Lei, Xiaoying; Yan, Zhen; Yang, Jing-Hua

2016-01-01

Viruses induce double-stranded RNA (dsRNA) in the host cells. The mammalian system has developed dsRNA-dependent recognition receptors such as RLRs that recognize the long stretches of dsRNA as PAMPs to activate interferon-mediated antiviral pathways and apoptosis in severe infection. Here we report an efficient antiviral immune response through dsRNA-dependent RLR receptor-mediated necroptosis against infections from different classes of viruses. We demonstrated that virus-infected A549 cells were efficiently killed in the presence of a chimeric RLR receptor, dsCARE. It measurably suppressed the interferon antiviral pathway but promoted IL-1β production. Canonical cell death analysis by morphologic assessment, phosphatidylserine exposure, caspase cleavage and chemical inhibition excluded the involvement of apoptosis and consistently suggested RLR receptor-mediated necroptosis as the underlying mechanism of infected cell death. The necroptotic pathway was augmented by the formation of RIP1-RIP3 necrosome, recruitment of MLKL protein and the activation of cathepsin D. Contributing roles of RIP1 and RIP3 were confirmed by gene knockdown. Furthermore, the necroptosis inhibitor necrostatin-1 but not the pan-caspase inhibitor zVAD impeded dsCARE-dependent infected cell death. Our data provides compelling evidence that the chimeric RLR receptor shifts the common interferon antiviral responses of infected cells to necroptosis and leads to rapid death of the virus-infected cells. This mechanism could be targeted as an efficient antiviral strategy. PMID:26935990

The antimalarial drug amodiaquine possesses anti-ZIKA virus activities.

PubMed

Han, Yingshan; Mesplède, Thibault; Xu, Hongtao; Quan, Yudong; Wainberg, Mark A

2018-05-01

Zika virus (ZIKV) outbreak has emerged as a global health threat, particularly in tropical areas, over the past few years. No antiviral therapy or vaccine is available at present. For these reasons, repurposing clinically approved drugs against ZIKV infection may provide rapid and cost-effective global health benefits. Here, we explored this strategy and screened eight FDA-approved drugs for antiviral activity against ZIKV using a cell-based assay. Our results show that the antimalarial drug amodiaquine has anti-ZIKV activity with EC 50 at low micromolar concentrations in cell culture. We further characterized amodiaquine antiviral activity against ZIKV and found that it targets early events of the viral replication cycle. Altogether, our results suggest that amodiaquine may be efficacious for the treatment of ZIKV infection. © 2018 Wiley Periodicals, Inc.

Linear and branched alkyl-esters and amides of gallic acid and other (mono-, di- and tri-) hydroxy benzoyl derivatives as promising anti-HCV inhibitors.

PubMed

Rivero-Buceta, Eva; Carrero, Paula; Doyagüez, Elisa G; Madrona, Andrés; Quesada, Ernesto; Camarasa, María José; Peréz-Pérez, María Jesús; Leyssen, Pieter; Paeshuyse, Jan; Balzarini, Jan; Neyts, Johan; San-Félix, Ana

2015-03-06

Linear and branched compounds that contain two, three or five units of galloyl (3,4,5-trihydroxybenzoyl) or its isomer 2,3,4-trihydroxybenzoyl, as well as other mono- or dihydroxybenzoyl moieties have been synthesized. These molecules have been evaluated for their in vitro inhibitory effects against a wide panel of viruses showing preferential activity against HIV and HCV. Our structure-activity relationship studies demonstrated that the 2,3,4-trihydroxybenzoyl moiety provides better antiviral activities than the galloyl (3,4,5-trihydroxybenzoyl) moiety that is present in natural green tea catechins. This observation can be of interest for the further rational exploration of compounds with anti-HCV/HIV properties. The most notable finding with respect to HIV is that the tripodal compounds 43 and 45, with three 2,3,4-trihydroxybenzoyl moieties, showed higher activities than linear compounds with only one or two. With respect to HCV, the linear compounds, 52 and 41, containing a 12 polymethylene chain and two 2,3 di- or 2,3,4 tri-hydroxybenzoyl groups respectively at the ends of the molecule showed good antiviral efficiency. Furthermore, the anti-HCV activity of both compounds was observed at concentrations well below the cytotoxicity threshold. A representative member of these compounds, 41, showed that the anti-HCV activity was largely independent of the genetic make-up of the HCV subgenomic replicon and cell lines used. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

[Adenovirus-mediated canine interferon-gamma expression and its antiviral activity against canine parvovirus].

PubMed

Zhang, Kao; Jin, Huijun; Zhong, Fei; Li, Xiujin; Neng, Changai; Chen, Huihui; Li, Wenyan; Wen, Jiexia

2012-11-04

To construct recombinant adenovirus containing canine interferon-gamma (cIFN-gamma) gene and to investigate its antiviral activity against canine parvovirus in Madin-Darby canine kidney cells (MDCK). [Methods] The cIFN-gamma gene was inserted into adenovirus shuttle plasmid to construct pShuttle3-cIFN-gamma expression vector, from which the cIFN-gamma expression cassette was transferred into the adenovirus genomic plasmid pAdeno-X by specific restriction sites to generate recombinant adenovirus genomic plasmid pAd-cIFN-gamma. The pAd-cIFN-gamma plasmid was linearized by digestion and transfected into human embryonic kidney (HEK) 293T cells to generate the replication-defective cIFN-gamma recombinant adenovirus (Ad-cIFN-gamma). To analyze its anti-canine parvovirus activity, the MDCK cells were pre-infected by Ad-cIFN-gamma recombinant adenovirus, and then infected by canine parvovirus. The antiviral activity of the Ad-cIFN-gamma recombinant adenovirus against parvovirus was analyzed. The recombinant adenovirus containing cIFN-gamma gene was constructed by the ligation method. The recombinant adenovirus could mediates recombinant cIFN-gamma secretory expression in MDCK cells. The Ad-cIFN-gamma recombinant adenovirus could significantly inhibit canine parvovirus replication in MDCK cells pre-infected with the recombinant adenovirus. These results indicate that the Ad-cIFN-gamma recombinant adenovirus has the potent antiviral activity against canine parvovirus. The Ad-cIFN-gamma recombinant adenovirus was successfully constructed by the ligation method and possessed a powerful antiviral activity against canine parvovirus.

Structure Properties and Mechanisms of Action of Naturally Originated Phenolic Acids and Their Derivatives against Human Viral Infections.

PubMed

Wu, Yi-Hang; Zhang, Bing-Yi; Qiu, Li-Peng; Guan, Rong-Fa; Ye, Zi-Hong; Yu, Xiao-Ping

2017-01-01

A great effort has been made to develop efficacious antiviral drugs, but many viral infections are still lack of efficient antiviral therapies so far. The related exploration of natural products to fight viruses has been raised in recent years. Natural compounds with structural diversity and complexity offer a great chance to find new antiviral agents. Particularly, phenolic acids have attracted considerable attention owing to their potent antiviral abilities and unique mechanisms. The aim of this review is to report new discoveries and updates pertaining to antiviral phenolic acids. The relevant references on natural phenolic acids were searched. The antiviral phenolic acids were classified according to their structural properties and antiviral types. Meanwhile, the antiviral characteristics and structure-activity relationships of phenolic acids and their derivatives were summarized. The review finds that natural phenolic acids and their derivatives possessed potent inhibitory effects on multiple virus in humans such as human immunodeficiency virus, hepatitis C virus, hepatitis B virus, herpes simplex virus, influenza virus and respiratory syncytial virus. In particular, caffeic acid/gallic acid and their derivatives exhibited outstanding antiviral properties by a variety of modes of action. Naturally derived phenolic acids especially caffeic acid/gallic acid and their derivatives may be regarded as novel promising antiviral leads or candidates. Additionally, scarcely any of these compounds has been used as antiviral treatment in clinical practice. Therefore, these phenolic acids with diverse skeletons and mechanisms provide us an excellent resource for finding novel antiviral drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

An antiviral protein from Bougainvillea spectabilis roots; purification and characterisation.

PubMed

Balasaraswathi, R; Sadasivam, S; Ward, M; Walker, J M

1998-04-01

An antiviral protein active against mechanical transmission of tomato spotted wilt virus was identified in the root tissues of Bougainvillea spectabilis Willd. Bougainvillea Antiviral Protein I (BAP I) was purified to apparent homogeneity from the roots of Bougainvillea by ammonium sulphate precipitation, CM- and DEAE-Sepharose chromatography and reverse phase HPLC. BAP I is a highly basic protein (pI value > 8.6) with an Mr of 28,000. The N-terminal sequence of BAP I showed homology with other plant antiviral proteins. Preliminary tests suggest that purified BAP I is capable of interfering with in vitro protein synthesis.

Stability of human interferon-beta 1: oligomeric human interferon-beta 1 is inactive but is reactivated by monomerization.

PubMed

Utsumi, J; Yamazaki, S; Kawaguchi, K; Kimura, S; Shimizu, H

1989-10-05

Human interferon-beta 1 is extremely stable is a low ionic strength solution of pH 2 such as 10 mM HCl at 37 degrees C. However, the presence of 0.15 M NaCl led to a remarkable loss of antiviral activity. The molecular-sieve high-performance liquid chromatography revealed that, whereas completely active human interferon-beta 1 eluted as a 25 kDa species (monomeric form), the inactivated preparation eluted primarily as a 90 kDa species (oligomeric form). The specific activity (units per mg protein) of the oligomeric form was approx. 10% of that of the monomeric form. This observation shows that oligomeric human interferon-beta 1 is apparently in an inactive form. When the oligomeric eluate was resolved by polyacrylamide gel containing sodium dodecyl sulphate (SDS), it appeared to be monomeric under non-reducing conditions. Monomerization of the oligomeric human interferon-beta 1 by treatment with 1% SDS, fully regenerated its antiviral activity. These results suggest that the inactivation of the human interferon-beta 1 preparation was caused by its oligomerization via hydrophobic interactions without the formation of intermolecular disulphide bonds. These oligomers can be dissociated by SDS to restore biological activity.

Discovery of berberine based derivatives as anti-influenza agent through blocking of neuraminidase.

PubMed

Enkhtaivan, Gansukh; Muthuraman, Pandurangan; Kim, Doo Hwan; Mistry, Bhupendra

2017-10-15

In this study, we investigated the antiviral activity of newly synthesized berberine derivatives (BD) against influenza virus infection using several strains in in vitro and in silico. The CPE reduction, pre-incubation, NA activity inhibition and molecular docking assays were used for antiviral evaluation. The anti-influenza activities of BDs were stronger than plant-derived pure commercial berberine, and some of the BDs were more potent than control drug Oseltamivir. The cytotoxicity level was observed in the range 63.16-1639μg/mL for synthesized BDs. Additionally, BDs were detected as able to block influenza viral particles. We targeted neuraminidase one of the influenza surface protein for further probing. Moreover, BDs registered competitive NA inhibition activity comparing with Oseltamivir. The active site of viral NA subunit was fully blocked by BD as the same location as Oseltamivir. The binding energies between influenza NA subunit and BD-5 were higher than Oseltamivir. More H-bonds and NA residues were occupied by BD for stronger binding ability than Oseltamivir. These results indicated that BD inhibits various strains of influenza virus by blocking of viral NA subunit. Copyright © 2017. Published by Elsevier Ltd.

Alveolar macrophage–derived type I interferons orchestrate innate immunity to RSV through recruitment of antiviral monocytes

PubMed Central

Goritzka, Michelle; Makris, Spyridon; Kausar, Fahima; Durant, Lydia R.; Pereira, Catherine; Kumagai, Yutaro; Culley, Fiona J.; Mack, Matthias; Akira, Shizuo

2015-01-01

Type I interferons (IFNs) are important for host defense from viral infections, acting to restrict viral production in infected cells and to promote antiviral immune responses. However, the type I IFN system has also been associated with severe lung inflammatory disease in response to respiratory syncytial virus (RSV). Which cells produce type I IFNs upon RSV infection and how this directs immune responses to the virus, and potentially results in pathological inflammation, is unclear. Here, we show that alveolar macrophages (AMs) are the major source of type I IFNs upon RSV infection in mice. AMs detect RSV via mitochondrial antiviral signaling protein (MAVS)–coupled retinoic acid–inducible gene 1 (RIG-I)–like receptors (RLRs), and loss of MAVS greatly compromises innate immune restriction of RSV. This is largely attributable to loss of type I IFN–dependent induction of monocyte chemoattractants and subsequent reduced recruitment of inflammatory monocytes (infMo) to the lungs. Notably, the latter have potent antiviral activity and are essential to control infection and lessen disease severity. Thus, infMo recruitment constitutes an important and hitherto underappreciated, cell-extrinsic mechanism of type I IFN–mediated antiviral activity. Dysregulation of this system of host antiviral defense may underlie the development of RSV-induced severe lung inflammation. PMID:25897172

[Antiviral and immunostimulating effect of maleic anhydride copolymers in experimental neuroviral infections].

PubMed

Davydova, A A; Stotskaia, L L; Berezina, L K; Osipova, L V; Barinskiĭ, I F

1986-01-01

The virus-inhibiting and immunostimulating activity of Soviet preparations, maleic anhydride copolymers, was demonstrated in alpha-, flavi-, and bunyavirus infections. Positive results were obtained in subcutaneous and intraperitoneal inoculations of the preparations used in prophylactic and therapeutic-prophylactic schedules. Stimulation of vaccination immunity was observed after combined use of copolymers and the vaccine against Eastern equine encephalomyelitis.

Mitochondrially localised MUL1 is a novel modulator of antiviral signaling.

PubMed

Jenkins, Kristie; Khoo, Jing Jing; Sadler, Anthony; Piganis, Rebecca; Wang, Die; Borg, Natalie A; Hjerrild, Kathryn; Gould, Jodee; Thomas, Belinda J; Nagley, Phillip; Hertzog, Paul J; Mansell, Ashley

2013-04-01

The innate immune response to virus must be balanced to eliminate infection yet limit damaging inflammation. A critical arm of the antiviral response is launched by the retinoic acid-inducible-gene I (RIG-I) protein. RIG-I is activated by viral RNA then associates with the mitochondrial antiviral signaling (MAVS) protein to subsequently induce potent inflammatory cytokines. Here, we demonstrate the mitochondrial E3 ubiquitin protein ligase 1 (MUL1) is a crucial moderator of RIG-I signaling. MUL1 is localized to the mitochondria where it interacts with MAVS and catalyzes RIG-I post-translational modifications that inhibit RIG-I-dependent cell signaling. Accordingly, depletion of MUL1 potentiated RIG-I mediated nuclear factor-kappa B (NF-κB) and interferon (IFN) β reporter activity. Moreover, depletion of MUL1 boosted the antiviral response and increased proinflammatory cytokines following challenge with the RNA mimetic poly I:C and Sendai virus. We therefore submit that MUL1 is a novel regulator of the RIG-I-like receptor-dependent antiviral response, that otherwise functions to limit inflammation.

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.

Current antiviral practice and course of Hepatitis B virus infection in inflammatory arthritis: a multicentric observational study (A + HBV study).

PubMed

Kalyoncu, Umut; Emmungil, Hakan; Onat, Ahmet Mesut; Yılmaz, Sedat; Kaşifoglu, Timuçin; Akar, Servet; İnanç, Nevsun; Yıldız, Fatih; Küçükşahin, Orhan; Karadağ, Ömer; Mercan, Rıdvan; Bes, Cemal; Yazısız, Veli; Yılmazer, Barış; Özmen, Mustafa; Erten, Şükran; Şenel, Soner; Yazıcı, Ayten; Taşçılar, Koray; Kalfa, Melike; Kiraz, Sedat; Kısacık, Bünyamin; Pehlivan, Yavuz; Kılıç, Levent; Şimşek, İsmail; Çefle, Ayşe; Akkoç, Nurullah; Direskeneli, Haner; Erken, Eren; Turgay, Murat; Öztürk, Mehmet Akif; Soy, Mehmet; Aksu, Kenan; Dinç, Ayhan; Ertenli, İhsan

2015-12-01

The reactivation of hepatitis B virus (HBV) infection is a well-known event in hepatitis B surface antigen (HbsAg)-positive patients receiving immunosuppressive therapy. The objective of this study was to assess the antiviral practice and course of HBV infection in inflammatory arthritis. Nineteen rheumatology centers participated in this retrospective study. HbsAg-positive patients who were taking disease-modifying antirheumatic drugs and who were being tested for HBV viral load at a minimum of two different time points were included. The case report form (CRF) consisted of demographic data, rheumatic diseases, treatment profiles, transaminase levels, viral hepatitis serological markers, and HBV viral load. The reactivation of HBV was defined as the abrupt rise in HBV replication by an increase in serum HBV DNA levels in a patient with a previously inactive HBV infection. In total, the data of 101 (female 50.5%) patients were included (76 patients with inactive HBV carriers and 25 patients with chronic HBV infection). The mean age of patients was 44±12 years, and the mean follow-up duration was 31±22 months. Of the 101 patients, 70 (69.3%) received antiviral treatment. HBV reactivation was detected in 13 of 76 (17.1%) patients with inactive HBV carriers. HBV reactivation was observed less frequently, not although significantly, in those patients receiving antiviral prophylaxis compared with those not receiving prophylaxis [5/41 (12.2%) vs. 8/33 (24.2%), p=0.17]. Forty-two patients (31 patients had inactive HBV carriers) were using anti-tumor necrosis factor agents. HBV reactivation was detected in 6 of the 31 (19.3%) patients. Twenty-five patients had chronic hepatitis, and five (20%) of them had not received antiviral prophylaxis. HBV viral loads were persistently elevated in 7 (28%) of 25 patients (three patients under and four patients not under antiviral treatment). HBV reactivation was observed in approximately 17% of patients under immunosuppressive treatments. HBV reactivation was more frequently observed in those who did not receive antiviral prophylaxis.

Current antiviral practice and course of Hepatitis B virus infection in inflammatory arthritis: a multicentric observational study (A + HBV study)

PubMed Central

Kalyoncu, Umut; Emmungil, Hakan; Onat, Ahmet Mesut; Yılmaz, Sedat; Kaşifoglu, Timuçin; Akar, Servet; İnanç, Nevsun; Yıldız, Fatih; Küçükşahin, Orhan; Karadağ, Ömer; Mercan, Rıdvan; Bes, Cemal; Yazısız, Veli; Yılmazer, Barış; Özmen, Mustafa; Erten, Şükran; Şenel, Soner; Yazıcı, Ayten; Taşçılar, Koray; Kalfa, Melike; Kiraz, Sedat; Kısacık, Bünyamin; Pehlivan, Yavuz; Kılıç, Levent; Şimşek, İsmail; Çefle, Ayşe; Akkoç, Nurullah; Direskeneli, Haner; Erken, Eren; Turgay, Murat; Öztürk, Mehmet Akif; Soy, Mehmet; Aksu, Kenan; Dinç, Ayhan; Ertenli, İhsan

2015-01-01

Objective The reactivation of hepatitis B virus (HBV) infection is a well-known event in hepatitis B surface antigen (HbsAg)-positive patients receiving immunosuppressive therapy. The objective of this study was to assess the antiviral practice and course of HBV infection in inflammatory arthritis. Material and Methods Nineteen rheumatology centers participated in this retrospective study. HbsAg-positive patients who were taking disease-modifying antirheumatic drugs and who were being tested for HBV viral load at a minimum of two different time points were included. The case report form (CRF) consisted of demographic data, rheumatic diseases, treatment profiles, transaminase levels, viral hepatitis serological markers, and HBV viral load. The reactivation of HBV was defined as the abrupt rise in HBV replication by an increase in serum HBV DNA levels in a patient with a previously inactive HBV infection. Results In total, the data of 101 (female 50.5%) patients were included (76 patients with inactive HBV carriers and 25 patients with chronic HBV infection). The mean age of patients was 44±12 years, and the mean follow-up duration was 31±22 months. Of the 101 patients, 70 (69.3%) received antiviral treatment. HBV reactivation was detected in 13 of 76 (17.1%) patients with inactive HBV carriers. HBV reactivation was observed less frequently, not although significantly, in those patients receiving antiviral prophylaxis compared with those not receiving prophylaxis [5/41 (12.2%) vs. 8/33 (24.2%), p=0.17]. Forty-two patients (31 patients had inactive HBV carriers) were using anti-tumor necrosis factor agents. HBV reactivation was detected in 6 of the 31 (19.3%) patients. Twenty-five patients had chronic hepatitis, and five (20%) of them had not received antiviral prophylaxis. HBV viral loads were persistently elevated in 7 (28%) of 25 patients (three patients under and four patients not under antiviral treatment). Conclusion HBV reactivation was observed in approximately 17% of patients under immunosuppressive treatments. HBV reactivation was more frequently observed in those who did not receive antiviral prophylaxis. PMID:27708953

Increased peripheral CD4+ regulatory T cells persist after successful direct-acting antiviral treatment of chronic hepatitis C.

PubMed

Langhans, Bettina; Nischalke, Hans Dieter; Krämer, Benjamin; Hausen, Annekristin; Dold, Leona; van Heteren, Peer; Hüneburg, Robert; Nattermann, Jacob; Strassburg, Christian P; Spengler, Ulrich

2017-05-01

CD4 + regulatory T cells (Tregs) expand during chronic hepatitis C virus (HCV) infection, inhibit antiviral immunity and promote fibrosis. Direct-acting antiviral agents (DAA) have revolutionized HCV therapy. However, it is unclear if Tregs are normalized after DAA-induced HCV elimination. We analyzed Tregs before (baseline), at end of therapy (EOT), 12 and 24weeks (SVR12, SVR24) and long-term (51±14weeks) after EOT in 26 genotype-1-infected patients who were successfully treated with sofosbuvir (SOF) plus interferon (IFN)/ribavirin (n=12) and IFN-free DAA regimens (SOF plus daclatasvir or simeprevir; n=14). Frequency, phenotype and suppressor function of peripheral Foxp3 + CD25 + CD4 + T cells were studied by multi-color flow cytometry and co-culture inhibition assays. Frequencies and activation status of Foxp3 + CD25 + CD4 + T cells remained elevated above those of normal controls in both treatment groups even long-term after HCV elimination. Co-culture assays indicated a dose-response relationship for functional inhibition of autologous CD4 + effector T cells and confirmed that activation of Tregs remained largely unchanged over the observation period. Unlike IFN-free regimens, SOF plus IFN/ribavirin induced a transiently increased frequency of Foxp3 + CD25 + CD4 + T cells at EOT (5.0% at baseline to 6.1% at EOT; p=0.001). These Foxp3 + CD25 + CD4 + T cells co-expressed the activation markers glycoprotein A repetitions predominant (GARP; p=0.012) and tumor necrosis factor receptor superfamily, member 4 (OX-40; p=0.001) but showed unchanged in vitro inhibitory activity. Although IFN-based DAA therapy induced transient expansion of activated Foxp3 + CD25 + CD4 + T cells, neither IFN-based nor IFN-free DAA regimens normalized frequencies and activation status of Tregs one year after viral elimination. Persistence of immunosuppressive Tregs may thus contribute to complications of liver disease even long-term after HCV cure. In chronic hepatitis C virus (HCV) infection, CD4 + regulatory T cells (Tregs) can reduce antiviral immune responses, promote liver fibrosis and may increase the risk for liver cancer, because they gradually expand during disease. Modern direct-acting antiviral agents (DAA) can "cure" hepatitis C in almost all treated patients. However, our study shows that DAA do not normalize the increased frequency and activation status of Tregs even long-term after HCV elimination. Tregs may persistently modulate functions of the immune system even after "cure" of hepatitis C. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Antiviral potential of medicinal plants against HIV, HSV, influenza, hepatitis, and coxsackievirus: A systematic review.

PubMed

Akram, Muhammad; Tahir, Imtiaz Mahmood; Shah, Syed Muhammad Ali; Mahmood, Zahed; Altaf, Awais; Ahmad, Khalil; Munir, Naveed; Daniyal, Muhammad; Nasir, Suhaila; Mehboob, Huma

2018-05-01

Viral infections are being managed therapeutically through available antiviral regimens with unsatisfactory clinical outcomes. The refractory viral infections resistant to available antiviral drugs are alarming threats and a serious health concern. For viral hepatitis, the interferon and vaccine therapies solely are not ultimate solutions due to recurrence of hepatitis C virus. Owing to the growing incidences of viral infections and especially of resistant viral strains, the available therapeutic modalities need to be improved, complemented with the discovery of novel antiviral agents to combat refractory viral infections. It is widely accepted that medicinal plant heritage is nature gifted, precious, and fueled with the valuable resources for treatment of metabolic and infectious disorders. The aims of this review are to assemble the facts and to conclude the therapeutic potential of medicinal plants in the eradication and management of various viral diseases such as influenza, human immunodeficiency virus (HIV), herpes simplex virus (HSV), hepatitis, and coxsackievirus infections, which have been proven in diverse clinical studies. The articles, published in the English language since 1982 to 2017, were included from Web of Science, Cochrane Library, AMED, CISCOM, EMBASE, MEDLINE, Scopus, and PubMed by using relevant keywords including plants possessing antiviral activity, the antiviral effects of plants, and plants used in viral disorders. The scientific literature mainly focusing on plant extracts and herbal products with therapeutic efficacies against experimental models of influenza, HIV, HSV, hepatitis, and coxsackievirus were included in the study. Pure compounds possessing antiviral activity were excluded, and plants possessing activity against viruses other than viruses in inclusion criteria were excluded. Hundreds of plant extracts with antiviral effect were recognized. However, the data from only 36 families investigated through in vitro and in vivo studies met the inclusion criteria of this review. The inferences from scientific literature review, focusing on potential therapeutic consequences of medicinal plants on experimental models of HIV, HSV, influenza, hepatitis, and coxsackievirus have ascertained the curative antiviral potential of plants. Fifty-four medicinal plants belonging to 36 different families having antiviral potential were documented. Out of 54 plants, 27 individually belong to particular plant families. On the basis of the work of several independent research groups, the therapeutic potential of medicinal plants against listed common viral diseases in the region has been proclaimed. In this context, the herbal formulations as alternative medicine may contribute to the eradication of complicated viral infection significantly. The current review consolidates the data of the various medicinal plants, those are Sambucus nigra, Caesalpinia pulcherrima, and Hypericum connatum, holding promising specific antiviral activities scientifically proven through studies on experimental animal models. Consequently, the original research addressing the development of novel nutraceuticals based on listed medicinal plants is highly recommended for the management of viral disorders. Copyright © 2018 John Wiley & Sons, Ltd.

Antiviral Activity of Fridericia formosa (Bureau) L. G. Lohmann (Bignoniaceae) Extracts and Constituents

PubMed Central

Brandão, Geraldo Célio; Kroon, Erna G.; Souza Filho, José D.

2017-01-01

A phytochemical study of Fridericia formosa (Bignoniaceae) ethanol extracts of leaves, stems, and fruits was guided by in vitro assays against vaccinia virus Western Reserve (VACV-WR), human herpes virus 1 (HSV-1), murine encephalomyocarditis virus (EMCV), and dengue virus type 2 (DENV-2) by the MTT method. All the ethanol extracts were active against DENV-2, HSV-1, and VACV-WR with best results for the fruits extract against DENV-2 (SI > 38.2). For VACV-WR and HSV-1, EC50 values > 200 μg mL−1 were determined, while no inhibition of the cytopathic effect was observed with EMCV. Five compounds were isolated and identified as the C-glucosylxanthones mangiferin (1), 2′-O-trans-caffeoylmangiferin (2), 2′-O-trans-coumaroylmangiferin (3), 2′-O-trans-cinnamoylmangiferin (5), and the flavonoid chrysin (4). The most active compound was 2′-O-trans-coumaroylmangiferin (3) with SI > 121.9 against DENV-2 and 108.7 for HSV-1. These results indicate that mangiferin cinnamoyl esters might be potential antiviral drugs. PMID:28634494

Phytochemical screening, cytotoxicity and antiviral activity of hexane fraction of Phaleria macrocarpa fruits

NASA Astrophysics Data System (ADS)

Ismaeel, Mahmud Yusef Yusef; Yaacob, Wan Ahmad; Tahir, Mariya Mohd.; Ibrahim, Nazlina

2015-09-01

Phaleria macrocarpa fruits have been widely used in the traditional medicine for the treatment of several infections. The current study was done to determine the phytochemical content, cytotoxicity and antiviral activity of the hexane fraction (HF) of P. macrocarpa fruits. In the hexane fraction of P. macarocarpa fruits, phytochemical screening showed the presence of terpenoids whereas saponins, alkaloids, tannins and anthraquinones were not present. Evaluation on Vero cell lines by using MTT assay showed that the 50% cytotoxic concentration (CC50) value was 0.48 mg/mL indicating that the fraction is not cytotoxic. Antiviral properties of the plant extracts were determined by plaque reduction assay. The effective concentration (EC50) was 0.18 mg/mL. Whereas the selective index (SI = CC50/EC50) of hexane fraction is 2.6 indicating low to moderate potential as antiviral agent.

An antiviral RISC isolated from Tobacco rattle virus-infected plants

PubMed Central

Ciomperlik, Jessica J.; Omarov, Rustem T.; Scholthof, Herman B.

2011-01-01

The RNAi model predicts that during antiviral defense a RNA-induced silencing complex (RISC) is programmed with viral short-interfering RNAs (siRNAs) to target the cognate viral RNA for degradation. We show that infection of Nicotiana benthamiana with Tobacco rattle virus (TRV) activates an antiviral nuclease that specifically cleaves TRV RNA in vitro. In agreement with known RISC properties, the nuclease activity was inhibited by NaCl and EDTA and stimulated by divalent metal cations; a novel property was its preferential targeting of elongated RNA molecules. Intriguingly, the specificity of the TRV RISC could be re-programmed by exogenous addition of RNA (containing siRNAs) from plants infected with an unrelated virus, resulting in a newly acquired ability of RISC to target this heterologous genome in vitro. Evidently the virus-specific nuclease complex from N. benthamiana represents a genuine RISC that functions as a readily employable and reprogrammable antiviral defense unit. PMID:21272908

[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.

The Antiviral Effect of Baicalin on Enterovirus 71 In Vitro

PubMed Central

Li, Xiang; Liu, Yuanyuan; Wu, Tingting; Jin, Yue; Cheng, Jianpin; Wan, Changbiao; Qian, Weihe; Xing, Fei; Shi, Weifeng

2015-01-01

Baicalin is a flavonoid compound extracted from Scutellaria roots that has been reported to possess antibacterial, anti-inflammatory, and antiviral activities. However, the antiviral effect of baicalin on enterovirus 71 (EV71) is still unknown. In this study, we found that baicalin showed inhibitory activity on EV71 infection and was independent of direct virucidal or prophylactic effect and inhibitory viral absorption. The expressions of EV71/3D mRNA and polymerase were significantly blocked by baicalin treatment at early stages of EV71 infection. In addition, baicalin could decrease the expressions of FasL and caspase-3, as well as inhibit the apoptosis of EV71-infected human embryonal rhabdomyosarcoma (RD) cells. Altogether, these results indicate that baicalin exhibits potent antiviral effect on EV71 infection, probably through inhibiting EV71/3D polymerase expression and Fas/FasL signaling pathways. PMID:26295407

Antiviral activity of formyl peptide receptor 2 antagonists against influenza viruses.

PubMed

Courtin, Noémie; Fotso, Aurélien Fotso; Fautrad, Pierre; Mas, Floriane; Alessi, Marie-Christine; Riteau, Béatrice

2017-07-01

Influenza viruses are one of the most important respiratory pathogens worldwide, causing both epidemic and pandemic infections. The aim of the study was to evaluate the effect of FPR2 antagonists PBP10 and BOC2 on influenza virus replication. We determined that these molecules exhibit antiviral effects against influenza A (H1N1, H3N2, H6N2) and B viruses. FPR2 antagonists used in combination with oseltamivir showed additive antiviral effects. Mechanistically, the antiviral effect of PBP10 and BOC2 is mediated through early inhibition of virus-induced ERK activation. Finally, our preclinical studies showed that FPR2 antagonists protected mice from lethal infections induced by influenza, both in a prophylactic and therapeutic manner. Thus, FPR2 antagonists might be explored for novel treatments against influenza. Copyright © 2017 Elsevier B.V. All rights reserved.

Cytotoxicity and antiviral activities of Asplenium nidus, Phaleria macrocarpa and Eleusine indica

NASA Astrophysics Data System (ADS)

Tahir, Mariya Mohd; Ibrahim, Nazlina; Yaacob, Wan Ahmad

2014-09-01

Three local medicinal plants namely Asplenium nidus (langsuyar), Eleusine indica (sambau) and Phaleria macrocarpa (mahkota dewa) were screened for the cytotoxicity and antiviral activities. Six plant extracts were prepared including the aqueous and methanol extracts from A. nidus leaf and root, aqueous extract from dried whole plant of E. indica and methanol extract from P. macrocarpa fruits. Cytotoxicity screening in Vero cell line by MTT assay showed that the CC50 values ranged from 15 to 60 mg/mL thus indicating the safety of the extracts even at high concentrations. Antiviral properties of the plant extracts were determined by plaque reduction assay. The EC50 concentrations were between 3.2 to 47 mg/mL. The selectivity indices (SI = CC50/EC50) of each tested extracts ranged from 4.3 to 63.25 indicating the usefulness of the extracts as potential antiviral agents.

Viruses and Antiviral Immunity in Drosophila

PubMed Central

Xu, Jie; Cherry, Sara

2013-01-01

Viral pathogens present many challenges to organisms, driving the evolution of a myriad of antiviral strategies to combat infections. A wide variety of viruses infect invertebrates, including both natural pathogens that are insect-restricted, and viruses that are transmitted to vertebrates. Studies using the powerful tools available in the model organism Drosophila have expanded our understanding of antiviral defenses against diverse viruses. In this review, we will cover three major areas. First, we will describe the tools used to study viruses in Drosophila. Second, we will survey the major viruses that have been studied in Drosophila. And lastly, we will discuss the well-characterized mechanisms that are active against these diverse pathogens, focusing on non-RNAi mediated antiviral mechanisms. Antiviral RNAi is discussed in another paper in this issue. PMID:23680639

Viruses and antiviral immunity in Drosophila.

PubMed

Xu, Jie; Cherry, Sara

2014-01-01

Viral pathogens present many challenges to organisms, driving the evolution of a myriad of antiviral strategies to combat infections. A wide variety of viruses infect invertebrates, including both natural pathogens that are insect-restricted, and viruses that are transmitted to vertebrates. Studies using the powerful tools in the model organism Drosophila have expanded our understanding of antiviral defenses against diverse viruses. In this review, we will cover three major areas. First, we will describe the tools used to study viruses in Drosophila. Second, we will survey the major viruses that have been studied in Drosophila. And lastly, we will discuss the well-characterized mechanisms that are active against these diverse pathogens, focusing on non-RNAi mediated antiviral mechanisms. Antiviral RNAi is discussed in another paper in this issue. Copyright © 2013 Elsevier Ltd. All rights reserved.

Towards depersonalized abacavir therapy: chemical modification eliminates HLA-B*57 : 01-restricted CD8+ T-cell activation.

PubMed

Naisbitt, Dean J; Yang, Emma L; Alhaidari, Mohammad; Berry, Neil G; Lawrenson, Alexandre S; Farrell, John; Martin, Philip; Strebel, Klaus; Owen, Andrew; Pye, Matthew; French, Neil S; Clarke, Stephen E; O'Neill, Paul M; Park, B Kevin

2015-11-28

Exposure to abacavir is associated with T-cell-mediated hypersensitivity reactions in individuals carrying human leukocyte antigen (HLA)-B57 : 01. To activate T cells, abacavir interacts directly with endogenous HLA-B57 : 01 and HLA-B57 : 01 expressed on the surface of antigen presenting cells. We have investigated whether chemical modification of abacavir can produce a molecule with antiviral activity that does not bind to HLA-B57 : 01 and activate T cells. An interdisciplinary laboratory study using samples from human donors expressing HLA-B57 : 01. Researchers were blinded to the analogue structures and modelling data. Sixteen 6-amino substituted abacavir analogues were synthesized. Computational docking studies were completed to predict capacity for analogue binding within HLA-B57 : 01. Abacavir-responsive CD8 clones were generated to study the association between HLA-B57 : 01 analogue binding and T-cell activation. Antiviral activity and the direct inhibitory effect of analogues on proliferation were assessed. Major histocompatibility complex class I-restricted CD8 clones proliferated and secreted IFNγ following abacavir binding to surface and endogenous HLA-B57 : 01. Several analogues retained antiviral activity and showed no overt inhibitory effect on proliferation, but displayed highly divergent antigen-driven T-cell responses. For example, abacavir and N-propyl abacavir were equally potent at activating clones, whereas the closely related analogues N-isopropyl and N-methyl isopropyl abacavir were devoid of T-cell activity. Docking abacavir analogues to HLA-B57 : 01 revealed a quantitative relationship between drug-protein binding and the T-cell response. These studies demonstrate that the unwanted T-cell activity of abacavir can be eliminated whilst maintaining the favourable antiviral profile. The in-silico model provides a tool to aid the design of safer antiviral agents that may not require a personalized medicines approach to therapy.

The Antiviral Mechanism of an Influenza A Virus Nucleoprotein-Specific Single-Domain Antibody Fragment

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

Hanke, Leo; Knockenhauer, Kevin E.; Brewer, R. Camille

Alpaca-derived single-domain antibody fragments (VHHs) that target the influenza A virus nucleoprotein (NP) can protect cells from infection when expressed in the cytosol. We found that one such VHH, αNP-VHH1, exhibits antiviral activity similar to that of Mx proteins by blocking nuclear import of incoming viral ribonucleoproteins (vRNPs) and viral transcription and replication in the nucleus. We determined a 3.2-Å crystal structure of αNP-VHH1 in complex with influenza A virus NP. The VHH binds to a nonconserved region on the body domain of NP, which has been associated with binding to host factors and serves as a determinant of hostmore » range. Several of the NP/VHH interface residues determine sensitivity of NP to antiviral Mx GTPases. The structure of the NP/αNP-VHH1 complex affords a plausible explanation for the inhibitory properties of the VHH and suggests a rationale for the antiviral properties of Mx proteins. Such knowledge can be leveraged for much-needed novel antiviral strategies. IMPORTANCEInfluenza virus strains can rapidly escape from protection afforded by seasonal vaccines or acquire resistance to available drugs. Additional ways to interfere with the virus life cycle are therefore urgently needed. The influenza virus nucleoprotein is one promising target for antiviral interventions. We have previously isolated alpaca-derived single-domain antibody fragments (VHHs) that protect cells from influenza virus infection if expressed intracellularly. We show here that one such VHH exhibits antiviral activities similar to those of proteins of the cellular antiviral defense (Mx proteins). We determined the three-dimensional structure of this VHH in complex with the influenza virus nucleoprotein and identified the interaction site, which overlaps regions that determine sensitivity of the virus to Mx proteins. Our data define a new vulnerability of influenza virus, help us to better understand the cellular antiviral mechanisms, and provide a well-characterized tool to further study them.« less

Prediction of antiviral peptides derived from viral fusion proteins potentially active against herpes simplex and influenza A viruses

PubMed Central

Jesús, Torres; Rogelio, López; Abraham, Cetina; Uriel, López; J- Daniel, García; Alfonso, Méndez-Tenorio; Lilia, Barrón Blanca

2012-01-01

There are very few antiviral drugs available to fight viral infections and the appearance of viral strains resistant to these antivirals is not a rare event. Hence, the design of new antiviral drugs is important. We describe the prediction of peptides with antiviral activity (AVP) derived from the viral glycoproteins involved in the entrance of herpes simplex (HSV) and influenza A viruses into their host cells. It is known, that during this event viral glycoproteins suffer several conformational changes due to protein-protein interactions, which lead to membrane fusion between the viral envelope and the cellular membrane. Our hypothesis is that AVPs can be derived from these viral glycoproteins, specifically from regions highly conserved in amino acid sequences, which at the same time have the physicochemical properties of being highly exposed (antigenic), hydrophilic, flexible, and charged, since these properties are important for protein-protein interactions. For that, we separately analyzed the HSV glycoprotein H and B, and influenza A viruses hemagglutinin (HA), using several bioinformatics tools. A set of multiple alignments was carried out, to find the most conserved regions in the amino acid sequences. Then, the physicochemical properties indicated above were analyzed. We predicted several peptides 12-20 amino acid length which by docking analysis were able to interact with the fusion viral glycoproteins and thus may prevent conformational changes in them, blocking the viral infection. Our strategy to design AVPs seems to be very promising since the peptides were synthetized and their antiviral activities have produced very encouraging results. PMID:23144542

Pandemic pharmaceutical dosing effects on wastewater treatment: no adaptation of activated sludge bacteria to degrade the antiviral drug oseltamivir (Tamiflu®) and loss of nutrient removal performance.

PubMed

Slater, Frances R; Singer, Andrew C; Turner, Susan; Barr, Jeremy J; Bond, Philip L

2011-02-01

The 2009-2010 influenza pandemic saw many people treated with antivirals and antibiotics. High proportions of both classes of drugs are excreted and enter wastewater treatment plants (WWTPs) in biologically active forms. To date, there has been no study into the potential for influenza pandemic-scale pharmaceutical use to disrupt WWTP function. Furthermore, there is currently little indication as to whether WWTP microbial consortia can degrade antiviral neuraminidase inhibitors when exposed to pandemic-scale doses. In this study, we exposed an aerobic granular sludge sequencing batch reactor, operated for enhanced biological phosphorus removal (EBPR), to a simulated influenza-pandemic dosing of antibiotics and antivirals for 8 weeks. We monitored the removal of the active form of Tamiflu(®), oseltamivir carboxylate (OC), bacterial community structure, granule structure and changes in EBPR and nitrification performance. There was little removal of OC by sludge and no evidence that the activated sludge community adapted to degrade OC. There was evidence of changes to the bacterial community structure and disruption to EBPR and nitrification during and after high-OC dosing. This work highlights the potential for the antiviral contamination of receiving waters and indicates the risk of destabilizing WWTP microbial consortia as a result of high concentrations of bioactive pharmaceuticals during an influenza pandemic. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

A new mechanism of interferon's antiviral action: Induction of autophagy, essential for paramyxovirus replication, is inhibited by the interferon stimulated gene, TDRD7.

PubMed

Subramanian, Gayatri; Kuzmanovic, Teodora; Zhang, Ying; Peter, Cara Beate; Veleeparambil, Manoj; Chakravarti, Ritu; Sen, Ganes C; Chattopadhyay, Saurabh

2018-01-01

The interferon (IFN) system represents the first line of defense against a wide range of viruses. Virus infection rapidly triggers the transcriptional induction of IFN-β and IFN Stimulated Genes (ISGs), whose protein products act as viral restriction factors by interfering with specific stages of virus life cycle, such as entry, transcription, translation, genome replication, assembly and egress. Here, we report a new mode of action of an ISG, IFN-induced TDRD7 (tudor domain containing 7) inhibited paramyxovirus replication by inhibiting autophagy. TDRD7 was identified as an antiviral gene by a high throughput screen of an ISG shRNA library for blocking IFN's protective effect against Sendai virus (SeV) replication. The antiviral activity of TDRD7 against SeV, human parainfluenza virus 3 and respiratory syncytial virus was confirmed by its genetic ablation or ectopic expression in several types of mouse and human cells. TDRD7's antiviral action was mediated by its ability to inhibit autophagy, a cellular catabolic process which was robustly induced by SeV infection and required for its replication. Mechanistic investigation revealed that TDRD7 interfered with the activation of AMP-dependent kinase (AMPK), an enzyme required for initiating autophagy. AMPK activity was required for efficient replication of several paramyxoviruses, as demonstrated by its genetic ablation or inhibition of its activity by TDRD7 or chemical inhibitors. Therefore, our study has identified a new antiviral ISG with a new mode of action.

The antiviral potency of Fagus sylvatica 4OMe-glucuronoxylan sulfates.

PubMed

Pujol, C A; Damonte, E B; Turjan, J; Yanbo, K Z; Capek, P

2016-06-01

Herpes simplex virus belongs to Herpesviridae family and causes infection of humans from ancient times. 4OMe-glucuronoxylans as the renewable biopolymers can be promising glycomaterials for various applications in pharmacy. Control enzymatic degradation of the native 4OMe-glucuronoxylan (GX1) followed by targeted sulfation procedure afforded a range of 4OMe-glucuronoxylan sulfates differed in the degree of sulfation (10-16%) and molecular mass (21,000-5000g/mol; GXS1>GXS2>GXS3>GXS4). Antiviral activity tests on GXS1-4 against herpes simplex virus (HSV) types 1 and 2 revealed the positive effect of all compounds against strains of herpes virus. Of them, the compounds GXS1 and GXS4 were shown to be the most active for both HSV serotypes. The antiviral activity of GXS1 and GXS4 was similar to those of heparin or dextran sulfate, used as reference compounds. It was found that GXS1 and GXS4 were active as well against Polio and dengue viruses, however, on a smaller scale. The mode of antiviral action of 4OMe-glucuronoxylan sulfates is due to inhibition of the virus binding to the cell receptors. Copyright © 2016 Elsevier B.V. All rights reserved.

RNase L Interacts with Filamin A To Regulate Actin Dynamics and Barrier Function for Viral Entry

PubMed Central

Siddiqui, Mohammad Adnan; Dayal, Shubham; Naji, Merna; Ezelle, Heather J.; Zeng, Chun; Zhou, Aimin; Hassel, Bret A.

2014-01-01

ABSTRACT The actin cytoskeleton and its network of associated proteins constitute a physical barrier that viruses must circumvent to gain entry into cells for productive infection. The mechanisms by which the physical signals of infection are sensed by the host to activate an innate immune response are not well understood. The antiviral endoribonuclease RNase L is ubiquitously expressed in a latent form and activated upon binding 2-5A, a unique oligoadenylate produced during viral infections. We provide evidence that RNase L in its inactive form interacts with the actin-binding protein Filamin A to modulate the actin cytoskeleton and inhibit virus entry. Cells lacking either RNase L or Filamin A displayed increased virus entry which was exacerbated in cells lacking both proteins. RNase L deletion mutants that reduced Filamin A interaction displayed a compromised ability to restrict virus entry, supporting the idea of an important role for the RNase L-Filamin A complex in barrier function. Remarkably, both the wild type and a catalytically inactive RNase L mutant were competent to reduce virus entry when transfected into RNase L-deficient cells, indicating that this novel function of RNase L is independent of its enzymatic activity. Virus infection and RNase L activation disrupt its association with Filamin A and release RNase L to mediate its canonical nuclease-dependent antiviral activities. The dual functions of RNase L as a constitutive component of the actin cytoskeleton and as an induced mediator of antiviral signaling and effector functions provide insights into its mechanisms of antiviral activity and opportunities for the development of novel antiviral agents. PMID:25352621

Antiviral activity of double-stranded RNA-binding protein PACT against influenza A virus mediated via suppression of viral RNA polymerase.

PubMed

Chan, Chi-Ping; Yuen, Chun-Kit; Cheung, Pak-Hin Hinson; Fung, Sin-Yee; Lui, Pak-Yin; Chen, Honglin; Kok, Kin-Hang; Jin, Dong-Yan

2018-03-07

PACT is a double-stranded RNA-binding protein that has been implicated in host-influenza A virus (IAV) interaction. PACT facilitates the action of RIG-I in the activation of the type I IFN response, which is suppressed by the viral nonstructural protein NS1. PACT is also known to interact with the IAV RNA polymerase subunit PA. Exactly how PACT exerts its antiviral activity during IAV infection remains to be elucidated. In the current study, we demonstrated the interplay between PACT and IAV polymerase. Induction of IFN-β by the IAV RNP complex was most robust when both RIG-I and PACT were expressed. PACT-dependent activation of IFN-β production was suppressed by the IAV polymerase subunits, polymerase acidic protein, polymerase basic protein 1 (PB1), and PB2. PACT associated with PA, PB1, and PB2. Compromising PACT in IAV-infected A549 cells resulted in the augmentation of viral RNA (vRNA) transcription and replication and IFN-β production. Furthermore, vRNA replication was boosted by knockdown of PACT in both A549 cells and IFN-deficient Vero cells. Thus, the antiviral activity of PACT is mediated primarily via its interaction with and inhibition of IAV polymerase. Taken together, our findings reveal a new facet of the host-IAV interaction in which the interplay between PACT and IAV polymerase affects the outcome of viral infection and antiviral response.-Chan, C.-P., Yuen, C.-K., Cheung, P.-H. H., Fung, S.-Y., Lui, P.-Y., Chen, H., Kok, K.-H., Jin, D.-Y. Antiviral activity of double-stranded RNA-binding protein PACT against influenza A virus mediated via suppression of viral RNA polymerase.

Comparative study on the antiherpetic activity of aqueous and ethanolic extracts derived from Cajanus cajan (L.) Millsp.

PubMed

Zu, Yuangang; Fu, Yujie; Wang, Wei; Wu, Nan; Liu, Wei; Kong, Yu; Schiebel, Hans-Martin; Schwarz, Günther; Schnitzler, Paul; Reichling, Jürgen

2010-03-01

Aqueous and ethanolic extracts of Cajanus cajan (Fabaceae) were examined in vitro for their antiviral activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The antiviral activity was determined using a plaque reduction assay. The cytotoxic concentration (CC50) as well as the inhibitory concentration (IC50) of the extracts was determined from dose-response curves. All extracts tested revealed a high antiviral activity against cell-free HSV-1 and HSV-2. The most active one was the Cajanus ethanol extract with IC50 values of 0.022 microg/ml for HSV-1 and 0.1 microg/ml for HSV-2. In order to identify the mode of antiviral action, the extracts were added to the host cells or viruses at different stages of infection. HSV-1 and HSV-2 were considerably inactivated when the viruses were pretreated with the extracts for 1 h prior to cell infection. At maximum non-cytotoxic concentrations of the extracts, plaque formation was significantly reduced by 95-99% for HSV-1 and HSV-2. In a time-dependent assay with cell-free HSV-1 over a period of 2 h, a clearly time-dependent effect was demonstrated whereby the Cajanus ethanol extract revealed a much higher activity than the Cajanus aqueous one. The results obtained indicate that the extracts affect HSV before cell adsorption, but have no effect on the intracellular virus replication. According to our findings, a therapeutic application of Cajanus ethanolic extracts containing crème or ointment as antiviral agent in recurrent HSV infection appears to be promising. Copyright (c) 2010 S. Karger AG, Basel.

Formononetin inhibits enterovirus 71 replication by regulating COX- 2/PGE₂ expression.

PubMed

Wang, Huiqiang; Zhang, Dajun; Ge, Miao; Li, Zhuorong; Jiang, Jiandong; Li, Yuhuan

2015-03-01

The activation of ERK, p38 and JNK signal cascade in host cells has been demonstrated to up-regulate of enterovirus 71 (EV71)-induced cyclooxygenase-2 (COX-2)/ prostaglandins E2 (PGE₂) expression which is essential for viral replication. So, we want to know whether a compound can inhibit EV71 infection by suppressing COX-2/PGE₂ expression. The antiviral effect of formononetin was determined by cytopathic effect (CPE) assay and the time course assays. The influence of formononetin for EV71 replication was determined by immunofluorescence assay, western blotting assay and qRT-PCR assay. The mechanism of the antiviral activity of formononetin was determined by western blotting assay and ELISA assay. Formononetin could reduce EV71 RNA and protein synthesis in a dose-dependent manner. The time course assays showed that formononetin displayed significant antiviral activity both before (24 or 12 h) and after (0-6 h) EV71 inoculation in SK-N-SH cells. Formononetin was also able to prevent EV71-induced cytopathic effect (CPE) and suppress the activation of ERK, p38 and JNK signal pathways. Furthermore, formononetin could suppress the EV71-induced COX-2/PGE₂ expression. Also, formononetin exhibited similar antiviral activities against other members of Picornaviridae including coxsackievirus B2 (CVB2), coxsackievirus B3 (CVB3) and coxsackievirus B6 (CVB6). Formononetin could inhibit EV71-induced COX-2 expression and PGE₂ production via MAPKs pathway including ERK, p38 and JNK. Formononetin exhibited antiviral activities against some members of Picornaviridae. These findings suggest that formononetin could be a potential lead or supplement for the development of new anti-EV71 agents in the future.

Mx1, Mx2 and Mx3 proteins from the gilthead seabream (Sparus aurata) show in vitro antiviral activity against RNA and DNA viruses.

