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Sample records for acting antivirals daas

  1. Colitis during new direct-acting antiviral agents (DAAs) therapy with sofosbuvir, simeprevir and ribavirin for genotype 1b hepatitis C.

    PubMed

    Izzo, Ilaria; Zanotti, Paola; Chirico, Claudia; Casari, Salvatore; Villanacci, Vincenzo; Salemme, Marianna; Biasi, Luciano; Festa, Elena; Castelli, Francesco

    2016-12-01

    Since 2014 several direct-acting antivirals (DAAs) have been made available, allowing interferon-free antiviral treatments with high sustained virological response rates. Side effects are, however, a real challenge during treatment. Sarkar et al. recently published a case of colitis following initiation of sofosbuvir and simeprevir for genotype 1 hepatitis C. We report the case of a patient with no prior history of inflammatory bowel disease, who developed significant bloody diarrhea within 3 weeks of sofosbuvir/simeprevir/ribavirin initiation. Colonoscopy and biopsy suggested a drug-induced colitis.

  2. Synergy of entry inhibitors with direct-acting antivirals uncovers novel combinations for prevention and treatment of hepatitis C

    PubMed Central

    Xiao, Fei; Fofana, Isabel; Thumann, Christine; Mailly, Laurent; Alles, Roxane; Robinet, Eric; Meyer, Nicolas; Schaeffer, Mickaël; Habersetzer, François; Doffoël, Michel; Leyssen, Pieter; Neyts, Johan; Zeisel, Mirjam B; Baumert, Thomas F

    2015-01-01

    Objective Although direct-acting antiviral agents (DAAs) have markedly improved the outcome of treatment in chronic HCV infection, there continues to be an unmet medical need for improved therapies in difficult-to-treat patients as well as liver graft infection. Viral entry is a promising target for antiviral therapy. Design Aiming to explore the role of entry inhibitors for future clinical development, we investigated the antiviral efficacy and toxicity of entry inhibitors in combination with DAAs or other host-targeting agents (HTAs). Screening a large series of combinations of entry inhibitors with DAAs or other HTAs, we uncovered novel combinations of antivirals for prevention and treatment of HCV infection. Results Combinations of DAAs or HTAs and entry inhibitors including CD81-, scavenger receptor class B type I (SR-BI)- or claudin-1 (CLDN1)-specific antibodies or small-molecule inhibitors erlotinib and dasatinib were characterised by a marked and synergistic inhibition of HCV infection over a broad range of concentrations with undetectable toxicity in experimental designs for prevention and treatment both in cell culture models and in human liver-chimeric uPA/SCID mice. Conclusions Our results provide a rationale for the development of antiviral strategies combining entry inhibitors with DAAs or HTAs by taking advantage of synergy. The uncovered combinations provide perspectives for efficient strategies to prevent liver graft infection and novel interferon-free regimens. PMID:24848265

  3. Treatment of chronic hepatitis C with direct-acting antivirals: The role of resistance

    PubMed Central

    Jiménez-Pérez, Miguel; González-Grande, Rocío; España Contreras, Pilar; Pinazo Martínez, Isabel; de la Cruz Lombardo, Jesús; Olmedo Martín, Raúl

    2016-01-01

    The use of direct-acting antivirals (DAAs) to treat chronic hepatitis C has resulted in a significant increase in rates of sustained viral response (around 90%-95%) as compared with the standard treatment of peginterferon/ribavirin. Despite this, however, the rates of therapeutic failure in daily clinical practice range from 10%-15%. Most of these cases are due to the presence of resistant viral variants, resulting from mutations produced by substitutions of amino acids in the viral target protein that reduce viral sensitivity to DAAs, thus limiting the efficacy of these drugs. The high genetic diversity of hepatitis C virus has resulted in the existence of resistance-associated variants (RAVs), sometimes even before starting treatment with DAAs, though generally at low levels. These pre-existing RAVs do not appear to impact on the sustained viral response, whereas those that appear after DAA therapy could well be determinant in virological failure with future treatments. As well as the presence of RAVs, virological failure to treatment with DAAs is generally associated with other factors related with a poor response, such as the degree of fibrosis, the response to previous therapy, the viral load or the viral genotype. Nonetheless, viral breakthrough and relapse can still occur in the absence of detectable RAVs and after the use of highly effective DAAs, so that the true clinical impact of the presence of RAVs in therapeutic failure remains to be determined. PMID:27547001

  4. Real-life data on potential drug-drug interactions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER Cohort Study

    PubMed Central

    Kondili, Loreta A.; Gaeta, Giovanni Battista; Ieluzzi, Donatella; Zignego, Anna Linda; Monti, Monica; Gori, Andrea; Soria, Alessandro; Raimondo, Giovanni; Filomia, Roberto; Di Leo, Alfredo; Iannone, Andrea; Massari, Marco; Corsini, Romina; Gulminetti, Roberto; Gatti Comini, Alberto; Toniutto, Pierluigi; Dissegna, Denis; Russo, Francesco Paolo; Zanetto, Alberto; Rumi, Maria Grazia; Brancaccio, Giuseppina; Danieli, Elena; Brunetto, Maurizia Rossana; Weimer, Liliana Elena; Quaranta, Maria Giovanna; Vella, Stefano; Puoti, Massimo

    2017-01-01

    Background There are few real-life data on the potential drug-drug interactions (DDIs) between anti-HCV direct-acting antivirals (DAAs) and the comedications used. Aim To assess the potential DDIs of DAAs in HCV-infected outpatients, according to the severity of liver disease and comedication used in a prospective multicentric study. Methods Data from patients in 15 clinical centers who had started a DAA regimen and were receiving comedications during March 2015 to March 2016 were prospectively evaluated. The DDIs for each regimen and comedication were assigned according to HepC Drug Interactions (www.hep-druginteractions.org). Results Of the 449 patients evaluated, 86 had mild liver disease and 363 had moderate-to-severe disease. The use of a single comedication was more frequent among patients with mild liver disease (p = 0.03), whereas utilization of more than three drugs among those with moderate-to-severe disease (p = 0.05). Of the 142 comedications used in 86 patients with mild disease, 27 (20%) may require dose adjustment/closer monitoring, none was contraindicated. Of the 322 comedications used in 363 patients with moderate-to-severe liver disease, 82 (25%) were classified with potential DDIs that required only monitoring and dose adjustments; 10 (3%) were contraindicated in severe liver disease. In patients with mild liver disease 30% (26/86) used at least one drug with a potential DDI whereas of the 363 patients with moderate-to-severe liver disease, 161 (44%) were at risk for one or more DDI. Conclusions Based on these results, we can estimate that 30–44% of patients undergoing DAA and taking comedications are at risk of a clinically significant DDI. This data indicates the need for increased awareness of potential DDI during DAA therapy, especially in patients with moderate-to-severe liver disease. For several drugs, the recommendation related to the DDI changes from “dose adjustment/closer monitoring”, in mild to moderate liver disease, to

  5. Herpes Zoster reactivation in patients with chronic hepatitis C under treatment with directly acting antiviral agents: A case series.

    PubMed

    El Kassas, Mohamed; Wifi, Mohamed Naguib; Mahdy, Reem; Afify, Shimaa; Hafez, Enas; El Latif, Yasmeen Abd; Ezzat, Marwa; El Tahan, Adel; Youssef, Naglaa; Esmat, Gamal

    2017-03-17

    We report a series of cutaneous Herpes Zoster (HZ) reactivation cases in patients with hepatitis C virus (HCV) infection treated with directly acting antiviral (DAA) agents. Five cases were detected among 2133 treated patients with DAAs at one of the specialized viral hepatitis treatment centers in Egypt. A control group including 2300 age and sex matched HCV patients who were previously treated with pegylated interferon and ribavirin did not show any HZ reactivation reports while on treatment. None of cases had an evidence of immunosuppression or a risk factor for HZ reactivation. The DAAs used regimens were sofosbuvir/daclatasvir in 4 cases and sofosbuvir/simeprevir in one case. HCV clearance with antiviral therapy may bring immune changes causing reactivation of other latent viral infections like HZ. A high index of clinical suspicion may be needed to guarantee early and prompt management of such cases.

  6. Effectiveness of direct-acting antivirals in Hepatitis C virus infection in haemodialysis patients.

    PubMed

    Abad, Soraya; Vega, Almudena; Rincón, Diego; Hernández, Eduardo; Mérida, Evangelina; Macías, Nicolás; Muñoz, Raquel; Milla, Mónica; Luño, Jose; López-Gómez, Juan Manuel

    2016-11-30

    Hepatitis C virus (HCV) infection is highly prevalent among patients on haemodialysis and leads to a poorer prognosis compared to patients who do not have said infection. Treatment with interferon and ribavirin is poorly tolerated and there are limited data on the experience with new direct-acting antivirals (DAAs). The aim of this study is to retrospectively analyse the current prevalence of HCV infection and efficacy and safety results with different DAA regimens in the haemodialysis population of 2hospital areas. This is a multicentre, retrospective and observational study in which HCV antibodies were analysed in 465 patients, with positive antibody findings in 54 of them (11.6%). Among these, 29 cases (53.7%) with genotypes 1 and 4 were treated with different DAA regimens, including combinations of paritaprevir/ritonavir, ombitasvir, dasabuvir, sofosbuvir, simeprevir, daclatasvir and ledipasvir, with/without ribavirin. Mean age was 53.3±7.9 years, 72.4% of patients were male and the most important aetiology of chronic kidney disease involved glomerular abnormalities. In 100% of cases, a sustained viral response was achieved after 24 weeks, regardless of DAA regimen received. Adverse effects were not relevant and no case required stopping treatment. In 15 cases, ribavirin was combined with the DAA. In these cases, the most significant adverse effect was anaemic tendency, which was reflected in the increase of the dose of erythropoietin stimulating agents, although none required transfusions. In summary, we conclude that new DAAs for the treatment of HCV in haemodialysis patients are highly effective with minimal adverse effects; it is a very important advance in HCV management. These patients are therefore expected to have a much better prognosis than they have had until very recently.

  7. Statin (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor)-based therapy for hepatitis C virus (HCV) infection-related diseases in the era of direct-acting antiviral agents

    PubMed Central

    Kishta, Sara Sobhy; Kishta, Sobhy Ahmed; El-Shenawy, Reem

    2017-01-01

    Recent improvements have been made in the treatment of hepatitis C virus (HCV) infection with the introduction of direct-acting antiviral agents (DAAs). However, despite successful viral clearance, many patients continue to have HCV-related disease progression. Therefore, new treatments must be developed to achieve viral clearance and prevent the risk of HCV-related diseases. In particular, the use of pitavastatin together with DAAs may improve the antiviral efficacy as well as decrease the progression of liver fibrosis and the incidence of HCV-related hepatocellular carcinoma. To investigate the management methods for HCV-related diseases using pitavastatin and DAAs, clinical trials should be undertaken. However, concerns have been raised about potential drug interactions between statins and DAAs. Therefore, pre-clinical trials using a replicon system, human hepatocyte-like cells, human neurons and human cardiomyocytes from human-induced pluripotent stem cells should be conducted. Based on these pre-clinical trials, an optimal direct-acting antiviral agent could be selected for combination with pitavastatin and DAAs. Following the pre-clinical trial, the combination of pitavastatin and the optimal direct-acting antiviral agent should be compared to other combinations of DAAs ( e.g., sofosbuvir and velpatasvir) according to the antiviral effect on HCV infection, HCV-related diseases and cost-effectiveness. PMID:27583130

  8. Management of hepatitis C genotype 4 in the directly acting antivirals era

    PubMed Central

    Hathorn, Emma; Elsharkawy, Ahmed M

    2016-01-01

    Genotype 4 chronic hepatitis C (G4 HCV) accounts for 13% of worldwide HCV infections; with 10 million people infected with the virus across the world. Up to the end of 2013, the only treatment option for G4 HCV was treatment with pegylated interferon and ribavirin for 24–48 weeks. Since late 2013, treatment of G4 HCV has been transformed by the licensing of many directly acting antiviral agents (DAA). It is an exciting time to be involved in the management of HCV generally and G4 particularly. Interferon-free DAA regimens are now a reality for G4 HCV. This review will highlight these developments and discuss the data behind the use of these drugs. It will also highlight future regimens that are likely to be available over the coming years. PMID:27752338

  9. Use of Direct-Acting Antivirals for the Treatment of Hepatitis C Virus-Associated Oral Lichen Planus: A Case Report.

    PubMed

    Misaka, Kenji; Kishimoto, Takashi; Kawahigashi, Yuji; Sata, Michio; Nagao, Yumiko

    2016-01-01

    Hepatitis C virus (HCV) is frequently associated with various extrahepatic manifestations such as autoimmune features and immune complex deposit diseases. Oral lichen planus (OLP) is one of the representative extrahepatic manifestations of HCV infection. Direct-acting antivirals (DAA) are highly effective and safe for the eradication of HCV. However, there is a lack of information regarding the association between HCV-associated OLP and interferon (IFN)-free DAA therapy. Herein, we present the case of a 60-year-old female who was diagnosed with OLP during routine periodontal treatment by a dentist. The patient was referred for hepatitis C treatment using IFN-free DAA, which resulted in the improvement of the symptoms of OLP. This case represents the safety and efficacy of IFN-free DAAs in patients with HCV-associated OLP. However, long-term follow-up studies are required to elucidate the therapeutic effects of this therapy in these patients.

  10. Use of Direct-Acting Antivirals for the Treatment of Hepatitis C Virus-Associated Oral Lichen Planus: A Case Report

    PubMed Central

    Misaka, Kenji; Kishimoto, Takashi; Kawahigashi, Yuji; Sata, Michio; Nagao, Yumiko

    2016-01-01

    Hepatitis C virus (HCV) is frequently associated with various extrahepatic manifestations such as autoimmune features and immune complex deposit diseases. Oral lichen planus (OLP) is one of the representative extrahepatic manifestations of HCV infection. Direct-acting antivirals (DAA) are highly effective and safe for the eradication of HCV. However, there is a lack of information regarding the association between HCV-associated OLP and interferon (IFN)-free DAA therapy. Herein, we present the case of a 60-year-old female who was diagnosed with OLP during routine periodontal treatment by a dentist. The patient was referred for hepatitis C treatment using IFN-free DAA, which resulted in the improvement of the symptoms of OLP. This case represents the safety and efficacy of IFN-free DAAs in patients with HCV-associated OLP. However, long-term follow-up studies are required to elucidate the therapeutic effects of this therapy in these patients. PMID:27920651

  11. HCV Drug Resistance Challenges in Japan: The Role of Pre-Existing Variants and Emerging Resistant Strains in Direct Acting Antiviral Therapy

    PubMed Central

    Chayama, Kazuaki; Hayes, C. Nelson

    2015-01-01

    Sustained virological response (SVR) rates have increased dramatically following the approval of direct acting antiviral (DAA) therapies. While individual DAAs have a low barrier to resistance, most patients can be successfully treated using DAA combination therapy. However, DAAs are vulnerable to drug resistance, and resistance-associated variants (RAVs) may occur naturally prior to DAA therapy or may emerge following drug exposure. While most RAVs are quickly lost in the absence of DAAs, compensatory mutations may reinforce fitness. However, the presence of RAVs does not necessarily preclude successful treatment. Although developments in hepatitis C virus (HCV) therapy in Asia have largely paralleled those in the United States, Japan’s July 2014 approval of asunaprevir plus daclatasvir combination therapy as the first all-oral interferon-free therapy was not repeated in the United States. Instead, two different combination therapies were approved: sofosbuvir/ledipasvir and paritaprevir/ritonavir/ombitasvir/dasabuvir. This divergence in treatment approaches may lead to differences in resistance challenges faced by Japan and the US. However, the recent approval of sofosbuvir plus ledipasvir in Japan and the recent submissions of petitions for approval of paritaprevir/ritonavir plus ombitasvir suggest a trend towards a new consensus on emerging DAA regimens. PMID:26473914

  12. 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

  13. Next Steps Toward Eradication of Hepatitis C in the Era of Direct Acting Antivirals

    PubMed Central

    Hesamizadeh, Khashayar; Sharafi, Heidar; Rezaee-Zavareh, Mohammad Saeid; Behnava, Bita; Alavian, Seyed Moayed

    2016-01-01

    Context After the introduction of safe and highly effective hepatitis C virus (HCV) treatments, eradication of HCV in the next 20 years is the ultimate goal. Since 2011, the advent of first generation direct acting antivirals (DAAs) were started and followed by the introduction of a new wave of DAAs in 2013 which exhibit outstanding efficacy. It is obvious that the eradication of hepatitis C is not restricted to development of DAAs. Evidence Acquisition An electronic search of available literature published was conducted in all peer-reviewed journal indexed in PubMed, Scopus and Google scholar. The literature search was done among articles related treatment of hepatitis C with DAAs in different patient groups with mass screening of the patients and cost benefit of new treatments as main key words. Results There are major steps that should be taken to eradicate HCV, including (1) the development of screening strategies, particularly for groups such as intravenous drug users and recipients of blood or blood products before the introduction of HCV screening in donors; (2) the development of strategies to overcome issues with the high cost of recently introduced treatments; (3) special attention to special patient groups, such as HIV/HCV co-infection, hemophilia, thalassemia, hemodialysis, and liver-transplant patients; and (4) development of preventive strategies, such as the development of an efficient HCV vaccine, special attention to harm reduction in high-risk groups, and promotion of mass awareness of HCV. Conclusions The eradication of HCV will require significant governmental financial investment for screening, prevention, and treatment of infected patients. Although, we have a long way to eradication of HCV, the next steps could be including proper planning to patient finding, availability of new treatments to all patients and development of HCV prevention strategies such as vaccines. PMID:27275164

  14. Memory re-differentiation and reduced lymphocyte activation in chronic HCV-infected patients receiving direct-acting antivirals.

    PubMed

    Burchill, M A; Golden-Mason, L; Wind-Rotolo, M; Rosen, H R

    2015-12-01

    Recently, the treatment of HCV has advanced significantly due to the introduction of direct-acting antivirals (DAAs). Studies using interferon (IFN)-containing regimens failed to consistently show restoration of immunologic responses. Therefore, IFN-free DAA formulations provide a unique opportunity to dissect the immunologic effect of HCV cure. This study investigates the restoration of the immune compartment as a consequence of rapid viral clearance in patients successfully treated with DAAs and in the absence of IFN and ribavirin. Here, we evaluate the immunologic changes that occurred following DAA-mediated HCV cure. Peripheral blood from nineteen previously treatment-naïve patients with chronic HCV genotype 1a/1b who received an IFN and ribavirin-free regimen of daclatasvir, asunaprevir and BMS-791325 was evaluated. Immune reconstitution occurs in patients in whom HCV was successfully eradicated via DAA therapy. Restoration of the CD4(+) T-cell compartment in the peripheral blood and a re-differentiation of the T lymphocyte memory compartment resulted in a more effector memory cell population and a reduction in expression in the co-inhibitory molecule TIGIT in bulk T lymphocytes. Furthermore, we observed a partial reversal of the exhausted phenotype in HCV-specific CD8(+) T cells and a dampening of the activation state in peripheral NK cells. Collectively, our data provide the groundwork for dissecting the effect of DAA therapy on the immune system and identifying novel mechanisms by which chronic HCV infection exerts immunosuppressive effects on T cells through the recently described co-inhibitory molecule TIGIT.

  15. The Risk of Hepatocellular Carcinoma After Directly Acting Antivirals for Hepatitis C Virus Treatment in Liver Transplanted Patients: Is It Real?

    PubMed Central

    Strazzulla, Alessio; Maria Rita Iemmolo, Rosa; Carbone, Ennio; Concetta Postorino, Maria; Mazzitelli, Maria; De Santis, Mario; Di Benedetto, Fabrizio; Maria Cristiani, Costanza; Costa, Chiara; Pisani, Vincenzo; Torti, Carlo

    2016-01-01

    Introduction Since directly acting antivirals (DAAs) for treatment of hepatitis C virus (HCV) were introduced, conflicting data emerged about the risk of hepatocellular carcinoma (HCC) after interferon (IFN)-free treatments. We present a case of recurrent, extra-hepatic HCC in a liver-transplanted patient soon after successful treatment with DAAs, along with a short review of literature. Case Presentation In 2010, a 53-year old man, affected by chronic HCV (genotype 1) infection and decompensated cirrhosis, underwent liver resection for HCC and subsequently received orthotopic liver transplantation. Then, HCV relapsed and, in 2013, he was treated with pegylated-IFN plus ribavirin; but response was null. In 2014, he was treated with daclatasvir plus simeprevir to reach sustained virological response. At baseline and at the end of HCV treatment, computed tomography (CT) scan of abdomen excluded any lesions suspected for HCC. However, alpha-fetoprotein was 2.9 ng/mL before DAAs, increasing up to 183.1 ng/mL at week-24 of follow-up after the completion of therapy. Therefore, CT scan of abdomen was performed again, showing two splenic HCC lesions. Conclusions Overall, nine studies have been published about the risk of HCC after DAAs. Patients with previous HCC should be carefully investigated to confirm complete HCC remission before starting, and proactive follow-up should be performed after DAA treatment. PMID:28070200

  16. The Australasian Hepatology Association consensus guidelines for the provision of adherence support to patients with hepatitis C on direct acting antivirals

    PubMed Central

    Richmond, Jacqueline A; Sheppard-Law, Suzanne; Mason, Susan; Warner, Sherryne L

    2016-01-01

    Background Hepatitis C is a blood-borne virus primarily spread through sharing of drug-injecting equipment. Approximately 150 million people worldwide and 230,000 Australians are living with chronic hepatitis C infection. In March 2016, the Australian government began subsidizing direct acting antivirals (DAAs) for the treatment of hepatitis C, which are highly effective (95% cure rate) and have few side effects. However, there is limited evidence to inform the provision of adherence support to people with hepatitis C on DAAs including the level of medication adherence required to achieve a cure. Methodology In February 2016, a steering committee comprising four authors convened an expert panel consisting of six hepatology nurses, a hepatologist, a pharmacist, a consumer with hepatitis C and treatment experience, and a consumer advocate. The expert panel focused on the following criteria: barriers and enablers to DAA adherence; assessment and monitoring of DAA adherence; components of a patient-centered approach to DAA adherence; patients that may require additional adherence support; and interventions to support DAA adherence. The resultant guidelines underwent three rounds of consultation with the expert panel, Australasian Hepatology Association (AHA) members (n=12), and key stakeholders (n=7) in June 2016. Feedback was considered by the steering committee and incorporated if consensus was achieved. Results Twenty-four guidelines emerged from the evidence synthesis and expert panel discussion. The guidelines focus on the pretreatment assessment and education, assessment of treatment readiness, and monitoring of medication adherence. The guidelines are embedded in a patient-centered approach which highlights that all patients are at risk of nonadherence. The guidelines recommend implementing interventions focused on identifying patients’ memory triggers and hooks; use of nonconfrontational and nonjudgmental language by health professionals; and objectively

  17. Hepatitis C virus pharmacogenomics in Latin American populations: implications in the era of direct-acting antivirals

    PubMed Central

    Trinks, Julieta; Caputo, Mariela; Hulaniuk, María L; Corach, Daniel; Flichman, Diego

    2017-01-01

    In recent years, great progress has been made in the field of new therapeutic options for hepatitis C virus (HCV) infection. The new direct-acting antiviral agents (DAAs) represent a great hope for millions of chronically infected individuals because their use may lead to excellent cure rates with fewer side effects. In Latin America, the high prevalence of HCV genotype 1 infection and the significant association of Native American ancestry with risk predictive single-nucleotide polymorphisms (SNPs) in IFNL4 and ITPA genes highlight the need to implement new treatment regimens in these populations. However, the universal accessibility to DAAs is still not a reality in the region as their high cost is one of the major, although not the only, limiting factors for their broad implementation. Therefore, under these circumstances, could the assessment of host genetic markers be a useful tool to prioritize DAA treatment until global access to these new drugs can be achieved? This review will summarize the scientific evidences and the potential implications of HCV pharmacogenomics in this rapidly evolving era of anti-HCV drug development.

  18. Experience with direct acting anti-viral agents for treating hepatitis C virus infection in renal transplant recipients.

    PubMed

    Goel, Amit; Bhadauria, Dharmendra Singh; Kaul, Anupma; Prasad, Narayan; Gupta, Amit; Sharma, Raj Kumar; Rai, Praveer; Aggarwal, Rakesh

    2017-03-27

    In recent past, direct-acting anti-viral drugs (DAAs) have become the standard of care for the treatment of hepatitis C virus (HCV) infection. However, the experience with the use of these drugs in Indian renal transplant recipients is limited. We retrospectively reviewed our experience with DAA-based treatment for HCV infection in such patients. Between April 2015 and December 2016, six adults (median age 41 [range 34-52] years, male 5; GT1 2, GT3 3, and GT4 1; including three with prior failed interferon-based treatment) had received genotype-guided, DAA-based anti-HCV treatment 1 to 158 (median 15) months after renal transplantation. Of them, four completed the planned 24-week treatment without any significant adverse event. One of them had increase in serum creatinine after 16 weeks of treatment with sofosbuvir and daclatasvir, with acute interstitial nephritis on kidney biopsy; his renal function improved on stopping the drugs. The other patient had preexisting mild renal dysfunction, which worsened after 8 weeks of sofosbuvir-ledipasvir treatment; this did not reverse on stopping treatment. All the six patients achieved undetectable HCV RNA after 4 weeks of treatment and also achieved sustained virologic response, i.e. lack of detectable HCV RNA in serum 12 weeks after stopping treatment. Overall, DAA-based treatment was effective in treating HCV infection in our renal transplant recipients; however, caution and monitoring of renal function during such treatment is advisable in patients who have additional factors that predispose to renal injury.

  19. Direct-acting antiviral treatment in adults infected with hepatitis C virus: Reactivation of hepatitis B virus coinfection as a further challenge.

    PubMed

    De Monte, Anne; Courjon, Johan; Anty, Rodolphe; Cua, Eric; Naqvi, Alissa; Mondain, Véronique; Cottalorda, Jacqueline; Ollier, Laurence; Giordanengo, Valérie

    2016-05-01

    Use of direct-acting antiviral drugs (DAAs) greatly improves management of adults infected with hepatitis C virus (HCV) whether patients are treatment-naive or unsuccessfully pre-treated. Several inhibitors of viral nonstructural proteins (NS3/4A protease, NS5A and NS5B polymerase) allow a rapid HCV clearance and increase rates of sustained virological response. Both the EASL and AASLD guidelines have recently published up-to-date recommendations for their use, addressing each HCV genotype and particular situations. However, management of patients coinfected with hepatitis B virus (HBV) has been developed by these guidelines with reference to cases of HBV reactivation reported during previous anti-HCV regimens containing interferon known active against both HBV and HCV. In the setting of the interferon-free HCV therapies with DAAs only, the possibility of HBV reactivation during treatment of hepatitis C is raised due to viral interferences in HCV/HBV coinfected persons. Herein, we report a case of early HBV reactivation during DAAs-based anti-HCV treatment (ledipasvir/sofosbuvir) in a patient having a resolved HBV infection and chronically infected with HCV genotype 4 and HIV. Moreover, we review similar recent cases of HBV reactivation in patients infected with HBV and HCV genotype 1 during treatment of hepatitis C by regimen incorporating other combination of DAAs (sofosbuvir/simeprevir or daclatasvir/asunaprevir). Due to the potential risk of early HBV reactivation in HCV/HBV-coinfected patients during interferon-free DAAs-based HCV therapies, altogether these cases highlight the necessity to closely monitor HBV coinfection, regardless its stage (chronic, occult, resolved), whatever HCV genotype or class of DAAs used.

  20. Mathematical Modeling of Hepatitis C Prevalence Reduction with Antiviral Treatment Scale-Up in Persons Who Inject Drugs in Metropolitan Chicago

    DOE PAGES

    Echevarria, Desarae; Gutfraind, Alexander; Boodram, Basmattee; ...

    2015-08-21

    New direct-acting antivirals (DAAs) provide an opportunity to combat hepatitis C virus (HCV) infection in persons who inject drugs (PWID). Here we use a mathematical model to predict the impact of a DAA-treatment scale-up on HCV prevalence among PWID and the estimated cost in metropolitan Chicago.

  1. Hepatitis C Treatment With Direct-Acting Antivirals in Kidney Transplant: Preliminary Results From a Multicenter Study.

    PubMed

    Gentil, M A; González-Corvillo, C; Perelló, M; Zarraga, S; Jiménez-Martín, C; Lauzurica, L R; Alonso, A; Franco, A; Hernández-Marrero, D; Sánchez-Fructuoso, A

    2016-11-01

    Hepatitis C (HC) is a very relevant negative prognosis factor for graft and transplant recipient survival. New direct-acting antivirals (DAAs) allow us to solve this problem in an effective way. It is crucial to understand their real impact in our daily practice. We analyzed treatment results with DAA, free of interferon, in kidney transplant recipients (KTRs) from 15 Spanish hospitals (Grupo Español de Actualización en Trasplante), regarding effectiveness, tolerance, and impact on immunosuppression, renal function-proteinuria, and diabetes. One hundred nineteen KTRs were included (9 combined liver-kidney transplants). The main DAA used was sofobusvir (91%) combined with ledipasvir (55%), simeprevir (14%), or daclatasvir (13%); in 9 cases (7%), a paritaprevir-ritonavir-ombitasvir-dasabuvir combination (3D) was used; Ribavirin was used as a coadjuvant in 18%. Side effects were limited (23.5%) and without relevance in general, except in 7 patients for whom we needed to interrupt the treatment due to neurotoxicity (1) caused by drug interaction (3D and tacrolimus) or anemia (3) by Ribavirin or others. Ninety-four patients had completed the treatment when data were analyzed: virological response was seen in 97.8% % of cases. Liver function analysis improved: 84% normal versus 21% before starting the treatment (P < .001). Renal function and proteinuria did not change. Tacrolimus level at the end of DAA-treatment was significantly lower with respect to the beginning (5.8 ± 2.1 ng/mL vs. 7.4 ± 1.8 ng/mL, P = .03), despite a slight increase in the dose (2.6 mg/d vs. 2.3 mg/d, P = .17). DAA are highly effective in the treatment of hepatitis C in KTRs with good tolerance in general, making it possible to solve the problem and have a good chance to improve the prognosis in our transplantation patients. The use of these therapies in KTRs requires special control and coordination with digestive professionals, especially if 3D or Ribavirin is used.

  2. HIV/HCV Antiviral Drug Interactions in the Era of Direct-acting Antivirals

    PubMed Central

    Rice, Donald P.; Faragon, John J.; Banks, Sarah; Chirch, Lisa M.

    2016-01-01

    Abstract Therapy for human immunodeficiency virus (HIV) and chronic hepatitis C has evolved over the past decade, resulting in better control of infection and clinical outcomes; however, drug-drug interactions remain a significant hazard. Joint recommendations from the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America regarding drug-drug interactions between HIV antiretroviral agents and direct-acting antiviral agents for treatment of hepatitis C virus (HCV) infection are reviewed here. This review is oriented to facilitate appropriate selection of an antiviral therapy regimen for HCV infection based on the choice of antiretroviral therapy being administered and, if necessary, switching antiretroviral regimens. PMID:27777891

  3. Recent Advances in Antiviral Therapy for Chronic Hepatitis C

    PubMed Central

    Tamori, Akihiro; Enomoto, Masaru; Kawada, Norifumi

    2016-01-01

    Hepatitis C virus (HCV) infection is a major worldwide health problem. Chronic infection induces continuous inflammation in the liver, progression of hepatic fibrosis, eventual cirrhosis, and possible hepatocellular carcinoma. Eradication of the virus is one of the most important treatment aims. A number of promising new direct-acting antivirals (DAAs) have been developed over the past 10 years. Due to their increased efficacy, safety, and tolerability, interferon-free oral therapies with DAAs have been approved for patients with HCV, including those with cirrhosis. This review introduces the characteristics and results of recent clinical trials of several DAAs: NS3/4A protease inhibitors, NS5A inhibitors, and NS5B inhibitors. DAA treatment failure and prognosis after DAA therapy are also discussed. PMID:27022210

  4. Detection of Occult Hepatitis C Virus Infection in Patients Who Achieved a Sustained Virologic Response to Direct-Acting Antiviral Agents for Recurrent Infection After Liver Transplantation.

    PubMed

    Elmasry, Sandra; Wadhwa, Sanya; Bang, Bo-Ram; Cook, Linda; Chopra, Shefali; Kanel, Gary; Kim, Brian; Harper, Tammy; Feng, Zongdi; Jerome, Keith R; Kahn, Jeffrey A; Saito, Takeshi

    2017-02-01

    Occult infection with hepatitis C virus (HCV) is defined as the presence of the HCV genome in either liver tissue or peripheral blood monocytes, despite constant negative results from tests for HCV RNA in serum. We investigated whether patients who maintained a sustained virologic response 12 weeks after therapy (SVR12) with direct-acting antiviral (DAA) agents for recurrent HCV infection after liver transplantation had occult HCV infections. We performed a prospective study of 134 patients with recurrent HCV infection after liver transplantation who were treated with DAAs, with or without ribavirin, from 2014 through 2016 (129 patients achieved an SVR12). In >10% of the patients who achieved SVR12 (n = 14), serum levels of aminotransferases did not normalize during or after DAA therapy, or they normalized transiently but then increased sharply after DAA therapy. Of these 14 patients, 9 were assessed for occult HCV infection by reverse transcription quantitative polymerase chain reaction. This analysis revealed that 55% of these patients (n = 5) had an occult infection, with the detection of negative strand viral genome, indicating viral replication. These findings indicate the presence of occult HCV infection in some patients with abnormal levels of serum aminotransferases, despite SVR12 to DAAs for HCV infection after liver transplantation.

  5. Hepatitis C infected patients need vitamin D3 supplementation in the era of direct acting antivirals treatment

    PubMed Central

    Kondo, Yasuteru

    2017-01-01

    It has been reported that the serum level of vitamin D3 (VitD3) could affect the natural course of chronic hepatitis C (CH-C) and the response to treatment with pegylated interferon (Peg-IFN) and ribavirin. Although several mechanisms for the favorable effects of VitD3 supplementation were reported, the total effect of VitD3 supplementation remains unclear. Previously, we reported that supplementation with 1(OH)VitD3 could enhance the Th1 response inducing not only a favorable immune response for viral eradication but also HCC control. Recently, the main treatment of CH-C should be direct acting antivirals (DAAs) without Peg-IFN. Peg-IFN is a strong immune-modulator. Therefore, an immunological analysis should be carried out to understand the effect of VitD3 after treatment of DAAs without Peg-IFN. The induction of a favorable immune response by adding VitD3 might be able to suppress the hepatocarcinogenesis after achieving SVR, especially in children and elderly patients with severe fibrosis lacking sufficient amounts of VitD3. PMID:28293078

  6. Liver stiffness predicts the response to direct-acting antiviral-based therapy against chronic hepatitis C in cirrhotic patients.

    PubMed

    Neukam, K; Morano-Amado, L E; Rivero-Juárez, A; Macías, J; Granados, R; Romero-Palacios, A; Márquez, M; Merino, D; Ortega, E; Alados-Arboledas, J C; Cucurull, J; Omar, M; Ryan-Murua, P; Pineda, J A

    2016-12-21

    The purpose of this investigation was to evaluate the impact of liver stiffness (LS) on the response to direct-acting antiviral (DAA)-based therapy against hepatitis C virus (HCV) infection in cirrhotic patients. Those patients included in two Spanish prospective cohorts of patients receiving therapy based on at least one DAA, who showed a baseline LS ≥ 12.5 kPa and who had reached the scheduled time point for sustained virological response evaluation 12 weeks after completing therapy (SVR12) were analysed. Pegylated interferon/ribavirin-based therapy plus an HCV NS3/4A protease inhibitor (PR-PI group) was administered to 198 subjects, while 146 received interferon-free regimens (IFN-free group). The numbers of patients with SVR12 according to an LS < 21 kPa versus ≥21 kPa were 59/99 (59.6%) versus 46/99 (46.5%) in the PR-PI group (p = 0.064) and 41/43 (95.3%) versus 90/103 (87.4%) in the IFN-free group (p = 0.232). Corresponding figures for the relapse rates in those who presented end-of-treatment response (ETR) were 3/62 (4.8%) versus 10/56 (17.9%, p = 0.024) and 1/42 (2.4%) versus 8/98 (8.2%, p = 0.278), respectively. In a multivariate analysis adjusted for age, sex and use of interferon, a baseline LS ≥ 21 kPa was identified as an independent predictor of relapse [adjusted odds ratio, AOR (95% confidence interval, CI): 4.228 (1.344-13.306); p = 0.014] in those patients with ETR. LS above 21 kPa is associated with higher rates of relapse to DAA-based therapy in HCV-infected patients with cirrhosis in clinical practice. LS could help us to tailor the duration and composition of DAA-based combinations in cirrhotic subjects, in order to minimise the likelihood of relapse.

  7. Hepatitis C virus treatment for prevention among people who inject drugs: Modeling treatment scale-up in the age of direct-acting antivirals

    PubMed Central

    Martin, Natasha K; Vickerman, Peter; Grebely, Jason; Hellard, Margaret; Hutchinson, Sharon J; Lima, Viviane D; Foster, Graham R; Dillon, John F; Goldberg, David J; Dore, Gregory J; Hickman, Matthew

    2013-01-01

    Substantial reductions in hepatitis C virus (HCV) prevalence among people who inject drugs (PWID) cannot be achieved by harm reduction interventions such as needle exchange and opiate substitution therapy (OST) alone. Current HCV treatment is arduous and uptake is low, but new highly effective and tolerable interferon-free direct-acting antiviral (DAA) treatments could facilitate increased uptake. We projected the potential impact of DAA treatments on PWID HCV prevalence in three settings. A dynamic HCV transmission model was parameterized to three chronic HCV prevalence settings: Edinburgh, UK (25%); Melbourne, Australia (50%); and Vancouver, Canada (65%). Using realistic scenarios of future DAAs (90% sustained viral response, 12 weeks duration, available 2015), we projected the treatment rates required to reduce chronic HCV prevalence by half or three-quarters within 15 years. Current HCV treatment rates may have a minimal impact on prevalence in Melbourne and Vancouver (<2% relative reductions) but could reduce prevalence by 26% in 15 years in Edinburgh. Prevalence could halve within 15 years with treatment scale-up to 15, 40, or 76 per 1,000 PWID annually in Edinburgh, Melbourne, or Vancouver, respectively (2-, 13-, and 15-fold increases, respectively). Scale-up to 22, 54, or 98 per 1,000 PWID annually could reduce prevalence by three-quarters within 15 years. Less impact occurs with delayed scale-up, higher baseline prevalence, or shorter average injecting duration. Results are insensitive to risk heterogeneity or restricting treatment to PWID on OST. At existing HCV drug costs, halving chronic prevalence would require annual treatment budgets of US $3.2 million in Edinburgh and approximately $50 million in Melbourne and Vancouver. Conclusion: Interferon-free DAAs could enable increased HCV treatment uptake among PWID, which could have a major preventative impact. However, treatment costs may limit scale-up, and should be addressed. (Hepatology 2013;58:1598

  8. Antiretroviral Use in the CEASE Cohort Study and Implications for Direct-Acting Antiviral Therapy in Human Immunodeficiency Virus/Hepatitis C Virus Coinfection

    PubMed Central

    Martinello, Marianne; Dore, Gregory J.; Skurowski, Jasmine; Bopage, Rohan I.; Finlayson, Robert; Baker, David; Bloch, Mark; Matthews, Gail V.