PubMed

Fernández-Trujillo, M A; García-Rosado, E; Alonso, M C; Castro, D; Álvarez, M C; Béjar, J

2013-12-01

Mx proteins are important components of the antiviral innate immune response mediated by type I interferon. Classically, these proteins have been considered to be triggered by viral RNA, thus showing activity against RNA viruses. Actually, three Mx proteins (SauMx1, SauMx2 and SauMx3) from gilthead seabream (Sparus aurata) have previously shown antiviral activity against a dsRNA virus: the infectious pancreatic necrosis virus (IPNV) in vitro. For further characterizing their antiviral spectrum, the activity of SauMx proteins were tested against three different viral pathogens of fish: the lymphocystis disease virus (LCDV, a dsDNA virus), a pathogen of gilthead seabream; the viral haemorrhagic septicaemia virus (VHSV, a ssRNA virus), to which gilthead seabream is considered a reservoir species; and the European sheatfish virus (ESV, a dsDNA virus), that has not been detected in gilthead seabream to date. Three clonal populations of CHSE-214 cells developed in a previous study, stably expressing SauMx1, SauMx2 and SauMx3, respectively, were challenged with the three viruses. Results combining cytopathic effects and virus yield reduction assays showed that SauMx1 protected the cells against VHSV and LCDV, SauMx2 protected against ESV and LCDV, and SauMx3 showed activity only against VHSV. This study, besides confirming the antiviral activity of the three gilthead seabream Mx proteins, is the first report of the protective effect of a fish Mx against DNA viruses. Additionally, it discloses a clear specificity between Mx proteins and virus targets, supporting the idea that the relationship between virus and Mx proteins is finely tuned. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quantitative Assay of Pyrazofurin a New Antiviral, Antitumor Antibiotic1

PubMed Central

Westhead, J. E.; Price, H. D.

1974-01-01

Pyrazofurin, a carbon-linked nucleoside, has been previously reported to possess antiviral and antitumor activity. The antagonistic effect of pyrazofurin against Neurospora crassa has been utilized to develop a quantitative assay for the compound. PMID:4275616

(D)- and (L)-cyclohexenyl-G, a new class of antiviral agents: synthesis, conformational analysis, molecular modeling, and biological activity.

PubMed

Wang, J; Froeyen, M; Hendrix, C; Andrei, C; Snoeck, R; Lescrinier, E; De Clercq, E; Herdewijn, P

2001-01-01

(D)- and (L)-cyclohexeneyl-G were synthesized enantioselectively starting from (R)-carvone. Both show potent and selective anti-herpesvirus activity (HSV-1, HSV-2, VZV, CMV). Molecular modeling demonstrates that both isomers are bound in the active site of HSV-1 thymidine kinase in a high-energy conformation with the base moiety orienting in an equatorial position. It is believed that the flexibility of the cyclohexene ring is essential for their antiviral activity.

Differential antiviral activities of respiratory syncytial virus (RSV) inhibitors in human airway epithelium.

PubMed

Mirabelli, Carmen; Jaspers, Martine; Boon, Mieke; Jorissen, Mark; Koukni, Mohamed; Bardiot, Dorothée; Chaltin, Patrick; Marchand, Arnaud; Neyts, Johan; Jochmans, Dirk

2018-03-27

We report the use of reconstituted 3D human airway epithelium cells (HuAECs) of bronchial origin in an air-liquid interface to study respiratory syncytial virus (RSV) infection and to assess the efficacy of RSV inhibitors in (pre-)clinical development. HuAECs were infected with RSV-A Long strain (0.01 CCID50/cell, where CCID50 represents 50% cell culture infectious dose in HEp2 cells) on the apical compartment of the culture. At the time of infection or at 1 or 3 days post-infection, selected inhibitors were added and refreshed daily on the basal compartment of the culture. Viral shedding was followed up by apical washes collected daily and quantifying viral RNA by RT-qPCR. RSV-A replicates efficiently in HuAECs and viral RNA is shed for weeks after infection. RSV infection reduces the ciliary beat frequency of the ciliated cells as of 4 days post-infection, with complete ciliary dyskinesia observed by day 10. Treatment with RSV fusion inhibitors resulted in an antiviral effect only when added at the time of infection. In contrast, the use of replication inhibitors (both nucleoside and non-nucleoside) elicited a marked antiviral effect even when the start of treatment was delayed until 1 day or even 3 days after infection. Levels of the inflammation marker RANTES (mRNA) increased ∼200-fold in infected, untreated cultures (at 3 weeks post-infection), but levels were comparable to those of uninfected cultures in the presence of PC786, an RSV replication inhibitor, suggesting that an efficient antiviral treatment might inhibit virus-induced inflammation in this model. Overall, HuAECs offer a robust and physiologically relevant model to study RSV replication and to assess the efficacy of antiviral compounds.

Alisporivir Has Limited Antiviral Effects Against Ebola Virus Strains Makona and Mayinga.

PubMed

Chiramel, Abhilash I; Banadyga, Logan; Dougherty, Jonathan D; Falzarano, Darryl; Martellaro, Cynthia; Brees, Dominique; Taylor, R Travis; Ebihara, Hideki; Best, Sonja M

2016-10-15

Antiviral therapeutics with existing clinical safety profiles would be highly desirable in an outbreak situation, such as the 2013-2016 emergence of Ebola virus (EBOV) in West Africa. Although, the World Health Organization declared the end of the outbreak early 2016, sporadic cases of EBOV infection have since been reported. Alisporivir is the most clinically advanced broad-spectrum antiviral that functions by targeting a host protein, cyclophilin A (CypA). A modest antiviral effect of alisporivir against contemporary (Makona) but not historical (Mayinga) EBOV strains was observed in tissue culture. However, this effect was not comparable to observations for an alisporivir-susceptible virus, the flavivirus tick-borne encephalitis virus. Thus, EBOV does not depend on (CypA) for replication, in contrast to many other viruses pathogenic to humans. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Chemical composition of Propolis Extract ACF® and activity against herpes simplex virus.

PubMed

Bankova, V; Galabov, A S; Antonova, D; Vilhelmova, N; Di Perri, B

2014-09-25

Propolis Extract ACF(®) (PPE) is a purified extract manufactured from propolis collected in a Canadian region rich in poplar trees, and it is the active substance of a topical ointment used against herpes labialis (cold sores or fever blisters). Aim of this study was to analyze the chemical composition of PPE in order to understand the plant origin and possible relations between compounds and antiviral activity, and to characterize the antiviral activity of the extract against herpes simplex virus in vitro. The analysis of the propolis extract samples was conducted by Gas Chromatography-Mass Spectrometry (GC-MS). The antiviral activity was tested against herpes simplex viruses type 1 and type 2 in MDBK cell cultures by treating the cells with PPE at the time of virus adsorption, and by incubating the virus with the extract before infection (virucidal assay). Results from the GC-MS analyses revealed a dual plant origin of PPE, with components derived from resins of two different species of poplar. The chemical composition appeared standardized between extract samples and was also reproduced in the sample of topical ointment. The antiviral studies showed that PPE had a pronounced virucidal effect against herpes simplex viruses type 1 and type 2, and also interfered with virus adsorption. Copyright © 2014 Elsevier GmbH. All rights reserved.

2'-fluoro-5-iodo-aracytosine, a potent and selective anti-herpesvirus agent.

PubMed

Lopez, C; Watanabe, K A; Fox, J J

1980-05-01

A newly synthesized pyrimidine analog, 2'-fluoro-5-iodo-aracytosine (FIAC), suppressed by 90% the replication of various strains of herpes simplex virus types 1 and 2 at concentrations of 0.0025 to 0.0126 microM. Cytotoxicity was minimal, as determined by trypan blue dye exclusion with norman Vero, WI-38, and NC-37 cell proliferation; the 50% inhibitory dose was 4 to 10 microM in a 4-day assay. When compared with other antiviral drugs, FIAC was active at much lower concentrations than arabinosylcytosine, iododeoxyuridine, and arabinosyladenine. It was slightly more active against herpes simplex virus type 1 than acycloquanosine and slightly more toxic to normal cells. FIAC was about 8,000 times more active against the replication of wild-type herpes simplex virus type 1 than against a mutant strain lacking the expression of virus-specified thymidine kinase. Since FIAC appears to be preferentially phosphorylated by the viral enzyme, this is probably responsible, at least in part, for the selectivity of its antiviral actions. Although FIAC appears to be an arabinosylcytosine analog, its antiviral activity was not reversed by deoxycytidine. The minimal cytotoxicity exhibited by FIAC for normal cells, however, was reversed by equimolar concentrations of deoxycytidine. Thymidine, which reversed the antiviral activity, was effective only when used in great excess.

2'-fluoro-5-iodo-aracytosine, a potent and selective anti-herpesvirus agent.

PubMed Central

Lopez, C; Watanabe, K A; Fox, J J

1980-01-01

A newly synthesized pyrimidine analog, 2'-fluoro-5-iodo-aracytosine (FIAC), suppressed by 90% the replication of various strains of herpes simplex virus types 1 and 2 at concentrations of 0.0025 to 0.0126 microM. Cytotoxicity was minimal, as determined by trypan blue dye exclusion with norman Vero, WI-38, and NC-37 cell proliferation; the 50% inhibitory dose was 4 to 10 microM in a 4-day assay. When compared with other antiviral drugs, FIAC was active at much lower concentrations than arabinosylcytosine, iododeoxyuridine, and arabinosyladenine. It was slightly more active against herpes simplex virus type 1 than acycloquanosine and slightly more toxic to normal cells. FIAC was about 8,000 times more active against the replication of wild-type herpes simplex virus type 1 than against a mutant strain lacking the expression of virus-specified thymidine kinase. Since FIAC appears to be preferentially phosphorylated by the viral enzyme, this is probably responsible, at least in part, for the selectivity of its antiviral actions. Although FIAC appears to be an arabinosylcytosine analog, its antiviral activity was not reversed by deoxycytidine. The minimal cytotoxicity exhibited by FIAC for normal cells, however, was reversed by equimolar concentrations of deoxycytidine. Thymidine, which reversed the antiviral activity, was effective only when used in great excess. PMID:6249196

Flavocoxid exerts a potent antiviral effect against hepatitis B virus.

PubMed

Pollicino, Teresa; Musolino, Cristina; Irrera, Natasha; Bitto, Alessandra; Lombardo, Daniele; Timmoneri, Martina; Minutoli, Letteria; Raimondo, Giovanni; Squadrito, Giovanni; Squadrito, Francesco; Altavilla, Domenica

2018-01-01

Flavocoxid is a proprietary blend of two flavonoids, baicalin and catechin, and recent evidence has shown that bioflavonoids may exert antiviral activities. The potential antiviral activity of Flavocoxid against hepatitis B virus (HBV) was evaluated. Additionally, it was investigated if Flavocoxid used in combination with Entecavir could potentiate its anti-HBV activity. Hepatoma cells replicating HBV were treated with Flavocoxid, or Entecavir alone or in combination for up to 5 days. Viral replicative intermediates, transcripts, and cccDNA levels were evaluated in HBV-replicating cells by real-time PCR, Southern and Northern blotting. Expression profiling was performed using TaqMan low-density arrays. Flavocoxid treatment induced a reduction of HBV replicative intermediates, the amount of transcripts, and HBsAg levels. Flavocoxid and Entecavir combination therapy further decreased the amount of HBV replicative intermediates, compared to Flavocoxid alone. Importantly, Flavocoxid alone or in combination with Entecavir also induced a reduction of cccDNA. Gene-expression analysis showed that Flavocoxid activates type I IFNs-signaling and dampens the HBV-induced inflammatory response. Flavocoxid inhibits HBV replication by targeting multiple steps of viral life cycle. These results indicate that the antiviral activity of Entecavir is potentiated by Flavocoxid, suggesting that this medical food might be considered as an adjuvant for anti-HBV therapy.

Novel Role for Protein Inhibitor of Activated STAT 4 (PIAS4) in the Restriction of Herpes Simplex Virus 1 by the Cellular Intrinsic Antiviral Immune Response.

PubMed

Conn, Kristen L; Wasson, Peter; McFarlane, Steven; Tong, Lily; Brown, James R; Grant, Kyle G; Domingues, Patricia; Boutell, Chris

2016-05-01

Small ubiquitin-like modifier (SUMO) is used by the intrinsic antiviral immune response to restrict viral pathogens, such as herpes simplex virus 1 (HSV-1). Despite characterization of the host factors that rely on SUMOylation to exert their antiviral effects, the enzymes that mediate these SUMOylation events remain to be defined. We show that unconjugated SUMO levels are largely maintained throughout infection regardless of the presence of ICP0, the HSV-1 SUMO-targeted ubiquitin ligase. Moreover, in the absence of ICP0, high-molecular-weight SUMO-conjugated proteins do not accumulate if HSV-1 DNA does not replicate. These data highlight the continued importance for SUMO signaling throughout infection. We show that the SUMO ligase protein inhibitor of activated STAT 4 (PIAS4) is upregulated during HSV-1 infection and localizes to nuclear domains that contain viral DNA. PIAS4 is recruited to sites associated with HSV-1 genome entry through SUMO interaction motif (SIM)-dependent mechanisms that are destabilized by ICP0. In contrast, PIAS4 accumulates in replication compartments through SIM-independent mechanisms irrespective of ICP0 expression. Depletion of PIAS4 enhances the replication of ICP0-null mutant HSV-1, which is susceptible to restriction by the intrinsic antiviral immune response. The mechanisms of PIAS4-mediated restriction are synergistic with the restriction mechanisms of a characterized intrinsic antiviral factor, promyelocytic leukemia protein, and are antagonized by ICP0. We provide the first evidence that PIAS4 is an intrinsic antiviral factor. This novel role for PIAS4 in intrinsic antiviral immunity contrasts with the known roles of PIAS proteins as suppressors of innate immunity. Posttranslational modifications with small ubiquitin-like modifier (SUMO) proteins regulate multiple aspects of host immunity and viral replication. The protein inhibitor of activated STAT (PIAS) family of SUMO ligases is predominantly associated with the suppression of innate immune signaling. We now identify a unique and contrasting role for PIAS proteins as positive regulators of the intrinsic antiviral immune response to herpes simplex virus 1 (HSV-1) infection. We show that PIAS4 relocalizes to nuclear domains that contain viral DNA throughout infection. Depletion of PIAS4, either alone or in combination with the intrinsic antiviral factor promyelocytic leukemia protein, significantly impairs the intrinsic antiviral immune response to HSV-1 infection. Our data reveal a novel and dynamic role for PIAS4 in the cellular-mediated restriction of herpesviruses and establish a new functional role for the PIAS family of SUMO ligases in the intrinsic antiviral immune response to DNA virus infection. Copyright © 2016 Conn et al.

Novel Role for Protein Inhibitor of Activated STAT 4 (PIAS4) in the Restriction of Herpes Simplex Virus 1 by the Cellular Intrinsic Antiviral Immune Response

PubMed Central

Conn, Kristen L.; Wasson, Peter; McFarlane, Steven; Tong, Lily; Brown, James R.; Grant, Kyle G.; Domingues, Patricia

2016-01-01

ABSTRACT Small ubiquitin-like modifier (SUMO) is used by the intrinsic antiviral immune response to restrict viral pathogens, such as herpes simplex virus 1 (HSV-1). Despite characterization of the host factors that rely on SUMOylation to exert their antiviral effects, the enzymes that mediate these SUMOylation events remain to be defined. We show that unconjugated SUMO levels are largely maintained throughout infection regardless of the presence of ICP0, the HSV-1 SUMO-targeted ubiquitin ligase. Moreover, in the absence of ICP0, high-molecular-weight SUMO-conjugated proteins do not accumulate if HSV-1 DNA does not replicate. These data highlight the continued importance for SUMO signaling throughout infection. We show that the SUMO ligase protein inhibitor of activated STAT 4 (PIAS4) is upregulated during HSV-1 infection and localizes to nuclear domains that contain viral DNA. PIAS4 is recruited to sites associated with HSV-1 genome entry through SUMO interaction motif (SIM)-dependent mechanisms that are destabilized by ICP0. In contrast, PIAS4 accumulates in replication compartments through SIM-independent mechanisms irrespective of ICP0 expression. Depletion of PIAS4 enhances the replication of ICP0-null mutant HSV-1, which is susceptible to restriction by the intrinsic antiviral immune response. The mechanisms of PIAS4-mediated restriction are synergistic with the restriction mechanisms of a characterized intrinsic antiviral factor, promyelocytic leukemia protein, and are antagonized by ICP0. We provide the first evidence that PIAS4 is an intrinsic antiviral factor. This novel role for PIAS4 in intrinsic antiviral immunity contrasts with the known roles of PIAS proteins as suppressors of innate immunity. IMPORTANCE Posttranslational modifications with small ubiquitin-like modifier (SUMO) proteins regulate multiple aspects of host immunity and viral replication. The protein inhibitor of activated STAT (PIAS) family of SUMO ligases is predominantly associated with the suppression of innate immune signaling. We now identify a unique and contrasting role for PIAS proteins as positive regulators of the intrinsic antiviral immune response to herpes simplex virus 1 (HSV-1) infection. We show that PIAS4 relocalizes to nuclear domains that contain viral DNA throughout infection. Depletion of PIAS4, either alone or in combination with the intrinsic antiviral factor promyelocytic leukemia protein, significantly impairs the intrinsic antiviral immune response to HSV-1 infection. Our data reveal a novel and dynamic role for PIAS4 in the cellular-mediated restriction of herpesviruses and establish a new functional role for the PIAS family of SUMO ligases in the intrinsic antiviral immune response to DNA virus infection. PMID:26937035

Nucleic acid-induced antiviral immunity in invertebrates: an evolutionary perspective.

PubMed

Wang, Pei-Hui; Weng, Shao-Ping; He, Jian-Guo

2015-02-01

Nucleic acids derived from viral pathogens are typical pathogen associated molecular patterns (PAMPs). In mammals, the recognition of viral nucleic acids by pattern recognition receptors (PRRs), which include Toll-like receptors (TLRs) and retinoic acid-inducible gene (RIG)-I-like receptors (RLRs), induces the release of inflammatory cytokines and type I interferons (IFNs) through the activation of nuclear factor κB (NF-κB) and interferon regulatory factor (IRF) 3/7 pathways, triggering the host antiviral state. However, whether nucleic acids can induce similar antiviral immunity in invertebrates remains ambiguous. Several studies have reported that nucleic acid mimics, especially dsRNA mimic poly(I:C), can strongly induce non-specific antiviral immune responses in insects, shrimp, and oyster. This behavior shows multiple similarities to the hallmarks of mammalian IFN responses. In this review, we highlight the current understanding of nucleic acid-induced antiviral immunity in invertebrates. We also discuss the potential recognition and regulatory mechanisms that confer non-specific antiviral immunity on invertebrate hosts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Research in drug development against viral diseases of military importance (biological testing). Volume 2. Final report, 15 November 1985-31 January 1991

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

Shannon, W.M.; Arnett, G.; Brazier, A.D.

1991-03-01

The purpose of this program is to evaluate the efficacy of candidate antiviral compounds against a spectrum of viruses of military importance. This program involves (a) primary testing of chemical compounds and natural products for antiviral efficacy in vitro using standard CPE-inhibition assays, (b) primary testing of compounds for antiviral efficacy in vivo in animal model systems, and (c) secondary evaluation of the active candidate antiviral compounds. The target viruses for in vitro testing are Vaccinia Virus (VV), Adenovirus (AD2), Vesicular Stomatitis Virus (VSV), Punta Toro Virus (PT), Sandfly fever Virus (SF), Yellow Fever Virus (YF), Venezuelan Equine Encephalomyelitis Virusmore » (VE), Japanese Encephalitis Virus, Pichinde Virus (PIC), Hantaan Virus (HTN), and Human Immunodeficiency Virus (HIV). The in vivo systems are Pichinde Virus infection of hamsters, Venezuelan Equine Encephalomyelitis Virus, Japanese Encephalitis Virus and Vaccinia virus infections of mice. Approximately 10,000 compounds have been received for in vitro evaluation and over 66,000 assays have been performed on this contract. Compounds have been identified in nearly all virus systems that have confirmed antiviral activity equal or exceeding that of the various positive control compounds (ribavirin, selenazofurin, carbocyclic-3-aza-adenosine, adenosine dialdehyde, Ara-A, ddC and AZT). Many of these compounds represent potent and selective new antiviral agents.« less

The Race To Find Antivirals for Zika Virus

PubMed Central

2017-01-01

ABSTRACT Zika virus (ZIKV), a flavivirus transmitted by mosquitoes, was an almost neglected pathogen until its introduction in the Americas in 2015 and its subsequent explosive spread throughout the continent, where it has infected millions of people. The virus has caused social and sanitary alarm, mainly due to its association with severe neurological disorders (Guillain-Barré syndrome and microcephaly in fetuses and newborns). Nowadays, no specific antiviral therapy against ZIKV is available. However, during the past months, a great effort has been made to search for antiviral candidates using different approaches and methodologies, ranging from testing specific compounds with known antiviral activity to the screening of libraries with hundreds of bioactive molecules. The identified antiviral candidates include drugs targeting viral components as well as cellular ones. Here, an updated review of what has been done in this line is presented. PMID:28348160

Heparin (GAG-hed) inhibits LCR activity of human papillomavirus type 18 by decreasing AP1 binding.

PubMed

Villanueva, Rita; Morales-Peza, Néstor; Castelán-Sánchez, Irma; García-Villa, Enrique; Tapia, Rocio; Cid-Arregui, Angel; García-Carrancá, Alejandro; López-Bayghen, Esther; Gariglio, Patricio

2006-08-31

High risk HPVs are causative agents of anogenital cancers. Viral E6 and E7 genes are continuously expressed and are largely responsible for the oncogenic activity of these viruses. Transcription of the E6 and E7 genes is controlled by the viral Long Control Region (LCR), plus several cellular transcription factors including AP1 and the viral protein E2. Within the LCR, the binding and activity of the transcription factor AP1 represents a key regulatory event in maintaining E6/E7 gene expression and uncontrolled cell proliferation. Glycosaminoglycans (GAGs), such as heparin, can inhibit tumour growth; they have also shown antiviral effects and inhibition of AP1 transcriptional activity. The purpose of this study was to test the heparinoid GAG-hed, as a possible antiviral and antitumoral agent in an HPV18 positive HeLa cell line. Using in vivo and in vitro approaches we tested GAG-hed effects on HeLa tumour cell growth, cell proliferation and on the expression of HPV18 E6/E7 oncogenes. GAG-hed effects on AP1 binding to HPV18-LCR-DNA were tested by EMSA. We were able to record the antitumoral effect of GAG-hed in vivo by using as a model tumours induced by injection of HeLa cells into athymic female mice. The antiviral effect of GAG-hed resulted in the inhibition of LCR activity and, consequently, the inhibition of E6 and E7 transcription. A specific diminishing of cell proliferation rates was observed in HeLa but not in HPV-free colorectal adenocarcinoma cells. Treated HeLa cells did not undergo apoptosis but the percentage of cells in G2/M phase of the cell cycle was increased. We also detected that GAG-hed prevents the binding of the transcription factor AP1 to the LCR. Direct interaction of GAG-hed with the components of the AP1 complex and subsequent interference with its ability to correctly bind specific sites within the viral LCR may contribute to the inhibition of E6/E7 transcription and cell proliferation. Our data suggest that GAG-hed could have antitumoral and antiviral activity mainly by inhibiting AP1 binding to the HPV18-LCR.

The factors associated with longitudinal changes in liver stiffness in patients with chronic hepatitis B

PubMed Central

Yo, In Ku; Park, Jin Woong; Lee, Jong Joon; Lee, Jung Hyun; Won, In Sik; Na, Sun Young; Jang, Pil Kyu; Park, Pyung Hwa; Choi, Duck Joo; Kim, Yun Soo; Kim, Ju Hyun

2015-01-01

Background/Aims Liver stiffness (LS) as assessed by transient elastography (TE) can change longitudinally in patients with chronic hepatitis B (CHB). The aim of this study was to identify the factors that improve LS. Methods Between April 2007 and December 2012, 151 patients with CHB who underwent two TE procedures with an interval of about 2 years were enrolled. Ninety-six of the 151 patients were treated with nucleos(t)ide analogues [the antiviral therapy (+) group], while the remaining 55 patients were not [the antiviral therapy (-) group]. The two groups of patients were stratified according to whether they exhibited an improvement or a deterioration in LS during the study period (defined as an LS change of ≤0 or >0 kPa, respectively, over a 1-year period), and their data were compared. Results No differences were observed between the antiviral therapy (+) and (-) groups with respect to either their clinical characteristics or their initial LS. The observed LS improvement was significantly greater in the antiviral therapy (+) group than in the antiviral therapy (-) group (-3.0 vs. 0.98 kPa, P=0.011). In the antiviral therapy (+) group, the initial LS was higher in the LS improvement group (n=63) than in the LS deterioration group (n=33; 7.9 vs. 4.8 kPa, P<0.001). However, there were no differences in any other clinical characteristic. In the antiviral therapy (-) group, the initial LS was also higher in the LS improvement group (n=29) than in the LS deterioration group (n=26; 8.3 vs. 6.5 kPa, P=0.021), with no differences in any other clinical characteristic. Conclusions A higher initial LS was the only factor associated with LS improvement in patients with CHB in this study. PMID:25834800

The factors associated with longitudinal changes in liver stiffness in patients with chronic hepatitis B.

PubMed

Yo, In Ku; Kwon, Oh Sang; Park, Jin Woong; Lee, Jong Joon; Lee, Jung Hyun; Won, In Sik; Na, Sun Young; Jang, Pil Kyu; Park, Pyung Hwa; Choi, Duck Joo; Kim, Yun Soo; Kim, Ju Hyun

2015-03-01

Liver stiffness (LS) as assessed by transient elastography (TE) can change longitudinally in patients with chronic hepatitis B (CHB). The aim of this study was to identify the factors that improve LS. Between April 2007 and December 2012, 151 patients with CHB who underwent two TE procedures with an interval of about 2 years were enrolled. Ninety-six of the 151 patients were treated with nucleos(t)ide analogues [the antiviral therapy (+) group], while the remaining 55 patients were not [the antiviral therapy (-) group]. The two groups of patients were stratified according to whether they exhibited an improvement or a deterioration in LS during the study period (defined as an LS change of ≤0 or >0 kPa, respectively, over a 1-year period), and their data were compared. No differences were observed between the antiviral therapy (+) and (-) groups with respect to either their clinical characteristics or their initial LS. The observed LS improvement was significantly greater in the antiviral therapy (+) group than in the antiviral therapy (-) group (-3.0 vs. 0.98 kPa, P=0.011). In the antiviral therapy (+) group, the initial LS was higher in the LS improvement group (n=63) than in the LS deterioration group (n=33; 7.9 vs. 4.8 kPa, P<0.001). However, there were no differences in any other clinical characteristic. In the antiviral therapy (-) group, the initial LS was also higher in the LS improvement group (n=29) than in the LS deterioration group (n=26; 8.3 vs. 6.5 kPa, P=0.021), with no differences in any other clinical characteristic. A higher initial LS was the only factor associated with LS improvement in patients with CHB in this study.

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

Khachatoorian, Ronik, E-mail: RnKhch@ucla.edu; Molecular Biology Institute, David Geffen School of Medicine at University of California, Los Angeles, California, CA; Arumugaswami, Vaithilingaraja, E-mail: VArumugaswami@mednet.ucla.edu

We have previously demonstrated that quercetin, a bioflavonoid, blocks hepatitis C virus (HCV) proliferation by inhibiting NS5A-driven internal ribosomal entry site (IRES)-mediated translation of the viral genome. Here, we investigate the mechanisms of antiviral activity of quercetin and six additional bioflavonoids. We demonstrate that catechin, naringenin, and quercetin possess significant antiviral activity, with no associated cytotoxicity. Infectious virion secretion was not significantly altered by these bioflavonoids. Catechin and naringenin demonstrated stronger inhibition of infectious virion assembly compared to quercetin. Quercetin markedly blocked viral translation whereas catechin and naringenin demonstrated mild activity. Similarly quercetin completely blocked NS5A-augmented IRES-mediated translation in anmore » IRES reporter assay, whereas catechin and naringenin had only a mild effect. Moreover, quercetin differentially inhibited HSP70 induction compared to catechin and naringenin. Thus, the antiviral activity of these bioflavonoids is mediated through different mechanisms. Therefore combination of these bioflavonoids may act synergistically against HCV.« less

Virantmycin, a new antiviral antibiotic produced by a strain of Streptomyces.

PubMed

Nakagawa, A; Iwai, Y; Hashimoto, H; Miyazaki, N; Oiwa, R; Takahashi, Y; Hirano, A; Shibukawa, N; Kojima, Y; Omura, S

1981-11-01

Virantmycin, a novel chlorine-containing antiviral antibiotic, has been isolated from Streptomyces nitrosporeus No. AM-2722. The active substance in culture broth is isolated as colorless needles by solvent extraction followed by high performance liquid chromatography on silicic acid. The molecular formula is C19H26NO3Cl (molecular weight 351) from the elemental analysis and mass spectrum. The antibiotic possesses antifungal activity and potent inhibitory activity against various RNA and DNA viruses.

TRIM56 Is an Essential Component of the TLR3 Antiviral Signaling Pathway*

PubMed Central

Shen, Yang; Li, Nan L.; Wang, Jie; Liu, Baoming; Lester, Sandra; Li, Kui

2012-01-01

Members of the tripartite motif (TRIM) proteins are being recognized as important regulators of host innate immunity. However, specific TRIMs that contribute to TLR3-mediated antiviral defense have not been identified. We show here that TRIM56 is a positive regulator of TLR3 signaling. Overexpression of TRIM56 substantially potentiated extracellular dsRNA-induced expression of interferon (IFN)-β and interferon-stimulated genes (ISGs), while knockdown of TRIM56 greatly impaired activation of IRF3, induction of IFN-β and ISGs, and establishment of an antiviral state by TLR3 ligand and severely compromised TLR3-mediated chemokine induction following infection by hepatitis C virus. The ability to promote TLR3 signaling was independent of the E3 ubiquitin ligase activity of TRIM56. Rather, it correlated with a physical interaction between TRIM56 and TRIF. Deletion of the C-terminal portion of TRIM56 abrogated the TRIM56-TRIF interaction as well as the augmentation of TLR3-mediated IFN response. Together, our data demonstrate TRIM56 is an essential component of the TLR3 antiviral signaling pathway and reveal a novel role for TRIM56 in innate antiviral immunity. PMID:22948160

Activity of ergoferon against lethal influenza A (H3N2) virus infection in mice.

PubMed

Skarnovich, Maria A; Emelyanova, Alexandra G; Petrova, Nataliia V; Borshcheva, Alena A; Gorbunov, Evgeniy A; Mazurkov, Oleg Yu; Skarnovich, Maksim O; Tarasov, Sergey A; Shishkina, Larisa N; Epstein, Oleg I

2017-01-01

The influenza A virus accounts for serious annual viral upper respiratory tract infections. It is constantly able to modify its antigenic structure, thus evading host defence mechanisms. Moreover, currently available anti-influenza agents have a rather limited application, emphasizing the further need for new effective treatments. One of them is ergoferon, a drug containing combined polyclonal antibodies - anti-interferon gamma, anti-CD4 receptor and anti-histamine - in released-active form. The purpose of the study was to assess ergoferon antiviral efficacy in mice challenged with the A/Aichi/2/68 (H3N2) influenza virus. The virus was inoculated intranasally at a 90% lethal dose. Ergoferon was administered at 0.4 ml/day per os in a preventive and therapeutic regimen - daily for 5 days prior to and for 16 days after the challenge. The reference product, Tamiflu (oseltamivir), was used as a positive control treatment - at 20 mg/kg/day for 5 days after the challenge. Mice in the negative control group received distilled water which had been utilized for test sample preparation; untreated control animals received no treatment. Antiviral efficacy was assessed by an increase in survival rate, average life expectancy and virus titre reduction in the challenged mouse lungs. Survival rate and average life expectancy values were increased significantly in groups treated with ergoferon and Tamiflu, as compared with controls. Lung virus titres were reduced in these groups as observed on days 2 and 4 post-inoculation. Ergoferon demonstrated antiviral activity by reducing the severity and duration of the major signs of induced influenza infection.

In Vivo Antiviral Activity of 1,3-Bis(2-Chloroethyl)-1-Nitrosourea

PubMed Central

Sidwell, Robert W.; Dixon, Glen J.; Sellers, Sara M.; Schabel, Frank M.

1965-01-01

A prolongation in the lives of Swiss mice inoculated intracerebrally with lymphocytic choriomeningitis virus (LCM) was observed after treatment with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). A variety of treatment schedules, including therapy once or twice daily up to 17 days and single treatments at various times after virus inoculation, were employed. Virus titers ranging to greater than 104 were detected in the blood and brains of surviving drug-treated animals. In three comparative studies in which different treatment schedules were used, BCNU was shown to exert a protective effect approximately equal to that of methotrexate in LCM virus-infected mice. Tests were also carried out to investigate the activity of BCNU in mice experimentally infected with eastern equine encephalomyelitis (EEE) virus, western equine encephalomyelitis virus, Semliki Forest (SF) virus, herpes simplex virus, influenza virus strain PR8, vaccinia virus strain WR, Rous sarcoma virus, Friend leukemia virus (FLV), and poliovirus. Slight increases in life span were observed in the treated EEE, SF, and influenza PR8 virus-infected animals. Significant reduction in splenomegaly in FLV-infected animals treated with BCNU was demonstrated. The possible mechanisms of LCM virus inhibition by BCNU, on the basis of these and other studies, were postulated to be either specific antiviral activity or inhibition of “lethal” immune response to the LCM virus. Each of these postulates is discussed. PMID:14339266

A Kinome-Wide Small Interfering RNA Screen Identifies Proviral and Antiviral Host Factors in Severe Acute Respiratory Syndrome Coronavirus Replication, Including Double-Stranded RNA-Activated Protein Kinase and Early Secretory Pathway Proteins

PubMed Central

de Wilde, Adriaan H.; Wannee, Kazimier F.; Scholte, Florine E. M.; Goeman, Jelle J.; ten Dijke, Peter; Snijder, Eric J.

2015-01-01

ABSTRACT To identify host factors relevant for severe acute respiratory syndrome-coronavirus (SARS-CoV) replication, we performed a small interfering RNA (siRNA) library screen targeting the human kinome. Protein kinases are key regulators of many cellular functions, and the systematic knockdown of their expression should provide a broad perspective on factors and pathways promoting or antagonizing coronavirus replication. In addition to 40 proteins that promote SARS-CoV replication, our study identified 90 factors exhibiting an antiviral effect. Pathway analysis grouped subsets of these factors in specific cellular processes, including the innate immune response and the metabolism of complex lipids, which appear to play a role in SARS-CoV infection. Several factors were selected for in-depth validation in follow-up experiments. In cells depleted for the β2 subunit of the coatomer protein complex (COPB2), the strongest proviral hit, we observed reduced SARS-CoV protein expression and a >2-log reduction in virus yield. Knockdown of the COPB2-related proteins COPB1 and Golgi-specific brefeldin A-resistant guanine nucleotide exchange factor 1 (GBF1) also suggested that COPI-coated vesicles and/or the early secretory pathway are important for SARS-CoV replication. Depletion of the antiviral double-stranded RNA-activated protein kinase (PKR) enhanced virus replication in the primary screen, and validation experiments confirmed increased SARS-CoV protein expression and virus production upon PKR depletion. In addition, cyclin-dependent kinase 6 (CDK6) was identified as a novel antiviral host factor in SARS-CoV replication. The inventory of pro- and antiviral host factors and pathways described here substantiates and expands our understanding of SARS-CoV replication and may contribute to the identification of novel targets for antiviral therapy. IMPORTANCE Replication of all viruses, including SARS-CoV, depends on and is influenced by cellular pathways. Although substantial progress has been made in dissecting the coronavirus replicative cycle, our understanding of the host factors that stimulate (proviral factors) or restrict (antiviral factors) infection remains far from complete. To study the role of host proteins in SARS-CoV infection, we set out to systematically identify kinase-regulated processes that influence virus replication. Protein kinases are key regulators in signal transduction, controlling a wide variety of cellular processes, and many of them are targets of approved drugs and other compounds. Our screen identified a variety of hits and will form the basis for more detailed follow-up studies that should contribute to a better understanding of SARS-CoV replication and coronavirus-host interactions in general. The identified factors could be interesting targets for the development of host-directed antiviral therapy to treat infections with SARS-CoV or other pathogenic coronaviruses. PMID:26041291

Alpinone exhibited immunomodulatory and antiviral activities in Atlantic salmon.

PubMed

Valenzuela, Beatriz; Rodríguez, Felipe E; Modak, Brenda; Imarai, Mónica

2018-03-01

In this study, we seek to identify flavonoids able to regulate the gene expression of a group of cytokines important for the control of infections in Atlantic salmon (Salmo salar). Particularly, we studied the potential immunomodulatory effects of two flavonoids, Alpinone and Pinocembrine, which were isolated and purified from resinous exudates of Heliotropium huascoense and Heliotropium sinuatum, respectively. The transcript levels of TNF-α and IL-1 (inflammatory cytokines), IFN-γ and IL-12 (T helper 1 type cytokines), IL4/13A (Th2-type cytokine), IL-17 (Th17 type cytokine) TGF-β1 (regulatory cytokine) and IFN-α (antiviral cytokine) were quantified by qRT-PCR in kidneys of flavonoid-treated and control fish. We demonstrated that the administration of a single intramuscular dose of purified Alpinone increased the transcriptional expression of five cytokines, named TNF-α, IL-1, IFN-α, IFN-γ and TGF-β1 in treated fish compared to untreated fish. Conversely, administration of purified Pinocembrine reduced the transcriptional expression of TNF-α, IL-1 and IL-12 in the kidney of treated fish. No other changes were observed. Interestingly, Alpinone also induced in vitro antiviral effects against Infectious Salmon Anaemia virus. Results showed that Alpinone but not Pinocembrine induces the expression of cytokines, which in vertebrates are essential to control viral infections while Pinocembrine reduces pro-inflammatory cytokines. Altogether results suggest that Alpinone is a good candidate to be further tested as immunostimulant and antiviral drug. Copyright © 2017 Elsevier Ltd. All rights reserved.

Actinobacillus pleuropneumoniae culture supernatant antiviral effect against porcine reproductive and respiratory syndrome virus occurs prior to the viral genome replication and transcription through actin depolymerization.

PubMed

Hernandez Reyes, Yenney; Provost, Chantale; Traesel, Carolina Kist; Jacques, Mario; Gagnon, Carl A

2018-02-01

Recently, the strong antiviral activity of an Actinobacillus pleuropneumoniae (App) culture supernatant against porcine reproductive and respiratory syndrome virus (PRRSV) was discovered. Following this finding, the objective of the present study was to understand how the App culture supernatant inhibits PRRSV replication in its natural targeted host cells, i.e. porcine alveolar macrophages (PAMs). Several assays were conducted with App culture supernatant-treated PRRSV-infected cell lines, such as PAM, St-Jude porcine lung and MARC-145 cells. RT-qPCR assays were used to determine the expression levels of type I and II IFN mRNAs, viral genomic (gRNA) and sub-genomic RNAs (sgRNAs). Proteomic, Western blot and immunofluorescence assays were conducted to determine the involvement of actin filaments in the App culture supernatant antiviral effect.Results/Key findings. Type I and II IFN mRNA expressions were not upregulated by the App culture supernatant. Time courses of gRNA and sgRNA expression levels demonstrated that the App culture supernatant inhibits PRRSV infection before the first viral transcription cycle. Western blot experiments confirmed an increase in the expression of cofilin (actin cytoskeleton dynamics regulator) and immunofluorescence also demonstrated a significant decrease of actin filaments in App culture supernatant-treated PRRSV-infected PAM cells. App culture supernatant antiviral activity was also demonstrated against other PRRSV strains of genotypes I and II. App culture supernatant antiviral effect against PRRSV takes place early during PRRSV infection. Results suggest that App culture supernatant antiviral effect may take place via the activation of cofilin, which induces actin depolymerization and subsequently, probably affects PRRSV endocytosis. Other experiments are needed to fully validate this latest hypothesis.

Fusion of Protegrin-1 and Plectasin to MAP30 Shows Significant Inhibition Activity against Dengue Virus Replication

PubMed Central

Rothan, Hussin A.; Bahrani, Hirbod; Mohamed, Zulqarnain; Abd Rahman, Noorsaadah; Yusof, Rohana

2014-01-01

Dengue virus (DENV) broadly disseminates in tropical and sub-tropical countries and there are no vaccine or anti-dengue drugs available. DENV outbreaks cause serious economic burden due to infection complications that requires special medical care and hospitalization. This study presents a new strategy for inexpensive production of anti-DENV peptide-fusion protein to prevent and/or treat DENV infection. Antiviral cationic peptides protegrin-1 (PG1) and plectasin (PLSN) were fused with MAP30 protein to produce recombinant antiviral peptide-fusion protein (PG1-MAP30-PLSN) as inclusion bodies in E. coli. High yield production of PG1-MAP30-PLSN protein was achieved by solubilization of inclusion bodies in alkaline buffer followed by the application of appropriate refolding techniques. Antiviral PG1-MAP30-PLSN protein considerably inhibited DENV protease (NS2B-NS3pro) with half-maximal inhibitory concentration (IC50) 0.5±0.1 μM. The real-time proliferation assay (RTCA) and the end-point proliferation assay (MTT assay) showed that the maximal-nontoxic dose of the peptide-fusion protein against Vero cells is approximately 0.67±0.2 μM. The cell-based assays showed considerable inhibition of the peptide-fusion protein against binding and proliferating stages of DENV2 into the target cells. The peptide-fusion protein protected DENV2-challeged mice with 100% of survival at the dose of 50 mg/kg. In conclusion, producing recombinant antiviral peptide-fusion protein by combining short antiviral peptide with a central protein owning similar activity could be useful to minimize the overall cost of short peptide production and take advantage of its synergistic antiviral activities. PMID:24722532

MDA5 and LGP2: Accomplices and Antagonists of Antiviral Signal Transduction

PubMed Central

Rodriguez, Kenny R.; Bruns, Annie M.

2014-01-01

Mammalian cells have the ability to recognize virus infection and mount a powerful antiviral transcriptional response that provides an initial barrier to replication and impacts both innate and adaptive immune responses. Retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) proteins mediate intracellular virus recognition and are activated by viral RNA ligands to induce antiviral signal transduction. While the mechanisms of RIG-I regulation are already well understood, less is known about the more enigmatic melanoma differentiation-associated 5 (MDA5) and laboratory of genetics and physiology 2 (LGP2). Emerging evidence suggests that these two RLRs are intimately associated as both accomplices and antagonists of antiviral signal transduction. PMID:24850739

Antiviral immunity following smallpox virus infection: a case-control study.

PubMed

Hammarlund, Erika; Lewis, Matthew W; Hanifin, Jon M; Mori, Motomi; Koudelka, Caroline W; Slifka, Mark K

2010-12-01

Outbreaks of smallpox (i.e., caused by variola virus) resulted in up to 30% mortality, but those who survived smallpox infection were regarded as immune for life. Early studies described the levels of neutralizing antibodies induced after infection, but smallpox was eradicated before contemporary methods for quantifying T-cell memory were developed. To better understand the levels and duration of immunity after smallpox infection, we performed a case-control study comparing antiviral CD4(+) and CD8(+) T-cell responses and neutralizing antibody levels of 24 smallpox survivors with the antiviral immunity observed in 60 smallpox-vaccinated (i.e., vaccinia virus-immune) control subjects. We found that the duration of immunity following smallpox infection was remarkably similar to that observed after smallpox vaccination, with antiviral T-cell responses that declined slowly over time and antiviral antibody responses that remained stable for decades after recovery from infection. These results indicate that severe, potentially life-threatening disease is not required for the development of sustainable long-term immunity. This study shows that the levels of immunity induced following smallpox vaccination are comparable in magnitude to that achieved through natural variola virus infection, and this may explain the notable success of vaccination in eradicating smallpox, one of the world's most lethal diseases.

Antiviral Immunity following Smallpox Virus Infection: a Case-Control Study▿

PubMed Central

Hammarlund, Erika; Lewis, Matthew W.; Hanifin, Jon M.; Mori, Motomi; Koudelka, Caroline W.; Slifka, Mark K.

2010-01-01

Outbreaks of smallpox (i.e., caused by variola virus) resulted in up to 30% mortality, but those who survived smallpox infection were regarded as immune for life. Early studies described the levels of neutralizing antibodies induced after infection, but smallpox was eradicated before contemporary methods for quantifying T-cell memory were developed. To better understand the levels and duration of immunity after smallpox infection, we performed a case-control study comparing antiviral CD4+ and CD8+ T-cell responses and neutralizing antibody levels of 24 smallpox survivors with the antiviral immunity observed in 60 smallpox-vaccinated (i.e., vaccinia virus-immune) control subjects. We found that the duration of immunity following smallpox infection was remarkably similar to that observed after smallpox vaccination, with antiviral T-cell responses that declined slowly over time and antiviral antibody responses that remained stable for decades after recovery from infection. These results indicate that severe, potentially life-threatening disease is not required for the development of sustainable long-term immunity. This study shows that the levels of immunity induced following smallpox vaccination are comparable in magnitude to that achieved through natural variola virus infection, and this may explain the notable success of vaccination in eradicating smallpox, one of the world's most lethal diseases. PMID:20926574

Scientific report: highlights of 25th ICAR, 16-19 April 2012, Sapporo, Japan.

PubMed

Hodge, Anthony Vere

2012-09-25

Each year, the International Society for Antiviral Research (ISAR) organises a conference covering many differing aspects of antiviral research. The 25th International Conference on Antiviral Research (ICAR) was held in Japan. This special anniversary meeting was co-sponsored by the Japanese Association for Antiviral Therapy.This Workshop Report contains summaries of the four major lectures and each of the invited presentations in the Clinical symposium and in the three mini-symposia. Of the many interesting contributor presentations, there are brief summaries of a small selection of these. This report concludes with a few personal comments and observations.A brief summary of this report is included within the ISAR News published in this issue of AVCC.

TRIM25 RING-finger E3 ubiquitin ligase is essential for RIG-I-mediated antiviral activity.

PubMed

Gack, Michaela U; Shin, Young C; Joo, Chul-Hyun; Urano, Tomohiko; Liang, Chengyu; Sun, Lijun; Takeuchi, Osamu; Akira, Shizuo; Chen, Zhijian; Inoue, Satoshi; Jung, Jae U

2007-04-19

Retinoic-acid-inducible gene-I (RIG-I; also called DDX58) is a cytosolic viral RNA receptor that interacts with MAVS (also called VISA, IPS-1 or Cardif) to induce type I interferon-mediated host protective innate immunity against viral infection. Furthermore, members of the tripartite motif (TRIM) protein family, which contain a cluster of a RING-finger domain, a B box/coiled-coil domain and a SPRY domain, are involved in various cellular processes, including cell proliferation and antiviral activity. Here we report that the amino-terminal caspase recruitment domains (CARDs) of RIG-I undergo robust ubiquitination induced by TRIM25 in mammalian cells. The carboxy-terminal SPRY domain of TRIM25 interacts with the N-terminal CARDs of RIG-I; this interaction effectively delivers the Lys 63-linked ubiquitin moiety to the N-terminal CARDs of RIG-I, resulting in a marked increase in RIG-I downstream signalling activity. The Lys 172 residue of RIG-I is critical for efficient TRIM25-mediated ubiquitination and for MAVS binding, as well as the ability of RIG-I to induce antiviral signal transduction. Furthermore, gene targeting demonstrates that TRIM25 is essential not only for RIG-I ubiquitination but also for RIG-I-mediated interferon- production and antiviral activity in response to RNA virus infection. Thus, we demonstrate that TRIM25 E3 ubiquitin ligase induces the Lys 63-linked ubiquitination of RIG-I, which is crucial for the cytosolic RIG-I signalling pathway to elicit host antiviral innate immunity.

A new class of dual-targeted antivirals: monophosphorylated acyclovir prodrug derivatives suppress both human immunodeficiency virus type 1 and herpes simplex virus type 2.

PubMed

Vanpouille, Christophe; Lisco, Andrea; Derudas, Marco; Saba, Elisa; Grivel, Jean-Charles; Brichacek, Beda; Scrimieri, Francesca; Schinazi, Raymond; Schols, Dominique; McGuigan, Christopher; Balzarini, Jan; Margolis, Leonid

2010-02-15

Human immunodeficiency virus type 1 (HIV-1) and herpes simplex virus type 2 (HSV-2) are responsible for 2 intersecting epidemics in which the disease caused by 1 virus facilitates the transmission of and pathogenesis by the other. Therefore, suppression of one virus infection will affect the other. Acyclovir, a common antiherpetic drug, was shown to directly suppress both viruses in coinfected tissues. However, both antiviral activities of acyclovir are dependent on phosphorylation by the nucleoside kinase activity of coinfecting human herpesviruses. We developed acyclovir ProTides, monophosphorylated acyclovir with the phosphate group masked by lipophilic groups to allow efficient cellular uptake, and investigated their antiviral potential in cell lines and in human tissues ex vivo. Acyclovir ProTides suppressed both HIV-1 and HSV-2 at median effective concentrations in the submicromolar range in ex vivo lymphoid and cervicovaginal human tissues and at 3-12 micromol/L in CD4(+) T cells. Acyclovir ProTides retained activity against acyclovir-resistant HSV-2. Acyclovir ProTides represent a new class of antivirals that suppress both HIV-1 and HSV-2 by directly and independently blocking the key replicative enzymes of both viruses. Further optimization of such compounds may lead to double-targeted antivirals that can prevent viral transmission and treat the 2 synergistic diseases caused by HIV-1 and HSV-2. To our knowledge, the acyclovir ProTides described here represent the first example of acyclic nucleoside monophosphate prodrugs being active against HIV-1.

Iminosugars Inhibit Dengue Virus Production via Inhibition of ER Alpha-Glucosidases--Not Glycolipid Processing Enzymes.

PubMed

Sayce, Andrew C; Alonzi, Dominic S; Killingbeck, Sarah S; Tyrrell, Beatrice E; Hill, Michelle L; Caputo, Alessandro T; Iwaki, Ren; Kinami, Kyoko; Ide, Daisuke; Kiappes, J L; Beatty, P Robert; Kato, Atsushi; Harris, Eva; Dwek, Raymond A; Miller, Joanna L; Zitzmann, Nicole

2016-03-01

It has long been thought that iminosugar antiviral activity is a function of inhibition of endoplasmic reticulum-resident α-glucosidases, and on this basis, many iminosugars have been investigated as therapeutic agents for treatment of infection by a diverse spectrum of viruses, including dengue virus (DENV). However, iminosugars are glycomimetics possessing a nitrogen atom in place of the endocyclic oxygen atom, and the ubiquity of glycans in host metabolism suggests that multiple pathways can be targeted via iminosugar treatment. Successful treatment of patients with glycolipid processing defects using iminosugars highlights the clinical exploitation of iminosugar inhibition of enzymes other than ER α-glucosidases. Evidence correlating antiviral activity with successful inhibition of ER glucosidases together with the exclusion of alternative mechanisms of action of iminosugars in the context of DENV infection is limited. Celgosivir, a bicyclic iminosugar evaluated in phase Ib clinical trials as a therapeutic for the treatment of DENV infection, was confirmed to be antiviral in a lethal mouse model of antibody-enhanced DENV infection. In this study we provide the first evidence of the antiviral activity of celgosivir in primary human macrophages in vitro, in which it inhibits DENV secretion with an EC50 of 5 μM. We further demonstrate that monocyclic glucose-mimicking iminosugars inhibit isolated glycoprotein and glycolipid processing enzymes and that this inhibition also occurs in primary cells treated with these drugs. By comparison to bicyclic glucose-mimicking iminosugars which inhibit glycoprotein processing but do not inhibit glycolipid processing and galactose-mimicking iminosugars which do not inhibit glycoprotein processing but do inhibit glycolipid processing, we demonstrate that inhibition of endoplasmic reticulum-resident α-glucosidases, not glycolipid processing, is responsible for iminosugar antiviral activity against DENV. Our data suggest that inhibition of ER α-glucosidases prevents release of virus and is the primary antiviral mechanism of action of iminosugars against DENV.

RIOK3 Is an Adaptor Protein Required for IRF3-Mediated Antiviral Type I Interferon Production

PubMed Central

Feng, Jun; De Jesus, Paul D.; Su, Victoria; Han, Stephanie; Gong, Danyang; Wu, Nicholas C.; Tian, Yuan; Li, Xudong; Wu, Ting-Ting; Chanda, Sumit K.

2014-01-01

ABSTRACT Detection of cytosolic nucleic acids by pattern recognition receptors leads to the induction of type I interferons (IFNs) and elicits the innate immune response. We report here the identification of RIOK3 as a novel adaptor protein that is essential for the cytosolic nucleic acid-induced type I IFN production and for the antiviral response to gammaherpesvirus through two independent kinome-wide RNA interference screens. RIOK3 knockdown blocks both cytosolic double-stranded B-form DNA and double-stranded RNA-induced IRF3 activation and IFN-β production. In contrast, the overexpression of RIOK3 activates IRF3 and induces IFN-β. RIOK3 functions downstream of TBK1 and upstream of IRF3 activation. Furthermore, RIOK3 physically interacts with both IRF3 and TBK1 and is necessary for the interaction between TBK1 and IRF3. In addition, global transcriptome analysis shows that the expression of many gene involved antiviral responses is dependent on RIOK3. Thus, knockdown of RIOK3 inhibits cellular antiviral responses against both DNA and RNA viruses (herpesvirus and influenza A virus). Our data suggest that RIOK3 plays a critical role in the antiviral type I IFN pathway by bridging TBK1 and IRF3. IMPORTANCE The innate immune response, such as the production of type I interferons, acts as the first line of defense, limiting infectious pathogens directly and shaping the adaptive immune response. In this study, we identified RIOK3 as a novel regulator of the antiviral type I interferon pathway. Specifically, we found that RIOK3 physically interacts with TBK1 and IRF3 and bridges the functions between TBK1 and IRF3 in the activation of type I interferon pathway. The identification of a cellular kinase that plays a role the type I interferon pathway adds another level of complexity in the regulation of innate immunity and will have implications for developing novel strategies to combat viral infection. PMID:24807708

Therapeutic efficacy of the small molecule GS-5734 against Ebola virus in rhesus monkeys.

PubMed

Warren, Travis K; Jordan, Robert; Lo, Michael K; Ray, Adrian S; Mackman, Richard L; Soloveva, Veronica; Siegel, Dustin; Perron, Michel; Bannister, Roy; Hui, Hon C; Larson, Nate; Strickley, Robert; Wells, Jay; Stuthman, Kelly S; Van Tongeren, Sean A; Garza, Nicole L; Donnelly, Ginger; Shurtleff, Amy C; Retterer, Cary J; Gharaibeh, Dima; Zamani, Rouzbeh; Kenny, Tara; Eaton, Brett P; Grimes, Elizabeth; Welch, Lisa S; Gomba, Laura; Wilhelmsen, Catherine L; Nichols, Donald K; Nuss, Jonathan E; Nagle, Elyse R; Kugelman, Jeffrey R; Palacios, Gustavo; Doerffler, Edward; Neville, Sean; Carra, Ernest; Clarke, Michael O; Zhang, Lijun; Lew, Willard; Ross, Bruce; Wang, Queenie; Chun, Kwon; Wolfe, Lydia; Babusis, Darius; Park, Yeojin; Stray, Kirsten M; Trancheva, Iva; Feng, Joy Y; Barauskas, Ona; Xu, Yili; Wong, Pamela; Braun, Molly R; Flint, Mike; McMullan, Laura K; Chen, Shan-Shan; Fearns, Rachel; Swaminathan, Swami; Mayers, Douglas L; Spiropoulou, Christina F; Lee, William A; Nichol, Stuart T; Cihlar, Tomas; Bavari, Sina

2016-03-17

The most recent Ebola virus outbreak in West Africa, which was unprecedented in the number of cases and fatalities, geographic distribution, and number of nations affected, highlights the need for safe, effective, and readily available antiviral agents for treatment and prevention of acute Ebola virus (EBOV) disease (EVD) or sequelae. No antiviral therapeutics have yet received regulatory approval or demonstrated clinical efficacy. Here we report the discovery of a novel small molecule GS-5734, a monophosphoramidate prodrug of an adenosine analogue, with antiviral activity against EBOV. GS-5734 exhibits antiviral activity against multiple variants of EBOV and other filoviruses in cell-based assays. The pharmacologically active nucleoside triphosphate (NTP) is efficiently formed in multiple human cell types incubated with GS-5734 in vitro, and the NTP acts as an alternative substrate and RNA-chain terminator in primer-extension assays using a surrogate respiratory syncytial virus RNA polymerase. Intravenous administration of GS-5734 to nonhuman primates resulted in persistent NTP levels in peripheral blood mononuclear cells (half-life, 14 h) and distribution to sanctuary sites for viral replication including testes, eyes, and brain. In a rhesus monkey model of EVD, once-daily intravenous administration of 10 mg kg(-1) GS-5734 for 12 days resulted in profound suppression of EBOV replication and protected 100% of EBOV-infected animals against lethal disease, ameliorating clinical disease signs and pathophysiological markers, even when treatments were initiated three days after virus exposure when systemic viral RNA was detected in two out of six treated animals. These results show the first substantive post-exposure protection by a small-molecule antiviral compound against EBOV in nonhuman primates. The broad-spectrum antiviral activity of GS-5734 in vitro against other pathogenic RNA viruses, including filoviruses, arenaviruses, and coronaviruses, suggests the potential for wider medical use. GS-5734 is amenable to large-scale manufacturing, and clinical studies investigating the drug safety and pharmacokinetics are ongoing.

Antimicrobial, antiviral and antioxidant activities of "água-mel" from Portugal.

PubMed

Miguel, Maria G; Faleiro, Leonor; Antunes, Maria D; Aazza, Smail; Duarte, Joana; Silvério, Ana R

2013-06-01

"Água-mel" is a honey-based product produced in Portugal for ancient times. Several attributes have been reported to "água-mel" particularly in the alleviation of simple symptoms of upper respiratory tract. Samples of "água-mel" from diverse beekeepers from different regions of Portugal were studied in what concerns antimicrobial, antioxidant and antiviral properties. The amounts of phenol and brown pigment were also evaluated and correlated with the antioxidant activities. A great variability on the levels of these compounds was found among samples which were responsible for the variability detected also on the antioxidant activities, independent on the method used. Generally, antioxidant activity correlated better with brown pigments' amount than with phenols' content. The antimicrobial activity found for "água-mel" samples confirm the virtues reported by popular findings. In addition, this work also reveals the antiviral properties of "água-mel" evidenced by a decrease on the infectivity of the Qβ bacteriophage. Copyright © 2013 Elsevier Ltd. All rights reserved.

Broad and potent antiviral activity of the NAE inhibitor MLN4924.

PubMed

Le-Trilling, Vu Thuy Khanh; Megger, Dominik A; Katschinski, Benjamin; Landsberg, Christine D; Rückborn, Meike U; Tao, Sha; Krawczyk, Adalbert; Bayer, Wibke; Drexler, Ingo; Tenbusch, Matthias; Sitek, Barbara; Trilling, Mirko

2016-02-01

In terms of infected human individuals, herpesviruses range among the most successful virus families. Subclinical herpesviral infections in healthy individuals contrast with life-threatening syndromes under immunocompromising and immunoimmature conditions. Based on our finding that cytomegaloviruses interact with Cullin Roc ubiquitin ligases (CRLs) in the context of interferon antagonism, we systematically assessed viral dependency on CRLs by utilizing the drug MLN4924. CRL activity is regulated through the conjugation of Cullins with the ubiquitin-like molecule Nedd8. By inhibiting the Nedd8-activating Enzyme (NAE), MLN4924 interferes with Nedd8 conjugation and CRL activity. MLN4924 exhibited pronounced antiviral activity against mouse and human cytomegalovirus, herpes simplex virus (HSV)- 1 (including multi-drug resistant clinical isolates), HSV-2, adeno and influenza viruses. Human cytomegalovirus genome amplification was blocked at nanomolar MLN4924 concentrations. Global proteome analyses revealed that MLN4924 blocks cytomegaloviral replication despite increased IE1 amounts. Expression of dominant negative Cullins assigned this IE regulation to defined Cullin molecules and phenocopied the antiviral effect of MLN4924.

Learning from the Messengers: Innate Sensing of Viruses and Cytokine Regulation of Immunity—Clues for Treatments and Vaccines

PubMed Central

Melchjorsen, Jesper

2013-01-01

Virus infections are a major global public health concern, and only via substantial knowledge of virus pathogenesis and antiviral immune responses can we develop and improve medical treatments, and preventive and therapeutic vaccines. Innate immunity and the shaping of efficient early immune responses are essential for control of viral infections. In order to trigger an efficient antiviral defense, the host senses the invading microbe via pattern recognition receptors (PRRs), recognizing distinct conserved pathogen-associated molecular patterns (PAMPs). The innate sensing of the invading virus results in intracellular signal transduction and subsequent production of interferons (IFNs) and proinflammatory cytokines. Cytokines, including IFNs and chemokines, are vital molecules of antiviral defense regulating cell activation, differentiation of cells, and, not least, exerting direct antiviral effects. Cytokines shape and modulate the immune response and IFNs are principle antiviral mediators initiating antiviral response through induction of antiviral proteins. In the present review, I describe and discuss the current knowledge on early virus–host interactions, focusing on early recognition of virus infection and the resulting expression of type I and type III IFNs, proinflammatory cytokines, and intracellular antiviral mediators. In addition, the review elucidates how targeted stimulation of innate sensors, such as toll-like receptors (TLRs) and intracellular RNA and DNA sensors, may be used therapeutically. Moreover, I present and discuss data showing how current antimicrobial therapies, including antibiotics and antiviral medication, may interfere with, or improve, immune response. PMID:23435233

TRIM proteins: another class of viral victims.

PubMed

Munir, Muhammad

2010-04-20

TRIM (tripartite motif) proteins are a family of RING (really interesting new gene) domain-containing proteins comprising more than 70 human members, with new members still being described. In addition to their involvement in cell proliferation, differentiation, development, morphogenesis, and apoptosis, roles in immune signaling and antiviral functions are emerging. In response to viral infection, TRIM25 ubiquitinates the N terminus of the viral RNA receptor retinoic acid-inducible gene-I (RIG-I), and this modification is essential for RIG-I to interact with its downstream partner mitochondrial antiviral signaling (MAVS). TRIM25 activity thus leads to activation of the RIG-I signaling pathway, which results in type I interferon production to limit viral replication. Recently, it has been demonstrated that influenza A viruses target TRIM25 and disable its antiviral function, thereby suppressing the host interferon response. This Journal Club article highlights the emerging roles of TRIM proteins in antiviral defense mechanisms and an immune evasion strategy in which influenza viruses target a member of the TRIM family.

Chemokines cooperate with TNF to provide protective anti-viral immunity and to enhance inflammation.

PubMed

Alejo, Alí; Ruiz-Argüello, M Begoña; Pontejo, Sergio M; Fernández de Marco, María Del Mar; Saraiva, Margarida; Hernáez, Bruno; Alcamí, Antonio

2018-05-03

The role of cytokines and chemokines in anti-viral defense has been demonstrated, but their relative contribution to protective anti-viral responses in vivo is not fully understood. Cytokine response modifier D (CrmD) is a secreted receptor for TNF and lymphotoxin containing the smallpox virus-encoded chemokine receptor (SECRET) domain and is expressed by ectromelia virus, the causative agent of the smallpox-like disease mousepox. Here we show that CrmD is an essential virulence factor that controls natural killer cell activation and allows progression of fatal mousepox, and demonstrate that both SECRET and TNF binding domains are required for full CrmD activity. Vaccination with recombinant CrmD protects animals from lethal mousepox. These results indicate that a specific set of chemokines enhance the inflammatory and protective anti-viral responses mediated by TNF and lymphotoxin, and illustrate how viruses optimize anti-TNF strategies with the addition of a chemokine binding domain as soluble decoy receptors.

An antiviral RISC isolated from Tobacco rattle virus-infected plants.

PubMed

Ciomperlik, Jessica J; Omarov, Rustem T; Scholthof, Herman B

2011-03-30

The RNAi model predicts that during antiviral defense a RNA-induced silencing complex (RISC) is programmed with viral short-interfering RNAs (siRNAs) to target the cognate viral RNA for degradation. We show that infection of Nicotiana benthamiana with Tobacco rattle virus (TRV) activates an antiviral nuclease that specifically cleaves TRV RNA in vitro. In agreement with known RISC properties, the nuclease activity was inhibited by NaCl and EDTA and stimulated by divalent metal cations; a novel property was its preferential targeting of elongated RNA molecules. Intriguingly, the specificity of the TRV RISC could be reprogrammed by exogenous addition of RNA (containing siRNAs) from plants infected with an unrelated virus, resulting in a newly acquired ability of RISC to target this heterologous genome in vitro. Evidently the virus-specific nuclease complex from N. benthamiana represents a genuine RISC that functions as a readily employable and reprogrammable antiviral defense unit. Copyright © 2011 Elsevier Inc. All rights reserved.

Parallel shRNA and CRISPR-Cas9 screens enable antiviral drug target identification.

PubMed

Deans, Richard M; Morgens, David W; Ökesli, Ayşe; Pillay, Sirika; Horlbeck, Max A; Kampmann, Martin; Gilbert, Luke A; Li, Amy; Mateo, Roberto; Smith, Mark; Glenn, Jeffrey S; Carette, Jan E; Khosla, Chaitan; Bassik, Michael C

2016-05-01

Broad-spectrum antiviral drugs targeting host processes could potentially treat a wide range of viruses while reducing the likelihood of emergent resistance. Despite great promise as therapeutics, such drugs remain largely elusive. Here we used parallel genome-wide high-coverage short hairpin RNA (shRNA) and clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 screens to identify the cellular target and mechanism of action of GSK983, a potent broad-spectrum antiviral with unexplained cytotoxicity. We found that GSK983 blocked cell proliferation and dengue virus replication by inhibiting the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH). Guided by mechanistic insights from both genomic screens, we found that exogenous deoxycytidine markedly reduced GSK983 cytotoxicity but not antiviral activity, providing an attractive new approach to improve the therapeutic window of DHODH inhibitors against RNA viruses. Our results highlight the distinct advantages and limitations of each screening method for identifying drug targets, and demonstrate the utility of parallel knockdown and knockout screens for comprehensive probing of drug activity.

ECSIT bridges RIG-I-like receptors to VISA in signaling events of innate antiviral responses.

PubMed

Lei, Cao-Qi; Zhang, Yu; Li, Mi; Jiang, Li-Qun; Zhong, Bo; Kim, Yong Ho; Shu, Hong-Bing

2015-01-01

Upon binding to RNA structures from invading viruses, RIG-I and MDA5 are recruited to mitochondria to interact with VISA and initiate antiviral type I interferon (IFN) responses. How this process is mediated is less understood. In this report, we demonstrate that ECSIT is an essential scaffolding protein that mediates the association of VISA and RIG-I or MDA5. Overexpression of ECSIT potentiated virus-triggered activation of IFN-regulatory factor 3 (IRF3) and expression of IFNB1, whereas knockdown of ECSIT impaired viral infection-induced activation of IRF3 and expression of IFNB1 as well as cellular antiviral responses. Mechanistically, ECSIT was associated with VISA on mitochondria and important for bridging RIG-I and MDA5 to VISA. Our findings suggest that ECSIT mediates virus-triggered type I IFN induction by bridging RIG-I and MDA5 to the VISA complex, and provide new insights into the molecular events of innate antiviral immune responses. © 2014 S. Karger AG, Basel.

The antiviral protein Viperin suppresses T7 promoter dependent RNA synthesis-possible implications for its antiviral activity.

PubMed

Dukhovny, Anna; Shlomai, Amir; Sklan, Ella H

2018-05-25

Viperin is a multifunctional interferon-inducible broad-spectrum antiviral protein. Viperin belongs to the S-Adenosylmethionine (SAM) superfamily of enzymes known to catalyze a wide variety of radical-mediated reactions. However, the exact mechanism by which viperin exerts its functions is still unclear. Interestingly, for many RNA viruses viperin was shown to inhibit viral RNA accumulation by interacting with different viral non-structural proteins. Here, we show that viperin inhibits RNA synthesis by bacteriophage T7 polymerase in mammalian cells. This inhibition is specific and occurs at the RNA level. Viperin expression significantly reduced T7-mediated cytoplasmic RNA levels. The data showing that viperin inhibits the bacteriophage T7 polymerase supports the conservation of viperin's antiviral activity between species. These results highlight the possibility that viperin might utilize a broader mechanism of inhibition. Accordingly, our results suggest a novel mechanism involving polymerase inhibition and provides a tractable system for future mechanistic studies of viperin.

A human genome-wide loss-of-function screen identifies effective chikungunya antiviral drugs

PubMed Central

Karlas, Alexander; Berre, Stefano; Couderc, Thérèse; Varjak, Margus; Braun, Peter; Meyer, Michael; Gangneux, Nicolas; Karo-Astover, Liis; Weege, Friderike; Raftery, Martin; Schönrich, Günther; Klemm, Uwe; Wurzlbauer, Anne; Bracher, Franz; Merits, Andres; Meyer, Thomas F.; Lecuit, Marc

2016-01-01

Chikungunya virus (CHIKV) is a globally spreading alphavirus against which there is no commercially available vaccine or therapy. Here we use a genome-wide siRNA screen to identify 156 proviral and 41 antiviral host factors affecting CHIKV replication. We analyse the cellular pathways in which human proviral genes are involved and identify druggable targets. Twenty-one small-molecule inhibitors, some of which are FDA approved, targeting six proviral factors or pathways, have high antiviral activity in vitro, with low toxicity. Three identified inhibitors have prophylactic antiviral effects in mouse models of chikungunya infection. Two of them, the calmodulin inhibitor pimozide and the fatty acid synthesis inhibitor TOFA, have a therapeutic effect in vivo when combined. These results demonstrate the value of loss-of-function screening and pathway analysis for the rational identification of small molecules with therapeutic potential and pave the way for the development of new, host-directed, antiviral agents. PMID:27177310

A human genome-wide loss-of-function screen identifies effective chikungunya antiviral drugs.

PubMed

Karlas, Alexander; Berre, Stefano; Couderc, Thérèse; Varjak, Margus; Braun, Peter; Meyer, Michael; Gangneux, Nicolas; Karo-Astover, Liis; Weege, Friderike; Raftery, Martin; Schönrich, Günther; Klemm, Uwe; Wurzlbauer, Anne; Bracher, Franz; Merits, Andres; Meyer, Thomas F; Lecuit, Marc

2016-05-12

Chikungunya virus (CHIKV) is a globally spreading alphavirus against which there is no commercially available vaccine or therapy. Here we use a genome-wide siRNA screen to identify 156 proviral and 41 antiviral host factors affecting CHIKV replication. We analyse the cellular pathways in which human proviral genes are involved and identify druggable targets. Twenty-one small-molecule inhibitors, some of which are FDA approved, targeting six proviral factors or pathways, have high antiviral activity in vitro, with low toxicity. Three identified inhibitors have prophylactic antiviral effects in mouse models of chikungunya infection. Two of them, the calmodulin inhibitor pimozide and the fatty acid synthesis inhibitor TOFA, have a therapeutic effect in vivo when combined. These results demonstrate the value of loss-of-function screening and pathway analysis for the rational identification of small molecules with therapeutic potential and pave the way for the development of new, host-directed, antiviral agents.

Evolutionary genomics and HIV restriction factors.

PubMed

Pyndiah, Nitisha; Telenti, Amalio; Rausell, Antonio

2015-03-01

To provide updated insights into innate antiviral immunity and highlight prototypical evolutionary features of well characterized HIV restriction factors. Recently, a new HIV restriction factor, Myxovirus resistance 2, has been discovered and the region/residue responsible for its activity identified using an evolutionary approach. Furthermore, IFI16, an innate immunity protein known to sense several viruses, has been shown to contribute to the defense to HIV-1 by causing cell death upon sensing HIV-1 DNA. Restriction factors against HIV show characteristic signatures of positive selection. Different patterns of accelerated sequence evolution can distinguish antiviral strategies--offense or defence--as well as the level of specificity of the antiviral properties. Sequence analysis of primate orthologs of restriction factors serves to localize functional domains and sites responsible for antiviral action. We use recent discoveries to illustrate how evolutionary genomic analyses help identify new antiviral genes and their mechanisms of action.

Antiviral Potential of Algae Polysaccharides Isolated from Marine Sources: A Review.

PubMed

Ahmadi, Azin; Zorofchian Moghadamtousi, Soheil; Abubakar, Sazaly; Zandi, Keivan

2015-01-01

From food to fertilizer, algal derived products are largely employed in assorted industries, including agricultural, biomedical, food, and pharmaceutical industries. Among different chemical compositions isolated from algae, polysaccharides are the most well-established compounds, which were subjected to a variety of studies due to extensive bioactivities. Over the past few decades, the promising results for antiviral potential of algae-derived polysaccharides have advocated them as inordinate candidates for pharmaceutical research. Numerous studies have isolated various algal polysaccharides possessing antiviral activities, including carrageenan, alginate, fucan, laminaran, and naviculan. In addition, different mechanisms of action have been reported for these polysaccharides, such as inhibiting the binding or internalization of virus into the host cells or suppressing DNA replication and protein synthesis. This review strives for compiling previous antiviral studies of algae-derived polysaccharides and their mechanism of action towards their development as natural antiviral agents for future investigations.

In silico screening of small molecule libraries using the dengue virus envelope E protein has identified compounds with antiviral activity against multiple flaviviruses.

PubMed

Kampmann, Thorsten; Yennamalli, Ragothaman; Campbell, Phillipa; Stoermer, Martin J; Fairlie, David P; Kobe, Bostjan; Young, Paul R

2009-12-01

The flaviviruses comprise a large group of related viruses, many of which pose a significant global human health threat, most notably the dengue viruses (DENV), West Nile virus (WNV) and yellow fever virus (YFV). Flaviviruses enter host cells via fusion of the viral and cellular membranes, a process mediated by the major viral envelope protein E as it undergoes a low pH induced conformational change in the endosomal compartment of the host cell. This essential entry stage in the flavivirus life cycle provides an attractive target for the development of antiviral agents. We performed an in silico docking screen of the Maybridge chemical database within a previously described ligand binding pocket in the dengue E protein structure that is thought to play a key role in the conformational transitions that lead to membrane fusion. The biological activity of selected compounds identified from this screen revealed low micromolar antiviral potency against dengue virus for two of the compounds. Our results also provide the first evidence that compounds selected to bind to this ligand binding site on the flavivirus E protein abrogate fusion activity. Interestingly, one of these compounds also has antiviral activity against both WNV (kunjin strain) and YFV.

Antiviral activities of Clinacanthus nutans (Burm.f.) Lindau extract against Cyprinid herpesvirus 3 in koi (Cyprinus carpio koi).

PubMed

Haetrakul, T; Dunbar, S G; Chansue, N

2018-04-01

Cyprinid herpesvirus 3 (CyHV-3) or koi herpesvirus (KHV) is a virulent viral infection in common carp and koi. The disease has caused global epizootic and economic loss in fish aquaculture and in the wild. Clinacanthus nutans (Burm. f.) Lindau is a well-known medicinal plant used in Thai traditional medicine. Virucidal effects of the plant extract against human herpes simplex virus have been reported. In this study, C. nutans crude extract was tested for antiviral activities against CyHV-3 in koi carp. Results showed effective antiviral activity against CyHV-3 pre- and post-infection. The 50% lethal concentration (LC 50 ) of extract was higher than 5 mg/ml. The 50% effective dose (ED 50 ) was 0.99 mg/ml, 0.78 mg/ml, 0.75 mg/ml and 0.71 mg/ml at 1, 2, 3 and 4 hr pre-infection, respectively. The ED 50 from post-infection tests was 2.05 mg/ml and 2.34 mg/ml at 0 and 24 hr, respectively. These results demonstrated that crude extract expressed antiviral activity against CyHV-3 and can be applied as a therapeutic agent in common carp and koi aquaculture. © 2018 John Wiley & Sons Ltd.

Hydroxychloroquine-inhibited dengue virus is associated with host defense machinery.

PubMed

Wang, Li-Fong; Lin, You-Sheng; Huang, Nan-Chieh; Yu, Chia-Yi; Tsai, Wei-Lun; Chen, Jih-Jung; Kubota, Toru; Matsuoka, Mayumi; Chen, Siang-Ru; Yang, Chih-Shiang; Lu, Ruo-Wei; Lin, Yi-Ling; Chang, Tsung-Hsien

2015-03-01

Hydroxychloroquine (HCQ) is an antimalarial drug also used in treating autoimmune diseases. Its antiviral activity was demonstrated in restricting HIV infection in vitro; however, the clinical implications remain controversial. Infection with dengue virus (DENV) is a global public health problem, and we lack an antiviral drug for DENV. Here, we evaluated the anti-DENV potential of treatment with HCQ. Immunofluorescence assays demonstrated that HCQ could inhibit DENV serotype 1-4 infection in vitro. RT-qPCR analysis of HCQ-treated cells showed induced expression of interferon (IFN)-related antiviral proteins and certain inflammatory cytokines. Mechanistic study suggested that HCQ activated the innate immune signaling pathways of IFN-β, AP-1, and NFκB. Knocking down mitochondrial antiviral signaling protein (MAVS), inhibiting TANK binding kinase 1 (TBK1)/inhibitor-κB kinase ɛ (IKKɛ), and blocking type I IFN receptor reduced the efficiency of HCQ against DENV-2 infection. Furthermore, HCQ significantly induced cellular production of reactive oxygen species (ROS), which was involved in the host defense system. Suppression of ROS production attenuated the innate immune activation and anti-DENV-2 effect of HCQ. In summary, HCQ triggers the host defense machinery by inducing ROS- and MAVS-mediated innate immune activation against DENV infection and may be a candidate drug for DENV infection.

Construction and characterization of a recombinant yellow fever virus stably expressing Gaussia luciferase.

PubMed

Kassar, Telissa C; Magalhães, Tereza; S, José V J; Carvalho, Amanda G O; Silva, Andréa N M R DA; Queiroz, Sabrina R A; Bertani, Giovani R; Gil, Laura H V G

2017-01-01

Yellow fever is an arthropod-borne viral disease that still poses high public health concerns, despite the availability of an effective vaccine. The development of recombinant viruses is of utmost importance for several types of studies, such as those aimed to dissect virus-host interactions and to search for novel antiviral strategies. Moreover, recombinant viruses expressing reporter genes may greatly facilitate these studies. Here, we report the construction of a recombinant yellow fever virus (YFV) expressing Gaussia luciferase (GLuc) (YFV-GLuc). We show, through RT-PCR, sequencing and measurement of GLuc activity, that stability of the heterologous gene was maintained after six passages. Furthermore, a direct association between GLuc expression and viral replication was observed (r2=0.9967), indicating that measurement of GLuc activity may be used to assess viral replication in different applications. In addition, we evaluated the use of the recombinant virus in an antiviral assay with recombinant human alfa-2b interferon. A 60% inhibition of GLuc expression was observed in cells infected with YFV-GLuc and incubated with IFN alfa-2b. Previously tested on YFV inhibition by plaque assays indicated a similar fold-decrease in viral replication. These results are valuable as they show the stability of YFV-GLuc and one of several possible applications of this construct.

Identification of Novel 5,6-Dimethoxyindan-1-one Derivatives as Antiviral Agents.

PubMed

Patil, Siddappa A; Patil, Vikrant; Patil, Renukadevi; Beaman, Kenneth; Patil, Shivaputra A

2017-01-01

Discovery of novel antiviral agents is essential because viral infection continues to threaten human life globally. Various heterocyclic small molecules have been developed as antiviral agents. The 5,6-dimethoxyindan-1-on nucleus is of considerable interest as this ring is the key constituent in a range of bioactive compounds, both naturally occurring and synthetic, and often of considerable complexity. The main purpose of this research was to discover and develop small molecule heterocycles as broad-spectrum of antiviral agents. A focused small set of 5,6-dimethoxyindan-1-one analogs (6-8) along with a thiopene derivative (9) was screened for selected viruses (Vaccinia virus - VACA, Human papillomavirus - HPV, Zika virus - ZIKV, Dengue virus - DENV, Measles virus - MV, Poliovirus 3 - PV, Rift Valley fever virus - RVFV, Tacaribe virus - TCRV, Venezuelan equine encephalitis virus - VEEV, Herpes simplex virus 1 -HSV-1 and Human cytomegalovirus - HCMV) using the National Institute of Allergy and Infectious Diseases (NIAID)'s Division of Microbiology and Infectious Diseases (DMID) antiviral screening program. These molecules demonstrated moderate to excellent antiviral activity towards variety of viruses. The 5,6-dimethoxyindan-1-one analog (7) demonstrated high efficacy towards vaccinia virus (EC50: <0.05 µM) and was nearly 232 times more potent than the standard drug Cidofovir (EC50: 11.59 µM) in primary assay whereas it demonstrated moderate activity (EC50: >30.00 µM) in secondary plaque reduction assay. The thiophene analog (9) has shown very good viral inhibition towards several viruses such as Human papillomavirus, Measles virus, Rift Valley fever virus, Tacaribe virus and Herpes simplex virus 1. Our research identified a novel 5,6-dimethoxyindan-1-one analog (compound 7), as a potent antiviral agent for vaccinia virus, and heterocyclic chalcone analog (compound 9) as a broad spectrum antiviral agent. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Development of a Scintillation Proximity Assay (SPA) Based, High Throughput Screening Feasible Method for the Identification of PDE12 Activity Modulators.

PubMed

Mang, Samuel; Bucher, Hannes; Nickolaus, Peter

2016-01-01

The scintillation proximity assay (SPA) technology has been widely used to establish high throughput screens (HTS) for a range of targets in the pharmaceutical industry. PDE12 (aka. 2'- phosphodiesterase) has been published to participate in the degradation of oligoadenylates that are involved in the establishment of an antiviral state via the activation of ribonuclease L (RNAse-L). Degradation of oligoadenylates by PDE12 terminates these antiviral activities, leading to decreased resistance of cells for a variety of viral pathogens. Therefore inhibitors of PDE12 are discussed as antiviral therapy. Here we describe the use of the yttrium silicate SPA bead technology to assess inhibitory activity of compounds against PDE12 in a homogeneous, robust HTS feasible assay using tritiated adenosine-P-adenylate ([3H]ApA) as substrate. We found that the used [3H]ApA educt, was not able to bind to SPA beads, whereas the product [3H]AMP, as known before, was able to bind to SPA beads. This enables the measurement of PDE12 activity on [3H]ApA as a substrate using a wallac microbeta counter. This method describes a robust and high throughput capable format in terms of specificity, commonly used compound solvents, ease of detection and assay matrices. The method could facilitate the search for PDE12 inhibitors as antiviral compounds.

In vitro antiviral activities of Caesalpinia pulcherrima and its related flavonoids.

PubMed

Chiang, L C; Chiang, W; Liu, M C; Lin, C C

2003-08-01

The aim of this study was to search for new antiviral agents from Chinese herbal medicine. Pure flavonoids and aqueous extracts of Caesalpinia pulcherrima Swartz were used in experiments to test their influence on a series of viruses, namely herpesviruses (HSV-1, HSV-2) and adenoviruses (ADV-3, ADV-8, ADV-11). The EC50 was defined as the concentration required to achieve 50% protection against virus-induced cytopathic effects, and the selectivity index (SI) was determined as the ratio of CC50 (concentration of 50% cellular cytotoxicity) to EC50. Results showed that aqueous extracts of C. pulcherrima and its related quercetin possessed a broad-spectrum antiviral activity. Among them, the strongest activities against ADV-8 were fruit and seed (EC50 = 41.2 mg/l, SI = 83.2), stem and leaf (EC50 = 61.8 mg/l, SI = 52.1) and flower (EC50 = 177.9 mg/l, SI = 15.5), whereas quercetin possessed the strongest anti-ADV-3 activity (EC50 = 24.3 mg/l, SI = 20.4). In conclusion, some compounds of C. pulcherrima which possess antiviral activities may be derived from the flavonoid of quercetin. The mode of action of quercetin against HSV-1 and ADV-3 was found to be at the early stage of multiplication and with SI values greater than 20, suggesting the potential use of this compound for treatment of the infection caused by these two viruses.

The anti-papillomavirus activity of human and bovine lactoferricin.

PubMed

Mistry, Nitesh; Drobni, Peter; Näslund, Jonas; Sunkari, Vivekananda Gupta; Jenssen, Håvard; Evander, Magnus

2007-09-01

Human papillomavirus (HPV) cause common warts, laryngeal papilloma and genital condylomata and is necessary for the development of cervical cancer. We have previously found that lactoferrin has antiviral activity against HPV-16 and others have demonstrated that lactoferricin, an N-terminal fragment of lactoferrin, has inhibitory activities against several viruses. Two cell lines and two virus types, HPV-5 and HPV-16, were used to study if lactoferrin and lactoferricin could inhibit HPV pseudovirus (PsV) infection. We demonstrated that bovine lactoferrin (bLf) and human lactoferrin (hLf) were both potent inhibitors of HPV-5 and -16 PsV infections. Among the four lactoferricin derivatives we analyzed, a 15 amino acid peptide from bovine lactoferricin (bLfcin) 17-31 was the most potent inhibitor of both HPV-5 and HPV-16 PsV infection. Among the other derivatives, the human lactoferricin (hLfcin) 1-49 showed some antiviral activity against HPV PsV infection while bLfcin 17-42 inhibited only HPV-5 PsV infection in one of the cell lines. When we studied initial attachment of HPV-16, only bLfcin 17-42 and hLfcin 1-49 had an antiviral effect. This is the first time that lactoferricin was demonstrated to have an inhibitory effect on HPV infection and the antiviral activity differed depending on size, charge and structures of the lactoferricin.

[Studies on evaluation of natural products for antiviral effects and their applications].

PubMed

Hayashi, Toshimitsu

2008-01-01

In the search for novel antiviral molecules from natural products, we have discovered various antiviral molecules with characteristic mechanisms of action. Scopadulciol (SDC), isolated from the tropical medicinal plant Scoparia dulcis L., showed stimulatory effects on the antiviral potency of acyclovir (ACV) or ganciclovir (GCV). This effect of SDC was exerted via the activation of viral thymidine kinase (HSV-1 TK) and, as a result, an increase in the cellular concentration of the active form of ACV/GCV, i.e., the triphosphate of ACV or GCV. On the basis of these experimental results, cancer gene therapy using the HSV-1 tk gene and ACV/GCV together with SDC was found to be effective in suppressing the growth of cancer cells in animals. Acidic polysaccharides such as calcium spirulan (Ca-SP) from Spirulina platensis, nostoflan from Nostoc flagelliforme, and a fucoidan from the sporophyll of Undaria pinnatifida (mekabu fucoidan) were also found to be potent inhibitors against several enveloped viruses. Their antiviral potency was dependent on molecular weight and content of the sulfate or carboxyl group as well as counterion species chelating with sulfate groups, indicating the importance of the three-dimensional structure of the molecules. In addition, unlike dextran sulfate, Ca-SP was shown to target not only viral absorption/penetration stages but also some replication stages of progeny viruses after penetration into cells. When mekabu fucoidan or nostoflan was administered with oseltamivir phosphate, their synergistic antiviral effects on influenza A virus were confirmed in vitro as well as in vivo.

RO 90-7501 Enhances TLR3 and RLR Agonist Induced Antiviral Response

PubMed Central

Guo, Fang; Mead, Jennifer; Aliya, Nishat; Wang, Lijuan; Cuconati, Andrea; Wei, Lai; Li, Kui; Block, Timothy M.; Guo, Ju-Tao; Chang, Jinhong

2012-01-01

Recognition of virus infection by innate pattern recognition receptors (PRRs), including membrane-associated toll-like receptors (TLR) and cytoplasmic RIG-I-like receptors (RLR), activates cascades of signal transduction pathways leading to production of type I interferons (IFN) and proinflammatory cytokines that orchestrate the elimination of the viruses. Although it has been demonstrated that PRR-mediated innate immunity plays an essential role in defending virus from infection, it also occasionally results in overwhelming production of proinflammatory cytokines that cause severe inflammation, blood vessel leakage and tissue damage. In our efforts to identify small molecules that selectively enhance PRR-mediated antiviral, but not the detrimental inflammatory response, we discovered a compound, RO 90–7501 (‘2’-(4-Aminophenyl)-[2,5′-bi-1H-benzimidazol]-5-amine), that significantly promoted both TLR3 and RLR ligand-induced IFN-β gene expression and antiviral response, most likely via selective activation of p38 mitogen-activated protein kinase (MAPK) pathway. Our results thus imply that pharmacological modulation of PRR signal transduction pathways in favor of the induction of a beneficial antiviral response can be a novel therapeutic strategy. PMID:23056170

HIV enhancing activity of semen impairs the antiviral efficacy of microbicides

PubMed Central

Zirafi, Onofrio; Kim, Kyeong-Ae; Roan, Nadia R.; Kluge, Silvia F.; Müller, Janis A.; Jiang, Shibo; Mayer, Benjamin; Greene, Warner C.; Kirchhoff, Frank; Münch, Jan

2015-01-01

Topically applied microbicides potently inhibit HIV in vitro but have largely failed to exert protective effects in clinical trials. One possible reason for this discrepancy is that the preclinical testing of microbicides does not faithfully reflect the conditions of HIV sexual transmission. Here, we report that candidate microbicides that target HIV components show greatly reduced antiviral efficacy in the presence of semen, the main vector for HIV transmission. This diminished antiviral activity was dependent on the ability of amyloid fibrils in semen to enhance the infectivity of HIV. Thus, the anti-HIV efficacy of microbicides determined in the absence of semen greatly underestimated the drug concentrations needed to block semen-exposed virus. One notable exception was Maraviroc. This HIV entry inhibitor targets the host cell CCR5 coreceptor and was highly active against both untreated and semen-exposed HIV. These data help explain why microbicides have failed to protect against HIV in clinical trials and suggest that antiviral compounds targeting host factors hold promise for further development. These findings also suggest that the in vitro efficacy of candidate microbicides should be determined in the presence of semen to identify the best candidates for the prevention of HIV sexual transmission. PMID:25391483

Cross Talk between PML and p53 during Poliovirus Infection: Implications for Antiviral Defense

PubMed Central

Pampin, Mathieu; Simonin, Yannick; Blondel, Bruno; Percherancier, Yann; Chelbi-Alix, Mounira K.

2006-01-01

PML nuclear bodies (NBs) are dynamic intranuclear structures harboring numerous transiently or permanently localized proteins. PML, the NBs' organizer, is directly induced by interferon, and its expression is critical for antiviral host defense. We describe herein the molecular events following poliovirus infection that lead to PML-dependent p53 activation and protection against virus infection. Poliovirus infection induces PML phosphorylation through the extracellular signal-regulated kinase pathway, increases PML SUMOylation, and induces its transfer from the nucleoplasm to the nuclear matrix. These events result in the recruitment of p53 to PML NBs, p53 phosphorylation on Ser15, and activation of p53 target genes leading to the induction of apoptosis. Moreover, the knock-down of p53 by small interfering RNA results in higher poliovirus replication, suggesting that p53 participates in antiviral defense. This effect, which requires the presence of PML, is transient since poliovirus targets p53 by inducing its degradation in a proteasome- and MDM2-dependent manner. Our results provide evidence of how poliovirus counteracts p53 antiviral activity by regulating PML and NBs, thus leading to p53 degradation. PMID:16912307

Cross talk between PML and p53 during poliovirus infection: implications for antiviral defense.

PubMed

Pampin, Mathieu; Simonin, Yannick; Blondel, Bruno; Percherancier, Yann; Chelbi-Alix, Mounira K

2006-09-01

PML nuclear bodies (NBs) are dynamic intranuclear structures harboring numerous transiently or permanently localized proteins. PML, the NBs' organizer, is directly induced by interferon, and its expression is critical for antiviral host defense. We describe herein the molecular events following poliovirus infection that lead to PML-dependent p53 activation and protection against virus infection. Poliovirus infection induces PML phosphorylation through the extracellular signal-regulated kinase pathway, increases PML SUMOylation, and induces its transfer from the nucleoplasm to the nuclear matrix. These events result in the recruitment of p53 to PML NBs, p53 phosphorylation on Ser15, and activation of p53 target genes leading to the induction of apoptosis. Moreover, the knock-down of p53 by small interfering RNA results in higher poliovirus replication, suggesting that p53 participates in antiviral defense. This effect, which requires the presence of PML, is transient since poliovirus targets p53 by inducing its degradation in a proteasome- and MDM2-dependent manner. Our results provide evidence of how poliovirus counteracts p53 antiviral activity by regulating PML and NBs, thus leading to p53 degradation.

Inhibition of HSV cell-to-cell spread by lactoferrin and lactoferricin.

PubMed

Jenssen, Håvard; Sandvik, Kjersti; Andersen, Jeanette H; Hancock, Robert E W; Gutteberg, Tore J

2008-09-01

The milk protein lactoferrin (Lf) has multiple functions, including immune stimulation and antiviral activity towards herpes simplex virus 1 and 2 (HSV-1 and HSV-2); antiviral activity has also been reported for the N-terminal pepsin-derived fragment lactoferricin (Lfcin). The anti-HSV mode of action of Lf and Lfcin is assumed to involve, in part, their interaction with the cell surface glycosaminoglycan heparan sulfate, thereby blocking of viral entry. In this study we investigated the ability of human and bovine Lf and Lfcin to inhibit viral cell-to-cell spread as well as the involvement of cell surface glycosaminoglycans during viral cell-to-cell spread. Lf and Lfcin from both human and bovine origin, inhibited cell-to-cell spread of both HSV-1 and HSV-2. Inhibition of cell-to-cell spread by bovine Lfcin involved cell surface chondroitin sulfate. Based on transmission electron microscopy studies, human Lfcin, like bovine Lfcin, was randomly distributed intracellularly, thus differences in their antiviral activity could not be explained by differences in their distribution. In contrast, the cellular localization of iron-saturated (holo)-Lf appeared to differ from that of apo-Lf, indicating that holo- and apo-Lf may exhibit different antiviral mechanisms.

Inhibitory effects of lupene-derived pentacyclic triterpenoids from Bursera simaruba on HSV-1 and HSV-2 in vitro replication.

PubMed

Álvarez, Ángel L; Habtemariam, Solomon; Parra, Francisco

2015-01-01

The cytotoxicity and antiviral properties of Bursera simaruba against herpes simplex viruses (HSV-1 and HSV-2) were investigated through a bioactivity-guided isolation protocol. The plant material was fractionated using solvent-solvent partitioning, size-exclusion and thin-layer chromatography. The antiviral compounds present in the most active fractions were identified by means of LC-MS and NMR. Three different methods were compared during the evaluation of antiviral activity of samples. Four lupene-related pentacyclic triterpenes were found to be responsible for the anti-herpesvirus effects of B. simaruba and were isolated from this species for the first time. The selective indexes (SI) of B. simaruba-derived samples ranged from 7.7 to 201.9.

High content image-based screening of a protease inhibitor library reveals compounds broadly active against Rift Valley fever virus and other highly pathogenic RNA viruses.

PubMed

Mudhasani, Rajini; Kota, Krishna P; Retterer, Cary; Tran, Julie P; Whitehouse, Chris A; Bavari, Sina

2014-08-01

High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV) and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥ 50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362), which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their mechanism of action and any possible deleterious effects on host cellular biology.

High Content Image-Based Screening of a Protease Inhibitor Library Reveals Compounds Broadly Active against Rift Valley Fever Virus and Other Highly Pathogenic RNA Viruses

PubMed Central

Mudhasani, Rajini; Kota, Krishna P.; Retterer, Cary; Tran, Julie P.; Whitehouse, Chris A.; Bavari, Sina

2014-01-01

High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV) and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362), which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their mechanism of action and any possible deleterious effects on host cellular biology. PMID:25144302

Paramyxovirus V Proteins Interact with the RIG-I/TRIM25 Regulatory Complex and Inhibit RIG-I Signaling.

PubMed

Sánchez-Aparicio, Maria T; Feinman, Leighland J; García-Sastre, Adolfo; Shaw, Megan L

2018-03-15

Paramyxovirus V proteins are known antagonists of the RIG-I-like receptor (RLR)-mediated interferon induction pathway, interacting with and inhibiting the RLR MDA5. We report interactions between the Nipah virus V protein and both RIG-I regulatory protein TRIM25 and RIG-I. We also observed interactions between these host proteins and the V proteins of measles virus, Sendai virus, and parainfluenza virus. These interactions are mediated by the conserved C-terminal domain of the V protein, which binds to the tandem caspase activation and recruitment domains (CARDs) of RIG-I (the region of TRIM25 ubiquitination) and to the SPRY domain of TRIM25, which mediates TRIM25 interaction with the RIG-I CARDs. Furthermore, we show that V interaction with TRIM25 and RIG-I prevents TRIM25-mediated ubiquitination of RIG-I and disrupts downstream RIG-I signaling to the mitochondrial antiviral signaling protein. This is a novel mechanism for innate immune inhibition by paramyxovirus V proteins, distinct from other known V protein functions such as MDA5 and STAT1 antagonism. IMPORTANCE The host RIG-I signaling pathway is a key early obstacle to paramyxovirus infection, as it results in rapid induction of an antiviral response. This study shows that paramyxovirus V proteins interact with and inhibit the activation of RIG-I, thereby interrupting the antiviral signaling pathway and facilitating virus replication. Copyright © 2018 American Society for Microbiology.

Anticancer and antiviral effects and inactivation of S-adenosyl-L-homocysteine hydrolase with 5'-carboxaldehydes and oximes synthesized from adenosine and sugar-modified analogues.

PubMed

Wnuk, S F; Yuan, C S; Borchardt, R T; Balzarini, J; De Clercq, E; Robins, M J

1997-05-23

Selectively protected adenine nucleosides were converted into 5'-carboxaldehyde analogues by Moffatt oxidation (dimethyl sulfoxide/dicyclohexylcarbodiimide/dichloroacetic acid) or with the Dess-Martin periodinane reagent. Hydrolysis of a 5'-fluoro-5'-S-methyl-5'-thio (alpha-fluoro thioether) arabinosyl derivative also gave the 5'-carboxaldehyde. Treatment of 5'-carboxaldehydes with hydroxylamine [or O-(methyl, ethyl, and benzyl)hydroxylamine] hydrochloride gave E/Z oximes. Treatment of purified oximes with aqueous trifluoroacetic acid and acetone effected trans-oximation to provide clean samples of 5'-carboxaldehydes. Adenosine (Ado)-5'-carboxaldehyde and its 4'-epimer are potent inhibitors of S-adenosyl-L-homocysteine (AdoHcy) hydrolase. They bind efficiently to the enzyme and undergo oxidation at C3' to give 3'-keto analogues with concomitant reduction of the NAD+ cofactor to give an inactive, tightly bound NADH-enzyme complex (type I cofactor-depletion inhibition). Potent type I inhibition was observed with 5'-carboxaldehydes that contain a ribo cis-2',3'-glycol. Their oxime derivatives are "proinhibitors" that undergo enzyme-catalyzed hydrolysis to release the inhibitors at the active site. The 2'-deoxy and 2'-epimeric (arabinosyl) analogues were much weaker inhibitors, and the 3'-deoxy compounds bind very weakly. Ado-5'-carboxaldehyde oxime had potent cytotoxicity in tumor cell lines and was toxic to normal human cells. Analogues had weaker cytotoxic and antiviral potencies, and the 3'-deoxy compounds were essentially devoid of cytotoxic and antiviral activity.

Anti-dengue virus serotype 2 activity and mode of action of a novel peptide.

PubMed

Chew, M-F; Tham, H-W; Rajik, M; Sharifah, S H

2015-10-01

To identify a novel antiviral peptide against dengue virus serotype 2 (DENV-2) by screening a phage display peptide library and to evaluate its in vitro antiviral activity and mode of action. A phage display peptide library was biopanned against purified DENV-2 and resulted in the identification and selection of a peptide (peptide gg-ww) for further investigation. ELISA was performed, and peptide gg-ww was shown to possess the highest binding affinity against DENV-2. Thus, peptide gg-ww was synthesized for cytotoxicity and antiviral assays. Virus plaque reduction assay, real-time PCR and immunofluorescence assay were used to investigate the inhibitory effect of peptide gg-ww on DENV-2 infection in Vero cells. Three different assays (pre-, simultaneous and post-treatments assays) were performed to investigate the peptide's mode of action. Results indicated that peptide gg-ww possessed strong antiviral activity with a ~96% inhibition rate, which was achieved at 250 μmol l(-1) . Viral replication was inhibited during a simultaneous treatment assay, indicating that the entry of the virus was impeded by this peptide. Peptide gg-ww displayed antiviral action against DENV-2 by targeting an early stage of viral replication (i.e. during viral entry). Peptide gg-ww may represent a new therapeutic candidate for the treatment of DENV infections and is a potential candidate to be developed as a peptide drug. © 2015 The Society for Applied Microbiology.

Structural insights into the anti-HIV activity of the Oscillatoria agardhii agglutinin homolog lectin family.

PubMed

Koharudin, Leonardus M I; Kollipara, Sireesha; Aiken, Christopher; Gronenborn, Angela M

2012-09-28

Oscillatoria agardhii agglutinin homolog (OAAH) proteins belong to a recently discovered lectin family. All members contain a sequence repeat of ~66 amino acids, with the number of repeats varying among different family members. Apart from data for the founding member OAA, neither three-dimensional structures, information about carbohydrate binding specificities, nor antiviral activity data have been available up to now for any other members of the OAAH family. To elucidate the structural basis for the antiviral mechanism of OAAHs, we determined the crystal structures of Pseudomonas fluorescens and Myxococcus xanthus lectins. Both proteins exhibit the same fold, resembling the founding family member, OAA, with minor differences in loop conformations. Carbohydrate binding studies by NMR and x-ray structures of glycan-lectin complexes reveal that the number of sugar binding sites corresponds to the number of sequence repeats in each protein. As for OAA, tight and specific binding to α3,α6-mannopentaose was observed. All the OAAH proteins described here exhibit potent anti-HIV activity at comparable levels. Altogether, our results provide structural details of the protein-carbohydrate interaction for this novel lectin family and insights into the molecular basis of their HIV inactivation properties.

The agmatine-containing poly(amidoamine) polymer AGMA1 binds cell surface heparan sulfates and prevents attachment of mucosal human papillomaviruses.

PubMed

Cagno, Valeria; Donalisio, Manuela; Bugatti, Antonella; Civra, Andrea; Cavalli, Roberta; Ranucci, Elisabetta; Ferruti, Paolo; Rusnati, Marco; Lembo, David

2015-09-01

The agmatine-containing poly(amidoamine) polymer AGMA1 was recently shown to inhibit the infectivity of several viruses, including human papillomavirus 16 (HPV-16), that exploit cell surface heparan sulfate proteoglycans (HSPGs) as attachment receptors. The aim of this work was to assess the antiviral activity of AGMA1 and its spectrum of activity against a panel of low-risk and high-risk HPVs and to elucidate its mechanism of action. AGMA1 was found to be a potent inhibitor of mucosal HPV types (i.e., types 16, 31, 45, and 6) in pseudovirus-based neutralization assays. The 50% inhibitory concentration was between 0.34 μg/ml and 0.73 μg/ml, and no evidence of cytotoxicity was observed. AGMA1 interacted with immobilized heparin and with cellular heparan sulfates, exerting its antiviral action by preventing virus attachment to the cell surface. The findings from this study indicate that AGMA1 is a leading candidate compound for further development as an active ingredient of a topical microbicide against HPV and other sexually transmitted viral infections. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Imiquimod and resiquimod as novel immunomodulators.

PubMed

Dockrell, D H; Kinghorn, G R

2001-12-01

Augmenting the host's natural immune response to viruses by the administration of exogenous cytokines such as interferon-alpha (IFN-alpha) is a strategy increasingly employed in antiviral therapeutics. Enhancing the release of endogenous cytokines is, however, an alternative approach. The imidazoquinolinamines imiquimod and resiquimod have demonstrated potency as inducers of IFN-alpha and other cytokines both in vitro and in vivo. Cytokine gene activation is mediated via the signal transducer and activator of transcription 1 (STAT-1) and involves the transcription factors NFkappaB and alpha4F1. Antiviral activity has been demonstrated against a variety of viruses, and clinical efficacy has been demonstrated against genital warts, herpes genitalis and molluscum contagiosum. Imiquimod is administered as a 5% cream (Aldara) and has been licensed for the treatment of anogenital warts in immunocompetent patients. Complete clearance of warts has been observed in up to half of treated patients with only local side effects reported. Resiquimod can be administered topically but also exists as an oral formulation. The range of potential infections for which these agents may have clinical utility includes chronic hepatitis C virus infection and Kaposi's sarcoma. In addition, the imidazoquinolinamines may find roles in the therapy of cancers and as vaccine adjuvants.

Effects of Smoking on Pegylated Interferon alpha 2a and First Generation Protease Inhibitor-based Antiviral Therapy in Naïve Patients Infected with Hepatitis C Virus Genotype 1.

PubMed

Zimmermann, Tim; Hueppe, Dietrich; Mauss, Stefan; Buggisch, Peter; Pfeiffer-Vornkahl, Heike; Grimm, Daniel; Galle, Peter R; Alshuth, Ulrich

2016-03-01

Smoking has multiple effects on factors influencing hepatitis C and antiviral therapy, including lipid metabolism, fibrosis, platelet count and adherence aspects. The aim of this analysis was to determine the impact of smoking on hepatitis C virus antiviral therapy. Data of two cohorts of an observational multicenter study including therapy-naïve patients infected with genotype 1 hepatitis C virus (HCV) treated with dual antiviral therapy (n=7,796) with pegylated interferon alpha 2a in combination with ribavirin, or triple antiviral therapy (n=1,122) containing telaprevir or boceprevir, were analysed. In the univariate matched pair analysis of dual antiviral therapy patients (n=584), smoking was significantly associated with lower sustained viral response rates (p=0.026, OR 0.69 CI: 0.50 - 0.96). The effect of smoking on sustained viral response remained significant (p=0.028, OR 0.67 CI: 0.47 - 0.96) in the multivariate analysis when adjusting for all other baseline parameters with a significant association in the univariate analysis, i.e. diabetes, fibrosis, body mass index, transaminases and baseline viral load. Under protease inhibitors the influence of smoking on virological response did not arise. Smoking has a negative impact on antiviral therapy in naïve patients infected with HCV genotype 1 independently of age, gender, history of drug use or alcoholic liver disease. The effects of smoking might be overcome by the new antiviral agents.