    2016-01-01

    Background. Interferon-free direct-acting antiviral (DAA) regimens for hepatitis C virus (HCV) provide a major advance in clinical management, including in human immunodeficiency virus (HIV)/HCV coinfection. Drug-drug interactions (DDIs) with combination antiretroviral therapy (cART) require consideration. This study aimed to characterize the cART regimens in HIV/HCV-coinfected individuals and assess the clinical significance of DDIs with DAAs in a real-world cohort. Methods. This analysis included participants enrolled in CEASE-D, a prospective cohort of HIV/HCV-coinfected individuals in Sydney, Australia, between July 2014 and December 2015. A simulation of potential DDIs between participants' cART and interferon-free DAA regimens was performed using www.hep-druginteractions.org and relevant prescribing information. Results. In individuals on cART with HCV genotype (GT) 1 and 4 (n = 128), category 3 DDIs (contraindicated or not recommended) were noted in 0% with sofosbuvir/ledipasvir, 0% with sofosbuvir plus daclatasvir, 17% with sofosbuvir/velpatasvir, 36% with ombitasvir/paritaprevir/ritonavir ± dasabuvir, 51% with grazoprevir/elbasvir, and 51% with sofosbuvir plus simeprevir; current cART regimens were suitable for coadministration in 100%, 100%, 73%, 64%, 49%, and 49%, respectively. In individuals with HCV GT 2 or 3 (n = 53), category 3 DDIs were evident in 0% with sofosbuvir plus daclatasvir, 0% with sofosbuvir and ribavirin, and 13% with sofosbuvir/velpatasvir; current cART regimens were suitable in 100%, 100%, and 81%, respectively. Conclusions. Potential DDIs are expected and will impact on DAA prescribing in HIV/HCV coinfection. Sofosbuvir in combination with an NS5A inhibitor or ribavirin appeared to be the most suitable regimens in this cohort. Evaluation of potential DDIs is required to prevent adverse events or treatment failure. PMID:27419177

  9. Geno2pheno[HCV] – A Web-based Interpretation System to Support Hepatitis C Treatment Decisions in the Era of Direct-Acting Antiviral Agents

    PubMed Central

    Kalaghatgi, Prabhav; Sikorski, Anna Maria; Knops, Elena; Rupp, Daniel; Sierra, Saleta; Heger, Eva; Neumann-Fraune, Maria; Beggel, Bastian; Walker, Andreas; Timm, Jörg; Walter, Hauke; Obermeier, Martin; Kaiser, Rolf; Bartenschlager, Ralf; Lengauer, Thomas

    2016-01-01

    The face of hepatitis C virus (HCV) therapy is changing dramatically. Direct-acting antiviral agents (DAAs) specifically targeting HCV proteins have been developed and entered clinical practice in 2011. However, despite high sustained viral response (SVR) rates of more than 90%, a fraction of patients do not eliminate the virus and in these cases treatment failure has been associated with the selection of drug resistance mutations (RAMs). RAMs may be prevalent prior to the start of treatment, or can be selected under therapy, and furthermore they can persist after cessation of treatment. Additionally, certain DAAs have been approved only for distinct HCV genotypes and may even have subtype specificity. Thus, sequence analysis before start of therapy is instrumental for managing DAA-based treatment strategies. We have created the interpretation system geno2pheno[HCV] (g2p[HCV]) to analyse HCV sequence data with respect to viral subtype and to predict drug resistance. Extensive reviewing and weighting of literature related to HCV drug resistance was performed to create a comprehensive list of drug resistance rules for inhibitors of the HCV protease in non-structural protein 3 (NS3-protease: Boceprevir, Paritaprevir, Simeprevir, Asunaprevir, Grazoprevir and Telaprevir), the NS5A replicase factor (Daclatasvir, Ledipasvir, Elbasvir and Ombitasvir), and the NS5B RNA-dependent RNA polymerase (Dasabuvir and Sofosbuvir). Upon submission of up to eight sequences, g2p[HCV] aligns the input sequences, identifies the genomic region(s), predicts the HCV geno- and subtypes, and generates for each DAA a drug resistance prediction report. g2p[HCV] offers easy-to-use and fast subtype and resistance analysis of HCV sequences, is continuously updated and freely accessible under http://hcv.geno2pheno.org/index.php. The system was partially validated with respect to the NS3-protease inhibitors Boceprevir, Telaprevir and Simeprevir by using data generated with recombinant, phenotypic

  10. Geno2pheno[HCV] - A Web-based Interpretation System to Support Hepatitis C Treatment Decisions in the Era of Direct-Acting Antiviral Agents.

    PubMed

    Kalaghatgi, Prabhav; Sikorski, Anna Maria; Knops, Elena; Rupp, Daniel; Sierra, Saleta; Heger, Eva; Neumann-Fraune, Maria; Beggel, Bastian; Walker, Andreas; Timm, Jörg; Walter, Hauke; Obermeier, Martin; Kaiser, Rolf; Bartenschlager, Ralf; Lengauer, Thomas

    2016-01-01

    The face of hepatitis C virus (HCV) therapy is changing dramatically. Direct-acting antiviral agents (DAAs) specifically targeting HCV proteins have been developed and entered clinical practice in 2011. However, despite high sustained viral response (SVR) rates of more than 90%, a fraction of patients do not eliminate the virus and in these cases treatment failure has been associated with the selection of drug resistance mutations (RAMs). RAMs may be prevalent prior to the start of treatment, or can be selected under therapy, and furthermore they can persist after cessation of treatment. Additionally, certain DAAs have been approved only for distinct HCV genotypes and may even have subtype specificity. Thus, sequence analysis before start of therapy is instrumental for managing DAA-based treatment strategies. We have created the interpretation system geno2pheno[HCV] (g2p[HCV]) to analyse HCV sequence data with respect to viral subtype and to predict drug resistance. Extensive reviewing and weighting of literature related to HCV drug resistance was performed to create a comprehensive list of drug resistance rules for inhibitors of the HCV protease in non-structural protein 3 (NS3-protease: Boceprevir, Paritaprevir, Simeprevir, Asunaprevir, Grazoprevir and Telaprevir), the NS5A replicase factor (Daclatasvir, Ledipasvir, Elbasvir and Ombitasvir), and the NS5B RNA-dependent RNA polymerase (Dasabuvir and Sofosbuvir). Upon submission of up to eight sequences, g2p[HCV] aligns the input sequences, identifies the genomic region(s), predicts the HCV geno- and subtypes, and generates for each DAA a drug resistance prediction report. g2p[HCV] offers easy-to-use and fast subtype and resistance analysis of HCV sequences, is continuously updated and freely accessible under http://hcv.geno2pheno.org/index.php. The system was partially validated with respect to the NS3-protease inhibitors Boceprevir, Telaprevir and Simeprevir by using data generated with recombinant, phenotypic

  11. Early Results of Pilot Study Using Hepatitis C Virus (HCV) Positive Kidneys to Transplant HCV Infected Patients with End-Stage Renal Disease Allowing for Successful Interferon-Free Direct Acting Antiviral Therapy after Transplantation

    PubMed Central

    Gallegos-Orozco, Juan F; Kim, Robin; Thiesset, Heather F; Hatch, Jenny; Lynch, Keisa; Chaly, Jr, Thomas; Shihab, Fuad; Ahmed, Faris; Hall, Isaac

    2016-01-01

    Introduction: Hepatitis C virus (HCV) infection in kidney transplant (KTX) patients reduces long-term patient and graft survival. Direct-acting antivirals (DAA) are > 90% effective in achieving sustained viral response (SVR); however, DAAs are not routinely available to patients with end-stage renal disease (ESRD). The University of Utah Transplant Program developed a protocol to allow HCV-positive potential KTX recipients to accept HCV-positive donors' kidneys. Three months after successful KTX, they were eligible for DAA therapy. Methods: HCV-positive patients approved for KTX by the University of Utah Transplant Selection Committee were eligible to be enrolled in this study. Patients consented for the use of HCV-positive donor organs. Three to six months after successful KTX, these patients were treated for HCV with interferon-free direct-acting antiviral regimens according to viral genotype and prior treatment experience. Results: Between 2014-2015, 12 HCV-positive patients were listed for KTX. Eight patients were kidney only eligible, seven patients received HCV-positive deceased donor kidneys, and one received an HCV-negative organ. Currently, six patients have completed treatment, all have achieved sustained viral response (SVR), and one patient is currently awaiting treatment. All seven patients have functioning kidney grafts. Wait time for KTX was reduced amongst all blood groups from an average of 1,350 days to only 65 days. Conclusions: HCV-positive patients with ESRD can successfully receive an HCV-positive donor's kidney. Once transplanted, these patients can receive DAA therapy and achieve SVR. Use of HCV-positive organs reduced time on the waitlist by greater than three years and expanded the donor organ pool. PMID:28018760

  12. Second-generation direct-acting-antiviral hepatitis C virus treatment: Efficacy, safety, and predictors of SVR12

    PubMed Central

    Werner, Christoph R; Schwarz, Julia M; Egetemeyr, Daniel P; Beck, Robert; Malek, Nisar P; Lauer, Ulrich M; Berg, Christoph P

    2016-01-01

    AIM To gather data on the antiviral efficacy and safety of second generation direct acting antiviral (DAA) treatment with respect to sustained virological response (SVR) 12 wk after conclusion of treatment, and to determine predictors of SVR12 in this setting. METHODS Two hundred and sixty patients treated with SOF combination partners PR (n = 51), R (n = 10), SMV (n = 30), DCV (n = 81), LDV (n = 73), or 3D (n = 15). 144/260 were pre-treated, 89/260 had liver cirrhosis, 56/260 had portal hypertension with platelets < 100/nL, 25/260 had a MELD score ≥ 10 and 17/260 were post-liver transplantation patients. 194/260 had HCV GT1, 44/260 HCV GT3. RESULTS Two hundred and forty/256 (93.7%) patients achieved SVR12 (mITT); 4/260 were lost to follow-up. SVR12 rates for subgroups were: 92% for SOF/DCV, 93% for each SOF/SMV, SOF/PR, 94% for SOF/LDV, 100% for 3D, 94% for pretreated, 87% for liver cirrhosis, 82% for patients with platelets < 100/nL, 88% post-liver transplantation, 95% for GT1a, 93% for GT1b, 90% for GT3, 100% for GT2, 4, and 6. 12 patients suffered from relapse, 6 prematurely discontinued treatment, of which 4 died. Negative predictors of SVR12 were a platelet count < 100/nL, MELD score ≥ 10 (P < 0.0001), liver cirrhosis (P = 0.005) at baseline. In Interferon-free treatment GT3 had significantly lower SVR rates than GT1 (P = 0.016). Side effects were mild. CONCLUSION Excellent SVR12 rates and the favorable side-effect profile of DAA-combination therapy can be well translated into “real-world”. Patients with advanced liver disease, signs of portal hypertension, especially with platelets < 100/nL and patients with GT3 are in special need for further research efforts to overcome comparatively higher rates of virological failure. PMID:27672299

  13. Evolution of multi-drug resistant HCV clones from pre-existing resistant-associated variants during direct-acting antiviral therapy determined by third-generation sequencing

    PubMed Central

    Takeda, Haruhiko; Ueda, Yoshihide; Inuzuka, Tadashi; Yamashita, Yukitaka; Osaki, Yukio; Nasu, Akihiro; Umeda, Makoto; Takemura, Ryo; Seno, Hiroshi; Sekine, Akihiro; Marusawa, Hiroyuki

    2017-01-01

    Resistance-associated variant (RAV) is one of the most significant clinical challenges in treating HCV-infected patients with direct-acting antivirals (DAAs). We investigated the viral dynamics in patients receiving DAAs using third-generation sequencing technology. Among 283 patients with genotype-1b HCV receiving daclatasvir + asunaprevir (DCV/ASV), 32 (11.3%) failed to achieve sustained virological response (SVR). Conventional ultra-deep sequencing of HCV genome was performed in 104 patients (32 non-SVR, 72 SVR), and detected representative RAVs in all non-SVR patients at baseline, including Y93H in 28 (87.5%). Long contiguous sequences spanning NS3 to NS5A regions of each viral clone in 12 sera from 6 representative non-SVR patients were determined by third-generation sequencing, and showed the concurrent presence of several synonymous mutations linked to resistance-associated substitutions in a subpopulation of pre-existing RAVs and dominant isolates at treatment failure. Phylogenetic analyses revealed close genetic distances between pre-existing RAVs and dominant RAVs at treatment failure. In addition, multiple drug-resistant mutations developed on pre-existing RAVs after DCV/ASV in all non-SVR cases. In conclusion, multi-drug resistant viral clones at treatment failure certainly originated from a subpopulation of pre-existing RAVs in HCV-infected patients. Those RAVs were selected for and became dominant with the acquisition of multiple resistance-associated substitutions under DAA treatment pressure. PMID:28361915

  14. PEGylated recombinant human interferon-ω as a long-acting antiviral agent: structure, antiviral activity and pharmacokinetics.

    PubMed

    Yu, Weili; Yu, Changming; Wu, Ling; Fang, Ting; Qiu, Rui; Zhang, Jinlong; Yu, Ting; Fu, Ling; Chen, Wei; Hu, Tao

    2014-08-01

    Recombinant human interferon-ω (rhIFN-ω) exhibits a potent antiviral activity. Because of poor pharmacokinetics (PK) of rhIFN-ω, frequent dosing of rhIFN-ω is necessitated to achieve the sustained antiviral efficacy. PEGylation can efficiently improve the PK of rhIFN-ω while substantially decrease its bioactivity. The structure, antiviral activity and PK of the PEGylated rhIFN-ω were measured to establish their relationship with PEGylation sites, polyethylene glycol (PEG) mass and PEG structure. Accordingly, N-terminus and the lysine residues were selected as the PEGylation sites. PEGs with Mw of 20kDa and 40kDa were used to investigate the effect of PEG mass. Linear and branched PEGs were used to investigate the effect of PEG structure. PEGylation decreased the antiviral activity of rhIFN-ω and improved its PK. The PEGylation sites determine the bioactivity of the PEGylated rhIFN-ω and the conjugated PEG mass determines the PK. N-terminally PEGylated rhIFN-ω with 40kDa linear PEG maintains 21.7% of the rhIFN-ω antiviral activity with a half-life of 139.6h. Thus, N-terminally PEGylated rhIFN-ω with linear 40kDa PEG is a potential antiviral agent for long-acting treatment of the viral diseases.

  15. Detection of Natural Resistance-Associated Substitutions by Ion Semiconductor Technology in HCV1b Positive, Direct-Acting Antiviral Agents-Naïve Patients

    PubMed Central

    Marascio, Nadia; Pavia, Grazia; Strazzulla, Alessio; Dierckx, Tim; Cuypers, Lize; Vrancken, Bram; Barreca, Giorgio Settimo; Mirante, Teresa; Malanga, Donatella; Oliveira, Duarte Mendes; Vandamme, Anne-Mieke; Torti, Carlo; Liberto, Maria Carla; Focà, Alfredo

    2016-01-01

    Naturally occurring resistance-associated substitutions (RASs) can negatively impact the response to direct-acting antivirals (DAAs) agents-based therapies for hepatitis C virus (HCV) infection. Herein, we set out to characterize the RASs in the HCV1b genome from serum samples of DAA-naïve patients in the context of the SINERGIE (South Italian Network for Rational Guidelines and International Epidemiology, 2014) project. We deep-sequenced the NS3/4A protease region of the viral population using the Ion Torrent Personal Genome Machine, and patient-specific majority rule consensus sequence summaries were constructed with a combination of freely available next generation sequencing data analysis software. We detected NS3/4A protease major and minor variants associated with resistance to boceprevir (V36L), telaprevir (V36L, I132V), simeprevir (V36L), and grazoprevir (V36L, V170I). Furthermore, we sequenced part of HCV NS5B polymerase using Sanger-sequencing and detected a natural RAS for dasabuvir (C316N). This mutation could be important for treatment strategies in cases of previous therapy failure. PMID:27618896

  16. Detection of Natural Resistance-Associated Substitutions by Ion Semiconductor Technology in HCV1b Positive, Direct-Acting Antiviral Agents-Naïve Patients.

    PubMed

    Marascio, Nadia; Pavia, Grazia; Strazzulla, Alessio; Dierckx, Tim; Cuypers, Lize; Vrancken, Bram; Barreca, Giorgio Settimo; Mirante, Teresa; Malanga, Donatella; Oliveira, Duarte Mendes; Vandamme, Anne-Mieke; Torti, Carlo; Liberto, Maria Carla; Focà, Alfredo; The Sinergie-Umg Study Group

    2016-08-27

    Naturally occurring resistance-associated substitutions (RASs) can negatively impact the response to direct-acting antivirals (DAAs) agents-based therapies for hepatitis C virus (HCV) infection. Herein, we set out to characterize the RASs in the HCV1b genome from serum samples of DAA-naïve patients in the context of the SINERGIE (South Italian Network for Rational Guidelines and International Epidemiology, 2014) project. We deep-sequenced the NS3/4A protease region of the viral population using the Ion Torrent Personal Genome Machine, and patient-specific majority rule consensus sequence summaries were constructed with a combination of freely available next generation sequencing data analysis software. We detected NS3/4A protease major and minor variants associated with resistance to boceprevir (V36L), telaprevir (V36L, I132V), simeprevir (V36L), and grazoprevir (V36L, V170I). Furthermore, we sequenced part of HCV NS5B polymerase using Sanger-sequencing and detected a natural RAS for dasabuvir (C316N). This mutation could be important for treatment strategies in cases of previous therapy failure.

  17. Hepatitis C Viral Kinetics in the Era of Direct Acting Antiviral Agents and IL28B

    PubMed Central

    Dahari, Harel; Guedj, Jeremie; Perelson, Alan S.; Layden, Thomas J.

    2011-01-01

    In the last decade hepatitis C virus (HCV) kinetics has become an important clinical tool for the optimization of therapy with (pegylated)-interferon-α (IFN) and ribavirin (RBV). Mathematical models have generated important insights into HCV pathogenesis, HCV- host dynamics, and IFN and RBV’s modes of action. Clinical trials with direct acting agents (DAAs) against various steps of the HCV life cycle have revealed new viral kinetic patterns that have not been observed with IFN±RBV. Very recently, studies have showed that single nucleotide polymorphisms (SNPs) in the IL28B gene region were associated with race/ethnicity and with response to IFN±RBV. Here we review our current knowledge of HCV kinetics and related mathematical models during IFN±RBV and/or DAA based therapies, HCV pathogenesis, and the role of IL28B polymorphism on early HCV kinetics. Better understanding of the mode of actions of drug(s) and viral kinetics may help to develop, in the near future, new individualized therapeutic regimens that include DAAs in combination with IFN+RBV. PMID:22180724

  18. Barriers to treatment of failed or interferon ineligible patients in the era of DAA: single center study

    PubMed Central

    Seo, Kwang Il; Yun, Byung Chul; Li, Weiquan James; Lee, Sang Uk; Han, Byung Hoon; Park, Eun Taek

    2017-01-01

    Background/Aims Interferon-based treatment is not appropriate for a large number of patients with chronic hepatitis C for various medical and social reasons. Newly developed directly acting antivirals (DAAs) have been used to treat chronic hepatitis C without severe adverse effects and have achieved a sustained viral response (SVR) rate of 80-90% with short treatment duration. We were interested to determine whether all patients who failed to respond to or were ineligible for interferon-based therapy could be treated with DAAs. Methods Medical records of patients with positive serum anti-hepatitis C virus (HCV) or HCV RNA between January 2009 and December 2013 were reviewed. Demographic, clinical, and treatment data were collected for analysis. Results A total of 876 patients were positive for both anti-HCV and HCV RNA. Of these, 244 patients were eligible for interferon, although this was associated with relapse in 39 (16%) of patients. In total, 130 patients stopped interferon therapy (67% adverse effects, 28% non-adherent, 4% malignancy, 1% alcohol abuse) and 502 patients were ineligible (66% medical contraindications, 25% non-adherent, 5% socioeconomic problems). Among 671 patients who were ineligible for or failed to respond to interferon therapy, more than 186 (27.7%) could not be treated with DAA due to financial, social, or cancer-related conditions. Conclusions Newly developed DAAs are a promising treatment for patients with chronic hepatitis C who are ineligible for or failed to respond to interferon-based therapy. Nevertheless, not all chronic hepatitis C patients can be treated with DAAs due to various reasons. PMID:28259115

  19. DAAs Rapidly Reduce Inflammation but Increase Serum VEGF Level: A Rationale for Tumor Risk during Anti-HCV Treatment

    PubMed Central

    Villani, Rosanna; Facciorusso, Antonio; Bellanti, Francesco; Tamborra, Rosanna; Piscazzi, Annamaria; Landriscina, Matteo; Vendemiale, Gianluigi; Serviddio, Gaetano

    2016-01-01

    Background Novel direct-acting antivirals (DAAs) have completely changed the panorama of hepatitis C due to their high efficacy and optimal safety profile. Unfortunately, an unexpectedly high rate of early recurrence of hepatocellular carcinoma has been reported within weeks of starting treatment, but the mechanism is not known. Methods We monitored the serum level of vascular endothelial growth factor (VEGF) and changes in the pattern of circulating interleukins in 103 chronic hepatitis C patients during antiviral treatment with DAA-regimens. VEGF, epidermal growth factor (EGF), and several interleukins were assessed at baseline, during treatment, and after treatment. The biological effect of DAA-treated patient serum on human umbilical vein endothelial cell (HUVEC) proliferation was also confirmed. Results After 4 weeks of therapy, VEGF increased approximately 4-fold compared to baseline, remained elevated up to the end of treatment, and returned to the pre-treatment level after the end of therapy. In contrast, interleukin-10 and tumor necrosis factor-alpha significantly decreased during therapy, which was coincident with HCV clearance. The levels of both remained low after treatment. The addition of serum from patients collected during therapy induced HUVEC proliferation; however, this disappeared after the end of therapy. Conclusions DAA administration induces an early increase in serum VEGF and a change in the inflammatory pattern, coinciding with HCV clearance. This may alter the balance between inflammatory and anti-inflammatory processes and modify the antitumor surveillance of the host. Fortunately, such modifications return reverse to normal after the end of treatment. PMID:27997563

  20. Can Hepatitis C Virus (HCV) Direct-Acting Antiviral Treatment as Prevention Reverse the HCV Epidemic Among Men Who Have Sex With Men in the United Kingdom? Epidemiological and Modeling Insights

    PubMed Central

    Martin, Natasha K.; Thornton, Alicia; Hickman, Matthew; Sabin, Caroline; Nelson, Mark; Cooke, Graham S.; Martin, Thomas C. S.; Delpech, Valerie; Ruf, Murad; Price, Huw; Azad, Yusef; Thomson, Emma C.; Vickerman, Peter

    2016-01-01

    Background. We report on the hepatitis C virus (HCV) epidemic among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) in the United Kingdom and model its trajectory with or without scaled-up HCV direct-acting antivirals (DAAs). Methods. A dynamic HCV transmission model among HIV–diagnosed MSM in the United Kingdom was calibrated to HCV prevalence (antibody [Ab] or RNA positive), incidence, and treatment from 2004 to 2011 among HIV-diagnosed MSM in the UK Collaborative HIV Cohort (UK CHIC). The epidemic was projected with current or scaled-up HCV treatment, with or without a 20% behavioral risk reduction. Results. HCV prevalence among HIV-positive MSM in UK CHIC increased from 7.3% in 2004 to 9.9% in 2011, whereas primary incidence was flat (1.02–1.38 per 100 person-years). Over the next decade, modeling suggests 94% of infections are attributable to high-risk individuals, comprising 7% of the population. Without treatment, HCV chronic prevalence could have been 38% higher in 2015 (11.9% vs 8.6%). With current treatment and sustained virological response rates (status quo), chronic prevalence is likely to increase to 11% by 2025, but stabilize with DAA introduction in 2015. With DAA scale-up to 80% within 1 year of diagnosis (regardless of disease stage), and 20% per year thereafter, chronic prevalence could decline by 71% (to 3.2%) compared to status quo in 2025. With additional behavioral interventions, chronic prevalence could decline further to <2.5% by 2025. Conclusions. Epidemiological data and modeling suggest a continuing HCV epidemic among HIV-diagnosed MSM in the United Kingdom driven by high-risk individuals, despite high treatment rates. Substantial reductions in HCV transmission could be achieved through scale-up of DAAs and moderately effective behavioral interventions. PMID:26908813

  1. Real-world experience with interferon-free, direct acting antiviral therapies in Asian Americans with chronic hepatitis C and advanced liver disease

    PubMed Central

    Chang, Christine Y.; Nguyen, Pauline; Le, An; Zhao, Changqing; Ahmed, Aijaz; Daugherty, Tami; Garcia, Gabriel; Lutchman, Glen; Kumari, Radhika; Nguyen, Mindie H.

    2017-01-01

    Abstract Real-life data on interferon (IFN)-free direct acting antiviral (DAA) therapies for chronic hepatitis C (CHC) is limited for Asian Americans. To evaluate sustained virologic response (SVR) and adverse events (AE) in Asian Americans treated with sofosbuvir (SOF)-based, IFN-free DAA therapies. This is a retrospective study of 110 consecutive Asian Americans with HCV genotypes 1 to 3 or 6 treated with IFN-free SOF-based regimens for 8 to 24 weeks between February 2014 and March 2016 at a university center in Northern California. Mean age was 63 ± 12 years, mean BMI was 25 ± 6 (kg/m2), and about half (52%) were male. Most patients were infected with HCV genotype 1 (HCV-1, 64%), followed by HCV-2 (14%), HCV-6 (13%), and HCV-3 (8%). Half had cirrhosis, and the majority of these (67%) had decompensation. Overall SVR12 was 93% (102/110), and highest among patients without cirrhosis, liver transplant, or HCC (100%, 37/37). SVR12 was lower among patients with HCC (82%, 14/17), decompensated cirrhosis (84%, 31/37), or liver transplant (89%, 17/19), regardless of treatment and genotype. Most common AEs were anemia (25%), fatigue (20%), and headache (12%). Anemia was highest in patients receiving SOF/RBV (67%). There was 1 treatment-unrelated serious adverse effect (SAE). There were 7 dose reductions due to anemia or fatigue from RBV and 2 treatment discontinuations due to fatigue or loss of insurance authorization. This real-life cohort of Asian American CHC patients treated with IFN-free SOF-based therapies showed high overall treatment response and good tolerability, despite very high rates of advanced disease and prior treatment failure. PMID:28178174

  2. Baseline quasispecies selection and novel mutations contribute to emerging resistance-associated substitutions in hepatitis C virus after direct-acting antiviral treatment

    PubMed Central

    Kai, Yugo; Hikita, Hayato; Morishita, Naoki; Murai, Kazuhiro; Nakabori, Tasuku; Iio, Sadaharu; Hagiwara, Hideki; Imai, Yasuharu; Tamura, Shinji; Tsutsui, Syusaku; Naito, Masafumi; Nishiuchi, Meiko; Kondo, Yasuteru; Kato, Takanobu; Suemizu, Hiroshi; Yamada, Ryoko; Oze, Tsugiko; Yakushijin, Takayuki; Hiramatsu, Naoki; Sakamori, Ryotaro; Tatsumi, Tomohide; Takehara, Tetsuo

    2017-01-01

    Resistance-associated substitutions (RASs) in hepatitis C virus (HCV) appear upon failure of treatment with direct-acting antivirals (DAAs). However, their origin has not been clarified in detail. Among 11 HCV genotype 1b patients who experienced virologic failure with asunaprevir (ASV)/daclatasvir (DCV), 10 had major NS5A L31M/V-Y93H variants after treatment. L31M/V-Y93H variants were detected as a minor clone before therapy in 6 patients and were the most closely related to the post-treatment variants by phylogenetic tree analysis in 4 patients. Next, to consider the involvement of a trace amount of pre-existing variants below the detection limit, we analysed human hepatocyte chimeric mice infected with DAA-naïve patient serum. L31V-Y93H variants emerged after treatment with ledipasvir (LDV)/GS-558093 (nucleotide NS5B inhibitor) and decreased under the detection limit, but these variants were dissimilar to the L31V-Y93H variants reappearing after ASV/DCV re-treatment. Finally, to develop an infection derived from a single HCV clone, we intrahepatically injected full-genome HCV RNA (engineered based on the wild-type genotype 1b sequence) into chimeric mice. A new Y93H mutation actually occurred in this model after LDV monotherapy failure. In conclusion, post-treatment RASs appear by 2 mechanisms: the selection of pre-existing substitutions among quasispecies and the generation of novel mutations during therapy. PMID:28134353

  3. Demonstration Advanced Avionics System (DAAS) function description

    NASA Technical Reports Server (NTRS)

    Bailey, A. J.; Bailey, D. G.; Gaabo, R. J.; Lahn, T. G.; Larson, J. C.; Peterson, E. M.; Schuck, J. W.; Rodgers, D. L.; Wroblewski, K. A.

    1982-01-01

    The Demonstration Advanced Avionics System, DAAS, is an integrated avionics system utilizing microprocessor technologies, data busing, and shared displays for demonstrating the potential of these technologies in improving the safety and utility of general aviation operations in the late 1980's and beyond. Major hardware elements of the DAAS include a functionally distributed microcomputer complex, an integrated data control center, an electronic horizontal situation indicator, and a radio adaptor unit. All processing and display resources are interconnected by an IEEE-488 bus in order to enhance the overall system effectiveness, reliability, modularity and maintainability. A detail description of the DAAS architecture, the DAAS hardware, and the DAAS functions is presented. The system is designed for installation and flight test in a NASA Cessna 402-B aircraft.

  4. Direct Acting Antivirals in Patients with Chronic Hepatitis C and Down Syndrome

    PubMed Central

    Perumpail, Ryan B.; Cholankeril, George

    2016-01-01

    Patients with Down syndrome who received blood transfusions, likely in conjunction with cardiothoracic surgery for congenital heart disease and prior to the implementation of blood-donor screening for hepatitis C virus infection, face a substantial risk of acquiring the infection. In the past, interferon-based therapy for chronic hepatitis C infection in patients with Down syndrome was noted to have lower efficacy and potentially higher risk of adverse effects. Recently, the treatment for chronic hepatitis C has been revolutionized with the introduction of interferon-free direct acting antivirals with favorable safety, tolerability, and efficacy profile. Based on our experiences, the newly approved sofosbuvir-based direct acting antiviral therapy is well tolerated and highly efficacious in this subpopulation of hepatitis C virus infected patients with Down syndrome. PMID:27847658

  5. Demonstration Advanced Avionics System (DAAS), Phase 1

    NASA Technical Reports Server (NTRS)

    Bailey, A. J.; Bailey, D. G.; Gaabo, R. J.; Lahn, T. G.; Larson, J. C.; Peterson, E. M.; Schuck, J. W.; Rodgers, D. L.; Wroblewski, K. A.

    1981-01-01

    Demonstration advanced anionics system (DAAS) function description, hardware description, operational evaluation, and failure mode and effects analysis (FMEA) are provided. Projected advanced avionics system (PAAS) description, reliability analysis, cost analysis, maintainability analysis, and modularity analysis are discussed.

  6. Combined Treatment with Antiviral Therapy and Rituximab in Patients with Mixed Cryoglobulinemia: Review of the Literature and Report of a Case Using Direct Antiviral Agents-Based Antihepatitis C Virus Therapy

    PubMed Central

    Urraro, Teresa; Gragnani, Laura; Piluso, Alessia; Fabbrizzi, Alessio; Monti, Monica; Boldrini, Barbara; Ranieri, Jessica; Zignego, Anna Linda

    2015-01-01

    Mixed cryoglobulinemia (MC) is an autoimmune/B-cell lymphoproliferative disorder associated with Hepatitis C Virus (HCV) infection, manifesting as a systemic vasculitis. In the last decade, antiviral treatment (AT) with pegylated interferon (Peg-IFN) plus ribavirin (RBV) was considered the first therapeutic option for HCV-MC. In MC patients ineligible or not responsive to antivirals, the anti-CD20 monoclonal antibody rituximab (RTX) is effective. A combined AT plus RTX was also suggested. Since the introduction of direct acting antivirals (DAAs), few data were published about MC and no data about a combined schedule. Here, we report a complete remission of MC after a sustained virological response following a combined RTX/Peg-IFN+RBV+DAA (boceprevir) treatment and review the literature about the combined RTX/AT. PMID:25815218

  7. Future mobile access for open-data platforms and the BBC-DaaS system

    NASA Astrophysics Data System (ADS)

    Edlich, Stefan; Singh, Sonam; Pfennigstorf, Ingo

    2013-03-01

    In this paper, we develop an open data platform on multimedia devices to act as marketplace of data for information seekers and data providers. We explore the important aspects of Data-as-a-Service (DaaS) service in the cloud with a mobile access point. The basis of the DaaS service is to act as a marketplace for information, utilizing new technologies and recent new scalable polyglot architectures based on NoSql databases. Whereas Open-Data platforms are beginning to be widely accepted, its mobile use is not. We compare similar products, their approach and a possible mobile usage. We discuss several approaches to address the mobile access as a native app, html5 and a mobile first approach together with the several frontend presentation techniques. Big data visualization itself is in the early days and we explore some possibilities to get big data / open data accessed by mobile users.

  8. Prevention of allograft HCV recurrence with peri-transplant human monoclonal antibody MBL-HCV1 combined with a single oral direct-acting antiviral: A proof-of-concept study.

    PubMed

    Smith, H L; Chung, R T; Mantry, P; Chapman, W; Curry, M P; Schiano, T D; Boucher, E; Cheslock, P; Wang, Y; Molrine, D C

    2017-03-01

    Patients with active hepatitis C virus (HCV) infection at transplantation experience rapid allograft infection, increased risk of graft failure and accelerated fibrosis. MBL-HCV1, a neutralizing human monoclonal antibody (mAb) targeting the HCV envelope, was combined with a licensed oral direct-acting antiviral (DAA) to prevent HCV recurrence post-transplant in an open-label exploratory efficacy trial. Eight subjects received MBL-HCV1 beginning on the day of transplant with telaprevir initiated between days 3 and 7 post-transplantation. Following FDA approval of sofosbuvir, two subjects received MBL-HCV1 starting on the day of transplant with sofosbuvir initiated on day 3. Combination treatment was administered for 8-12 weeks or until the stopping rule for viral rebound was met. The primary endpoint was undetectable HCV RNA at day 56 with exploratory endpoints of sustained virologic response (SVR) at 12 and 24 weeks post-treatment. Both subjects receiving mAb and sofosbuvir achieved SVR24. Four of eight subjects in the mAb and telaprevir group met the primary endpoint; one subject achieved SVR24 and three subjects relapsed 2-12 weeks post-treatment. The other four subjects experienced viral breakthrough. There were no serious adverse events related to study treatment. This proof-of-concept study demonstrates that peri-transplant immunoprophylaxis combined with a single oral direct-acting antiviral in the immediate post-transplant period can prevent HCV recurrence.

  9. Multi-scale model for hepatitis C viral load kinetics under treatment with direct acting antivirals.

    PubMed

    Clausznitzer, Diana; Harnisch, Julia; Kaderali, Lars

    2016-06-15

    Hepatitis C virus (HCV) infections are a global health problem, and extensive research over the last decades has been targeted at understanding its molecular biology and developing effective antiviral treatments. Recently, a number of potent direct acting antiviral drugs have been developed targeting specific processes in the viral life cycle. Here, we developed a mathematical multi-scale model of the within-host dynamics of HCV infection by integrating a standard model for viral infection with a detailed model of the viral replication cycle inside infected cells. We use this model to study patient time courses of viral load under treatment with daclatasvir, an inhibitor of the viral non-structural protein NS5A. Model analysis predicts that treatment efficacy can be increased by combining daclatasvir with dedicated viral polymerase inhibitors, corresponding to promising current strategies in drug development. Hence, our model presents a predictive tool for in silico simulations, which can be used to study and optimize direct acting antiviral drug treatment.

  10. Drug–drug interactions during antiviral therapy for chronic hepatitis C

    PubMed Central

    Kiser, Jennifer J.; Burton, James R.; Everson, Gregory T.

    2015-01-01

    The emergence of direct-acting antiviral agents (DAAs) for HCV infection represents a major advance in treatment. The NS3 protease inhibitors, boceprevir and telaprevir, were the first DAAs to receive regulatory approval. When combined with PEG-IFN and ribavirin, these agents increase rates of sustained virologic response in HCV genotype 1 to ~70%. However, this treatment regimen is associated with several toxicities. In addition, both boceprevir and telaprevir are substrates for and inhibitors of the drug transporter P-glycoprotein and the cytochrome P450 enzyme 3A4 and are, therefore, prone to clinically relevant drug interactions. Several new DAAs for HCV are in late stages of clinical development and are likely to be approved in the near future. These include the protease inhibitors, simeprevir and faldaprevir, the NS5A inhibitor, daclatasvir, and the nucleotide polymerase inhibitor, sofosbuvir. Herein, we review the clinical pharmacology and drug interactions of boceprevir, telaprevir and these investigational DAAs. Although boceprevir and telaprevir are involved in many interactions, these interactions are manageable if health-care providers proactively identify and adjust treatments. Emerging DAAs seem to have a reduced potential for drug interactions, which will facilitate their use in the treatment of HCV. PMID:23817323

  11. 78 FR 63218 - Draft Guidance for Industry on Chronic Hepatitis C Virus Infection: Developing Direct-Acting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Chronic Hepatitis C Virus... availability of a draft guidance for industry entitled ``Chronic Hepatitis C Virus Infection: Developing Direct... of development of direct-acting antiviral (DAA) drugs for the treatment of chronic hepatitis C....

  12. Analysis of UAS DAA Alerting in Fast-Time Simulations without DAA Mitigation

    NASA Technical Reports Server (NTRS)

    Thipphavong, David P.; Santiago, Confesor; Isaacson, Douglas R.; Lee, Seung Man; Park, Chunki; Refai, Mohamad Said; Snow, James

    2015-01-01

    Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of performance standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements for DAA alerting system performance. A recent study conducted using NASA's ACES (Airspace Concept Evaluation System) simulation capability begins to address questions surrounding the development of draft MOPS for DAA alerting systems. ACES simulations were conducted to study the performance of alerting systems proposed by the SC-228 DAA Alerting sub-group. Analysis included but was not limited to: 1) correct alert (and timeliness), 2) false alert (and severity and duration), 3) missed alert, and 4) probability of an alert type at the time of loss of well clear. The performance of DAA alerting systems when using intent vs. dead-reckoning for UAS ownship trajectories was also compared. The results will be used by SC-228 to inform decisions about the surveillance standards of UAS DAA systems and future requirements development and validation efforts.

  13. Management of direct antiviral agent failures

    PubMed Central

    Buti, María; Esteban, Rafael

    2016-01-01

    The current standard of care for patients with chronic hepatitis C virus (HCV) infection is a combination of direct-acting antiviral agents (DAAs). Most HCV patients treated with these drugs achieve viral elimination, but 1% to 15% fail to attain this objective. Treatment failures are usually related to relapse, and less often to on-treatment viral breakthrough. HCV drug resistant associated substitutions are detected in most patients who do not eliminate the virus. The risk of developing these variants depends on host- and virus-related factors, the properties of the drugs used, and the treatment strategies applied. Patients who carry Resistant Associated Substitutions (RASs) may not obtain benefits from treatment, and are at a risk of disease progression. Whether HCV RASs persist depends on their type: NS3-4A variants often disappear gradually after DAA therapy is stopped, whereas NS5A variants tend to persist for more than 2 years. The best way to prevent emergence of resistant variants is to eliminate the virus at the first treatment using highly potent DAAs with genetic barriers to resistance. For those who fail an NS5A inhibitor, deferral of treatment is recommended pending the availability of additional data if they do not have cirrhosis or reasons for urgent re-treatment. If re-treatment is needed, the most commonly used strategy is sofosbuvir as backbone therapy plus a drug from a class other than that previously used, for 24 weeks. Unless it is contraindicated, weight-based ribavirin should also be added. If available, nucleotide-based (eg, sofosbuvir) triple or quadruple DAA regimens may be considered. The optimal treatment for patients who fail an NS5A inhibitor and those with multidrug-resistant variants remains to be defined, and research efforts should continue to focus on treatment for these patients. PMID:28081594

  14. Frequency of Natural Resistance within NS5a Replication Complex Domain in Hepatitis C Genotypes 1a, 1b: Possible Implication of Subtype-Specific Resistance Selection in Multiple Direct Acting Antivirals Drugs Combination Treatment

    PubMed Central

    Bagaglio, Sabrina; Andolina, Andrea; Merli, Marco; Uberti-Foppa, Caterina; Morsica, Giulia

    2016-01-01

    Different HCV subtypes may naturally harbor different resistance selection to anti-NS5a inhibitors. 2761 sequences retrieved from the Los Alamos HCV database were analyzed in the NS5a domain 1, the target of NS5a inhibitors. The NS5a resistance-associated polymorphisms (RAPs) were more frequently detected in HCV G1b compared to G1a. The prevalence of polymorphisms associated with cross-resistance to compounds in clinical use (daclatasvir, DCV, ledipasvir, LDV, ombitasvir, and OMV) or scheduled to come into clinical use in the near future (IDX719, elbasvir, and ELV) was higher in G1b compared to G1a (37/1552 (2.4%) in 1b sequences and 15/1209 (1.2%) in 1a isolates, p = 0.040). Interestingly, on the basis of the genotype-specific resistance pattern, 95 (6.1%) G1b sequences had L31M RAP to DCV/IDX719, while 6 sequences of G1a (0.5%) harbored L31M RAP, conferring resistance to DCV/LDV/IDX719/ELV (p < 0.0001). Finally, 28 (2.3%) G1a and none of G1b isolates harbored M28V RAP to OMV (p < 0.0001). In conclusion, the pattern of subtype-specific resistance selection in the naturally occurring strains may guide the treatment option in association with direct acting antivirals (DAAs) targeting different regions, particularly in patients that are difficult to cure, such as those with advanced liver disease or individuals who have failed previous DAAs. PMID:27023593

  15. SC-228 Inclusion of DAA Warning Alert for TCAS Interoperability

    NASA Technical Reports Server (NTRS)

    Fern, Lisa

    2016-01-01

    alerting system is to provide critical timing information to the pilot about the potential for a loss of well clear with another aircraft. This is done by employing both temporal and spatial thresholds that indicate to the pilot the likelihood and imminence of a loss of well clear. The design of the DAA alerting thresholds is a balancing act between eliciting the desired pilot response in real loss of well clear threat events and reducing excessive, unnecessary, and/or uncoordinated UAS maneuvering within the air traffic environment; larger thresholds, both spatially and temporally, may increase the likelihood of a pilot avoiding a loss of well clear, but it can also increase the frequency of maneuvering - especially in cases where a maneuver is not actually needed to maintain well clear. A series of human in the loop (HITL) simulations have been conducted as part of NASA's Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. The purpose of these HITLs has been to provide empirical results in order to inform development of the minimum human-machine interface requirements for the DAA system. This white paper will present those results which provide evidence of a human performance benefit (in terms of response times and ability to remain well clear of other aircraft) of the DAA warning alert both with and without a collision avoidance system on board the aircraft.