Combinations of Adefovir with Nucleoside Analogs Produce Additive Antiviral Effects against Hepatitis B Virus In Vitro

PubMed Central

Delaney, William E.; Yang, Huiling; Miller, Michael D.; Gibbs, Craig S.; Xiong, Shelly

2004-01-01

Combination therapies may be required for long-term management of some patients chronically infected with hepatitis B virus (HBV). Adefovir is a nucleotide analog that has similar activity against wild-type and lamivudine-resistant HBV. In contrast to lamivudine, clinical resistance to the prodrug adefovir dipivoxil emerges infrequently. Based on its clinical efficacy and low frequency of resistance, adefovir dipivoxil may form an important component of combination regimens. We therefore investigated the in vitro antiviral efficacy of combinations of adefovir with other nucleoside analogs (lamivudine, entecavir, emtricitabine [FTC],and telbivudine [L-dT]) and the nucleotide analog tenofovir. Using a novel stable cell line that expresses high levels of wild-type HBV, we assayed the antiviral activity of each drug alone and in combination with adefovir. All two-drug combinations resulted in greater antiviral effects than treatments with single agents and could be characterized as additive by the Bliss independence model. Analysis using the Loewe additivity model indicated that adefovir exerted additive antiviral effects when combined with lamivudine, FTC, or L-dT and moderately synergistic effects when combined with entecavir or tenofovir. There was no evidence of cytotoxicity with any of the drugs when used alone or in combination at the tested doses. PMID:15388423

[Antiviral activity of IgG subclasses of immunoglobulin preparations for intravenous use].

PubMed

Litwińska, B; Bucholc, B; Biesiadecka, A; Kańtoch, M

1993-01-01

Preparations of human immunoglobulins for intravenous use (IVIG) should contain proper percentage of IgG subclasses, responding to physiological preparations with preserved activity of antibodies. The study was aimed at establishment of activity against measles, CMV and HSV viruses in individual subclasses of Bioglobulin (Biomed, Warszawa) and a comparison with preparation Polygam (Baxter, USA). Indirect immunofluorescence test was used. The results revealed presence of antiviral activity mostly in subclass IgG1 and also in IgG3, which is in keeping with results obtained by other authors. We have found an anti-HSV activity in a subclass IgG2 and IgG4 in IVIG preparations which was not yet described in the literature; it is confirmed, however, in investigations with application of sera of HSV-positive persons. These discrepancies may be caused by different methods of detection. Viral antigens in ELISA and IF tests may differ among themselves by content of individual epitopes. Basing on obtained results it can be stated that Polish preparation Bioglobulin (in which for the first time antiviral activity was determined in subclasses) is comparable with Polygam.

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

Understanding the Mechanism of the Broad-Spectrum Antiviral Activity of Favipiravir (T-705): Key Role of the F1 Motif of the Viral Polymerase.

PubMed

Abdelnabi, Rana; Morais, Ana Theresa Silveira de; Leyssen, Pieter; Imbert, Isabelle; Beaucourt, Stéphanie; Blanc, Hervé; Froeyen, Mathy; Vignuzzi, Marco; Canard, Bruno; Neyts, Johan; Delang, Leen

2017-06-15

Favipiravir (T-705) is a broad-spectrum antiviral agent that has been approved in Japan for the treatment of influenza virus infections. T-705 also inhibits the replication of various RNA viruses, including chikungunya virus (CHIKV). We demonstrated earlier that the K291R mutation in the F1 motif of the RNA-dependent RNA polymerase (RdRp) of CHIKV is responsible for low-level resistance to T-705. Interestingly, this lysine is highly conserved in the RdRp of positive-sense single-stranded RNA (+ssRNA) viruses. To obtain insights into the unique broad-spectrum antiviral activity of T-705, we explored the role of this lysine using another +ssRNA virus, namely, coxsackievirus B3 (CVB3). Introduction of the corresponding K-to-R substitution in the CVB3 RdRp (K159R) resulted in a nonviable virus. Replication competence of the K159R variant was restored by spontaneous acquisition of an A239G substitution in the RdRp. A mutagenesis analysis at position K159 identified the K159M variant as the only other viable variant which had also acquired the A239G substitution. The K159 substitutions markedly decreased the processivity of the purified viral RdRp, which was restored by the introduction of the A239G mutation. The K159R A239G and K159M A239G variants proved, surprisingly, more susceptible than the wild-type virus to T-705 and exhibited lower fidelity in polymerase assays. Furthermore, the K159R A239G variant was found to be highly attenuated in mice. We thus demonstrate that the conserved lysine in the F1 motif of the RdRp of +ssRNA viruses is involved in the broad-spectrum antiviral activity of T-705 and that it is a key amino acid for the proper functioning of the enzyme. IMPORTANCE In this study, we report the key role of a highly conserved lysine residue of the viral polymerase in the broad-spectrum antiviral activity of favipiravir (T-705) against positive-sense single-stranded RNA viruses. Substitutions of this conserved lysine have a major negative impact on the functionality of the RdRp. Furthermore, we show that this lysine is involved in the fidelity of the RdRp and that the RdRp fidelity influences the sensitivity of the virus for the antiviral efficacy of T-705. Consequently, these results provide insights into the mechanism of the antiviral activity of T-705 and may lay the basis for the design of novel chemical scaffolds that may be endowed with a more potent broad-spectrum antiviral activity than that of T-705. Copyright © 2017 American Society for Microbiology.

Quantitative autoradiographic mapping of focal herpes simplex virus encephalitis using a radiolabeled antiviral drug

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

Price, R.

1984-12-18

A method of mapping herpes simplex viral infection comprising administering a radiolabeled antiviral active 5-substituted 1-(2'-deoxy-2'-substituted-D-arabinofuranosyl) pyrimidine nucleoside to the infected subject, and scanning the area in which the infection is to be mapped for the radiolabel.

Fragment-based discovery of a new family of non-peptidic small-molecule cyclophilin inhibitors with potent antiviral activities

PubMed Central

Ahmed-Belkacem, Abdelhakim; Colliandre, Lionel; Ahnou, Nazim; Nevers, Quentin; Gelin, Muriel; Bessin, Yannick; Brillet, Rozenn; Cala, Olivier; Douguet, Dominique; Bourguet, William; Krimm, Isabelle; Pawlotsky, Jean-Michel; Guichou, Jean- François

2016-01-01

Cyclophilins are peptidyl-prolyl cis/trans isomerases (PPIase) that catalyse the interconversion of the peptide bond at proline residues. Several cyclophilins play a pivotal role in the life cycle of a number of viruses. The existing cyclophilin inhibitors, all derived from cyclosporine A or sanglifehrin A, have disadvantages, including their size, potential for side effects unrelated to cyclophilin inhibition and drug–drug interactions, unclear antiviral spectrum and manufacturing issues. Here we use a fragment-based drug discovery approach using nucleic magnetic resonance, X-ray crystallography and structure-based compound optimization to generate a new family of non-peptidic, small-molecule cyclophilin inhibitors with potent in vitro PPIase inhibitory activity and antiviral activity against hepatitis C virus, human immunodeficiency virus and coronaviruses. This family of compounds has the potential for broad-spectrum, high-barrier-to-resistance treatment of viral infections. PMID:27652979

Synthesis and antiviral bioactivities of 2-aryl- or 2-methyl-3-(substituted- benzalamino)-4(3H)-quinazolinone derivatives.

PubMed

Gao, Xingwen; Cai, Xuejian; Yan, Kai; Song, Baoan; Gao, Lili; Chen, Zhuo

2007-12-27

A simple and general method has been developed for the synthesis of various4(3H)-quinazolinone derivatives by the treatment of the appropriate 3-amino-2-aryl-4(3H)-quinazolinone with a substituted benzaldehyde in ethanol. The structures of the compoundswere characterized by elemental analysis, IR, (1)H-NMR and (13)C-NMR spectra. The title 2-aryl- or 2-methyl-3-(substituted-benzalamino)-4(3H)-quinazolinone compounds III-1~III-31 were found to possess moderate to good antiviral activity. Semi-quantitative PCR andReal Time PCR assays were used to ascertain the target of action of compound III-31against TMV. The studies suggest that III-31 possesses antiviral activity due to inductionof up-regulation of PR-1a and PR-5, thereby inhibiting virus proliferation and movementby enhancement of the activity of some defensive enzyme.

Anti-viral activity of galectin-1 from flounder Paralichthys olivaceus.

PubMed

Liu, Shousheng; Hu, Guobin; Sun, Chen; Zhang, Shicui

2013-06-01

Galectins are a family of Ca(2+)-independent soluble lectins characterized by their affinity to β-galactosides. Mammalian galectins have been shown to play a defense role against certain bacteria, fungi and viruses. However, the immunological functions of galectins in fish is poorly characterized. Here we demonstrated that the expression of galectin-1 gene from the flounder Paralichthys olivaceus was decreased in the initial 8 h after challenge with poly I:C, then increased markedly from 24 h onwards, and the recombinant galectin-1 was able to neutralize the lymphocystis disease virus (LCDV), inhibiting the formation of cytopathic effects. In addition, the recombinant galectin had a potential anti-inflammatory activity against infection by LCDV, and was able to restrain the overexpression of the anti-viral protein gene mx against virus infection. These results indicate that flounder galectin-1 has an anti-viral activity, capable of reducing LCDV pathogenicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Docking of anti-HIV-1 oxoquinoline-acylhydrazone derivatives as potential HSV-1 DNA polymerase inhibitors

NASA Astrophysics Data System (ADS)

Yoneda, Julliane Diniz; Albuquerque, Magaly Girão; Leal, Kátia Zaccur; Santos, Fernanda da Costa; Batalha, Pedro Netto; Brozeguini, Leonardo; Seidl, Peter R.; de Alencastro, Ricardo Bicca; Cunha, Anna Cláudia; de Souza, Maria Cecília B. V.; Ferreira, Vitor F.; Giongo, Viveca A.; Cirne-Santos, Cláudio; Paixão, Izabel C. P.

2014-09-01

Although there are many antiviral drugs available for the treatment of herpes simplex virus (HSV) infections, still the synthesis of new anti-HSV candidates is an important strategy to be pursued, due to the emergency of resistant HSV strains mainly in human immunodeficiency virus (HIV) co-infected patients. Some 1,4-dihydro-4-oxoquinolines, such as PNU-183792 (1), show a broad spectrum antiviral activity against human herpes viruses, inhibiting the viral DNA polymerase (POL) without affecting the human POLs. Thus, on an ongoing antiviral research project, our group has synthesized ribonucleosides containing the 1,4-dihydro-4-oxoquinoline (quinolone) heterocyclic moiety, such as the 6-Cl derivative (2), which is a dual antiviral agent (HSV-1 and HIV-1). Molecular dynamics simulations of the complexes of 1 and 2 with the HSV-1 POL suggest that structural modifications of 2 should increase its experimental anti-HSV-1 activity, since its ribosyl and carboxyl groups are highly hydrophilic to interact with a hydrophobic pocket of this enzyme. Therefore, in this work, comparative molecular docking simulations of 1 and three new synthesized oxoquinoline-acylhydrazone HIV-1 inhibitors (3-5), which do not contain those hydrophilic groups, were carried out, in order to access these modifications in the proposition of new potential anti-HSV-1 agents, but maintaining the anti-HIV-1 activity. Among the docked compounds, the oxoquinoline-acylhydrazone 3 is the best candidate for an anti-HSV-1 agent, and, in addition, it showed anti-HIV-1 activity (EC50 = 3.4 ± 0.3 μM). Compounds 2 and 3 were used as templates in the design of four new oxoquinoline-acylhydrazones (6-9) as potential anti-HSV-1 agents to increase the antiviral activity of 2. Among the docked compounds, oxoquinoline-acylhydrazone 7 was selected as the best candidate for further development of dual anti-HIV/HSV activity.

Antiviral Activity of Hatay Propolis Against Replication of Herpes Simplex Virus Type 1 and Type 2

PubMed Central

Yildirim, Ayse; Duran, Gulay Gulbol; Duran, Nizami; Jenedi, Kemal; Bolgul, Behiye Sezgin; Miraloglu, Meral; Muz, Mustafa

2016-01-01

Background Propolis is a bee product widely used in folk medicine and possessing many pharmacological properties. In this study we aimed to investigate: i) the antiviral activities of Hatay propolis samples against HSV-1 and HSV-2 in HEp-2 cell line, and ii) the presence of the synergistic effects of propolis with acyclovir against these viruses. Material/Methods All experiments were carried out in HEp-2 cell cultures. Proliferation assays were performed in 24-well flat bottom microplates. We inoculated 1×105 cells per ml and RPMI 1640 medium with 10% fetal calf serum into each well. Studies to determine cytotoxic effect were performed. To investigate the presence of antiviral activity of propolis samples, different concentrations of propolis (3200, 1600, 800, 400, 200, 100, 75, 50, and 25 μg/mL) were added into the culture medium. The amplifications of HSV-1 and HSV-2 DNA were performed by real-time PCR method. Acyclovir (Sigma, USA) was chosen as a positive control. Cell morphology was evaluated by scanning electron microscopy (SEM). Results The replication of HSV-1 and HSV-2 was significantly suppressed in the presence of 25, 50, and 100 μg/mL of Hatay propolis. We found that propolis began to inhibit HSV-1 replication after 24 h of incubation and propolis activity against HSV-2 was found to start at 48 h following incubation. The activity of propolis against both HSV-1 and HSV-2 was confirmed by a significant decrease in the number of viral copies. Conclusions We determined that Hatay propolis samples have important antiviral effects compared with acyclovir. In particular, the synergy produced by antiviral activity of propolis and acyclovir combined had a stronger effect against HSV-1 and HSV-2 than acyclovir alone. PMID:26856414

Oligonucleotides as antivirals: dream or realistic perspective?

PubMed

Van Aerschot, Arthur

2006-09-01

Many reports have been published on antiviral activity of synthetic oligonucleotides, targeted to act either by a true antisense effect or via non-sequence specific interactions. This short review will try to evaluate the current status of the field by focusing on the effects as reported for inhibition of either HSV-1, HCMV or HIV-1. Following an introduction with a historical background and a brief discussion on the different types of constructs and mechanisms of action, the therapeutic potential of antisense oligonucleotides as antivirals, as well as possible pitfalls upon their evaluation will be discussed.

Epigenetic Reprogramming of the Type III Interferon Response Potentiates Antiviral Activity and Suppresses Tumor Growth

PubMed Central

Ding, Siyuan; Khoury-Hanold, William; Iwasaki, Akiko; Robek, Michael D.

2014-01-01

Type III interferon (IFN-λ) exhibits potent antiviral activity similar to IFN-α/β, but in contrast to the ubiquitous expression of the IFN-α/β receptor, the IFN-λ receptor is restricted to cells of epithelial origin. Despite the importance of IFN-λ in tissue-specific antiviral immunity, the molecular mechanisms responsible for this confined receptor expression remain elusive. Here, we demonstrate that the histone deacetylase (HDAC) repression machinery mediates transcriptional silencing of the unique IFN-λ receptor subunit (IFNLR1) in a cell-type-specific manner. Importantly, HDAC inhibitors elevate receptor expression and restore sensitivity to IFN-λ in previously nonresponsive cells, thereby enhancing protection against viral pathogens. In addition, blocking HDAC activity renders nonresponsive cell types susceptible to the pro-apoptotic activity of IFN-λ, revealing the combination of HDAC inhibitors and IFN-λ to be a potential antitumor strategy. These results demonstrate that the type III IFN response may be therapeutically harnessed by epigenetic rewiring of the IFN-λ receptor expression program. PMID:24409098

Ovarian Tumor (OTU)-domain Containing Viral Proteases Evade Ubiquitin- and ISG15-dependent Innate Immune Responses

PubMed Central

Frias-Staheli, Natalia; Giannakopoulos, Nadia V.; Kikkert, Marjolein; Taylor, Shannon L.; Bridgen, Anne; Paragas, Jason J.; Richt, Juergen A.; Rowland, Raymond R.; Schmaljohn, Connie S.; Lenschow, Deborah J.; Snijder, Eric J.; García-Sastre, Adolfo; Virgin, Herbert Whiting

2007-01-01

Summary Ubiquitin (Ub) and interferon stimulated gene product 15 (ISG15) reversibly conjugate to proteins via a conserved LRLRGG C-terminal motif, mediating important innate antiviral responses. The ovarian tumor (OTU) domain represents a superfamily of predicted proteases found in eukaryotic, bacterial and viral proteins, some of which have Ub-deconjugating activity. We show that the OTU domain-containing proteases of nairoviruses and arteriviruses hydrolyze Ub and ISG15 from cellular target proteins. This broad activity contrasts with the target specificity of known mammalian OTU domain-containing proteins. The biological significance of this activity of viral OTU domain-containing proteases was evidenced by their capacity to inhibit NF-κB dependent signaling and to antagonize the antiviral effects of ISG15 during Sindbis virus infection in vivo. The deconjugating activity of viral OTU proteases represents a novel viral immune evasion mechanism that inhibits Ub-and ISG15-dependent antiviral pathways. PMID:18078692

Activation of cGAS-dependent antiviral responses by DNA intercalating agents

PubMed Central

Pépin, Geneviève; Nejad, Charlotte; Thomas, Belinda J.; Ferrand, Jonathan; McArthur, Kate; Bardin, Philip G.; Williams, Bryan R.G.; Gantier, Michael P.

2017-01-01

Acridine dyes, including proflavine and acriflavine, were commonly used as antiseptics before the advent of penicillins in the mid-1940s. While their mode of action on pathogens was originally attributed to their DNA intercalating activity, work in the early 1970s suggested involvement of the host immune responses, characterized by induction of interferon (IFN)-like activities through an unknown mechanism. We demonstrate here that sub-toxic concentrations of a mixture of acriflavine and proflavine instigate a cyclic-GMP-AMP (cGAMP) synthase (cGAS)-dependent type-I IFN antiviral response. This pertains to the capacity of these compounds to induce low level DNA damage and cytoplasmic DNA leakage, resulting in cGAS-dependent cGAMP-like activity. Critically, acriflavine:proflavine pre-treatment of human primary bronchial epithelial cells significantly reduced rhinovirus infection. Collectively, our findings constitute the first evidence that non-toxic DNA binding agents have the capacity to act as indirect agonists of cGAS, to exert potent antiviral effects in mammalian cells. PMID:27694309

Quinoxaline derivatives as new inhibitors of coxsackievirus B5.

PubMed

Carta, Antonio; Sanna, Giuseppina; Briguglio, Irene; Madeddu, Silvia; Vitale, Gabriella; Piras, Sandra; Corona, Paola; Peana, Alessandra Tiziana; Laurini, Erik; Fermeglia, Maurizio; Pricl, Sabrina; Serra, Alessandra; Carta, Elisa; Loddo, Roberta; Giliberti, Gabriele

2018-02-10

Enteroviruses are among the most common and important human pathogens for which there are no specific antiviral agents approved by the US Food and Drug Administration so far. Particularly, coxsackievirus infections have a worldwide distribution and can cause many important diseases. We here report the synthesis of new 14 quinoxaline derivatives and the evaluation of their cytotoxicity and antiviral activity against representatives of ssRNA, dsRNA and dsDNA viruses. Promisingly, three compounds showed a very potent and selective antiviral activity against coxsackievirus B5, with EC 50 in the sub-micromolar range (0.3-0.06 μM). A combination of experimental techniques (i.e. virucidal activity, time of drug addition and adsorption assays) and in silico modeling studies were further performed, aiming to understand the mode of action of the most active, selective and not cytotoxic compound, the ethyl 4-[(2,3-dimethoxyquinoxalin-6-yl)methylthio]benzoate (6). Copyright © 2017 Elsevier Masson SAS. All rights reserved.

An evaluation of the inhibitory effects against rotavirus infection of edible plant extracts

PubMed Central

2012-01-01

Background Rotaviruses are the single most important cause of severe diarrhea in young children worldwide. The developments of specific, potent and accessible antiviral treatments that restrain rotavirus infection remain important to control rotavirus disease. Methods 150 plant extracts with nutritional applications were screened in vitro on MA-104 cells for their antiviral activity against rhesus rotavirus (RRV). One extract (Aspalathus linearis (Burm.f.) R.Dahlgren) was also tested for its effect on the loss of transepithelial resistance (TER) of Caco-2 cells caused by simian rotavirus (SA-11) infection. Results Aqueous extracts of Nelumbo nucifera Gaertn. fruit, Urtica dioica L. root, Aspalathus linearis (Burm.f.) R.Dahlgren leaves, Glycyrrhiza glabra L. root and Olea europaea L. leaves were found to have strong significant antiviral activity with a 50% inhibitory concentration (IC50) < 300 μg/ml. The pure compound 18ß-glycyrrhetinic acid from Glycyrrhiza glabra was found to have the strongest antiviral activity (IC50 46 μM), followed by luteolin and vitexin from Aspalathus linearis (IC50 respectively 116 μM and 129 μM) and apigenin-7-O-glucoside from Melissa officinalis (IC50 150 μM). A combination of Glycyrrhiza glabra L. + Nelumbo nucifera Gaertn. and Urtica dioica L. + Nelumbo nucifera Gaertn. showed synergy in their anti-viral activities. Aspalathus linearis (Burm.f.) R.Dahlgren showed no positive effect on the maintenance of the TER. Conclusions These results indicate that nutritional intervention with extracts of Nelumbo nucifera Gaertn., Aspalathus linearis (Burm.f.) R.Dahlgren, Urtica dioica L., Glycyrrhiza glabra L. and Olea europaea L. might be useful in the treatment of diarrhea caused by rotavirus infection. PMID:22834653

Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

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

Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn

Highlights: • Screening of 50,000 compounds and subsequent lead optimization identified WV970. • WV970 has antiviral effects against influenza A, B and highly pathogenic viral strains. • WV970 inhibits viral genome replication and transcription. • A target database search suggests that WV970 may bind to a number of kinases. • KINOMEscan screening revealed that WV970 has inhibitory effects on 15 kinases. - Abstract: Neuraminidase inhibitors are the only currently available influenza treatment, although resistant viruses to these drugs have already been reported. Thus, new antiviral drugs with novel mechanisms of action are urgently required. In this study, we identified amore » novel antiviral compound, WV970, through cell-based screening of a 50,000 compound library and subsequent lead optimization. This compound exhibited potent antiviral activity with nanomolar IC{sub 50} values against both influenza A and B viruses but not non-influenza RNA viruses. Time-of-addition and indirect immunofluorescence assays indicated that WV970 acted at an early stage of the influenza life cycle, but likely after nuclear entry of viral ribonucleoprotein (vRNP). Further analyses of viral RNA expression and viral polymerase activity indicated that WV970 inhibited vRNP-mediated viral genome replication and transcription. Finally, structure-based virtual screening and comprehensive human kinome screening were used to demonstrate that WV970 acts as a multiple kinase inhibitor, many of which are associated with influenza virus replication. Collectively, these results strongly suggest that WV970 is a promising anti-influenza drug candidate and that several kinases associated with viral replication are promising drug targets.« less

An evaluation of the inhibitory effects against rotavirus infection of edible plant extracts.

PubMed

Knipping, Karen; Garssen, Johan; van't Land, Belinda

2012-07-26

Rotaviruses are the single most important cause of severe diarrhea in young children worldwide. The developments of specific, potent and accessible antiviral treatments that restrain rotavirus infection remain important to control rotavirus disease. 150 plant extracts with nutritional applications were screened in vitro on MA-104 cells for their antiviral activity against rhesus rotavirus (RRV). One extract (Aspalathus linearis (Burm.f.) R.Dahlgren) was also tested for its effect on the loss of transepithelial resistance (TER) of Caco-2 cells caused by simian rotavirus (SA-11) infection. Aqueous extracts of Nelumbo nucifera Gaertn. fruit, Urtica dioica L. root, Aspalathus linearis (Burm.f.) R.Dahlgren leaves, Glycyrrhiza glabra L. root and Olea europaea L. leaves were found to have strong significant antiviral activity with a 50% inhibitory concentration (IC50) < 300 μg/ml. The pure compound 18ß-glycyrrhetinic acid from Glycyrrhiza glabra was found to have the strongest antiviral activity (IC50 46 μM), followed by luteolin and vitexin from Aspalathus linearis (IC50 respectively 116 μM and 129 μM) and apigenin-7-O-glucoside from Melissa officinalis (IC50 150 μM). A combination of Glycyrrhiza glabra L. + Nelumbo nucifera Gaertn. and Urtica dioica L. + Nelumbo nucifera Gaertn. showed synergy in their anti-viral activities. Aspalathus linearis (Burm.f.) R.Dahlgren showed no positive effect on the maintenance of the TER. These results indicate that nutritional intervention with extracts of Nelumbo nucifera Gaertn., Aspalathus linearis (Burm.f.) R.Dahlgren, Urtica dioica L., Glycyrrhiza glabra L. and Olea europaea L. might be useful in the treatment of diarrhea caused by rotavirus infection.

Role of ND10 nuclear bodies in the chromatin repression of HSV-1.

PubMed

Gu, Haidong; Zheng, Yi

2016-04-05

Herpes simplex virus (HSV) is a neurotropic virus that establishes lifelong latent infection in human ganglion sensory neurons. This unique life cycle necessitates an intimate relation between the host defenses and virus counteractions over the long course of infection. Two important aspects of host anti-viral defense, nuclear substructure restriction and epigenetic chromatin regulation, have been intensively studied in the recent years. Upon viral DNA entering the nucleus, components of discrete nuclear bodies termed nuclear domain 10 (ND10), converge at viral DNA and place restrictions on viral gene expression. Meanwhile the infected cell mobilizes its histones and histone-associated repressors to force the viral DNA into nucleosome-like structures and also represses viral transcription. Both anti-viral strategies are negated by various HSV countermeasures. One HSV gene transactivator, infected cell protein 0 (ICP0), is a key player in antagonizing both the ND10 restriction and chromatin repression. On one hand, ICP0 uses its E3 ubiquitin ligase activity to target major ND10 components for proteasome-dependent degradation and thereafter disrupts the ND10 nuclear bodies. On the other hand, ICP0 participates in de-repressing the HSV chromatin by changing histone composition or modification and therefore activates viral transcription. Involvement of a single viral protein in two seemingly different pathways suggests that there is coordination in host anti-viral defense mechanisms and also cooperation in viral counteraction strategies. In this review, we summarize recent advances in understanding the role of chromatin regulation and ND10 dynamics in both lytic and latent HSV infection. We focus on the new observations showing that ND10 nuclear bodies play a critical role in cellular chromatin regulation. We intend to find the connections between the two major anti-viral defense pathways, chromatin remodeling and ND10 structure, in order to achieve a better understanding of how host orchestrates a concerted defense and how HSV adapts with and overcomes the host immunity.

Geraniin extracted from the rind of Nephelium lappaceum binds to dengue virus type-2 envelope protein and inhibits early stage of virus replication.

PubMed

Abdul Ahmad, Siti Aisyah; Palanisamy, Uma D; Tejo, Bimo A; Chew, Miaw Fang; Tham, Hong Wai; Syed Hassan, Sharifah

2017-11-21

The rapid rise and spread in dengue cases, together with the unavailability of safe vaccines and effective antiviral drugs, warrant the need to discover and develop novel anti-dengue treatments. In this study the antiviral activity of geraniin, extracted from the rind of Nephelium lappaceum, against dengue virus type-2 (DENV-2) was investigated. Geraniin was prepared from Nephelium lappaceum rind by reverse phase C-18 column chromatography. Cytotoxicity of geraniin towards Vero cells was evaluated using MTT assay while IC 50 value was determined by plaque reduction assay. The mode-of-action of geraniin was characterized using the virucidal, attachment, penetration and the time-of-addition assays'. Docking experiments with geraniin molecule and the DENV envelope (E) protein was also performed. Finally, recombinant E Domain III (rE-DIII) protein was produced to physiologically test the binding of geraniin to DENV-2 E-DIII protein, through ELISA competitive binding assay. Cytotoxicity assay confirmed that geraniin was not toxic to Vero cells, even at the highest concentration tested. The compound exhibited DENV-2 plaque formation inhibition, with an IC 50 of 1.75 μM. We further revealed that geraniin reduced viral infectivity and inhibited DENV-2 from attaching to the cells but had little effect on its penetration. Geraniin was observed to be most effective when added at the early stage of DENV-2 infection. Docking experiments showed that geraniin binds to DENV E protein, specifically at the DIII region, while the ELISA competitive binding assay confirmed geraniin's interaction with rE-DIII with high affinity. Geraniin from the rind of Nephelium lappaceum has antiviral activity against DENV-2. It is postulated that the compound inhibits viral attachment by binding to the E-DIII protein and interferes with the initial cell-virus interaction. Our results demonstrate that geraniin has the potential to be developed into an effective antiviral treatment, particularly for early phase dengue viral infection.

Robust Protection against Highly Virulent Foot-and-Mouth Disease Virus in Swine by Combination Treatment with Recombinant Adenoviruses Expressing Porcine Alpha and Gamma Interferons and Multiple Small Interfering RNAs

PubMed Central

Park, Jong-Hyeon; Lee, Kwang-Nyeong; Kim, Se-Kyung; You, Su-Hwa; Kim, Taeseong; Tark, Dongseob; Lee, Hyang-Sim; Seo, Min-Goo; Kim, Byounghan

2015-01-01

ABSTRACT Because the currently available vaccines against foot-and-mouth disease (FMD) provide no protection until 4 to 7 days postvaccination, the only alternative method to halt the spread of the FMD virus (FMDV) during outbreaks is the application of antiviral agents. Combination treatment strategies have been used to enhance the efficacy of antiviral agents, and such strategies may be advantageous in overcoming viral mechanisms of resistance to antiviral treatments. We have developed recombinant adenoviruses (Ads) for the simultaneous expression of porcine alpha and gamma interferons (Ad-porcine IFN-αγ) as well as 3 small interfering RNAs (Ad-3siRNA) targeting FMDV mRNAs encoding nonstructural proteins. The antiviral effects of Ad-porcine IFN-αγ and Ad-3siRNA expression were tested in combination in porcine cells, suckling mice, and swine. We observed enhanced antiviral effects in porcine cells and mice as well as robust protection against the highly pathogenic strain O/Andong/SKR/2010 and increased expression of cytokines in swine following combination treatment. In addition, we showed that combination treatment was effective against all serotypes of FMDV. Therefore, we suggest that the combined treatment with Ad-porcine IFN-αγ and Ad-3siRNA may offer fast-acting antiviral protection and be used with a vaccine during the period that the vaccine does not provide protection against FMD. IMPORTANCE The use of current foot-and-mouth disease (FMD) vaccines to induce rapid protection provides limited effectiveness because the protection does not become effective until a minimum of 4 days after vaccination. Therefore, during outbreaks antiviral agents remain the only available treatment to confer rapid protection and reduce the spread of foot-and-mouth disease virus (FMDV) in livestock until vaccine-induced protective immunity can become effective. Interferons (IFNs) and small interfering RNAs (siRNAs) have been reported to be effective antiviral agents against FMDV, although the virus has associated mechanisms of resistance to type I interferons and siRNAs. We have developed recombinant adenoviruses for the simultaneous expression of porcine alpha and gamma interferons (Ad-porcine IFN-αγ) as well as 3 small interfering RNAs (Ad-3siRNA) to enhance the inhibitory effects of these antiviral agents observed in previous studies. Here, we show enhanced antiviral effects against FMDV by combination treatment with Ad-porcine IFN-αγ and Ad-3siRNA to overcome the mechanisms of resistance of FMDV in swine. PMID:26041279

Type I and Type III Interferons Display Different Dependency on Mitogen-Activated Protein Kinases to Mount an Antiviral State in the Human Gut.

PubMed

Pervolaraki, Kalliopi; Stanifer, Megan L; Münchau, Stephanie; Renn, Lynnsey A; Albrecht, Dorothee; Kurzhals, Stefan; Senís, Elena; Grimm, Dirk; Schröder-Braunstein, Jutta; Rabin, Ronald L; Boulant, Steeve

2017-01-01

Intestinal epithelial cells (IECs) are constantly exposed to commensal flora and pathogen challenges. How IECs regulate their innate immune response to maintain gut homeostasis remains unclear. Interferons (IFNs) are cytokines produced during infections. While type I IFN receptors are ubiquitously expressed, type III IFN receptors are expressed only on epithelial cells. This epithelium specificity strongly suggests exclusive functions at epithelial surfaces, but the relative roles of type I and III IFNs in the establishment of an antiviral innate immune response in human IECs are not clearly defined. Here, we used mini-gut organoids to define the functions of types I and III IFNs to protect the human gut against viral infection. We show that primary non-transformed human IECs, upon viral challenge, upregulate the expression of both type I and type III IFNs at the transcriptional level but only secrete type III IFN in the supernatant. However, human IECs respond to both type I and type III IFNs by producing IFN-stimulated genes that in turn induce an antiviral state. Using genetic ablation of either type I or type III IFN receptors, we show that either IFN can independently restrict virus infection in human IECs. Importantly, we report, for the first time, differences in the mechanisms by which each IFN establishes the antiviral state. Contrary to type I IFN, the antiviral activity induced by type III IFN is strongly dependent on the mitogen-activated protein kinases signaling pathway, suggesting a pathway used by type III IFNs that non-redundantly contributes to the antiviral state. In conclusion, we demonstrate that human intestinal epithelial cells specifically regulate their innate immune response favoring type III IFN-mediated signaling, which allows for efficient protection against pathogens without producing excessive inflammation. Our results strongly suggest that type III IFN constitutes the frontline of antiviral response in the human gut. We propose that mucosal surfaces, particularly the gastrointestinal tract, have evolved to favor type III IFN-mediated response to pathogen infections as it allows for spatial segregation of signaling and moderate production of inflammatory signals which we propose are key to maintain gut homeostasis.

Broad-spectrum non-nucleoside inhibitors for caliciviruses.

PubMed

Netzler, Natalie E; Enosi Tuipulotu, Daniel; Eltahla, Auda A; Lun, Jennifer H; Ferla, Salvatore; Brancale, Andrea; Urakova, Nadya; Frese, Michael; Strive, Tanja; Mackenzie, Jason M; White, Peter A

2017-10-01

Viruses of the Caliciviridae cause significant and sometimes lethal diseases, however despite substantial research efforts, specific antivirals are lacking. Broad-spectrum antivirals could combat multiple viral pathogens, offering a rapid solution when no therapies exist. The RNA-dependent RNA polymerase (RdRp) is an attractive antiviral target as it is essential for viral replication and lacks mammalian homologs. To focus the search for pan-Caliciviridae antivirals, the RdRp was probed with non-nucleoside inhibitors (NNIs) developed against hepatitis C virus (HCV) to reveal both allosteric ligands for structure-activity relationship enhancement, and highly-conserved RdRp pockets for antiviral targeting. The ability of HCV NNIs to inhibit calicivirus RdRp activities was assessed using in vitro enzyme and murine norovirus cell culture assays. Results revealed that three NNIs which bound the HCV RdRp Thumb I (TI) site also inhibited transcriptional activities of six RdRps spanning the Norovirus, Sapovirus and Lagovirus genera of the Caliciviridae. These NNIs included JTK-109 (RdRp inhibition range: IC 50 4.3-16.6 μM), TMC-647055 (IC 50 range: 18.8-45.4 μM) and Beclabuvir (IC 50 range: 23.8->100 μM). In silico studies and site-directed mutagenesis indicated the JTK-109 binding site was within the calicivirus RdRp thumb domain, in a pocket termed Site-B, which is highly-conserved within all calicivirus RdRps. Additionally, RdRp inhibition assays revealed that JTK-109 was antagonistic with the previously reported RdRp inhibitor pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4',8'-disulfonate) tetrasodium salt (PPNDS), that also binds to Site-B. Moreover, like JTK-109, PPNDS was also a potent inhibitor of polymerases from six viruses spanning the three Caliciviridae genera tested (IC 50 range: 0.1-2.3 μM). Together, this study demonstrates the potential for de novo development of broad-spectrum antivirals that target the highly-conserved RdRp thumb pocket, Site-B. We also revealed three broad-spectrum HCV NNIs that could be used as antiviral scaffolds for further development against caliciviruses and other viruses. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibition of p38 mitogen-activated protein kinase impairs influenza virus-induced primary and secondary host gene responses and protects mice from lethal H5N1 infection.

PubMed

Börgeling, Yvonne; Schmolke, Mirco; Viemann, Dorothee; Nordhoff, Carolin; Roth, Johannes; Ludwig, Stephan

2014-01-03

Highly pathogenic avian influenza viruses (HPAIV) induce severe inflammation in poultry and men. One characteristic of HPAIV infections is the induction of a cytokine burst that strongly contributes to viral pathogenicity. This cell-intrinsic hypercytokinemia seems to involve hyperinduction of p38 mitogen-activated protein kinase. Here we investigate the role of p38 MAPK signaling in the antiviral response against HPAIV in mice as well as in human endothelial cells, the latter being a primary source of cytokines during systemic infections. Global gene expression profiling of HPAIV-infected endothelial cells in the presence of the p38-specific inhibitor SB 202190 revealed that inhibition of p38 MAPK leads to reduced expression of IFNβ and other cytokines after H5N1 and H7N7 infection. More than 90% of all virus-induced genes were either partially or fully dependent on p38 signaling. Moreover, promoter analysis confirmed a direct impact of p38 on the IFNβ promoter activity. Furthermore, upon treatment with IFN or conditioned media from HPAIV-infected cells, p38 controls interferon-stimulated gene expression by coregulating STAT1 by phosphorylation at serine 727. In vivo inhibition of p38 MAPK greatly diminishes virus-induced cytokine expression concomitant with reduced viral titers, thereby protecting mice from lethal infection. These observations show that p38 MAPK acts on two levels of the antiviral IFN response. Initially the kinase regulates IFN induction and, at a later stage, p38 controls IFN signaling and thereby expression of IFN-stimulated genes. Thus, inhibition of MAP kinase p38 may be an antiviral strategy that protects mice from lethal influenza by suppressing excessive cytokine expression.

Heartland virus NSs protein disrupts host defenses by blocking the TBK1 kinase-IRF3 transcription factor interaction and signaling required for interferon induction.

PubMed

Ning, Yun-Jia; Feng, Kuan; Min, Yuan-Qin; Deng, Fei; Hu, Zhihong; Wang, Hualin

2017-10-06

Heartland virus (HRTV) is a pathogenic phlebovirus related to the severe fever with thrombocytopenia syndrome virus (SFTSV), another phlebovirus causing life-threatening disease in humans. Previous findings have suggested that SFTSV can antagonize the host interferon (IFN) system via viral nonstructural protein (NSs)-mediated sequestration of antiviral signaling proteins into NSs-induced inclusion bodies. However, whether and how HRTV counteracts the host innate immunity is unknown. Here, we report that HRTV NSs (HNSs) also antagonizes IFN and cytokine induction and bolsters viral replication, although no noticeable inclusion body formation was observed in HNSs-expressing cells. Furthermore, HNSs inhibited the virus-triggered activation of IFN-β promoter by specifically targeting the IFN-stimulated response element but not the NF-κB response element. Consistently, HNSs blocked the phosphorylation and nuclear translocation of IFN regulatory factor 3 (IRF3, an IFN-stimulated response element-activating transcription factor). Reporter gene assays next showed that HNSs blockades the antiviral signaling mediated by RIG-I-like receptors likely at the level of TANK-binding kinase 1 (TBK1). Indeed, HNSs strongly interacts with TBK1 as indicated by confocal microscopy and pulldown analyses, and we also noted that the scaffold dimerization domain of TBK1 is required for the TBK1-HNSs interaction. Finally, pulldown assays demonstrated that HNSs expression dose-dependently diminishes a TBK1-IRF3 interaction, further explaining the mechanism for HNSs function. Collectively, these data suggest that HNSs, an antagonist of host innate immunity, interacts with TBK1 and thereby hinders the association of TBK1 with its substrate IRF3, thus blocking IRF3 activation and transcriptional induction of the cellular antiviral responses. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Characterization of vaniprevir, a hepatitis C virus NS3/4A protease inhibitor, in patients with HCV genotype 1 infection: safety, antiviral activity, resistance, and pharmacokinetics.

PubMed

Lawitz, Eric; Sulkowski, Mark; Jacobson, Ira; Kraft, Walter K; Maliakkal, Benedict; Al-Ibrahim, Mohamed; Gordon, Stuart C; Kwo, Paul; Rockstroh, Juergen Kurt; Panorchan, Paul; Miller, Michelle; Caro, Luzelena; Barnard, Richard; Hwang, Peggy May; Gress, Jacqueline; Quirk, Erin; Mobashery, Niloufar

2013-09-01

Vaniprevir is a competitive inhibitor of the hepatitis C virus (HCV) NS3/4A protease that has potent anti-HCV activity in preclinical models. This placebo-controlled dose-ranging study assessed the safety, tolerability, and antiviral efficacy of vaniprevir monotherapy in patients with genotype 1 chronic HCV infection. Treatment-naive and treatment-experienced non-cirrhotic adult patients with baseline HCV RNA >10(6)IU/ml were randomized to receive placebo or vaniprevir at doses of 125 mg qd, 600 mg qd, 25mg bid, 75 mg bid, 250 mg bid, 500 mg bid, and 700 mg bid for 8 days. Forty patients (82.5% male, 75% genotype 1a) received at least one dose of placebo or vaniprevir. After 1 week of vaniprevir, the decrease in HCV RNA from baseline ranged from 1.8 to 4.6 log₁₀IU/ml across all treatment groups, and there was a greater than dose-proportional increase in vaniprevir exposure at doses above 75 mg bid. The most commonly reported drug-related adverse events (AEs) were diarrhea (n=5) and nausea (n=5). No pattern of laboratory or ECG abnormalities was observed, all AEs resolved during the study, and there were no discontinuations due to AEs. No serious AEs were reported. Resistance-associated amino acid variants were identified at positions R155 and D168 in patients infected with genotype 1a virus. Vaniprevir monotherapy demonstrated potent antiviral activity in patients with chronic genotype 1 HCV infection, and was generally well tolerated with no serious AEs or discontinuations due to AEs. Further development of vaniprevir, including studies in combination with other anti-HCV agents, is ongoing. Copyright © 2013 Elsevier B.V. All rights reserved.

Direct-acting antiviral therapy decreases hepatocellular carcinoma recurrence rate in cirrhotic patients with chronic hepatitis C.

PubMed

Virlogeux, Victor; Pradat, Pierre; Hartig-Lavie, Kerstin; Bailly, François; Maynard, Marianne; Ouziel, Guillaume; Poinsot, Domitille; Lebossé, Fanny; Ecochard, Marie; Radenne, Sylvie; Benmakhlouf, Samir; Koffi, Joseph; Lack, Philippe; Scholtes, Caroline; Uhres, Anne-Claire; Ducerf, Christian; Mabrut, Jean-Yves; Rode, Agnès; Levrero, Massimo; Combet, Christophe; Merle, Philippe; Zoulim, Fabien

2017-08-01

Arrival of direct-acting antiviral agents against hepatitis C virus with high-sustained virological response rates and very few side effects has drastically changed the management of hepatitis C virus infection. The impact of direct-acting antiviral exposure on hepatocellular carcinoma recurrence after a first remission in patients with advanced fibrosis remains to be clarified. 68 consecutive hepatitis C virus patients with a first hepatocellular carcinoma diagnosis and under remission, subsequently treated or not with a direct-acting antiviral combination, were included. Clinical, biological and virological data were collected at first hepatocellular carcinoma diagnosis, at remission and during the surveillance period. All patients were cirrhotic. Median age was 62 years and 76% of patients were male. Twenty-three patients (34%) were treated with direct-acting antivirals and 96% of them achieved sustained virological response. Median time between hepatocellular carcinoma remission and direct-acting antivirals initiation was 7.2 months (IQR: 3.6-13.5; range: 0.3-71.4) and median time between direct-acting antivirals start and hepatocellular carcinoma recurrence was 13.0 months (IQR: 9.2-19.6; range: 3.0-24.7). Recurrence rate was 1.7/100 person-months among treated patients vs 4.2/100 person-months among untreated patients (P=.008). In multivariate survival analysis, the hazard ratio for hepatocellular carcinoma recurrence after direct-acting antivirals exposure was 0.24 (95% confidence interval: 0.10-0.55; P<.001). Hepatocellular carcinoma recurrence rate was significantly lower among patients treated with direct-acting antivirals compared with untreated patients. Given the potential impact of our observation, large-scale prospective cohort studies are needed to confirm these results. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Inhibition of hepatitis B viral entry by nucleic acid polymers in HepaRG cells and primary human hepatocytes.

PubMed

Guillot, Clément; Martel, Nora; Berby, Françoise; Bordes, Isabelle; Hantz, Olivier; Blanchet, Matthieu; Sureau, Camille; Vaillant, Andrew; Chemin, Isabelle

2017-01-01

Hepatitis B virus (HBV) infection remains a major public health concern worldwide with 240 million individuals chronically infected and at risk of developing cirrhosis and hepatocellular carcinoma. Current treatments rarely cure chronic hepatitis B infection, highlighting the need for new anti-HBV drugs. Nucleic acid polymers (NAPs) are phosphorothioated oligonucleotides that have demonstrated a great potential to inhibit infection with several viruses. In chronically infected human patients, NAPs administration lead to a decline of blood HBsAg and HBV DNA and to HBsAg seroconversion, the expected signs of functional cure. NAPs have also been shown to prevent infection of duck hepatocytes with the Avihepadnavirus duck hepatitis B virus (DHBV) and to exert an antiviral activity against established DHBV infection in vitro and in vivo. In this study, we investigated the specific anti-HBV antiviral activity of NAPs in the HepaRG human hepatoma cell line and primary cultures of human hepatocytes. NAPs with different chemical features (phosphorothioation, 2'O-methyl ribose, 5-methylcytidine) were assessed for antiviral activity when provided at the time of HBV inoculation or post-inoculation. NAPs dose-dependently inhibited HBV entry in a phosphorothioation-dependent, sequence-independent and size-dependent manner. This inhibition of HBV entry by NAPs was impaired by 2'O-methyl ribose modification. NAP treatment after viral inoculation did not elicit any antiviral activity.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes.

PubMed

Kubiça, Thaís F; Alves, Sydney H; Weiblen, Rudi; Lovato, Luciane T

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL(-1)) and 1,8-cineole (CC50 = 2996.10 μg mL(-1)) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.

Antiviral activity of human oligoadenylate synthetases-like (OASL) is mediated by enhancing retinoic acid-inducible gene I (RIG-I) signaling

PubMed Central

Zhu, Jianzhong; Zhang, Yugen; Ghosh, Arundhati; Cuevas, Rolando A.; Forero, Adriana; Dhar, Jayeeta; Ibsen, Mikkel Søes; Schmid-Burgk, Jonathan Leo; Schmidt, Tobias; Ganapathiraju, Madhavi K.; Fujita, Takashi; Hartmann, Rune; Barik, Sailen; Hornung, Veit; Coyne, Carolyn B.; Sarkar, Saumendra N.

2014-01-01

SUMMARY Virus infection is sensed in the cytoplasm by retinoic acid-inducible gene I (RIG-I, also known as DDX58), which requires RNA and polyubiquitin binding to induce type I interferon (IFN), and activate cellular innate immunity. We show that the human IFN-inducible oligoadenylate synthetases-like (OASL) protein had antiviral activity and mediated RIG-I activation by mimicking polyubiquitin. Loss of OASL expression reduced RIG-I signaling and enhanced virus replication in human cells. Conversely, OASL expression suppressed replication of a number of viruses in a RIG-I-dependent manner and enhanced RIG-I-mediated IFN induction. OASL interacted and colocalized with RIG-I, and through its C-terminal ubiquitin-like domain specifically enhanced RIG-I signaling. Bone marrow derived macrophages from mice deficient for Oasl2 showed that among the two mouse orthologs of human OASL; Oasl2 is functionally similar to human OASL. Our findings show a mechanism by which human OASL contributes to host antiviral responses by enhancing RIG-I activation. PMID:24931123

Proteolytic activation of the SARS-coronavirus spike protein: cutting enzymes at the cutting edge of antiviral research.

PubMed

Simmons, Graham; Zmora, Pawel; Gierer, Stefanie; Heurich, Adeline; Pöhlmann, Stefan

2013-12-01

The severe acute respiratory syndrome (SARS) pandemic revealed that zoonotic transmission of animal coronaviruses (CoV) to humans poses a significant threat to public health and warrants surveillance and the development of countermeasures. The activity of host cell proteases, which cleave and activate the SARS-CoV spike (S) protein, is essential for viral infectivity and constitutes a target for intervention. However, the identities of the proteases involved have been unclear. Pioneer studies identified cathepsins and type II transmembrane serine proteases as cellular activators of SARS-CoV and demonstrated that several emerging viruses might exploit these enzymes to promote their spread. Here, we will review the proteolytic systems hijacked by SARS-CoV for S protein activation, we will discuss their contribution to viral spread in the host and we will outline antiviral strategies targeting these enzymes. This paper forms part of a series of invited articles in Antiviral Research on "From SARS to MERS: 10years of research on highly pathogenic human coronaviruses.'' Copyright © 2013 Elsevier B.V. All rights reserved.

Anti-influenza M2e antibody

DOEpatents

Bradbury, Andrew M.

2013-04-16

Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

Anti-influenza M2e antibody

DOEpatents

Bradbury, Andrew M [Santa Fe, NM

2011-12-20

Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

Structural Optimizations of Thieno[3,2-b]pyrrole Derivatives for the Development of Metabolically Stable Inhibitors of Chikungunya Virus.

PubMed

Ching, Kuan-Chieh; Tran, Thi Ngoc Quy; Amrun, Siti Naqiah; Kam, Yiu-Wing; Ng, Lisa F P; Chai, Christina L L

2017-04-13

Chikungunya virus (CHIKV) is a re-emerging vector-borne alphavirus, and there is no approved effective antiviral treatment currently available for CHIKV. We previously reported the discovery of thieno[3,2-b]pyrrole 1b that displayed good antiviral activity against CHIKV infection in vitro. However, it has a short half-life in the presence of human liver microsomes (HLMs) (T 1/2 = 2.91 min). Herein, we report further optimization studies in which potential metabolically labile sites on compound 1b were removed or modified, resulting in the identification of thieno[3,2-b]pyrrole 20 and pyrrolo[2,3-d]thiazole 23c possessing up to 17-fold increase in metabolic half-lives in HLMs and good in vivo pharmacokinetic properties. Compound 20 not only attenuated viral RNA production and displayed broad-spectrum antiviral activity against other alphaviruses and CHIKV isolates but also exhibited limited cytotoxic liability (CC 50 > 100 μM). These studies have identified two compounds that have the potential for further development as antiviral drugs against CHIKV infection.

Antiviral Efficacy of Verdinexor In Vivo in Two Animal Models of Influenza A Virus Infection

PubMed Central

Perwitasari, Olivia; Johnson, Scott; Yan, Xiuzhen; Register, Emery; Crabtree, Jackelyn; Gabbard, Jon; Howerth, Elizabeth; Shacham, Sharon; Carlson, Robert; Tamir, Sharon; Tripp, Ralph A.

2016-01-01

Influenza A virus (IAV) causes seasonal epidemics of respiratory illness that can cause mild to severe illness and potentially death. Antiviral drugs are an important countermeasure against IAV; however, drug resistance has developed, thus new therapeutic approaches are being sought. Previously, we demonstrated the antiviral activity of a novel nuclear export inhibitor drug, verdinexor, to reduce influenza replication in vitro and pulmonary virus burden in mice. In this study, in vivo efficacy of verdinexor was further evaluated in two animal models or influenza virus infection, mice and ferrets. In mice, verdinexor was efficacious to limit virus shedding, reduce pulmonary pro-inflammatory cytokine expression, and moderate leukocyte infiltration into the bronchoalveolar space. Similarly, verdinexor-treated ferrets had reduced lung pathology, virus burden, and inflammatory cytokine expression in the nasal wash exudate. These findings support the anti-viral efficacy of verdinexor, and warrant its development as a novel antiviral therapeutic for influenza infection. PMID:27893810

Antiviral Effects of Small Interfering RNA Simultaneously Inducing RNA Interference and Type 1 Interferon in Coxsackievirus Myocarditis

PubMed Central

Ahn, Jeonghyun; Ko, Ara; Jun, Eun Jung; Won, Minah; Kim, Yoo Kyum; Ju, Eun-Seon

2012-01-01

Antiviral therapeutics are currently unavailable for treatment of coxsackievirus B3, which can cause life-threatening myocarditis. A modified small interfering RNA (siRNA) containing 5′-triphosphate, 3p-siRNA, was shown to induce RNA interference and interferon activation. We aimed to develop a potent antiviral treatment using CVB3-specific 3p-siRNA and to understand its underlying mechanisms. Virus-specific 3p-siRNA was superior to both conventional virus-specific siRNA with an empty hydroxyl group at the 5′ end (OH-siRNA) and nonspecific 3p-siRNA in decreasing viral replication and subsequent cytotoxicity. A single administration of 3p-siRNA dramatically attenuated virus-associated pathological symptoms in mice with no signs of toxicity, and their body weights eventually reached the normal range. Myocardial inflammation and fibrosis were rare, and virus production was greatly reduced. A nonspecific 3p-siRNA showed relatively less protective effect under identical conditions, and a virus-specific OH-siRNA showed no protective effects. We confirmed that virus-specific 3p-siRNA simultaneously activated target-specific gene silencing and type I interferon signaling. We provide a clear proof of concept that coxsackievirus B3-specific 3p-siRNA has 2 distinct modes of action, which significantly enhance antiviral activities with minimal organ damage. This is the first direct demonstration of improved antiviral effects with an immunostimulatory virus-specific siRNA in coxsackievirus myocarditis, and this method could be applied to many virus-related diseases. PMID:22508300

Induction and suppression of antiviral RNA interference by influenza A virus in mammalian cells.