  16. Analysis of UAS DAA Surveillance in Fast-Time Simulations without DAA Mitigation

    NASA Technical Reports Server (NTRS)

    Thipphavong, David P.; Santiago, Confesor; Isaacson, David R.; Lee, Seung Man; Refai, Mohamad Said; Snow, James William

    2015-01-01

    Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of performance standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements for DAA surveillance system performance. A recent study conducted using NASA's ACES (Airspace Concept Evaluation System) simulation capability begins to address questions surrounding the development of draft MOPS for DAA surveillance systems. ACES simulations were conducted to study the performance of sensor systems proposed by the SC-228 DAA Surveillance sub-group. Analysis included but was not limited to: 1) number of intruders (both IFR and VFR) detected by all sensors as a function of UAS flight time, 2) number of intruders (both IFR and VFR) detected by radar alone as a function of UAS flight time, and 3) number of VFR intruders detected by all sensors as a function of UAS flight time. The results will be used by SC-228 to inform decisions about the surveillance standards of UAS DAA systems and future requirements development and validation efforts.

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

    PubMed

    Pawlotsky, Jean-Michel

    2012-01-01

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

  18. Biomedical Mutation Analysis (BMA): A software tool for analyzing mutations associated with antiviral resistance

    PubMed Central

    Salvatierra, Karina; Florez, Hector

    2016-01-01

    Introduction: Hepatitis C virus (HCV) is considered a major public health problem, with 200 million people infected worldwide. The treatment for HCV chronic infection with pegylated interferon alpha plus ribavirin inhibitors is unspecific; consequently, the treatment is effective in only 50% of patients infected. This has prompted the development of direct-acting antivirals (DAA) that target virus proteins. These DAA have demonstrated a potent effect in vitro and in vivo; however, virus mutations associated with the development of resistance have been described. Objective: To design and develop an online information system for detecting mutations in amino acids known to be implicated in resistance to DAA. Materials and methods:    We have used computer applications, technological tools, standard languages, infrastructure systems and algorithms, to analyze positions associated with resistance to DAA for the NS3, NS5A, and NS5B genes of HCV. Results: We have designed and developed an online information system named Biomedical Mutation Analysis (BMA), which allows users to calculate changes in nucleotide and amino acid sequences for each selected sequence from conventional Sanger and cloning sequencing using a graphical interface. Conclusion: BMA quickly, easily and effectively analyzes mutations, including complete documentation and examples. Furthermore, the development of different visualization techniques allows proper interpretation and understanding of the results. The data obtained using BMA will be useful for the assessment and surveillance of HCV resistance to new antivirals, and for the treatment regimens by selecting those DAA to which the virus is not resistant, avoiding unnecessary treatment failures. The software is available at: http://bma.itiud.org. PMID:27547378

  19. Future of liver disease in the era of direct acting antivirals for the treatment of hepatitis C

    PubMed Central

    Ponziani, Francesca Romana; Mangiola, Francesca; Binda, Cecilia; Zocco, Maria Assunta; Siciliano, Massimo; Grieco, Antonio; Rapaccini, Gian Lodovico; Pompili, Maurizio; Gasbarrini, Antonio

    2017-01-01

    Hepatitis C virus (HCV) infection has been a global health problem for decades, due to the high number of infected people and to the lack of effective and well-tolerated therapies. In the last 3 years, the approval of new direct acting antivirals characterized by high rates of virological clearance and excellent tolerability has dramatically improved HCV infection curability, especially for patients with advanced liver disease and for liver transplant recipients. Long-term data about the impact of the new direct acting antivirals on liver fibrosis and liver disease-related outcomes are not yet available, due to their recent introduction. However, previously published data deriving from the use of pegylated-interferon and ribavirin lead to hypothesizing that we are going to observe, in the future, a reduction in mortality and in the incidence of hepatocellular carcinoma, as well as a regression of fibrosis for people previously affected by hepatitis C. In the liver transplant setting, clinical improvement has already been described after treatment with the new direct acting antivirals, which has often led to patients delisting. In the future, this may hopefully reduce the gap between liver organ request and availability, probably expanding liver transplant indications to other clinical conditions. Therefore, these new drugs are going to change the natural history of HCV-related liver disease and the epidemiology of HCV infection worldwide. However, the global consequences will depend on treatment accessibility and on the number of countries that could afford the use of the new direct acting antivirals. PMID:28321272

  20. Antiviral Therapy

    PubMed Central

    Stalder, Hans

    1977-01-01

    The current status of antiviral therapy is reviewed, including discussion of older approaches together with more recently developed chemotherapy. Following the introduction dealing with pathophysiological aspects of virus disease, the different approaches to antiviral therapy are presented. The reasons for the slow progress in antiviral therapy are discussed. These include: 1. the necessity of intracellular penetration of drugs acting on viral replication; 2. the severe toxicity of most antiviral drugs; 3. the narrow antiviral spectrum of most of these agents; 4. the difficulty of making a rapid etiological diagnosis in view of the necessity of starting (specific?) treatment early in the course of the disease; 5. the difficult evaluation of beneficial as compared with deleterious effects of antiviral therapy. After a detailed review of clinically tested substances, including immunoglobulins, synthetic antiviral drugs (amantadine, nucleoside analogs, thiosemicarbazones and photodynamic dyes) and interferon, a guide concerning indications and application of specific antiviral therapy is presented. Although at present there are few indications, clinicians should be aware of the (present and future) possibilities of antiviral therapy. PMID:341538

  1. Restrictions for reimbursement of direct-acting antiviral treatment for hepatitis C virus infection in Canada: a descriptive study

    PubMed Central

    Marshall, Alison D.; Saeed, Sahar; Barrett, Lisa; Cooper, Curtis L.; Treloar, Carla; Bruneau, Julie; Feld, Jordan J.; Gallagher, Lesley; Klein, Marina B.; Krajden, Mel; Shoukry, Naglaa H.; Taylor, Lynn E.; Grebely, Jason

    2016-01-01

    Background: In Canada, interferon-free, direct-acting antiviral hepatitis C virus (HCV) regimens are costly. This presents challenges for universal drug coverage of the estimated 220 000 people with chronic HCV infection nationwide. The study objective was to appraise criteria for reimbursement of 4 HCV direct-acting antivirals in Canada. Methods: We reviewed the reimbursement criteria for simeprevir, sofosbuvir, ledipasvir-sofosbuvir and paritaprevir-ritonavir-ombitasvir plus dasabuvir in the 10 provinces and 3 territories. Data were extracted from April 2015 to June 2016. The primary outcomes extracted from health ministerial websites were: 1) minimum fibrosis stage required, 2) drug and alcohol use restrictions, 3) HIV coinfection restrictions and 4) prescriber type restrictions. Results: Overall, 85%-92% of provinces/territories limited access to patients with moderate fibrosis (Meta-Analysis of Histologic Data in Viral Hepatitis stage F2 or greater, or equivalent). There were no drug and alcohol use restrictions; however, several criteria (e.g., active injection drug use) were left to the discretion of the physician. Quebec did not reimburse simeprevir and sofosbuvir for people coinfected with HIV; no restrictions were found in the remaining jurisdictions. Prescriber type was restricted to specialists in up to 42% of provinces/territories. Interpretation: This review of criteria of reimbursement of HCV direct-acting antivirals in Canada showed substantial interjurisdictional heterogeneity. The findings could inform health policy and support the development and adoption of a national HCV strategy. PMID:28018873

  2. Treatment of hepatitis C virus genotype 3 infection with direct-acting antiviral agents

    PubMed Central

    Zanaga, L.P.; Miotto, N.; Mendes, L.C.; Stucchi, R.S.B.; Vigani, A.G.

    2016-01-01

    Hepatitis C virus (HCV) genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of direct-acting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR) rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN), sofosbuvir (SOF), daclatasvir (DCV) and ribavirin (RBV). Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83–100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contraindications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82–96% among patients without cirrhosis and 62–92% among those with cirrhosis. Finally, SOF plus DCV provides 94–97% SVR rates in non-cirrhotic patients, but 59–69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection. PMID:27783808

  3. Metabolic syndrome in chronic hepatitis C infection: does it still matter in the era of directly acting antiviral therapy?

    PubMed Central

    Lim, TR

    2014-01-01

    Metabolic syndrome is prevalent in patients with hepatitis C virus (HCV) infection. Given the pandemic spread of HCV infection and metabolic syndrome, the burden of their interaction is a major public health issue. The presence of metabolic syndrome accelerates the progression of liver disease in patients with HCV infection. New drug development in HCV has seen an unprecedented rise in the last year, which resulted in better efficacy, better tolerance, and a shorter treatment duration. This review describes the underlying mechanisms and clinical effects of metabolic syndrome in HCV infection, as well as their importance in the era of new directly acting antiviral therapy. PMID:25506251

  4. Drug-Drug Interaction between the Direct-Acting Antiviral Regimen of Ombitasvir-Paritaprevir-Ritonavir plus Dasabuvir and the HIV Antiretroviral Agent Dolutegravir or Abacavir plus Lamivudine.

    PubMed

    Khatri, Amit; Trinh, Roger; Zhao, Weihan; Podsadecki, Thomas; Menon, Rajeev

    2016-10-01

    The direct-acting antiviral regimen of 25 mg ombitasvir-150 mg paritaprevir-100 mg ritonavir once daily (QD) plus 250 mg dasabuvir twice daily (BID) is approved for the treatment of hepatitis C virus genotype 1 infection, including patients coinfected with human immunodeficiency virus. This study was performed to evaluate the pharmacokinetic, safety, and tolerability effects of coadministering the regimen of 3 direct-acting antivirals with two antiretroviral therapies (dolutegravir or abacavir plus lamivudine). Healthy volunteers (n = 24) enrolled in this phase I, single-center, open-label, multiple-dose study received 50 mg dolutegravir QD for 7 days or 300 mg abacavir plus 300 mg lamivudine QD for 4 days, the 3-direct-acting-antiviral regimen for 14 days, followed by the 3-direct-acting-antiviral regimen with dolutegravir or abacavir plus lamivudine for 10 days. Pharmacokinetic parameters were calculated to compare combination therapy with 3-direct-acting-antiviral or antiretroviral therapy alone, and safety/tolerability were assessed throughout the study. Coadministration of the 3-direct-acting-antiviral regimen increased the geometric mean maximum plasma concentration (Cmax) and the area under the curve (AUC) of dolutegravir by 22% (central value ratio [90% confidence intervals], 1.219 [1.153, 1.288]) and 38% (1.380 [1.295, 1.469]), respectively. Abacavir geometric mean Cmax and AUC values decreased by 13% (0.873 [0.777, 0.979]) and 6% (0.943 [0.901, 0.986]), while those for lamivudine decreased by 22% (0.778 [0.719, 0.842]) and 12% (0.876 [0.821, 0.934]). For the 3-direct-acting-antiviral regimen, geometric mean Cmax and AUC during coadministration were within 18% of measurements made during administration of the 3-direct-acting-antiviral regimen alone, although trough concentrations for paritaprevir were 34% (0.664 [0.585, 0.754]) and 27% (0.729 [0.627, 0.847]) lower with dolutegravir and abacavir-lamivudine, respectively. All study treatments were generally

  5. Defining the Collision Avoidance Region for DAA Systems

    NASA Technical Reports Server (NTRS)

    Thipphavong, David; Cone, Andrew; Park, Chunki; Lee, Seung Man; Santiago, Confesor

    2016-01-01

    Unmanned aircraft systems (UAS) will be required to equip with a detect-­-and-­-avoid (DAA) system in order to satisfy the federal aviation regulations to maintain well clear of other aircraft, some of which may be equipped with a Traffic Collision Avoidance System (TCAS) to mitigate the possibility of mid-­-air collisions. As such, the minimum operational performance standards (MOPS) for UAS DAA systems are being designed with TCAS interoperability in mind by a group of industry, government, and academic institutions named RTCA Special Committee-228 (SC-228). This document will discuss the development of the spatial-­-temporal volume known as the collision avoidance region in which the DAA system is not allowed to provide vertical guidance to maintain or regain DAA well clear that could conflict with resolution advisories (RAs) issued by the intruder aircraft's TCAS system. Three collision avoidance region definition candidates were developed based on the existing TCAS RA and DAA alerting definitions. They were evaluated against each other in terms of their interoperability with TCAS RAs and DAA alerts in an unmitigated factorial encounter analysis of 1.3 million simulated pairs.

  6. Antiviral therapies for chronic hepatitis C virus infection with cirrhosis.

    PubMed

    Nakamoto, Shingo; Kanda, Tatsuo; Shirasawa, Hiroshi; Yokosuka, Osamu

    2015-05-18

    Patients who are infected with hepatitis C virus (HCV) and also have advanced fibrosis or cirrhosis have been recognized as "difficult-to-treat" patients during an era when peginterferon and ribavirin combination therapy is the standard of care. Recent guidelines have clearly stated that treatment should be prioritized in this population to prevent complications such as decompensation and hepatocellular carcinoma. Recent advances in the treatment of chronic hepatitis C have been achieved through the development of direct-acting antiviral agents (DAAs). Boceprevir and telaprevir are first-generation DAAs that inhibit the HCV NS3/4A protease. Boceprevir or telaprevir, in combination with peginterferon and ribavirin, improved the sustained virological response rates compared with peginterferon and ribavirin alone and were tolerated in patients with HCV genotype 1 infection without cirrhosis or compensated cirrhosis. However, the efficacy is lower especially in prior non-responders with or without cirrhosis. Furthermore, a high incidence of adverse events was observed in patients with advanced liver disease, including cirrhosis, in real-life settings. Current guidelines in the United States and in some European countries no longer recommend these regimens for the treatment of HCV. Next-generation DAAs include second-generation HCV NS3/4A protease inhibitors, HCV NS5A inhibitors and HCV NS5B inhibitors, which have a high efficacy and a lower toxicity. These drugs are used in interferon-free or in interferon-based regimens with or without ribavirin in combination with different classes of DAAs. Interferon-based regimens, such as simeprevir in combination with peginterferon and ribavirin, are well tolerated and are highly effective especially in treatment-naïve patients and in patients who received treatment but who relapsed. The efficacy is less pronounced in null-responders and in patients with cirrhosis. Interferon-free regimens in combination with ribavirin and

  7. Pre-Existing HCV Variants Resistant to DAAs and Their Sensitivity to PegIFN/RBV in Chinese HCV Genotype 1b Patients

    PubMed Central

    Zhang, Yu; Cao, Ying; Zhang, Renwen; Zhang, Xiaxia; Lu, Haiying; Wu, Chihong; Huo, Na; Xu, Xiaoyuan

    2016-01-01

    Background The efficacy of direct-acting antiviral agents (DAAs) could be attenuated by the presence of resistance-associated variants (RAVs). The aim of this study was to investigate the natural prevalence of RAVs among Chinese HCV genotype 1b patients and analyze the efficacy of pegylated interferon (PegIFN)/ribavirin (RBV) therapy in patients with and without RAVs at baseline. Methods Direct sequencing of the HCV NS3, NS5A and NS5B regions was performed in baseline serum samples of 117 DAAs-naïve subjects infected with HCV genotype 1b. The efficacy of PegIFN/RBV therapy in patients with and without RAVs at baseline was analyzed by comparing the response rates between patients with RAVs and patients with wild type virus. Results The incidence of RAVs was 8.00% (8/100) in the NS3 region (T54S, n = 1, 1.00%; R117H, n = 5, 5.00%; S122T, n = 1, 1.00%; S174F, n = 1, 1.00%), 29.91% (32/107) in the NS5A region (L28M, n = 12, 11.21%; R30Q, n = 10, 9.35%; L31M, n = 1, 0.93%; P58S, n = 4, 3.74%; Y93H, n = 8, 7.48%) and 98.15% (106/108) in the NS5B region (L159F, n = 1, 0.93%; C316N, n = 103, 95.37%; A421V, n = 6, 5.56%). The response rates to PegIFN/RBV treatment did not differ between patients with or without RAVs in the NS5A region. Conclusions Pre-existing RAVs, including key RAVs, were detected in Chinese DAAs-naïve patients infected with HCV genotype 1b. IFN-based therapy could be a good option for patients with RAVs, especially key RAVs, at baseline. PMID:27812165

  8. Chronic Hepatitis C Virus Infection: A Review of Current Direct-Acting Antiviral Treatment Strategies

    PubMed Central

    Zhang, Johnathan; Nguyen, Douglas; Hu, Ke-Qin

    2016-01-01

    Chronic Hepatitis C virus (HCV) infection carries a significant clinical burden in the United States, affecting more than 4.6 million Americans. Untreated chronic HCV infection can result in cirrhosis, portal hypertension, and hepatocellular carcinoma. Previous interferon based treatment carried low rates of success and significant adverse effects. The advent of new generation oral antiviral therapy has led to major improvements in efficacy and tolerability but has also resulted in an explosion of data with increased treatment choice complexity. Treatment guidelines are constantly evolving due to emerging regimens and real world treatment data. There also still remain subpopulations for whom current treatments are lacking or unclearly defined. Thus, the race for development of HCV treatment regimens still continues. This review of the current literature will discuss the current recommended treatment strategies and briefly overview next generation agents. PMID:27293521

  9. Multiscale Modeling of Influenza A Virus Infection Supports the Development of Direct-Acting Antivirals

    PubMed Central

    Heldt, Frank S.; Frensing, Timo; Pflugmacher, Antje; Gröpler, Robin; Peschel, Britta; Reichl, Udo

    2013-01-01

    Influenza A viruses are respiratory pathogens that cause seasonal epidemics with up to 500,000 deaths each year. Yet there are currently only two classes of antivirals licensed for treatment and drug-resistant strains are on the rise. A major challenge for the discovery of new anti-influenza agents is the identification of drug targets that efficiently interfere with viral replication. To support this step, we developed a multiscale model of influenza A virus infection which comprises both the intracellular level where the virus synthesizes its proteins, replicates its genome, and assembles new virions and the extracellular level where it spreads to new host cells. This integrated modeling approach recapitulates a wide range of experimental data across both scales including the time course of all three viral RNA species inside an infected cell and the infection dynamics in a cell population. It also allowed us to systematically study how interfering with specific steps of the viral life cycle affects virus production. We find that inhibitors of viral transcription, replication, protein synthesis, nuclear export, and assembly/release are most effective in decreasing virus titers whereas targeting virus entry primarily delays infection. In addition, our results suggest that for some antivirals therapy success strongly depends on the lifespan of infected cells and, thus, on the dynamics of virus-induced apoptosis or the host's immune response. Hence, the proposed model provides a systems-level understanding of influenza A virus infection and therapy as well as an ideal platform to include further levels of complexity toward a comprehensive description of infectious diseases. PMID:24278009

  10. New direct-acting antivirals in hepatitis C therapy: a review of sofosbuvir, ledipasvir, daclatasvir, simeprevir, paritaprevir, ombitasvir and dasabuvir.

    PubMed

    McConachie, Sean M; Wilhelm, Sheila M; Kale-Pradhan, Pramodini B

    2016-01-01

    Hepatitis C is a chronic infection associated with considerable morbidity and mortality. In recent years, there has been a shift in treatment paradigm with the discovery and approval of agents that target specific proteins vital for hepatitis C replication. The NS3/4A inhibitors simeprevir and paritaprevir, the NS5A inhibitors ombitasvir, ledipasvir, and daclatasvir, and the NS5B inhibitors sofosbuvir and dasabuvir have been newly FDA approved and incorporated as first-line agents into the latest IDSA-AASLD guidelines for Hepatitis C treatment. Used in combination, these agents produce higher rates of sustained virologic response and less adverse effects than historical options, along with limited rates of resistance. Pertinent clinical data, pharmacology, and pharmacokinetics are reviewed for these new direct acting antiviral agents.

  11. Arbidol as a broad-spectrum antiviral: an update.

    PubMed

    Blaising, Julie; Polyak, Stephen J; Pécheur, Eve-Isabelle

    2014-07-01

    Arbidol (ARB) is a Russian-made small indole-derivative molecule, licensed in Russia and China for prophylaxis and treatment of influenza and other respiratory viral infections. It also demonstrates inhibitory activity against other viruses, enveloped or not, responsible for emerging or globally prevalent infectious diseases such as hepatitis B and C, gastroenteritis, hemorrhagic fevers or encephalitis. In this review, we will explore the possibility and pertinence of ARB as a broad-spectrum antiviral, after a careful examination of its physico-chemical properties, pharmacokinetics, toxicity, and molecular mechanisms of action. Recent studies suggest that ARB's dual interactions with membranes and aromatic amino acids in proteins may be central to its broad-spectrum antiviral activity. This could impact on the virus itself, and/or on cellular functions or critical steps in virus-cell interactions, thereby positioning ARB as both a direct-acting antiviral (DAA) and a host-targeting agent (HTA). In the context of recent studies in animals and humans, we will discuss the prospective clinical use of ARB in various viral infections.

  12. Hepatitis C Virus and Natural Compounds: a New Antiviral Approach?

    PubMed Central

    Calland, Noémie; Dubuisson, Jean; Rouillé, Yves; Séron, Karin

    2012-01-01

    Hepatitis C is a major global health burden with an estimated 160 million infected individuals worldwide. This long-term disease evolves slowly, often leading to chronicity and potentially to liver failure. There is no anti-HCV vaccine, and, until recently, the only treatment available, based on pegylated interferon and ribavirin, was partially effective, and had considerable side effects. With recent advances in the understanding of the HCV life cycle, the development of promising direct acting antivirals (DAAs) has been achieved. Their use in combination with the current treatment has led to encouraging results for HCV genotype 1 patients. However, this therapy is quite expensive and will probably not be accessible for all patients worldwide. For this reason, constant efforts are being made to identify new antiviral molecules. Recent reports about natural compounds highlight their antiviral activity against HCV. Here, we aim to review the natural molecules that interfere with the HCV life cycle and discuss their potential use in HCV therapy. PMID:23202460

  13. Antiviral therapy of hepatitis C as curative treatment of indolent B-cell lymphoma

    PubMed Central

    Merli, Michele; Carli, Giuseppe; Arcaini, Luca; Visco, Carlo

    2016-01-01

    The association of hepatitis C virus (HCV) and B-cell non-Hodgkin lymphomas (NHL) has been highlighted by several epidemiological and biological insights; however the most convincing evidence is represented by interventional studies demonstrating the capability of antiviral treatment (AT) with interferon (IFN) with or without ribavirin to induce the regression of indolent lymphomas, especially of marginal-zone origin. In the largest published retrospective study (100 patients) the overall response rate (ORR) after first-line IFN-based AT was 77% (44% complete responses) and responses were sustainable (median duration of response 33 mo). These results were confirmed by a recent meta-analysis on 254 patients, demonstrating an ORR of 73%. Moreover this analysis confirmed the highly significant correlation between the achievement of viral eradication sustained virological response (SVR) and hematological responses. Two large prospective studies demonstrated that AT is associated with improved survival and argue in favor of current guidelines’ recommendation of AT as preferential first-line option in asymptomatic patients with HCV-associated indolent NHL. The recently approved direct-acting antiviral agents (DAAs) revolutionized the treatment of HCV infection, leading to SVR approaching 100% in all genotypes. Very preliminary data of IFN-free DAAs therapy in indolent HCV-positive NHL seem to confirm their activity in inducing lymphoma regression. PMID:27784957

  14. Assorted Processing of Synthetic Trans-Acting siRNAs and Its Activity in Antiviral Resistance.

    PubMed

    Zhao, Mingmin; San León, David; Mesel, Frida; García, Juan Antonio; Simón-Mateo, Carmen

    2015-01-01

    The use of syn-tasiRNAs has been proposed as an RNA interference technique alternative to those previously described: hairpin based, virus induced gene silencing or artificial miRNAs. In this study we engineered the TAS1c locus to impair Plum pox virus (PPV) infection by replacing the five native siRNAs with two 210-bp fragments from the CP and the 3´NCR regions of the PPV genome. Deep sequencing analysis of the small RNA species produced by both constructs in planta has shown that phased processing of the syn-tasiRNAs is construct-specific. While in syn-tasiR-CP construct the processing was as predicted 21-nt phased in register with miR173-guided cleavage, the processing of syn-tasiR-3NCR is far from what was expected. A 22-nt species from the miR173-guided cleavage was a guide of two series of phased small RNAs, one of them in an exact 21-nt register, and the other one in a mixed of 21-/22-nt frame. In addition, both constructs produced abundant PPV-derived small RNAs in the absence of miR173 as a consequence of a strong sense post-transcriptional gene silencing induction. The antiviral effect of both constructs was also evaluated in the presence or absence of miR173 and showed that the impairment of PPV infection was not significantly higher when miR173 was present. The results show that syn-tasiRNAs processing depends on construct-specific factors that should be further studied before the so-called MIGS (miRNA-induced gene silencing) technology can be used reliably.

  15. Adenosine Deaminases Acting on RNA (ADARs) are both Antiviral and Proviral Dependent upon the Virus

    PubMed Central

    Samuel, Charles E.

    2010-01-01

    A-to-I RNA editing, the deamination of adenosine (A) to inosine (I) that occurs in regions of RNA with double-stranded character, is catalyzed by a family of Adenosine Deaminases Acting on RNA (ADARs). In mammals there are three ADAR genes. Two encode proteins that possess demonstrated deaminase activity: ADAR1, which is interferon-inducible, and ADAR2 which is constitutively expressed. ADAR3, by contrast, has not yet been shown to bean active enzyme. The specificity of the ADAR1 and ADAR2 deaminases ranges from highly site-selective to non-selective, dependent on the duplex structure of the substrate RNA. A-to-I editing is a form of nucleotide substitution editing, because I is decoded as guanosine (G) instead of A by ribosomes during translation and by polymerases during RNA-dependent RNA replication. Additionally, A-to-I editing can alter RNA structure stability as I:U mismatches are less stable than A:U base pairs. Both viral and cellular RNAs are edited by ADARs. A-to-I editing is of broad physiologic significance. Among the outcomes of A-to-I editing are biochemical changes that affect how viruses interact with their hosts, changes that can lead to either enhanced or reduced virus growth and persistence dependent upon the specific virus. PMID:21211811

  16. New direct-acting antivirals for patients with chronic HCV infection: can we monitor treatment using an HCV core antigen assay?

    PubMed

    Alonso, R; Pérez-García, F; Ampuero, D; Reigadas, E; Bouza, E

    2017-03-01

    We evaluated the diagnostic usefulness of an HCV core antigen (HCV-Ag) assay in HCV-infected patients undergoing treatment with direct-acting antivirals. We analyzed 103 samples from 28 patients. Compared with RT-PCR, sensitivity was 96.2% and specificity was 100%. The correlation between techniques was excellent (Pearson coefficient: 0.871). HCV-Ag proved to be useful in patients with sustained viral response and in patients who experienced treatment failures.

  17. Antiviral Treatment of HCV-Infected Patients with B-Cell Non-Hodgkin Lymphoma: ANRS HC-13 Lympho-C Study

    PubMed Central

    Alric, Laurent; Besson, Caroline; Lapidus, Nathanael; Jeannel, Juliette; Michot, Jean-Marie; Cacoub, Patrice; Canioni, Danielle; Pol, Stanislas; Davi, Frédéric; Rabiega, Pascaline; Ysebaert, Loic; Bonnet, Delphine; Hermine, Olivier

    2016-01-01

    Hepatitis C virus (HCV) infection is associated with lymphoproliferative disorders and B-cell non-Hodgkin lymphomas (B-NHLs). Evaluation of the efficacy and safety profiles of different antiviral therapies in HCV patients with B-NHL is warranted. Methods: First, we evaluated the sustained virologic response (SVR) and safety of Peg-interferon-alpha (Peg-IFN) + ribavirin +/- first protease inhibitors (PI1s) therapy in 61 HCV patients with B-NHL enrolled in a nationwide observational survey compared with 94 matched HCV-infected controls without B-NHL. In a second series, interferon-free regimens using a newly optimal combination therapy with direct-acting antiviral drugs (DAAs) were evaluated in 10 patients with HCV and B-NHL. Results: The main lymphoma type was diffuse large B-cell lymphoma (38%) followed by marginal zone lymphoma (31%). In the multivariate analysis, patients with B-NHL treated by Peg-IFN-based therapy exhibited a greater SVR rate compared with controls, 50.8% vs 30.8%, respectively, p<0.01, odds ratio (OR) = 11.2 [2.3, 52.8]. B-NHL response was better (p = 0.02) in patients with SVR (69%) than in patients without SVR (31%). Premature discontinuation of Peg-IFN-based therapy was significantly more frequent in the B-NHL group (19.6%) compared with the control group (6.3%), p<0.02. Overall, survival was significantly enhanced in the controls than in the B-NHL group (hazard ratio = 34.4 [3.9, 304.2], p< 0.01). Using DAAs, SVR was achieved in 9/10 patients (90%). DAAs were both well tolerated and markedly efficient. Conclusions: The virologic response of HCV-associated B-NHL is high. Our study provides a comprehensive evaluation of different strategies for the antiviral treatment of B-NHL associated with HCV infection. PMID:27749916

  18. Real-World Experiences With a Direct-Acting Antiviral Agent for Patients With Hepatitis C Virus Infection

    PubMed Central

    Louie, Vincent; Latt, Nyan L; Gharibian, Derenik; Sahota, Amandeep; Yanny, Beshoy T; Mittal, Rasham; Bider-Canfield, Zoe; Cheetham, T Craig

    2017-01-01

    Context Traditional hepatitis C virus treatment was limited by low cure rates, side effects, and stringent monitoring requirements. Sofosbuvir, a direct-acting antiviral agent with a cure rate of 96%, was introduced in 2013. However, trials frequently excluded patients with advanced liver disease and prior treatment experience. This study aims to elucidate the real-world cure rates and sofosbuvir safety profile. Methods A retrospective cohort study was conducted at Kaiser Permanente Southern California involving patients with hepatitis C virus who received sofosbuvir treatment. Patients age 18 years and older were included, and pregnant patients were excluded. The primary end point was sustained virologic response at 12 weeks posttreatment. Secondary end points were safety and medication adherence. Multiple logistic regression analysis was used to compare patients with genotypes 1 and 2 infections. Results Of the 213 study patients, 42.3% had cirrhosis, and 38% were treatment-experienced. Most patients (69.5%) received dual therapy (sofosbuvir + ribavirin), whereas the remainder (30.5%) received triple therapy (sofosbuvir + ribavirin + interferon). The overall rate of sustained virologic response at 12 weeks posttreatment rate was 72.9% for genotype 1 infection, 64.7% in the treatment-experienced subgroup, and 66.7% in the cirrhosis subgroup. Rates of sustained virologic response at 12 weeks posttreatment for genotypes 2 and 3 were 90.8% and 55%, respectively. Most patients experienced anemia and fatigue. Women and patients with a lower baseline viral load were statistically more likely to be cured. Conclusion Real-world cure rates were similar to rates seen in clinical trials for genotype 2 infection and lower for genotype 1 infection. Patients with genotype 1 and 3 infection did better with triple therapy compared with dual therapy. Patients tolerated therapy well with side effects, serious adverse events, and discontinuation rates similar to clinical trials

  19. Molecular diagnostics in the management of chronic hepatitis C: key considerations in the era of new antiviral therapies

    PubMed Central

    2014-01-01

    Molecular tests that detect and/or quantify HCV RNA are important in the diagnosis and management of patients with chronic hepatitis C (CHC) undergoing anti-viral therapy. The primary goal of anti-HCV therapy is to achieve a sustained virologic response (SVR) defined as "undetectable" Hepatitis C Virus (HCV) RNA in the serum or plasma at 12 to 24 weeks following the end of treatment. HCV RNA viral load (VL) monitoring is used to guide treatment duration where decisions can be made on-therapy and to determine whether or not to stop therapy. In addition, clinicians determine treatment regimen and duration based on the HCV genotype (1-6) as well as the kinetics of HCV RNA levels. As direct acting antivirals (DAA) have revolutionized hepatitis C treatment, they have also lead to new HCV RNA VL result interpretations. Further, the clinical decisions were different for pegylated-interferon/ribavirin (PEGα/RBV)+ boceprevir or telaprevir-containing regimens approved in 2011 (e.g. one requiring an additional 4 week "lead-in" with PEGα/RBV), each having different HCV RNA values for futility rules, created complexity in clinical decisions. The future pegylated-interferon free DAA- regimens promise significantly improved cure rates along with fixed durations and simpler treatment rules. The intent of this article is to discuss the role of HCV RNA real-time PCR tests used in the management of CHC patients in the past and how this is likely to change in the era of interferon free DAA regimens. PMID:25236936

  20. Prevention strategies for blood‐borne viruses—in the Era of vaccines, direct acting antivirals and antiretroviral therapy

    PubMed Central

    Pfaender, Stephanie; von Hahn, Thomas; Steinmann, Joerg; Ciesek, Sandra

    2016-01-01

    Summary Blood‐borne viruses, such as hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and the facultative blood‐borne hepatitis E virus, are considered a major public health problem given that they are accountable for millions of deaths each year. Treatment options, including effective vaccine design, development of antiviral strategies and the implementation of antiretroviral therapy have improved substantially over the last couple of years and contribute to successful treatment and prevention of these infectious diseases. In this review, we summarise the current knowledge and concepts in prevention of transmission of these blood‐borne viruses. PMID:27185010

  1. The impact of the new antiviral regimens on patient reported outcomes and health economics of patients with chronic hepatitis C.

    PubMed

    Younossi, Zobair; Henry, Linda

    2014-12-15

    Hepatitis C is an important cause of chronic liver disease worldwide with an estimated 170 million people infected. Hepatitis C virus (HCV)-infected patients are physically and mentally impacted by fatigue, depression and anxiety causing an impairment of health related quality of life (HRQOL), lower worker productivity and other patient reported outcomes (PROs). Although anti-HCV regimens containing first generation direct acting antiviral agents (DAAs) were associated with significant side effects, the second generation DAAs, sofosbuvir (SOF) and simeprevir (SMV), are associated with fewer side effects, better tolerability and high cure rates. Despite these advantages, key stakeholders are currently trying to find ways to best integrate these new therapeutic regimens into the management of patients with chronic hepatitis C for the benefit of all. The purpose of this article is to offer insight into the other key and equally important outcomes (PRO's, HRQOL and cost) which should be considered when assessing the applicability of these new regimens for the care of patients infected with HCV. Our review provides evidence that the new treatment regimens for HCV not only have high efficacy rates but are also associated with better patient reported outcomes and cost per case of HCV cured. Additionally, compared to other medical interventions, these new regimens are cost-effective from a societal perspective.

  2. Consequences of inaccurate hepatitis C virus genotyping on the costs of prescription of direct antiviral agents in an Italian district

    PubMed Central

    Polilli, Ennio; Cento, Valeria; Restelli, Umberto; Ceccherini-Silberstein, Francesca; Aragri, Marianna; Di Maio, Velia Chiara; Sciacca, Antonina; Santoleri, Fiorenzo; Fazii, Paolo; Costantini, Alberto; Perno, Carlo Federico; Parruti, Giustino

    2016-01-01

    Available commercial assays may yield inaccurate hepatitis C virus (HCV) genotype assignment in up to 10% of cases. We investigated the cost-effectiveness of re-evaluating HCV genotype by population sequencing, prior to choosing a direct acting antiviral (DAA) regimen. Between March and September 2015, HCV sequence analysis was performed in order to confirm commercial LiPA-HCV genotype (Versant® HCV Genotype 2.0) in patients eligible for treatment with DAAs. Out of 134 consecutive patients enrolled, sequencing yielded 21 (15.7%) cases of discordant results. For three cases of wrong genotype assignment, the putative reduction in efficacy was gauged between 15% and 40%. Among the eight cases for whom G1b was assigned by commercial assays instead of G1a, potentially suboptimal treatments would have been prescribed. Finally, for five patients with G1 and indeterminate subtype, the choice of regimens would have targeted the worst option, with a remarkable increase in costs, as in the case of the four mixed HCV infections for whom pan-genotypic regimens would have been mandatory. Precise assignment of HCV genotype and subtype by sequencing may, therefore, be more beneficial than expected, until more potent pan-genotypic regimens are available for all patients. PMID:27695353

  3. Antiviral Characteristics of GSK1265744, an HIV Integrase Inhibitor Dosed Orally or by Long-Acting Injection

    PubMed Central

    Kobayashi, Masanori; Seki, Takahiro; Miki, Shigeru; Wakasa-Morimoto, Chiaki; Suyama-Kagitani, Akemi; Kawauchi-Miki, Shinobu; Taishi, Teruhiko; Kawasuji, Takashi; Johns, Brian A.; Underwood, Mark R.; Garvey, Edward P.; Sato, Akihiko; Fujiwara, Tamio

    2014-01-01

    GSK1265744 is a new HIV integrase strand transfer inhibitor (INSTI) engineered to deliver efficient antiviral activity with a once-daily, low-milligram dose that does not require a pharmacokinetic booster. The in vitro antiviral profile and mechanism of action of GSK1265744 were established through integrase enzyme assays, resistance passage experiments, and cellular assays with site-directed molecular (SDM) HIV clones resistant to other classes of anti-HIV-1 agents and earlier INSTIs. GSK1265744 inhibited HIV replication with low or subnanomolar efficacy and with a selectivity index of at least 22,000 under the same culture conditions. The protein-adjusted half-maximal inhibitory concentration (PA-EC50) extrapolated to 100% human serum was 102 nM. When the virus was passaged in the presence of GSK1265744, highly resistant mutants with more than a 10-fold change (FC) in EC50 relative to that of the wild-type were not observed for up to 112 days of culture. GSK1265744 demonstrated activity against SDM clones containing the raltegravir (RAL)-resistant Y143R, Q148K, N155H, and G140S/Q148H signature variants (FC less than 6.1), while these mutants had a high FC in the EC50 for RAL (11 to >130). Either additive or synergistic effects were observed when GSK1265744 was tested in combination with representative anti-HIV agents, and no antagonistic effects were seen. These findings demonstrate that, similar to dolutegravir, GSK1265744 is differentiated as a new INSTI, having a markedly distinct resistance profile compared with earlier INSTIs, RAL, and elvitegravir (EVG). The collective data set supports further clinical development of GSK1265744. PMID:25367908

  4. Demonstration Advanced Avionics System (DAAS) functional description. [Cessna 402B aircraft

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A comprehensive set of general aviation avionics were defined for integration into an advanced hardware mechanization for demonstration in a Cessna 402B aircraft. Block diagrams are shown and system and computer architecture as well as significant hardware elements are described. The multifunction integrated data control center and electronic horizontal situation indicator are discussed. The functions that the DAAS will perform are examined. This function definition is the basis for the DAAS hardware and software design.

  5. Human subtilase SKI-1/S1P is a master regulator of the HCV Lifecycle and a potential host cell target for developing indirect-acting antiviral agents.

    PubMed

    Olmstead, Andrea D; Knecht, Wolfgang; Lazarov, Ina; Dixit, Surjit B; Jean, François

    2012-01-01

    HCV infection is a major risk factor for liver cancer and liver transplantation worldwide. Overstimulation of host lipid metabolism in the liver by HCV-encoded proteins during viral infection creates a favorable environment for virus propagation and pathogenesis. In this study, we hypothesize that targeting cellular enzymes acting as master regulators of lipid homeostasis could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with human Flaviviridae viruses such as hepatitis C virus (HCV), whose assembly and pathogenesis depend on interaction with lipid droplets (LDs). One such master regulator of cholesterol metabolic pathways is the host subtilisin/kexin-isozyme-1 (SKI-1)--or site-1 protease (S1P). SKI-1/S1P plays a critical role in the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which control expression of the key enzymes of cholesterol and fatty-acid biosynthesis. Here we report the development of a SKI-1/S1P-specific protein-based inhibitor and its application to blocking the SREBP signaling cascade. We demonstrate that SKI-1/S1P inhibition effectively blocks HCV from establishing infection in hepatoma cells. The inhibitory mechanism is associated with a dramatic reduction in the abundance of neutral lipids, LDs, and the LD marker: adipose differentiation-related protein (ADRP)/perilipin 2. Reduction of LD formation inhibits virus assembly from infected cells. Importantly, we confirm that SKI-1/S1P is a key host factor for HCV infection by using a specific active, site-directed, small-molecule inhibitor of SKI-1/S1P: PF-429242. Our studies identify SKI-1/S1P as both a novel regulator of the HCV lifecycle and as a potential host-directed therapeutic target against HCV infection and liver steatosis. With identification of an increasing number of human viruses that use host LDs for infection, our results suggest that SKI-1/S1P inhibitors may allow development of

  6. How Generalizable Are the Results From Trials of Direct Antiviral Agents to People Coinfected With HIV/HCV in the Real World?