PubMed

Li, Yang; Basavappa, Megha; Lu, Jinfeng; Dong, Shuwei; Cronkite, D Alexander; Prior, John T; Reinecker, Hans-Christian; Hertzog, Paul; Han, Yanhong; Li, Wan-Xiang; Cheloufi, Sihem; Karginov, Fedor V; Ding, Shou-Wei; Jeffrey, Kate L

2016-12-05

Influenza A virus (IAV) causes annual epidemics and occasional pandemics, and is one of the best-characterized human RNA viral pathogens 1 . However, a physiologically relevant role for the RNA interference (RNAi) suppressor activity of the IAV non-structural protein 1 (NS1), reported over a decade ago 2 , remains unknown 3 . Plant and insect viruses have evolved diverse virulence proteins to suppress RNAi as their hosts produce virus-derived small interfering RNAs (siRNAs) that direct specific antiviral defence 4-7 by an RNAi mechanism dependent on the slicing activity of Argonaute proteins (AGOs) 8,9 . Recent studies have documented induction and suppression of antiviral RNAi in mouse embryonic stem cells and suckling mice 10,11 . However, it is still under debate whether infection by IAV or any other RNA virus that infects humans induces and/or suppresses antiviral RNAi in mature mammalian somatic cells 12-21 . Here, we demonstrate that mature human somatic cells produce abundant virus-derived siRNAs co-immunoprecipitated with AGOs in response to IAV infection. We show that the biogenesis of viral siRNAs from IAV double-stranded RNA (dsRNA) precursors in infected cells is mediated by wild-type human Dicer and potently suppressed by both NS1 of IAV as well as virion protein 35 (VP35) of Ebola and Marburg filoviruses. We further demonstrate that the slicing catalytic activity of AGO2 inhibits IAV and other RNA viruses in mature mammalian cells, in an interferon-independent fashion. Altogether, our work shows that IAV infection induces and suppresses antiviral RNAi in differentiated mammalian somatic cells.

Structure-based lead optimization to improve antiviral potency and ADMET properties of phenyl-1H-pyrrole-carboxamide entry inhibitors targeted to HIV-1 gp120.

PubMed

Curreli, Francesca; Belov, Dmitry S; Kwon, Young Do; Ramesh, Ranjith; Furimsky, Anna M; O'Loughlin, Kathleen; Byrge, Patricia C; Iyer, Lalitha V; Mirsalis, Jon C; Kurkin, Alexander V; Altieri, Andrea; Debnath, Asim K

2018-05-12

We are continuing our concerted effort to optimize our first lead entry antagonist, NBD-11021, which targets the Phe43 cavity of the HIV-1 envelope glycoprotein gp120, to improve antiviral potency and ADMET properties. In this report, we present a structure-based approach that helped us to generate working hypotheses to modify further a recently reported advanced lead entry antagonist, NBD-14107, which showed significant improvement in antiviral potency when tested in a single-cycle assay against a large panel of Env-pseudotyped viruses. We report here the synthesis of twenty-nine new compounds and evaluation of their antiviral activity in a single-cycle and multi-cycle assay to derive a comprehensive structure-activity relationship (SAR). We have selected three inhibitors with the high selectivity index for testing against a large panel of 55 Env-pseudotyped viruses representing a diverse set of clinical isolates of different subtypes. The antiviral activity of one of these potent inhibitors, 55 (NBD-14189), against some clinical isolates was as low as 63 nM. We determined the sensitivity of CD4-binding site mutated-pseudoviruses to these inhibitors to confirm that they target HIV-1 gp120. Furthermore, we assessed their ADMET properties and compared them to the clinical candidate attachment inhibitor, BMS-626529. The ADMET data indicate that some of these new inhibitors have comparable ADMET properties to BMS-626529 and can be optimized further to potential clinical candidates. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

An index of the ratio of inflammatory to antiviral cell types mediates the effects of social adversity and age on chronic illness.

PubMed

Simons, Ronald L; Lei, Man-Kit; Beach, Steven R H; Barr, Ashley B; Cutrona, Carolyn E; Gibbons, Frederick X; Philibert, Robert A

2017-07-01

It is assumed that both social stress and chronological age increase the risk of chronic illness, in part, through their effect on systemic inflammation. Unfortunately, observational studies usually employ single-marker measures of inflammation (e.g., Interleukin-6, C-reactive protein) that preclude strong tests for mediational effects. The present study investigated the extent to which the effects of socioeconomic disadvantage and age on onset of chronic illness is mediated by dominance of the innate (inflammatory) over the acquired (antiviral) components of the immune system. We assessed inflammation using the ratio of inflammatory to antiviral cell types (ITACT Ratio). This approach provided a stronger test of evolutionary arguments regarding the effect of social stress on chronic inflammation than is the case with cytokine measures, and afforded an opportunity to replicate findings obtained utilizing mRNA. We used structural equation modeling and longitudinal data from a sample of 100 middle-age African American women to perform our analyses. Dominance of inflammatory over antiviral cell activity was associated with each of the eight illnesses included in our chronic illness measure. Both socioeconomic disadvantage and age were also associated with inflammatory dominance. Pursuant to the central focus of the study, the effects of socioeconomic adversity and age on increased illness were mediated by our measure of inflammatory dominance. The indirect effect of these variables through inflammatory cell profile was significant, with neither socioeconomic disadvantage nor age showing a significant association with illness once the impact of inflammatory cell profile was taken into account. First, the analysis provides preliminary validation of a new measure of inflammation that is calculated based on the ratio of inflammatory to antiviral white blood cells. Second, our results support the hypothesis that socioeconomic disadvantage and chronological age increase risk for chronic illness in part through their effect on inflammatory processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antiviral Therapy in Steroid-refractory Ulcerative Colitis with Cytomegalovirus: Systematic Review and Meta-analysis.

PubMed

Shukla, Tushar; Singh, Siddharth; Loftus, Edward V; Bruining, David H; McCurdy, Jeffrey D

2015-11-01

The role of antiviral therapy in patients with ulcerative colitis (UC) with cytomegalovirus (CMV) remains unclear. We therefore performed a systematic review and meta-analysis to assess the association between antiviral therapy and the risk of colectomy. Multiple electronic databases were searched systematically through July 2014 for studies reporting the risk of colectomy in patients with UC with CMV stratified by treatment with antiviral agents. Colectomy rates were assessed for the overall cohort and stratified by corticosteroid (CS) refractoriness. We estimated summary odds ratios and 95% confidence intervals, using random-effects model, and used Grading of Recommendations Assessment, Development, and Evaluation criteria to appraise the quality of evidence. Fifteen observational studies (333 patients with UC with CMV, 43.2% treated with antiviral agents) were identified, of which 8 stratified patients according to CS-refractory disease (55.4% treated with antiviral agents). Antiviral therapy resulted in a significantly lower risk of colectomy in patients with CS-refractory disease (odds ratio, 0.20; 95% confidence interval, 0.08-0.49; I = 0%) but not in the overall population of patients with UC (odds ratio, 0.92; 95% confidence interval, 0.31-2.76; I = 65). The quality evidence was low. The results were stable when restricting the analysis to patients with a tissue diagnosis of CMV and studies that defined CS-refractory disease as a failure to respond to intravenous CS. Antiviral therapy may benefit a subgroup of patients with UC who are refractory to CS. Further prospective trials are required to confirm these findings.

Bovine κ-casein inhibits human rotavirus (HRV) infection via direct binding of glycans to HRV.

PubMed

Inagaki, M; Muranishi, H; Yamada, K; Kakehi, K; Uchida, K; Suzuki, T; Yabe, T; Nakagomi, T; Nakagomi, O; Kanamaru, Y

2014-05-01

Human rotavirus (HRV) is a major etiologic agent of severe infantile gastroenteritis. κ-Casein (κ-CN) from both human and bovine mature milk has been reported to have anti-HRV activity; however, the mechanism of this activity is poorly understood. The present study examined the molecular basis for the protective effect of bovine κ-CN derived from late colostrum (6-7 d after parturition) and from mature milk. Among the components of casein, κ-CN is the only glycosylated protein that has been identified. Therefore, we investigated whether the glycan residues in κ-CN were involved in the anti-HRV activity. Desialylated CN obtained by neuraminidase treatment exhibited anti-HRV activity, whereas deglycosylated CN obtained by o-glycosidase treatment lacked antiviral activity, indicating that glycans were responsible for the antiviral activity of CN. Furthermore, an evanescent-field fluorescence-assisted assay showed that HRV particles directly bound to heated casein (at 95°C for 30 min) in a viral titer-dependent manner. Although the heated κ-CN retained inhibitory activity in a neutralization assay, the activity was weaker than that observed before heat treatment. Our findings indicate that the inhibitory mechanism of bovine κ-CN against HRV involves direct binding to viral particles via glycan residues. In addition, heat-labile structures in κ-CN may play an important role in maintenance of κ-CN binding to HRV. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Antiviral Defense Involves AGO4 in an Arabidopsis-Potexvirus Interaction.

PubMed

Brosseau, Chantal; El Oirdi, Mohamed; Adurogbangba, Ayooluwa; Ma, Xiaofang; Moffett, Peter

2016-11-01

In plants, RNA silencing regulates gene expression through the action of Dicer-like (DCL) and Argonaute (AGO) proteins via micro RNAs and RNA-dependent DNA methylation (RdDM). In addition, RNA silencing functions as an antiviral defense mechanism by targeting virus-derived double-stranded RNA. Plants encode multiple AGO proteins with specialized functions, including AGO4-like proteins that affect RdDM and AGO2, AGO5, and AGO1, which have antiviral activities. Here, we show that AGO4 is also required for defense against the potexvirus Plantago asiatica mosaic virus (PlAMV), most likely independent of RdDM components such as DCL3, Pol IV, and Pol V. Transient assays showed that AGO4 has direct antiviral activity on PlAMV and, unlike RdDM, this activity does not require nuclear localization of AGO4. Furthermore, although PlAMV infection causes a decrease in AGO4 expression, PlAMV causes a change in AGO4 localization from a largely nuclear to a largely cytoplasmic distribution. These results indicate an important role for AGO4 in targeting plant RNA viruses as well as demonstrating novel mechanisms of regulation of and by AGO4, independent of its canonical role in regulating gene expression by RdDM.

Expression, purification and characterisation of recombinant Escherichia coli derived chicken interleukin-12.

PubMed

Thomas, Jesse D; Morris, Kirsten R; Godfrey, Dale I; Lowenthal, John W; Bean, Andrew G D

2008-12-15

Zoonotic viruses, such as H5N1 Avian Influenza, pose major threats to both animals and humans, and with this in mind there is a need for the development of new anti-viral strategies. The cytokine interleukin-12 (IL-12) is known to play a pivotal regulatory role in the anti-viral response due to its role in the induction of the key anti-viral cytokine IFN-gamma. Therefore, strategies which provide a means for the production of therapeutic quantities of IL-12 may be of major benefit. Here we describe the development of biologically active Escherichia coli (E. coli) derived chicken IL-12 (ChIL-12). The single chain ChIL-12 gene was cloned into the pET32b expression vector, transformed into the BL-21 E. coli strain and expression induced with IPTG. Over expressed protein was solubilised with zwittergent detergent and isolated utilising Nickel ion affinity chromatography. Biological activity was determined as ChIL-12 stimulated proliferation of pre-treated T-cells in vitro. This study is the first example of a biologically active E. coli derived IL-12 from a non-mammalian vertebrate subsequently providing a means for testing the anti-viral therapeutic potential of ChIL-12 in an in vivo model.

[Impact of Delivery Method on Antiviral Activity of Phosphodiester, Phosphorothioate, and Phosphoryl Guanidine Oligonucleotides in MDCK Cells Infected with H5N1 Bird Flu Virus].

PubMed

Levina, A S; Repkova, M N; Chelobanov, B P; Bessudnova, E V; Mazurkova, N A; Stetsenko, D A; Zarytova, V F

2017-01-01

We have previously described nanocomposites containing conjugates or complexes of native oligodeoxyribonucleotides with poly-L-lysine and TiO2 nanoparticles. We have shown that these nanocomposites efficiently suppressed influenza A virus reproduction in MDCK cells. Here, we have synthesized previously undescribed nanocomposites that consist of TiO2 nanoparticles and polylysine conjugates with oligonucleotides that contain phosphoryl guanidine or phosphorothioate internucleotide groups. These nanocomposites have been shown to exhibit antiviral activity in MDCK cells infected with H5N1 influenza A virus. The nanocomposites containing phosphorothioate oligonucleotides inhibited virus replication ~130-fold. More potent inhibition, i.e., ~5000-fold or ~4600-fold, has been demonstrated by nanocomposites that contain phosphoryl guanidine or phosphodiester oligonucleotides, respectively. Free oligonucleotides have been nearly inactive. The antiviral activity of oligonucleotides of all three types, when delivered by Lipofectamine, has been significantly lower compared to the oligonucleotides delivered in the nanocomposites. In the former case, the phosphoryl guanidine oligonucleotide has appeared to be the most efficient; it has inhibited the virus replication by a factor of 400. The results make it possible to consider phosphoryl guanidine oligonucleotides, along with other oligonucleotide derivatives, as potential antiviral agents against H5N1 avian flu virus.

Antiviral effect of emodin from Rheum palmatum against coxsakievirus B5 and human respiratory syncytial virus in vitro.

PubMed

Liu, Zhao; Ma, Nian; Zhong, Yan; Yang, Zhan-qiu

2015-12-01

Viral infections are the major causes of morbidity and mortality in elderly people and young children throughout the world. The most common pathogens include coxsackie virus (CV) and respiratory syncytial virus (RSV). However, no antiviral agents with low toxicity and drug resistance are currently available in clinic therapy. The present study aimed to examine the antiviral activities of emodin (an ingredient of Rheum palmatum) against CVB5 and RSV infections, in an attempt to discover new antiviral agents for virus infection. The monomer emodin was extracted and isolated from Rheum palmatum. The antiviral activities of emodin on HEp-2 cells were evaluated, including virus replication inhibition, virucidal and anti-absorption effects, by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tet-razolium bromide (MTT) assay and plaque reduction assay (PRA). The kinetics of virus inhibition by emodin in a period of 14 h was further determined by plaque assay and quantitative real time PCR (qPCR). Cytokine (IFN-γ, TNF-α) mRNA expressions after emodin treatment (7.5, 15, 30 μmol/L) were also assessed by qPCR post-infection. The results showed that emodin had potent inhibitory activities against CVB5 and RSV, with the 50% effective concentration (EC50) ranging from 13.06 to 14.27 μmol/L and selectivity index (SI) being 5.38-6.41 μmol/L. However, emodin couldn't directly inactivate the viruses or block their absorption to cells. It acted as a biological synthesis inhibitor against CVB4 and RSV in a concentration- and time-dependent manner, especially during the first 0-4 h post-infection. Moreover, emodin could decrease the mRNA expression of IFN-α but enhance TNF-γ expression significantly compared to the viral controls in vitro. Our results provide a molecular basis for development of emodin as a novel and safe antiviral agent for human enterovirus and respiratory virus infection in the clinical therapy.

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.

HAUS8 regulates RLR‑VISA antiviral signaling positively by targeting VISA.

PubMed

He, Tian-Sheng; Chen, Tian; Wang, Dan-Dan; Xu, Liang-Guo

2018-06-15

Mitochondrial anti‑viral signaling protein (VISA), additionally termed MAVS, IPS‑1 and Cardif, is located at the outer membrane of mitochondria and is an essential adaptor in the Rig‑like receptor (RLRs) signaling pathway. Upon viral infection, activated RLRs interact with VISA on mitochondria, forming a RLR‑VISA platform, leading to the recruitment of different TRAF family members, including TRAF3, TRAF2 and TRAF6. This results in the phosphorylation and nuclear translocation of interferon regulatory factors 3 and 7 (IRF3/IRF7) by TANK binding kinase 1 (TBK1) and/or IKKε, as well as activation of NF‑κB, to induce type I interferons (IFNs) and pro‑inflammatory cytokines. It remains to be elucidated how VISA functions as a scaffold for protein complex assembly in mitochondria to regulate RLR‑VISA antiviral signaling. In the present study, it was demonstrated that HAUS augmin like complex subunit 8 (HAUS8) augments the RLR‑VISA‑dependent antiviral signaling pathway by targeting the VISA complex. Co‑immunoprecipitation verified that HAUS8 was associated with VISA and the VISA signaling complex components retinoic acid‑inducible gene I (RIG‑I) and TBK1 when the RLR‑VISA signaling pathway was activated. The data demonstrated that overexpression of HAUS8 significantly promoted the activity of the transcription factors NF‑κB, IRF3 and the IFN‑β promoter induced by Sendai virus‑mediated RLR‑VISA signaling. HAUS8 increased the polyubiquitination of VISA, RIG‑I and TBK1. Knockdown of HAUS8 inhibited the activation of the transcription factors IRF‑3, NF‑κB and the IFN‑β promoter triggered by Sendai virus. Collectively, these results demonstrated that HAUS8 may function as a positive regulator of RLR‑VISA dependent antiviral signaling by targeting the VISA complex, providing a novel regulatory mechanism of antiviral responses.

Regulated production and anti-HIV type 1 activities of cytidine deaminases APOBEC3B, 3F, and 3G.

PubMed

Rose, Kristine M; Marin, Mariana; Kozak, Susan L; Kabat, David

2005-07-01

APOBEC3G and 3F (A3G and A3F) cytidine deaminases incorporate into retroviral cores where they lethally hypermutate nascent DNA reverse transcripts. As substantiated here, the viral infectivity factor (Vif) encoded by human immunodeficiency virus type-1 (HIV-1) binds A3G and A3F and induces their degradation, thereby precluding their incorporation into viral progeny. Previous evidence suggested that A3G is expressed in H9 and other nonpermissive cells that contain this antiviral defense but not in several permissive cells, and that overexpression of A3G or A3F makes permissive cells nonpermissive. Using a broader panel of cell lines, we confirmed a correlation between A3G and cellular abilities to inactivate HIV-1(Deltavif). However, there was a quantitative discrepancy because several cells with weak antiviral activities had similar amounts of wild-type A3G mRNA and protein compared to H9 cells. Antiviral activity of H9 cells was also attenuated in some conditions. These quantitative discrepancies could not be explained by the presence of A3F or other A3G paralogs in some of the cell lines. Thus, A3A, A3B, and A3C had weak but significant anti-HIV-1 activities and did not dominantly interfere with A3G or A3F antiviral functions. Control of A3G synthesis by the protein kinase C/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway was also similar in permissive and nonpermissive cells. A3G in highly permissive cells is degraded by Vif, suggesting that it is not in a sequestered site, and is specifically incorporated in low amounts into HIV-1(Deltavif). Although A3G and/or A3F inactivate HIV-1(Deltavif) and are neutralized by Vif, the antiviral properties of cell lines are also influenced by other cellular and viral factors.

Results of space experiment program "Interferon". II. Influence of spaceflight conditions on the activity of interferon preparations and interferon inducers ("Interferon II").

PubMed

Tálas, M; Bátkai, L; Stöger, I; Nagy, K; Hiros, L; Konstantinova, I; Kozharinov, V

1983-01-01

The influence of spaceflight conditions on the biological activity of HuIFN-alpha preparations (lyophilized, in solution and in ointment) and interferon inducers was studied. In antiviral activity no difference was observed between the samples kept aboard the spaceship and the controls kept under ground conditions. The interferon inducers poly I:C, poly G:C and gossipol placed in the space laboratory for 7 days maintained their interferon-inducing capacity. The circulating interferon level in mice was the same irrespective of the induction being performed with flight or ground-control samples of inducers.

Comparison of Antiviral Activity between IgA and IgG Specific to Influenza Virus Hemagglutinin: Increased Potential of IgA for Heterosubtypic Immunity

PubMed Central

Yokoyama, Ayaka; Miyamoto, Hiroko; Kajihara, Masahiro; Maruyama, Junki; Nao, Naganori; Manzoor, Rashid; Takada, Ayato

2014-01-01

Both IgA and IgG antibodies are known to play important roles in protection against influenza virus infection. While IgG is the major isotype induced systemically, IgA is predominant in mucosal tissues, including the upper respiratory tract. Although IgA antibodies are believed to have unique advantages in mucosal immunity, information on direct comparisons of the in vitro antiviral activities of IgA and IgG antibodies recognizing the same epitope is limited. In this study, we demonstrate differences in antiviral activities between these isotypes using monoclonal IgA and IgG antibodies obtained from hybridomas of the same origin. Polymeric IgA-producing hybridoma cells were successfully subcloned from those originally producing monoclonal antibody S139/1, a hemaggulutinin (HA)-specific IgG that was generated against an influenza A virus strain of the H3 subtype but had cross-neutralizing activities against the H1, H2, H13, and H16 subtypes. These monoclonal S139/1 IgA and IgG antibodies were assumed to recognize the same epitope and thus used to compare their antiviral activities. We found that both S139/1 IgA and IgG antibodies strongly bound to the homologous H3 virus in an enzyme-linked immunosorbent assay, and there were no significant differences in their hemagglutination-inhibiting and neutralizing activities against the H3 virus. In contrast, S139/1 IgA showed remarkably higher cross-binding to and antiviral activities against H1, H2, and H13 viruses than S139/1 IgG. It was also noted that S139/1 IgA, but not IgG, drastically suppressed the extracellular release of the viruses from infected cells. Electron microscopy revealed that S139/1 IgA deposited newly produced viral particles on the cell surface, most likely by tethering the particles. These results suggest that anti-HA IgA has greater potential to prevent influenza A virus infection than IgG antibodies, likely due to increased avidity conferred by its multivalency, and that this advantage may be particularly important for heterosubtypic immunity. PMID:24465606

[Quantitative real-time PCR--usefulness in detection and monitoring of CMV infection after hematopeietic stem cells transplant].

PubMed

Grabarczyk, Piotr; Brojer, Ewa; Nasiłowska, Barbara; Mariańska, Bozena

2006-09-01

It is recommended that all patients after allogeneic hematopoietic stem cell transplantation (alloHSCT) should be monitored for CMV infection markers. The aim of the study was to check the usefulness of quantitative DNA CMV monitoring after alloHSCT. DNA CMV was tested by real-time PCR in sera and blood samples twice a week until 30th day after alloHSCT thereafter, once a week until 100th day and then, once every 2-3 weeks. 832 samples from 16 patients were tested. All patients were anti-CMV positive or/and received stem cells from seropositive donors. Introduction of antiviral treatment was based on initial viral load and its rate of increase. DNA CMV was detected in 13/16 patients; in 3 before 30h day after allo HSCT (group I) and in 10 (group II) after 30th day. In all patients from group I clinical symptoms were observed and DNA CMV was detected in sera and blood samples. Peak viral load was 2490-34 620 geq/ml. Although antiviral treatment was applied, reinfection was observed and infection lasted from 28 to 91 days. In 6 group II patients, clinical symptoms were observed and DNA CMV in sera and blood was detected for 16-56 days, DNA CMV peak load was 100-8950 geq/ml. In the remaining 4 patients, no clinical symptoms were observed--DNA CMV was detected in blood only for 7 to 14 days. In one patient with peak viral load 10,540 geq/ml, antiviral treatment was applied. In 3 with viral load of 400-2000 geq/ml, treatment was not introduced. The quantitative DNA CMV results were taken into account before the change of antiviral drugs for more effective drugs and the decrease of drug dose due to side effects. Application of quantititative DNA CMV testing allowed to optimise antiviral drug administration in immunosupressed patients after alloHSCT

Update on HIV resistance and resistance testing.

PubMed

Sebastian, Joseph; Faruki, Hawazin

2004-01-01

The introduction of highly active antiretroviral therapy, including a combination of antivirals directed at various steps in the viral life cycle, has led to significant decreases in morbidity and mortality associated with human immunodeficiency virus (HIV-1) infections. Despite the availability of numerous antivirals, many extensively treated patients gradually loose the ability to control viral replication because of development of antiviral resistance. Laboratory tests have been developed and validated to assist in recognizing such resistance and to help predict which antivirals may be more likely to control viral replication in a given patient. Both genotypic and phenotypic assays have been developed to assess HIV-1 antiviral resistance. The assay methodologies, including the advantages and disadvantages of each method, as well as the limitations of each method are reviewed. The ability to predict likely drug response from a genotype or a phenotype is continually evolving, and the more recently discovered mutation/drug resistance associations are discussed in terms of their implications for HIV resistance assays. To provide additional options for those who have developed resistance to all currently available drugs, new antivirals, such as the fusion inhibitors, are being developed. These new classes of antivirals block the HIV viral life cycle at sites other than reverse transcriptase and protease. Unique and novel resistance assays are being developed to measure HIV resistance to these new drugs. Copyright 2003 Wiley Periodicals, Inc.

Arbidol: a quarter-century after. Past, present and future of the original Russian antiviral

NASA Astrophysics Data System (ADS)

Balakin, K. V.; Filosa, R.; Lavrenov, S. N.; Mkrtchayn, A. S.; Nawrozkij, M. B.; Novakov, I. A.

2018-06-01

The present review is concerned with the synthesis and structure–activity relationship studies of Arbidol and its structural analogues. The latter are roughly divided into several unequal parts: indole- and benzofuran-based compounds, benzimidazole and imidazopyridine bioisosteres and ring-expanded quinoline derivatives. Much attention is focused on various types of antiviral activity of the above-mentioned Arbidol congeners, as well as of the parent compound itself. Features of Arbidol synthesis and metabolic changes are also discussed. The bibliography includes 166 references.

An antivirally active sulfated polysaccharide from Sargassum horneri (TURNER) C. AGARDH.

PubMed

Hoshino, T; Hayashi, T; Hayashi, K; Hamada, J; Lee, J B; Sankawa, U

1998-07-01

A sulfated polysaccharide was isolated from the hot water extract of a brown alga, Sargassum horneri (TURNER) C. AGARDH. Fucose was detected as the main component sugar of this polysaccharide. This compound showed potent antiviral activity against herpes simplex virus type 1, human cytomegalovirus and human immunodeficiency virus type 1. Time-of-addition experiments suggested that it inhibited not only the initial stages of viral infection, such as attachment to and penetration into host cells, but also later replication stages after virus penetration.

The C-Terminal Tail of TRIM56 Dictates Antiviral Restriction of Influenza A and B Viruses by Impeding Viral RNA Synthesis

PubMed Central

Liu, Baoming; Li, Nan L.; Shen, Yang; Bao, Xiaoyong; Elbahesh, Husni; Webby, Richard J.

2016-01-01

ABSTRACT Accumulating data suggest that tripartite-motif-containing (TRIM) proteins participate in host responses to viral infections, either by acting as direct antiviral restriction factors or through regulating innate immune signaling of the host. Of >70 TRIMs, TRIM56 is a restriction factor of several positive-strand RNA viruses, including three members of the family Flaviviridae (yellow fever virus, dengue virus, and bovine viral diarrhea virus) and a human coronavirus (OC43), and this ability invariably depends upon the E3 ligase activity of TRIM56. However, the impact of TRIM56 on negative-strand RNA viruses remains unclear. Here, we show that TRIM56 puts a check on replication of influenza A and B viruses in cell culture but does not inhibit Sendai virus or human metapneumovirus, two paramyxoviruses. Interestingly, the anti-influenza virus activity was independent of the E3 ligase activity, B-box, or coiled-coil domain. Rather, deletion of a 63-residue-long C-terminal-tail portion of TRIM56 abrogated the antiviral function. Moreover, expression of this short C-terminal segment curtailed the replication of influenza viruses as effectively as that of full-length TRIM56. Mechanistically, TRIM56 was found to specifically impede intracellular influenza virus RNA synthesis. Together, these data reveal a novel antiviral activity of TRIM56 against influenza A and B viruses and provide insights into the mechanism by which TRIM56 restricts these medically important orthomyxoviruses. IMPORTANCE Options to treat influenza are limited, and drug-resistant influenza virus strains can emerge through minor genetic changes. Understanding novel virus-host interactions that alter influenza virus fitness may reveal new targets/approaches for therapeutic interventions. We show here that TRIM56, a tripartite-motif protein, is an intrinsic host restriction factor of influenza A and B viruses. Unlike its antiviral actions against positive-strand RNA viruses, the anti-influenza virus activity of TRIM56 was independent of the E3 ligase activity. Rather, expression of a short segment within the very C-terminal tail of TRIM56 inhibited the replication of influenza viruses as effectively as that of full-length TRIM56 by specifically targeting viral RNA synthesis. These data reveal the remarkable multifaceted activity of TRIM56, which has developed multiple domains to inhibit multiple viral families. They also raise the possibility of developing a broad-spectrum, TRIM56-based antiviral approach for addition to influenza prophylaxis and/or control strategies. PMID:26889027

Conceptual framework for outcomes research studies of hepatitis C: an analytical review

PubMed Central

Sbarigia, Urbano; Denee, Tom R; Turner, Norris G; Wan, George J; Morrison, Alan; Kaufman, Anna S; Rice, Gary; Dusheiko, Geoffrey M

2016-01-01

Hepatitis C virus infection is one of the main causes of chronic liver disease worldwide. Until recently, the standard antiviral regimen for hepatitis C was a combination of an interferon derivative and ribavirin, but a plethora of new antiviral drugs is becoming available. While these new drugs have shown great efficacy in clinical trials, observational studies are needed to determine their effectiveness in clinical practice. Previous observational studies have shown that multiple factors, besides the drug regimen, affect patient outcomes in clinical practice. Here, we provide an analytical review of published outcomes studies of the management of hepatitis C virus infection. A conceptual framework defines the relationships between four categories of variables: health care system structure, patient characteristics, process-of-care, and patient outcomes. This framework can provide a starting point for outcomes studies addressing the use and effectiveness of new antiviral drug treatments. PMID:27313473

Structure-Activity Relationships of Acyclic Selenopurine Nucleosides as Antiviral Agents.

PubMed

Sahu, Pramod K; Umme, Tamima; Yu, Jinha; Kim, Gyudong; Qu, Shuhao; Naik, Siddhi D; Jeong, Lak Shin

2017-07-12

A series of acyclic selenopurine nucleosides 3a - f and 4a - g were synthesized based on the bioisosteric rationale between oxygen and selenium, and then evaluated for antiviral activity. Among the compounds tested, seleno-acyclovir ( 4a ) exhibited the most potent anti-herpes simplex virus (HSV)-1 (EC 50 = 1.47 µM) and HSV-2 (EC 50 = 6.34 µM) activities without cytotoxicity up to 100 µM, while 2,6-diaminopurine derivatives 4e - g exhibited significant anti-human cytomegalovirus (HCMV) activity, which is slightly more potent than the guanine derivative 4d , indicating that they might act as prodrugs of seleno-ganciclovir ( 4d ).

A unifying view of the broad-spectrum antiviral activity of RSAD2 (viperin) based on its radical-SAM chemistry.

PubMed

Honarmand Ebrahimi, Kourosh

2018-04-25

RSAD2 (cig-5), also known as viperin (virus inhibitory protein, endoplasmic reticulum associated, interferon inducible), is a member of the radical S-adenosylmethionine (SAM) superfamily of enzymes. Since the discovery of this enzyme more than a decade ago, numerous studies have shown that it exhibits antiviral activity against a wide range of viruses. However, there is no clear picture demonstrating the mechanism by which RSAD2 restricts the replication process of different viruses, largely because there is no direct evidence describing its in vivo enzymatic activity. As a result, a multifunctionality model has emerged. According to this model the mechanism by which RSAD2 restricts replication of different viruses varies and in many cases is not dependent on the radical-SAM chemistry of RSAD2. If the radical-SAM activity of RSAD2 is not required for its antiviral function, the question worth asking is: why does the cellular defence mechanism induce the expression of the radical-SAM enzyme RSAD2, which is metabolically expensive due to the requirement for a [4Fe-4S] cluster and usage of SAM? Here, in contrast to the multifunctionality view, I put forward a unifying model. I postulate that the radical-SAM activity of RSAD2 modulates cellular metabolic pathways essential for viral replication and/or cell proliferation and survival. As a result, its catalytic activity restricts the replication of a wide range of viruses via a common cellular function. This view is based on recent discoveries hinting towards possible substrates of RSAD2, re-evaluation of previous studies regarding the antiviral activity of RSAD2, and accumulating evidence suggesting a role of human RSAD2 in the metabolic reprogramming of cells.

Entecavir Exhibits Inhibitory Activity against Human Immunodeficiency Virus under Conditions of Reduced Viral Challenge▿

PubMed Central

Lin, Pin-Fang; Nowicka-Sans, Beata; Terry, Brian; Zhang, Sharon; Wang, Chunfu; Fan, Li; Dicker, Ira; Gali, Volodymyr; Higley, Helen; Parkin, Neil; Tenney, Daniel; Krystal, Mark; Colonno, Richard

2008-01-01

Entecavir (ETV) was developed for the treatment of chronic hepatitis B virus (HBV) infection and is globally approved for that indication. Initial preclinical studies indicated that ETV had no significant activity against human immunodeficiency virus type 1 (HIV-1) in cultured cell lines at physiologically relevant ETV concentrations, using traditional anti-HIV assays. In response to recent clinical observations of anti-HIV activity of ETV in HIV/HBV-coinfected patients not receiving highly active antiretroviral therapy (HAART), additional investigative studies were conducted to expand upon earlier results. An extended panel of HIV-1 laboratory and clinical strains and cell types was tested against ETV, along with a comparison of assay methodologies and resistance profiling. These latest studies confirmed that ETV has only weak activity against HIV, using established assay systems. However, a >100-fold enhancement of antiviral activity (equivalent to the antiviral activity of lamivudine) could be obtained when assay conditions were modified to reduce the initial viral challenge. Also, the selection of a M184I virus variant during the passage of HIV-1 at high concentrations of ETV confirmed that ETV can exert inhibitory pressure on the virus. These findings may have a significant impact on how future assays are performed with compounds to be used in patients infected with HIV. These results support the recommendation that ETV therapy should be administered in concert with HAART for HIV/HBV-coinfected patients. PMID:18316521

Viral-specific T-cell transfer from HSCT donor for the treatment of viral infections or diseases after HSCT.

PubMed

Qian, C; Wang, Y; Reppel, L; D'aveni, M; Campidelli, A; Decot, V; Bensoussan, D

2018-02-01

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative option for treatment of some malignant and non-malignant hematological diseases. However, post-HSCT patients are severely immunocompromised and susceptible to viral infections, which are a major cause of morbidity and mortality. Although antiviral agents are now available for most types of viral infections, they are not devoid of side effects and their efficacy is limited when there is no concomitant antiviral immune reconstitution. In recent decades, adoptive transfer of viral-specific T cells (VSTs) became an alternative treatment for viral infection after HSCT. However, two major issues are concerned in VST transfer: the risk of GVHD and antiviral efficacy. We report an exhaustive review of the published studies that focus on prophylactic and/or curative therapy by donor VST transfer for post-HSCT common viral infections. A low incidence of GVHD and a good antiviral efficacy was observed after adoptive transfer of VSTs from HSCT donor. Viral-specific T-cell transfer is a promising approach for a broad clinical application. Nevertheless, a randomized controlled study in a large cohort of patients comparing antiviral treatment alone to antiviral treatment combined with VSTs is still needed to demonstrate efficacy and safety.

Pokeweed Antiviral Protein, a Ribosome Inactivating Protein: Activity, Inhibition and Prospects

PubMed Central

Domashevskiy, Artem V.; Goss, Dixie J.

2015-01-01

Viruses employ an array of elaborate strategies to overcome plant defense mechanisms and must adapt to the requirements of the host translational systems. Pokeweed antiviral protein (PAP) from Phytolacca americana is a ribosome inactivating protein (RIP) and is an RNA N-glycosidase that removes specific purine residues from the sarcin/ricin (S/R) loop of large rRNA, arresting protein synthesis at the translocation step. PAP is thought to play an important role in the plant’s defense mechanism against foreign pathogens. This review focuses on the structure, function, and the relationship of PAP to other RIPs, discusses molecular aspects of PAP antiviral activity, the novel inhibition of this plant toxin by a virus counteraction—a peptide linked to the viral genome (VPg), and possible applications of RIP-conjugated immunotoxins in cancer therapeutics. PMID:25635465

Emerging Role of Ubiquitination in Antiviral RIG-I Signaling

PubMed Central

Maelfait, Jonathan

2012-01-01

Summary: Detection of viruses by the innate immune system involves the action of specialized pattern recognition receptors. Intracellular RIG-I receptors sense the presence of viral nucleic acids in infected cells and trigger signaling pathways that lead to the production of proinflammatory and antiviral proteins. Over the past few years, posttranslational modification of RIG-I and downstream signaling proteins by different types of ubiquitination has been found to be a key event in the regulation of RIG-I-induced NF-κB and interferon regulatory factor 3 (IRF3) activation. Multiple ubiquitin ligases, deubiquitinases, and ubiquitin binding scaffold proteins contribute to both positive and negative regulation of the RIG-I-induced antiviral immune response. A better understanding of the function and activity of these proteins might eventually lead to the development of novel therapeutic approaches for management of viral diseases. PMID:22390971

Group I but not group II NPV induces antiviral effects in mammalian cells.

PubMed

Liang, Changyong; Song, Jianhua; Hu, Zhihong; Chen, Xinwen

2006-10-01

Nucleopolyhedrovirus (NPV) is divided into Group I and Group II based on the phylogenetic analysis. It has been reported that Group I NPVs such as Autographa californica multiple NPV (AcMNPV) can transduce mammalian cells, while Group II NPVs such as Helicoverpa armigera single NPV (HaSNPV) cannot. Here we report that AcMNPV was capable of stimulating antiviral activity in human hepatoma cells (SMMC-7721) manifested by inhibition of Vesicular Stomatitis virus (VSV) replication. In contrast, the HaSNPV and the Spodoptera exigua multiple NPV (SeMNPV) of group II had no inhibitory effect on VSV. Recombinant AcMNPV was shown to induce interferons alpha/beta even in the absence of transgene expression in human SMMC-7721 cells, while it mediated transgene expression in BHK and L929 mammalian cells without an ensuing antiviral activity.

Favipiravir elicits antiviral mutagenesis during virus replication in vivo.

PubMed

Arias, Armando; Thorne, Lucy; Goodfellow, Ian

2014-10-21

Lethal mutagenesis has emerged as a novel potential therapeutic approach to treat viral infections. Several studies have demonstrated that increases in the high mutation rates inherent to RNA viruses lead to viral extinction in cell culture, but evidence during infections in vivo is limited. In this study, we show that the broad-range antiviral nucleoside favipiravir reduces viral load in vivo by exerting antiviral mutagenesis in a mouse model for norovirus infection. Increased mutation frequencies were observed in samples from treated mice and were accompanied with lower or in some cases undetectable levels of infectious virus in faeces and tissues. Viral RNA isolated from treated animals showed reduced infectivity, a feature of populations approaching extinction during antiviral mutagenesis. These results suggest that favipiravir can induce norovirus mutagenesis in vivo, which in some cases leads to virus extinction, providing a proof-of-principle for the use of favipiravir derivatives or mutagenic nucleosides in the clinical treatment of noroviruses.

Antifungal and Antiviral Cyclic Peptides from the Deep-Sea-Derived Fungus Simplicillium obclavatum EIODSF 020.

PubMed

Liang, Xiao; Nong, Xu-Hua; Huang, Zhong-Hui; Qi, Shu-Hua

2017-06-28

A new linear peptide simplicilliumtide I (1) and four new cyclic peptides simplicilliumtides J-M (2-5) together with known analogues verlamelins A and B (6 and 7) were isolated from the deep-sea-derived fungal strain Simplicillium obclavatum EIODSF 020. Their structures were elucidated by spectroscopic analysis, and their absolute configurations were further confirmed by chemical structural modification, Marfey's and Mosher's methods. Compounds 2, 6, and 7 showed significant antifungal activity toward Aspergillus versicolor and Curvularia australiensis and also had obvious antiviral activity toward HSV-1 with IC 50 values of 14.0, 16.7, and 15.6 μM, respectively. The structure-bioactivity relationship of this type of cyclic peptide was also discussed. This is the first time to discuss the effects of the lactone linkage and the substituent group of the fatty acid chain fragment on the bioactivity of this type of cyclic peptides. This is also the first time to report the antiviral activity of these cyclic peptides.

Engineering a therapeutic lectin by uncoupling mitogenicity from antiviral activity.

PubMed

Swanson, Michael D; Boudreaux, Daniel M; Salmon, Loïc; Chugh, Jeetender; Winter, Harry C; Meagher, Jennifer L; André, Sabine; Murphy, Paul V; Oscarson, Stefan; Roy, René; King, Steven; Kaplan, Mark H; Goldstein, Irwin J; Tarbet, E Bart; Hurst, Brett L; Smee, Donald F; de la Fuente, Cynthia; Hoffmann, Hans-Heinrich; Xue, Yi; Rice, Charles M; Schols, Dominique; Garcia, J Victor; Stuckey, Jeanne A; Gabius, Hans-Joachim; Al-Hashimi, Hashim M; Markovitz, David M

2015-10-22

A key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino-acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity, while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity, while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code. Copyright © 2015 Elsevier Inc. All rights reserved.

Engineering a Therapeutic Lectin by Uncoupling Mitogenicity from Antiviral Activity

PubMed Central

Swanson, Michael D.; Boudreaux, Daniel M.; Salmon, Loïc; Chugh, Jeetender; Winter, Harry C.; Meagher, Jennifer L.; André, Sabine; Murphy, Paul V.; Oscarson, Stefan; Roy, René; King, Steven; Kaplan, Mark H.; Goldstein, Irwin J.; Tarbet, E. Bart; Hurst, Brett L.; Smee, Donald F.; de la Fuente, Cynthia; Hoffmann, Hans-Heinrich; Xue, Yi; Rice, Charles M.; Schols, Dominique; Garcia, J. Victor; Stuckey, Jeanne A.; Gabius, Hans-Joachim; Al-Hashimi, Hashim M.; Markovitz, David M.

2015-01-01

Summary A key effector route of the Sugar Code involves lectins that exert crucial regulatory controls by targeting distinct cellular glycans. We demonstrate that a single amino acid substitution in a banana lectin, replacing histidine 84 with a threonine, significantly reduces its mitogenicity while preserving its broad-spectrum antiviral potency. X-ray crystallography, NMR spectroscopy, and glycocluster assays reveal that loss of mitogenicity is strongly correlated with loss of pi-pi stacking between aromatic amino acids H84 and Y83, which removes a wall separating two carbohydrate binding sites, thus diminishing multivalent interactions. On the other hand, monovalent interactions and antiviral activity are preserved by retaining other wild-type conformational features and possibly through unique contacts involving the T84 side chain. Through such fine-tuning, target selection and downstream effects of a lectin can be modulated so as to knock down one activity while preserving another, thus providing tools for therapeutics and for understanding the Sugar Code. PMID:26496612

OAS proteins and cGAS: unifying concepts in sensing and responding to cytosolic nucleic acids.

PubMed

Hornung, Veit; Hartmann, Rune; Ablasser, Andrea; Hopfner, Karl-Peter

2014-08-01

Recent discoveries in the field of innate immunity have highlighted the existence of a family of nucleic acid-sensing proteins that have similar structural and functional properties. These include the well-known oligoadenylate synthase (OAS) family proteins and the recently identified OAS homologue cyclic GMP-AMP (cGAMP) synthase (cGAS). The OAS proteins and cGAS are template-independent nucleotidyltransferases that, once activated by double-stranded nucleic acids in the cytosol, produce unique classes of 2'-5'-linked second messenger molecules, which - through distinct mechanisms - have crucial antiviral functions. 2'-5'-linked oligoadenylates limit viral propagation through the activation of the enzyme RNase L, which degrades host and viral RNA, and 2'-5'-linked cGAMP activates downstream signalling pathways to induce de novo antiviral gene expression. In this Progress article, we describe the striking functional and structural similarities between OAS proteins and cGAS, and highlight their roles in antiviral immunity.

Crotoxin and phospholipases A₂ from Crotalus durissus terrificus showed antiviral activity against dengue and yellow fever viruses.

PubMed

Muller, Vanessa Danielle Menjon; Russo, Raquel Rinaldi; Cintra, Adelia Cristina Oliveira; Sartim, Marco Aurélio; Alves-Paiva, Raquel De Melo; Figueiredo, Luiz Tadeu Moraes; Sampaio, Suely Vilela; Aquino, Victor Hugo

2012-03-15

Dengue is the most important arbovirus in the world with an estimated of 50 million dengue infections occurring annually and approximately 2.5 billion people living in dengue endemic countries. Yellow fever is a viral hemorrhagic fever with high mortality that is transmitted by mosquitoes. Effective vaccines against yellow fever have been available for almost 70 years and are responsible for a significant reduction of occurrences of the disease worldwide; however, approximately 200,000 cases of yellow fever still occur annually, principally in Africa. Therefore, it is a public health priority to develop antiviral agents for treatment of these virus infections. Crotalus durissus terrificus snake, a South American rattlesnake, presents venom with several biologically actives molecules. In this study, we evaluated the antiviral activity of crude venom and isolated toxins from Crotalus durissus terrificus and found that phospholipases A₂ showed a high inhibition of Yellow fever and dengue viruses in VERO E6 cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dynamic expression profiling of type I and type III interferon-stimulated hepatocytes reveals a stable hierarchy of gene expression.

PubMed

Bolen, Christopher R; Ding, Siyuan; Robek, Michael D; Kleinstein, Steven H

2014-04-01

Despite activating similar signaling cascades, the type I and type III interferons (IFNs) differ in their ability to antagonize virus replication. However, it is not clear whether these cytokines induce unique antiviral states, particularly in the liver, where the clinically important hepatitis B and C viruses cause persistent infection. Here, clustering and promoter analyses of microarray-based gene expression profiling were combined with mechanistic studies of signaling pathways to dynamically characterize the transcriptional responses induced by these cytokines in Huh7 hepatoma cells and primary human hepatocytes. Type I and III IFNs differed greatly in their level of interferon-stimulated gene (ISG) induction with a clearly detectable hierarchy (IFN-β > IFN-α > IFN-λ3 > IFN-λ1 > IFN-λ2). Notably, although the hierarchy identified varying numbers of differentially expressed genes when quantified using common statistical thresholds, further analysis of gene expression over multiple timepoints indicated that the individual IFNs do not in fact regulate unique sets of genes. The kinetic profiles of IFN-induced gene expression were also qualitatively similar with the important exception of IFN-α. While stimulation with either IFN-β or IFN-λs resulted in a similar long-lasting ISG induction, IFN-α signaling peaked early after stimulation then declined due to a negative feedback mechanism. The quantitative expression hierarchy and unique kinetics of IFN-α reveal potential specific roles for individual IFNs in the immune response, and elucidate the mechanism behind previously observed differences in IFN antiviral activity. While current clinical trials are focused on IFN-λ1 as a potential antiviral therapy, the finding that IFN-λ3 invariably possesses the highest activity among type III IFNs suggests that this cytokine may have superior clinical activity. © 2014 by the American Association for the Study of Liver Diseases.

Activation of cGAS-dependent antiviral responses by DNA intercalating agents.

PubMed

Pépin, Geneviève; Nejad, Charlotte; Thomas, Belinda J; Ferrand, Jonathan; McArthur, Kate; Bardin, Philip G; Williams, Bryan R G; Gantier, Michael P

2017-01-09

Acridine dyes, including proflavine and acriflavine, were commonly used as antiseptics before the advent of penicillins in the mid-1940s. While their mode of action on pathogens was originally attributed to their DNA intercalating activity, work in the early 1970s suggested involvement of the host immune responses, characterized by induction of interferon (IFN)-like activities through an unknown mechanism. We demonstrate here that sub-toxic concentrations of a mixture of acriflavine and proflavine instigate a cyclic-GMP-AMP (cGAMP) synthase (cGAS)-dependent type-I IFN antiviral response. This pertains to the capacity of these compounds to induce low level DNA damage and cytoplasmic DNA leakage, resulting in cGAS-dependent cGAMP-like activity. Critically, acriflavine:proflavine pre-treatment of human primary bronchial epithelial cells significantly reduced rhinovirus infection. Collectively, our findings constitute the first evidence that non-toxic DNA binding agents have the capacity to act as indirect agonists of cGAS, to exert potent antiviral effects in mammalian cells. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes

PubMed Central

Kubiça, Thaís F.; Alves, Sydney H.; Weiblen, Rudi; Lovato, Luciane T.

2014-01-01

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 μg mL−1) and 1,8-cineole (CC50 = 2996.10 μg mL−1) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle. PMID:24948933

Downregulation of Cellular c-Jun N-Terminal Protein Kinase and NF-κB Activation by Berberine May Result in Inhibition of Herpes Simplex Virus Replication

PubMed Central

Song, Siwei; Qiu, Min; Chu, Ying; Chen, Deyan; Wang, Xiaohui; Su, Airong

2014-01-01

Berberine is a quaternary ammonium salt from the protoberberine group of isoquinoline alkaloids. Some reports show that berberine exhibits anti-inflammatory, antitumor, and antiviral properties by modulating multiple cellular signaling pathways, including p53, nuclear factor κB (NF-κB), and mitogen-activated protein kinase. In the present study, we investigated the antiviral effect of berberine against herpes simplex virus (HSV) infection. Current antiherpes medicines such as acyclovir can lessen the recurring activation when used early at infection but are unable to prevent or cure infections where treatment has selected for resistant mutants. In searching for new antiviral agents against herpesvirus infection, we found that berberine reduced viral RNA transcription, protein synthesis, and virus titers in a dose-dependent manner. To elucidate the mechanism of its antiviral activity, the effect of berberine on the individual steps of viral replication cycle of HSV was investigated via time-of-drug addition assay. We found that berberine acted at the early stage of HSV replication cycle, between viral attachment/entry and genomic DNA replication, probably at the immediate-early gene expression stage. We further demonstrated that berberine significantly reduced HSV-induced NF-κB activation, as well as IκB-α degradation and p65 nuclear translocation. Moreover, we found that berberine also depressed HSV-induced c-Jun N-terminal kinase (JNK) phosphorylation but had little effect on p38 phosphorylation. Our results suggest that the berberine inhibition of HSV infection may be mediated through modulating cellular JNK and NF-κB pathways. PMID:24913175

The Amphibian Antimicrobial Peptide Temporin B Inhibits In Vitro Herpes Simplex Virus 1 Infection.

PubMed

Marcocci, M E; Amatore, D; Villa, S; Casciaro, B; Aimola, P; Franci, G; Grieco, P; Galdiero, M; Palamara, A T; Mangoni, M L; Nencioni, L

2018-05-01

The herpes simplex virus 1 (HSV-1) is widespread in the population, and in most cases its infection is asymptomatic. The currently available anti-HSV-1 drugs are acyclovir and its derivatives, although long-term therapy with these agents can lead to drug resistance. Thus, the discovery of novel antiherpetic compounds deserves additional effort. Naturally occurring antimicrobial peptides (AMPs) represent an interesting class of molecules with potential antiviral properties. To the best of our knowledge, this study is the first demonstration of the in vitro anti-HSV-1 activity of temporin B (TB), a short membrane-active amphibian AMP. In particular, when HSV-1 was preincubated with 20 μg/ml TB, significant antiviral activity was observed (a 5-log reduction of the virus titer). Such an effect was due to the disruption of the viral envelope, as demonstrated by transmission electron microscopy. Moreover, TB partially affected different stages of the HSV-1 life cycle, including the attachment and the entry of the virus into the host cell, as well as the subsequent postinfection phase. Furthermore, its efficacy was confirmed on human epithelial cells, suggesting TB as a novel approach for the prevention and/or treatment of HSV-1 infections. Copyright © 2018 Marcocci et al.

Evaluation of green tea extract as a safe personal hygiene against viral infections.