    PubMed Central

    Saeed, Sahar; Strumpf, Erin C.; Walmsley, Sharon L.; Rollet-Kurhajec, Kathleen; Pick, Neora; Martel-Laferrière, Valerie; Hull, Mark; Gill, M. John; Cox, Joseph; Cooper, Curtis; Klein, Marina B.

    2016-01-01

    Background. Direct-acting antivirals (DAAs) against hepatitis C virus (HCV) have been described as revolutionary. However, it remains uncertain how effective these drugs will be for individuals coinfected with human immunodeficiency virus (HIV)–HCV. Bridging this gap between efficacy and effectiveness requires a focus on the generalizability of clinical trials. Methods. Generalizability of DAA trials was assessed by applying the eligibility criteria from 5 efficacy trials: NCT01479868, PHOTON-1 (NCT01667731), TURQUOISE-I (NCT01939197), ION-4 (NCT02073656), and ALLY-2 (NCT02032888) that evaluated simeprevir; sofosbuvir; ombitasvir, paritaprevir/ritonavir/dasabuvir; sofosbuvir/ledipasvir; and daclatasvir/sofosbuvir, respectively, to the Canadian Coinfection Cohort, representing approximately 23% of the total coinfected population in care in Canada. Results. Of 874 active participants, 70% had chronic HCV, of whom 410, 26, 94, and 11 had genotypes 1, 2, 3, and 4, respectively. After applying trial eligibility criteria, only 5.9% (24/410) would have been eligible for enrollment in the simeprevir trial, 9.8% (52/530) in PHOTON-1, 6.3% (26/410) in TURQUOISE-I, and 8.1% (34/421) in ION-4. The ALLY-2 study was more inclusive; 43% (233/541) of the cohort would have been eligible. The most exclusive eligibility criteria across all trials with the exception of ALLY-2 were restriction to specific antiretroviral therapies (63%–79%) and active illicit drug use (53%–55%). Conclusions. DAA trial results may have limited generalizability, since the majority of coinfected individuals were not eligible to participate. Exclusions appeared to be related to improving treatment outcomes by not including those at higher risk of poor adherence and reinfection—individuals for whom real-world data are urgently needed. PMID:26743093

  7. Hepatitis C and double-hit B cell lymphoma successfully treated by antiviral therapy

    PubMed Central

    Galati, Giovanni; Rampa, Lorenzo; Vespasiani-Gentilucci, Umberto; Marino, Mirella; Pisani, Francesco; Cota, Carlo; Guidi, Alessandro; Picardi, Antonio

    2016-01-01

    B cells lymphoma is one of the most challenging extra-hepatic manifestations of hepatitis C virus (HCV). Recently, a new kind of B-cell lymphoma, named double-hit B (DHL), was characterized with an aggressive clinical course whereas a potential association with HCV was not investigated. The new antiviral direct agents (DAAs) against HCV are effective and curative in the majority of HCV infections. We report the first case, to our knowledge, of DHL and HCV-infection successfully treated by new DAAs. According to our experience, a DHL must be suspected in case of HCV-related lymphoma, and an early diagnosis could direct towards a different hematological management because a worse prognosis might be expected. A possible effect of DAAs on DHL regression should be investigated, but eradicating HCV would avoid life-threatening reactivation of viral hepatitis during pharmacological immunosuppression in onco-haematological diseases. PMID:27803769

  8. Hepatitis C and double-hit B cell lymphoma successfully treated by antiviral therapy.

    PubMed

    Galati, Giovanni; Rampa, Lorenzo; Vespasiani-Gentilucci, Umberto; Marino, Mirella; Pisani, Francesco; Cota, Carlo; Guidi, Alessandro; Picardi, Antonio

    2016-10-18

    B cells lymphoma is one of the most challenging extra-hepatic manifestations of hepatitis C virus (HCV). Recently, a new kind of B-cell lymphoma, named double-hit B (DHL), was characterized with an aggressive clinical course whereas a potential association with HCV was not investigated. The new antiviral direct agents (DAAs) against HCV are effective and curative in the majority of HCV infections. We report the first case, to our knowledge, of DHL and HCV-infection successfully treated by new DAAs. According to our experience, a DHL must be suspected in case of HCV-related lymphoma, and an early diagnosis could direct towards a different hematological management because a worse prognosis might be expected. A possible effect of DAAs on DHL regression should be investigated, but eradicating HCV would avoid life-threatening reactivation of viral hepatitis during pharmacological immunosuppression in onco-haematological diseases.

  9. RNA interference acts as a natural antiviral response to O'nyong-nyong virus (Alphavirus; Togaviridae) infection of Anopheles gambiae.

    PubMed

    Keene, Kimberly M; Foy, Brian D; Sanchez-Vargas, Irma; Beaty, Barry J; Blair, Carol D; Olson, Ken E

    2004-12-07

    RNA interference (RNAi) is triggered in eukaryotic organisms by double-stranded RNA (dsRNA), and it destroys any mRNA that has sequence identity with the dsRNA trigger. The RNAi pathway in Anopheles gambiae can be silenced by transfecting cells with dsRNA derived from exon sequence of the A. gambiae Argonaute2 (AgAgo2) gene. We hypothesized that RNAi may also act as an antagonist to alphavirus replication in A. gambiae because RNA viruses form dsRNA during replication. Silencing AgAgo2 expression would make A. gambiae mosquitoes more permissive to virus infection. To determine whether RNAi conditions the vector competence of A. gambiae for O'nyong-nyong virus (ONNV), we engineered a genetically modified ONNV that expresses enhanced GFP (eGFP) as a marker. After intrathoracic injection, ONNV-eGFP slowly spread to other A. gambiae tissues over a 9-day incubation period. Mosquitoes were then coinjected with virus and either control beta-galactosidase dsRNA (dsbetagal; note that "ds" is used as a prefix to indicate the dsRNA derived from a given gene throughout) or ONNV dsnsP3. Treatment with dsnsP3 inhibited virus spread significantly, as determined by eGFP expression patterns. ONNV-eGFP titers from mosquitoes coinjected with dsnsP3 were significantly lower at 3 and 6 days after injection than in mosquitoes coinjected with dsbetagal. Mosquitoes were then coinjected with ONNV-eGFP and dsAgAgo2. Mosquitoes coinjected with virus and AgAgo2 dsRNA displayed widespread eGFP expression and virus titers 16-fold higher than dsbetagal controls after 3 or 6 days after injection. These observations provide direct evidence that RNAi is an antagonist of ONNV replication in A. gambiae, and they suggest that the innate immune response conditions vector competence.

  10. UAS Integration into the NAS: iHTL: DAA Display Evaluation Preliminary Results

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, Conrad; Shively, Jay

    2014-01-01

    The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by a presentation of the preliminary 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had moderate to no affect on pilot measured response times.

  11. AIAA Aviation UAS DAA Demonstration-Mini HITL Week 2 Stats

    NASA Technical Reports Server (NTRS)

    Fern, Lisa Carolynn; Murphy, James R.; Jovic, Srboljub

    2016-01-01

    The UAS-NAS Project demo will showcase recent research efforts to ensure the interoperability between proposed UAS detect and avoid (DAA) human machine interface requirements (developed within RTCA SC-228) and existing collision avoidance displays. Attendees will be able to view the current state of the art of the DAA pilot traffic, alerting and guidance displays integrated with Traffic advisory and Collision Avoidance (TCAS) II in the UAS-NAS Project's research UAS ground control station (developed in partnership with the Air Force Research Laboratory). In addition, attendees will have the opportunity to interact with the research UAS ground control station and "fly" encounters, using the DAA and TCAS II displays to avoid simulated aircraft. The display of the advisories will be hosted on a laptop with an external 30" monitor, running the Vigilant Spririt system. DAA advisories will be generated by the JADEM software tool, connected to the system via the LVC Gateway. A repeater of the primary flight display will be shown on a 55" tv/monitor mounted on a stand at the back of the booth to show the pilot interaction to the passersby.

  12. Moderate Sustained Virologic Response Rates With 6-Week Combination Directly Acting Anti–Hepatitis C Virus Therapy in Patients With Advanced Liver Disease

    PubMed Central

    Kattakuzhy, Sarah; Wilson, Eleanor; Sidharthan, Sreetha; Sims, Zayani; McLaughlin, Mary; Price, Angie; Silk, Rachel; Gross, Chloe; Akoth, Elizabeth; McManus, Maryellen; Emmanuel, Benjamin; Shrivastava, Shikha; Tang, Lydia; Nelson, Amy; Teferi, Gebeyehu; Chavez, Jose; Lam, Brian; Mo, Hongmei; Osinusi, Anuoluwapo; Polis, Michael A.; Masur, Henry; Kohli, Anita; Kottilil, Shyamasundaran

    2016-01-01

    Background. Treatment of genotype 1 hepatitis C virus (HCV) infection with combination directly acting antivirals (DAA) for 8–24 weeks is associated with high rates of sustained virologic response (SVR). We previously demonstrated that adding a third DAA to ledipasvir and sofosbuvir (LDV/SOF) can result in high SVR rates in patients without cirrhosis. In this study, we investigated whether a similar regimen would yield equivalent rates of cure in patients with advanced liver fibrosis. Methods. Fifty patients were enrolled at the Clinical Research Center of the National Institutes of Health and associated healthcare centers. Enrollment and follow-up data from April 2014 to June 2015 are reported here. Eligible participants were aged ≥18 years, had chronic HCV genotype 1 infection (serum HCV RNA ≥2000 IU/mL), and stage 3–4 liver fibrosis. HCV RNA was measured using a reverse-transcription polymerase chain reaction assay. Results. Of patients treated with LDV, SOF, and the NS3/4A protease inhibitor GS-9451 for 6 weeks, 76% (38 of 50; 95% confidence interval, 60%–85%) had SVR achieved 12 weeks after the end of treatment. There was no statistically significant difference in treatment efficacy between treatment-naive patients (72%, 18 of 25) and those with treatment experience (80%; 20 of 25) (P = .51). Overall, 11 patients (22%) experienced virologic relapse, and 1 (2%) was lost to follow-up at 4 weeks after treatment. No serious adverse events, discontinuations, or deaths were associated with this regimen. Conclusions. Adding a third DAA to LDV/SOF may result in a moderate SVR rate, lower than that observed in patients without cirrhosis. Significant liver fibrosis remains an impediment to achieving SVR with short-duration DAA therapy. Chinese Clinical Trials Registration. CT01805882. PMID:26503379

  13. ACES M and S: Unmitigated Factorial Encounter Study on DAA/TCAS Interoperability

    NASA Technical Reports Server (NTRS)

    Thipphavong, David; Cone, Andrew; Park, Chunki; Lee, Seung Man; Santiago, Confesor

    2016-01-01

    Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements for DAA alerting and guidance systems. This presentation contains the results of two combinatorial encounter analysis studies using NASA's SAA Control fast-time simulation capability for this purpose. In these studies, encounters between two aircraft were simulated one at a time for the full factorial combination of encounter geometries (e.g., encounter angle, CPA offset) and aircraft performance (e.g., ownership and intruder ground speeds and vertical rates). The first study analyzes the relationships (e.g., timeline) between the different alerting-safety regions in the SC-228 MOPS (in order of increasing severity): 1) DAA warning alert, 2) well clear recovery (WCR) guidance, 3) DAA-Collision Avoidance (CA), and 4) TCAS RA. This study will focus primarily on encounter situations in which TCAS RA occurs prior to any of the other alerting-safety boundaries. In particular, this study will investigate whether using vertical distance or vertical distance at closest point of approach (i.e., vertical miss distance or VMD) is more appropriate for the definition of the DAA-CA region. In addition, cases where transitions between different regions skip an intermediate region will be analyzed. The second study in this presentation explores a proposal to use an altitude rate error threshold to determine if vertical maneuvers are acceptable for DAA WCR guidance against non-cooperative intruders. This study incorporates the radar from the Honeywell sensor model and examines a series of

  14. Antiviral treatment of hepatitis C virus infection and factors affecting efficacy

    PubMed Central

    Zhu, Yan; Chen, Song

    2013-01-01

    Hepatitis C virus (HCV) infection is the leading cause of chronic liver-related diseases, including cirrhosis, liver failure, and hepatocellular carcinoma. Currently, no effective vaccine is available for HCV infection. Polyethylene glycol interferon-α (PegIFN-α) in combination with ribavirin (RBV) is the standard of care (SOC) for chronic hepatitis C. However, the efficacy of PegIFN-α and RBV combination therapy is less than 50% for genotype 1 HCV, which is the dominant virus in humans. In addition, IFN and RBV have several severe side effects. Therefore, strategies to improve sustained virological response (SVR) rates have been an important focus for clinical physicians. The serine protease inhibitors telaprevir and boceprevir were approved by the United States Food and Drug Administration in 2011. The addition of HCV protease inhibitors to the SOC has significantly improved the efficacy of treatments for HCV infection. Several direct-acting antiviral drugs currently in late-stage clinical trials, both with and without peg-IFN and RBV, have several advantages over the previous SOC, including higher specificity and efficacy, fewer side effects, and the ability to be administered orally, and might be optimal regimens in the future. Factors affecting the efficacy of anti-HCV treatments based on IFN-α include the HCV genotype, baseline viral load, virological response during treatment, host IL28B gene polymorphisms and hepatic steatosis. However, determining the effect of the above factors on DAA therapy is necessary. In this review, we summarize the development of anti-HCV agents and assess the main factors affecting the efficacy of antiviral treatments. PMID:24379621

  15. What are the promising new therapies in the field of chronic hepatitis C after the first-generation direct-acting antivirals?

    PubMed

    Hunt, Douglas; Pockros, Paul

    2013-01-01

    A number of promising new hepatitis C virus (HCV) antiviral regimens have emerged during the last few years, with a trend toward increased efficacy, safety, and tolerability, when compared with currently available therapies. The focus of recent HCV antiviral drug development has been on inhibition of HCV replication, largely by targeting specific components of the HCV replication complex itself. A significant effort has been put into generating drugs that inhibit the NS5B polymerase. A number of such drugs have been developed, and NS5B polymerase inhibitors can be divided into nucleoside polymerase inhibitors and nonnucleoside polymerase inhibitors, with each group carrying specific pharmacologic and clinical characteristics. Additional research has explored the efficacy of drugs that inhibit the HCV replication complex via other mechanisms. Second-generation NS3-4A protease inhibitors have been developed, which have generally improved on the efficacy of the currently available FDA-approved first-generation agents. NS5A inhibitors have also been studied. These medications impede HCV replication and viral particle assembly and enhance host immune activation via novel mechanisms. Alternatively, medications that target a host protein, cyclophillin B, are under evaluation. These medications block HCV replication via modification of the effects of NS5B and via other poorly understood mechanisms. Detailed below are the most important HCV antiviral agents under development, many of which show promise for use within the next few years.

  16. Importance of very early HCV RNA kinetics for prediction of treatment outcome of highly effective all oral direct acting antiviral combination therapy.

    PubMed

    Sarrazin, Christoph; Wedemeyer, Heiner; Cloherty, Gavin; Cohen, Daniel E; Chevaliez, Stephane; Herman, Christine; Bernstein, Barry; Pawlotsky, Jean Michel

    2015-03-01

    Interferon-free combination therapies lead to rapid suppression of HCV RNA early during treatment. The potential to predict virologic response and failure as well as to guide treatment duration with measurement of HCV RNA very early during treatment by highly sensitive assays is not well known. In 11 IL28B CC (rs12979860) patients infected with HCV genotype 1, who received DAA combination therapy with the NS3 protease inhibitor ABT-450/r together with the non-nucleoside NS5B polymerase inhibitor ABT-072 and ribavirin for 12 weeks, HCV RNA was assessed frequently by the RealTime HCV (ART) and the High-Pure-System/Cobas TaqMan (HPS) assays during and after treatment. Overall, at 33 of 131 time points during treatment residual HCV RNA was detectable by ART but undetectable by HPS while the converse was observed in only two samples. Of the two patients who experienced virologic relapse, one patient had residual viremia at week 6 of treatment by ART only while the other patient never had undetectable HCV RNA by the ART assay. However, residual viremia was also observed by ART as late as therapy weeks 9, 10 and 12 in patients with subsequent sustained virologic response. In patients with sustained response no viremia was observed at multiple time points during post-treatment follow up by either assay. The higher sensitivity of the ART in comparison to the HPS assay may be associated with more frequent detection of residual viremia during highly effective, interferon-free combination therapies. However, the significance of this finding in predicting virologic failure appears to be limited.

  17. Hepatitis C Virus and Antiviral Drug Resistance

    PubMed Central

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

    2016-01-01

    Since its discovery in 1989, hepatitis C virus (HCV) has been intensively investigated to understand its biology and develop effective antiviral therapies. The efforts of the previous 25 years have resulted in a better understanding of the virus, and this was facilitated by the development of in vitro cell culture systems for HCV replication. Antiviral treatments and sustained virological responses have also improved from the early interferon monotherapy to the current all-oral regimens using direct-acting antivirals. However, antiviral resistance has become a critical issue in the treatment of chronic hepatitis C, similar to other chronic viral infections, and retreatment options following treatment failure have become important questions. Despite the clinical challenges in the management of chronic hepatitis C, substantial progress has been made in understanding HCV, which may facilitate the investigation of other closely related flaviviruses and lead to the development of antiviral agents against these human pathogens. PMID:27784846

  18. Indian National Association for Study of the Liver (INASL) Guidance for Antiviral Therapy Against HCV Infection: Update 2016.

    PubMed

    Puri, Pankaj; Saraswat, Vivek A; Dhiman, Radha K; Anand, Anil C; Acharya, Subrat K; Singh, Shivaram P; Chawla, Yogesh K; Amarapurkar, Deepak N; Kumar, Ajay; Arora, Anil; Dixit, Vinod K; Koshy, Abraham; Sood, Ajit; Duseja, Ajay; Kapoor, Dharmesh; Madan, Kaushal; Srivastava, Anshu; Kumar, Ashish; Wadhawan, Manav; Goel, Amit; Verma, Abhai; Shalimar; Pandey, Gaurav; Malik, Rohan; Agrawal, Swastik

    2016-06-01

    India contributes significantly to the global burden of HCV. While the nucleoside NS5B inhibitor sofosbuvir became available in the Indian market in March 2015, the other directly acting agents (DAAs), Ledipasvir and Daclatasvir, have only recently become available in the India. The introduction of these DAA in India at a relatively affordable price has led to great optimism about prospects of cure for these patients as not only will they provide higher efficacy, but combination DAAs as all-oral regimen will result in lower side effects than were seen with pegylated interferon alfa and ribavirin therapy. Availability of these newer DAAs has necessitated revision of INASL guidelines for the treatment of HCV published in 2015. Current considerations for the treatment of HCV in India include the poorer response of genotype 3, nonavailability of many of the DAAs recommended by other guidelines and the cost of therapy. The availability of combination DAA therapy has simplified therapy of HCV with decreased reliance of evaluation for monitoring viral kinetics or drug related side effects.

  19. Treating Hepatitis C in a Ryan White-Funded HIV Clinic: Has the Treatment Uptake Improved in the Interferon-Free Directly Active Antiviral Era?

    PubMed Central

    Cope, Rebecca; Glowa, Thomas; Faulds, Samantha; McMahon, Deborah

    2016-01-01

    Abstract Now that highly efficacious, interferon-free (IFN-free), direct acting antivirals (DAA) for the treatment of hepatitis C (HCV) have closed the gap between treatment and cure, identifying barriers that prevent initiation of treatment is more crucial than ever. This is a retrospective study utilizing Electronic Medical Records and Prior Authorization Records to identify HCV treatment gaps, including predictors for intention-to-treat and treatment initiation in the first 15 months of a Ryan White funded human immunodeficiency virus (HIV)/HCV co-infection clinic. This study included 128 adults ≥18 years old with HIV and chronic HCV infection who had visited the treatment center at least once since January 2013. Provider intent-to-treat was used to differentiate patients actively considered for treatment based on documentation kept by a multidisciplinary HCV team. Members of this group who had gone on to initiate treatment were identified. Baseline characteristics were compared. Rates of active treatment consideration and treatment initiation were 30% and 14%, respectively. HCV treatment-naïve individuals were less likely to be considered for treatment [risk ratio (RR) 1.58, 95% confidence interval (CI) 1.07–2.32] and initiate therapy (RR 2.33, 95% CI 0.97–5.60). Advanced liver disease had no significant association. Black race (RR 1.96, 95% CI 0.90–4.25) and Medicaid insurance holders (RR 1.90, 95% CI 0.95–3.82) tended to be less likely to initiate therapy. The availability of IFN-free DAA regimens has yet to increase HCV treatment uptake in our HIV/HCV co-infected population. Barriers to HCV treatment initiation have shifted from medical contraindications to socioeconomic variables. PMID:26744994

  20. Multiplexed LC-MS/MS method for the simultaneous quantitation of three novel hepatitis C antivirals, daclatasvir, asunaprevir, and beclabuvir in human plasma.

    PubMed

    Jiang, Hao; Kandoussi, Hamza; Zeng, Jianing; Wang, Jian; Demers, Roger; Eley, Timothy; He, Bing; Burrell, Richard; Easter, John; Kadiyala, Pathanjali; Pursley, Janice; Cojocaru, Laura; Baker, Chanda; Ryan, John; Aubry, Anne-Françoise; Arnold, Mark E

    2015-03-25

    Dual or triple combination regimens of novel hepatitis C direct-acting antivirals (DAA, daclatasvir, asunaprevir, or beclabuvir) provide high sustained virological response rates and reduced frequency of resistance compared to clinical monotherapy. To support pharmacokinetic (PK) assessments in clinical studies, a multiplexed liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantitation of daclatasvir, asunaprevir, beclabuvir (BMS-791325) and its active metabolite (BMS-794712) in human plasma was developed and validated. Human plasma samples were extracted with methyl-t-butyl ether followed by an LC-MS/MS analysis, which was conducted in a multiple reaction monitoring (MRM) mode. The lower limits of quantitation (LLOQ) were 1 ng/mL for daclatasvir, asunaprevir, and BMS-794712, and 2 ng/mL for beclabuvir. Intra-run precision (≤4.5% CV), inter-run precision (≤2.9% CV), and accuracy (±5.3% deviation) based on different concentration levels (low, geometric mean, mid and high) of the quality control samples (QCs) provided evidence of the methods accuracy and precision. Selectivity and matrix effect on LC-MS/MS detection, stability in plasma, and potential interference of coadministered drugs (ribavirin and interferon) were all evaluated and the results were acceptable. Method reproducibility was demonstrated by the reanalysis of a portion of study samples. The cross-validation results for QCs demonstrated the equivalency between this method and two single-analyte methods which were previously validated for quantitation of daclatasvir in human plasma. This approach of using a multiplexed LC-MS/MS method for the simultaneous quantitation of three DAAs is time- and cost-effective, and can maintain good data quality in sample analysis.

  1. Treatment Selection Choices Should Not Be Based on Benefits or Costs Alone: A Head-to-Head Randomized Controlled Trial of Antiviral Drugs for Hepatitis C

    PubMed Central

    Davitkov, Perica; Chandar, Apoorva Krishna; Hirsch, Amy; Compan, Anita; Silveira, Marina G.; Anthony, Donald D.; Smith, Suzanne; Gideon, Clare; Bonomo, Robert A.; Falck-Ytter, Yngve

    2016-01-01

    Background Clinicians often face dilemmas with decisions related to formulary choices when two similar drugs are simultaneously available in the market. We studied the comparative safety, effectiveness, and treatment costs of the two first generation direct-acting antiviral agents (DAA), boceprevir and telaprevir as uncertainty existed regarding the drug of choice between these two seemingly equally Hepatitis-C treatment options. Methods We randomly assigned 50 patients in an open-label, pragmatic randomized controlled trial (RCT) at a VA Medical Center to either boceprevir or telaprevir in combination with peginterferon and ribavirin, stratified by the presence of cirrhosis and prior treatment experience. Tolerability was assessed at each visit and reasons for discontinuation of treatment and severity of adverse events due to PI treatment were adjudicated using a blinded adjudication committee. The primary outcome was difference in tolerability between boceprevir vs. telaprevir. Secondary outcomes included viral response rates and cost-per cure achieved. Results Higher rates of treatment discontinuations and/or severe DAA associated adverse events were seen in 10/25 (40%) patients randomized to telaprevir compared to 2/25 (8%) patients randomized to boceprevir (RR: 5; 95% CI: 1.2, 20; p<0.01). Cure rates did not appear to be significantly different between groups (telaprevir vs. boceprevir: RR 1.23; 95% CI: 0.76, 1.99; p = 0.39). On an intention-to-treat basis, total cost per cure was $44,329 for boceprevir vs. $57,115 for telaprevir. The significant side effect profile of telaprevir combined with the availability of highly efficacious second generation DAAs led to the early discontinuation of the trial. Conclusion Telaprevir is associated with a significantly higher rate of severe adverse events leading to treatment discontinuations, hospitalizations or severe anemia and a substantially higher cost per SVR when compared to boceprevir. Real-time, point of care

  2. The pedagogical value of Disassemble/Analyze/Assemble (DAA) activities: Assessing the potential for motivation and transfer

    NASA Astrophysics Data System (ADS)

    Dalrymple, Odesma Onika

    Undergraduate engineering institutions are currently seeking to improve recruiting practices and to retain engineering majors particularly by addressing what many studies document as a major challenge of poor instruction. There is an undisputed need for instructional practices that motivate students in addition to facilitating the transfer of learning beyond the classroom. Reverse engineering and product dissection, more broadly termed Disassemble/Analyze/Assemble (DAA) activities, have shown potential to address these concerns, based on the reviews of students and professors alike. DAA activities involve the systematic deconstruction of an artifact, the subsequent analysis and possible reconstruction of its components for the purpose of understanding the embodied fundamental concepts, design principles and developmental processes. These activities have been part of regular industry practice for some time; however, the systematic analysis of their benefits for learning and instruction is a relatively recent phenomenon. A number of studies have provided highly descriptive accounts of curricula and possible outcomes of DAA activities; but, relatively few have compared participants doing DAA activities to a control group doing more traditional activities. In this respect, two quasi-experiments were conducted as part of a first-year engineering laboratory, and it was hypothesized that students who engaged in the DAA activity would be more motivated and would demonstrate higher frequencies of transfer than the control. A DAA activity that required students to disassemble a single-use camera and analyze its components to discover how it works was compared to a step-by-step laboratory activity in the first experiment and a lecture method of instruction in the second experiment. In both experiments, over forty percent of the students that engaged in the DAA activity demonstrated the ability to transfer the knowledge gained about the functions of the camera's components and

  3. Directional antenna array (DAA) for communications, control, and data link protection

    NASA Astrophysics Data System (ADS)

    Molchanov, Pavlo A.; Contarino, Vincent M.

    2013-06-01

    A next generation of Smart antennas with point-to-point communication and jam, spoof protection capability by verification of spatial position is offered. A directional antenna array (DAA) with narrow irradiation beam provides counter terrorism protection for communications, data link, control and GPS. Communications are "invisible" to guided missiles because of 20 dB smaller irradiation outside the beam and spatial separation. This solution can be implemented with current technology. Directional antennas have higher gain and can be multi-frequency or have wide frequency band in contrast to phase antenna arrays. This multi-directional antenna array provides a multi-functional communication network and simultaneously can be used for command control, data link and GPS.

  4. UAS Integration in the NAS Project: DAA-TCAS Interoperability "mini" HITL Primary Results

    NASA Technical Reports Server (NTRS)

    Rorie, Conrad; Fern, Lisa; Shively, Jay; Santiago, Confesor

    2016-01-01

    At the May 2015 SC-228 meeting, requirements for TCAS II interoperability became elevated in priority. A TCAS interoperability workgroup was formed to identify and address key issues/questions. The TCAS workgroup came up with an initial list of questions and a plan to address those questions. As part of that plan, NASA proposed to run a mini HITL to address display, alerting and guidance issues. A TCAS Interoperability Workshop was held to determine potential display/alerting/guidance issues that could be explored in future NASA mini HITLS. Consensus on main functionality of DAA guidance when TCAS II RA occurs. Prioritized list of independent variables for experimental design. Set of use cases to stress TCAS Interoperability.

  5. Antivirals against animal viruses.

    PubMed

    Villa, T G; Feijoo-Siota, L; Rama, J L R; Ageitos, J M

    2016-09-30

    Antivirals are compounds used since the 1960s that can interfere with viral development. Some of these antivirals can be isolated from a variety of sources, such as animals, plants, bacteria or fungi, while others must be obtained by chemical synthesis, either designed or random. Antivirals display a variety of mechanisms of action, and while some of them enhance the animal immune system, others block a specific enzyme or a particular step in the viral replication cycle. As viruses are mandatory intracellular parasites that use the host's cellular machinery to survive and multiply, it is essential that antivirals do not harm the host. In addition, viruses are continually developing new antiviral resistant strains, due to their high mutation rate, which makes it mandatory to continually search for, or develop, new antiviral compounds. This review describes natural and synthetic antivirals in chronological order, with an emphasis on natural compounds, even when their mechanisms of action are not completely understood, that could serve as the basis for future development of novel and/or complementary antiviral treatments.

  6. The liver partition coefficient-corrected inhibitory quotient and the pharmacokinetic-pharmacodynamic relationship of directly acting anti-hepatitis C virus agents in humans.

    PubMed

    Duan, Jianmin; Bolger, Gordon; Garneau, Michel; Amad, Ma'an; Batonga, Joëlle; Montpetit, Hélène; Otis, François; Jutras, Martin; Lapeyre, Nicole; Rhéaume, Manon; Kukolj, George; White, Peter W; Bethell, Richard C; Cordingley, Michael G

    2012-10-01

    Pharmacokinetic-pharmacodynamic (PK-PD) data analyses from early hepatitis C virus (HCV) clinical trials failed to show a good correlation between the plasma inhibitory quotient (IQ) and antiviral activity of different classes of directly acting antiviral agents (DAAs). The present study explored whether use of the liver partition coefficient-corrected IQ (LCIQ) could improve the PK-PD relationship. Animal liver partition coefficients (Kp(liver)) were calculated from liver to plasma exposure ratios. In vitro hepatocyte partition coefficients (Kp(hep)) were determined by the ratio of cellular to medium drug concentrations. Human Kp(liver) was predicted using an in vitro-in vivo proportionality method: the species-averaged animal Kp(liver) multiplied by the ratio of human Kp(hep) over those in animals. LCIQ was calculated using the IQ multiplied by the predicted human Kp(liver). Our results demonstrated that the in vitro-in vivo proportionality approach provided the best human Kp(liver) prediction, with prediction errors of <45% for all 5 benchmark drugs evaluated (doxorubicin, verapamil, digoxin, quinidine, and imipramine). Plasma IQ values correlated poorly (r(2) of 0.48) with maximum viral load reduction and led to a corresponding 50% effective dose (ED(50)) IQ of 42, with a 95% confidence interval (CI) of 0.1 to 148534. In contrast, the LCIQ-maximum VLR relationship fit into a typical sigmoidal curve with an r(2) value of 0.95 and an ED(50) LCIQ of 121, with a 95% CI of 83 to 177. The present study provides a novel human Kp(liver) prediction model, and the LCIQ correlated well with the viral load reductions observed in short-term HCV monotherapy of different DAAs and provides a valuable tool to guide HCV drug discovery.

  7. Effects of Resistance-Associated NS5A Mutations in Hepatitis C Virus on Viral Production and Susceptibility to Antiviral Reagents

    PubMed Central

    Nitta, Sayuri; Asahina, Yasuhiro; Matsuda, Mami; Yamada, Norie; Sugiyama, Ryuichi; Masaki, Takahiro; Suzuki, Ryosuke; Kato, Nobuyuki; Watanabe, Mamoru; Wakita, Takaji; Kato, Takanobu

    2016-01-01

    Direct-acting antivirals (DAAs) for hepatitis C virus (HCV) have potent anti-HCV effects but may provoke resistance-associated variants (RAVs). In this study, we assessed the characteristics of these RAVs and explored efficacious anti-HCV reagents using recombinant HCV with NS5A from a genotype 1b strain. We replaced the NS5A of JFH1 with that of Con1 (JFH1/5ACon1) and introduced known NS5A inhibitor resistance mutations (L31M, L31V, L31I and Y93H) individually or in combination. Susceptibilities against anti-HCV reagents were also investigated. RAVs with Y93H exhibited high extracellular core antigen levels and infectivity titers. Variants with any single mutation showed mild to moderate resistance against NS5A inhibitors, whereas variants with double mutations at both L31 and Y93 showed severe resistance. The variants with mutations exhibited similar levels of susceptibility to interferon (IFN)-α, IFN-λ1, IFN-λ3 and Ribavirin. Variants with the Y93H mutation were more sensitive to protease inhibitors compared with JFH1/5ACon1. In conclusion, the in vitro analysis indicated that the Y93H mutation enhanced infectious virus production, suggesting advantages in the propagation of RAVs with this mutation. However, these RAVs were susceptible to protease inhibitors. Thus, a therapeutic regimen that includes these reagents is a promising means to eradicate these RAVs. PMID:27703205

  8. An Evaluation of Detect and Avoid (DAA) Displays for Unmanned Aircraft Systems: The Effect of Information Level and Display Location on Pilot Performance

    NASA Technical Reports Server (NTRS)

    Fern, Lisa; Rorie, R. Conrad; Pack, Jessica S.; Shively, R. Jay; Draper, Mark H.

    2015-01-01

    A consortium of government, industry and academia is currently working to establish minimum operational performance standards for Detect and Avoid (DAA) and Control and Communications (C2) systems in order to enable broader integration of Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). One subset of these performance standards will need to address the DAA display requirements that support an acceptable level of pilot performance. From a pilot's perspective, the DAA task is the maintenance of self separation and collision avoidance from other aircraft, utilizing the available information and controls within the Ground Control Station (GCS), including the DAA display. The pilot-in-the-loop DAA task requires the pilot to carry out three major functions: 1) detect a potential threat, 2) determine an appropriate resolution maneuver, and 3) execute that resolution maneuver via the GCS control and navigation interface(s). The purpose of the present study was to examine two main questions with respect to DAA display considerations that could impact pilots' ability to maintain well clear from other aircraft. First, what is the effect of a minimum (or basic) information display compared to an advanced information display on pilot performance? Second, what is the effect of display location on UAS pilot performance? Two levels of information level (basic, advanced) were compared across two levels of display location (standalone, integrated), for a total of four displays. The authors propose an eight-stage pilot-DAA interaction timeline from which several pilot response time metrics can be extracted. These metrics were compared across the four display conditions. The results indicate that the advanced displays had faster overall response times compared to the basic displays, however, there were no significant differences between the standalone and integrated displays. Implications of the findings on understanding pilot performance on the DAA task, the

  9. Current Landscape of Antiviral Drug Discovery

    PubMed Central

    Blair, Wade; Cox, Christopher

    2016-01-01

    Continued discovery and development of new antiviral medications are paramount for global human health, particularly as new pathogens emerge and old ones evolve to evade current therapeutic agents. Great success has been achieved in developing effective therapies to suppress human immunodeficiency virus (HIV) and hepatitis B virus (HBV); however, the therapies are not curative and therefore current efforts in HIV and HBV drug discovery are directed toward longer-acting therapies and/or developing new mechanisms of action that could potentially lead to cure, or eradication, of the virus. Recently, exciting early clinical data have been reported for novel antivirals targeting respiratory syncytial virus (RSV) and influenza (flu). Preclinical data suggest that these new approaches may be effective in treating high-risk patients afflicted with serious RSV or flu infections. In this review, we highlight new directions in antiviral approaches for HIV, HBV, and acute respiratory virus infections. PMID:26962437

  10. Photoinduced charge recombination in dipolar D-A-A photonic liquid crystal polymorphs.

    PubMed

    Mazza, Mercedes M A; Yamazaki, Shiori; Mai, Dieu X; Padgaonkar, Suyog; Peurifoy, Samuel; Goncalves, Ariane; Wu, Yi-Lin; Hu, Qiaoyu; Scott, Amy M

    2017-02-08

    A hexylalkoxy dipolar D-A-A molecule [7-(4-N,N-(bis(4-hexyloxyphenyl)amino)phenyl)-2,1,3-(benzothia-diazol-4-yl)methylene]propane-dinitrile, (C6-TPA-BT-CN) has been synthesized and the photophysics studied via femtosecond transient absorption spectroscopy (FsTA) in toluene and in amorphous and liquid crystalline spherulite thin films. Two spherulite macromolecular crystalline phases (banded, and non-banded) were observed through concentration dependent, solution processing techniques and are birefringent with a negative sign of elongation. A dramatic change in the electronic absorption from blue in amorphous films to green in spherulites was observed, and the molecular orientation was determined through the combined analysis of polarized light microscopy, X-ray diffraction, and scanning electron microscopy. FsTA was performed on amorphous films and show complex charge recombination dynamics, and a Stark effect, characterized from the combined TPA+˙ and [BT-CN]-˙ spectroscopic signatures at 450 nm and 510 nm and identified through spectroelectrochemistry. Radical cation dynamics of TPA+˙ was observed selectively at 750 nm with >503.3 ps (18%) recombination kinetics resulting in a rather significant yield of free charge carriers in amorphous films and consistent with previous reports on energetically disordered blend films. However, photoexcitation on large, non-banded spherulites areas (>250 μm) reveal average monoexponential charge recombination lifetimes of 169.2 ps from delocalized states similar to those observed in amorphous films and are 5× longer-lived than previous reports [Chang et al., J. Am. Chem. Soc., 2013, 135, 8790] of a related methyl-DPAT-BT-CN whose amorphous thin films were prepared through vapor deposition. Thus, the correlation between the microstructure of the blend film and the photoinduced radical pair dynamics described here is critical for developing a fundamental understanding of how dipolar states contribute to the charge carrier

  11. Antiviral immunity in crustaceans.

    PubMed

    Liu, Haipeng; Söderhäll, Kenneth; Jiravanichpaisal, Pikul

    2009-08-01

    Viral diseases of shrimp have caused negative effects on the economy in several countries in Asia, South America and America, where they have numerous shrimp culture industries. The studies on the immunity of shrimp and other crustaceans have mainly focused on general aspects of immunity and as a consequence little is known about the antiviral responses in crustaceans. The aim of this review is to update recent knowledge of innate immunity against viral infections in crustaceans. Several antiviral molecules have been isolated and characterized recently from decapods. Characterization and identification of these molecules might provide a promising strategy for protection and treatment of these viral diseases. In addition dsRNA-induced antiviral immunity is also included.

  12. Effect of Cigarette Smoking on a Marker for Neuroinflammation: A [(11)C]DAA1106 Positron Emission Tomography Study.

    PubMed

    Brody, Arthur L; Hubert, Robert; Enoki, Ryutaro; Garcia, Lizette Y; Mamoun, Michael S; Okita, Kyoji; London, Edythe D; Nurmi, Erika L; Seaman, Lauren C; Mandelkern, Mark A

    2017-03-06

    In the brain, microglia continuously scan the surrounding extracellular space, in order to respond to damage or infection by becoming activated and participating in neuroinflammation. When activated, microglia increase the expression of the translocator protein (TSPO) 18 kDa, thereby making TSPO expression a marker for neuroinflammation. We used the radiotracer [(11)C]DAA1106 (a ligand for TSPO) and positron emission tomography (PET) to determine the effect of smoking on availability of this marker for neuroinflammation. Forty-five participants (30 smokers and 15 non-smokers) completed the study and had usable data. Participants underwent a dynamic PET scanning session with bolus injection of [(11)C]DAA1106 (with smokers in the satiated state) and blood draws during PET scanning to determine TSPO affinity genotype and plasma nicotine levels. Whole brain standardized uptake values (SUVs) were determined, and analysis of variance was performed, with group (smoker vs non-smoker) and genotype as factors, thereby controlling for genotype. Smokers and non-smokers differed in whole brain SUVs (P=0.006) due to smokers having 16.8% lower values than non-smokers. The groups did not differ in injected radiotracer dose or body weight, which were used to calculate SUV. An inverse association was found between whole brain SUV and reported cigarettes per day (P<0.05), but no significant relationship was found for plasma nicotine. Thus, smokers have less [(11)C]DAA1106 binding globally than nonsmokers, indicating less microglial activation. Study findings are consistent with much prior research demonstrating that smokers have impaired inflammatory functioning compared to non-smokers and that constituents of tobacco smoke other than nicotine affect inflammatory processes.Neuropsychopharmacology accepted article preview online, 06 March 2017. doi:10.1038/npp.2017.48.

  13. Smallpox Antiviral Drug

    DTIC Science & Technology

    2007-01-01

    Nevirapine 1996 HIV Delavirdine 1997 HIV Abacavir 1998 HIV Efavirenz 1998 HIV Tenofovir 2001 HIV Adefovirn dipivoxil 2002 HBV Emtricitabine 2003 HIV Acyclovir...toxicity, hair loss, and skin changes [De Benedittis et al., 2004]. The other approach to orthopoxvirus antiviral drug discovery is to screen new...Rouzioux C. 2004. Penetration of enfuvirtide, tenofovir, efavirenz , and protease inhibitors in the genital tract of HIV-1-infected men. Aids 18:1958

  14. Broad-spectrum antiviral agents

    PubMed Central

    Zhu, Jun-Da; Meng, Wen; Wang, Xiao-Jia; Wang, Hwa-Chain R.

    2015-01-01

    Development of highly effective, broad-spectrum antiviral agents is the major objective shared by the fields of virology and pharmaceutics. Antiviral drug development has focused on targeting viral entry and replication, as well as modulating cellular defense system. High throughput screening of molecules, genetic engineering of peptides, and functional screening of agents have identified promising candidates for development of optimal broad-spectrum antiviral agents to intervene in viral infection and control viral epidemics. This review discusses current knowledge, prospective applications, opportunities, and challenges in the development of broad-spectrum antiviral agents. PMID:26052325

  15. Research progress on the direct antiviral drugs for hepatitis C virus.

    PubMed

    Gao, Jianjun; Ju, Chuanxia

    2017-03-22

    Hepatitis C, caused by the hepatitis C virus (HCV) that attacks the liver and leads to inflammation, is a severe threat to human health. Pegylated interferon α (INF-α) and ribavirin based therapy was once the standard therapy for HCV infection. However, it is suboptimal in efficacy and poorly tolerated in some patients. In the last five years, four classes of direct antiviral drugs (NAAs) that target non-structural proteins (NS) of the virus including NS3/NS4A, NS5A, and NS5B have been developed and opened a new era in HCV treatment as they are more effective and tolerable than the INF-α and ribavirin combination regimen. Importantly, the newly introduced multiple NAAs combination therapy makes it possible to eradicate all genotypes of HCV. We review recent progress on the research and development of DAAs in the present article.

  16. [Antiviral therapy in herpetic keratitis].

    PubMed

    Popa, D P; Ivaşcu, M; Ristea, L

    1994-01-01

    The frequency of ocular herpes has increased in the last time. The pathogenic mechanisms of herpetic ocular inflammation consist in cells degeneration produced by intracell virus accumulation, and immunopathological processes. It is presented the antiviral treatment in ocular herpes and antiviral efficacity of acyclovir, in comparison with other chemotherapeutics.

  17. Antiviral activities of photoactive perylenequinones.

    PubMed

    Hudson, J B; Imperial, V; Haugland, R P; Diwu, Z

    1997-02-01

    Nine perylenequinones (PQ), including some familiar naturally occurring pigments, were compared for their light-mediated antiviral efficacies. Calphostin C was the most active compound against the two target viruses, herpes simplex virus type 1 and Sindbis virus. Hypocrellins A and B were also very active. However, three cercosporin-like PQ were substantially less active in spite of their high quantum yields of singlet oxygen, whereas phleichrome, another efficient singlet oxygen producer, showed no detectable antiviral activity. One other PQ, which was a very weak singlet oxygen producer, also showed no antiviral activity. None of the active compounds showed significant antiviral activity in the dark. Thus, for some groups of PQ there was correlation between quantum yield of singlet oxygen (1O2) and antiviral efficacy, but there are evidently other structural features of PQ that influence activity.

  18. Antiviral Actions of Interferons

    PubMed Central

    Samuel, Charles E.

    2001-01-01

    Tremendous progress has been made in understanding the molecular basis of the antiviral actions of interferons (IFNs), as well as strategies evolved by viruses to antagonize the actions of IFNs. Furthermore, advances made while elucidating the IFN system have contributed significantly to our understanding in multiple areas of virology and molecular cell biology, ranging from pathways of signal transduction to the biochemical mechanisms of transcriptional and translational control to the molecular basis of viral pathogenesis. IFNs are approved therapeutics and have moved from the basic research laboratory to the clinic. Among the IFN-induced proteins important in the antiviral actions of IFNs are the RNA-dependent protein kinase (PKR), the 2′,5′-oligoadenylate synthetase (OAS) and RNase L, and the Mx protein GTPases. Double-stranded RNA plays a central role in modulating protein phosphorylation and RNA degradation catalyzed by the IFN-inducible PKR kinase and the 2′-5′-oligoadenylate-dependent RNase L, respectively, and also in RNA editing by the IFN-inducible RNA-specific adenosine deaminase (ADAR1). IFN also induces a form of inducible nitric oxide synthase (iNOS2) and the major histocompatibility complex class I and II proteins, all of which play important roles in immune response to infections. Several additional genes whose expression profiles are altered in response to IFN treatment and virus infection have been identified by microarray analyses. The availability of cDNA and genomic clones for many of the components of the IFN system, including IFN-α, IFN-β, and IFN-γ, their receptors, Jak and Stat and IRF signal transduction components, and proteins such as PKR, 2′,5′-OAS, Mx, and ADAR, whose expression is regulated by IFNs, has permitted the generation of mutant proteins, cells that overexpress different forms of the proteins, and animals in which their expression has been disrupted by targeted gene disruption. The use of these IFN system

  19. 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

  20. Antiviral immunity in amphibians.

    PubMed

    Chen, Guangchun; Robert, Jacques

    2011-11-01

    Although a variety of virus species can infect amphibians, diseases caused by ranaviruses ([RVs]; Iridoviridae) have become prominent, and are a major concern for biodiversity, agriculture and international trade. The relatively recent and rapid increase in prevalence of RV infections, the wide range of host species infected by RVs, the variability in host resistance among population of the same species and among different developmental stages, all suggest an important involvement of the amphibian immune system. Nevertheless, the roles of the immune system in the etiology of viral diseases in amphibians are still poorly investigated. We review here the current knowledge of antiviral immunity in amphibians, focusing on model species such as the frog Xenopus and the salamander (Ambystoma tigrinum), and on recent progress in generating tools to better understand how host immune defenses control RV infections, pathogenicity, and transmission.

  1. Syntheses of D-A-A Type Small Molecular Donor Materials Having Various Electron Accepting Moiety for Organic Photovoltaic Application.

    PubMed

    Kim, Nahyeon; Park, Sangman; Lee, Myong-Hoon; Lee, Jaemin; Lee, Changjin; Yoon, Sung Cheol

    2016-03-01

    Small molecular donor, DTDCTB achieved a high power conversion efficiency (PCE) value of 6.6 ± 0.2% in vacuum-deposited planar mixed heterojunction (PMHJ) structure. However, the same material just recorded PCE of 0.34% in solution processed small molecule based bulk heterjunction (BHJ) organic photovoltaic cells. For the improvement of organic photovoltaic cells (OPVs), In this study, we designed and synthesized several D-A-A (donor-acceptor-acceptor) type molecular electron donating materials. Ditolylaminothienyl moiety as an electron donating group connected to 1,2,5-benzothiadiazole as a conjugated electron accepting unit, simultaneously with an electron accepting terminal group such as cyano alkyl acetate and N-alkyl rhodanine. The thermal, photophysical, and electrochemical properties of prepared small molecules were investigated by DSC, UV/Vis spectroscopy and Cyclic Voltametry, respectively. As a result, 0.89% of PCE can be obtained from OPV using a mixture of DTATBTER and PCBM as an active layer with a Voc of 0.87 V, a Jsc of 3.20 mA/cm2, and a fill factor of 31.9%.

  2. Laboratory evaluation of the Design Analysis Associates DAA H-3613i radar water-level sensor—Results of temperature, distance, and SDI-12 tests

    USGS Publications Warehouse

    Carnley, Mark V.

    2016-09-30

    The Design Analysis Associates (DAA) DAA H-3613i radar water-level sensor (DAA H-3613i), manufactured by Xylem Incorporated, was evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) for conformance to manufacturer’s accuracy specifications for measuring a distance throughout the sensor’s operating temperature range, for measuring distances from 3 to 15 feet at ambient temperatures, and for compliance with the SDI-12 serial-to-digital interface at 1200-baud communication standard. The DAA H-3613i is a noncontact water-level sensor that uses pulsed radar to measure the distance between the radar and the water surface from 0.75 to 131 feet over a temperature range of −40 to 60 degrees Celsius (°C). Manufacturer accuracy specifications that were evaluated, the test procedures that followed, and the results obtained are described in this report. The sensor’s accuracy specification of ± 0.01 feet (± 3 millimeters) meets USGS requirements for a primary water-stage sensor used in the operation of a streamgage. The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during temperature testing at a distance of 8 feet from the target over its temperature-compensated operating range of −40 to 60 °C, except at 60 °C. At 60 °C, about half the measurements exceeded the manufacturer’s accuracy specification by not more than 0.005 feet.The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during distance-accuracy testing at the tested distances from 3 to 15 feet above the water surface at the HIF.

  3. Evaluation of Antiviral Activities of Four Local Malaysian Phyllanthus Species against Herpes Simplex Viruses and Possible Antiviral Target

    PubMed Central

    Tan, Wee Chee; Jaganath, Indu Bala; Manikam, Rishya; Sekaran, Shamala Devi

    2013-01-01

    Nucleoside analogues such as acyclovir are effective antiviral drugs against herpes simplex virus infections since its introduction. However, with the emergence of acyclovir-resistant HSV strains particularly in immunocompromised patients, there is a need to develop an alternative antiherpetic drug and plants could be the potential lead. In this study, the antiviral activity of the aqueous extract of four Phyllanthus species were evaluated against herpes simplex virus type-1 (HSV-1) and HSV-2 in Vero cells by quantitative PCR. The protein expressions of untreated and treated infected Vero cells were studied by 2D-gel electrophoresis and Western blot. This is the first study that reported the antiviral activity of P. watsonii. P. urinaria was shown to demonstrate the strongest antiviral activity against HSV-1 and HSV-2, with SI >33.6. Time-of-addition studies suggested that the extract may act against the early infection stage and the replication stage. Protein expression studies indicated that cellular proteins that are involved in maintaining cytoskeletal structure could be potential target for development of antiviral drugs. Preliminary findings indicated that P. urinaria demonstrated potent inhibitory activity against HSV. Hence, further studies such as in vivo evaluation are required for the development of effective antiherpetic drug. PMID:24324358

  4. Antiviral therapy: a perspective

    PubMed Central

    Shahidi Bonjar, Amir Hashem

    2016-01-01

    sufficient research has yielded positive results in animal models, EVAC could be used as a supportive treatment in humans along with conventional antiviral therapies. EVAC would not be suitable for all viral infections, but could be expected to decrease the casualties resulting from blood-borne viral infections. The EVAC approach would be efficient in terms of time, effort, and expenditure in the research and treatment of blood-borne viral infections. PMID:26893542

  5. Viral Ancestors of Antiviral Systems

    PubMed Central

    Villarreal, Luis P.

    2011-01-01

    All life must survive their corresponding viruses. Thus antiviral systems are essential in all living organisms. Remnants of virus derived information are also found in all life forms but have historically been considered mostly as junk DNA. However, such virus derived information can strongly affect host susceptibility to viruses. In this review, I evaluate the role viruses have had in the origin and evolution of host antiviral systems. From Archaea through bacteria and from simple to complex eukaryotes I trace the viral components that became essential elements of antiviral immunity. I conclude with a reexamination of the ‘Big Bang’ theory for the emergence of the adaptive immune system in vertebrates by horizontal transfer and note how viruses could have and did provide crucial and coordinated features. PMID:22069523

  6. Antivirals in the transplant setting.

    PubMed

    Griffiths, Paul D

    2006-09-01

    Over the past quarter of a century, antiviral drugs have moved from an experimental adventure in transplant patients to a situation where they are used routinely to prevent diseases caused by several viruses. Furthermore, they have significantly reduced several medical complications of transplantation, such as graft rejection, thereby implicating viruses as components of their pathogenesis. By controlling these major complication, the development of these antiviral drugs and their prodrugs, has therefore greatly facilitated the clinical expansion of transplantation, allowing life saving procedures to be offered to more patients who could potentially benefit. This article will briefly summaries which viruses are important following transplantation and outline the evidence-base from randomized controlled clinical trails for the deployment of antiviral drugs to prevent viral diseases.

  7. Viral ancestors of antiviral systems.

    PubMed

    Villarreal, Luis P

    2011-10-01

    All life must survive their corresponding viruses. Thus antiviral systems are essential in all living organisms. Remnants of virus derived information are also found in all life forms but have historically been considered mostly as junk DNA. However, such virus derived information can strongly affect host susceptibility to viruses. In this review, I evaluate the role viruses have had in the origin and evolution of host antiviral systems. From Archaea through bacteria and from simple to complex eukaryotes I trace the viral components that became essential elements of antiviral immunity. I conclude with a reexamination of the 'Big Bang' theory for the emergence of the adaptive immune system in vertebrates by horizontal transfer and note how viruses could have and did provide crucial and coordinated features.

  8. Carrier-Mediated Antiviral Therapy

    DTIC Science & Technology

    1988-01-01

    encapsulat- ed nbavirin (3 mg per mouse) on days 0 and 2. " %.. - V % % CARRIER- MEDIATED ANTIVIRAL THERAPY 245 Table 2. Effect or MTP-PE Treatment on the...illustrates the effect of IV MTP-PE on the survival of mice injected int’a- .. - ,.,.,.. nasally with HSV- 1 . A small but significant enhancement of...dosage of interferon was marginally effective when given in %%’. CARRIER- MEDIATED ANTIVIRAL THERAPY 251 only two or three injections (on days I and 6 or

  9. Novel antiviral activity of chemokines

    SciTech Connect

    Nakayama, Takashi; Shirane, Jumi; Hieshima, Kunio; Shibano, Michiko; Watanabe, Masayasu; Jin, Zhe; Nagakubo, Daisuke; Saito, Takuya; Shimomura, Yoshikazu; Yoshie, Osamu . E-mail: o.yoshie@med.kindai.ac.jp

    2006-07-05

    Antimicrobial peptides are a diverse family of small, mostly cationic polypeptides that kill bacteria, fungi and even some enveloped viruses, while chemokines are a group of mostly cationic small proteins that induce directed migration of leukocytes through interactions with a group of seven transmembrane G protein-coupled receptors. Recent studies have shown that antimicrobial peptides and chemokines have substantially overlapping functions. Thus, while some antimicrobial peptides are chemotactic for leukocytes, some chemokines can kill a wide range of bacteria and fungi. Here, we examined a possible direct antiviral activity of chemokines against an enveloped virus HSV-1. Among 22 human chemokines examined, chemokines such as MIP-1{alpha}/CCL3, MIP-1{beta}/CCL4 and RANTES/CCL5 showed a significant direct antiviral activity against HSV-1. It is intriguing that these chemokines are mostly known to be highly expressed by effector CD8{sup +} T cells. The chemokines with a significant anti-HSV-1 activity commonly bound to HSV-1 virions via envelope glycoprotein gB. Electron microscopy revealed that the chemokines with a significant anti-HSV-1 activity were commonly capable of generating pores in the envelope of HSV-1. Thus, some chemokines have a significant direct antiviral activity against HSV-1 in vitro and may have a potential role in host defense against HSV-1 as a direct antiviral agent.

  10. Optimization of Influenza Antiviral Response in Texas

    DTIC Science & Technology

    2015-03-01

    antiviral, vaccine , and social interventions. Mathematical models can guide policies to saves lives. In this thesis, we create an optimization model...and Prevention down to state and local regions, are prepared to respond to potential influenza pandemics with antiviral, vaccine , and social...model with vaccination and antivirals (V and T respectively) (from Coburn et al., 2009). .........................................................20

  11. AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM FUNICULOSUM

    PubMed Central

    Shope, Richard E.

    1966-01-01

    1. Helenine injected intraperitoneally 24 hr prior to a regularly fatal dose of Semliki Forest virus saves most of the mice to which it is administered. 2. Mice saved by helenine develop no viral immunity and regularly succumb when rechallenged 2 wk later with the same dose of virus from which they were originally saved. 3. The time during which helenine is optimally effective in protecting mice from death by Semliki Forest virus covers a period of approximately 36 hr beginning after about 12 hr and extending to 48 hr before virus infection. When periods of less than 12 hr, or more than 48 hr, elapse between the time of helenine administration and virus inoculation, its protective effectiveness diminishes progressively. 4. Repeated injections of helenine at 2- or 3-day intervals, if continued long enough, exhaust the capacity of a host to respond favorably to helenine administered 24 hr before virus inoculation. 5. Helenine injections at intervals of 4, 3, and 2 wk before its administration 24 hr prior to infection do not decrease the effectiveness of this final dose in protecting mice from fatal infection by the virus. The experimental results here reported indicate that, as suggested by the findings of earlier work, helenine does not act directly as an antiviral substance, but instead exerts its effect through some substance that it induces the host to elaborate. The nature of this induced antiviral substance is as yet unknown though, to judge from the failure of spared mice to acquire viral immunity, it appears to act at a stage in viral replication prior to that at which antigenic viral protein is produced. The findings with helenine and those thus far reported for interferon afford no factual basis for judging the relationship of the two, if any. PMID:5905239

  12. Antiviral silencing in animals.

    PubMed

    Li, Hong-Wei; Ding, Shou-Wei

    2005-10-31

    RNA silencing or RNA interference (RNAi) refers to the small RNA-guided gene silencing mechanism conserved in a wide range of eukaryotic organisms from plants to mammals. As part of this special issue on the biology, mechanisms and applications of RNAi, here we review the recent advances on defining a role of RNAi in the responses of invertebrate and vertebrate animals to virus infection. Approximately 40 miRNAs and 10 RNAi suppressors encoded by diverse mammalian viruses have been identified. Assays used for the identification of viral suppressors and possible biological functions of both viral miRNAs and suppressors are discussed. We propose that herpes viral miRNAs may act as specificity factors to initiate heterochromatin assembly of the latent viral DNA genome in the nucleus.

  13. Antiviral effect of mefloquine on feline calicivirus in vitro.

    PubMed

    McDonagh, Phillip; Sheehy, Paul A; Fawcett, Anne; Norris, Jacqueline M

    2015-04-17

    Feline calicivirus (FCV) is an important viral pathogen of domestic cats causing clinical signs ranging from mild to severe oral ulceration or upper respiratory tract disease through to a severe fatal systemic disease. Current therapeutic options are limited, with no direct acting antivirals available for treatment. This study screened a panel of 19 compounds for potential antiviral activity against FCV strain F9 and recent field isolates in vitro. Using a resazurin-based cytopathic effect (CPE) inhibition assay, mefloquine demonstrated a marked inhibitory effect on FCV induced CPE, albeit with a relatively low selectivity index. Orthogonal assays confirmed inhibition of CPE was associated with a significant reduction in viral replication. Mefloquine exhibited a strong inhibitory effect against a panel of seven recent FCV isolates from Australia, with calculated IC50 values for the field isolates approximately 50% lower than against the reference strain FCV F9. In vitro combination therapy with recombinant feline interferon-ω, a biological response modifier currently registered for the treatment of FCV, demonstrated additive effects with a concurrent reduction in the IC50 of mefloquine. These results are the first report of antiviral effects of mefloquine against a calicivirus and support further in vitro and in vivo evaluation of this compound as an antiviral therapeutic for FCV.

  14. Antiviral effect of lithium chloride.

    PubMed

    Cernescu, C; Popescu, L; Constantinescu, S; Cernescu, S

    1988-01-01

    Studies in human embryo fibroblasts infected with measles or herpes simplex virus showed a reduction in virus yield when cultures were pretreated with 1-10 mM lithium chloride doses. Maximum effect was obtained by a 1 h treatment with 10 mM lithium chloride, preceding viral infection by 19-24 hours. A specific antiviral effect against measles virus was manifest immediately after culture pretreatment. Intermittent treatment with 10 mM lithium chloride of cultures persistently infected with measles or herpes virus obtained from human myeloid K-562 cell line shows a reduction in the extracellular virus yield. In the K-562/herpes virus system, the culture treatment with lithium chloride and acyclovir (10 microM) has an additive inhibitory effect on virus production. The paper is focused on the mechanism of lithium chloride antiviral action and the expediency of lithium therapy in SSPE (subacute sclerosing panencephalitis).

  15. Henipavirus pathogenesis and antiviral approaches.

    PubMed

    Mathieu, Cyrille; Horvat, Branka

    2015-03-01

    Hendra virus and Nipah virus are closely related, recently emerged zoonotic paramyxoviruses, belonging to the Henipavirus genus. Both viruses induce generalized vasculitis affecting particularly the respiratory tract and CNS. The exceptionally broad species tropism of Henipavirus, the high case fatality rate and person-to-person transmission associated with Nipah virus outbreaks emphasize the necessity of effective antiviral strategies for these intriguing threatening pathogens. Current therapeutic approaches, validated in animal models, target early steps in viral infection; they include the use of neutralizing virus-specific antibodies and blocking membrane fusion with peptides that bind the viral fusion protein. A better understanding of Henipavirus pathogenesis is critical for the further advancement of antiviral treatment, and we summarize here the recent progress in the field.

  16. Alteration of Antiviral Signalling by Single Nucleotide Polymorphisms (SNPs) of Mitochondrial Antiviral Signalling Protein (MAVS)

    PubMed Central

    Xing, Fei; Matsumiya, Tomoh; Hayakari, Ryo; Yoshida, Hidemi; Kawaguchi, Shogo; Takahashi, Ippei; Nakaji, Shigeyuki; Imaizumi, Tadaatsu

    2016-01-01

    Genetic variation is associated with diseases. As a type of genetic variation occurring with certain regularity and frequency, the single nucleotide polymorphism (SNP) is attracting more and more attention because of its great value for research and real-life application. Mitochondrial antiviral signalling protein (MAVS) acts as a common adaptor molecule for retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), which can recognize foreign RNA, including viral RNA, leading to the induction of type I interferons (IFNs). Therefore, MAVS is thought to be a crucial molecule in antiviral innate immunity. We speculated that genetic variation of MAVS may result in susceptibility to infectious diseases. To assess the risk of viral infection based on MAVS variation, we tested the effects of twelve non-synonymous MAVS coding-region SNPs from the National Center for Biotechnology Information (NCBI) database that result in amino acid substitutions. We found that five of these SNPs exhibited functional alterations. Additionally, four resulted in an inhibitory immune response, and one had the opposite effect. In total, 1,032 human genomic samples obtained from a mass examination were genotyped at these five SNPs. However, no homozygous or heterozygous variation was detected. We hypothesized that these five SNPs are not present in the Japanese population and that such MAVS variations may result in serious immune diseases. PMID:26954674

  17. Antiviral effects of Glycyrrhiza species.

    PubMed

    Fiore, Cristina; Eisenhut, Michael; Krausse, Rea; Ragazzi, Eugenio; Pellati, Donatella; Armanini, Decio; Bielenberg, Jens

    2008-02-01

    Historical sources for the use of Glycyrrhiza species include ancient manuscripts from China, India and Greece. They all mention its use for symptoms of viral respiratory tract infections and hepatitis. Randomized controlled trials confirmed that the Glycyrrhiza glabra derived compound glycyrrhizin and its derivatives reduced hepatocellular damage in chronic hepatitis B and C. In hepatitis C virus-induced cirrhosis the risk of hepatocellular carcinoma was reduced. Animal studies demonstrated a reduction of mortality and viral activity in herpes simplex virus encephalitis and influenza A virus pneumonia. In vitro studies revealed antiviral activity against HIV-1, SARS related coronavirus, respiratory syncytial virus, arboviruses, vaccinia virus and vesicular stomatitis virus. Mechanisms for antiviral activity of Glycyrrhiza spp. include reduced transport to the membrane and sialylation of hepatitis B virus surface antigen, reduction of membrane fluidity leading to inhibition of fusion of the viral membrane of HIV-1 with the cell, induction of interferon gamma in T-cells, inhibition of phosphorylating enzymes in vesicular stomatitis virus infection and reduction of viral latency. Future research needs to explore the potency of compounds derived from licorice in prevention and treatment of influenza A virus pneumonia and as an adjuvant treatment in patients infected with HIV resistant to antiretroviral drugs.

  18. Oligonucleotide-based antiviral strategies.

    PubMed

    Schubert, S; Kurreck, J

    2006-01-01

    In the age of extensive global traffic systems, the close neighborhood of man and livestock in some regions of the world, as well as inadequate prevention measures and medical care in poorer countries, greatly facilitates the emergence and dissemination of new virus strains. The appearance of avian influenza viruses that can infect humans, the spread of the severe acute respiratory syndrome (SARS) virus, and the unprecedented raging of human immunodeficiency virus (HIV) illustrate the threat of a global virus pandemic. In addition, viruses like hepatitis B and C claim more than one million lives every year for want of efficient therapy. Thus, new approaches to prevent virus propagation are urgently needed. Antisense strategies are considered a very attractive means of inhibiting viral replication, as oligonucleotides can be designed to interact with any viral RNA, provided its sequence is known. The ensuing targeted destruction of viral RNA should interfere with viral replication without entailing negative effects on ongoing cellular processes. In this review, we will give some examples of the employment of antisense oligonucleotides, ribozymes, and RNA interference strategies for antiviral purposes. Currently, in spite of encouraging results in preclinical studies, only a few antisense oligonucleotides and ribozymes have turned out to be efficient antiviral compounds in clinical trials. The advent of RNA interference now seems to be refueling hopes for decisive progress in the field of therapeutic employment of antisense strategies.

  19. What You Should Know about Flu Antiviral Drugs

    MedlinePlus

    ... Newsletters What You Should Know About Flu Antiviral Drugs Language: English Español Recommend on Facebook Tweet ... used to treat flu illness. What are antiviral drugs? Antiviral drugs are prescription medicines (pills, liquid, an ...

  20. Broad-spectrum antivirals against viral fusion

    PubMed Central

    Vigant, Frederic; Santos, Nuno C.; Lee, Benhur

    2015-01-01

    Effective antivirals have been developed against specific viruses, such as HIV, Hepatitis C virus and influenza virus. This ‘one bug–one drug’ approach to antiviral drug development can be successful, but it may be inadequate for responding to an increasing diversity of viruses that cause significant diseases in humans. The majority of viral pathogens that cause emerging and re-emerging infectious diseases are membrane-enveloped viruses, which require the fusion of viral and cell membranes for virus entry. Therefore, antivirals that target the membrane fusion process represent new paradigms for broad-spectrum antiviral discovery. In this Review, we discuss the mechanisms responsible for the fusion between virus and cell membranes and explore how broad-spectrum antivirals target this process to prevent virus entry. PMID:26075364

  1. Probiotics as antiviral agents in shrimp aquaculture.

    PubMed

    Lakshmi, Bestha; Viswanath, Buddolla; Sai Gopal, D V R

    2013-01-01

    Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases.

  2. Probiotics as Antiviral Agents in Shrimp Aquaculture

    PubMed Central

    Lakshmi, Bestha; Sai Gopal, D. V. R.

    2013-01-01

    Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases. PMID:23738078

  3. IFN-λ determines the intestinal epithelial antiviral host defense

    PubMed Central

    Pott, Johanna; Mahlakõiv, Tanel; Mordstein, Markus; Duerr, Claudia U.; Michiels, Thomas; Stockinger, Silvia; Staeheli, Peter; Hornef, Mathias W.

    2011-01-01

    Type I and type III IFNs bind to different cell-surface receptors but induce identical signal transduction pathways, leading to the expression of antiviral host effector molecules. Despite the fact that type III IFN (IFN-λ) has been shown to predominantly act on mucosal organs, in vivo infection studies have failed to attribute a specific, nonredundant function. Instead, a predominant role of type I IFN was observed, which was explained by the ubiquitous expression of the type I IFN receptor. Here we comparatively analyzed the role of functional IFN-λ and type I IFN receptor signaling in the innate immune response to intestinal rotavirus infection in vivo, and determined viral replication and antiviral gene expression on the cellular level. We observed that both suckling and adult mice lacking functional receptors for IFN-λ were impaired in the control of oral rotavirus infection, whereas animals lacking functional receptors for type I IFN were similar to wild-type mice. Using Mx1 protein accumulation as marker for IFN responsiveness of individual cells, we demonstrate that intestinal epithelial cells, which are the prime target cells of rotavirus, strongly responded to IFN-λ but only marginally to type I IFN in vivo. Systemic treatment of suckling mice with IFN-λ repressed rotavirus replication in the gut, whereas treatment with type I IFN was not effective. These results are unique in identifying a critical role of IFN-λ in the epithelial antiviral host defense. PMID:21518880

  4. Mechanisms of antiviral action of plant antimicrobials against murine norovirus.

    PubMed

    Gilling, Damian H; Kitajima, Masaaki; Torrey, Jason R; Bright, Kelly R

    2014-08-01

    Numerous plant compounds have antibacterial or antiviral properties; however, limited research has been conducted with nonenveloped viruses. The efficacies of allspice oil, lemongrass oil, and citral were evaluated against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. The antiviral mechanisms of action were also examined using an RNase I protection assay, a host cell binding assay, and transmission electron microscopy. All three antimicrobials produced significant reductions (P ≤ 0.05) in viral infectivity within 6 h of exposure (0.90 log10 to 1.88 log10). After 24 h, the reductions were 2.74, 3.00, and 3.41 log10 for lemongrass oil, citral, and allspice oil, respectively. The antiviral effect of allspice oil was both time and concentration dependent; the effects of lemongrass oil and citral were time dependent. Based on the RNase I assay, allspice oil appeared to act directly upon the viral capsid and RNA. The capsids enlarged from ≤ 35 nm to up to 75 nm following treatment. MNV adsorption to host cells was not significantly affected. Alternatively, the capsid remained intact following exposure to lemongrass oil and citral, which appeared to coat the capsid, causing nonspecific and nonproductive binding to host cells that did not lead to successful infection. Such contrasting effects between allspice oil and both lemongrass oil and citral suggest that though different plant compounds may yield similar reductions in virus infectivity, the mechanisms of inactivation may be highly varied and specific to the antimicrobial. This study demonstrates the antiviral properties of allspice oil, lemongrass oil, and citral against MNV and thus indicates their potential as natural food and surface sanitizers to control noroviruses.

  5. Mechanisms of Antiviral Action of Plant Antimicrobials against Murine Norovirus

    PubMed Central

    Gilling, Damian H.; Kitajima, Masaaki; Torrey, Jason R.

    2014-01-01

    Numerous plant compounds have antibacterial or antiviral properties; however, limited research has been conducted with nonenveloped viruses. The efficacies of allspice oil, lemongrass oil, and citral were evaluated against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. The antiviral mechanisms of action were also examined using an RNase I protection assay, a host cell binding assay, and transmission electron microscopy. All three antimicrobials produced significant reductions (P ≤ 0.05) in viral infectivity within 6 h of exposure (0.90 log10 to 1.88 log10). After 24 h, the reductions were 2.74, 3.00, and 3.41 log10 for lemongrass oil, citral, and allspice oil, respectively. The antiviral effect of allspice oil was both time and concentration dependent; the effects of lemongrass oil and citral were time dependent. Based on the RNase I assay, allspice oil appeared to act directly upon the viral capsid and RNA. The capsids enlarged from ≤35 nm to up to 75 nm following treatment. MNV adsorption to host cells was not significantly affected. Alternatively, the capsid remained intact following exposure to lemongrass oil and citral, which appeared to coat the capsid, causing nonspecific and nonproductive binding to host cells that did not lead to successful infection. Such contrasting effects between allspice oil and both lemongrass oil and citral suggest that though different plant compounds may yield similar reductions in virus infectivity, the mechanisms of inactivation may be highly varied and specific to the antimicrobial. This study demonstrates the antiviral properties of allspice oil, lemongrass oil, and citral against MNV and thus indicates their potential as natural food and surface sanitizers to control noroviruses. PMID:24907316

  6. Antiviral Perspectives for Chikungunya Virus

    PubMed Central

    Cherian, Sarah

    2014-01-01

    Chikungunya virus (CHIKV) is a mosquito-borne pathogen that has a major health impact in humans and causes acute febrile illness in humans accompanied by joint pains and, in many cases, persistent arthralgia lasting for weeks to years. CHIKV reemerged in 2005-2006 in several parts of the Indian Ocean islands and India after a gap of 32 years, causing millions of cases. The re-emergence of CHIKV has also resulted in numerous outbreaks in several countries in the eastern hemisphere, with a threat to further expand in the near future. However, there is no vaccine against CHIKV infection licensed for human use, and therapy for CHIKV infection is still mainly limited to supportive care as antiviral agents are yet in different stages of testing or development. In this review we explore the different perspectives for chikungunya treatment and the effectiveness of these treatment regimens and discuss the scope for future directions. PMID:24955364

  7. 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.

  8. 75 FR 16810 - Determination and Declarations Regarding Emergency Use of Certain In vitro Diagnostic, Antiviral...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... determined that a public health emergency exists nationwide involving Swine Influenza A (now known as 2009 H1N1 Influenza A, or 2009 H1N1 Influenza) that affects or has significant potential to affect national... under the Public Readiness and Emergency Preparedness (PREP) Act for Influenza Antivirals...

  9. The antiviral activity of arctigenin in traditional Chinese medicine on porcine circovirus type 2.

    PubMed

    Chen, Jie; Li, Wentao; Jin, Erguang; He, Qigai; Yan, Weidong; Yang, Hanchun; Gong, Shiyu; Guo, Yi; Fu, Shulin; Chen, Xiabing; Ye, Shengqiang; Qian, Yunguo

    2016-06-01

    Arctigenin (ACT) is a phenylpropanoid dibenzylbutyrolactone lignan extracted from the traditional herb Arctium lappa L. (Compositae) with anti-viral and anti-inflammatory effects. Here, we investigated the antiviral activity of ACT found in traditional Chinese medicine on porcine circovirus type 2 (PCV2) in vitro and in vivo. Results showed that dosing of 15.6-62.5μg/mL ACT could significantly inhibit the PCV2 proliferation in PK-15 cells (P<0.01). Dosing of 62.5μg/mL ACT 0, 4 or 8h after challenge inoculation significantly inhibited the proliferation of 1MOI and 10MOI in PK-15 cells (P<0.01), and the inhibitory effect of ACT dosing 4h or 8h post-inoculation was greater than 0h after dosing (P<0.01). In vivo test with mice challenge against PCV2 infection demonstrated that intraperitoneal injection of 200μg/kg ACT significantly inhibited PCV2 proliferation in the lungs, spleens and inguinal lymph nodes, with an effect similar to ribavirin, demonstrating the effectiveness of ACT as an antiviral agent against PCV2 in vitro and in vivo. This compound, therefore, may have the potential to serve as a drug for protection of pigs against the infection of PCV2.

  10. Antiviral Natural Products and Herbal Medicines

    PubMed Central

    Lin, Liang-Tzung; Hsu, Wen-Chan; Lin, Chun-Ching

    2014-01-01

    Viral infections play an important role in human diseases, and recent outbreaks in the advent of globalization and ease of travel have underscored their prevention as a critical issue in safeguarding public health. Despite the progress made in immunization and drug development, many viruses lack preventive vaccines and efficient antiviral therapies, which are often beset by the generation of viral escape mutants. Thus, identifying novel antiviral drugs is of critical importance and natural products are an excellent source for such discoveries. In this mini-review, we summarize the antiviral effects reported for several natural products and herbal medicines. PMID:24872930

  11. Antiviral treatment of influenza in South Korea.

    PubMed

    Choe, Young June; Lee, Hyunju; Lee, Hoan Jong; Choi, Eun Hwa

    2015-06-01

    Antiviral therapy has an important role in the treatment and chemoprophylaxis of influenza. At present, two classes of antiviral agents, adamantanes and neuraminidase inhibitors, are available for the treatment and chemoprophylaxis of influenza in Korea. Because of the widespread resistance against adamantanes, neuraminidase inhibitors are mainly used. Because each country has a unique epidemiology of influenza, the proper use of antiviral agents should be determined based on local data. Decisions on the clinical practice in the treatment of influenza in South Korea are guided by the local surveillance data, practice guidelines, health insurance system and the resistance patterns of the circulating influenza viruses. This review highlights the role of antiviral agents in the treatment and outcome of influenza in Korea by providing comprehensive information of their clinical usage in Korea.

  12. Developing Novel Antimicrobial and Antiviral Textile Products.

    PubMed

    Iyigundogdu, Zeynep Ustaoglu; Demir, Okan; Asutay, Ayla Burcin; Sahin, Fikrettin

    2017-03-01

    In conjunction with an increasing public awareness of infectious diseases, the textile industry and scientists are developing hygienic fabrics by the addition of various antimicrobial and antiviral compounds. In the current study, sodium pentaborate pentahydrate and triclosan are applied to cotton fabrics in order to gain antimicrobial and antiviral properties for the first time. The antimicrobial activity of textiles treated with 3 % sodium pentaborate pentahydrate, 0.03 % triclosan, and 7 % Glucapon has been investigated against a broad range of microorganisms including bacteria, yeast, and fungi. Moreover, modified cotton fabrics were tested against adenovirus type 5 and poliovirus type 1. According to the test results, the modified textile goods attained very good antimicrobial and antiviral properties. Thus, the results of the present study clearly suggest that sodium pentaborate pentahydrate and triclosan solution-treated textiles can be considered in the development of antimicrobial and antiviral textile finishes.

  13. Fluorinated nucleosides as antiviral and antitumor agents.

    PubMed

    Meng, Wei-Dong; Qing, Feng-Ling

    2006-01-01

    The synthesis of nucleosides and analogues with fluoride modifications on the surgar moiety are reviewed, and their biological activities as potential antiviral and anti-tumor agents are also discussed.

  14. Antiviral Drugs: Molecular Modeling and QSAR.

    DTIC Science & Technology

    1990-12-10

    questions related to drug design and our areas of expertise; (3) provide general education to USAMRII)D personnel in our methods and capabilities. In...terms of drug design effort, the antiviral drug development effortat US AMRIrID is in its infancy. Little is known of the structure or biology of the...because of the dearth of information about the viruses, for the antiviral work this approach to drug design is currently unavailable to USAMRIID and to

  15. Antiviral symposium and workshop--eighth international meeting.

    PubMed

    Schang, L

    2001-02-01

    The invited speakers for this exciting meeting could be loosely classified into three categories: (i) pre-eminent academic researchers on antivirals; (ii) academic researchers working on basic aspects of virology but whose work may lead to the development of novel antivirals; and, (iii) academic clinicians working with experimental antivirals or with diseases that require new antivirals. As expected from this selection, this meeting explored the future of antivirals, while still paying attention to the development of improved derivatives of currently available drugs.

  16. Guidance for clinical and public health laboratories testing for influenza virus antiviral drug susceptibility in Europe.

    PubMed

    Pozo, Francisco; Lina, Bruno; Andrade, Helena Rebelo de; Enouf, Vincent; Kossyvakis, Athanasios; Broberg, Eeva; Daniels, Rod; Lackenby, Angie; Meijer, Adam

    2013-05-01

    Two classes of antiviral drugs are licensed in Europe for treatment and prophylaxis of influenza; the M2 ion-channel blockers amantadine and rimantadine acting against type A influenza viruses only and the neuraminidase enzyme inhibitors zanamivir and oseltamivir acting against type A and type B influenza viruses. This guidance document was developed for but not limited to the European Union (EU) and other European Economic Area (EEA) countries on how and when to test for influenza virus antiviral drug susceptibility. It is aimed at clinical and influenza surveillance laboratories carrying out antiviral drug susceptibility testing on influenza viruses from patients suspected of harbouring viruses with reduced susceptibility or for the monitoring of the emergence of such among circulating viruses, respectively. Therefore, the guidance should not be read as a directive or an algorithm for treatment. Monitoring for emergence of influenza viruses with reduced drug susceptibility in hospitalized cases is crucial for decision making on possible changes to antiviral treatment. Therefore, it is important to test for antiviral susceptibility in certain patient groups, such as patients treated with influenza antiviral drugs. It is also important to determine the frequency of viruses with natural (not related to drug use) reduced susceptibility among community and hospitalized cases, as this knowledge is essential for making empirical antiviral treatment decisions. Furthermore, testing of specimens from community influenza patients is needed to determine the frequency of viruses with reduced susceptibility and good viral fitness that are readily transmissible, as they may become dominant among circulating viruses. Phenotypic neuraminidase enzyme inhibition assays are recommended to determine the level of inhibition of the neuraminidase enzyme by antiviral drugs as a measure of drug susceptibility of the virus. Genotypic assays are recommended to identify amino acid

  17. Divergent antiviral effects of bioflavonoids on the hepatitis C virus life cycle

    SciTech Connect

    Khachatoorian, Ronik; Arumugaswami, Vaithilingaraja; Raychaudhuri, Santanu; Yeh, George K.; Maloney, Eden M.; Wang, Julie; and others

    2012-11-25

    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 an 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.