PubMed

Lee, Yun Ha; Jang, Yo Han; Kim, Young-Seok; Kim, Jinku; Seong, Baik Lin

2018-01-01

Viral infections often pose tremendous public health concerns as well as economic burdens. Despite the availability of vaccines or antiviral drugs, personal hygiene is considered as effective means as the first-hand measure against viral infections. The green tea catechins, in particular, epigallocatechin-3-gallate (EGCG), are known to exert potent antiviral activity. In this study, we evaluated the green tea extract as a safe personal hygiene against viral infections. Using the influenza virus A/Puerto Rico/8/34 (H1N1) as a model, we examined the duration of the viral inactivating activity of green tea extract (GTE) under prolonged storage at various temperature conditions. Even after the storage for 56 days at different temperatures, 0.1% GTE completely inactivated 10 6 PFU of the virus (6 log 10 reduction), and 0.01% and 0.05% GTE resulted in 2 log 10 reduction of the viral titers. When supplemented with 2% citric acid, 0.1% sodium benzoate, and 0.2% ascorbic acid as anti-oxidant, the inactivating activity of GTE was temporarily compromised during earlier times of storage. However, the antiviral activity of the GTE was steadily recovered up to similar levels with those of the same concentrations of GTE without the supplements, effectively prolonging the duration of the virucidal function over extended period. Cryo-EM and DLS analyses showed a slight increase in the overall size of virus particles by GTE treatment. The results suggest that the virucidal activity of GTE is mediated by oxidative crosslinking of catechins to the viral proteins and the change of physical properties of viral membranes. The durability of antiviral effects of GTE was examined as solution type and powder types over extended periods at various temperature conditions using human influenza A/H1N1 virus. GTE with supplements demonstrated potent viral inactivating activity, resulting in greater than 4 log 10 reduction of viral titers even after storage for up to two months at a wide range of temperatures. These data suggest that GTE-based antiviral agents could be formulated as a safe and environmentally friendly personal hygiene against viral infections.

Cross-species antiviral activity of goose interferon lambda against duck plague virus is related to its positive self-regulatory feedback loop.

PubMed

Chen, Shun; Zhang, Wei; Zhou, Qin; Wang, Anqi; Sun, Lipei; Wang, Mingshu; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Sun, Kunfeng; Yang, Qiao; Wu, Ying; Chen, Xiaoyue; Cheng, Anchun

2017-06-01

Duck plague virus (DPV) is a virus of the Herpesviridae family that leads to acute disease with a high mortality rate in ducks. Control of the disease contributes to the development of poultry breeding. Type III IFN family (IFN-λs) is a novel member of the IFN family, and goose IFN-λ (goIFN-λ) is a newly identified gene whose antiviral function has only been investigated to a limited extent. Here, the cross-species antiviral activity of goIFN-λ against DPV in duck embryo fibroblasts (DEFs) was studied. We found that pre-treatment with goIFN-λ greatly increased the expression of IFN-λ in both heterologous DEFs and homologous goose embryo fibroblasts (GEFs), while differentially inducing IFNα- and IFN-stimulated genes. Additionally, a positive self-regulatory feedback loop of goIFN-λ was blocked by a mouse anti-goIFN-λ polyclonal antibody, which was confirmed in both homologous GEFs and goose peripheral blood mononuclear cells (PBMCs). The suppression of the BAC-DPV-EGFP by goIFN-λ in DEFs was confirmed by fluorescence microscopy, flow cytometry (FCM) analysis, viral copies and titre detection, which can be rescued by mouse anti-goIFN-λ polyclonal antibody incubation. Finally, reporter gene assays indicated that the cross-species antiviral activity of goIFN-λ against BAC-DPV-EGFP is related to its positive self-regulatory feedback loop and subsequent ISG induction. Our data shed light on the fundamental mechanisms of goIFN-λ antiviral function in vitro and extend the considerable range of therapeutic applications in multiple-poultry disease.

Antiviral effects of artesunate on polyomavirus BK replication in primary human kidney cells.

PubMed

Sharma, Biswa Nath; Marschall, Manfred; Henriksen, Stian; Rinaldo, Christine Hanssen

2014-01-01

Polyomavirus BK (BKV) causes polyomavirus-associated nephropathy (PyVAN) and hemorrhagic cystitis (PyVHC) in renal and bone marrow transplant patients, respectively. Antiviral drugs with targeted activity against BKV are lacking. Since the antimalarial drug artesunate was recently demonstrated to have antiviral activity, the possible effects of artesunate on BKV replication in human primary renal proximal tubular epithelial cells (RPTECs), the host cells in PyVAN, were explored. At 2 h postinfection (hpi), RPTECs were treated with artesunate at concentrations ranging from 0.3 to 80 μM. After one viral replication cycle (approximately 72 hpi), the loads of extracellular BKV DNA, reflecting viral progeny production, were reduced in a concentration-dependent manner. Artesunate at 10 μM reduced the extracellular BKV load by 65%; early large T antigen mRNA and protein expression by 30% and 75%, respectively; DNA replication by 73%; and late VP1 mRNA and protein expression by 47% and 64%, respectively. Importantly, the proliferation of RPTECs was also inhibited in a concentration-dependent manner. At 72 hpi, artesunate at 10 μM reduced cellular DNA replication by 68% and total metabolic activity by 47%. Cell impedance and lactate dehydrogenase measurements indicated a cytostatic but not a cytotoxic mechanism. Flow cytometry and 5-ethynyl-2'-deoxyuridine incorporation revealed a decreased number of cells in S phase and suggested cell cycle arrest in G0 or G2 phase. Both the antiproliferative and antiviral effects of artesunate at 10 μM were reversible. Thus, artesunate inhibits BKV replication in RPTECs in a concentration-dependent manner by inhibiting BKV gene expression and genome replication. The antiviral mechanism appears to be closely connected to cytostatic effects on the host cell, underscoring the dependence of BKV on host cell proliferative functions.

Antiviral Effects of Artesunate on Polyomavirus BK Replication in Primary Human Kidney Cells

PubMed Central

Sharma, Biswa Nath; Marschall, Manfred; Henriksen, Stian

2014-01-01

Polyomavirus BK (BKV) causes polyomavirus-associated nephropathy (PyVAN) and hemorrhagic cystitis (PyVHC) in renal and bone marrow transplant patients, respectively. Antiviral drugs with targeted activity against BKV are lacking. Since the antimalarial drug artesunate was recently demonstrated to have antiviral activity, the possible effects of artesunate on BKV replication in human primary renal proximal tubular epithelial cells (RPTECs), the host cells in PyVAN, were explored. At 2 h postinfection (hpi), RPTECs were treated with artesunate at concentrations ranging from 0.3 to 80 μM. After one viral replication cycle (approximately 72 hpi), the loads of extracellular BKV DNA, reflecting viral progeny production, were reduced in a concentration-dependent manner. Artesunate at 10 μM reduced the extracellular BKV load by 65%; early large T antigen mRNA and protein expression by 30% and 75%, respectively; DNA replication by 73%; and late VP1 mRNA and protein expression by 47% and 64%, respectively. Importantly, the proliferation of RPTECs was also inhibited in a concentration-dependent manner. At 72 hpi, artesunate at 10 μM reduced cellular DNA replication by 68% and total metabolic activity by 47%. Cell impedance and lactate dehydrogenase measurements indicated a cytostatic but not a cytotoxic mechanism. Flow cytometry and 5-ethynyl-2′-deoxyuridine incorporation revealed a decreased number of cells in S phase and suggested cell cycle arrest in G0 or G2 phase. Both the antiproliferative and antiviral effects of artesunate at 10 μM were reversible. Thus, artesunate inhibits BKV replication in RPTECs in a concentration-dependent manner by inhibiting BKV gene expression and genome replication. The antiviral mechanism appears to be closely connected to cytostatic effects on the host cell, underscoring the dependence of BKV on host cell proliferative functions. PMID:24145549

AVP-IC50 Pred: Multiple machine learning techniques-based prediction of peptide antiviral activity in terms of half maximal inhibitory concentration (IC50).

PubMed

Qureshi, Abid; Tandon, Himani; Kumar, Manoj

2015-11-01

Peptide-based antiviral therapeutics has gradually paved their way into mainstream drug discovery research. Experimental determination of peptides' antiviral activity as expressed by their IC50 values involves a lot of effort. Therefore, we have developed "AVP-IC50 Pred," a regression-based algorithm to predict the antiviral activity in terms of IC50 values (μM). A total of 759 non-redundant peptides from AVPdb and HIPdb were divided into a training/test set having 683 peptides (T(683)) and a validation set with 76 independent peptides (V(76)) for evaluation. We utilized important peptide sequence features like amino-acid compositions, binary profile of N8-C8 residues, physicochemical properties and their hybrids. Four different machine learning techniques (MLTs) namely Support vector machine, Random Forest, Instance-based classifier, and K-Star were employed. During 10-fold cross validation, we achieved maximum Pearson correlation coefficients (PCCs) of 0.66, 0.64, 0.56, 0.55, respectively, for the above MLTs using the best combination of feature sets. All the predictive models also performed well on the independent validation dataset and achieved maximum PCCs of 0.74, 0.68, 0.59, 0.57, respectively, on the best combination of feature sets. The AVP-IC50 Pred web server is anticipated to assist the researchers working on antiviral therapeutics by enabling them to computationally screen many compounds and focus experimental validation on the most promising set of peptides, thus reducing cost and time efforts. The server is available at http://crdd.osdd.net/servers/ic50avp. © 2015 Wiley Periodicals, Inc.

IFN-gamma receptor-deficient mice generate antiviral Th1-characteristic cytokine profiles but altered antibody responses.

PubMed

Schijns, V E; Haagmans, B L; Rijke, E O; Huang, S; Aguet, M; Horzinek, M C

1994-09-01

The lymphokine IFN-gamma is a pleiotropic immunomodulator and possesses intrinsic antiviral activity. We studied its significance in the development of antiviral immune responses by using IFN-gamma receptor-deficient (IFN-gamma R-/-) mice. After inoculation with live attenuated pseudorabies virus (PRV), the mutant mice showed no infectivity titers in various tissues, and transient viral Ag expression only in the spleen, similar as in wild-type mice. However, the absence of the IFN-gamma R resulted in increased proliferative splenocyte responses. The PRV-immune animals showed a normal IFN-gamma and IL-2 production, without detectable IL-4, and with decreased IL-10 secretion in response to viral Ag or Con A. Immunohistochemically, an increased ratio of IFN-gamma:IL-4-producing spleen cells was found. After immunization with either live attenuated or inactivated PRV, IFN-gamma R-/- mice produced significantly less antiviral Ab, and more succumbed to challenge infection than the intact control animals. The reduction in Ab titers in the mutant mice correlated with lower protection by their sera in transfer experiments. Our data demonstrate that ablation of the IFN-gamma receptor surprisingly does not inhibit the generation of antiviral Th1-type and increase Th2-type cytokine responses. However, it profoundly impairs the generation of protective antiviral Ab.

Autoimmune disease: A role for new anti-viral therapies?

PubMed

Dreyfus, David H

2011-12-01

Many chronic human diseases may have an underlying autoimmune mechanism. In this review, the author presents a case of autoimmune CIU (chronic idiopathic urticaria) in stable remission after therapy with a retroviral integrase inhibitor, raltegravir (Isentress). Previous reports located using the search terms "autoimmunity" and "anti-viral" and related topics in the pubmed data-base are reviewed suggesting that novel anti-viral agents such as retroviral integrase inhibitors, gene silencing therapies and eventually vaccines may provide new options for anti-viral therapy of autoimmune diseases. Cited epidemiologic and experimental evidence suggests that increased replication of epigenomic viral pathogens such as Epstein-Barr Virus (EBV) in chronic human autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus Erythematosus (SLE), and multiple sclerosis (MS) may activate endogenous human retroviruses (HERV) as a pathologic mechanism. Memory B cells are the reservoir of infection of EBV and also express endogenous retroviruses, thus depletion of memory b-lymphocytes by monoclonal antibodies (Rituximab) may have therapeutic anti-viral effects in addition to effects on B-lymphocyte presentation of both EBV and HERV superantigens. Other novel anti-viral therapies of chronic autoimmune diseases, such as retroviral integrase inhibitors, could be effective, although not without risk. Copyright © 2011 Elsevier B.V. All rights reserved.

KSHV Targeted Therapy: An Update on Inhibitors of Viral Lytic Replication

PubMed Central

Coen, Natacha; Duraffour, Sophie; Snoeck, Robert; Andrei, Graciela

2014-01-01

Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi’s sarcoma, primary effusion lymphoma and multicentric Castleman’s disease. Since the discovery of KSHV 20 years ago, there is still no standard treatment and the management of virus-associated malignancies remains toxic and incompletely efficacious. As the majority of tumor cells are latently infected with KSHV, currently marketed antivirals that target the virus lytic cycle have shown inconsistent results in clinic. Nevertheless, lytic replication plays a major role in disease progression and virus dissemination. Case reports and retrospective studies have pointed out the benefit of antiviral therapy in the treatment and prevention of KSHV-associated diseases. As a consequence, potent and selective antivirals are needed. This review focuses on the anti-KSHV activity, mode of action and current status of antiviral drugs targeting KSHV lytic cycle. Among these drugs, different subclasses of viral DNA polymerase inhibitors and compounds that do not target the viral DNA polymerase are being discussed. We also cover molecules that target cellular kinases, as well as the potential of new drug targets and animal models for antiviral testing. PMID:25421895

Host Translation Shutoff Mediated by Non-structural Protein 2 is a Critical Factor in the Antiviral State Resistance of Venezuelan Equine Encephalitis Virus

PubMed Central

Bhalla, Nishank; Sun, Chengqun; Lam, L. K. Metthew; Gardner, Christina L.; Ryman, Kate D.; Klimstra, William B.

2016-01-01

Most previous studies of interferon-alpha/beta (IFN-α/β) response antagonism by alphaviruses have focused upon interruption of IFN-α/β induction and/or receptor signaling cascades. Infection of mice with Venezuelan equine encephalitis alphavirus (VEEV) or Sindbis virus (SINV) induces serum IFN-α/β, that elicits a systemic antiviral state in uninfected cells successfully controlling SINV but not VEEV replication. Furthermore, VEEV replication is more resistant than that of SINV to a pre-existing antiviral state in vitro. While host macromolecular shutoff is proposed as a major antagonist of IFN-α/β induction, the underlying mechanisms of alphavirus resistance to a pre-existing antiviral state are not fully defined, nor is the mechanism for the greater resistance of VEEV. Here, we have separated viral transcription and translation shutoff with multiple alphaviruses, identified the viral proteins that induce each activity, and demonstrated that VEEV nonstructural protein 2-induced translation shutoff is likely a critical factor in enhanced antiviral state resistance of this alphavirus. PMID:27318152

Investigation of antiviral state mediated by interferon-inducible transmembrane protein 1 induced by H9N2 virus and inactivated viral particle in human endothelial cells.

PubMed

Feng, Bo; Zhao, Lihong; Wang, Wei; Wang, Jianfang; Wang, Hongyan; Duan, Huiqin; Zhang, Jianjun; Qiao, Jian

2017-11-03

Endothelial cells are believed to play an important role in response to virus infection. Our previous microarray analysis showed that H9N2 virus infection and inactivated viral particle inoculation increased the expression of interferon-inducible transmembrane protein 1 (IFITM1) in human umbilical vein endothelial cells (HUVECs). In present study, we deeply investigated the expression patterns of IFITM1 and IFITM1-mediated antiviral response induced by H9N2 virus infection and inactivated viral particle inoculation in HUVECs. Epithelial cells that are considered target cells of the influenza virus were selected as a reference control. First, we quantified the expression levels of IFITM1 in HUVECs induced by H9N2 virus infection or viral particle inoculation using quantitative real-time PCR and western blot. Second, we observed whether hemagglutinin or neuraminidase affected IFITM1 expression in HUVECs. Finally, we investigated the effect of induced-IFITM1 on the antiviral state in HUVECs by siRNA and activation plasmid transfection. Both H9N2 virus infection and viral particle inoculation increased the expression of IFITM1 without elevating the levels of interferon-ɑ/β in HUVECs. HA or NA protein binding alone is not sufficient to increase the levels of IFITM1 and interferon-ɑ/β in HUVECs. IFITM1 induced by viral particle inoculation significantly decreased the virus titers in culture supernatants of HUVECs. Our results showed that inactivated viral particle inoculation increased the expression of IFITM1 at mRNA and protein levels. Moreover, the induction of IFITM1 expression mediated the antiviral state in HUVECs.

Bovine lactoferrin digested with human gastrointestinal enzymes inhibits replication of human echovirus 5 in cell culture.

PubMed

Furlund, Camilla B; Kristoffersen, Anja B; Devold, Tove G; Vegarud, Gerd E; Jonassen, Christine M

2012-07-01

Many infant formulas are enriched with lactoferrin (Lf) because of its claimed beneficial effects on health. Native bovine Lf (bLf) is known to inhibit in vitro replication of human enteroviruses, a group of pathogenic viruses that replicate in the gut as their primary infection site. On the basis of a model digestion and human gastrointestinal enzymes, we hypothesized that bLf could retain its antiviral properties against enterovirus in the gastrointestinal tract, either as an intact protein or through bioactive peptide fragments released by digestive enzymes. To test our hypothesis, bLf was digested with human gastric juice and duodenal juice in a 2-step in vitro digestion model. Two gastric pH levels and reduction conditions were used to simulate physiological conditions in adults and infants. The antiviral activity of native bLf and of the digested fractions was studied on echovirus 5 in vitro, using various assay conditions, addressing several mechanisms for replication inhibition. Both native and digested bLf fractions revealed a significant inhibitory effect, when added before or simultaneously with the virus onto the cells. Furthermore, a significant stronger sustained antiviral effect was observed when bLf was fully digested in the gastric phase with fast pH reduction to 2.5, compared with native bLf, suggesting the release of antiviral peptides from bLf during the human digestion process. In conclusion, this study demonstrates that bLf may have a role in the prevention of human gastrointestinal virus infection under physiological conditions and that food containing bLf may protect against infection in vivo. Copyright © 2012 Elsevier Inc. All rights reserved.

Cell-Specific IRF-3 Responses Protect against West Nile Virus Infection by Interferon-Dependent and -Independent Mechanisms

PubMed Central

Daffis, Stephane; Samuel, Melanie A; Keller, Brian C; Gale, Michael; Diamond, Michael S

2007-01-01

Interferon regulatory factor (IRF)-3 is a master transcription factor that activates host antiviral defense programs. Although cell culture studies suggest that IRF-3 promotes antiviral control by inducing interferon (IFN)-β, near normal levels of IFN-α and IFN-β were observed in IRF-3−/− mice after infection by several RNA and DNA viruses. Thus, the specific mechanisms by which IRF-3 modulates viral infection remain controversial. Some of this disparity could reflect direct IRF-3-dependent antiviral responses in specific cell types to control infection. To address this and determine how IRF-3 coordinates an antiviral response, we infected IRF-3−/− mice and two primary cells relevant for West Nile virus (WNV) pathogenesis, macrophages and cortical neurons. IRF-3−/− mice were uniformly vulnerable to infection and developed elevated WNV burdens in peripheral and central nervous system tissues, though peripheral IFN responses were largely normal. Whereas wild-type macrophages basally expressed key host defense molecules, including RIG-I, MDA5, ISG54, and ISG56, and restricted WNV infection, IRF-3−/− macrophages lacked basal expression of these host defense genes and supported increased WNV infection and IFN-α and IFN-β production. In contrast, wild-type cortical neurons were highly permissive to WNV and did not basally express RIG-I, MDA5, ISG54, and ISG56. IRF-3−/− neurons lacked induction of host defense genes and had blunted IFN-α and IFN-β production, yet exhibited only modestly increased viral titers. Collectively, our data suggest that cell-specific IRF-3 responses protect against WNV infection through both IFN-dependent and -independent programs. PMID:17676997

Structure-activity relationship studies on a Trp dendrimer with dual activities against HIV and enterovirus A71. Modifications on the amino acid.

PubMed

Martínez-Gualda, Belén; Sun, Liang; Rivero-Buceta, Eva; Flores, Aida; Quesada, Ernesto; Balzarini, Jan; Noppen, Sam; Liekens, Sandra; Schols, Dominique; Neyts, Johan; Leyssen, Pieter; Mirabelli, Carmen; Camarasa, María-José; San-Félix, Ana

2017-03-01

We have recently described a new class of dendrimers with tryptophan (Trp) on the surface that show dual antiviral activities against HIV and EV71 enterovirus. The prototype compound of this family is a pentaerythritol derivative with 12 Trps on the periphery. Here we complete the structure-activity relationship studies of this family to identify key features that might be significant for the antiviral activity. With this aim, novel dendrimers containing different amino acids (aromatic and non-aromatic), tryptamine (a "decarboxylated" analogue of Trp) and N-methyl Trp on the periphery have been prepared. Dendrimer with N-Methyl Trp was the most active against HIV-1 and HIV-2 while dendrimer with tyrosine was endowed with the most potent antiviral activity against EV71. This tyrosine dendrimer proved to inhibit a large panel of EV71 clinical isolates (belonging to different clusters) in the low nanomolar/high picomolar range. In addition, a new synthetic procedure (convergent approach) has been developed for the synthesis of the prototype and some other dendrimers. This convergent approach proved more efficient (higher yields, easier purification) than the divergent approach previously reported. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Design, synthesis, antiviral activity and mode of action of phenanthrene-containing N-heterocyclic compounds inspired by the phenanthroindolizidine alkaloid antofine.

PubMed

Yu, Xiuling; Wei, Peng; Wang, Ziwen; Liu, Yuxiu; Wang, Lizhong; Wang, Qingmin

2016-02-01

The phenanthroindolizidine alkaloid antofine and its analogues have excellent antiviral activity against tobacco mosaic virus (TMV). To simplify the structure and the synthesis of the phenanthroindolizidine alkaloid, a series of phenanthrene-containing N-heterocyclic compounds (compounds 1 to 33) were designed and synthesised, based on the intermolecular interaction of antofine and TMV RNA, and systematically evaluated for their anti-TMV activity. Most of these compounds exhibited good to reasonable anti-TMV activity. The optimum compounds 5, 12 and 21 displayed higher activity than the lead compound antofine and commercial ribavirin. Compound 12 was chosen for field trials of antiviral efficacy against TMV, and was found to exhibit better activity than control plant virus inhibitors. Compounds 5 and 12 were chosen for mode of action studies. The changes in fluorescence intensity of compounds 5 and 12 on separated TMV RNA showed that these small molecules can also bind to TMV RNA, but the mode is very different from that of antofine. The compounds combining phenanthrene and an N-heterocyclic ring could maintain the anti-TMV activity of phenanthroindolizidines, but their modes of action are different from that of antofine. The present study lays a good foundation for us to find more efficient anti-plant virus reagents. © 2015 Society of Chemical Industry.

Polysaccharide and extracts from Lentinula edodes: structural features and antiviral activity

PubMed Central

2012-01-01

Background Lentinula edodes, known as shiitake, has been utilized as food, as well as, in popular medicine, moreover, compounds isolated from its mycelium and fruiting body have shown several therapeutic properties. The aim of this study was to determine the antiviral activity of aqueous (AqE) and ethanol (EtOHE) extracts and polysaccharide (LeP) from Lentinula edodes in the replication of poliovirus type 1 (PV-1) and bovine herpes virus type 1 (BoHV-1). Methods The time-of-addition assay was performed at the times -2, -1, 0, 1 and 2 h of the infection. The virucidal activity and the inhibition of viral adsorption were also evaluated. Plaque assay was used to monitor antiviral activity throughout. Results The AqE and LeP were more effective when added at 0 h of infection, however, EtOHE was more effective at the times 1 h and 2 h of the infection. AqE, EtOHE and LeP showed low virucidal activity, and the inhibition of viral adsorption was not significant. Conclusions The results allowed us to conclude that AqE, EtOHE and LeP act on the initial processes of the replication of both strains of virus. PMID:22336004

Curcumin and Boswellia serrata gum resin extract inhibit chikungunya and vesicular stomatitis virus infections in vitro.

PubMed

von Rhein, Christine; Weidner, Tatjana; Henß, Lisa; Martin, Judith; Weber, Christopher; Sliva, Katja; Schnierle, Barbara S

2016-01-01

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes chikungunya fever and has infected millions of people mainly in developing countries. The associated disease is characterized by rash, high fever, and severe arthritis that can persist for years. CHIKV has adapted to Aedes albopictus, which also inhabits temperate regions including Europe and the United States of America. CHIKV has recently caused large outbreaks in Latin America. No treatment or licensed CHIKV vaccine exists. Traditional medicines are known to have anti-viral effects; therefore, we examined whether curcumin or Boswellia serrata gum resin extract have antiviral activity against CHIKV. Both compounds blocked entry of CHIKV Env-pseudotyped lentiviral vectors and inhibited CHIKV infection in vitro. In addition, vesicular stomatitis virus vector particles and viral infections were also inhibited to the same extent, indicating a broad antiviral activity. Although the bioavailability of these compounds is rather poor, they might be used as a lead structure to develop more effective antiviral drugs or might be used topically to prevent CHIKV spread in the skin after mosquito bites. Copyright © 2015 Elsevier B.V. All rights reserved.

Baicalin from Scutellaria baicalensis blocks respiratory syncytial virus (RSV) infection and reduces inflammatory cell infiltration and lung injury in mice.

PubMed

Shi, Hengfei; Ren, Ke; Lv, Baojie; Zhang, Wei; Zhao, Ying; Tan, Ren Xiang; Li, Erguang

2016-10-21

The roots of Scutellaria baicalensis has been used as a remedy for inflammatory and infective diseases for thousands of years. We evaluated the antiviral activity against respiratory syncytial virus (RSV) infection, the leading cause of childhood infection and hospitalization. By fractionation and chromatographic analysis, we determined that baicalin was responsible for the antiviral activity of S. baicalensis against RSV infection. The concentration for 50% inhibition (IC 50 ) of RSV infection was determined at 19.9 ± 1.8 μM, while the 50% cytotoxic concentration (CC 50 ) was measured at 370 ± 10 μM. We then used a mouse model of RSV infection to further demonstrate baicalin antiviral effect. RSV infection caused significant lung injury and proinflammatory response, including CD4 and CD8 T lymphocyte infiltration. Baicalin treatment resulted in reduction of T lymphocyte infiltration and gene expression of proinflammatory factors, while the treatment moderately reduced RSV titers recovered from the lung tissues. T lymphocyte infiltration and cytotoxic T lymphocyte modulated tissue damage has been identified critical factors of RSV disease. The study therefore demonstrates that baicalin subjugates RSV disease through antiviral and anti-inflammatory effect.

MAVS dimer is a crucial signaling component of innate immunity and the target of hepatitis C virus NS3/4A protease.

PubMed

Baril, Martin; Racine, Marie-Eve; Penin, François; Lamarre, Daniel

2009-02-01

The mitochondrial antiviral signaling (MAVS) protein plays a central role in innate antiviral immunity. Upon recognition of a virus, intracellular receptors of the RIG-I-like helicase family interact with MAVS to trigger a signaling cascade. In this study, we investigate the requirement of the MAVS structure for enabling its signaling by structure-function analyses and resonance energy transfer approaches in live cells. We now report the essential role of the MAVS oligomer in signal transduction and map the transmembrane domain as the main determinant of dimerization. A combination of mutagenesis and computational methods identified a cluster of residues making favorable van der Waals interactions at the MAVS dimer interface. We also correlated the activation of IRF3 and NF-kappaB with MAVS oligomerization rather than its mitochondrial localization. Finally, we demonstrated that MAVS oligomerization is disrupted upon expression of HCV NS3/4A protease, suggesting a mechanism for the loss of antiviral signaling. Altogether, our data suggest that the MAVS oligomer is essential in the formation of a multiprotein membrane-associated signaling complex and enables downstream activation of IRF3 and NF-kappaB in antiviral innate immunity.

In-vitro antiviral activity of Solanum nigrum against Hepatitis C Virus

PubMed Central

2011-01-01

Background Hepatitis C is a major health problem causes liver cirrhosis, hepatocellular carcinoma and death. The current treatment of standard interferon in combination with ribavirin, has limited benefits due to emergence of resistant mutations during long-term treatment, adverse side effects and high cost. Hence, there is a need for the development of more effective, less toxic antiviral agents. Results The present study was designed to search anti-HCV plants from different areas of Pakistan. Ten medicinal plants were collected and tested for anti-HCV activity by infecting the liver cells with HCV 3a innoculum. Methanol and chloroform extracts of Solanum nigrum (SN) seeds exhibited 37% and more than 50% inhibition of HCV respectively at non toxic concentration. Moreover, antiviral effect of SN seeds extract was also analyzed against HCV NS3 protease by transfecting HCV NS3 protease plasmid into liver cells. The results demonstrated that chloroform extract of SN decreased the expression or function of HCV NS3 protease in a dose- dependent manner and GAPDH remained constant. Conclusion These results suggest that SN extract contains potential antiviral agents against HCV and combination of SN extract with interferon will be better option to treat chronic HCV. PMID:21247464

The anti-obesity drug orlistat reveals anti-viral activity.

PubMed

Ammer, Elisabeth; Nietzsche, Sandor; Rien, Christian; Kühnl, Alexander; Mader, Theresa; Heller, Regine; Sauerbrei, Andreas; Henke, Andreas

2015-12-01

The administration of drugs to inhibit metabolic pathways not only reduces the risk of obesity-induced diseases in humans but may also hamper the replication of different viral pathogens. In order to investigate the value of the US Food and Drug Administration-approved anti-obesity drug orlistat in view of its anti-viral activity against different human-pathogenic viruses, several anti-viral studies, electron microscopy analyses as well as fatty acid uptake experiments were performed. The results indicate that administrations of non-cytotoxic concentrations of orlistat reduced the replication of coxsackievirus B3 (CVB3) in different cell types significantly. Moreover, orlistat revealed cell protective effects and modified the formation of multi-layered structures in CVB3-infected cells, which are necessary for viral replication. Lowering fatty acid uptake from the extracellular environment by phloretin administrations had only marginal impact on CVB3 replication. Finally, orlistat reduced also the replication of varicella-zoster virus moderately but had no significant influence on the replication of influenza A viruses. The data support further experiments into the value of orlistat as an inhibitor of the fatty acid synthase to develop new anti-viral compounds, which are based on the modulation of cellular metabolic pathways.

RNA sensor LGP2 inhibits TRAF ubiquitin ligase to negatively regulate innate immune signaling.

PubMed

Parisien, Jean-Patrick; Lenoir, Jessica J; Mandhana, Roli; Rodriguez, Kenny R; Qian, Kenin; Bruns, Annie M; Horvath, Curt M

2018-06-01

The production of type I interferon (IFN) is essential for cellular barrier functions and innate and adaptive antiviral immunity. In response to virus infections, RNA receptors RIG-I and MDA5 stimulate a mitochondria-localized signaling apparatus that uses TRAF family ubiquitin ligase proteins to activate master transcription regulators IRF3 and NFκB, driving IFN and antiviral target gene expression. Data indicate that a third RNA receptor, LGP2, acts as a negative regulator of antiviral signaling by interfering with TRAF family proteins. Disruption of LGP2 expression in cells results in earlier and overactive transcriptional responses to virus or dsRNA LGP2 associates with the C-terminus of TRAF2, TRAF3, TRAF5, and TRAF6 and interferes with TRAF ubiquitin ligase activity. TRAF interference is independent of LGP2 ATP hydrolysis, RNA binding, or its C-terminal domain, and LGP2 can regulate TRAF-mediated signaling pathways in trans , including IL-1β, TNFα, and cGAMP These findings provide a unique mechanism for LGP2 negative regulation through TRAF suppression and extend the potential impact of LGP2 negative regulation beyond the IFN antiviral response. © 2018 The Authors.

Engineering soya bean seeds as a scalable platform to produce cyanovirin-N, a non-ARV microbicide against HIV.

PubMed

O'Keefe, Barry R; Murad, André M; Vianna, Giovanni R; Ramessar, Koreen; Saucedo, Carrie J; Wilson, Jennifer; Buckheit, Karen W; da Cunha, Nicolau B; Araújo, Ana Claudia G; Lacorte, Cristiano C; Madeira, Luisa; McMahon, James B; Rech, Elibio L

2015-09-01

There is an urgent need to provide effective anti-HIV microbicides to resource-poor areas worldwide. Some of the most promising microbicide candidates are biotherapeutics targeting viral entry. To provide biotherapeutics to poorer areas, it is vital to reduce the cost. Here, we report the production of biologically active recombinant cyanovirin-N (rCV-N), an antiviral protein, in genetically engineered soya bean seeds. Pure, biologically active rCV-N was isolated with a yield of 350 μg/g of dry seed weight. The observed amino acid sequence of rCV-N matched the expected sequence of native CV-N, as did the mass of rCV-N (11 009 Da). Purified rCV-N from soya is active in anti-HIV assays with an EC50 of 0.82-2.7 nM (compared to 0.45-1.8 nM for E. coli-produced CV-N). Standard industrial processing of soya bean seeds to harvest soya bean oil does not diminish the antiviral activity of recovered rCV-N, allowing the use of industrial soya bean processing to generate both soya bean oil and a recombinant protein for anti-HIV microbicide development. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Immune Receptors and Co-receptors in Antiviral Innate Immunity in Plants.

PubMed

Gouveia, Bianca C; Calil, Iara P; Machado, João Paulo B; Santos, Anésia A; Fontes, Elizabeth P B

2016-01-01

Plants respond to pathogens using an innate immune system that is broadly divided into PTI (pathogen-associated molecular pattern- or PAMP-triggered immunity) and ETI (effector-triggered immunity). PTI is activated upon perception of PAMPs, conserved motifs derived from pathogens, by surface membrane-anchored pattern recognition receptors (PRRs). To overcome this first line of defense, pathogens release into plant cells effectors that inhibit PTI and activate effector-triggered susceptibility (ETS). Counteracting this virulence strategy, plant cells synthesize intracellular resistance (R) proteins, which specifically recognize pathogen effectors or avirulence (Avr) factors and activate ETI. These coevolving pathogen virulence strategies and plant resistance mechanisms illustrate evolutionary arms race between pathogen and host, which is integrated into the zigzag model of plant innate immunity. Although antiviral immune concepts have been initially excluded from the zigzag model, recent studies have provided several lines of evidence substantiating the notion that plants deploy the innate immune system to fight viruses in a manner similar to that used for non-viral pathogens. First, most R proteins against viruses so far characterized share structural similarity with antibacterial and antifungal R gene products and elicit typical ETI-based immune responses. Second, virus-derived PAMPs may activate PTI-like responses through immune co-receptors of plant PTI. Finally, and even more compelling, a viral Avr factor that triggers ETI in resistant genotypes has recently been shown to act as a suppressor of PTI, integrating plant viruses into the co-evolutionary model of host-pathogen interactions, the zigzag model. In this review, we summarize these important progresses, focusing on the potential significance of antiviral immune receptors and co-receptors in plant antiviral innate immunity. In light of the innate immune system, we also discuss a newly uncovered layer of antiviral defense that is specific to plant DNA viruses and relies on transmembrane receptor-mediated translational suppression for defense.

RNase L targets distinct sites in influenza A virus RNAs.

PubMed

Cooper, Daphne A; Banerjee, Shuvojit; Chakrabarti, Arindam; García-Sastre, Adolfo; Hesselberth, Jay R; Silverman, Robert H; Barton, David J

2015-03-01

Influenza A virus (IAV) infections are influenced by type 1 interferon-mediated antiviral defenses and by viral countermeasures to these defenses. When IAV NS1 protein is disabled, RNase L restricts virus replication; however, the RNAs targeted for cleavage by RNase L under these conditions have not been defined. In this study, we used deep-sequencing methods to identify RNase L cleavage sites within host and viral RNAs from IAV PR8ΔNS1-infected A549 cells. Short hairpin RNA knockdown of RNase L allowed us to distinguish between RNase L-dependent and RNase L-independent cleavage sites. RNase L-dependent cleavage sites were evident at discrete locations in IAV RNA segments (both positive and negative strands). Cleavage in PB2, PB1, and PA genomic RNAs suggests that viral RNPs are susceptible to cleavage by RNase L. Prominent amounts of cleavage mapped to specific regions within IAV RNAs, including some areas of increased synonymous-site conservation. Among cellular RNAs, RNase L-dependent cleavage was most frequent at precise locations in rRNAs. Our data show that RNase L targets specific sites in both host and viral RNAs to restrict influenza virus replication when NS1 protein is disabled. RNase L is a critical component of interferon-regulated and double-stranded-RNA-activated antiviral host responses. We sought to determine how RNase L exerts its antiviral activity during influenza virus infection. We enhanced the antiviral activity of RNase L by disabling a viral protein, NS1, that inhibits the activation of RNase L. Then, using deep-sequencing methods, we identified the host and viral RNAs targeted by RNase L. We found that RNase L cleaved viral RNAs and rRNAs at very precise locations. The direct cleavage of IAV RNAs by RNase L highlights an intimate battle between viral RNAs and an antiviral endonuclease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The Antiviral Alkaloid Berberine Reduces Chikungunya Virus-Induced Mitogen-Activated Protein Kinase Signaling

PubMed Central

Thaa, Bastian; Amrun, Siti Naqiah; Simarmata, Diane; Rausalu, Kai; Nyman, Tuula A.; Merits, Andres; McInerney, Gerald M.; Ng, Lisa F. P.

2016-01-01

ABSTRACT Chikungunya virus (CHIKV) has infected millions of people in the tropical and subtropical regions since its reemergence in the last decade. We recently identified the nontoxic plant alkaloid berberine as an antiviral substance against CHIKV in a high-throughput screen. Here, we show that berberine is effective in multiple cell types against a variety of CHIKV strains, also at a high multiplicity of infection, consolidating the potential of berberine as an antiviral drug. We excluded any effect of this compound on virus entry or on the activity of the viral replicase. A human phosphokinase array revealed that CHIKV infection specifically activated the major mitogen-activated protein kinase (MAPK) signaling pathways extracellular signal-related kinase (ERK), p38 and c-Jun NH2-terminal kinase (JNK). Upon treatment with berberine, this virus-induced MAPK activation was markedly reduced. Subsequent analyses with specific inhibitors of these kinases indicated that the ERK and JNK signaling cascades are important for the generation of progeny virions. In contrast to specific MAPK inhibitors, berberine lowered virus-induced activation of all major MAPK pathways and resulted in a stronger reduction in viral titers. Further, we assessed the in vivo efficacy of berberine in a mouse model and measured a significant reduction of CHIKV-induced inflammatory disease. In summary, we demonstrate the efficacy of berberine as a drug against CHIKV and highlight the importance of the MAPK signaling pathways in the alphavirus infectious cycle. IMPORTANCE Chikungunya virus (CHIKV) is a mosquito-borne virus that causes severe and persistent muscle and joint pain and has recently spread to the Americas. No licensed drug exists to counter this virus. In this study, we report that the alkaloid berberine is antiviral against different CHIKV strains and in multiple human cell lines. We demonstrate that berberine collectively reduced the virus-induced activation of cellular mitogen-activated protein kinase signaling. The relevance of these signaling cascades in the viral life cycle was emphasized by specific inhibitors of these kinase pathways, which decreased the production of progeny virions. Berberine significantly reduced CHIKV-induced inflammatory disease in a mouse model, demonstrating efficacy of the drug in vivo. Overall, this work makes a strong case for pursuing berberine as a potential anti-CHIKV therapeutic compound and for exploring the MAPK signaling pathways as antiviral targets against alphavirus infections. PMID:27535052

Discovery of Multitarget Agents Active as Broad-Spectrum Antivirals and Correctors of Cystic Fibrosis Transmembrane Conductance Regulator for Associated Pulmonary Diseases.

PubMed

Tassini, Sabrina; Sun, Liang; Lanko, Kristina; Crespan, Emmanuele; Langron, Emily; Falchi, Federico; Kissova, Miroslava; Armijos-Rivera, Jorge I; Delang, Leen; Mirabelli, Carmen; Neyts, Johan; Pieroni, Marco; Cavalli, Andrea; Costantino, Gabriele; Maga, Giovanni; Vergani, Paola; Leyssen, Pieter; Radi, Marco

2017-02-23

Enteroviruses (EVs) are among the most frequent infectious agents in humans worldwide and represent the leading cause of upper respiratory tract infections. No drugs for the treatment of EV infections are currently available. Recent studies have also linked EV infection with pulmonary exacerbations, especially in cystic fibrosis (CF) patients, and the importance of this link is probably underestimated. The aim of this work was to develop a new class of multitarget agents active both as broad-spectrum antivirals and as correctors of the F508del-cystic fibrosis transmembrane conductance regulator (CFTR) folding defect responsible for >90% of CF cases. We report herein the discovery of the first small molecules able to simultaneously act as correctors of the F508del-CFTR folding defect and as broad-spectrum antivirals against a panel of EVs representative of all major species.

A review of antiviral drugs and other compounds with activity against feline herpesvirus-1

PubMed Central

Thomasy, S. M.; Maggs, D. J.

2016-01-01

Feline herpesvirus type 1 (FHV-1) is a common and important cause of ocular surface disease, dermatitis, respiratory disease, and potentially intraocular disease in cats. However, many antiviral drugs developed for the treatment of humans infected with herpesviruses have been used to treat cats infected with FHV-1. Translational use of drugs in this manner ideally requires methodical investigation of their in vitro efficacy against FHV-1 followed by pharmacokinetic and safety trials in normal cats. Subsequently, placebo-controlled efficacy studies in experimentally-inoculated animals should be performed followed, finally, by carefully designed and monitored clinical trials in client-owned animals. This review is intended to provide a concise review of the available literature regarding the efficacy of antiviral drugs and other compounds with proven or putative activity against FHV-1, as well as a discussion of their safety in cats. PMID:27091747

Synthetic RNAs Mimicking Structural Domains in the Foot-and-Mouth Disease Virus Genome Elicit a Broad Innate Immune Response in Porcine Cells Triggered by RIG-I and TLR Activation.

PubMed

Borrego, Belén; Rodríguez-Pulido, Miguel; Revilla, Concepción; Álvarez, Belén; Sobrino, Francisco; Domínguez, Javier; Sáiz, Margarita

2015-07-17

The innate immune system is the first line of defense against viral infections. Exploiting innate responses for antiviral, therapeutic and vaccine adjuvation strategies is being extensively explored. We have previously described, the ability of small in vitro RNA transcripts, mimicking the sequence and structure of different domains in the non-coding regions of the foot-and-mouth disease virus (FMDV) genome (ncRNAs), to trigger a potent and rapid innate immune response. These synthetic non-infectious molecules have proved to have a broad-range antiviral activity and to enhance the immunogenicity of an FMD inactivated vaccine in mice. Here, we have studied the involvement of pattern-recognition receptors (PRRs) in the ncRNA-induced innate response and analyzed the antiviral and cytokine profiles elicited in swine cultured cells, as well as peripheral blood mononuclear cells (PBMCs).

Light-activated nanotube-porphyrin conjugates as effective antiviral agents

NASA Astrophysics Data System (ADS)

Banerjee, Indrani; Douaisi, Marc P.; Mondal, Dhananjoy; Kane, Ravi S.

2012-03-01

Porphyrins have been used for photodynamic therapy (PDT) against a wide range of targets like bacteria, viruses and tumor cells. In this work, we report porphyrin-conjugated multi-walled carbon nanotubes (NT-P) as potent antiviral agents. Specifically, we used Protoporphyrin IX (PPIX), which we attached to acid-functionalized multi-walled carbon nanotubes (MWNTs). We decided to use carbon nanotubes as scaffolds because of their ease of recovery from a solution through filtration. In the presence of visible light, NT-P was found to significantly reduce the ability of Influenza A virus to infect mammalian cells. NT-P may be used effectively against influenza viruses with little or no chance of them developing resistance to the treatment. Furthermore, NT-P can be easily recovered through filtration which offers a facile strategy to reuse the active porphyrin moiety to its fullest extent. Thus NT-P conjugates represent a new approach for preparing ex vivo reusable antiviral agents.

ATM facilitates mouse gammaherpesvirus reactivation from myeloid cells during chronic infection

PubMed Central

Kulinski, Joseph M.; Darrah, Eric J.; Broniowska, Katarzyna A.; Mboko, Wadzanai P.; Mounce, Bryan C.; Malherbe, Laurent P.; Corbett, John A; Gauld, Stephen B.; Tarakanova, Vera L.

2015-01-01

Gammaherpesviruses are cancer-associated pathogens that establish life-long infection in most adults. Insufficiency of Ataxia-Telangiectasia mutated (ATM) kinase leads to a poor control of chronic gammaherpesvirus infection via an unknown mechanism that likely involves a suboptimal antiviral response. In contrast to the phenotype in the intact host, ATM facilitates gammaherpesvirus reactivation and replication in vitro. We hypothesized that ATM mediates both pro- and antiviral activities to regulate chronic gammaherpesvirus infection in an immunocompetent host. To test the proposed proviral activity of ATM in vivo, we generated mice with ATM deficiency limited to myeloid cells. Myeloid-specific ATM deficiency attenuated gammaherpesvirus infection during the establishment of viral latency. The results of our study uncover a proviral role of ATM in the context of gammaherpesvirus infection in vivo and support a model where ATM combines pro- and antiviral functions to facilitate both gammaherpesvirus-specific T cell immune response and viral reactivation in vivo. PMID:26001649

OAS and PKR are not Required for the Anti-viral Effect of Ad:IFN-γ Against Acute HSV-1 in Primary Trigeminal Ganglia Cultures

PubMed Central

Austin, Bobbie Ann; Halford, William; Silverman, Robert H.; Williams, Bryan R. G.; Carr, Daniel J. J.

2005-01-01

Three interferon-gamma (IFNG) induced anti-viral pathways have been reported. Involved anti-viral proteins include: Mx, RNaseL/2'-5'-OAS, and PKR. Involvement of OAS and PKR in IFNG-induced anti-HSV-1 pathways has not been previously reported, but IFNG induces OAS and PKR when other viruses invade the nervous system. The aim of the current study was to determine whether the absence of intact OAS and PKR anti-viral pathways affect the anti-viral activity of IFNG during acute HSV-1 infection within trigeminal ganglia (TG). To investigate this, primary TG cultures were established using TGs removed from C57BL/6 (Wt), RNase L knockout, and RNase L/PKR double knockout mice. Each dissociated TG was transduced with an adenoviral vector containing an IFNG transgene or vector alone. Viral titers following HSV-1 infection of primary TG cell cultures were determined. Significant differences in viral titer for Ad:Null versus Ad:IFNG tranduced TGs were found in each genotype. However, the effectiveness of Ad:IFNG was not reduced in the absence of both OAS and PKR pathways or OAS alone. Recombinant IFNG also exhibited anti-HSV-1 activity. The effectiveness of the IFNG transgene was lost in primary TG cells from IFNG receptor knockout mice. The data suggest that novel anti-HSV-1 mechanisms are induced by IFNG. PMID:16704298

Exploration of (hetero)aryl derived thienylchalcones for antiviral and anticancer activities.

PubMed

Patil, Vikrant; Patil, Siddappa A; Patil, Renukadevi; Bugarin, Alejandro; Beaman, Kenneth; Patil, Shivaputra A

2018-05-23

Search for new antiviral and anticancer agents are essential because of the emergence of drug resistance in recent years. In continuation of our efforts in identifying the new small molecule antiviral and anticancer agents, we identified chalcones as potent antiviral and anticancer agents. With the aim of identifying the broad acting antiviral and anticancer agents, we discovered substituted aryl/heteroaryl derived thienyl chalcones as antiviral and anticancer agents. A focused set of thienyl chalcone derivaties II-VI was screened for selected viruses Hepatitis B virus (HBV), Herpes simplex virus 1 (HSV-1), Human cytomegalovirus (HCMV), Dengue virus 2 (DENV2), Influenza A (H1N1) virus, MERS coronavirus, Poliovirus 1 (PV 1), Rift Valley fever (RVF), Tacaribe virus (TCRV), Venezuelan equine encephalitis virus (VEE) and Zika virus (ZIKV) using the National Institute of Allergy and Infectious Diseases (NIAID)'s Division of Microbiology and Infectious Diseases (DMID) antiviral screening program. Additionally, a cyclopropylquinoline derivative IV has been screened for 60 human cancer cell lines using the Development Therapeutics Program (DTP) of NCI. All thienyl chalcone derivatives II-VI displayed moderate to excellent antiviral activity towards several viruses tested. Compounds V and VI were turned out be active compounds towards human cytomegalovirus for both normal strain (AD169) as well as resistant isolate (GDGr K17). Particularly, cyano derivative V showed very high potency (EC50: <0.05 µM) towards AD169 strain of HCMV compared to standard drug Ganciclovir (EC50: 0.12 µM). Additionally, it showed moderate activity in the secondary assay (AD169; EC50: 2.30 µM). The cyclopropylquinoline derivative IV displayed high potency towards Rift Valley fever virus (RVFV) and Tacaribe virus (TCRV). The cyclopropylquinoline derivative IV is nearly 28 times more potent in our initial in vitro visual assay (EC50: 0.39 μg/ml) and nearly 17 times more potent in neutral red assay (EC50: 0.71 μg/ml) compared to the standard drug Ribavirin (EC50: 11 μg/ml; visual assay and EC50: 12 μg/ml; neutral red assay). It is nearly 12 times more potent in our initial in vitro visual assay (EC50: >1 μg/ml) and nearly 8 times more potent in neutral red assay (EC50: >1.3 μg/ml) compared to the standard drug Ribavirin (EC50: 12 μg/ml; visual assay and EC50: 9.9 μg/ml; neutral red assay) towards Tacaribe virus (TCRV). Additionally, cyclopropylquinoline derivative IV has shown strong growth inhibitory activity towards three major cancer (colon, breast, and leukemia) cell lines and moderate growth inhibition shown towards other cancer cell lines screened. Compounds V and VI were demonstrated viral inhibition towards Human cytomegalovirus, whereas cyclopropylquinoline derivative IV towards Rift Valley fever virus and Tacaribe virus. Additionally, cyclopropylquinoline derivative IV has displayed very good cytotoxicity against colon, breast and leukemia cell lines in vitro. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Chitosan-induced antiviral activity and innate immunity in plants.

PubMed

Iriti, Marcello; Varoni, Elena Maria

2015-02-01

Immunity represents a trait common to all living organisms, and animals and plants share some similarities. Therefore, in susceptible host plants, complex defence machinery may be stimulated by elicitors. Among these, chitosan deserves particular attention because of its proved efficacy. This survey deals with the antiviral activity of chitosan, focusing on its perception by the plant cell and mechanism of action. Emphasis has been paid to benefits and limitations of this strategy in crop protection, as well as to the potential of chitosan as a promising agent in virus disease control.

Synthesis, cytotoxic effect and antiviral activity of 1-(beta-D-arabinofuranosyl)-5-bromo-N4-substituted cytosine and 1-(beta-D-arabinofuranosyl)-5-bromo-4-methoxypyrimidin-2(1H)-one derivatives.

PubMed

Saladino, R; Mezzetti, M; Mincione, E; Palamara, A T; Savini, P; Marini, S

1999-01-01

A convenient and mild synthesis of 5-bromo-N4-substituted-1-(beta-D-arabinofuranosyl)cytosine and 5-bromo-O4-methyl-1-(beta-D-arabinofuranosyl)pyrimidin-2(1H)-one derivatives by selective oxyfunctionalization of the corresponding 4-thionucleosides with 3,3-dimethyldioxirane is reported. The cytotoxicity and the antiviral activity against parainfluenza 1 (Sendai virus) of all new synthesized products are also reported.

Vaccinia Virus Blocks Stat1-Dependent and Stat1-Independent Gene Expression Induced by Type I and Type II Interferons

PubMed Central

Mann, Brandon A.; Huang, Julia He; Li, Ping; Chang, Hua-Chen; Slee, Roger B.; O'Sullivan, Audrey; Mathur, Anita; Yeh, Norman; Klemsz, Michael J.; Brutkiewicz, Randy R.; Blum, Janice S.

2008-01-01

Blocking the function of Stat (signal transducer and activator of transcription) proteins, which are critical for antiviral responses, has evolved as a common mechanism for pathogen immune evasion. The poxvirus-encoded phosphatase H1 is critical for viral replication, and may play an additional role in the evasion of host defense by dephosphorylating Stat1 and blocking interferon (IFN)-stimulated innate immune responses. Vaccinia virus (VACV) H1 can inhibit the phosphorylation of the transcription factor Stat1 after IFN-γ stimulation of epithelial cells, greatly attenuating IFN-induced biological functions. In this study, we demonstrate that VACV infection is capable of inhibiting the phosphorylation of Stat1 and Stat2 after stimulation of fibroblasts or bone marrow-derived macrophages with either type I or type II IFNs, but did not inhibit the activation of Stat3 or Stat5 in either cell type. By using recombinant proteins for in vitro assays, we observe that variola virus H1 is more active than VACV H1, although it has similar selectivity for Stat targets. Differential effects of VACV infection were observed on the induction of IFN-stimulated genes, with complete inhibition of some genes by VACV infection, while others were less affected. Despite the IFN-γ-induced expression of some genes in VACV-infected cells, IFN-γ was unable to rescue the VACV-mediated inhibition of MHC class II antigen presentation. Moreover, VACV infection can affect the IFN-induced expression of Stat1-dependent and Stat1-independent genes, suggesting that the virus may target additional IFN-activated pathways. Thus, VACV targets multiple signaling pathways in the evasion of antiviral immune responses. PMID:18593332

Antiviral activity of casein and αs2 casein hydrolysates against the infectious haematopoietic necrosis virus, a rhabdovirus from salmonid fish.