  18. Advances in Antiviral vaccine development

    PubMed Central

    Graham, Barney S.

    2013-01-01

    Summary Antiviral vaccines have been the most successful biomedical intervention for preventing epidemic viral disease. Vaccination for smallpox in humans and rinderpest in cattle was the basis for disease eradication, and recent progress in polio eradication is promising. While early vaccines were developed empirically by passage in live animals or eggs, more recent vaccines have been developed because of the advent of new technologies, particularly cell culture and molecular biology. Recent technological advances in gene delivery and expression, nanoparticles, protein manufacturing, and adjuvants have created the potential for new vaccine platforms that may provide solutions for vaccines against viral pathogens for which no interventions currently exist. In addition, the technological convergence of human monoclonal antibody isolation, structural biology, and high throughput sequencing is providing new opportunities for atomic-level immunogen design. Selection of human monoclonal antibodies can identify immunodominant antigenic sites associated with neutralization and provide reagents for stabilizing and solving the structure of viral surface proteins. Understanding the structural basis for neutralization can guide selection of vaccine targets. Deep sequencing of the antibody repertoire and defining the ontogeny of the desired antibody responses can reveal the junctional recombination and somatic mutation requirements for B-cell recognition and affinity maturation. Collectively, this information will provide new strategic approaches for selecting vaccine antigens, formulations, and regimens. Moreover, it creates the potential for rational vaccine design and establishing a catalogue of vaccine technology platforms that would be effective against any given family or class of viral pathogens and improve our readiness to address new emerging viral threats. PMID:23947359

  19. Addressing the Challenges of Hepatitis C Virus Resistance and Treatment Failure.

    PubMed

    Colpitts, Che C; Baumert, Thomas F

    2016-08-16

    Chronic hepatitis C is a major cause of chronic liver disease, including liver cirrhosis and hepatocellular carcinoma. The development of direct-acting antivirals (DAAs) revolutionized hepatitis C virus (HCV) treatment by offering genuine prospects for the first comprehensive cure of a chronic viral infection in humans. While antiviral resistance is a significant limitation for interferon-based therapies, resistance and treatment failure still appear to be present in a small fraction of patients even in state-of-the-art DAA combination therapies. Therefore, treatment failure and resistance still remain a clinical challenge for the management of patients not responding to DAAs. In this special issue of Viruses on HCV drug resistance, mechanisms of antiviral resistance for different classes of antiviral drugs are described. Furthermore, the detection and monitoring of resistance in clinical practice, the clinical impact of resistance in different patient groups and strategies to prevent and address resistance and treatment failure using complementary antiviral strategies are reviewed.

  20. 18th International Conference on Antiviral Research.

    PubMed

    Mitchell, William M

    2005-08-01

    The 18th International Conference on Antiviral Research (ICAR) was held at the Princess Sofia Hotel in Barcelona, Spain, from 11th-14th April, 2005. This is a yearly international meeting sponsored by the International Society for Antiviral Research (ISAR). The current president of ISAR is John A Secrest 3rd of the Southern Research Institute. The scientific programme committee was chaired by John C Drach from the University of Michigan. ISAR was founded in 1987 to exchange prepublication basic, applied and clinical information on the development of antiviral, chemical and biological agents as well as to promote collaborative research. The ISAR has had a major role in the significant advances of the past decade in the reduction of the societal burdens of viral diseases by the focus of ICAR on the discovery and clinical application of antiviral agents. The 18th ICAR was organised as a series of focus presentations on specific viral groups consisting of oral and poster presentations of original research findings. In addition, the conference included plenary speakers, award presentations, a minisymposium on bioterrorism, and a satellite symposium on clinical antiviral drug developments. The size of the conference (> 50 oral and 250 poster presentations) necessitates limitation to the most noteworthy in the judgment of this reviewer. The current membership of the ISAR is approximately 700 with approximately 50% the membership in attendance.

  1. Antiviral activities of heated dolomite powder.

    PubMed

    Motoike, Koichi; Hirano, Shozo; Yamana, Hideaki; Onda, Tetsuhiko; Maeda, Takayoshi; Ito, Toshihiro; Hayakawa, Motozo

    2008-12-01

    The effect of the heating conditions of dolomite powder on its antiviral activity was studied against the H5N3 avian influenza virus. Calcium oxide (CaO) and magnesium oxide (MgO), obtained by the thermal decomposition of dolomite above 800 degrees C, were shown to have strong antiviral activity, but the effect was lessened when the heating temperature exceeded 1400 degrees C. Simultaneous measurement of the crystallite size suggested that the weakening of the activity was due to the considerable grain growth of the oxides. It was found that the presence of Mg in dolomite contributed to the deterrence of grain growth of the oxides during the heating process. Although both CaO and MgO exhibited strong antiviral activity, CaO had the stronger activity but quickly hydrated in the presence of water. On the other hand, the hydration of MgO took place gradually under the same conditions. Separate measurements using MgO and Mg(OH)2 revealed that MgO had a higher antiviral effect than Mg(OH)2. From the overall experiments, it was suggested that the strong antiviral activity of dolomite was related to the hydration reaction of CaO.

  2. Antiviral Defense Mechanisms in Honey Bees

    PubMed Central

    Brutscher, Laura M.; Daughenbaugh, Katie F.; Flenniken, Michelle L.

    2015-01-01

    Honey bees are significant pollinators of agricultural crops and other important plant species. High annual losses of honey bee colonies in North America and in some parts of Europe have profound ecological and economic implications. Colony losses have been attributed to multiple factors including RNA viruses, thus understanding bee antiviral defense mechanisms may result in the development of strategies that mitigate colony losses. Honey bee antiviral defense mechanisms include RNA-interference, pathogen-associated molecular pattern (PAMP) triggered signal transduction cascades, and reactive oxygen species generation. However, the relative importance of these and other pathways is largely uncharacterized. Herein we review the current understanding of honey bee antiviral defense mechanisms and suggest important avenues for future investigation. PMID:26273564

  3. Gene Expression Signature-Based Screening Identifies New Broadly Effective Influenza A Antivirals

    PubMed Central

    Josset, Laurence; Textoris, Julien; Loriod, Béatrice; Ferraris, Olivier; Moules, Vincent; Lina, Bruno; N'Guyen, Catherine; Diaz, Jean-Jacques; Rosa-Calatrava, Manuel

    2010-01-01

    Classical antiviral therapies target viral proteins and are consequently subject to resistance. To counteract this limitation, alternative strategies have been developed that target cellular factors. We hypothesized that such an approach could also be useful to identify broad-spectrum antivirals. The influenza A virus was used as a model for its viral diversity and because of the need to develop therapies against unpredictable viruses as recently underlined by the H1N1 pandemic. We proposed to identify a gene-expression signature associated with infection by different influenza A virus subtypes which would allow the identification of potential antiviral drugs with a broad anti-influenza spectrum of activity. We analyzed the cellular gene expression response to infection with five different human and avian influenza A virus strains and identified 300 genes as differentially expressed between infected and non-infected samples. The most 20 dysregulated genes were used to screen the connectivity map, a database of drug-associated gene expression profiles. Candidate antivirals were then identified by their inverse correlation to the query signature. We hypothesized that such molecules would induce an unfavorable cellular environment for influenza virus replication. Eight potential antivirals including ribavirin were identified and their effects were tested in vitro on five influenza A strains. Six of the molecules inhibited influenza viral growth. The new pandemic H1N1 virus, which was not used to define the gene expression signature of infection, was inhibited by five out of the eight identified molecules, demonstrating that this strategy could contribute to identifying new broad anti-influenza agents acting on cellular gene expression. The identified infection signature genes, the expression of which are modified upon infection, could encode cellular proteins involved in the viral life cycle. This is the first study showing that gene expression-based screening can be

  4. Antiviral therapy: current concepts and practices.

    PubMed Central

    Bean, B

    1992-01-01

    Drugs capable of inhibiting viruses in vitro were described in the 1950s, but real progress was not made until the 1970s, when agents capable of inhibiting virus-specific enzymes were first identified. The last decade has seen rapid progress in both our understanding of antiviral therapy and the number of antiviral agents on the market. Amantadine and ribavirin are available for treatment of viral respiratory infections. Vidarabine, acyclovir, ganciclovir, and foscarnet are used for systemic treatment of herpesvirus infections, while ophthalmic preparations of idoxuridine, trifluorothymidine, and vidarabine are available for herpes keratitis. For treatment of human immunodeficiency virus infections, zidovudine and didanosine are used. Immunomodulators, such as interferons and colony-stimulating factors, and immunoglobulins are being used increasingly for viral illnesses. While resistance to antiviral drugs has been seen, especially among AIDS patients, it has not become widespread and is being intensely studied. Increasingly, combinations of agents are being used: to achieve synergistic inhibition of viruses, to delay or prevent resistance, and to decrease dosages of toxic drugs. New approaches, such as liposomes carrying antiviral drugs and computer-aided drug design, are exciting and promising prospects for the future. PMID:1576586

  5. Interferon induced IFIT family genes in host antiviral defense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Secretion of interferons (IFNs) from virus-infected cells is a hallmark of host antiviral immunity and in fact, IFNs exert their antiviral activities through the induction of antiviral proteins. The IFN-induced protein with tetratricopeptide repeats (IFITs) family is among hundreds of IF stimulated ...

  6. Demonstration Advanced Avionics System (DAAS)

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The feasibility of developing an integrated avionics system suitable for general aviation was determined. A design of reliable integrated avionics which provides expanded functional capability that significantly enhances the utility and safety of general aviation at a cost commensurate with the general aviation market was developed. The use of a data bus, microprocessors, electronic displays and data entry devices, and improved function capabilities were emphasized. An avionics system capable of evaluating the most critical and promising elements of an integrated system was designed, built and flight tested in a twin engine general aviation aircraft.

  7. DAAS: Defense Automatic Addressing System.

    DTIC Science & Technology

    1985-04-01

    Optional Development. flOSS can be provided in the following two ways: a. Potential Scbscribers Use of Existing ADP System. If the PW country has an...series. (1) Features of the Turnkea estem. This menu driven system provides for easy system operation aW initial training. Another feature of the turnkey

  8. Homologous RIG-I–like helicase proteins direct RNAi-mediated antiviral immunity in C. elegans by distinct mechanisms

    PubMed Central

    Guo, Xunyang; Zhang, Rui; Wang, Jeffrey; Ding, Shou-Wei; Lu, Rui

    2013-01-01

    RNAi-mediated antiviral immunity in Caenorhabditis elegans requires Dicer-related helicase 1 (DRH-1), which encodes the helicase and C-terminal domains homologous to the mammalian retinoic acid inducible gene I (RIG-I)-like helicase (RLH) family of cytosolic immune receptors. Here we show that the antiviral function of DRH-1 requires the RIG-I homologous domains as well as its worm-specific N-terminal domain. We also demonstrate that the helicase and C-terminal domains encoded by either worm DRH-2 or human RIG-I can functionally replace the corresponding domains of DRH-1 to mediate antiviral RNAi in C. elegans. Notably, substitutions in a three-residue motif of the C-terminal regulatory domain of RIG-I that physically interacts with viral double-stranded RNA abolish the antiviral activity of C-terminal regulatory domains of both RIG-I and DRH-1 in C. elegans. Genetic analysis revealed an essential role for both DRH-1 and DRH-3 in C. elegans antiviral RNAi targeting a natural viral pathogen. However, Northern blot and small RNA deep sequencing analyses indicate that DRH-1 acts to enhance production of viral primary siRNAs, whereas DRH-3 regulates antiviral RNAi by participating in the biogenesis of secondary siRNAs after Dicer-dependent production of primary siRNAs. We propose that DRH-1 facilitates the acquisition of viral double-stranded RNA by the worm dicing complex for the subsequent processing into primary siRNAs. The strong parallel for the antiviral function of RLHs in worms and mammals suggests that detection of viral double-stranded RNA may activate completely unrelated effector mechanisms or, alternatively, that the mammalian RLHs have a conserved activity to stimulate production of viral siRNAs for antiviral immunity by an RNAi effector mechanism. PMID:24043766

  9. Antiviral properties of quinolone-based drugs.

    PubMed

    Richter, Sara; Parolin, Cristina; Palumbo, Manlio; Palù, Giorgio

    2004-06-01

    Quinolones represent an important class of broad-spectrum antibacterials, the main structural features of which are a 1,4 dihydro-4-oxo-quinolinyl moiety bearing an essential carboxyl group at position 3. Quinolones inhibit prokaryotic type II topoisomerases, namely DNA gyrase and, in a few cases, topoisomerase IV, through direct binding to the bacterial chromosome. Based on the hypothesis that these drugs could also bind to the viral nucleic acids or nucleoprotein-complexes, several quinolone derivatives were tested for their antiviral activity. Indeed, antibacterial fluoroquinolones were shown to be effective against vaccinia virus and papovaviruses; these preliminary results prompted the synthesis of modified quinolones to optimize antiviral action and improve selectivity index. The introduction of an aryl group at the piperazine moiety of the fluoroquinolone shifted the activity from antibacterial to antiviral, with a specific action against HIV. The antiviral activity seemed to be related to an inhibitory effect at the transcriptional level, and further evidence suggested a mechanism of action mediated by inhibition of Tat functions. Substitution of the fluorine at position 6 with an amine group to give aryl-piperazinyl-6-amino-quinolones improved the activity and selectivity against HIV-1: the most potent compound of this series was shown to inhibit virus replication through interference with Tat-TAR interaction. A comprehensive SAR investigation was performed based on additional chemical intervention to the quinolone template moiety, such as the introduction of nucleoside derivative functions. The information gained so far will be useful for future rational drug design aimed at developing new compounds with optimized antiviral activity.

  10. 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

  11. The Barrier to Autointegration Factor: Interlocking Antiviral Defense with Genome Maintenance

    PubMed Central

    Jamin, Augusta

    2016-01-01

    Intrinsic defenses targeting foreign DNA are one facet of the cellular armament tasked with protecting host genomic integrity. The DNA binding protein BAF (barrier to autointegration factor) contributes to multiple aspects of genome maintenance and intercepts retrovirus, poxvirus, and herpesvirus genomes during infection. In this gem, we discuss the unique position BAF occupies at the virus-host interface and how both viral and cellular mechanisms may regulate its capacity to act as a pro- or antiviral effector targeting viral DNA. PMID:26842478

  12. The Barrier to Autointegration Factor: Interlocking Antiviral Defense with Genome Maintenance.

    PubMed

    Wiebe, Matthew S; Jamin, Augusta

    2016-04-01

    Intrinsic defenses targeting foreign DNA are one facet of the cellular armament tasked with protecting host genomic integrity. The DNA binding protein BAF (barrier to autointegration factor) contributes to multiple aspects of genome maintenance and intercepts retrovirus, poxvirus, and herpesvirus genomes during infection. In this gem, we discuss the unique position BAF occupies at the virus-host interface and how both viral and cellular mechanisms may regulate its capacity to act as a pro- or antiviral effector targeting viral DNA.

  13. Pushing to a cure by harnessing innate immunity against hepatitis C virus.

    PubMed

    Ireton, Reneé C; Gale, Michael

    2014-08-01

    Hepatitis C virus (HCV) causes 350,000 deaths and infects at least 3million people worldwide every year. Currently no vaccine has been developed. Direct-acting antiviral (DAA) drugs with high efficacy for suppressing HCV infection have recently been introduced into the clinic. While DAAs initially required combination therapy with type-1 interferon (IFN) administration for full efficacy and to avoid viral resistance to treatment, new DAA combinations show promise as an IFN-free regimen. However, IFN-free DAA therapy is in its infancy, still to be proven and today is cost-prohibitive for the patient. A major goal in HCV therapy to remove or replace IFN with DAAs or an alternative therapeutic to render virologic response with continued virus sensitivity to DAAs, thus facilitating a cure for infection. Recent advances in our understanding of innate immune responses to HCV have identified new therapeutic targets to combat HCV infection. We discuss how the targeting of innate immune response factors can be harnessed with DAAs to produce new generations of DAA-based HCV therapeutics. This article forms part of a symposium in Antiviral Research on "Hepatitis C: next steps toward global eradication."

  14. 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

  15. [Current management of hepatitis C].

    PubMed

    Lange, Christian M

    2015-09-01

    During the last decade, the therapeutic management of hepatitis C virus (HCV) infection has changed dramatically. Due to the recent approval of several directly acting antiviral agents (DAAs) such as sofosbuvir, daclatasvir, or ledipasvir, HCV eradication is possible in the vast majority of HCV infected individuals by DAA combinations with or without pegylated interferon-α. This review summarized these exciting developments with a focus on current recommendations for the treatment of chronic hepatitis C.

  16. An evolutionary screen highlights canonical and noncanonical candidate antiviral genes within the primate TRIM gene family.

    PubMed

    Malfavon-Borja, Ray; Sawyer, Sara L; Wu, Lily I; Emerman, Michael; Malik, Harmit S

    2013-01-01

    Recurrent viral pressure has acted on host-encoded antiviral genes during primate and mammalian evolution. This selective pressure has resulted in dramatic episodes of adaptation in host antiviral genes, often detected via positive selection. These evolutionary signatures of adaptation have the potential to highlight previously unrecognized antiviral genes (also called restriction factors). Although the TRIM multigene family is recognized for encoding several bona fide restriction factors (e.g., TRIM5alpha), most members of this expansive gene family remain uncharacterized. Here, we investigated the TRIM multigene family for signatures of positive selection to identify novel candidate antiviral genes. Our analysis reveals previously undocumented signatures of positive selection in 17 TRIM genes, 10 of which represent novel candidate restriction factors. These include the unusual TRIM52 gene, which has evolved under strong positive selection despite its encoded protein lacking a putative viral recognition (B30.2) domain. We show that TRIM52 arose via gene duplication from the TRIM41 gene. Both TRIM52 and TRIM41 have dramatically expanded RING domains compared with the rest of the TRIM multigene family, yet this domain has evolved under positive selection only in primate TRIM52, suggesting that it represents a novel host-virus interaction interface. Our evolutionary-based screen not only documents positive selection in known TRIM restriction factors but also highlights candidate novel restriction factors, providing insight into the interfaces of host-pathogen interactions mediated by the TRIM multigene family.

  17. Fast-forward generation of effective artificial small RNAs for enhanced antiviral defense in plants.

    PubMed

    Carbonell, Alberto; Carrington, James C; Daròs, José-Antonio

    Artificial small RNAs (sRNAs) are short ≈21-nt non-coding RNAs engineered to inactivate sequence complementary RNAs. In plants, they have been extensively used to silence cellular transcripts in gene function analyses and to target invading RNA viruses to induce resistance. Current artificial sRNA-based antiviral resistance in plants is mainly limited to a single virus, and is jeopardized by the emergence of mutations in the artificial sRNA target site or by the presence of co-infecting viruses. Hence, there is a need to further develop the artificial sRNA approach to generate more broad and durable antiviral resistance in plants. A recently developed toolbox allows for the time and cost-effective large-scale production of artificial sRNA constructs in plants. The toolbox includes the P-SAMS web tool for the automated design of artificial sRNAs, and a new generation of artificial microRNA and synthetic trans-acting small interfering RNA (syn-tasiRNA) vectors for direct cloning and high expression of artificial sRNAs. Here we describe how the simplicity and high-throughput capability of these new technologies should accelerate the study of artificial sRNA-based antiviral resistance in plants. In particular, we discuss the potential of the syn-tasiRNA approach as a promising strategy for developing more effective, durable and broad antiviral resistance in plants.

  18. Epidemiological consequences of household-based antiviral prophylaxis for pandemic influenza

    PubMed Central

    Black, Andrew J.; House, Thomas; Keeling, M. J.; Ross, J. V.

    2013-01-01

    Antiviral treatment offers a fast acting alternative to vaccination; as such it is viewed as a first-line of defence against pandemic influenza in protecting families and households once infection has been detected. In clinical trials, antiviral treatments have been shown to be efficacious in preventing infection, limiting disease and reducing transmission, yet their impact at containing the 2009 influenza A(H1N1)pdm outbreak was limited. To understand this seeming discrepancy, we develop a general and computationally efficient model for studying household-based interventions. This allows us to account for uncertainty in quantities relevant to the 2009 pandemic in a principled way, accounting for the heterogeneity and variability in each epidemiological process modelled. We find that the population-level effects of delayed antiviral treatment and prophylaxis mean that their limited overall impact is quantitatively consistent (at current levels of precision) with their reported clinical efficacy under ideal conditions. Hence, effective control of pandemic influenza with antivirals is critically dependent on early detection and delivery ideally within 24 h. PMID:23389899

  19. 1,3,4-oxadiazole: a privileged structure in antiviral agents.

    PubMed

    Li, Z; Zhan, P; Liu, X

    2011-11-01

    1,3,4-oxadiazole, a privileged structure, endows its derivatives with broad and potent biological functions, especially in antiviral activities, including anti-HIV, anti-HCV, anti-HBV, anti-HSV activities, etc. Molecular modeling and pharmacokinetic studies have demonstrated that the introduction of 1,3,4-oxadiazole ring to the inhibitors can change their polarity, flexibility as well as metabolic stability, and 1,3,4-oxadiazole scaffold can also act as acceptors of hydrogen bonds formation, which make it possible to be used as a isosteric substituent for amide or ester groups. This review focuses on the recent advances in the synthesis of 1,3,4-oxadiazole ring and mainly the discovery, biological activities investigations and structural modifications of several distinct classes of 1,3,4-oxadiazoles as potent antiviral agents. In addition, the binding models of some representative 1,3,4-oxadiazoles were also discussed, which provide rational explanation for their interesting antiviral activities, and also pave the way for further optimization of 1,3,4- oxadiazole based antiviral agents.

  20. Ultrasensitive HCV RNA Quantification in Antiviral Triple Therapy: New Insight on Viral Clearance Dynamics and Treatment Outcome Predictors

    PubMed Central

    Garbuglia, Anna Rosa; Visco-Comandini, Ubaldo; Lionetti, Raffaella; Lapa, Daniele; Castiglione, Filippo; D’Offizi, Gianpiero; Taibi, Chiara; Montalbano, Marzia; Capobianchi, Maria Rosaria; Paci, Paola

    2016-01-01

    Objectives Identifying the predictive factors of Sustained Virological Response (SVR) represents an important challenge in new interferon-based DAA therapies. Here, we analyzed the kinetics of antiviral response associated with a triple drug regimen, and the association between negative residual viral load at different time points during treatment. Methods Twenty-three HCV genotype 1 (GT 1a n = 11; GT1b n = 12) infected patients were included in the study. Linear Discriminant Analysis (LDA) was used to establish possible association between HCV RNA values at days 1 and 4 from start of therapy and SVR. Principal component analysis (PCA) was applied to analyze the correlation between HCV RNA slope and SVR. A ultrasensitive (US) method was established to measure the residual HCV viral load in those samples which resulted “detected <12IU/ml” or undetectable with ABBOTT standard assay, and was retrospectively used on samples collected at different time points to establish its predictive power for SVR. Results According to LDA, there was no association between SVR and viral kinetics neither at time points earlier than 1 week (days 1 and 4) after therapy initiation nor later. The slopes were not relevant for classifying patients as SVR or no-SVR. No significant differences were observed in the median HCV RNA values at T0 among SVR and no-SVR patients. HCV RNA values with US protocol (LOD 1.2 IU/ml) after 1 month of therapy were considered; the area under the ROC curve was 0.70. Overall, PPV and NPV of undetectable HCV RNA with the US method for SVR was 100% and 46.7%, respectively; sensitivity and specificity were 38.4% and 100% respectively. Conclusion HCV RNA “not detected” by the US method after 1 month of treatment is predictive of SVR in first generation Protease inhibitor (PI)-based triple therapy. The US method could have clinical utility for advanced monitoring of virological response in new interferon based DAA combination regimens. PMID:27560794

  1. Antiviral potential of lactic acid bacteria and their bacteriocins.

    PubMed

    Al Kassaa, I; Hober, D; Hamze, M; Chihib, N E; Drider, D

    2014-12-01

    Emerging resistance to antiviral agents is a growing public health concern worldwide as it was reported for respiratory, sexually transmitted and enteric viruses. Therefore, there is a growing demand for new, unconventional antiviral agents which may serve as an alternative to the currently used drugs. Meanwhile, published literature continues shedding the light on the potency of lactic acid bacteria (LAB) and their bacteriocins as antiviral agents. Health-promoting LAB probiotics may exert their antiviral activity by (1) direct probiotic-virus interaction; (2) production of antiviral inhibitory metabolites; and/or (3) via stimulation of the immune system. The aim of this review was to highlight the antiviral activity of LAB and substances they produce with antiviral activity.

  2. Antiviral herbs--present and future.

    PubMed

    Huang, Jun; Su, Dan; Feng, Yulin; Liu, Kuangyi; Song, Yonggui

    2014-01-01

    Viral disease is a calamity which absolutely can not be ignored for human health. The emergence of drug resistance and spread of new virus will be the new challenge against viral disease. To find and develop new antivirus agents with properties of safety, significant effect and low toxicity is the pressing question facing humans today. Because of its advantages, including rich resources, low price, less adverse effect, Traditional Chinese medicine (TCM) have become the research focus in antiviral treatment. In recent years, there are numerous articles about the studies from separation of active ingredients to the antiviral mechanism. In this paper, the progress in experimental study was illustrated on the basis of active ingredients, species of virus, mechanism, clinical application. Obviously, TCM have obvious advantages in the treatment of virus infectious disease and has a broad prospect of application.

  3. Glycodendritic structures: promising new antiviral drugs.

    PubMed

    Rojo, Javier; Delgado, Rafael

    2004-09-01

    DC-SIGN, a C-type lectin expressed by dendritic cells, is able to recognize high mannosylated glycoproteins at the surface of a broad range of pathogens including viruses, bacteria, fungi and parasites. For at least some of these agents this interaction appears to be an important part of the infection process. Therefore, this lectin might be considered in the design of new antiviral drugs. In this manner, multivalent carbohydrate systems based on dendrimers and dendritic polymers are promising candidates as antiviral drugs. Boltorn hyperbranched dendritic polymers functionalized with mannose have been used to inhibit DC-SIGN-mediated infection in an Ebola-pseudotyped viral model. Their physiological solubility, lack of toxicity and especially their low price suggest the application of these glycodendritic polymers for possible formulation as microbicides.

  4. Antiviral and antiretroviral use in pregnancy.

    PubMed

    Money, Deborah M

    2003-12-01

    The history of antiviral and antiretroviral therapy is recent compared with many other medical therapies, including traditional antibiotics in pregnancy. There are few long-term data on which to base decisions of management in pregnancy. Accessing up-to-date information is critical to optimizing the safety of care for mothers and their infants. Exposure to medications in pregnancy can be toxic to a fetus in a gestational age-dependent manner. Determination of safe medications for pregnancy must take into consideration the need for certain medications and the possibility of inadvertent exposure in early pregnancy because of unplanned pregnancies. This article reviews the most commonly used antiviral and antiretroviral agents and places emphasis on the issues regarding use in pregnancy.

  5. Clinical Implications of Antiviral Resistance in Influenza

    PubMed Central

    Li, Timothy C. M.; Chan, Martin C. W.; Lee, Nelson

    2015-01-01

    Influenza is a major cause of severe respiratory infections leading to excessive hospitalizations and deaths globally; annual epidemics, pandemics, and sporadic/endemic avian virus infections occur as a result of rapid, continuous evolution of influenza viruses. Emergence of antiviral resistance is of great clinical and public health concern. Currently available antiviral treatments include four neuraminidase inhibitors (oseltamivir, zanamivir, peramivir, laninamivir), M2-inibitors (amantadine, rimantadine), and a polymerase inhibitor (favipiravir). In this review, we focus on resistance issues related to the use of neuraminidase inhibitors (NAIs). Data on primary resistance, as well as secondary resistance related to NAI exposure will be presented. Their clinical implications, detection, and novel therapeutic options undergoing clinical trials are discussed. PMID:26389935

  6. Clinical Implications of Antiviral Resistance in Influenza.

    PubMed

    Li, Timothy C M; Chan, Martin C W; Lee, Nelson

    2015-09-14

    Influenza is a major cause of severe respiratory infections leading to excessive hospitalizations and deaths globally; annual epidemics, pandemics, and sporadic/endemic avian virus infections occur as a result of rapid, continuous evolution of influenza viruses. Emergence of antiviral resistance is of great clinical and public health concern. Currently available antiviral treatments include four neuraminidase inhibitors (oseltamivir, zanamivir, peramivir, laninamivir), M2-inibitors (amantadine, rimantadine), and a polymerase inhibitor (favipiravir). In this review, we focus on resistance issues related to the use of neuraminidase inhibitors (NAIs). Data on primary resistance, as well as secondary resistance related to NAI exposure will be presented. Their clinical implications, detection, and novel therapeutic options undergoing clinical trials are discussed.

  7. Polyomavirus T Antigens Activate an Antiviral State

    PubMed Central

    Giacobbi, Nicholas S.; Gupta, Tushar; Coxon, Andrew; Pipas, James M.

    2014-01-01

    Ectopic expression of Simian Virus 40 (SV40) large T antigen (LT) in mouse embryonic fibroblasts (MEFs) increased levels of mRNAs encoding interferon stimulated genes (ISGs). The mechanism by which T antigen increases levels of ISGs in MEFs remains unclear. We present evidence that expression of T antigen from SV40, Human Polyomaviruses BK (BKV) or JC (JCV) upregulate production of ISGs in MEFs, and subsequently result in an antiviral state, as determined by inhibition of VSV or EMCV growth. The first 136 amino acids of LT are sufficient for these activities. Furthermore, increased ISG expression and induction of the antiviral state requires STAT1. Finally, the RB binding motif of LT is necessary for activation of STAT1. We conclude that the induction of the STAT1 mediated innate immune response in MEFs is a common feature shared by SV40, BKV and JCV. PMID:25589241

  8. An antiviral furanoquinone from Paulownia tomentosa Steud.

    PubMed

    Kang, K H; Huh, H; Kim, B K; Lee, C K

    1999-11-01

    A methanol extract of the stem bark of Paulownia tomentosa showed antiviral activity against poliovirus types 1 and 3. Sequential liquid-liquid extraction with n-hexane, chloroform and water, and a silicagel column chromatography resulted in the purification of a compound. The compound was identified as methyl-5-hydroxy-dinaphthol[1,2-2',3']furan-7,12-dione-6-carbox yla te on the basis of spectroscopic data. The component caused a significant reduction of viral cytopathic effect when it was subjected to a standard antiviral assay by using HeLa cells. The EC(50) of the compound against poliovirus type 1 strain Brunhilde, and type 3 strain Leon were 0.3 microg/mL and 0.6 microg/mL, respectively.

  9. Antiviral Lead Compounds from Marine Sponges

    PubMed Central

    Sagar, Sunil; Kaur, Mandeep; Minneman, Kenneth P.

    2010-01-01

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. PMID:21116410

  10. Antiviral activities of atractylon from Atractylodis Rhizoma

    PubMed Central

    Cheng, Yang; Mai, Jing-Yin; Hou, Tian-Lu; Ping, Jian; Chen, Jian-Jie

    2016-01-01

    Atractylodis Rhizoma is a traditional medicinal herb, which has antibacterial, antiviral, anti-inflammatory and anti-allergic, anticancer, gastroprotective and neuroprotective activities. It is widely used for treating fever, cold, phlegm, edema and arthralgia syndrome in South-East Asian nations. In this study, 6 chemical compositions of Atractylodis Rhizoma were characterized by spectral analysis and their antiviral activities were evaluated in vitro and in vivo. Among them, atractylon showed most significant antiviral activities. Atractylon treatment at doses of 10–40 mg/kg for 5 days attenuated influenza A virus (IAV)-induced pulmonary injury and decreased the serum levels of interleukin (IL)-6, tumor necrosis factor-α and IL-1β, but increased interferon-β (IFN-β) levels. Atractylon treatment upregulated the expression of Toll-like receptor 7 (TLR7), MyD88, tumor necrosis factor receptor-associated factor 6 and IFN-β mRNA but downregulated nuclear factor-κB p65 protein expression in the lung tissues of IAV-infected mice. These results demonstrated that atractylon significantly alleviated IAV-induced lung injury via regulating the TLR7 signaling pathway, and may warrant further evaluation as a possible agent for IAV treatment. PMID:27600871

  11. Contribution of Type III Interferons to Antiviral Immunity; Location, Location, Location.

    PubMed

    Kotenko, Sergei V; Durbin, Joan E

    2017-03-13

    Type I interferons (IFN-α/β) and the more recently identified type III IFNs (IFN-λ) function as the first line of defense against virus infection, and regulate the development of both innate and adaptive immune responses. Type III IFNs were originally identified as a novel ligand-receptor system acting in parallel with type I IFNs, but subsequent studies have provided increasing evidence for distinct roles for each IFN family. In addition to their compartmentalized antiviral actions, these two systems appear to have multiple levels of cross-regulation, and act coordinately to achieve effective anti-microbial protection with minimal collateral damage to the host.

  12. Drug-induced lung injury associated with combination therapy of daclatasvir and asunaprevir: The first case report.

    PubMed

    Kamada, Takahiro; Furuta, Kenjiro; Tomioka, Hiromi

    2016-05-01

    Combination therapy with direct acting antiviral agents (DAAs) without interferon (IFN) has emerged as a treatment for chronic hepatitis C because of its high overall sustained virologic response rates and favorable side effect profile as compared to that with interferon. We report the first case of drug-induced lung injury (DLI) associated with IFN-free therapy with the DAAs, daclatasvir (NS5A inhibitor) and asunaprevir (NS3/4A protease inhibitor). Although this combination therapy of DAAs has been considered to have fewer side effects than IFN, more attention should be paid to DLI as an important side effect.

  13. A case for developing antiviral drugs against polio.

    PubMed

    Collett, Marc S; Neyts, Johan; Modlin, John F

    2008-09-01

    Polio eradication is within sight. In bringing the world close to this ultimate goal, the Global Polio Eradication Initiative (GPEI) has relied exclusively on the live, attenuated oral poliovirus vaccine (OPV). However, as eradication nears, continued OPV use becomes less tenable due to the incidence of vaccine associated paralytic poliomyelitis (VAPP) in vaccine recipients and disease caused by circulating vaccine-derived polioviruses (cVDPVs) in contacts. Once wild poliovirus transmission has been interrupted globally, OPV use will stop. This will leave the inactivated poliovirus vaccine (IPV) as the only weapon to defend a polio-free world. Outbreaks caused by cVDPVs are expected post-OPV cessation, and accidental or deliberate releases of virus could also occur. There are serious doubts regarding the ability of IPV alone to control outbreaks. Here, we argue that antiviral drugs against poliovirus be added to the arsenal. Anti-poliovirus drugs could be used to treat the infected and protect the exposed, acting rapidly on their own to contain an outbreak and used as a complement to IPV. While there are no polio antiviral drugs today, the technological feasibility of developing such drugs and their probability of clinical success have been established by over three decades of drug development targeting the related rhinoviruses and non-polio enteroviruses (NPEVs). Because of this history, there are known compounds with anti-poliovirus activity in vitro that represent excellent starting points for polio drug development. Stakeholders must come to understand the potential public health benefits of polio drugs, the feasibility of their development, and the relatively modest costs involved. Given the timelines for eradication and those for drug development, the time for action is now.

  14. 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

  15. Cutaneous manifestations of hepatitis C in the era of new antiviral agents

    PubMed Central

    Garcovich, Simone; Garcovich, Matteo; Capizzi, Rodolfo; Gasbarrini, Antonio; Zocco, Maria Assunta

    2015-01-01

    The association of chronic hepatitis C virus (HCV) infection with a wide spectrum of cutaneous manifestations has been widely reported in the literature, with varying strength of epidemiological association. Skin diseases which are certainly related with chronic HCV infection due to a strong epidemiological and pathogenetic association are mixed cryoglobulinemia, lichen planus and porphyria cutanea tarda. Chronic pruritus and necrolytic acral erythema are conditions that may share a possible association with HCV infection, while several immune-mediated inflammatory skin conditions, such as psoriasis, chronic urticaria and vitiligo, have been only anecdotally reported in the setting of chronic HCV infection. Traditional interferon-based treatment regimens for HCV infection are associated with substantial toxicity and a high-risk of immune-related adverse events, while the advent of new direct-acting antivirals with sustained virological response and improved tolerability will open the door for all-oral, interferon-free regimens. In the new era of these direct acting antivirals there will be hopefully a renewed interest in extra-hepatic manifestations of HCV infection. The aim of the present paper is to review the main cutaneous HCV-related disorders - mixed cryoglobulinemia, lichen planus, porphyria cutanea tarda and chronic pruritus - and to discuss the potential impact of new antiviral treatments on the course of these extra-hepatic manifestations of chronic HCV infection. PMID:26644817

  16. 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.

  17. 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

  18. Letermovir and inhibitors of the terminase complex: a promising new class of investigational antiviral drugs against human cytomegalovirus

    PubMed Central

    Melendez, Dante P; Razonable, Raymund R

    2015-01-01

    Infection with cytomegalovirus is prevalent in immunosuppressed patients. In solid organ transplant and hematopoietic stem cell transplant recipients, cytomegalovirus infection is associated with high morbidity and preventable mortality. Prevention and treatment of cytomegalovirus with currently approved antiviral drugs is often associated with side effects that sometimes preclude their use. Moreover, cytomegalovirus has developed mutations that confer resistance to standard antiviral drugs. During the last decade, there have been calls to develop novel antiviral drugs that could provide better options for prevention and treatment of cytomegalovirus. Letermovir (AIC246) is a highly specific antiviral drug that is currently undergoing clinical development for the management of cytomegalovirus infection. It acts by inhibiting the viral terminase complex. Letermovir is highly potent in vitro and in vivo against cytomegalovirus. Because of a distinct mechanism of action, it does not exhibit cross-resistance with other antiviral drugs. It is predicted to be active against strains that are resistant to ganciclovir, foscarnet, and cidofovir. To date, early-phase clinical trials suggest a very low incidence of adverse effects. Herein, we present a comprehensive review on letermovir, from its postulated novel mechanism of action to the results of most recent clinical studies. PMID:26345608

  19. Antiviral therapy for hepatitis C: Has anything changed for pregnant/lactating women?

    PubMed

    Spera, Anna Maria; Eldin, Tarek Kamal; Tosone, Grazia; Orlando, Raffaele

    2016-04-28

    Hepatitis C virus (HCV) affects about 3% of the world's population, with the highest prevalence in individuals under 40. The prevalence in pregnant women varies with geographical distribution (highest in developing countries). Prevalence also increases in sub-populations of women at high risk for blood-transmitted infections. HCV infection in pregnancy represents a non-negligible problem. However, most of the past antiviral regimens cannot be routinely offered to pregnant or breastfeeding women because of their side effects. We briefly reviewed the issue of treatment of HCV infection in pregnant/breastfeeding women focusing on the effects of the new direct-acting antivirals on fertility, pregnancy and lactation in animal studies and on the potential risk for humans based on the pharmacokinetic properties of each drug. Currently, all new therapy regimens are contraindicated in this setting because of lack of sufficient safety information and adequate measures of contraception are still routinely recommended for female patients of childbearing potential.

  20. Bugs Are Not to Be Silenced: Small RNA Pathways and Antiviral Responses in Insects.

    PubMed

    Mongelli, Vanesa; Saleh, Maria-Carla

    2016-09-29

    Like every other organism on Earth, insects are infected with viruses, and they rely on RNA interference (RNAi) mechanisms to circumvent viral infections. A remarkable characteristic of RNAi is that it is both broadly acting, because it is triggered by double-stranded RNA molecules derived from virtually any virus, and extremely specific, because it targets only the particular viral sequence that initiated the process. Reviews covering the different facets of the RNAi antiviral immune response in insects have been published elsewhere. In this review, we build a framework to guide future investigation. We focus on the remaining questions and avenues of research that need to be addressed to move the field forward, including issues such as the activity of viral suppressors of RNAi, comparative genomics, the development of detailed maps of the subcellular localization of viral replication complexes with the RNAi machinery, and the regulation of the antiviral RNAi response.