PubMed

Rodríguez Saint-Jean, S; De las Heras, A; Carrillo, W; Recio, I; Ortiz-Delgado, J B; Ramos, M; Gomez-Ruiz, J A; Sarasquete, C; Pérez-Prieto, S I

2013-05-01

Salmonid fish viruses, such as infectious haematopoietic necrosis virus (IHNV), are responsible for serious losses in the rainbow trout and salmon-farming industries, and they have been the subject of intense research in the field of aquaculture. Thus, the aim of this work is to study the antiviral effect of milk-derived proteins as bovine caseins or casein-derived peptides at different stages during the course of IHNV infection. The results indicate that the 3-h fraction of casein and α(S2) -casein hydrolysates reduced the yield of infectious IHNV in a dose-dependent manner and impaired the production of IHNV-specific antigens. Hydrolysates of total casein and α(S2) -casein target the initial and later stages of viral infection, as demonstrated by the reduction in the infective titre observed throughout multiple stages and cycles. In vivo, more than 50% protection was observed in the casein-treated fish, and the kidney sections exhibited none of the histopathological characteristics of IHNV infection. The active fractions from casein were identified, as well as one of the individual IHNV-inhibiting peptides. Further studies will be required to determine which other peptides possess this activity. These findings provide a basis for future investigations on the efficacy of these compounds in treating other viral diseases in farmed fish and to elucidate the underlying molecular mechanisms of action. However, the present results provide convincing evidence in support of a role for several milk casein fractions as suitable candidates to prevent and treat some fish viral infections. © 2012 Blackwell Publishing Ltd.

Viral Evasion of Natural Killer Cell Activation

PubMed Central

Ma, Yi; Li, Xiaojuan; Kuang, Ersheng

2016-01-01

Natural killer (NK) cells play a key role in antiviral innate defenses because of their abilities to kill infected cells and secrete regulatory cytokines. Additionally, NK cells exhibit adaptive memory-like antigen-specific responses, which represent a novel antiviral NK cell defense mechanism. Viruses have evolved various strategies to evade the recognition and destruction by NK cells through the downregulation of the NK cell activating receptors. Here, we review the recent findings on viral evasion of NK cells via the impairment of NK cell-activating receptors and ligands, which provide new insights on the relationship between NK cells and viral actions during persistent viral infections. PMID:27077876

Viral Evasion of Natural Killer Cell Activation.

PubMed

Ma, Yi; Li, Xiaojuan; Kuang, Ersheng

2016-04-12

Natural killer (NK) cells play a key role in antiviral innate defenses because of their abilities to kill infected cells and secrete regulatory cytokines. Additionally, NK cells exhibit adaptive memory-like antigen-specific responses, which represent a novel antiviral NK cell defense mechanism. Viruses have evolved various strategies to evade the recognition and destruction by NK cells through the downregulation of the NK cell activating receptors. Here, we review the recent findings on viral evasion of NK cells via the impairment of NK cell-activating receptors and ligands, which provide new insights on the relationship between NK cells and viral actions during persistent viral infections.

Antiviral activity and synthesis of quaternized promazine derivatives against HSV-1.

PubMed

Purohit, Akasha K; Balish, Matthew D; Leichty, Jacob J; Roe, Ashley; Ward, Lori M; Mitchell, Miguel O; Hsia, Shao-chung

2012-08-15

N-(4-chlorobenzyl)triflupromazinium chloride, a known antitubercular agent, has been found to also be active against HSV-1. A preliminary structure-activity relation has been explored to determine which groups are crucial to viral inhibition. Antiviral assessments such as GFP reduction, plaque reduction, treatment timing and wash-out studies have also been probed to determine a mode of action for QPD-1. Based on this preliminary data, it appears that QPD-1 is a reversible inhibitor, suspected to inhibit early stages of viral replication of HSV-1 at 50 μM, equipotent to acyclovir. Copyright © 2012 Elsevier Ltd. All rights reserved.

Antiviral treatment is more effective than smallpox vaccination upon lethal monkeypox virus infection.

PubMed

Stittelaar, Koert J; Neyts, Johan; Naesens, Lieve; van Amerongen, Geert; van Lavieren, Rob F; Holý, Antonin; De Clercq, Erik; Niesters, Hubert G M; Fries, Edwin; Maas, Chantal; Mulder, Paul G H; van der Zeijst, Ben A M; Osterhaus, Albert D M E

2006-02-09

There is concern that variola virus, the aetiological agent of smallpox, may be used as a biological weapon. For this reason several countries are now stockpiling (vaccinia virus-based) smallpox vaccine. Although the preventive use of smallpox vaccination has been well documented, little is known about its efficacy when used after exposure to the virus. Here we compare the effectiveness of (1) post-exposure smallpox vaccination and (2) antiviral treatment with either cidofovir (also called HPMPC or Vistide) or with a related acyclic nucleoside phosphonate analogue (HPMPO-DAPy) after lethal intratracheal infection of cynomolgus monkeys (Macaca fascicularis) with monkeypox virus (MPXV). MPXV causes a disease similar to human smallpox and this animal model can be used to measure differences in the protective efficacies of classical and new-generation candidate smallpox vaccines. We show that initiation of antiviral treatment 24 h after lethal intratracheal MPXV infection, using either of the antiviral agents and applying various systemic treatment regimens, resulted in significantly reduced mortality and reduced numbers of cutaneous monkeypox lesions. In contrast, when monkeys were vaccinated 24 h after MPXV infection, using a standard human dose of a currently recommended smallpox vaccine (Elstree-RIVM), no significant reduction in mortality was observed. When antiviral therapy was terminated 13 days after infection, all surviving animals had virus-specific serum antibodies and antiviral T lymphocytes. These data show that adequate preparedness for a biological threat involving smallpox should include the possibility of treating exposed individuals with antiviral compounds such as cidofovir or other selective anti-poxvirus drugs.

Antiviral treatment of feline immunodeficiency virus-infected cats with (R)-9-(2-phosphonylmethoxypropyl)-2,6-diaminopurine.

PubMed

Taffin, Elien; Paepe, Dominique; Goris, Nesya; Auwerx, Joeri; Debille, Mariella; Neyts, Johan; Van de Maele, Isabel; Daminet, Sylvie

2015-02-01

Feline immunodeficiency virus (FIV), the causative agent of an acquired immunodeficiency syndrome in cats (feline AIDS), is a ubiquitous health threat to the domestic and feral cat population, also triggering disease in wild animals. No registered antiviral compounds are currently available to treat FIV-infected cats. Several human antiviral drugs have been used experimentally in cats, but not without the development of serious adverse effects. Here we report on the treatment of six naturally FIV-infected cats, suffering from moderate to severe disease, with the antiretroviral compound (R)-9-(2-phosphonylmethoxypropyl)-2,6-diaminopurine ([R]-PMPDAP), a close analogue of tenofovir, a widely prescribed anti-HIV drug in human medicine. An improvement in the average Karnofsky score (pretreatment 33.2 ± 9.4%, post-treatment 65±12.3%), some laboratory parameters (ie, serum amyloid A and gammaglobulins) and a decrease of FIV viral load in plasma were noted in most cats. The role of concurrent medication in ameliorating the Karnofsky score, as well as the possible development of haematological side effects, are discussed. Side effects, when noted, appeared mild and reversible upon cessation of treatment. Although strong conclusions cannot be drawn owing to the small number of patients and lack of a placebo-treated control group, the activity of (R)-PMPDAP, as observed here, warrants further investigation. © ISFM and AAFP 2014.

Abalone Hemocyanin Blocks the Entry of Herpes Simplex Virus 1 into Cells: a Potential New Antiviral Strategy

PubMed Central

Talaei Zanjani, Negar; Miranda-Saksena, Monica; Valtchev, Peter; Hueston, Linda; Diefenbach, Eve; Sairi, Fareed; Gomes, Vincent G.

2015-01-01

A marine-derived compound, abalone hemocyanin, from Haliotis rubra was shown to have a unique mechanism of antiviral activity against herpes simplex virus 1 (HSV-1) infections. In vitro assays demonstrated the dose-dependent and inhibitory effect of purified hemocyanin against HSV-1 infection in Vero cells with a 50% effective dose (ED50) of 40 to 50 nM and no significant toxicity. In addition, hemocyanin specifically inhibited viral attachment and entry by binding selectively to the viral surface glycoproteins gD, gB, and gC, probably by mimicking their receptors. However, hemocyanin had no effect on postentry events and did not block infection by binding to cellular receptors for HSV. By the use of different mutants of gD and gB and a competitive heparin binding assay, both protein charge and conformation were shown to be the driving forces of the interaction between hemocyanin and viral glycoproteins. These findings also suggested that hemocyanin may have different motifs for binding to each of the viral glycoproteins B and D. The dimer subunit of hemocyanin with a 10-fold-smaller molecular mass exhibited similar binding to viral surface glycoproteins, showing that the observed inhibition did not require the entire multimer. Therefore, a small hemocyanin analogue could serve as a new antiviral candidate for HSV infections. PMID:26643336

Murine Efficacy and Pharmacokinetic Evaluation of the Flaviviral NS5 Capping Enzyme 2-Thioxothiazolidin-4-One Inhibitor BG-323

PubMed Central

Bullard, Kristen M.; Gullberg, Rebekah C.; Soltani, Elnaz; Steel, J. Jordan; Geiss, Brian J.; Keenan, Susan M.

2015-01-01

Arthropod-borne flavivirus infection continues to cause significant morbidity and mortality worldwide. Identification of drug targets and novel antiflaviviral compounds to treat these diseases has become a global health imperative. A previous screen of 235,456 commercially available small molecules identified the 2-thioxothiazolidin-4-one family of compounds as inhibitors of the flaviviral NS5 capping enzyme, a promising target for antiviral drug development. Rational drug design methodologies enabled identification of lead compound BG-323 from this series. We have shown previously that BG-323 potently inhibits NS5 capping enzyme activity, displays antiviral effects in dengue virus replicon assays and inhibits growth of West Nile and yellow fever viruses with low cytotoxicity in vitro. In this study we further characterized BG-323’s antiviral activity in vitro and in vivo. We found that BG-323 was able to reduce replication of WNV (NY99) and Powassan viruses in culture, and we were unable to force resistance into WNV (Kunjin) in long-term culture experiments. We then evaluated the antiviral activity of BG-323 in a murine model. Mice were challenged with WNV NY99 and administered BG-323 or mock by IP inoculation immediately post challenge and twice daily thereafter. Mice were bled and viremia was quantified on day three. No significant differences in viremia were observed between BG-323-treated and control groups and clinical scores indicated both BG-323-treated and control mice developed signs of illness on approximately the same day post challenge. To determine whether differences in in vitro and in vivo efficacy were due to unfavorable pharmacokinetic properties of BG-323, we conducted a pharmacokinetic evaluation of this small molecule. Insights from pharmacokinetic studies indicate that BG-323 is cell permeable, has a low efflux ratio and does not significantly inhibit two common cytochrome P450 (CYP P450) isoforms thus suggesting this molecule may be less likely to cause adverse drug interactions. However, the T1/2 of BG-323 was suboptimal and the percent of drug bound to plasma binding proteins was high. Future studies with BG-323 will be aimed at increasing the T1/2 and determining strategies for mitigating the effects of high plasma protein binding, which likely contribute to low in vivo efficacy. PMID:26075394

Murine Efficacy and Pharmacokinetic Evaluation of the Flaviviral NS5 Capping Enzyme 2-Thioxothiazolidin-4-One Inhibitor BG-323.

PubMed

Bullard, Kristen M; Gullberg, Rebekah C; Soltani, Elnaz; Steel, J Jordan; Geiss, Brian J; Keenan, Susan M

2015-01-01

Arthropod-borne flavivirus infection continues to cause significant morbidity and mortality worldwide. Identification of drug targets and novel antiflaviviral compounds to treat these diseases has become a global health imperative. A previous screen of 235,456 commercially available small molecules identified the 2-thioxothiazolidin-4-one family of compounds as inhibitors of the flaviviral NS5 capping enzyme, a promising target for antiviral drug development. Rational drug design methodologies enabled identification of lead compound BG-323 from this series. We have shown previously that BG-323 potently inhibits NS5 capping enzyme activity, displays antiviral effects in dengue virus replicon assays and inhibits growth of West Nile and yellow fever viruses with low cytotoxicity in vitro. In this study we further characterized BG-323's antiviral activity in vitro and in vivo. We found that BG-323 was able to reduce replication of WNV (NY99) and Powassan viruses in culture, and we were unable to force resistance into WNV (Kunjin) in long-term culture experiments. We then evaluated the antiviral activity of BG-323 in a murine model. Mice were challenged with WNV NY99 and administered BG-323 or mock by IP inoculation immediately post challenge and twice daily thereafter. Mice were bled and viremia was quantified on day three. No significant differences in viremia were observed between BG-323-treated and control groups and clinical scores indicated both BG-323-treated and control mice developed signs of illness on approximately the same day post challenge. To determine whether differences in in vitro and in vivo efficacy were due to unfavorable pharmacokinetic properties of BG-323, we conducted a pharmacokinetic evaluation of this small molecule. Insights from pharmacokinetic studies indicate that BG-323 is cell permeable, has a low efflux ratio and does not significantly inhibit two common cytochrome P450 (CYP P450) isoforms thus suggesting this molecule may be less likely to cause adverse drug interactions. However, the T1/2 of BG-323 was suboptimal and the percent of drug bound to plasma binding proteins was high. Future studies with BG-323 will be aimed at increasing the T1/2 and determining strategies for mitigating the effects of high plasma protein binding, which likely contribute to low in vivo efficacy.

Interferon-λ restricts West Nile virus neuroinvasion by tightening the blood-brain barrier.

PubMed

Lazear, Helen M; Daniels, Brian P; Pinto, Amelia K; Huang, Albert C; Vick, Sarah C; Doyle, Sean E; Gale, Michael; Klein, Robyn S; Diamond, Michael S

2015-04-22

Although interferon-λ [also known as type III interferon or interleukin-28 (IL-28)/IL-29] restricts infection by several viruses, its inhibitory mechanism has remained uncertain. We used recombinant interferon-λ and mice lacking the interferon-λ receptor (IFNLR1) to evaluate the effect of interferon-λ on infection with West Nile virus, an encephalitic flavivirus. Cell culture studies in mouse keratinocytes and dendritic cells showed no direct antiviral effect of exogenous interferon-λ, even though expression of interferon-stimulated genes was induced. We observed no differences in West Nile virus burden between wild-type and Ifnlr1(-/-) mice in the draining lymph nodes, spleen, or blood. We detected increased West Nile virus infection in the brain and spinal cord of Ifnlr1(-/-) mice, yet this was not associated with a direct antiviral effect in mouse neurons. Instead, we observed an increase in blood-brain barrier permeability in Ifnlr1(-/-) mice. Treatment of mice with pegylated interferon-λ2 resulted in decreased blood-brain barrier permeability, reduced West Nile virus infection in the brain without affecting viremia, and improved survival against lethal virus challenge. An in vitro model of the blood-brain barrier showed that interferon-λ signaling in mouse brain microvascular endothelial cells increased transendothelial electrical resistance, decreased virus movement across the barrier, and modulated tight junction protein localization in a protein synthesis- and signal transducer and activator of transcription 1 (STAT1)-independent manner. Our data establish an indirect antiviral function of interferon-λ in which noncanonical signaling through IFNLR1 tightens the blood-brain barrier and restricts viral neuroinvasion and pathogenesis. Copyright © 2015, American Association for the Advancement of Science.

Inhibitory effect of essential oils obtained from plants grown in Colombia on yellow fever virus replication in vitro.

PubMed

Meneses, Rocío; Ocazionez, Raquel E; Martínez, Jairo R; Stashenko, Elena E

2009-03-06

An antiviral drug is needed for the treatment of patients suffering from yellow fever. Several compounds present in plants can inactive in vitro a wide spectrum of animal viruses. In the present study the inhibitory effect of essential oils of Lippia alba, Lippia origanoides, Oreganum vulgare and Artemisia vulgaris on yellow fever virus (YFV) replication was investigated. The cytotoxicity (CC(50)) on Vero cells was evaluated by the MTT reduction method. The minimum concentration of the essential oil that inhibited virus titer by more than 50% (MIC) was determined by virus yield reduction assay. YFV was incubated 24 h at 4 degrees C with essential oil before adsorption on Vero cell, and viral replication was carried out in the absence or presence of essential oil. Vero cells were exposed to essential oil 24 h at 37 degrees C before the adsorption of untreated-virus. The CC(50) values were less than 100 microg/mL and the MIC values were 3.7 and 11.1 microg/mL. The CC(50)/MIC ratio was of 22.9, 26.4, 26.5 and 8.8 for L. alba, L origanoides, O. vulgare and A. vulgaris, respectively. The presence of essential oil in the culture medium enhances the antiviral effect: L. origanoides oil at 11.1 microg/mL produced a 100% reduction of virus yield, and the same result was observed with L. alba, O. vulgare and A. vulgaris oils at 100 microg/mL. No reduction of virus yield was observed when Vero cells were treated with essential oil before the adsorption of untreated-virus. The essential oils evaluated in the study showed antiviral activities against YFV. The mode of action seems to be direct virus inactivation.

Dengue antiviral activity of polar extract from Melochia umbellata (Houtt) Stapf var. Visenia

NASA Astrophysics Data System (ADS)

Hariani Soekamto, Nunuk; Liong, S.; Fauziah, S.; Wahid, I.; Firdaus; Taba, P.; Ahmad, F.

2018-03-01

A research on the dengue antiviral activity test on the polar bark extract of M. umbelatta (Houtt.) Stapf var. Vicenia have been done to determine the relation to its activity againts brine shrimp Artemia salina. The bark was extracted by maceration with n-hexane, chloroform, and ethylacetate. The activity of the ethyl acetate extract was then tested against A. salina and dengue virus. It was found that the ethyl acetate extract was active to A. salina with the LC50 value of 101.66 μg/mL and also very active to dengue virus with the IC50 value of 1.67μg/mL. It is clear that the toxicity to brine shrimp A. salina has a positive correlation with the dengue anti virus.

Potent virucidal effect of pheophorbide a and pyropheophorbide a on enveloped viruses.

PubMed

Bouslama, Lamjed; Hayashi, Kyoko; Lee, Jung-Bum; Ghorbel, Abdelwahed; Hayashi, Toshimitsu

2011-01-01

In this study, we evaluated the inhibitory effect of ethanol and aqueous extracts from a stem of Opuntia ficus indica on replication of three kinds of viruses: two enveloped viruses [herpes simplex virus type 2 (HSV-2), influenza A virus (IFV-A)], and one non-enveloped virus [poliovirus type 1 (PV-1)]. Only ethanol extract from the cactus stem showed significant antiviral activity in vitro. Two chlorophyll derivatives, pheophorbide a and pyropheophorbide a, were isolated as active substances exhibiting potent virucidal effects on HSV-2 and IFV-A, but no activity against PV-1 was observed. These findings suggest that these active compounds might recognize specific glycoproteins of enveloped viruses, precluding their binding to host cell receptors and inhibiting viral infections.

Ubiquitin-like modifier FAT10 attenuates RIG-I mediated antiviral signaling by segregating activated RIG-I from its signaling platform

PubMed Central

Nguyen, Nhung T.H.; Now, Hesung; Kim, Woo-Jong; Kim, Nari; Yoo, Joo-Yeon

2016-01-01

RIG-I is a key cytosolic RNA sensor that mediates innate immune defense against RNA virus. Aberrant RIG-I activity leads to severe pathological states such as autosomal dominant multi-system disorder, inflammatory myophathies and dermatomyositis. Therefore, identification of regulators that ensure efficient defense without harmful immune-pathology is particularly critical to deal with RIG-I-associated diseases. Here, we presented the inflammatory inducible FAT10 as a novel negative regulator of RIG-I-mediated inflammatory response. In various cell lines, FAT10 protein is undetectable unless it is induced by pro-inflammatory cytokines. FAT10 non-covalently associated with the 2CARD domain of RIG-I, and inhibited viral RNA-induced IRF3 and NF-kB activation through modulating the RIG-I protein solubility. We further demonstrated that FAT10 was recruited to RIG-I-TRIM25 to form an inhibitory complex where FAT10 was stabilized by E3 ligase TRIM25. As the result, FAT10 inhibited the antiviral stress granules formation contains RIG-I and sequestered the active RIG-I away from the mitochondria. Our study presented a novel mechanism to dampen RIG-I activity. Highly accumulated FAT10 is observed in various cancers with pro-inflammatory environment, therefore, our finding which uncovered the suppressive effect of the accumulated FAT10 during virus-mediated inflammatory response may also provide molecular clue to understand the carcinogenesis related with infection and inflammation. PMID:26996158

Ubiquitin-like modifier FAT10 attenuates RIG-I mediated antiviral signaling by segregating activated RIG-I from its signaling platform.

PubMed

Nguyen, Nhung T H; Now, Hesung; Kim, Woo-Jong; Kim, Nari; Yoo, Joo-Yeon

2016-03-21

RIG-I is a key cytosolic RNA sensor that mediates innate immune defense against RNA virus. Aberrant RIG-I activity leads to severe pathological states such as autosomal dominant multi-system disorder, inflammatory myophathies and dermatomyositis. Therefore, identification of regulators that ensure efficient defense without harmful immune-pathology is particularly critical to deal with RIG-I-associated diseases. Here, we presented the inflammatory inducible FAT10 as a novel negative regulator of RIG-I-mediated inflammatory response. In various cell lines, FAT10 protein is undetectable unless it is induced by pro-inflammatory cytokines. FAT10 non-covalently associated with the 2CARD domain of RIG-I, and inhibited viral RNA-induced IRF3 and NF-kB activation through modulating the RIG-I protein solubility. We further demonstrated that FAT10 was recruited to RIG-I-TRIM25 to form an inhibitory complex where FAT10 was stabilized by E3 ligase TRIM25. As the result, FAT10 inhibited the antiviral stress granules formation contains RIG-I and sequestered the active RIG-I away from the mitochondria. Our study presented a novel mechanism to dampen RIG-I activity. Highly accumulated FAT10 is observed in various cancers with pro-inflammatory environment, therefore, our finding which uncovered the suppressive effect of the accumulated FAT10 during virus-mediated inflammatory response may also provide molecular clue to understand the carcinogenesis related with infection and inflammation.

Structural optimization of N1-aryl-benzimidazoles for the discovery of new non-nucleoside reverse transcriptase inhibitors active against wild-type and mutant HIV-1 strains.

PubMed

Monforte, Anna Maria; De Luca, Laura; Buemi, Maria Rosa; Agharbaoui, Fatima E; Pannecouque, Christophe; Ferro, Stefania

2018-02-01

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are recommended components of preferred combination antiretroviral therapies used for the treatment of human immunodeficiency virus (HIV) infection. These regimens are extremely effective in suppressing virus replication. Recently, our research group identified some N 1 -aryl-2-arylthioacetamido-benzimidazoles as a novel class of NNRTIs. In this research work we report the design, the synthesis and the structure-activity relationship studies of new compounds (20-34) in which some structural modifications have been introduced in order to investigate their effects on reverse transcriptase (RT) inhibition and to better define the features needed to increase the antiviral activity. Most of the new compounds proved to be highly effective in inhibiting both RT enzyme at nanomolar concentrations and HIV-1 replication in MT4 cells with minimal cytotoxicity. Among them, the most promising N 1 -aryl-2-arylthioacetamido-benzimidazoles and N 1 -aryl-2-aryloxyacetamido-benzimidazoles were also tested toward a panel of single- and double-mutants strain responsible for resistance to NNRTIs, showing in vitro antiviral activity toward single mutants L100I, K103N, Y181C, Y188L and E138K. The best results were observed for derivatives 29 and 33 active also against the double mutants F227L and V106A. Computational approaches were applied in order to rationalize the potency of the new synthesized inhibitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antibacterial and antiviral roles of a fish β-defensin expressed both in pituitary and testis.

PubMed

Jin, Jun-Yan; Zhou, Li; Wang, Yang; Li, Zhi; Zhao, Jiu-Gang; Zhang, Qi-Ya; Gui, Jian-Fang

2010-12-20

Defensins are a group of cationic peptides that exhibit broad-spectrum antimicrobial activity. In this study, we cloned and characterized a β-defensin from pituitary cDNA library of a protogynous hermaphroditic orange-spotted grouper (Epinephelus coioides). Interestingly, the β-defensin was shown to be dominantly expressed in pituitary and testis by RT-PCR and Western blot analysis, and its transcript level is significantly upregulated in reproduction organs from intersexual gonad to testis during the natural and artificial sex reversal. Promoter sequence and the responsible activity region analyses revealed the pituitary-specific POU1F1a transcription binding site and testis-specific SRY responsible site, and demonstrated that the pituitary-specific POU1F1a transcription binding site that locates between -180 and -208 bp is the major responsible region of grouper β-defensin promoter activity. Immunofluorescence localization observed its pituicyte expression in pituitary and spermatogonic cell expression in testis. Moreover, both in vitro antibacterial activity assay of the recombinant β-defensin and in vivo embryo microinjection of the β-defensin mRNA were shown to be effective in killing gram-negative bacteria. And, its antiviral role was also demonstrated in EPC cells transfected with the β-defensin construct. Additionally, the antibacterial activity was sensitive to concentrations of Na(+), K(+), Ca(2+) and Mg(2+). The above intriguing findings strongly suggest that the fish β-defensin might play significant roles in both innate immunity defense and reproduction endocrine regulation.

Innate Sensing of Influenza A Virus Hemagglutinin Glycoproteins by the Host Endoplasmic Reticulum (ER) Stress Pathway Triggers a Potent Antiviral Response via ER-Associated Protein Degradation.

PubMed

Frabutt, Dylan A; Wang, Bin; Riaz, Sana; Schwartz, Richard C; Zheng, Yong-Hui

2018-01-01

Innate immunity provides an immediate defense against infection after host cells sense danger signals from microbes. Endoplasmic reticulum (ER) stress arises from accumulation of misfolded/unfolded proteins when protein load overwhelms the ER folding capacity, which activates the unfolded protein response (UPR) to restore ER homeostasis. Here, we show that a mechanism for antiviral innate immunity is triggered after the ER stress pathway senses viral glycoproteins. When hemagglutinin (HA) glycoproteins from influenza A virus (IAV) are expressed in cells, ER stress is induced, resulting in rapid HA degradation via proteasomes. The ER-associated protein degradation (ERAD) pathway, an important UPR function for destruction of aberrant proteins, mediates HA degradation. Three class I α-mannosidases were identified to play a critical role in the degradation process, including EDEM1, EDEM2, and ERManI. HA degradation requires either ERManI enzymatic activity or EDEM1/EDEM2 enzymatic activity when ERManI is not expressed, indicating that demannosylation is a critical step for HA degradation. Silencing of EDEM1, EDEM2, and ERManI strongly increases HA expression and promotes IAV replication. Thus, the ER stress pathway senses influenza HA as "nonself" or misfolded protein and sorts HA to ERAD for degradation, resulting in inhibition of IAV replication. IMPORTANCE Viral nucleic acids are recognized as important inducers of innate antiviral immune responses that are sensed by multiple classes of sensors, but other inducers and sensors of viral innate immunity need to be identified and characterized. Here, we used IAV to investigate how host innate immunity is activated. We found that IAV HA glycoproteins induce ER stress, resulting in HA degradation via ERAD and consequent inhibition of IAV replication. In addition, we have identified three class I α-mannosidases, EDEM1, EDEM2, and ERManI, which play a critical role in initiating HA degradation. Knockdown of these proteins substantially increases HA expression and IAV replication. The enzymatic activities and joint actions of these mannosidases are required for this antiviral activity. Our results suggest that viral glycoproteins induce a strong innate antiviral response through activating the ER stress pathway during viral infection. Copyright © 2017 American Society for Microbiology.

Antiviral activity of A771726, the active metabolite of leflunomide, against Junín virus.

PubMed

Sepúlveda, Claudia S; García, Cybele C; Damonte, Elsa B

2018-05-01

The aim of this study was to investigate the effect of A771726, the active metabolite of leflunomide, (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad against the infection with Junín virus (JUNV), agent of Argentine hemorrhagic fever (AHF). The treatment with non-cytotoxic concentrations of A771726 of Vero and A549 cells infected with JUNV inhibited virus replication in a dose-dependent manner, as determined by virus yield reduction assay. The antiviral effectiveness of A771726 was not importantly affected by the multiplicity of infection and the virus strain. Moreover, the combination of A771726 and ribavirin had a significantly more potent antiviral activity than each single drug treatment. Mechanistic studies showed that the main action of A771726 is exerted before 6 h of JUNV infection. Accordingly, inhibition of viral RNA synthesis was detected in treated infected cells by real time RT-PCR. The exogenous addition of uridine or orotic acid produced a partial reversal of the inhibitory effect of A771726 on infective virus production whereas a total reversion was detected on JUNV RNA synthesis, probably by restoration of the enzymatic activity of dihydroorotate dehydrogenase (DHODH) and the intracellular pyrimidine pools. In conclusion, these results suggest that the antiviral target would be viral RNA synthesis through pyrimidine depletion, but any other effect of the compound on JUNV infection cannot be excluded. This study opens the possibility of the therapeutic application of a wide spectrum host-targeted compound alone or in combination with ribavirin to combat AHF as well as other human pathogenic arenaviruses. © 2018 Wiley Periodicals, Inc.

Antiviral cationic peptides as a strategy for innovation in global health therapeutics for dengue virus: high yield production of the biologically active recombinant plectasin peptide.

PubMed

Rothan, Hussin A; Mohamed, Zulqarnain; Suhaeb, Abdulrazzaq M; Rahman, Noorsaadah Abd; Yusof, Rohana

2013-11-01

Dengue virus infects millions of people worldwide, and there is no vaccine or anti-dengue therapeutic available. Antimicrobial peptides have been shown to possess effective antiviral activity against various viruses. One of the main limitations of developing these peptides as potent antiviral drugs is the high cost of production. In this study, high yield production of biologically active plectasin peptide was inexpensively achieved by producing tandem plectasin peptides as inclusion bodies in E. coli. Antiviral activity of the recombinant peptide towards dengue serotype-2 NS2B-NS3 protease (DENV2 NS2B-NS3pro) was assessed as a target to inhibit dengue virus replication in Vero cells. Single units of recombinant plectasin were collected after applying consecutive steps of refolding, cleaving by Factor Xa, and nickel column purification to obtain recombinant proteins of high purity. The maximal nontoxic dose (MNTD) of the recombinant peptide against Vero cells was 20 μM (100 μg/mL). The reaction velocity of DENV2 NS2B-NS3pro decreased significantly after increasing concentrations of recombinant plectasin were applied to the reaction mixture. Plectasin peptide noncompetitively inhibited DENV2 NS2B-NS3pro at Ki value of 5.03 ± 0.98 μM. The percentage of viral inhibition was more than 80% at the MNTD value of plectasin. In this study, biologically active recombinant plectasin which was able to inhibit dengue protease and viral replication in Vero cells was successfully produced in E. coli in a time- and cost- effective method. These findings are potentially important in the development of potent therapeutics against dengue infection.

Antiviral Cationic Peptides as a Strategy for Innovation in Global Health Therapeutics for Dengue Virus: High Yield Production of the Biologically Active Recombinant Plectasin Peptide

PubMed Central

Mohamed, Zulqarnain; Suhaeb, Abdulrazzaq M.; Rahman, Noorsaadah Abd; Yusof, Rohana

2013-01-01

Abstract Dengue virus infects millions of people worldwide, and there is no vaccine or anti-dengue therapeutic available. Antimicrobial peptides have been shown to possess effective antiviral activity against various viruses. One of the main limitations of developing these peptides as potent antiviral drugs is the high cost of production. In this study, high yield production of biologically active plectasin peptide was inexpensively achieved by producing tandem plectasin peptides as inclusion bodies in E. coli. Antiviral activity of the recombinant peptide towards dengue serotype-2 NS2B-NS3 protease (DENV2 NS2B-NS3pro) was assessed as a target to inhibit dengue virus replication in Vero cells. Single units of recombinant plectasin were collected after applying consecutive steps of refolding, cleaving by Factor Xa, and nickel column purification to obtain recombinant proteins of high purity. The maximal nontoxic dose (MNTD) of the recombinant peptide against Vero cells was 20 μM (100 μg/mL). The reaction velocity of DENV2 NS2B-NS3pro decreased significantly after increasing concentrations of recombinant plectasin were applied to the reaction mixture. Plectasin peptide noncompetitively inhibited DENV2 NS2B-NS3pro at Ki value of 5.03±0.98 μM. The percentage of viral inhibition was more than 80% at the MNTD value of plectasin. In this study, biologically active recombinant plectasin which was able to inhibit dengue protease and viral replication in Vero cells was successfully produced in E. coli in a time- and cost- effective method. These findings are potentially important in the development of potent therapeutics against dengue infection. PMID:24044366

Aurantiamide acetate from baphicacanthus cusia root exhibits anti-inflammatory and anti-viral effects via inhibition of the NF-κB signaling pathway in Influenza A virus-infected cells.

PubMed

Zhou, Beixian; Yang, Zifeng; Feng, Qitong; Liang, Xiaoli; Li, Jing; Zanin, Mark; Jiang, Zhihong; Zhong, Nanshan

2017-03-06

Baphicacanthus cusia root also names "Nan Ban Lan Gen" has been traditionally used to prevent and treat influenza A virus infections. Here, we identified a peptide derivative, aurantiamide acetate (compound E17), as an active compound in extracts of B. cusia root. Although studies have shown that aurantiamide acetate possesses antioxidant and anti-inflammatory properties, the effects and mechanism by which it functions as an anti-viral or as an anti-inflammatory during influenza virus infection are poorly defined. Here we investigated the anti-viral activity and possible mechanism of compound E17 against influenza virus infection. The anti-viral activity of compound E17 against Influenza A virus (IAV) was determined using the cytopathic effect (CPE) inhibition assay. Viruses were titrated on Madin-Darby canine kidney (MDCK) cells by plaque assays. Ribonucleoprotein (RNP) luciferase reporter assay was further conducted to investigate the effect of compound E17 on the activity of the viral polymerase complex. HEK293T cells with a stably transfected NF-κB luciferase reporter plasmid were employed to examine the activity of compound E17 on NF-κB activation. Activation of the host signaling pathway induced by IAV infection in the absence or presence of compound E17 was assessed by western blotting. The effect of compound E17 on IAV-induced expression of pro-inflammatory cytokines was measured by real-time quantitative PCR and Luminex assays. Compound E17 exerted an inhibitory effect on IAV replication in MDCK cells but had no effect on avian IAV and influenza B virus. Treatment with compound E17 resulted in a reduction of RNP activity and virus titers. Compound E17 treatment inhibited the transcriptional activity of NF-κB in a NF-κB luciferase reporter stable HEK293 cell after stimulation with TNF-α. Furthermore, compound E17 blocked the activation of the NF-κB signaling pathway and decreased mRNA expression levels of pro-inflammatory genes in infected cells. Compound E17 also suppressed the production of IL-6, TNF-α, IL-8, IP-10 and RANTES from IAV-infected lung epithelial (A549) cells. These results indicate that compound E17 isolated from B. cusia root has potent anti-viral and anti-inflammatory effects on IAV-infected cells via inhibition of the NF-κB pathway. Therefore, compound E17 could be a potential therapeutic agent for the treatment of influenza. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Limonoids from Melia azedarach Fruits as Inhibitors of Flaviviruses and Mycobacterium tubercolosis.

PubMed

Sanna, Giuseppina; Madeddu, Silvia; Giliberti, Gabriele; Ntalli, Nikoletta G; Cottiglia, Filippo; De Logu, Alessandro; Agus, Emanuela; Caboni, Pierluigi

2015-01-01

The biological diversity of nature is the source of a wide range of bioactive molecules. The natural products, either as pure compounds or as standardized plant extracts, have been a successful source of inspiration for the development of new drugs. The present work was carried out to investigate the cytotoxicity, antiviral and antimycobacterial activity of the methanol extract and of four identified limonoids from the fruits of Melia azedarach (Meliaceae). The extract and purified limonoids were tested in cell-based assays for antiviral activity against representatives of ssRNA, dsRNA and dsDNA viruses and against Mycobacterium tuberculosis. Very interestingly, 3-α-tigloyl-melianol and melianone showed a potent antiviral activity (EC50 in the range of 3-11μM) against three important human pathogens, belonging to Flaviviridae family, West Nile virus, Dengue virus and Yellow Fever virus. Mode of action studies demonstrated that title compounds were inhibitors of West Nile virus only when added during the infection, acting as inhibitors of the entry or of a very early event of life cycle. Furthermore, 3-α-tigloyl-melianol and methyl kulonate showed interesting antimycobacterial activity (with MIC values of 29 and 70 μM respectively). The limonoids are typically lipophilic compounds present in the fruits of Melia azeradach. They are known as cytotoxic compounds against different cancer cell lines, while their potential as antiviral and antibacterial was poorly investigated. Our studies show that they may serve as a good starting point for the development of novel drugs for the treatment of infections by Flaviviruses and Mycobacterium tuberculosis, for which there is a continued need.

Digestion of chrysanthemum stunt viroid by leaf extracts of Capsicum chinense indicates strong RNA-digesting activity.

PubMed

Iraklis, Boubourakas; Kanda, Hiroko; Nabeshima, Tomoyuki; Onda, Mayu; Ota, Nao; Koeda, Sota; Hosokawa, Munetaka

2016-08-01

CSVd could not infect Nicotiana benthamiana when the plants were pretreated with crude leaf extract of Capsicum chinense 'Sy-2'. C. chinense leaves were revealed to contain strong RNA-digesting activity. Several studies have identified active antiviral and antiviroid agents in plants. Capsicum plants are known to contain antiviral agents, but the mechanism of their activity has not been determined. We aimed to elucidate the mechanism of Capsicum extract's antiviroid activity. Chrysanthemum stunt viroid (CSVd) was inoculated into Nicotiana benthamiana plants before or after treating the plants with a leaf extract of Capsicum chinense 'Sy-2'. CSVd infection was determined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) 3 weeks after inoculation. When Capsicum extract was sprayed or painted onto N. benthamiana before inoculation, it was effective in preventing infection by CSVd. To evaluate CSVd digestion activity in leaf extracts, CSVd was mixed with leaf extracts of Mirabilis, Phytolacca, Pelargonium and Capsicum. CSVd-digesting activities were examined by quantifying undigested CSVd using qRT-PCR, and RNA gel blotting permitted visualization of the digested CSVd. Only Capsicum leaf extract digested CSVd, and in the Capsicum treatment, small digested CSVd products were detected by RNA gel blot analysis. When the digesting experiment was performed for various cultivars and species of Capsicum, only cultivars of C. chinense showed strong CSVd-digesting activity. Our observations indicated that Capsicum extract contains strong RNA-digesting activity, leading to the conclusion that this activity is the main mechanism for protection from infection by CSVd through spraying or painting before inoculation. To our knowledge, this is the first report of a strong RNA-digesting activity by a plant extract.

Inhibition of herpes simplex virus type 1 entry by chloride channel inhibitors tamoxifen and NPPB

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

Zheng, Kai; College of Life Science and Technology, Jinan University, Guangzhou; Chen, Maoyun

2014-04-18

Highlights: • We analyze the anti-HSV potential of chloride channel inhibitors. • Tamoxifen and NPPB show anti-HSV-1 and anti-ACV-resistant HSV-1 activities. • HSV-1 infection induces intracellular chloride concentration increasing. • Tamoxifen and NPPB inhibit HSV-1 early infection. • Tamoxifen and NPPB prevent the fusion process of HSV-1. - Abstract: Herpes simplex virus type 1 (HSV-1) infection is very common worldwide and can cause significant health problems from periodic skin and corneal lesions to encephalitis. Appearance of drug-resistant viruses in clinical therapy has made exploring novel antiviral agents emergent. Here we show that chloride channel inhibitors, including tamoxifen and 5-nitro-2-(3-phenyl-propylamino) benzoicmore » acid (NPPB), exhibited extensive antiviral activities toward HSV-1 and ACV-resistant HSV viruses. HSV-1 infection induced chloride ion influx while treatment with inhibitors reduced the increase of intracellular chloride ion concentration. Pretreatment or treatment of inhibitors at different time points during HSV-1 infection all suppressed viral RNA synthesis, protein expression and virus production. More detailed studies demonstrated that tamoxifen and NPPB acted as potent inhibitors of HSV-1 early entry step by preventing viral binding, penetration and nuclear translocation. Specifically the compounds appeared to affect viral fusion process by inhibiting virus binding to lipid rafts and interrupting calcium homeostasis. Taken together, the observation that tamoxifen and NPPB can block viral entry suggests a stronger potential for these compounds as well as other ion channel inhibitors in antiviral therapy against HSV-1, especially the compound tamoxifen is an immediately actionable drug that can be reused for treatment of HSV-1 infections.« less

Activities of the human immunodeficiency virus type 1 (HIV-1) protease inhibitor nelfinavir mesylate in combination with reverse transcriptase and protease inhibitors against acute HIV-1 infection in vitro.

PubMed

Patick, A K; Boritzki, T J; Bloom, L A

1997-10-01

Nelfinavir mesylate (formerly AG1343) is a potent and selective, nonpeptidic inhibitor of human immunodeficiency virus type 1 (HIV-1) protease that was discovered by protein structure-based design methodologies. We evaluated the antiviral and cytotoxic effects of two-drug combinations of nelfinavir with the clinically approved antiretroviral therapeutics zidovudine (ZDV), lamivudine (3TC), dideoxycytidine (ddC; zalcitabine), stavudine (d4T), didanosine (ddI), indinavir, saquinavir, and ritonavir and a three-drug combination of nelfinavir with ZDV and 3TC against an acute HIV-1 strain RF infection of CEM-SS cells in vitro. Quantitative assessment of drug interaction was evaluated by a universal response surface approach (W. R. Greco, G. Bravo, and J. C. Parsons, Pharm. Rev. 47:331-385, 1995) and by the method of M. N. Prichard and C. Shipman (Antiviral Res. 14:181-206, 1990). Both analytical methods yielded similar results and showed that the two-drug combinations of nelfinavir with the reverse transcriptase inhibitors ZDV, 3TC, ddI, d4T, and ddC and the three-drug combination with ZDV and 3TC resulted in additive to statistically significant synergistic interactions. In a similar manner, the combination of nelfinavir with the three protease inhibitors resulted in additive (ritonavir and saquinavir) to slightly antagonistic (indinavir) interactions. In all combinations, minimal cellular cytotoxicity was observed with any drug alone and in combination. These results suggest that administration of combinations of the appropriate doses of nelfinavir with other currently approved antiretroviral therapeutic agents in vivo may result in enhanced antiviral activity with no associated increase in cellular cytotoxicity.

Activities of the human immunodeficiency virus type 1 (HIV-1) protease inhibitor nelfinavir mesylate in combination with reverse transcriptase and protease inhibitors against acute HIV-1 infection in vitro.

PubMed Central

Patick, A K; Boritzki, T J; Bloom, L A

1997-01-01

Nelfinavir mesylate (formerly AG1343) is a potent and selective, nonpeptidic inhibitor of human immunodeficiency virus type 1 (HIV-1) protease that was discovered by protein structure-based design methodologies. We evaluated the antiviral and cytotoxic effects of two-drug combinations of nelfinavir with the clinically approved antiretroviral therapeutics zidovudine (ZDV), lamivudine (3TC), dideoxycytidine (ddC; zalcitabine), stavudine (d4T), didanosine (ddI), indinavir, saquinavir, and ritonavir and a three-drug combination of nelfinavir with ZDV and 3TC against an acute HIV-1 strain RF infection of CEM-SS cells in vitro. Quantitative assessment of drug interaction was evaluated by a universal response surface approach (W. R. Greco, G. Bravo, and J. C. Parsons, Pharm. Rev. 47:331-385, 1995) and by the method of M. N. Prichard and C. Shipman (Antiviral Res. 14:181-206, 1990). Both analytical methods yielded similar results and showed that the two-drug combinations of nelfinavir with the reverse transcriptase inhibitors ZDV, 3TC, ddI, d4T, and ddC and the three-drug combination with ZDV and 3TC resulted in additive to statistically significant synergistic interactions. In a similar manner, the combination of nelfinavir with the three protease inhibitors resulted in additive (ritonavir and saquinavir) to slightly antagonistic (indinavir) interactions. In all combinations, minimal cellular cytotoxicity was observed with any drug alone and in combination. These results suggest that administration of combinations of the appropriate doses of nelfinavir with other currently approved antiretroviral therapeutic agents in vivo may result in enhanced antiviral activity with no associated increase in cellular cytotoxicity. PMID:9333041

UPLC-PDA-ESI-qTOF-MS profiling and potent anti-HSV-II activity of Eucalyptus sideroxylon leaves.

PubMed

Okba, Mona M; El Gedaily, Rania A; Ashour, Rehab M

2017-11-15

Eucalyptus is one of the most important and highly exploited genus in family Myrtaceae. An UPLC/PDA/ESI-qTOF-MS method was adopted to identify Eucalyptus sideroxylon Cunn. ex Woolls leaves phytoconstituents. Cytotoxicity of E. sideroxylon leaves phloroglucinol-rich extract (PGRE) on VERO cells was determined. The antiviral effect of PGRE against hepatitis A (HAV), herpes simplex type 1 (HSV-I), herpes simplex type 2 (HSV-II), coxsackie (CoxB4), and adenoviruses was in vitro evaluated using MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide). UPLC-MS analysis allowed the identification of 70 metabolites including: 26 triterpenes, 13 phloroglucinols, 8 fatty acids, 5 flavonoids, 5 oleuropeic acid glucosides, 3 gallic acid derivatives, and 10 miscellaneous. Twenty four metabolites identified in the leaves of E. sideroxylon and four in the genus Eucalyptus are reported herein for the first time. PGRE was found to be non-cytotoxic; the concentration that reduced the cell viability by 50% (CC 50 ) was 0.808mg/mL. Maximum non-toxic concentration (MNTC) of PGRE on Vero cells was 0.312mg/mL. The best antiviral activity was observed against HSV-II. Its mechanism was through decreasing the viral replication (IC 50 189.36μg/mL, 87.65% inhibition) and attachment on Vero cells (IC 50 199.34μg/mL, 83.13% inhibition) rather than virucidal effect (IC 50 293.1μg/mL, 50.68% inhibition). This study provides a complete map for E. sideroxylon leaves composition. It also suggests the plant as a source of new antiviral agents. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro anti-viral effect of β-santalol against influenza viral replication.

PubMed

Paulpandi, Manickam; Kannan, Soundarapandian; Thangam, Ramar; Kaveri, Krishnasamy; Gunasekaran, Palani; Rejeeth, Chandrababu

2012-02-15

The anti-influenza A/HK (H3N2) virus activity of β-santalol was evaluated in MDCK cells and investigated the effect of β-santalol on synthesis of viral mRNAs. β-Santalol was investigated for its antiviral activity against influenza A/HK (H3N2) virus using a cytopathic effect (CPE) reduction method. β-Santalol exhibited anti-influenza A/HK (H3N2) virus activity of 86% with no cytotoxicity at the concentration of 100 μg/ml reducing the formation of a visible CPE. Oseltamivir also showed moderate antiviral activity of about 83% against influenza A/HK (H3N2) virus at the concentration of 100 μg/ml. Furthermore, the mechanism of anti-influenza virus action in the inhibition of viral mRNA synthesis was analyzed by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), and the data indicated an inhibitory effect in late viral RNA synthesis compared with oseltamivir in the presence of 100 μg/ml of β-santalol. β-Santalol should be further studied for therapeutic and prophylactic potential especially for influenza epidemics and pandemics. Copyright © 2011 Elsevier GmbH. All rights reserved.

Synthesis and Biological Evaluation of Analogues of AKT (Protein Kinase B) Inhibitor-IV

PubMed Central

Sun, Qi; Wu, Runzhi; Cai, Sutang; Lin, Yuan; Sellers, Llewlyn; Sakamoto, Kaori; He, Biao; Peterson, Blake R.

2011-01-01

Inhibitors of the PI3-kinase/AKT (protein kinase B) pathway are under investigation as anticancer and antiviral agents. The benzimidazole derivative AKT inhibitor-IV (ChemBridge 5233705) affects this pathway and exhibits potent anticancer and antiviral activity. To probe its biological activity, we synthesized AKT inhibitor-IV and 21 analogues using a novel six-step route based on ZrCl4-catalyzed cyclization of 1,2-arylenediamines with α,β-unsaturated aldehydes. We examined effects on viability of HeLa carcinoma cells, viability of normal human cells (NHBE), replication of recombinant parainfluenza virus 5 (PIV5) in HeLa cells, and replication of the intracellular bacterium Mycobacterium fortuitum in HeLa cells. Replacement of the benzimidazole N-ethyl substitutent of AKT inhibitor-IV with N-hexyl and N-dodecyl groups enhanced antiviral activity and cytotoxicity against the cancer cell line, but these compounds showed substantially lower toxicity (from 6-fold to >20-fold) against NHBE cells, and no effect on M. fortuitum, suggesting inhibition of one or more host protein(s) required for proliferation of cancer cells and PIV5. The key structural elements identified here may facilitate identification of targets of this highly biologically active scaffold. PMID:21319800

The chicken 2'-5' oligoadenylate synthetase A inhibits the replication of West Nile virus.

PubMed

Tag-El-Din-Hassan, Hassan T; Sasaki, Nobuya; Moritoh, Kanako; Torigoe, Daisuke; Maeda, Akihiko; Agui, Takashi

2012-08-01

West Nile virus (WNV) is a pathogen to cause West Nile encephalitis when the infection occurs in the brain. Previous studies in mice identified the 2'-5' oligoadenylate synthetase 1b (Oas1b) gene as a determining factor for resistance to WNV infection. In addition, it has been suggested that human OAS1 and OASL are associated with the resistance to the WNV infection. WNV is maintained in nature through a complex life cycle involving wildbirds and mosquitoes. Birds are not only susceptible to the WNV, but also act as reservoir hosts, thus participating in the spread of the disease. It has previously been reported that chicken OASL possesses the oligoadenylate synthetase activity. However, until now the antiviral activity of chicken OASL has not been determined. In this study, we investigated the putative antiviral activity of chicken OASL by ectopic expression of this enzyme in mammalian cells and then infecting these cells with WNV replicon. We demonstrate that chicken OASL has an antiviral activity against the WNV. This is the first report to show that chicken OASL is associated with the resistance to the WNV infection.

CRISPR-Cas Targeting of Host Genes as an Antiviral Strategy.

PubMed

Chen, Shuliang; Yu, Xiao; Guo, Deyin

2018-01-16

Currently, a new gene editing tool-the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) associated (Cas) system-is becoming a promising approach for genetic manipulation at the genomic level. This simple method, originating from the adaptive immune defense system in prokaryotes, has been developed and applied to antiviral research in humans. Based on the characteristics of virus-host interactions and the basic rules of nucleic acid cleavage or gene activation of the CRISPR-Cas system, it can be used to target both the virus genome and host factors to clear viral reservoirs and prohibit virus infection or replication. Here, we summarize recent progress of the CRISPR-Cas technology in editing host genes as an antiviral strategy.

Isohelical DNA-Binding Oligomers: Antiviral Activity and Application for the Design of Nanostructured Devices

NASA Astrophysics Data System (ADS)

Gursky, Georgy; Nikitin, Alexei; Surovaya, Anna; Grokhovsky, Sergey; Andronova, Valeria; Galegov, Georgy

We performed a systematic search for new structural motifs isohelical to double-stranded DNA and found five motifs that can be used for the design and synthesis of new DNA-binding oligomers. Some of the DNA-binding oligomers can be equipped with fluorescence chromophores and metal-chelating groups and may serve as conductive wires in nano-scaled electric circuits. A series of new DNA-binding ligands were synthesized by a modular assembly of pyrrole carboxamides and novel pseudopeptides of the form (XY)n. Here, Y is a glycine residue; n is the degree of polymerization. X is an unusual amino acid residue containing a five-membered aromatic ring. Antiviral activity of bis-linked netropsin derivatives is studied. Bis-netropsins containing 15 and 31 lysine residues at the N-termini inhibit most effectively reproduction of the herpes virus type 1 in the Vero cell culture, including virus variants resistant to acyclovir and its analogues. Antiviral activity of bis-linked netropsin derivatives is correlated with their ability to interact with long clusters of AT-base pairs in the origin of replication of the viral DNA.

Alphavirus-based DNA vaccine breaks immunological tolerance by activating innate antiviral pathways

PubMed Central

Leitner, Wolfgang W.; Hwang, Leroy N.; Deveer, Michael J.; Zhou, Aimin; Silverman, Robert H.; Williams, Bryan R.G.; Dubensky, Thomas W.; Ying, Han; Restifo, Nicholas P.

2006-01-01

Cancer vaccines targeting ‘self’ antigens that are expressed at consistently high levels by tumor cells are potentially useful in immunotherapy, but immunological tolerance may block their function. Here, we describe a novel, naked DNA vaccine encoding an alphavirus replicon (self-replicating mRNA) and the self/tumor antigen tyrosinase-related protein-1. Unlike conventional DNA vaccines, this vaccine can break tolerance and provide immunity to melanoma. The vaccine mediates production of double-stranded RNA, as evidenced by the autophosphorylation of protein kinase R. Double-stranded RNA is critical to vaccine function because both the immunogenicity and the anti-tumor activity of the vaccine are blocked in mice deficient for the RNase L enzyme, a key component of the 2′,5′-linked oligoadenylate synthetase antiviral pathway involved in double-stranded RNA recognition. This study shows for the first time that alphaviral replicon-encoding DNA vaccines activate innate immune pathways known to drive antiviral immune responses, and points the way to strategies for improving the efficacy of immunization with naked DNA. PMID:12496961

Sensing of Immature Particles Produced by Dengue Virus Infected Cells Induces an Antiviral Response by Plasmacytoid Dendritic Cells

PubMed Central

Hillaire, Marine L. B.; Dejnirattisai, Wanwisa; Mongkolsapaya, Juthathip; Screaton, Gavin R.; Davidson, Andrew D.; Dreux, Marlène

2014-01-01

Dengue virus (DENV) is the leading cause of mosquito-borne viral illness and death in humans. Like many viruses, DENV has evolved potent mechanisms that abolish the antiviral response within infected cells. Nevertheless, several in vivo studies have demonstrated a key role of the innate immune response in controlling DENV infection and disease progression. Here, we report that sensing of DENV infected cells by plasmacytoid dendritic cells (pDCs) triggers a robust TLR7-dependent production of IFNα, concomitant with additional antiviral responses, including inflammatory cytokine secretion and pDC maturation. We demonstrate that unlike the efficient cell-free transmission of viral infectivity, pDC activation depends on cell-to-cell contact, a feature observed for various cell types and primary cells infected by DENV, as well as West Nile virus, another member of the Flavivirus genus. We show that the sensing of DENV infected cells by pDCs requires viral envelope protein-dependent secretion and transmission of viral RNA. Consistently with the cell-to-cell sensing-dependent pDC activation, we found that DENV structural components are clustered at the interface between pDCs and infected cells. The actin cytoskeleton is pivotal for both this clustering at the contacts and pDC activation, suggesting that this structural network likely contributes to the transmission of viral components to the pDCs. Due to an evolutionarily conserved suboptimal cleavage of the precursor membrane protein (prM), DENV infected cells release uncleaved prM containing-immature particles, which are deficient for membrane fusion function. We demonstrate that cells releasing immature particles trigger pDC IFN response more potently than cells producing fusion-competent mature virus. Altogether, our results imply that immature particles, as a carrier to endolysosome-localized TLR7 sensor, may contribute to regulate the progression of dengue disease by eliciting a strong innate response. PMID:25340500

Evaluation of the immunomodulatory and antiviral effects of the cytokine combination IFN-α and IL-7 in the lymphocytic choriomeningitis virus and Friend retrovirus mouse infection models.

PubMed

Audigé, Annette; Hofer, Ursula; Dittmer, Ulf; van den Broek, Maries; Speck, Roberto F

2011-10-01

Existing therapies for chronic viral infections are still suboptimal or have considerable side effects, so new therapeutic strategies need to be developed. One option is to boost the host's immune response with cytokines. We have recently shown in an acute ex vivo HIV infection model that co-administration of interferon (IFN)-α and interleukin (IL)-7 allows us to combine the potent anti-HIV activity of IFN-α with the beneficial effects of IL-7 on T-cell survival and function. Here we evaluated the effect of combining IFN-α and IL-7 on viral replication in vivo in the chronic lymphocytic choriomeningitis virus (LCMV) and acute Friend retrovirus (FV) infection models. In the chronic LCMV model, cytokine treatment was started during the early replication phase (i.e., on day 7 post-infection [pi]). Under the experimental conditions used, exogenous IFN-α inhibited FV replication, but had no effect on viral replication in the LCMV model. There was no therapeutic benefit of IL-7 either alone or in combination with IFN-α in either of the two infection models. In the LCMV model, dose-dependent effects of the cytokine combination on T-cell phenotype/function were observed. It is possible that these effects would translate into antiviral activity in re-challenged mice. It is also possible that another type of IFN-α/β or induction of endogenous IFN-α/β alone or in combination with IL-7 would have antiviral activity in the LCMV model. Furthermore, we cannot exclude that some effect on viral titers would have been seen at later time points not investigated here (i.e., beyond day 34 pi). Finally, IFN-α/IL-7 may inhibit the replication of other viruses. Thus it might be worth testing these cytokines in other in vivo models of chronic viral infections.

Inhibitory effects of bee venom and its components against viruses in vitro and in vivo.

PubMed

Uddin, Md Bashir; Lee, Byeong-Hoon; Nikapitiya, Chamilani; Kim, Jae-Hoon; Kim, Tae-Hwan; Lee, Hyun-Cheol; Kim, Choul Goo; Lee, Jong-Soo; Kim, Chul-Joong

2016-12-01

Bee venom (BV) from honey bee (Apis Melifera L.) contains at least 18 pharmacologically active components including melittin (MLT), phospholipase A 2 (PLA 2 ), and apamin etc. BV is safe for human treatments dose dependently and proven to possess different healing properties including antibacterial and antiparasitidal properties. Nevertheless, antiviral properties of BV have not well investigated. Hence, we identified the potential antiviral properties of BV and its component against a broad panel of viruses. Co-incubation of non-cytotoxic amounts of BV and MLT, the main component of BV, significantly inhibited the replication of enveloped viruses such as Influenza A virus (PR8), Vesicular Stomatitis Virus (VSV), Respiratory Syncytial Virus (RSV), and Herpes Simplex Virus (HSV). Additionally, BV and MLT also inhibited the replication of non-enveloped viruses such as Enterovirus-71 (EV-71) and Coxsackie Virus (H3). Such antiviral properties were mainly explained by virucidal mechanism. Moreover, MLT protected mice which were challenged with lethal doses of pathogenic influenza A H1N1 viruses. Therefore, these results provides the evidence that BV and MLT could be a potential source as a promising antiviral agent, especially to develop as a broad spectrum antiviral agent.

A simple, rapid, and sensitive system for the evaluation of anti-viral drugs in rats

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

Li, Xiaoguang; Department of Medical Microbiology, Harbin Medical University, Harbin 150086; Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811

Highlights: Black-Right-Pointing-Pointer We established a novel, simple and rapid in vivo system for evaluation of anti-HIV-1 drugs with rats. Black-Right-Pointing-Pointer The system may be applicable for other antiviral drugs, and/or useful for initial screening in vivo. Black-Right-Pointing-Pointer In this system, TRI-1144 displayed the most potent anti-HIV-1 activity in vivo. -- Abstract: The lack of small animal models for the evaluation of anti-human immunodeficiency virus type 1 (HIV-1) agents hampers drug development. Here, we describe the establishment of a simple and rapid evaluation system in a rat model without animal infection facilities. After intraperitoneal administration of test drugs to rats, antiviralmore » activity in the sera was examined by the MAGI assay. Recently developed inhibitors for HIV-1 entry, two CXCR4 antagonists, TF14016 and FC131, and four fusion inhibitors, T-20, T-20EK, SC29EK, and TRI-1144, were evaluated using HIV-1{sub IIIB} and HIV-1{sub BaL} as representative CXCR4- and CCR5-tropic HIV-1 strains, respectively. CXCR4 antagonists were shown to only possess anti-HIV-1{sub IIIB} activity, whereas fusion inhibitors showed both anti-HIV-1{sub IIIB} and anti-HIV-1{sub BaL} activities in rat sera. These results indicate that test drugs were successfully processed into the rat sera and could be detected by the MAGI assay. In this system, TRI-1144 showed the most potent and sustained antiviral activity. Sera from animals not administered drugs showed substantial anti-HIV-1 activity, indicating that relatively high dose or activity of the test drugs might be needed. In conclusion, the novel rat system established here, 'phenotypic drug evaluation', may be applicable for the evaluation of various antiviral drugs in vivo.« less

Regulation of MDA5-MAVS Antiviral Signaling Axis by TRIM25 through TRAF6-Mediated NF-κB Activation.

PubMed

Lee, Na-Rae; Kim, Hye-In; Choi, Myung-Soo; Yi, Chae-Min; Inn, Kyung-Soo

2015-09-01

Tripartite motif protein 25 (TRIM25), mediates K63-linked polyubiquitination of Retinoic acid inducible gene I (RIG-I) that is crucial for downstream antiviral interferon signaling. Here, we demonstrate that TRIM25 is required for melanoma differentiation-associated gene 5 (MDA5) and MAVS mediated activation of NF-κB and interferon production. TRIM25 is required for the full activation of NF-κB at the downstream of MAVS, while it is not involved in IRF3 nuclear translocation. Mechanical studies showed that TRIM25 is involved in TRAF6-mediated NF-κB activation. These collectively indicate that TRIM25 plays an additional role in RIG-I/MDA5 signaling other than RIG-I ubiquitination via activation of NF-κB.

Impact of ethanolic lamiaceae extracts on herpesvirus infectivity in cell culture.

PubMed

Reichling, Jürgen; Nolkemper, Silke; Stintzing, Florian C; Schnitzler, Paul

2008-12-01

Extracts of medicinal plants are increasingly of interest as novel drugs for antimicrobial and antiviral agents, since microorganisms might develop resistance to commonly used antimicrobial or antiviral agents. Ethanolic extracts from Lamiaceae plants prunella, peppermint, rosemary and thyme were phytochemically characterised. The inhibitory activity of four 20% ethanolic plant extracts and four 80% ethanolic extracts against herpes simplex virus (HSV) strains was tested in cell culture. Rosmarinic acid, a typical compound in Lamiaceae species, was identified in the extracts except for thyme 20% ethanolic extract. In addition, some other phenolic compounds such as apigenin- and luteolin-derivatives were identified in different amounts. All extracts exhibited high and concentration-dependent levels of antiviral activity against free acyclovir-sensitive and acyclovir-resistant HSV-1 strains with 50% inhibitory concentrations of 0.05-0.82 microg/ml. Mechanistically, exposure of free virions as well as host cells to prunella and peppermint 80% ethanolic extracts at maximum non-cytotoxic concentrations prior to infection reduced plaque formation drastically. Thus, both extracts revealed a dual mode of action similar to aqueous lemon balm extracts. Since infectivity of acyclovir-susceptible and acyclovir-resistant HSV strains was significantly reduced with Lamiaceae extracts, the results obtained indicate that ethanolic plant extracts affected herpesvirus prior to and during adsorption and in a different way than acyclovir. Based on its dual mode of action, e.g. antiviral effect against free virions and blocking virus attachment to host cells, prunella and peppermint 80% ethanolic extracts are promising antiviral agents in recurrent herpes labialis for topical therapeutic applications. 2008 S. Karger AG, Basel.

Human and Mouse Eosinophils Have Antiviral Activity against Parainfluenza Virus

PubMed Central

Bivins-Smith, Elizabeth R.; Nie, Zhenying; Scott, Gregory D.; Lee, James J.; Lee, Nancy A.; Fryer, Allison D.; Jacoby, David B.

2016-01-01

Respiratory viruses cause asthma exacerbations. Because eosinophils are the prominent leukocytes in the airways of 60–70% of patients with asthma, we evaluated the effects of eosinophils on a common respiratory virus, parainfluenza 1, in the lung. Eosinophils recruited to the airways of wild-type mice after ovalbumin sensitization and challenge significantly decreased parainfluenza virus RNA in the lungs 4 days after infection compared with nonsensitized animals. This antiviral effect was also seen in IL-5 transgenic mice with an abundance of airway eosinophils (NJ.1726) but was lost in transgenic eosinophil-deficient mice (PHIL) and in IL-5 transgenic mice crossed with eosinophil-deficient mice (NJ.1726-PHIL). Loss of the eosinophil granule protein eosinophil peroxidase, using eosinophil peroxidase–deficient transgenic mice, did not reduce eosinophils’ antiviral effect. Eosinophil antiviral mechanisms were also explored in vitro. Isolated human eosinophils significantly reduced parainfluenza virus titers. This effect did not involve degradation of viral RNA by eosinophil granule RNases. However, eosinophils treated with a nitric oxide synthase inhibitor lost their antiviral activity, suggesting eosinophils attenuate viral infectivity through production of nitric oxide. Consequently, eosinophil nitric oxide production was measured with an intracellular fluorescent probe. Eosinophils produced nitric oxide in response to virus and to a synthetic agonist of the virus-sensing innate immune receptor, Toll-like receptor (TLR) 7. IFNγ increased expression of eosinophil TLR7 and potentiated TLR7-induced nitric oxide production. These results suggest that eosinophils promote viral clearance in the lung and contribute to innate immune responses against respiratory virus infections in humans. PMID:27049514

Human and Mouse Eosinophils Have Antiviral Activity against Parainfluenza Virus.

PubMed

Drake, Matthew G; Bivins-Smith, Elizabeth R; Proskocil, Becky J; Nie, Zhenying; Scott, Gregory D; Lee, James J; Lee, Nancy A; Fryer, Allison D; Jacoby, David B

2016-09-01

Respiratory viruses cause asthma exacerbations. Because eosinophils are the prominent leukocytes in the airways of 60-70% of patients with asthma, we evaluated the effects of eosinophils on a common respiratory virus, parainfluenza 1, in the lung. Eosinophils recruited to the airways of wild-type mice after ovalbumin sensitization and challenge significantly decreased parainfluenza virus RNA in the lungs 4 days after infection compared with nonsensitized animals. This antiviral effect was also seen in IL-5 transgenic mice with an abundance of airway eosinophils (NJ.1726) but was lost in transgenic eosinophil-deficient mice (PHIL) and in IL-5 transgenic mice crossed with eosinophil-deficient mice (NJ.1726-PHIL). Loss of the eosinophil granule protein eosinophil peroxidase, using eosinophil peroxidase-deficient transgenic mice, did not reduce eosinophils' antiviral effect. Eosinophil antiviral mechanisms were also explored in vitro. Isolated human eosinophils significantly reduced parainfluenza virus titers. This effect did not involve degradation of viral RNA by eosinophil granule RNases. However, eosinophils treated with a nitric oxide synthase inhibitor lost their antiviral activity, suggesting eosinophils attenuate viral infectivity through production of nitric oxide. Consequently, eosinophil nitric oxide production was measured with an intracellular fluorescent probe. Eosinophils produced nitric oxide in response to virus and to a synthetic agonist of the virus-sensing innate immune receptor, Toll-like receptor (TLR) 7. IFNγ increased expression of eosinophil TLR7 and potentiated TLR7-induced nitric oxide production. These results suggest that eosinophils promote viral clearance in the lung and contribute to innate immune responses against respiratory virus infections in humans.

RIG-I in RNA virus recognition

PubMed Central

Kell, Alison M.; Gale, Michael

2015-01-01

Antiviral immunity is initiated upon host recognition of viral products via non-self molecular patterns known as pathogen-associated molecular patterns (PAMPs). Such recognition initiates signaling cascades that induce intracellular innate immune defenses and an inflammatory response that facilitates development of the acquired immune response. The retinoic acid-inducible gene I (RIG-I) and the RIG-I-like receptor (RLR) protein family are key cytoplasmic pathogen recognition receptors that are implicated in the recognition of viruses across genera and virus families, including functioning as major sensors of RNA viruses, and promoting recognition of some DNA viruses. RIG-I, the charter member of the RLR family, is activated upon binding to PAMP RNA. Activated RIG-I signals by interacting with the adapter protein MAVS leading to a signaling cascade that activates the transcription factors IRF3 and NF-κB. These actions induce the expression of antiviral gene products and the production of type I and III interferons that lead to an antiviral state in the infected cell and surrounding tissue. RIG-I signaling is essential for the control of infection by many RNA viruses. Recently, RIG-I crosstalk with other pathogen recognition receptors and components of the inflammasome has been described. In this review, we discuss the current knowledge regarding the role of RIG-I in recognition of a variety of virus families and its role in programming the adaptive immune response through cross-talk with parallel arms of the innate immune system, including how RIG-I can be leveraged for antiviral therapy. PMID:25749629

The [Mo₆Cl14]2- Cluster is Biologically Secure and Has Anti-Rotavirus Activity In Vitro.

PubMed

Rojas-Mancilla, Edgardo; Oyarce, Alexis; Verdugo, Viviana; Morales-Verdejo, Cesar; Echeverria, Cesar; Velásquez, Felipe; Chnaiderman, Jonas; Valiente-Echeverría, Fernando; Ramirez-Tagle, Rodrigo

2017-07-05

The molybdenum cluster [Mo₆Cl 14 ] 2- is a fluorescent component with potential for use in cell labelling and pharmacology. Biological safety and antiviral properties of the cluster are as yet unknown. Here, we show the effect of acute exposition of human cells and red blood cells to the molybdenum cluster and its interaction with proteins and antiviral activity in vitro. We measured cell viability of HepG2 and EA.hy926 cell lines exposed to increasing concentrations of the cluster (0.1 to 250 µM), by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Hemolysis and morphological alterations of red blood cells, obtained from healthy donors, exposed to the cluster (10 to 200 µM) at 37 °C were analyzed. Furthermore, quenching of tryptophan residues of albumin was performed. Finally, plaque formation by rotavirus SA11 in MA104 cells treated with the cluster (100 to 300 µM) were analyzed. We found that all doses of the cluster showed similar cell viability, hemolysis, and morphology values, compared to control. Quenching of tryptophan residues of albumin suggests a protein-cluster complex formation. Finally, the cluster showed antiviral activity at 300 µM. These results indicate that the cluster [Mo₆Cl 14 ] 2- could be intravenously administered in animals at therapeutic doses for further in vivo studies and might be studied as an antiviral agent.

Synergistic activity of tenofovir and nevirapine combinations released from polycaprolactone matrices for potential enhanced prevention of HIV infection through the vaginal route.

PubMed

Dang, Nhung T T; Sivakumaran, Haran; Harrich, David; Shaw, Paul N; Davis-Poynter, Nicholas; Coombes, Allan G A

2014-10-01

Polycaprolactone (PCL) matrices were simultaneously loaded with the antiviral agents, tenofovir (TFV) and nevirapine (NVP), in combination to provide synergistic activity in the prevention of HIV transmission through the vaginal route. TFV and NVP were incorporated in PCL matrices at theoretical loadings of 10%TFV-10% NVP, 5%TFV-5%NVP and 5%TFV-10%NVP, measured with respect to the PCL content of the matrices. Actual TFV loadings ranged from 2.1% to 4.2% equating to loading efficiencies of about 41-42%. The actual loadings of NVP were around half those of TFV (1.2-1.9%), resulting in loading efficiencies ranging from 17.2% to 23.5%. Approximately 80% of the initial content of TFV was released from the PCL matrices into simulated vaginal fluid (SVF) over a period of 30 days, which was almost double the cumulative release of NVP (40-45%). The release kinetics of both antivirals over 30 days were found to be described most satisfactorily by the Higuchi model. In vitro assay of release media containing combinations of TFV and NVP released from PCL matrices confirmed a potential synergistic/additive effect of the released antivirals on HIV-1 infection of HeLa cells. These findings indicate that PCL matrices loaded with combinations of TFV and NVP provide an effective strategy for the sustained vaginal delivery of antivirals with synergistic/additive activity. Copyright © 2014 Elsevier B.V. All rights reserved.

Sulfamoylbenzamide Derivatives Inhibit the Assembly of Hepatitis B Virus Nucleocapsids

PubMed Central

Campagna, Matthew R.; Liu, Fei; Mao, Richeng; Mills, Courtney; Cai, Dawei; Guo, Fang; Zhao, Xuesen; Ye, Hong; Cuconati, Andrea; Guo, Haitao; Chang, Jinhong; Xu, Xiaodong; Block, Timothy M.

2013-01-01

Chronic hepatitis B virus (HBV) infection, a serious public health problem leading to cirrhosis and hepatocellular carcinoma, is currently treated with either pegylated alpha interferon (pegIFN-α) or one of the five nucleos(t)ide analogue viral DNA polymerase inhibitors. However, neither pegIFN-α nor nucleos(t)ide analogues are capable of reliably curing the viral infection. In order to develop novel antiviral drugs against HBV, we established a cell-based screening assay by using an immortalized mouse hepatocyte-derived stable cell line supporting a high level of HBV replication in a tetracycline-inducible manner. Screening of a library consisting of 26,900 small molecules led to the discovery of a series of sulfamoylbenzamide (SBA) derivatives that significantly reduced the amount of cytoplasmic HBV DNA. Structure-activity relationship studies have thus far identified a group of fluorine-substituted SBAs with submicromolar antiviral activity against HBV in human hepatoma cells. Mechanistic analyses reveal that the compounds dose dependently inhibit the formation of pregenomic RNA (pgRNA)-containing nucleocapsids of HBV but not other animal hepadnaviruses, such as woodchuck hepatitis virus (WHV) and duck hepatitis B virus (DHBV). Moreover, heterologous genetic complementation studies of capsid protein, DNA polymerase, and pgRNA between HBV and WHV suggest that HBV capsid protein confers sensitivity to the SBAs. In summary, SBAs represent a novel chemical entity with superior activity and a unique antiviral mechanism and are thus warranted for further development as novel antiviral therapeutics for the treatment of chronic hepatitis B. PMID:23576513

Bioactive activities of natural products against herpesvirus infection.

PubMed

Son, Myoungki; Lee, Minjung; Sung, Gi-Ho; Lee, Taeho; Shin, Yu Su; Cho, Hyosun; Lieberman, Paul M; Kang, Hyojeung

2013-10-01

More than 90% of adults have been infected with at least one human herpesvirus, which establish long-term latent infection for the life of the host. While anti-viral drugs exist that limit herpesvirus replication, many of these are ineffective against latent infection. Moreover, drug-resistant strains of herpesvirus emerge following chemotherapeutic treatment. For example, resistance to acyclovir and related nucleoside analogues can occur when mutations arise in either HSV thymidine kinase or DNA polymerases. Thus, there exists an unmet medical need to develop new anti-herpesvirus agents with different mechanisms of action. In this Review, we discuss the promise of anti-herpetic substances derived from natural products including extracts and pure compounds from potential herbal medicines. One example is Glycyrrhizic acid isolated from licorice that shows promising antiviral activity towards human gammaherpesviruses. Secondly, we discuss anti-herpetic mechanisms utilized by several natural products in molecular level. While nucleoside analogues inhibit replicating herpesviruses in lytic replication, some natural products can disrupt the herpesvirus latent infection in the host cell. In addition, natural products can stimulate immune responses against herpesviral infection. These findings suggest that natural products could be one of the best choices for development of new treatments for latent herpesvirus infection, and may provide synergistic anti-viral activity when supplemented with nucleoside analogues. Therefore, it is important to identify which natural products are more efficacious anti-herpetic agents, and to understand the molecular mechanism in detail for further advance in the anti-viral therapies.

Anti-herpes simplex virus 1 and immunomodulatory activities of a poly-γ- glutamic acid from Bacillus horneckiae strain APA of shallow vent origin.

PubMed

Marino-Merlo, Francesca; Papaianni, Emanuela; Maugeri, Teresa L; Zammuto, Vincenzo; Spanò, Antonio; Nicolaus, Barbara; Poli, Annarita; Di Donato, Paola; Mosca, Claudia; Mastino, Antonio; Gugliandolo, Concetta

2017-10-01

Herpes simplex virus type 1 (HSV-1) is responsible of common and widespread viral infections in humans through the world, and of rare, but extremely severe, clinical syndromes in the central nervous system. The emergence of resistant strains to drugs actually in use encourages the searching for novel antiviral compounds, including those of natural origin. In this study, the recently described poly-γ-glutamic acid (γ-PGA-APA), produced by the marine thermotolerant Bacillus horneckiae strain APA, and previously shown to possess biological and antiviral activity, was evaluated for its anti-HSV-1 and immunomodulatory properties. The biopolymer hindered the HSV-1 infection in the very early phase of virus replication. In addition, the γ-PGA-APA was shown to exert low cytotoxicity and noticeable immunomodulatory activities towards TNF-α and IL-1β gene expression. Moreover, the capacity to positively modulate the transcriptional activity of the cytokine genes was paired with increased level of activation of the transcription factor NF-kB by γ-PGA-APA. Overall, as non-cytotoxic biopolymer able to contribute in the antiviral defense against HSV-1, γ-PGA-APA could lead to the development of novel natural drugs for alternative therapies.

Activity of andrographolide against dengue virus.

PubMed

Panraksa, Patcharee; Ramphan, Suwipa; Khongwichit, Sarawut; Smith, Duncan R

2017-03-01

Dengue is the most prevalent arthropod-transmitted viral illness of humans, with an estimated 100 million symptomatic infections occurring each year and more than 2.5 billion people living at risk of infection. There are no approved antiviral agents against dengue virus, and there is only limited introduction of a dengue vaccine in some countries. Andrographolide is derived from Andrographis paniculata, a medicinal plant traditionally used to treat a number of conditions including infections. The antiviral activity of andrographolide against dengue virus (DENV) serotype 2 was evaluated in two cell lines (HepG2 and HeLa) while the activity against DENV 4 was evaluated in one cell line (HepG2). Results showed that andrographolide had significant anti-DENV activity in both cell lines, reducing both the levels of cellular infection and virus output, with 50% effective concentrations (EC 50 ) for DENV 2 of 21.304 μM and 22.739 μM for HepG2 and HeLa respectively. Time of addition studies showed that the activity of andrographolide was confined to a post-infection stage. These results suggest that andrographolide has the potential for further development as an anti-viral agent for dengue virus infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Dancing with chemical formulae of antivirals: A panoramic view (Part 2).

PubMed

De Clercq, Erik

2013-11-15

In this second part of "Dancing with antivirals as chemical formulae" I will focus on a number of chemical compounds that in the last few years have elicited more than common attraction from a commercial viewpoint: (i) favipiravir (T-705), as it is active against influenza, but also several other RNA viruses; (ii) neuraminidase inhibitors such as zanamivir and oseltamivir; (iii) peramivir and laninamivir octanoate, which might be effective against influenza virus following a single (intravenous or inhalation) administration; (iv) sofosbuvir, the (anticipated) cornerstone for the interferon-free therapy of HCV infections; (v) combinations of DAAs (direct antiviral agents) to achieve, in no time, a sustained virus response (SVR) against HCV infection; (vi) HIV protease inhibitors, the latest and most promising being darunavir; (vii) the integrase inhibitors (INIs) (raltegravir, elvitegravir, dolutegravir), representing a new dimension in the anti-HIV armamentarium; (viii), a new class of helicase primase inhibitors (HPIs) that may exceed acyclovir and the other anti-herpes compounds in both potency and safety; (ix) CMX-001, as the latest of Dr. Antonín Holý's legacy for its activity against poxviruses and CMV infections, and (x) noroviruses for which the ideal antiviral compounds are still awaited for. Copyright © 2013 Elsevier Inc. All rights reserved.

Cloning, expression and antiviral activity of IFNγ from the Australian fruit bat, Pteropus alecto.

PubMed

Janardhana, Vijaya; Tachedjian, Mary; Crameri, Gary; Cowled, Chris; Wang, Lin-Fa; Baker, Michelle L

2012-03-01

Bats are natural reservoir hosts to a variety of viruses, many of which cause morbidity and mortality in other mammals. Currently there is a paucity of information regarding the nature of the immune response to viral infections in bats, partly due to a lack of appropriate bat specific reagents. IFNγ plays a key role in controlling viral replication and coordinating a response for long term control of viral infection. Here we describe the cloning and expression of IFNγ from the Australian flying fox, Pteropus alecto and the generation of mouse monoclonal and chicken egg yolk antibodies specific to bat IFNγ. Our results demonstrate that P. alecto IFNγ is conserved with IFNγ from other species and is induced in bat splenocytes following stimulation with T cell mitogens. P. alecto IFNγ has antiviral activity on Semliki forest virus in cell lines from P. alecto and the microbat, Tadarida brasiliensis. Additionally recombinant bat IFNγ was able to mitigate Hendra virus infection in P. alecto cells. These results provide the first evidence for an antiviral role for bat IFNγin vitro in addition to the application of important immunological reagents for further studies of bat antiviral immunity. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Baicalin from Scutellaria baicalensis blocks respiratory syncytial virus (RSV) infection and reduces inflammatory cell infiltration and lung injury in mice

PubMed Central

Shi, Hengfei; Ren, Ke; Lv, Baojie; Zhang, Wei; Zhao, Ying; Tan, Ren Xiang; Li, Erguang

2016-01-01

The roots of Scutellaria baicalensis has been used as a remedy for inflammatory and infective diseases for thousands of years. We evaluated the antiviral activity against respiratory syncytial virus (RSV) infection, the leading cause of childhood infection and hospitalization. By fractionation and chromatographic analysis, we determined that baicalin was responsible for the antiviral activity of S. baicalensis against RSV infection. The concentration for 50% inhibition (IC50) of RSV infection was determined at 19.9 ± 1.8 μM, while the 50% cytotoxic concentration (CC50) was measured at 370 ± 10 μM. We then used a mouse model of RSV infection to further demonstrate baicalin antiviral effect. RSV infection caused significant lung injury and proinflammatory response, including CD4 and CD8 T lymphocyte infiltration. Baicalin treatment resulted in reduction of T lymphocyte infiltration and gene expression of proinflammatory factors, while the treatment moderately reduced RSV titers recovered from the lung tissues. T lymphocyte infiltration and cytotoxic T lymphocyte modulated tissue damage has been identified critical factors of RSV disease. The study therefore demonstrates that baicalin subjugates RSV disease through antiviral and anti-inflammatory effect. PMID:27767097

HIV-1 adaptation studies reveal a novel Env-mediated homeostasis mechanism for evading lethal hypermutation by APOBEC3G

PubMed Central

Ikeda, Terumasa; Albin, John S.; Li, Ming; Thali, Markus

2018-01-01

HIV-1 replication normally requires Vif-mediated neutralization of APOBEC3 antiviral enzymes. Viruses lacking Vif succumb to deamination-dependent and -independent restriction processes. Here, HIV-1 adaptation studies were leveraged to ask whether viruses with an irreparable vif deletion could develop resistance to restrictive levels of APOBEC3G. Several resistant viruses were recovered with multiple amino acid substitutions in Env, and these changes alone are sufficient to protect Vif-null viruses from APOBEC3G-dependent restriction in T cell lines. Env adaptations cause decreased fusogenicity, which results in higher levels of Gag-Pol packaging. Increased concentrations of packaged Pol in turn enable faster virus DNA replication and protection from APOBEC3G-mediated hypermutation of viral replication intermediates. Taken together, these studies reveal that a moderate decrease in one essential viral activity, namely Env-mediated fusogenicity, enables the virus to change other activities, here, Gag-Pol packaging during particle production, and thereby escape restriction by the antiviral factor APOBEC3G. We propose a new paradigm in which alterations in viral homeostasis, through compensatory small changes, constitute a general mechanism used by HIV-1 and other viral pathogens to escape innate antiviral responses and other inhibitions including antiviral drugs. PMID:29677220

Effect of New Antiviral Agent Camphecin on Behavior of Mice.

PubMed

Babina, A V; Lavrinenko, V A; Yarovaya, O I; Salakhutdinov, N F

2017-01-01

We studied the effect of camphecin (1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene-aminoethanol) on mouse behavior in the open-field test. Camphecin possesses antiviral activity and inhibits viral replication, but its influence on the nervous system is poorly studied. Single camphecin injection produced no significant changes in behavioral patterns. Chronic camphecin administration (5 times over 2 weeks) to mice of different strains had no significant influence on open field behavior (motor, exploratory activity, anxiety, emotional state and vegetative functions). The findings are discussed in the context of neutral influence of camphecin on animal behavior.

Prophylactic Valacyclovir to Prevent Outbreaks of Primary Herpes Gladiatorum at a 28-Day Wrestling Camp: A 10-Year Review.

PubMed

Anderson, B J; McGuire, Dennis P; Reed, Megan; Foster, Monique; Ortiz, Deanna

2016-07-01

To determine efficacy of using oral antiviral medication to reduce herpes gladiatorum (HG) at summer high-school wrestling camps. Usage of antiviral medication hypothetically reduces the likelihood of HG outbreaks. This is an observational study examining the effectiveness of oral antiviral medications in reducing outbreaks of HG because of Herpes Simplex type-1 virus (HSV). A 28-day high-school summer wrestling camp at the University of Minnesota from 2003 to 2012. Each summer approximately 300 high-school wrestlers, age 13 to 18 years of age, participated in this camp. All athletes were recommended to take valacyclovir 1 g once a day for the duration of the camp. Athletes who did not use any antiviral medication comprised the comparison group for this study. Individuals were screened daily and those with outbreaks of HG were withheld from practice for 120 hours in accordance with National Collegiate Athletic Association/National Federation of State High School Associations guidelines. To measure viral outbreaks of HG due to HSV-1, determine level of compliance, and determine efficacy of antiviral medication in reducing the occurrence of HG at this 28-day wrestling camp. Of the 2793 athletes who completed camp, 1995 (71%) used antiviral medication, and 36 outbreaks occurred. Eighty-four athletes had a known history of HG/recurrent herpes labialis. Overall, prophylactic antiviral medication resulted in an 84.7% decrease in the probability of an outbreak. Prophylactic valacyclovir (1 g daily) lowered the incidence of individual outbreaks by 89.5%. Prophylactic use of valacyclovir 1 g once a day is efficacious in lowering the incidence of HSV outbreaks among adolescents at a 28-day wrestling camp.

New 1-indanone thiosemicarbazone derivatives active against BVDV.

PubMed

Finkielsztein, Liliana M; Castro, Eliana F; Fabián, Lucas E; Moltrasio, Graciela Y; Campos, Rodolfo H; Cavallaro, Lucía V; Moglioni, Albertina G

2008-08-01

Identification of new therapeutic agents for the treatment of viral diseases represents an area of active investigation. In an effort to develop new antiviral compounds, a series of 1-indanone thiosemicarbazone derivatives were synthesized. These derivatives were structurally characterized using several spectroscopic techniques and evaluated against bovine viral diarrhoea virus as a surrogate model for hepatitis C virus. Thiosemicarbazone 2m showed potent anti-bovine viral diarrhoea virus activity with a higher selectivity index (SI=80.29) than that of ribavirin (SI=11.64). This result determines the potentiality of these thiosemicarbazones as antiviral agents for the treatment of infections caused by other highly related members of Flaviviridae family, as hepatitis C virus.

Cell- and virus-mediated regulation of the barrier-to-autointegration factor's phosphorylation state controls its DNA binding, dimerization, subcellular localization, and antipoxviral activity.

PubMed

Jamin, Augusta; Wicklund, April; Wiebe, Matthew S

2014-05-01

Barrier-to-autointegration factor (BAF) is a DNA binding protein with multiple cellular functions, including the ability to act as a potent defense against vaccinia virus infection. This antiviral function involves BAF's ability to condense double-stranded DNA and subsequently prevent viral DNA replication. In recent years, it has become increasingly evident that dynamic phosphorylation involving the vaccinia virus B1 kinase and cellular enzymes is likely a key regulator of multiple BAF functions; however, the precise mechanisms are poorly understood. Here we analyzed how phosphorylation impacts BAF's DNA binding, subcellular localization, dimerization, and antipoxviral activity through the characterization of BAF phosphomimetic and unphosphorylatable mutants. Our studies demonstrate that increased phosphorylation enhances BAF's mobilization from the nucleus to the cytosol, while dephosphorylation restricts BAF to the nucleus. Phosphorylation also impairs both BAF's dimerization and its DNA binding activity. Furthermore, our studies of BAF's antiviral activity revealed that hyperphosphorylated BAF is unable to suppress viral DNA replication or virus production. Interestingly, the unphosphorylatable BAF mutant, which is capable of binding DNA but localizes predominantly to the nucleus, was also incapable of suppressing viral replication. Thus, both DNA binding and localization are important determinants of BAF's antiviral function. Finally, our examination of how phosphatases are involved in regulating BAF revealed that PP2A dephosphorylates BAF during vaccinia infection, thus counterbalancing the activity of the B1 kinase. Altogether, these data demonstrate that phosphoregulation of BAF by viral and cellular enzymes modulates this protein at multiple molecular levels, thus determining its effectiveness as an antiviral factor and likely other functions as well. The barrier-to-autointegration factor (BAF) contributes to cellular genomic integrity in multiple ways, the best characterized of which are as a host defense against cytoplasmic DNA and as a regulator of mitotic nuclear reassembly. Although dynamic phosphorylation involving both viral and cellular enzymes is likely a key regulator of multiple BAF functions, the precise mechanisms involved are poorly understood. Here we demonstrate that phosphorylation coordinately regulates BAF's DNA binding, subcellular localization, dimerization, and antipoxviral activity. Overall, our findings provide new insights into how phosphoregulation of BAF modulates this protein at multiple levels and governs its effectiveness as an antiviral factor against foreign DNA.

Changes in Liver Volume in Patients with Chronic Hepatitis C Undergoing Antiviral Therapy

PubMed Central

Fitzpatrick, Julie A.; Kim, Jin Un; Cobbold, Jeremy F.L.; McPhail, Mark J.W.; Crossey, Mary M.E.; Bak-Bol, Aluel A.; Zaky, Ashraf; Taylor-Robinson, Simon D.

2016-01-01

Aim Liver volumetric analysis has not been used to detect hepatic remodelling during antiviral therapy before. We measured liver volume (LV) changes on volumetric magnetic resonance imaging during hepatitis C antiviral therapy. Methods 22 biopsy-staged patients (median [range] age 4519–65 years; 9F, 13M) with chronic hepatitis C virus infection were studied. LV was measured at the beginning, end of treatment and 6 months post-treatment using 3D T1-weighted acquisition, normalised to patient weight. Liver outlines were drawn manually on 4 mm thick image slices and LV calculated. Inter-observer agreement was analysed. Patients were also assessed longitudinally using biochemical parameters and liver stiffness using Fibroscan™. Results Sustained viral response (SVR) was achieved in 13 patients with a mean baseline LV/kg of 0.022 (SD 0.004) L/kg. At the end of treatment, the mean LV/kg was 0.025 (SD 0.004, P = 0.024 cf baseline LV/kg) and 0.026 (SD 0.004, P = 0.008 cf baseline LV/kg) 6 months post-treatment (P = 0.030 cf baseline, P = 0.004). Body weight-corrected end of treatment LV change was significantly higher in patients with SVR compared to patients not attaining SVR (P = 0.050). End of treatment LV change was correlated to initial ALT (R2 = 0.479, P = 0.037), but not APRI, AST, viral load or liver stiffness measurements. There was a correlation of 0.89 between observers for measured slice thickness. Conclusions LV increased during anti-viral treatment, while the body weight-corrected LV increase persisted post-antiviral therapy and was larger in patients with SVR. PMID:27194891

Changes in Liver Volume in Patients with Chronic Hepatitis C Undergoing Antiviral Therapy.

PubMed

Fitzpatrick, Julie A; Kim, Jin Un; Cobbold, Jeremy F L; McPhail, Mark J W; Crossey, Mary M E; Bak-Bol, Aluel A; Zaky, Ashraf; Taylor-Robinson, Simon D

2016-03-01

Liver volumetric analysis has not been used to detect hepatic remodelling during antiviral therapy before. We measured liver volume (LV) changes on volumetric magnetic resonance imaging during hepatitis C antiviral therapy. 22 biopsy-staged patients (median [range] age 45(19-65) years; 9F, 13M) with chronic hepatitis C virus infection were studied. LV was measured at the beginning, end of treatment and 6 months post-treatment using 3D T1-weighted acquisition, normalised to patient weight. Liver outlines were drawn manually on 4 mm thick image slices and LV calculated. Inter-observer agreement was analysed. Patients were also assessed longitudinally using biochemical parameters and liver stiffness using Fibroscan™. Sustained viral response (SVR) was achieved in 13 patients with a mean baseline LV/kg of 0.022 (SD 0.004) L/kg. At the end of treatment, the mean LV/kg was 0.025 (SD 0.004, P = 0.024 cf baseline LV/kg) and 0.026 (SD 0.004, P = 0.008 cf baseline LV/kg) 6 months post-treatment (P = 0.030 cf baseline, P = 0.004). Body weight-corrected end of treatment LV change was significantly higher in patients with SVR compared to patients not attaining SVR (P = 0.050). End of treatment LV change was correlated to initial ALT (R (2) = 0.479, P = 0.037), but not APRI, AST, viral load or liver stiffness measurements. There was a correlation of 0.89 between observers for measured slice thickness. LV increased during anti-viral treatment, while the body weight-corrected LV increase persisted post-antiviral therapy and was larger in patients with SVR.

Activation of peripheral blood mononuclear cells by dengue virus infection depotentiates balapiravir.

PubMed

Chen, Yen-Liang; Abdul Ghafar, Nahdiyah; Karuna, Ratna; Fu, Yilong; Lim, Siew Pheng; Schul, Wouter; Gu, Feng; Herve, Maxime; Yokohama, Fumiaki; Wang, Gang; Cerny, Daniela; Fink, Katja; Blasco, Francesca; Shi, Pei-Yong

2014-02-01

In a recent clinical trial, balapiravir, a prodrug of a cytidine analog (R1479), failed to achieve efficacy (reducing viremia after treatment) in dengue patients, although the plasma trough concentration of R1479 remained above the 50% effective concentration (EC(50)). Here, we report experimental evidence to explain the discrepancy between the in vitro and in vivo results and its implication for drug development. R1479 lost its potency by 125-fold when balapiravir was used to treat primary human peripheral blood mononuclear cells (PBMCs; one of the major cells targeted for viral replication) that were preinfected with dengue virus. The elevated EC(50) was greater than the plasma trough concentration of R1479 observed in dengue patients treated with balapiravir and could possibly explain the efficacy failure. Mechanistically, dengue virus infection triggered PBMCs to generate cytokines, which decreased their efficiency of conversion of R1479 to its triphosphate form (the active antiviral ingredient), resulting in decreased antiviral potency. In contrast to the cytidine-based compound R1479, the potency of an adenosine-based inhibitor of dengue virus (NITD008) was much less affected. Taken together, our results demonstrate that viral infection in patients before treatment could significantly affect the conversion of the prodrug to its active form; such an effect should be calculated when estimating the dose efficacious for humans.

[Comparative analysis of the effectiveness of antiviral therapy of children with infectious mononucleosis].

PubMed

Baranova, I P; Kurmaeva, D Iu

2013-01-01

A group of 126 children (4 to 7 years old) with infectious mononucleosis received basic therapy in combination with nonspecific antiviral drugs. The same therapeutic efficiency was observed for cycloferon and genferon light included in complex treatment of infectious mononucleosis in children. The use of cycloferon (10 mg/kg i.m., single daily injection for 10 days) prevents the development of frequent acute respiratory viral infections in the period of convalescence.

Antiviral Defense and Innate Immune Memory in the Oyster.

PubMed

Green, Timothy J; Speck, Peter

2018-03-16

The Pacific oyster, Crassostrea gigas , is becoming a valuable model for investigating antiviral defense in the Lophotrochozoa superphylum. In the past five years, improvements to laboratory-based experimental infection protocols using Ostreid herpesvirus I (OsHV-1) from naturally infected C. gigas combined with next-generation sequencing techniques has revealed that oysters have a complex antiviral response involving the activation of all major innate immune pathways. Experimental evidence indicates C. gigas utilizes an interferon-like response to limit OsHV-1 replication and spread. Oysters injected with a viral mimic (polyI:C) develop resistance to OsHV-1. Improved survival following polyI:C injection was found later in life (within-generational immune priming) and in the next generation (multi-generational immune priming). These studies indicate that the oyster's antiviral defense system exhibits a form of innate immune-memory. An important priority is to identify the molecular mechanisms responsible for this phenomenon. This knowledge will motivate the development of practical and cost-effective treatments for improving oyster health in aquaculture.

ERRα negatively regulates type I interferon induction by inhibiting TBK1-IRF3 interaction

PubMed Central

Tian, Yinyin; Wei, Congwen; Zhu, Yongjie; Li, Feng; Zhang, Pingping; Wang, Penghao; Zhang, Yanhong

2017-01-01

Estrogen-related receptor α (ERRα) is a member of the nuclear receptor superfamily controlling energy homeostasis; however, its precise role in regulating antiviral innate immunity remains to be clarified. Here, we showed that ERRα deficiency conferred resistance to viral infection both in vivo and in vitro. Mechanistically, ERRα inhibited the production of type-I interferon (IFN-I) and the expression of multiple interferon-stimulated genes (ISGs). Furthermore, we found that viral infection induced TBK1-dependent ERRα stabilization, which in turn associated with TBK1 and IRF3 to impede the formation of TBK1-IRF3, IRF3 phosphorylation, IRF3 dimerization, and the DNA binding affinity of IRF3. The effect of ERRα on IFN-I production was independent of its transcriptional activity and PCG-1α. Notably, ERRα chemical inhibitor XCT790 has broad antiviral potency. This work not only identifies ERRα as a critical negative regulator of antiviral signaling, but also provides a potential target for future antiviral therapy. PMID:28591144

3-Hydroxypyrimidine-2,4-dione-5-N-benzylcarboxamides potently inhibit HIV-1 integrase and RNase H

PubMed Central

Wu, Bulan; Tang, Jing; Wilson, Daniel J.; Huber, Andrew D.; Casey, Mary C.; Ji, Juan; Kankanala, Jayakanth; Xie, Jiashu; Sarafianos, Stefan G.; Wang, Zhengqiang

2016-01-01

Resistance selection by human immunodeficiency virus (HIV) towards known drug regimens necessitates the discovery of structurally novel antivirals with a distinct resistance profile. Based on our previously reported 3-hydroxypyrimidine-2,4-dione (HPD) core we have designed and synthesized a new integrase strand transfer (INST) inhibitor type featuring a 5-N-benzylcarboxamide moiety. Significantly, the 6-alkylamino variant of this new chemotype consistently conferred low nanomolar inhibitory activity against HIV-1. Extended antiviral testing against a few raltegravir-resistant HIV-1 clones revealed a resistance profile similar to that of the second generation INST inhibitor (INSTIs) dolutegravir. Although biochemical testing and molecular modeling also strongly corroborate the inhibition of INST as the antiviral mechanism of action, selected antiviral analogues also potently inhibited reverse transcriptase (RT) associated RNase H, implying potential dual target inhibition. In vitro ADME assays demonstrated that this novel chemotype possesses largely favorable physicochemical properties suitable for further development. PMID:27283261

Direct-acting Antivirals and Host-targeting Agents against the Hepatitis A Virus

PubMed Central

Kanda, Tatsuo; Nakamoto, Shingo; Wu, Shuang; Nakamura, Masato; Jiang, Xia; Haga, Yuki; Sasaki, Reina; Yokosuka, Osamu

2015-01-01

Hepatitis A virus (HAV) infection is a major cause of acute hepatitis and occasionally leads to acute liver failure in both developing and developed countries. Although effective vaccines for HAV are available, the development of new antivirals against HAV may be important for the control of HAV infection in developed countries where no universal vaccination program against HAV exists, such as Japan. There are two forms of antiviral agents against HAV: direct-acting antivirals (DAAs) and host-targeting agents (HTAs). Studies using small interfering ribonucleic acid (siRNA) have suggested that the HAV internal ribosomal entry site (IRES) is an attractive target for the control of HAV replication and infection. Among the HTAs, amantadine and interferon-lambda 1 (IL-29) inhibit HAV IRES-mediated translation and HAV replication. Janus kinase (JAK) inhibitors inhibit La protein expression, HAV IRES activity, and HAV replication. Based on this review, both DAAs and HTAs may be needed to control effectively HAV infection, and their use should continue to be explored. PMID:26623267

Fate-Regulating Circuits in Viruses: From Discovery to New Therapy Targets

PubMed Central

Pai, Anand; Weinberger, Leor S.

2018-01-01

Current antivirals effectively target diverse viruses at various stages of their viral lifecycles. Nevertheless, curative therapy has remained elusive for important pathogens (e.g., HIV-1 and herpesviruses), in large part due to viral latency and the evolution of resistance to existing therapies. Here, we review the discovery of viral ‘master’ circuits: virus-encoded auto-regulatory gene networks that can autonomously control viral expression programs (i.e., between active, latent, and abortive fates). These circuits offer a potential new class of antivirals that could lead to intrinsic combination-antiviral therapies within a single molecule—evolutionary escape from such circuit ‘disruptors’ would require simultaneous evolution of both the cis regulatory element (e.g., the DNA-binding site) and the trans element (e.g., the transcription factor) for the circuit’s function to be recapitulated. We review the architectures of these fate-regulating master circuits in HIV-1 and the human herpesvirus cytomegalovirus (CMV) along with potential circuit-disruption strategies that may ultimately enable escape-resistant antiviral therapies. PMID:28800289

Antiviral Activity of Chlorite-Oxidized Oxyamylose, a Polyacetal Carboxylic Acid

PubMed Central

Billiau, A.; Desmyter, J.; De Somer, P.

1970-01-01

Intraperitoneal injection of chlorite-oxidized oxyamylose (COAM) protected mice against mengo, vaccinia, Semliki Forest, and influenza APR8 viruses. Topical administration in the eye of rabbits partially inhibited the development of experimental herpetic keratoconjunctivitis. COAM resembled polyacrylic acid in many aspects, but it was markedly less toxic. For systemic administration, the therapeutic index was on the order of magnitude of 1:300 to 1:500. Although the in vivo antiviral effect of COAM wore off faster than that of polyacrylic acid, protection lasted for several weeks. Against mengovirus, such prolonged protection was achieved only when polymer and virus were injected intraperitoneally. Protection against intravenous vaccinia virus was not dependent on the injection route of COAM. Experiments on the mode of action of COAM pointed to macrophages as possible mediators of the antiviral effect. The fact that small amounts of interferon appeared in the serum after administration of high doses of COAM suggests that interferon may play a role in the induction of antiviral resistance by COAM. PMID:4314554

PKACs attenuate innate antiviral response by phosphorylating VISA and priming it for MARCH5-mediated degradation

PubMed Central

Yan, Bing-Ru; Zhou, Lu; Hu, Ming-Ming; Li, Mi; Lin, Heng; Yang, Yan; Wang, Yan-Yi

2017-01-01

Sensing of viral RNA by RIG-I-like receptors initiates innate antiviral response, which is mediated by the central adaptor VISA. How the RIG-I-VISA-mediated antiviral response is terminated at the late phase of infection is enigmatic. Here we identified the protein kinase A catalytic (PKAC) subunits α and β as negative regulators of RNA virus-triggered signaling in a redundant manner. Viral infection up-regulated cellular cAMP levels and activated PKACs, which then phosphorylated VISA at T54. This phosphorylation abrogated virus-induced aggregation of VISA and primed it for K48-linked polyubiquitination and degradation by the E3 ligase MARCH5, leading to attenuation of virus-triggered induction of downstream antiviral genes. PKACs-deficiency or inactivation by the inhibitor H89 potentiated innate immunity to RNA viruses in cells and mice. Our findings reveal a critical mechanism of attenuating innate immune response to avoid host damage at the late phase of viral infection by the house-keeping PKA kinase. PMID:28934360

PKACs attenuate innate antiviral response by phosphorylating VISA and priming it for MARCH5-mediated degradation.

PubMed

Yan, Bing-Ru; Zhou, Lu; Hu, Ming-Ming; Li, Mi; Lin, Heng; Yang, Yan; Wang, Yan-Yi; Shu, Hong-Bing

2017-09-01

Sensing of viral RNA by RIG-I-like receptors initiates innate antiviral response, which is mediated by the central adaptor VISA. How the RIG-I-VISA-mediated antiviral response is terminated at the late phase of infection is enigmatic. Here we identified the protein kinase A catalytic (PKAC) subunits α and β as negative regulators of RNA virus-triggered signaling in a redundant manner. Viral infection up-regulated cellular cAMP levels and activated PKACs, which then phosphorylated VISA at T54. This phosphorylation abrogated virus-induced aggregation of VISA and primed it for K48-linked polyubiquitination and degradation by the E3 ligase MARCH5, leading to attenuation of virus-triggered induction of downstream antiviral genes. PKACs-deficiency or inactivation by the inhibitor H89 potentiated innate immunity to RNA viruses in cells and mice. Our findings reveal a critical mechanism of attenuating innate immune response to avoid host damage at the late phase of viral infection by the house-keeping PKA kinase.