  1. Determining Mechanism of Action of Antivirals for Respiratory Illness

    NASA Astrophysics Data System (ADS)

    Rodriguez, Irma; Dobrovolny, Hana

    2015-03-01

    Viral infections in the respiratory tract are common in humans and can cause serious illness and death. Drug treatment is the principal line of protection against many of these illnesses and many compounds are tested as antivirals. Often the efficacy of these antivirals are determined before a mechanism of action is understood. We use mathematical models to represent the evolution of these diseases and establish which experiments can help determine the mechanism of action of antivirals.

  2. Hydrogen bonds and antiviral activity of benzaldehyde derivatives

    NASA Astrophysics Data System (ADS)

    Tolstorozhev, G. B.; Skornyakov, I. V.; Belkov, M. V.; Shadyro, O. I.; Brinkevich, S. D.; Samovich, S. N.

    2012-09-01

    We have obtained the Fourier transform IR spectra of solutions of benzaldehyde derivatives having different antiviral activities against a herpes virus. We observe a correlation between the presence of hydrogen bonds in the benzaldehyde molecules and the appearance of antiviral properties in the compounds. For compounds having antiviral activity, we have obtained spectral data suggesting the existence of hydrogen bonds of the type C=OṡṡṡH-O and O-HṡṡṡO in the molecules. When the hydrogen atom in the hydroxyl groups are replaced by a methyl group, no intramolecular hydrogen bonds are formed and the compounds lose their antiviral activity.

  3. 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.

  4. Antiviral treatment of Argentine hemorrhagic fever.

    PubMed

    Enria, D A; Maiztegui, J I

    1994-01-01

    Argentine hemorrhagic fever is a systemic viral disease caused by Junin virus, with a mortality of 15-30% in untreated individuals. Current specific therapy is highly effective in reducing mortality, and consists of the early administration of immune plasma in defined doses of specific neutralizing antibodies per kg of body weight. However, several reasons suggest the need to investigate alternative therapies. Ribavirin, a broad spectrum antiviral agent, is effective in the treatment of other viral hemorrhagic fevers, and the studies done with Junin virus infections to date indicate that this drug may also have a beneficial effect in Argentine hemorrhagic fever.

  5. Inflammatory monocytes hinder antiviral B cell responses

    PubMed Central

    Sammicheli, Stefano; Kuka, Mirela; Di Lucia, Pietro; de Oya, Nereida Jimenez; De Giovanni, Marco; Fioravanti, Jessica; Cristofani, Claudia; Maganuco, Carmela G.; Fallet, Benedict; Ganzer, Lucia; Sironi, Laura; Mainetti, Marta; Ostuni, Renato; Larimore, Kevin; Greenberg, Philip D.; de la Torre, Juan Carlos; Guidotti, Luca G.; Iannacone, Matteo

    2016-01-01

    Antibodies are critical for protection against viral infections. However, several viruses, such as lymphocytic choriomeningitis virus (LCMV), avoid the induction of early protective antibody responses by poorly understood mechanisms. Here we analyzed the spatiotemporal dynamics of B cell activation to show that, upon subcutaneous infection, LCMV-specific B cells readily relocate to the interfollicular and T cell areas of the draining lymph node where they extensively interact with CD11b+Ly6Chi inflammatory monocytes. These myeloid cells were recruited to lymph nodes draining LCMV infection sites in a type I interferon-, CCR2-dependent fashion and they suppressed antiviral B cell responses by virtue of their ability to produce nitric oxide. Depletion of inflammatory monocytes, inhibition of their lymph node recruitment or impairment of their nitric oxide-producing ability enhanced LCMV-specific B cell survival and led to robust neutralizing antibody production. In conclusion, our results identify inflammatory monocytes as critical gatekeepers that prevent antiviral B cell responses and suggest that certain viruses take advantage of these cells to prolong their persistence within the host. PMID:27868108

  6. Antiviral Defenses in Plants through Genome Editing

    PubMed Central

    Romay, Gustavo; Bragard, Claude

    2017-01-01

    Plant–virus interactions based-studies have contributed to increase our understanding on plant resistance mechanisms, providing new tools for crop improvement. In the last two decades, RNA interference, a post-transcriptional gene silencing approach, has been used to induce antiviral defenses in plants with the help of genetic engineering technologies. More recently, the new genome editing systems (GES) are revolutionizing the scope of tools available to confer virus resistance in plants. The most explored GES are zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats/Cas9 endonuclease. GES are engineered to target and introduce mutations, which can be deleterious, via double-strand breaks at specific DNA sequences by the error-prone non-homologous recombination end-joining pathway. Although GES have been engineered to target DNA, recent discoveries of GES targeting ssRNA molecules, including virus genomes, pave the way for further studies programming plant defense against RNA viruses. Most of plant virus species have an RNA genome and at least 784 species have positive ssRNA. Here, we provide a summary of the latest progress in plant antiviral defenses mediated by GES. In addition, we also discuss briefly the GES perspectives in light of the rebooted debate on genetic modified organisms (GMOs) and the current regulatory frame for agricultural products involving the use of such engineering technologies. PMID:28167937

  7. Avian Interferons and Their Antiviral Effectors.

    PubMed

    Santhakumar, Diwakar; Rubbenstroth, Dennis; Martinez-Sobrido, Luis; Munir, Muhammad

    2017-01-01

    Interferon (IFN) responses, mediated by a myriad of IFN-stimulated genes (ISGs), are the most profound innate immune responses against viruses. Cumulatively, these IFN effectors establish a multilayered antiviral state to safeguard the host against invading viral pathogens. Considerable genetic and functional characterizations of mammalian IFNs and their effectors have been made, and our understanding on the avian IFNs has started to expand. Similar to mammalian counterparts, three types of IFNs have been genetically characterized in most avian species with available annotated genomes. Intriguingly, chickens are capable of mounting potent innate immune responses upon various stimuli in the absence of essential components of IFN pathways including retinoic acid-inducible gene I, IFN regulatory factor 3 (IRF3), and possibility IRF9. Understanding these unique properties of the chicken IFN system would propose valuable targets for the development of potential therapeutics for a broader range of viruses of both veterinary and zoonotic importance. This review outlines recent developments in the roles of avian IFNs and ISGs against viruses and highlights important areas of research toward our understanding of the antiviral functions of IFN effectors against viral infections in birds.

  8. Cell senescence is an antiviral defense mechanism

    PubMed Central

    Baz-Martínez, Maite; Da Silva-Álvarez, Sabela; Rodríguez, Estefanía; Guerra, Jorge; El Motiam, Ahmed; Vidal, Anxo; García-Caballero, Tomás; González-Barcia, Miguel; Sánchez, Laura; Muñoz-Fontela, César; Collado, Manuel; Rivas, Carmen

    2016-01-01

    Cellular senescence is often considered a protection mechanism triggered by conditions that impose cellular stress. Continuous proliferation, DNA damaging agents or activated oncogenes are well-known activators of cell senescence. Apart from a characteristic stable cell cycle arrest, this response also involves a proinflammatory phenotype known as senescence-associated secretory phenotype (SASP). This, together with the widely known interference with senescence pathways by some oncoviruses, had led to the hypothesis that senescence may also be part of the host cell response to fight virus. Here, we evaluate this hypothesis using vesicular stomatitis virus (VSV) as a model. Our results show that VSV replication is significantly impaired in both primary and tumor senescent cells in comparison with non-senescent cells, and independently of the stimulus used to trigger senescence. Importantly, we also demonstrate a protective effect of senescence against VSV in vivo. Finally, our results identify the SASP as the major contributor to the antiviral defense exerted by cell senescence in vitro, and points to a role activating and recruiting the immune system to clear out the infection. Thus, our study indicates that cell senescence has also a role as a natural antiviral defense mechanism. PMID:27849057

  9. Avian Interferons and Their Antiviral Effectors

    PubMed Central

    Santhakumar, Diwakar; Rubbenstroth, Dennis; Martinez-Sobrido, Luis; Munir, Muhammad

    2017-01-01

    Interferon (IFN) responses, mediated by a myriad of IFN-stimulated genes (ISGs), are the most profound innate immune responses against viruses. Cumulatively, these IFN effectors establish a multilayered antiviral state to safeguard the host against invading viral pathogens. Considerable genetic and functional characterizations of mammalian IFNs and their effectors have been made, and our understanding on the avian IFNs has started to expand. Similar to mammalian counterparts, three types of IFNs have been genetically characterized in most avian species with available annotated genomes. Intriguingly, chickens are capable of mounting potent innate immune responses upon various stimuli in the absence of essential components of IFN pathways including retinoic acid-inducible gene I, IFN regulatory factor 3 (IRF3), and possibility IRF9. Understanding these unique properties of the chicken IFN system would propose valuable targets for the development of potential therapeutics for a broader range of viruses of both veterinary and zoonotic importance. This review outlines recent developments in the roles of avian IFNs and ISGs against viruses and highlights important areas of research toward our understanding of the antiviral functions of IFN effectors against viral infections in birds. PMID:28197148

  10. Bell's Palsy: Treatment with Steroids and Antiviral Drugs

    MedlinePlus

    ... Evidence-based Guideline for PATIENTS and their FAMILIES BELL’S PALSY: TREATMENT WITH STEROIDS AND ANTIVIRAL DRUGS This information ... role of steroids and antiviral drugs for treating Bell’s palsy. Neurologists from the AAN are doctors who identify ...

  11. Potential applications for antiviral therapy and prophylaxis in bovine medicine.

    PubMed

    Newcomer, Benjamin W; Walz, Paul H; Givens, M Daniel

    2014-06-01

    Viral disease is one of the major causes of financial loss and animal suffering in today's cattle industry. Increases in global commerce and average herd size, urbanization, vertical integration within the industry and alterations in global climate patterns have allowed the spread of pathogenic viruses, or the introduction of new viral species, into regions previously free of such pathogens, creating the potential for widespread morbidity and mortality in naïve cattle populations. Despite this, no antiviral products are currently commercially licensed for use in bovine medicine, although significant progress has been made in the development of antivirals for use against bovine viral diarrhea virus (BVDV), foot and mouth disease virus (FMDV) and bovine herpesvirus (BHV). BVDV is extensively studied as a model virus for human antiviral studies. Consequently, many compounds with efficacy have been identified and a few have been successfully used to prevent infection in vivo although commercial development is still lacking. FMDV is also the subject of extensive antiviral testing due to the importance of outbreak containment for maintenance of export markets. Thirdly, BHV presents an attractive target for antiviral development due to its worldwide presence. Antiviral studies for other bovine viral pathogens are largely limited to preliminary studies. This review summarizes the current state of knowledge of antiviral compounds against several key bovine pathogens and the potential for commercial antiviral applications in the prevention and control of several selected bovine diseases.

  12. Protein kinase C and the antiviral effect of human interferon.

    PubMed

    Cernescu, C; Constantinescu, S N; Baltă, F; Popescu, L M; Cajal, N

    1989-01-01

    Protein kinase C (PKC) inhibitors: Hidaka's compounds H-7 (10 microM) and H-8 (20 microM), palmitoyl-carnitine (10 microM) and phloretin (50 microM), did not modify the antiviral effect of human natural or recombinant interferon alpha and of natural interferon beta. The tumor promoter 12-o-tetradecanoyl-phorbol-13-acetate (TPA) (200 nM), known as activator of PKC induced an antiviral state when tested on human embryo fibroblasts challenged with the vesicular stomatitis virus. The battery of PKC inhibitors used inhibited the antiviral effect induced by TPA. Palmitoyl-carnitine (10 microM) exerted a toxic effect that was reversed by interferon treatment (2,000 IU/ml interferon alpha). These results suggest that PKC, possibly activated by interferon-receptor interaction, is not essential for inducing the antiviral effect of interferon, but, probably, mediates the antiviral effect of TPA.

  13. Antiviral activity and increased host defense against influenza infection elicited by the human cathelicidin LL-37.

    PubMed

    Barlow, Peter G; Svoboda, Pavel; Mackellar, Annie; Nash, Anthony A; York, Ian A; Pohl, Jan; Davidson, Donald J; Donis, Ruben O

    2011-01-01

    The extensive world-wide morbidity and mortality caused by influenza A viruses highlights the need for new insights into the host immune response and novel treatment approaches. Cationic Host Defense Peptides (CHDP, also known as antimicrobial peptides), which include cathelicidins and defensins, are key components of the innate immune system that are upregulated during infection and inflammation. Cathelicidins have immunomodulatory and anti-viral effects, but their impact on influenza virus infection has not been previously assessed. We therefore evaluated the effect of cathelicidin peptides on disease caused by influenza A virus in mice. The human cathelicidin, LL-37, and the murine cathelicidin, mCRAMP, demonstrated significant anti-viral activity in vivo, reducing disease severity and viral replication in infected mice to a similar extent as the well-characterized influenza virus-specific antiviral drug zanamivir. In vitro and in vivo experiments suggested that the peptides may act directly on the influenza virion rather than via receptor-based mechanisms. Influenza virus-infected mice treated with LL-37 had lower concentrations of pro-inflammatory cytokines in the lung than did infected animals that had not been treated with cathelicidin peptides. These data suggest that treatment of influenza-infected individuals with cathelicidin-derived therapeutics, or modulation of endogenous cathelicidin production may provide significant protection against disease.

  14. Hepatitis C virus molecular evolution: transmission, disease progression and antiviral therapy.

    PubMed

    Preciado, Maria Victoria; Valva, Pamela; Escobar-Gutierrez, Alejandro; Rahal, Paula; Ruiz-Tovar, Karina; Yamasaki, Lilian; Vazquez-Chacon, Carlos; Martinez-Guarneros, Armando; Carpio-Pedroza, Juan Carlos; Fonseca-Coronado, Salvador; Cruz-Rivera, Mayra

    2014-11-21

    Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era.

  15. New Prospects for the Treatment and Prevention of Hepatitis C in Children

    PubMed Central

    Ohmer, Samantha; Honegger, Jonathan

    2016-01-01

    Purpose of review Combined pegylated interferon-α and ribavirin remain the standard therapy for pediatric hepatitis C virus (HCV) infection in 2016, but direct acting antivirals (DAAs) with greatly improved efficacy and safety are now approved for adults. Here we review the major classes of DAAs and their anticipated use for treatment and potentially prevention of HCV in children. Recent findings Currently approved DAAs target the viral protease, polymerase, and NS5A, a protein involved in viral replication and assembly. In combination, they have lifted sustained virologic response rates to over 90% for multiple HCV genotypes, and the rich DAA pipeline promises further improvements. Clinical trials of interferon-free DAA regimens have been initiated for children ages 3–17 years. The first efficacy trial of a preventative HCV vaccine for adults is also underway. While awaiting a vaccine, there is hope that increased DAA uptake may prevent pediatric HCV infections by shrinking the pool of infectious persons. Summary Interferon-free DAA regimens have revolutionized therapy for HCV-infected adults and pending results of pediatric trials will likely do the same for HCV-infected children. If widely deployed, particularly amongst individuals likely to transmit HCV, DAA therapies may also help reduce new vertically- and horizontally-acquired pediatric infections. PMID:26709684

  16. Contribution of Toll-like receptors to the control of hepatitis B virus infection by initiating antiviral innate responses and promoting specific adaptive immune responses

    PubMed Central

    Ma, Zhiyong; Zhang, Ejuan; Yang, Dongliang; Lu, Mengji

    2015-01-01

    It is well accepted that adaptive immunity plays a key role in the control of hepatitis B virus (HBV) infection. In contrast, the contribution of innate immunity has only received attention in recent years. Toll-like receptors (TLRs) sense pathogen-associated molecule patterns and activate antiviral mechanisms, including intracellular antiviral pathways and the production of antiviral effector interferons (IFNs) and pro-inflammatory cytokines. Experimental results from in vitro and in vivo models have demonstrated that TLRs mediate the activation of cellular signaling pathways and the production of antiviral cytokines, resulting in a suppression of HBV replication. However, HBV infection is associated with downregulation of TLR expression on host cells and blockade of the activation of downstream signaling pathways. In primary HBV infection, TLRs may slow down HBV infection, but contribute only indirectly to viral clearance. Importantly, TLRs may modulate HBV-specific T- and B-cell responses in vivo, which are essential for the termination of HBV infection. Thus, TLR agonists are promising candidates to act as immunomodulators for the treatment of chronic HBV infection. Antiviral treatment may recover TLR expression and function in chronic HBV infection and may increase the efficacy of therapeutic approaches based on TLR activation. A combined therapeutic strategy with antiviral treatment and TLR activation could facilitate the restoration of HBV-specific immune responses and thereby, achieve viral clearance in chronically infected HBV patients. PMID:25418467

  17. Structural Basis for the Antiviral Activity of BST-2/Tetherin and Its Viral Antagonism

    PubMed Central

    Arias, Juan F.; Iwabu, Yukie; Tokunaga, Kenzo

    2011-01-01

    The interferon-inducible host restriction factor bone marrow stromal antigen 2 (BST-2/tetherin) blocks the release of HIV-1 and other enveloped viruses. In turn, these viruses have evolved specific antagonists to counteract this host antiviral molecule, such as the HIV-1 protein Vpu. BST-2 is a type II transmembrane protein with an unusual topology consisting of an N-terminal cytoplasmic tail (CT) followed by a single transmembrane (TM) domain, a coiled-coil extracellular (EC) domain, and a glycosylphosphatidylinositol (GPI) anchor at the C terminus. We and others showed that BST-2 restricts enveloped virus release by bridging the host and virion membranes with its two opposing membrane anchors and that deletion of either one completely abrogates antiviral activity. The EC domain also shows conserved structural properties that are required for antiviral function. It contains several destabilizing amino acids that confer the molecule with conformational flexibility to sustain the protein’s function as a virion tether, and three conserved cysteine residues that mediate homodimerization of BST-2, as well as acting as a molecular ruler that separates the membrane anchors. Conversely, the efficient release of virions is promoted by the HIV-1 Vpu protein and other viral antagonists. Our group and others provided evidence from mutational analyses indicating that Vpu antagonism of BST-2-mediated viral restriction requires a highly specific interaction of their mutual TM domains. This interpretation is further supported and expanded by the findings of the latest structural modeling studies showing that critical amino acids in a conserved helical face of these TM domains are required for Vpu–BST-2 interaction and antagonism. In this review, we summarize the current advances in our understanding of the structural basis for BST-2 antiviral function as well as BST-2-specific viral antagonism. PMID:22180752

  18. Immune Receptors and Co-receptors in Antiviral Innate Immunity in Plants

    PubMed Central

    Gouveia, Bianca C.; Calil, Iara P.; Machado, João Paulo B.; Santos, Anésia A.; Fontes, Elizabeth P. B.

    2017-01-01

    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

  19. Dufulin Activates HrBP1 to Produce Antiviral Responses in Tobacco

    PubMed Central

    Chen, Zhuo; Zeng, Mengjiao; Song, Baoan; Hou, Chengrui; Hu, Deyu; Li, Xiangyang; Wang, Zhenchao; Fan, Huitao; Bi, Liang; Liu, Jiaju; Yu, Dandan; Jin, Linhong; Yang, Song

    2012-01-01

    Background Dufulin is a new antiviral agent that is highly effective against plant viruses and acts by activating systemic acquired resistance (SAR) in plants. In recent years, it has been used widely to prevent and control tobacco and rice viral diseases in China. However, its targets and mechanism of action are still poorly understood. Methodology/Principal Findings Here, differential in-gel electrophoresis (DIGE) and classical two-dimensional electrophoresis (2-DE) techniques were combined with mass spectrometry (MS) to identify the target of Dufulin. More than 40 proteins were found to be differentially expressed (≥1.5 fold or ≤1.5 fold) upon Dufulin treatment in Nicotiana tabacum K326. Based on annotations in the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, these proteins were found to be related to disease resistance. Directed acyclic graph (DAG) analysis of the various pathways demonstrated harpin binding protein-1 (HrBP1) as the target of action of Dufulin. Additionally, western blotting, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), and real time PCR analyses were also conducted to identify the specific mechanism of action of Dufulin. Our results show that activation of HrBP1 triggers the salicylic acid (SA) signaling pathway and thereby produces antiviral responses in the plant host. A protective assay based on lesion counting further confirmed the antiviral activity of Dufulin. Conclusion This study identified HrBP1 as a target protein of Dufulin and that Dufulin can activate the SA signaling pathway to induce host plants to generate antiviral responses. PMID:22662252

  20. Progress in RNAi-based antiviral therapeutics.

    PubMed

    Zhou, Jiehua; Rossi, John J

    2011-01-01

    RNA interference (RNAi) refers to the conserved sequence-specific degradation of message RNA mediated by small interfering (si)RNA duplexes 21-25 nucleotides in length. Given the ability to specifically silence any gene of interest, siRNAs offers several advantages over conventional drugs as potential therapeutic agents for the treatment of human maladies including cancers, genetic disorders, and infectious diseases. Antiviral RNAi strategies have received much attention and several compounds are currently being tested in clinical trials. In particular, the development of siRNA-based HIV (human immunodeficiency virus) therapeutics has progressed rapidly and many recent studies have shown that the use of RNAi could inhibit HIV-1 replication by targeting a number of viral or cellular genes. Therefore, the present chapter mainly focuses on the recent progress of RNAi-based anti-HIV gene therapeutics, with particular attention to molecular targets and delivery strategies of the siRNAs.

  1. Cytoplasmic nucleic acid sensors in antiviral immunity.

    PubMed

    Ranjan, Priya; Bowzard, J Bradford; Schwerzmann, Joy W; Jeisy-Scott, Victoria; Fujita, Takashi; Sambhara, Suryaprakash

    2009-08-01

    The innate immune system uses pattern recognition receptors (PRRs) to sense invading microbes and initiate a rapid protective response. PRRs bind and are activated by structural motifs, such as nucleic acids or bacterial and fungal cell wall components, collectively known as pathogen-associated molecular patterns. PRRs that recognize pathogen-derived nucleic acids are present in vesicular compartments and in the cytosol of most cell types. Here, we review recent studies of these cytosolic sensors, focusing on the nature of the ligands for DNA-dependent activator of interferon (DAI)-regulatory factors, absent in melanoma 2 (AIM2), and the retinoic acid-inducible gene I-like helicase (RLH) family of receptors, the basis of ligand recognition and the signaling pathways triggered by the activation of these receptors. An increased understanding of these molecular aspects of innate immunity will guide the development of novel antiviral therapeutics.

  2. Contribution of autophagy to antiviral immunity.

    PubMed

    Rey-Jurado, Emma; Riedel, Claudia A; González, Pablo A; Bueno, Susan M; Kalergis, Alexis M

    2015-11-14

    Although identified in the 1960's, interest in autophagy has significantly increased in the past decade with notable research efforts oriented at understanding as to how this multi-protein complex operates and is regulated. Autophagy is commonly defined as a "self-eating" process evolved by eukaryotic cells to recycle senescent organelles and expired proteins, which is significantly increased during cellular stress responses. In addition, autophagy can also play important roles during human diseases, such as cancer, neurodegenerative and autoimmune disorders. Furthermore, novel findings suggest that autophagy contributes to the host defense against microbial infections. In this article, we review the role of macroautophagy in antiviral immune responses and discuss molecular mechanisms evolved by viral pathogens to evade this process. A role for autophagy as an effector mechanism used both, by innate and adaptive immunity is also discussed.

  3. RNA degradation in antiviral immunity and autoimmunity

    PubMed Central

    Rigby, Rachel E.; Rehwinkel, Jan

    2015-01-01

    Post-transcriptional control determines the fate of cellular RNA molecules. Nonsense-mediated decay (NMD) provides quality control of mRNA, targeting faulty cellular transcripts for degradation by multiple nucleases including the RNA exosome. Recent findings have revealed a role for NMD in targeting viral RNA molecules, thereby restricting virus infection. Interestingly, NMD is also linked to immune responses at another level: mutations affecting the NMD or RNA exosome machineries cause chronic activation of defence programmes, resulting in autoimmune phenotypes. Here we place these observations in the context of other links between innate antiviral immunity and type I interferon mediated disease and examine two models: one in which expression or function of pathogen sensors is perturbed and one wherein host-derived RNA molecules with a propensity to activate such sensors accumulate. PMID:25709093

  4. The antiviral lectin cyanovirin-N: probing multivalency and glycan recognition through experimental and computational approaches.

    PubMed

    Woodrum, Brian W; Maxwell, Jason D; Bolia, Ashini; Ozkan, S Banu; Ghirlanda, Giovanna

    2013-10-01

    CVN (cyanovirin-N), a small lectin isolated from cyanobacteria, exemplifies a novel class of anti-HIV agents that act by binding to the highly glycosylated envelope protein gp120 (glycoprotein 120), resulting in inhibition of the crucial viral entry step. In the present review, we summarize recent work in our laboratory and others towards determining the crucial role of multivalency in the antiviral activity, and we discuss features that contribute to the high specificity and affinity for the glycan ligand observed in CVN. An integrated approach that encompasses structural determination, mutagenesis analysis and computational work holds particular promise to clarify aspects of the interactions between CVN and glycans.

  5. Antifungal and antiviral products of marine organisms

    PubMed Central

    Cheung, Randy Chi Fai; Pan, Wen Liang; Chan, Yau Sang; Yin, Cui Ming; Dan, Xiu Li; Wang, He Xiang; Fang, Evandro Fei; Lam, Sze Kwan; Ngai, Patrick Hung Kui; Xia, Li Xin; Liu, Fang; Ye, Xiu Yun; Zhang, Guo Qing; Liu, Qing Hong; Sha, Ou; Lin, Peng; Ki, Chan; Bekhit, Adnan A; Bekhit, Alaa El-Din; Wan, David Chi Cheong

    2017-01-01

    Marine organisms including bacteria, fungi, algae, sponges, echinoderms, mollusks, and cephalochordates produce a variety of products with antifungal activity including bacterial chitinases, lipopeptides, and lactones; fungal (−)-sclerotiorin and peptaibols, purpurides B and C, berkedrimane B and purpuride; algal gambieric acids A and B, phlorotannins; 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol, spongistatin 1, eurysterols A and B, nortetillapyrone, bromotyrosine alkaloids, bis-indole alkaloid, ageloxime B and (−)-ageloxime D, haliscosamine, hamigeran G, hippolachnin A from sponges; echinoderm triterpene glycosides and alkene sulfates; molluscan kahalalide F and a 1485-Da peptide with a sequence SRSELIVHQR; and cepalochordate chitotriosidase and a 5026.9-Da antifungal peptide. The antiviral compounds from marine organisms include bacterial polysaccharide and furan-2-yl acetate; fungal macrolide, purpurester A, purpurquinone B, isoindolone derivatives, alterporriol Q, tetrahydroaltersolanol C and asperterrestide A, algal diterpenes, xylogalactofucan, alginic acid, glycolipid sulfoquinovosyldiacylglycerol, sulfated polysaccharide p-KG03, meroditerpenoids, methyl ester derivative of vatomaric acid, lectins, polysaccharides, tannins, cnidarian zoanthoxanthin alkaloids, norditerpenoid and capilloquinol; crustacean antilipopolysaccharide factors, molluscan hemocyanin; echinoderm triterpenoid glycosides; tunicate didemnin B, tamandarins A and B and; tilapia hepcidin 1–5 (TH 1–5), seabream SauMx1, SauMx2, and SauMx3, and orange-spotted grouper β-defensin. Although the mechanisms of antifungal and antiviral activities of only some of the afore-mentioned compounds have been elucidated, the possibility to use those known to have distinctly different mechanisms, good bioavailability, and minimal toxicity in combination therapy remains to be investigated. It is also worthwhile to test the marine antimicrobials for possible synergism with existing drugs. The

  6. Cherry Valley Ducks Mitochondrial Antiviral-Signaling Protein-Mediated Signaling Pathway and Antiviral Activity Research

    PubMed Central

    Li, Ning; Hong, Tianqi; Li, Rong; Wang, Yao; Guo, Mengjiao; Cao, Zongxi; Cai, Yumei; Liu, Sidang; Chai, Tongjie; Wei, Liangmeng

    2016-01-01

    Mitochondrial antiviral-signaling protein (MAVS), an adaptor protein of retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs)-mediated signal pathway, is involved in innate immunity. In this study, Cherry Valley duck MAVS (duMAVS) was cloned from the spleen and analyzed. duMAVS was determined to have a caspase activation and recruitment domain at N-terminal, followed by a proline-rich domain and a transmembrane domain at C-terminal. Quantitative real-time PCR indicated that duMAVS was expressed in all tissues tested across a broad expression spectrum. The expression of duMAVS was significantly upregulated after infection with duck Tembusu virus (DTMUV). Overexpression of duMAVS could drive the activation of interferon (IFN)-β, nuclear factor-κB, interferon regulatory factor 7, and many downstream factors (such as Mx, PKR, OAS, and IL-8) in duck embryo fibroblast cells. What is more, RNA interference further confirmed that duMAVS was an important adaptor for IFN-β activation. The antiviral assay showed that duMAVS could suppress the various viral replications (DTMUV, novel reovirus, and duck plague virus) at early stages of infection. Overall, these results showed that the main signal pathway mediated by duMAVS and it had a broad-spectrum antiviral ability. This research will be helpful to better understanding the innate immune system of ducks. PMID:27708647

  7. Privacy Act

    EPA Pesticide Factsheets

    Learn about the Privacy Act of 1974, the Electronic Government Act of 2002, the Federal Information Security Management Act, and other information about the Environmental Protection Agency maintains its records.

  8. Sulfated polysaccharides extracted from sea algae as potential antiviral drugs.

    PubMed

    Witvrouw, M; De Clercq, E

    1997-10-01

    also play an important role. Sulfated polysaccharides may act synergistically with other anti-HIV drugs (e.g., azidothymidine [AZT]). They are known to lead very slowly to virus-drug resistance development and they show activity against HIV mutants that have become resistant to reverse transcriptase inhibitors, such as AZT, tetrahydro-imidazo [4,5,l-jk] [1,4]-benzodiazepin-2(1H)-thione (TIBO) and others. From studies on their mechanism of action we concluded that polysulfates exert their anti-HIV activity by shielding off the positively charged sites in the V3 loop of the viral envelope glycoprotein (gp120). The V3 loop is necessary for virus attachment to cell surface heparan sulfate, a primary binding site, before more specific binding occurs to the CD4 receptor of CD4+ cells. This general mechanism also explains the broad antiviral activity of polysulfates against enveloped viruses. Variations in the viral envelope glycoprotein region may result in differences in the susceptibility of different enveloped viruses to compounds that interact with their envelope glycoproteins. The efficacy of polysulfates in the therapy and/or prophylaxis of retroviral infections and opportunistic infections remains to be demonstrated both in animal models and humans. It is important to consider not only treatment of patients who are already infected with HIV, but also prophylaxis and protection from HIV and/or other virus infections. Because (i) sexual transmission is responsible for the large majority of HIV infections worldwide; (ii) this transmission is mostly mediated via mononuclear cells that infect epithelial cells of the genital tract; and because (iii) polysulfates effectively inhibit cell-cell adhesion, polysulfates may be considered as potentially effective in a vaginal formulation to protect against HIV infection.

  9. Hepatitis C Virus Experimental Model Systems and Antiviral drug Research*

    PubMed Central

    Uprichard, Susan L.

    2010-01-01

    An estimated 130 million people worldwide are chronically infected with hepatitis C virus (HCV) making it a leading cause of liver disease worldwide. Because the currently available therapy of pegylated interferon-alpha and ribavirin is only effective in a subset of patients, the development of new HCV antivirals is a healthcare imperative. This review discusses the experimental models available for HCV antiviral drug research, recent advances in HCV antiviral drug development, as well as active research being pursued to facilitate development of new HCV-specific therapeutics. PMID:20960298

  10. Antiviral chemotherapy in veterinary medicine: current applications and perspectives.

    PubMed

    Dal Pozzo, F; Thiry, E

    2014-12-01

    The current situation in the use of antiviral drugs in veterinary medicine is characterised by a novel and optimistic approach.Viruses of veterinary importance are still used as animal models in the developmentof human therapeutics, but there is growing interest in many of these viruses in the identification of antiviral molecules for use in both livestock and companion animals. The use of antiviral drugs in livestock animals is envisaged for the treatment or control of disease on a large scale (mass treatment), whereas in companion animals an individual approach is favoured. An overview of the most recent examples of research in the use of antivirals in veterinary medicine is presented, with particular emphasis on their in vivo applications.

  11. International society for antiviral research - 23rd international conference.

    PubMed

    Mason, Vicki L

    2010-06-01

    The 23rd International Conference on Antiviral Research (ICAR), organized by the International Society for Antiviral Research (ISAR) and held in San Francisco, included topics covering new therapeutic developments in the field of antivirals. This conference report highlights selected presentations on CD4-BFFI (Roche Holding AG), a CD4 mAb-based bifunctional HIV entry inhibitor; a CLDC-HBsAg vaccine (Juvaris BioTherapeutics Inc/China National Biotec Group) against HBV; ODE-(S)-MPMPA (University of California San Diego), a potent anti-HCV compound; the anti-human CMV activity exhibited by tricin; the protective activity of Ingavirin against influenza A; and Prosetta Bioconformatics's approach to identifying small-molecule antivirals.

  12. Antiviral agents against equid alphaherpesviruses: Current status and perspectives.

    PubMed

    Vissani, María A; Thiry, Etienne; Dal Pozzo, Fabiana; Barrandeguy, María

    2016-01-01

    Equid herpesvirus infections cause respiratory, neurological and reproductive syndromes. Despite preventive and control measures and the availability of vaccines and immunostimulants, herpesvirus infections still constitute a major threat to equine health and for the equine industry worldwide. Antiviral drugs, particularly nucleoside analogues and foscarnet, are successfully used for the treatment of human alphaherpesvirus infections. In equine medicine, the use of antiviral medications in alphaherpesvirus infections would decrease the excretion of virus and diminish the risk of contagion and the convalescent time in affected horses, and would also improve the clinical outcome of equine herpesvirus myeloencephalopathy. The combined use of antiviral compounds, along with vaccines, immune modulators, and effective preventive and control measures, might be beneficial in diminishing the negative impact of alphaherpesvirus infections in horses. The purpose of this review is to analyse the available information regarding the use of antiviral agents against alphaherpesviruses, with particular emphasis on equine alphaherpesvirus infections.

  13. Dengue Virus Entry as Target for Antiviral Therapy

    PubMed Central

    Alen, Marijke M. F.; Schols, Dominique

    2012-01-01

    Dengue virus (DENV) infections are expanding worldwide and, because of the lack of a vaccine, the search for antiviral products is imperative. Four serotypes of DENV are described and they all cause a similar disease outcome. It would be interesting to develop an antiviral product that can interact with all four serotypes, prevent host cell infection and subsequent immune activation. DENV entry is thus an interesting target for antiviral therapy. DENV enters the host cell through receptor-mediated endocytosis. Several cellular receptors have been proposed, and DC-SIGN, present on dendritic cells, is considered as the most important DENV receptor until now. Because DENV entry is a target for antiviral therapy, various classes of compounds have been investigated to inhibit this process. In this paper, an overview is given of all the putative DENV receptors, and the most promising DENV entry inhibitors are discussed. PMID:22529868

  14. Zika virus: a race in search for antivirals.

    PubMed

    Saiz, Juan-Carlos; Martín-Acebes, Miguel A

    2017-03-27

    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 fetus and newborns). Nowadays, no specific antiviral therapy is available against ZIKV. However, during the past months, a great effort has been made in search for antiviral candidates by using different approaches and methodologies, from testing specific compounds with known antiviral activity to screenings 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.

  15. Potential Antiviral Agents from Marine Fungi: An Overview.

    PubMed

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

    2015-07-22

    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.

  16. 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

  17. Antiviral Efficacy of Pyrazofurin against Selected RNA Viruses

    DTIC Science & Technology

    1982-03-24

    DTIC Antiviral Research, 2 (1982) 33-337 ELECTE31 Elsevier Biomedical Press JUN t4 s ANTIVIRAL EFFICACY OF PYRAZOFURIN AGAINST SELECTED RNA VIRUSES ...hydroxypyrazole-5-carboxamide, markedly inhibited the in vitro replication of a number of RNA viruses including Rift Valley fever (RVF), S Venezuelan equine...encephalomyelitis (VEE), Sandfly, Pichinde, Lassa and LCM virus . Plaque forma- tion was reduced by 80% or more with 2-10 pg/ml of pyrazofurin while 2 ug

  18. Hepatitis C viral protein translation: mechanisms and implications in developing antivirals.

    PubMed

    Hoffman, Brett; Liu, Qiang

    2011-11-01

    Hepatitis C viral protein translation occurs in a cap-independent manner through the use of an internal ribosomal entry site (IRES) present within the viral 5'-untranslated region. The IRES is composed of highly conserved structural domains that directly recruit the 40S ribosomal subunit to the viral genomic RNA. This frees the virus from relying on a large number of translation initiation factors that are required for cap-dependent translation, conferring a selective advantage to the virus especially in times when the availability of such factors is low. Although the mechanism of translation initiation on the Hepatitis C virus (HCV) IRES is well established, modulation of the HCV IRES activity by both cellular and viral factors is not well understood. As the IRES is essential in the HCV life cycle and as such remains well conserved in an otherwise highly heterogenic virus, the process of HCV protein translation represents an attractive target in the development of novel antivirals. This review will focus on the mechanisms of HCV protein translation and how this process is postulated to be modulated by cis-acting viral factors, as well as trans-acting viral and cellular factors. Numerous therapeutic approaches investigated in targeting HCV protein translation for the development of novel antivirals will also be discussed.

  19. Antiviral activities of coffee extracts in vitro.

    PubMed

    Utsunomiya, Hirotoshi; Ichinose, Masao; Uozaki, Misao; Tsujimoto, Kazuko; Yamasaki, Hisashi; Koyama, A Hajime

    2008-06-01

    Both hot water extracts of coffee grinds and instant coffee solutions inhibited the multiplication of herpes simplex virus type 1, a representative enveloped DNA virus, when they were added to the culture medium of the virus-infected cells at a dose of one fifth the concentration suitable for drinking. The antiherpetic activity was independent of the suppliers (companies) of the coffee grinds and of the locations where the coffee beans were produced. Further characterization revealed that there are two different mechanisms, by which the coffee extracts exert inhibitory activities on the virus infection; (1) a direct inactivation of the infectivity of virus particle (i.e., a virucidal activity) and (2) the inhibition of progeny infectious virus formation at the late stage of viral multiplication in the infected cells. Caffeine, but not quinic acid and chlorogenic acid, inhibited the virus multiplication to some extent, but none of them showed the virucidal activity, suggesting that other component(s) in the coffee extracts must play a role in the observed antiviral activity. In addition, the coffee extracts inhibited the multiplication of poliovirus, a non-enveloped RNA virus, but showed no virucidal effect on this virus.

  20. Protein modification during antiviral heat bioprocessing.

    PubMed

    Smales, C M; Pepper, D S; James, D C

    2000-01-20

    Heat treatment is routinely used in the preparation of therapeutic protein biopharmaceuticals as a means of viral inactivation. However, in undertaking virucidal heat treatments, a balance must be found between the bioprocessing conditions, virus kill, and the maintenance of protein integrity. In this study, we utilize a simple model protein, hen egg-white lysozyme, to investigate the relationship between antiviral bioprocess conditions (protein formulation and temperature) and the extent and type of protein modification. A variety of industrially relevant wet- and dry-heat treatments were undertaken, using formulations that included sucrose as a thermostabilizing excipient. Although there was no evidence of lysozyme aggregation or crosslinking during any of the heat treatments, using liquid chromatography-electrospray ionization-mass spectroscopy (LC-ESI-MS) and peptide mapping we show that protein modifications do occur with increasingly harsh heat treatment. Modifications were predominantly found after wet-heat treatment, the major covalent modification of lysozyme under these conditions being glycation of Lys(97), by either glucose or fructose derived from hydrolyzed sucrose. The extent of sucrose hydrolysis was itself dependent on both the duration of heat treatment and formulation composition. Advanced glycation end products (AGEs) and additional unidentified products were also present in protein samples subjected to extended heat treatment. AGEs were derived primarily from initial glycation by fructose and not glucose. These findings have implications for the improvement of bioprocesses to ensure protein product quality.

  1. An Image-Based Genetic Assay Identifies Genes in T1D Susceptibility Loci Controlling Cellular Antiviral Immunity in Mouse

    PubMed Central

    Liao, Juan; Jijon, Humberto B.; Kim, Ira R.; Goel, Gautam; Doan, Aivi; Sokol, Harry; Bauer, Hermann; Herrmann, Bernhard G.; Lassen, Kara G.; Xavier, Ramnik J.

    2014-01-01

    The pathogenesis of complex diseases, such as type 1 diabetes (T1D), derives from interactions between host genetics and environmental factors. Previous studies have suggested that viral infection plays a significant role in initiation of T1D in genetically predisposed individuals. T1D susceptibility loci may therefore be enriched in previously uncharacterized genes functioning in antiviral defense pathways. To identify genes involved in antiviral immunity, we performed an image-based high-throughput genetic screen using short hairpin RNAs (shRNAs) against 161 genes within T1D susceptibility loci. RAW 264.7 cells transduced with shRNAs were infected with GFP-expressing herpes simplex virus type 1 (HSV-1) and fluorescent microscopy was performed to assess the viral infectivity by fluorescence reporter activity. Of the 14 candidates identified with high confidence, two candidates were selected for further investigation, Il27 and Tagap. Administration of recombinant IL-27 during viral infection was found to act synergistically with interferon gamma (IFN-γ) to activate expression of type I IFNs and proinflammatory cytokines, and to enhance the activities of interferon regulatory factor 3 (IRF3). Consistent with a role in antiviral immunity, Tagap-deficient macrophages demonstrated increased viral replication, reduced expression of proinflammatory chemokines and cytokines, and decreased production of IFN-β. Taken together, our unbiased loss-of-function genetic screen identifies genes that play a role in host antiviral immunity and delineates roles for IL-27 and Tagap in the production of antiviral cytokines. PMID:25268627

  2. Systems Biology-Based Investigation of Cellular Antiviral Drug Targets Identified by Gene-Trap Insertional Mutagenesis

    PubMed Central

    Zhao, Junfei; Sheng, Jinsong; Rubin, Donald H.

    2016-01-01

    Viruses require host cellular factors for successful replication. A comprehensive systems-level investigation of the virus-host interactome is critical for understanding the roles of host factors with the end goal of discovering new druggable antiviral targets. Gene-trap insertional mutagenesis is a high-throughput forward genetics approach to randomly disrupt (trap) host genes and discover host genes that are essential for viral replication, but not for host cell survival. In this study, we used libraries of randomly mutagenized cells to discover cellular genes that are essential for the replication of 10 distinct cytotoxic mammalian viruses, 1 gram-negative bacterium, and 5 toxins. We herein reported 712 candidate cellular genes, characterizing distinct topological network and evolutionary signatures, and occupying central hubs in the human interactome. Cell cycle phase-specific network analysis showed that host cell cycle programs played critical roles during viral replication (e.g. MYC and TAF4 regulating G0/1 phase). Moreover, the viral perturbation of host cellular networks reflected disease etiology in that host genes (e.g. CTCF, RHOA, and CDKN1B) identified were frequently essential and significantly associated with Mendelian and orphan diseases, or somatic mutations in cancer. Computational drug repositioning framework via incorporating drug-gene signatures from the Connectivity Map into the virus-host interactome identified 110 putative druggable antiviral targets and prioritized several existing drugs (e.g. ajmaline) that may be potential for antiviral indication (e.g. anti-Ebola). In summary, this work provides a powerful methodology with a tight integration of gene-trap insertional mutagenesis testing and systems biology to identify new antiviral targets and drugs for the development of broadly acting and targeted clinical antiviral therapeutics. PMID:27632082

  3. Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity.

    PubMed

    Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn; Tajima, Shigeru; Hikono, Hirokazu; Saito, Takehiko; Aida, Yoko

    2014-07-18

    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 a 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 IC50 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.

  4. [Renewed 2015 Clinical Practice Guidelines for Management of Hepatitis C by Korean Association for the Study of the Liver; What Has Been Changed? - Treatment of Chronic Hepatitis C Genotype 2 and 3].

    PubMed

    Jung, Young Kul

    2016-03-01

    Ever since direct-acting antiviral agents (DAA) have been approved and released into the world, numerous studies on the efficacy, adverse effects and drug-drug interactions of interferon-free DAA combination therapy have been studied and published. With all oral DAA therapy showing sustained virological response rate of 80-90% with minimal adverse events, HCV eradication has now become a realistic goal. DAA combination treatments were approved and adapted to practice in Korea in 2015, and Korean Association for the Study of the Liver (KASL) has revised the guideline based on the systematic approach that reflects evidence-based medicine and expert opinions. In this article, new recommendations for treatment of chronic HCV genotype 2 and 3 infected patients will be introduced base on KASL practice guidelines for management of hepatitis C that has been updated in 2015.

  5. Antiviral effect of ranpirnase against Ebola virus.

    PubMed

    Hodge, Thomas; Draper, Ken; Brasel, Trevor; Freiberg, Alexander; Squiquera, Luis; Sidransky, David; Sulley, Jamie; Taxman, Debra J

    2016-08-01

    The recent epidemic of Ebola has intensified the need for the development of novel antiviral therapeutics that prolong and improve survival against deadly viral diseases. We sought to determine whether ranpirnase, an endoribonuclease from Rana pipiens with a demonstrated human safety profile in phase III oncology trials, can reduce titers of Ebola virus (EBOV) in infected cells, protect mice against mouse-adapted EBOV challenge, and reduce virus levels in infected mice. Our results demonstrate that 0.50 μg/ml ranpirnase is potently effective at reducing EBOV Zaire Kikwit infection in cultured Vero E6 cells (Selectivity Index 47.8-70.2). In a prophylactic study, a single intravenous dose of 0.1 mg/kg ranpirnase protected 70% of mice from progressive infection. Additionally, in a post-exposure prophylactic study, 100% of female mice survived infection after intraperitoneal administration of 0.1 mg/kg ranpirnase for ten days beginning 1 h post challenge. Most of the male counterparts were sacrificed due to weight loss by Study Day 8 or 9; however, the Clinical Activity/Behavior scores of these mice remained low and no significant microscopic pathologies could be detected in the kidneys, livers or spleens. Furthermore, live virus could not be detected in the sera of ranpirnase-treated mice by Study Day 8 or in the kidneys, livers or spleens by Study Day 12, and viral RNA levels declined exponentially by Study Day 12. Because ranpirnase is exceptionally stable and has a long track record of safe intravenous administration to humans, this drug provides a promising new candidate for clinical consideration in the treatment of Ebola virus disease alone or in combination with other therapeutics.

  6. Targeting viral dsRNA for antiviral prophylaxis

    PubMed Central

    Fei, Zhou; Liu, Yang; Yan, Zhen; Fan, Daiming; Alexander, Alice; Yang, Jing-Hua

    2011-01-01

    Double-stranded (ds)RNA in the infected cells is a trait shared by most if not all viruses. While humans have developed variable immune responses, viruses have also developed countermeasures to defeat dsRNA-induced antiviral strategies. Thus, we proposed a broad antiviral strategy to antagonize the countermeasures of viruses and bypass the dsRNA-induced signals that are readily defeated by viruses. By rewiring the dsRNA-binding proteins in the dsRNA complex and reconnecting them to apoptosis signaling, we created several dsRNA-dependent caspase recruiters, termed dsCAREs, to bypass dsRNA-induced antiviral signals that would otherwise be targeted by viruses. Adenovirus and vesicular stomatitis virus, representing viruses of the dsDNA and negative-stranded RNA viral groups, were used to infect HEK293 cells. The dsCARE chimera was added in medium to evaluate its antiviral activity. The truncated dsCAREs were used as controls. We demonstrate that dsCARE suppresses viral infection starting at 0.1 μg/ml and reaches the peak at 2 μg/ml. The EC50 was ∼0.2 μg/ml. However, it had an undetectable effect on uninfected cells. Further data show that both dsRNA binding and apoptosis activation of dsCARE are essential for its antiviral activity. We conclude that dsRNA is a practical virus-associated molecular pattern that can be targeted for broad and rapid antiviral prophylaxis.—Fei, Z., Liu, Y., Yan, Z., Fan, D., Alexander, A., Yang, J.-H. Targeting viral dsRNA for antiviral prophylaxis. PMID:19880628

  7. Identification of a novel multiple kinase inhibitor with potent antiviral activity against influenza virus by reducing viral polymerase activity

    SciTech Connect

    Sasaki, Yutaka; Kakisaka, Michinori; Chutiwitoonchai, Nopporn; Tajima, Shigeru; Hikono, Hirokazu; Saito, Takehiko; Aida, Yoko

    2014-07-18

    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 a 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.

  8. Antiviral activity of Paulownia tomentosa against enterovirus 71 of hand, foot, and mouth disease.

    PubMed

    Ji, Ping; Chen, Changmai; Hu, Yanan; Zhan, Zixuan; Pan, Wei; Li, Rongrong; Li, Erguang; Ge, Hui-Ming; Yang, Guang

    2015-01-01

    The bark, leaves, and flowers of Paulownia trees have been used in traditional Chinese medicine to treat infectious and inflammatory diseases. We investigated the antiviral effects of Paulownia tomentosa flowers, an herbal medicine used in some provinces of P. R. China for the treatment of skin rashes and blisters. Dried flowers of P. tomentosa were extracted with methanol and tested for antiviral activity against enterovirus 71 (EV71) and coxsackievirus A16 (CAV16), the predominant etiologic agents of hand, foot, and mouth disease in P. R. China. The extract inhibited EV71 infection, although no effect was detected against CAV16 infection. Bioactivity-guided fractionation was performed to identify apigenin as an active component of the flowers. The EC50 value for apigenin to block EV71 infection was 11.0 µM, with a selectivity index of approximately 9.3. Although it is a common dietary flavonoid, only apigenin, and not similar compounds like naringenin and quercetin, were active against EV71 infection. As an RNA virus, the genome of EV71 has an internal ribosome entry site that interacts with heterogeneous nuclear ribonucleoproteins (hnRNPs) and regulates viral translation. Cross-linking followed by immunoprecipitation and reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that EV71 RNA was associated with hnRNPs A1 and A2. Apigenin treatment disrupted this association, indicating that apigenin suppressed EV71 replication through a novel mechanism by targeting the trans-acting factors. This study therefore validates the effects of Paulownia against EV71 infection. It also yielded mechanistic insights on apigenin as an active compound for the antiviral activity of P. tomentosa against EV71 infection.

  9. Screening for antiviral activities of isolated compounds from essential oils.

    PubMed

    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.

  10. 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.

  11. Recent developments in antiviral agents against enterovirus 71 infection

    PubMed Central

    2014-01-01

    Enterovirus 71 (EV-71) is the main etiological agent of hand, foot and mouth disease (HFMD). Recent EV-71 outbreaks in Asia-Pacific were not limited to mild HFMD, but were associated with severe neurological complications such as aseptic meningitis and brainstem encephalitis, which may lead to cardiopulmonary failure and death. The absence of licensed therapeutics for clinical use has intensified research into anti-EV-71 development. This review highlights the potential antiviral agents targeting EV-71 attachment, entry, uncoating, translation, polyprotein processing, virus-induced formation of membranous RNA replication complexes, and RNA-dependent RNA polymerase. The strategies for antiviral development include target-based synthetic compounds, anti-rhinovirus and poliovirus libraries screening, and natural compound libraries screening. Growing knowledge of the EV-71 life cycle will lead to successful development of antivirals. The continued effort to develop antiviral agents for treatment is crucial in the absence of a vaccine. The coupling of antivirals with an effective vaccine will accelerate eradication of the disease. PMID:24521134

  12. Antiviral therapy for hepatitis B virus-related decompensated cirrhosis.

    PubMed

    Wang, Ji Yao

    2012-11-01

    Antiviral therapy is important in patients with hepatitis B virus (HBV)-related decompensated cirrhosis. This therapy is beneficial in most patients for the stabilization or improvement of liver disease; however, advanced cirrhosis with a high Child-Pugh or model for end-stage liver disease (MELD) score may have progressed and does not benefit from antiviral therapy. It is important to identify patients with severe decompensated cirrhosis who will not improve under antiviral therapy and who require liver transplantation as early as possible. Entecavir (ETV) or tenofovir disoproxil fumarate (TDF) is the first-line therapy for nucleos(t)ide analogue (NA)-naive patients with decompensated cirrhosis due to their potent and prompt HBV suppressive effect and low rate of drug-resistant mutations. Patients on antiviral therapy should be monitored for virological and clinical response, compliance, drug resistance and adverse effects as well as surveillance for hepatocellular carcinoma (HCC). Additional studies of TDF and ETV are necessary to determine the optimal agent(s) for treating naive patients and those with drug-resistant decompensated cirrhosis. In order to evaluate the effectiveness of NA for the treatment of decompensated cirrhotic patients in the real world, high quality observational studies such as registration studies of antiviral therapy for HBV-related cirrhosis and a long-term follow-up in China, where a large number of such patients are found, are recommended.

  13. Antiviral Screening of Multiple Compounds against Ebola Virus

    PubMed Central

    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.

    2016-01-01

    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. PMID:27801778

  14. AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM FUNICULOSUM

    PubMed Central

    Shope, Richard E.

    1953-01-01

    A culture of P. funiculosum isolated on Guam proved capable of elaborating a substance which exerted a favorable therapeutic effect against swine influenza virus infections in white mice. The culture was extremely variable and irregular in its production of the antiviral substance, and during maintenance in the laboratory for several years gradually lost this property. Efforts to restore it were unsuccessful. Subsequently it was found that the mold elaborated a substance, now designated helenine, which is therapeutically effective against Columbia SK encephalomyelitis virus infections in mice. Helenine appears to differ from the substance earlier procured from the mold, which was active against swine influenza virus infections in mice. It is frequently present in greater or lesser amount in the fluid portions of stationary cultures of P. funiculosum but is more regularly obtained and in larger amount, from the cellular components of the pellicles. When liberated from these latter by mechanical bruising and fracturing, it goes into solution in the culture fluids. It is precipitable from aqueous solution by 50 per cent acetone. Infected mice injected with helenine in amounts less than the amount which produces a maximal therapeutic effect exhibit a dosage response. Increasing the dose above the optimum fails to increase the therapeutic effect. Helenine exerts its maximum effect when given within the first 10 hours after viral infection but its influence is apparent even when treatment is delayed for up to 24 hours. It is not effective against massive amounts of virus and gives the best therapeutic results when used in the treatment of animals infected with from 10 to 1000 fatal doses of virus. Treatment of infected mice with helenine delays the entrance of virus into their brains for from 24 to 48 hours. The mechanism by which helenine exerts its therapeutic effect against SK virus is not known but the findings presented suggest either that it causes an inhibition or

  15. Antiviral selection in the management of acute retinal necrosis

    PubMed Central

    Tam, Patrick MK; Hooper, Claire Y; Lightman, Susan

    2010-01-01

    There is no consensus on the optimal antiviral regimen in the management of acute retinal necrosis, a disease caused by herpetic viruses with devastating consequences for the eye. The current gold standard is based on retrospective case series. Because the incidence of disease is low, few well-designed, randomized trials have evaluated treatment dosage and duration. Newer oral antiviral agents are emerging as alternatives to high-dose intravenous acyclovir, avoiding the need for inpatient intravenous treatment. Drug resistance is uncommon but may also be difficult to identify. Antiviral drugs have few side effects, but special attention needs to be paid to patients who have underlying renal disease, are pregnant or are immunocompromised. PMID:20169044

  16. Host cell factors as antiviral targets in arenavirus infection.

    PubMed

    Linero, Florencia N; Sepúlveda, Claudia S; Giovannoni, Federico; Castilla, Viviana; García, Cybele C; Scolaro, Luis A; Damonte, Elsa B

    2012-09-01

    Among the members of the Arenaviridae family, Lassa virus and Junin virus generate periodic annual outbreaks of severe human hemorrhagic fever (HF) in endemic areas of West Africa and Argentina, respectively. Given the human health threat that arenaviruses represent and the lack of a specific and safe chemotherapy, the search for effective antiviral compounds is a continuous demanding effort. Since diverse host cell pathways and enzymes are used by RNA viruses to fulfill their replicative cycle, the targeting of a host process has turned an attractive antiviral approach in the last years for many unrelated virus types. This strategy has the additional benefit to reduce the serious challenge for therapy of RNA viruses to escape from drug effects through selection of resistant variants triggered by their high mutation rate. This article focuses on novel strategies to identify inhibitors for arenavirus therapy, analyzing the potential for antiviral developments of diverse host factors essential for virus infection.

  17. 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

  18. Cationic phenylene ethynylene polymers and oligomers exhibit efficient antiviral activity.

    PubMed

    Wang, Ying; Canady, Taylor D; Zhou, Zhijun; Tang, Yanli; Price, Dominique N; Bear, David G; Chi, Eva Y; Schanze, Kirk S; Whitten, David G

    2011-07-01

    The antiviral activities of poly(phenylene ethynylene) (PPE)-based cationic conjugated polyelectrolytes (CPE) and oligo-phenylene ethynylenes (OPE) were investigated using two model viruses, the T4 and MS2 bacteriophages. Under UV/visible light irradiation, significant antiviral activity was observed for all of the CPEs and OPEs; without irradiation, most of these compounds exhibited high inactivation activity against the MS2 phage and moderate inactivation ability against the T4 phage. Transmission electron microscopy (TEM) and SDS polyacrylamide gel electrophoresis (SDS-PAGE) reveal that the CPEs and OPEs exert their antiviral activity by partial disassembly of the phage particle structure in the dark and photochemical damage of the phage capsid protein under UV/visible light irradiation.

  19. 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.

  20. Antiviral defense in shrimp: from innate immunity to viral infection.

    PubMed

    Wang, Pei-Hui; Huang, Tianzhi; Zhang, Xiaobo; He, Jian-Guo

    2014-08-01

    The culture of penaeid shrimp is rapidly developing as a major business endeavor worldwide. However, viral diseases have caused huge economic loss in penaeid shrimp culture industries. Knowledge of shrimp innate immunity and antiviral responses has made important progress in recent years, allowing the design of better strategies for the prevention and control of shrimp diseases. In this study, we have updated information on shrimp antiviral immunity and interactions between shrimp hosts and viral pathogens. Current knowledge and recent progress in immune signaling pathways (e.g., Toll/IMD-NF-κB and JAK-STAT signaling pathways), RNAi, phagocytosis, and apoptosis in shrimp antiviral immunity are discussed. The mechanism of viral infection in shrimp hosts and the interactions between viruses and shrimp innate immune systems are also analyzed.

  1. Vitamin D and the anti-viral state

    PubMed Central

    Beard, Jeremy A.; Bearden, Allison; Striker, Rob

    2012-01-01

    Vitamin D has long been recognized as essential to the skeletal system. Newer evidence suggests that it also plays a major role regulating the immune system, perhaps including immune responses to viral infection. Interventional and observational epidemiological studies provide evidence that vitamin D deficiency may confer increased risk of influenza and respiratory tract infection. Vitamin D deficiency is also prevalent among patients with HIV infection. Cell culture experiments support the thesis that vitamin D has direct anti-viral effects particularly against enveloped viruses. Though vitamin D’s anti-viral mechanism has not been fully established, it may be linked to vitamin D’s ability to up-regulate the anti-microbial peptides LL-37 and human beta defensin 2. Additional studies are necessary to fully elucidate the efficacy and mechanism of vitamin D as an anti-viral agent. PMID:21242105

  2. [Favipiravir, a new concept of antiviral drug against influenza viruses].

    PubMed

    Reina, J; Reina, N

    2017-04-01

    Favipiravir (T-705) is a new antiviral drug with strong inhibitory activity on RNA-dependent RNA polymerase of most RNA virus genome. All the influenza viruses have been shown fully sensitive to this new antiviral, including genetic strains to neuraminidase inhibitors (oseltamivir) resistance. Its mechanism of action lies in blocking viral replication and induction of lethal mutagenesis which determines the loss of infective activity of influenza viruses. Its activity is particularly intense in the respiratory tract, decreasing the viral load to non-infectious levels. Clinical trials in humans have not yet completed but have very favourable results. It seems that the best therapy would be the combination of favipiravir with oseltamivir; both antivirals are synergistic and avoid the emergence of resistance.

  3. Commensal bacteria calibrate the activation threshold of innate antiviral immunity.

    PubMed

    Abt, Michael C; Osborne, Lisa C; Monticelli, Laurel A; Doering, Travis A; Alenghat, Theresa; Sonnenberg, Gregory F; Paley, Michael A; Antenus, Marcelo; Williams, Katie L; Erikson, Jan; Wherry, E John; Artis, David

    2012-07-27

    Signals from commensal bacteria can influence immune cell development and susceptibility to infectious or inflammatory diseases. However, the mechanisms by which commensal bacteria regulate protective immunity after exposure to systemic pathogens remain poorly understood. Here, we demonstrate that antibiotic-treated (ABX) mice exhibit impaired innate and adaptive antiviral immune responses and substantially delayed viral clearance after exposure to systemic LCMV or mucosal influenza virus. Furthermore, ABX mice exhibited severe bronchiole epithelial degeneration and increased host mortality after influenza virus infection. Genome-wide transcriptional profiling of macrophages isolated from ABX mice revealed decreased expression of genes associated with antiviral immunity. Moreover, macrophages from ABX mice exhibited defective responses to type I and type II IFNs and impaired capacity to limit viral replication. Collectively, these data indicate that commensal-derived signals provide tonic immune stimulation that establishes the activation threshold of the innate immune system required for optimal antiviral immunity.

  4. 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.

  5. Commensal Bacteria Calibrate the Activation Threshold of Innate Antiviral Immunity

    PubMed Central

    Abt, Michael C.; Osborne, Lisa C.; Monticelli, Laurel A.; Doering, Travis A.; Alenghat, Theresa; Sonnenberg, Gregory F.; Paley, Michael A.; Antenus, Marcelo; Williams, Katie L.; Erikson, Jan; Wherry, E. John; Artis, David

    2013-01-01

    SUMMARY Signals from commensal bacteria can influence immune cell development and susceptibility to infectious or inflammatory diseases. However, the mechanisms by which commensal bacteria regulate protective immunity after exposure to systemic pathogens remain poorly understood. Here, we demonstrate that antibiotic-treated (ABX) mice exhibit impaired innate and adaptive antiviral immune responses and substantially delayed viral clearance after exposure to systemic LCMV or mucosal influenza virus. Furthermore, ABX mice exhibited severe bronchiole epithelial degeneration and increased host mortality after influenza virus infection. Genome-wide transcriptional profiling of macrophages isolated from ABX mice revealed decreased expression of genes associated with antiviral immunity. Moreover, macrophages from ABX mice exhibited defective responses to type I and type II IFNs and impaired capacity to limit viral replication. Collectively, these data indicate that commensal-derived signals provide tonic immune stimulation that establishes the activation threshold of the innate immune system required for optimal antiviral immunity. PMID:22705104

  6. Antiviral therapy for hepatitis C: Has anything changed for pregnant/lactating women?

    PubMed Central

    Spera, Anna Maria; Eldin, Tarek Kamal; Tosone, Grazia; Orlando, Raffaele

    2016-01-01

    Hepatitis C virus (HCV) affects about 3% of the world’s population, with the highest prevalence in individuals under 40. The prevalence in pregnant women varies with geographical distribution (highest in developing countries). Prevalence also increases in sub-populations of women at high risk for blood-transmitted infections. HCV infection in pregnancy represents a non-negligible problem. However, most of the past antiviral regimens cannot be routinely offered to pregnant or breastfeeding women because of their side effects. We briefly reviewed the issue of treatment of HCV infection in pregnant/breastfeeding women focusing on the effects of the new direct-acting antivirals on fertility, pregnancy and lactation in animal studies and on the potential risk for humans based on the pharmacokinetic properties of each drug. Currently, all new therapy regimens are contraindicated in this setting because of lack of sufficient safety information and adequate measures of contraception are still routinely recommended for female patients of childbearing potential. PMID:27134703

  7. Antiviral Role of IFITM Proteins in African Swine Fever Virus Infection

    PubMed Central

    Martínez-Romero, Carles; Barrado-Gil, Lucía; Galindo, Inmaculada; García-Sastre, Adolfo; Alonso, Covadonga

    2016-01-01

    The interferon-induced transmembrane (IFITM) protein family is a group of antiviral restriction factors that impair flexibility and inhibit membrane fusion at the plasma or the endosomal membrane, restricting viral progression at entry. While IFITMs are widely known to inhibit several single-stranded RNA viruses, there are limited reports available regarding their effect in double-stranded DNA viruses. In this work, we have analyzed a possible antiviral function of IFITMs against a double stranded DNA virus, the African swine fever virus (ASFV). Infection with cell-adapted ASFV isolate Ba71V is IFN sensitive and it induces IFITMs expression. Interestingly, high levels of IFITMs caused a collapse of the endosomal pathway to the perinuclear area. Given that ASFV entry is strongly dependent on endocytosis, we investigated whether IFITM expression could impair viral infection. Expression of IFITM1, 2 and 3 reduced virus infectivity in Vero cells, with IFITM2 and IFITM3 having an impact on viral entry/uncoating. The role of IFITM2 in the inhibition of ASFV in Vero cells could be related to impaired endocytosis-mediated viral entry and alterations in the cholesterol efflux, suggesting that IFITM2 is acting at the late endosome, preventing the decapsidation stage of ASFV. PMID:27116236

  8. Developing new antiviral agents for influenza treatment: what does the future hold?

    PubMed

    Hayden, Frederick

    2009-01-01

    Antiviral agents for the treatment of influenza are urgently needed to circumvent the limitations of current drugs in several critical areas: high frequencies of resistance to M2 inhibitors among currently circulating strains and variable frequencies of resistance to oseltamivir among A(H1N1) strains, limited efficacy of treatment and treatment-emergent antiviral resistance in cases of avian influenza A(H5N1) illness in humans, and lack of parenteral agents for seriously ill patients. Two neuraminidase inhibitors (NAIs), zanamivir and peramivir, have undergone or are undergoing clinical trials for use by intravenous or intramuscular administration, and one long-acting NAI, designated CS-8958, is under study for use by inhalation. Advances in understanding the mechanisms involved in influenza virus replication have revealed a number of potential targets that might be exploited in the development of new agents. Among these agents are T-705, a polymerase inhibitor, and DAS181, an attachment inhibitor. Combination therapy with currently available agents is supported by data from animal models but has received limited clinical study to date.

  9. 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

  10. 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

  11. Antiviral drugs for viruses other than human immunodeficiency virus.

    PubMed

    Razonable, Raymund R

    2011-10-01

    Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti-human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M(2) inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects.

  12. Antiviral Drugs for Viruses Other Than Human Immunodeficiency Virus

    PubMed Central

    Razonable, Raymund R.

    2011-01-01

    Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M2 protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti–human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M2 inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects. PMID

  13. Optimizing antiviral agents for hepatitis B management in malignant lymphomas

    PubMed Central

    Ozoya, Oluwatobi O.; Chavez, Julio; Sokol, Lubomir

    2017-01-01

    The global scale of hepatitis B infection is well known but its impact is still being understood. Missed hepatitis B infection impacts lymphoma therapy especially increased risk of hepatitis B virus (HBV) reactivation and poor treatment outcomes. The presence of undiagnosed chronic hepatitis also undermines chronic HBV screening methods that are based on a positive HBsAg alone. The goal of this review is to evaluate the literature for optimizing antiviral therapy for lymphoma patients with HBV infection or at risk of HBV reactivation. Relevant articles for this review were identified by searching PubMed, Embase, Ovid Medline, and Scopus using the following terms, alone and in combination: “chronic hepatitis B”, “occult hepatitis B”, ”special groups”, “malignant lymphoma”, “non-Hodgkin’s lymphoma”, “Hodgkin’s lymphoma”, “immunocompromised host”, “immunosuppressive agents”, “antiviral”, “HBV reactivation”. The period of the search was restricted to a 15-year period to limit the search to optimizing antiviral agents for HBV infection in malignant lymphomas [2001–2016]. Several clinical practice guidelines recommend nucleos(t)ide analogues-entecavir, tenofovir and lamivudine among others. These agents are best initiated along with or prior to immunosuppressive therapy. Additional methods recommended for optimizing antiviral therapy include laboratory modalities such as HBV genotyping, timed measurements of HBsAg and HBV DNA levels to measure and predict antiviral treatment response. In conclusion, optimizing antiviral agents for these patients require consideration of geographic prevalence of HBV, cost of antiviral therapy or testing, screening modality, hepatitis experts, type of immunosuppressive therapy and planned duration of therapy. PMID:28251118

  14. Interferon: signal molecules involved in its antiviral effect.

    PubMed

    Constantinescu, S N; Cernescu, C; Baltă, F; Popescu, L M

    1989-01-01

    A major problem concerning interferon (IFN)-cell interaction is the second messenger system that transduces the IFN signal. We discuss the evidences existing in literature and our arguments which suggest that the antiviral effect of IFNs alpha and beta are mediated by a membrane mechanism including a phospholipase C dependent hydrolysis of phosphoinositides. The resulting two second messengers: diacylglycerol and inositol triphosphate and subsequent, separate but interacting, signal pathways: activation of protein kinase C and ionic events are tested in respect with the antiviral effect of IFN.

  15. 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.

  16. RNA interference-mediated intrinsic antiviral immunity in invertebrates.

    PubMed

    Nayak, Arabinda; Tassetto, Michel; Kunitomi, Mark; Andino, Raul

    2013-01-01

    In invertebrates such as insects and nematodes, RNA interference (RNAi) provides RNA-based protection against viruses. This form of immunity restricts viral replication and dissemination from infected cells and viruses, in turn, have evolved evasion mechanisms or RNAi suppressors to counteract host defenses. Recent advances indicate that, in addition to RNAi, other related small RNA pathways contribute to antiviral functions in invertebrates. This has led to a deeper understanding of fundamental aspects of small RNA-based antiviral immunity in invertebrates and its contribution to viral spread and pathogenesis.

  17. Enhanced antiviral activity of acyclovir loaded into nanoparticles.

    PubMed

    Cavalli, Roberta; Donalisio, Manuela; Bisazza, Agnese; Civra, Andrea; Ranucci, Elisabetta; Ferruti, Paolo; Lembo, David

    2012-01-01

    The activity of antivirals can be enhanced by their incorporation in nanoparticulate delivery systems. Peculiar polymeric nanoparticles, based on a β-cyclodextrin-poly(4-acryloylmorpholine) monoconjugate (β-CD-PACM), are proposed as acyclovir carriers. The experimental procedure necessary to obtain the acyclovir-loaded nanoparticles using the solvent displacement preparation method will be described in this chapter. Fluorescent labeled nanoparticles are prepared using the same method for cellular trafficking studies. The biocompatibility assays necessary to obtain safe nanoparticles are reported. Section 4 of this chapter describes the assessment of the antiviral activity of the acyclovir-loaded nanoparticles.

  18. Novel antiviral fucoidan from sporophyll of Undaria pinnatifida (Mekabu).

    PubMed

    Lee, Jung-Bum; Hayashi, Kyoko; Hashimoto, Minoru; Nakano, Takahisa; Hayashi, Toshimitsu

    2004-09-01

    Structural characterization and antiviral activities of fucoidan from sporophyll of Undaria pinnatifida (Mekabu) was examined. The fucoidan was composed of fucose and galactose with an approximately ratio of 1.0:1.1. Degree of substitution of sulfate was 0.72 and its apparent molecular weight was 9,000. Methylation analyses showed that fucoidan had various sugar linkages, and revealed that the fucoidan might have complicated structure. This fucoidan showed potent antiviral activities against herpes simplex virus type 1 (HSV-1), HSV-2, and human cytomegalovirus.

  19. Quasispecies, error catastrophe, and the antiviral activity of ribavirin.

    PubMed

    Graci, Jason D; Cameron, Craig E

    2002-07-05

    Ribavirin is the first synthetic, broad-spectrum antiviral nucleoside. Despite its more than 30 year history, the mechanism of action of this compound remains unclear and somewhat controversial. Recent data suggest the possibility that the activity of ribavirin against RNA viruses is a reflection of incorporation of ribavirin into the viral genome. Because ribavirin incorporation is not specific, this event leads to lethal mutagenesis of the virus population. The data supporting this new proposal for the mechanism of action of ribavirin are reviewed herein. In addition, we discuss briefly the challenges that remain for development of lethal mutagenesis as an effective antiviral strategy.

  20. Multifunctional roles of leader protein of foot-and-mouth disease viruses in suppressing host antiviral responses.

    PubMed

    Liu, Yingqi; Zhu, Zixiang; Zhang, Miaotao; Zheng, Haixue

    2015-10-28

    Foot-and-mouth disease virus (FMDV) leader protein (L(pro)) is a papain-like proteinase, which plays an important role in FMDV pathogenesis. L(pro) exists as two forms, Lab and Lb, due to translation being initiated from two different start codons separated by 84 nucleotides. L(pro) self-cleaves from the nascent viral polyprotein precursor as the first mature viral protein. In addition to its role as a viral proteinase, L(pro) also has the ability to antagonize host antiviral effects. To promote FMDV replication, L(pro) can suppress host antiviral responses by three different mechanisms: (1) cleavage of eukaryotic translation initiation factor 4 γ (eIF4G) to shut off host protein synthesis; (2) inhibition of host innate immune responses through restriction of interferon-α/β production; and (3) L(pro) can also act as a deubiquitinase and catalyze deubiquitination of innate immune signaling molecules. In the light of recent functional and biochemical findings regarding L(pro), this review introduces the basic properties of L(pro) and the mechanisms by which it antagonizes host antiviral responses.

  1. IL-27 improves migrational and antiviral potential of CB dendritic cells.

    PubMed

    Birkholz, Julia; Doganci, Aysefa; Darstein, Claudia; Gehring, Stephan; Zepp, Fred; Meyer, Claudius U

    2014-06-01

    Interleukin (IL)-27 is known to be increased considerably in cord blood (CB) dendritic cells (DCs) after TLR ligation. Previously, we demonstrated that also basal IL-27 levels are higher in CB DCs. Here, we examined effects of IL-27 on monocyte derived dendritic cells (moDCs) to approach its particular role in the specialized immune system of the human neonate. Exogenous IL-27 promotes IL-27 transcription in CB and adult blood (AB) moDCs. IL-27 acts on CB moDCs primarily by significantly augmenting IL-27 protein, secondarily by increasing transcription of CXCL10 among other chemokines, chemokine receptor CCR1, interferon stimulated genes, transcription factor IRF8 and genes involved in antigen presentation. Furthermore, CB moDCs respond to IL-27 with augmented IL-8 and Tumor necrosis factor (TNF)-α. The results suggest that IL-27 enhances migrational and antiviral properties of CB dendritic cells.

  2. Antiviral nucleoside analogs phosphorylation by nucleoside diphosphate kinase.

    PubMed

    Gallois-Montbrun, S; Veron, M; Deville-Bonne, D

    2004-05-01

    The reaction of NDP kinase was studied in vitro with several antiviral derivatives, using kinetic steady state and presteady state analysis. The enzyme is highly efficient with natural nucleotides but most of the analogs are slow substrates. The catalytic efficiency, also related to the affinity of the analog, is mainly dependent on the presence of a 3'-OH group on the ribose moiety.

  3. De novo computer-aided design of novel antiviral agents.

    PubMed

    Massarotti, Alberto; Coluccia, Antonio; Sorba, Giovanni; Silvestri, Romano; Brancale, Andrea

    2012-01-01

    Computer-aided drug design techniques have become an integral part of the drug discovery process. In particular, de novo methodologies can be useful to identify putative ligands for a specific target relying only on the structural information of the target itself. Here we discuss the basic de novo approaches available and their application in antiviral drug design.:

  4. Liposomal Systems as Nanocarriers for the Antiviral Agent Ivermectin

    PubMed Central

    Croci, Romina; Bottaro, Elisabetta; Chan, Kitti Wing Ki; Watanabe, Satoru; Pezzullo, Margherita; Mastrangelo, Eloise; Nastruzzi, Claudio

    2016-01-01

    RNA virus infections can lead to the onset of severe diseases such as fever with haemorrhage, multiorgan failure, and mortality. The emergence and reemergence of RNA viruses continue to pose a significant public health threat worldwide with particular attention to the increasing incidence of flaviviruses, among others Dengue, West Nile Virus, and Yellow Fever viruses. Development of new and potent antivirals is thus urgently needed. Ivermectin, an already known antihelminthic drug, has shown potent effects in vitro on Flavivirus helicase, with EC50 values in the subnanomolar range for Yellow Fever and submicromolar EC50 for Dengue Fever, Japanese encephalitis, and tick-borne encephalitis viruses. However ivermectin is hampered in its application by pharmacokinetic problems (little solubility and high cytotoxicity). To overcome such problems we engineered different compositions of liposomes as ivermectin carriers characterizing and testing them on several cell lines for cytotoxicity. The engineered liposomes were less cytotoxic than ivermectin alone and they showed a significant increase of the antiviral activity in all the Dengue stains tested (1, 2, and S221). In the current study ivermectin is confirmed to be an effective potential antiviral and liposomes, as drug carriers, are shown to modulate the drug activity. All together the results represent a promising starting point for future improvement of ivermectin as antiviral and its delivery. PMID:27242902

  5. Novel drug delivery approaches on antiviral and antiretroviral agents

    PubMed Central

    Sharma, Pooja; Chawla, Anuj; Arora, Sandeep; Pawar, Pravin

    2012-01-01

    Viruses have the property to replicate very fast in host cell. It can attack any part of host cell. Therefore, the clinical efficacy of antiviral drugs and its bioavailability is more important concern taken into account to treat viral infections. The oral and parenteral routes of drug administration have several shortcomings, however, which could lead to the search for formulating better delivery systems. Now, a day's novel drug delivery systems (NDDS) proved to be a better approach to enhance the effectiveness of the antivirals and improve the patient compliance and decrease the adverse effect. The NDDS have reduced the dosing frequency and shorten the duration of treatment, thus, which could lead the treatment more cost-effective. The development of NDDS for antiviral and antiretroviral therapy aims to deliver the drug devoid of toxicity, with high compatibility and biodegradability, targeting the drug to specific sites for viral infection and in some instances it also avoid the first pass metabolism effect. This article aims to discuss the usefulness of novel delivery approaches of antiviral agents such as niosomes, microspheres, microemulsions, nanoparticles that are used in the treatment of various Herpes viruses and in human immunodeficiency virus (HIV) infections. PMID:23057001

  6. Mitochondrial DNA Stress Primes the Antiviral Innate Immune Response

    PubMed Central

    West, A. Phillip; Khoury-Hanold, William; Staron, Matthew; Tal, Michal C.; Pineda, Cristiana M.; Lang, Sabine M.; Bestwick, Megan; Duguay, Brett A.; Raimundo, Nuno; MacDuff, Donna A.; Kaech, Susan M.; Smiley, James R.; Means, Robert E.; Iwasaki, Akiko; Shadel, Gerald S.

    2014-01-01

    Mitochondrial DNA (mtDNA) is normally present at thousands of copies per cell and is packaged into several hundred higher-order structures termed nucleoids1. The abundant mtDNA-binding protein, transcription factor A mitochondrial (TFAM), regulates nucleoid architecture, abundance, and segregation2. Complete mtDNA depletion profoundly impairs oxidative phosphorylation (OXPHOS), triggering calcium-dependent stress signaling and adaptive metabolic responses3. However, the cellular responses to mtDNA instability, a physiologically relevant stress observed in many human diseases and aging, remain ill-defined4. Here we show that moderate mtDNA stress elicited by TFAM deficiency engages cytosolic antiviral signaling to enhance the expression of a subset of interferon-stimulated genes (ISG). Mechanistically, we have found that aberrant mtDNA packaging promotes escape of mtDNA into the cytosol, where it engages the DNA sensor cGAS and promotes STING-IRF3-dependent signaling to elevate ISG expression, potentiate type I interferon responses, and confer broad viral resistance. Furthermore, we demonstrate that herpesviruses induce mtDNA stress, which potentiates antiviral signaling and type I interferon responses during infection. Our results further demonstrate that mitochondria are central participants in innate immunity, identify mtDNA stress as a cell-intrinsic trigger of antiviral signaling, and suggest that cellular monitoring of mtDNA homeostasis cooperates with canonical virus sensing mechanisms to fully license antiviral innate immunity. PMID:25642965

  7. 75 FR 16151 - Antiviral Drugs Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-31

    ... HUMAN SERVICES Food and Drug Administration Antiviral Drugs Advisory Committee; Notice of Meeting AGENCY: Food and Drug Administration, HHS. ACTION: Notice. This notice announces a forthcoming meeting of a public advisory committee of the Food and Drug Administration (FDA). The meeting will be open to...

  8. 76 FR 62418 - Antiviral Drugs Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... HUMAN SERVICES Food and Drug Administration Antiviral Drugs Advisory Committee; Notice of Meeting AGENCY: Food and Drug Administration, HHS. ACTION: Notice. This notice announces a forthcoming meeting of a public advisory committee of the Food and Drug Administration (FDA). The meeting will be open to...

  9. 78 FR 57166 - Antiviral Drugs Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... HUMAN SERVICES Food and Drug Administration Antiviral Drugs Advisory Committee; Notice of Meeting AGENCY: Food and Drug Administration, HHS. ACTION: Notice. This notice announces a forthcoming meeting of a public advisory committee of the Food and Drug Administration (FDA). The meeting will be open to...

  10. Adenovirus infection reverses the antiviral state induced by human interferon.

    PubMed

    Feduchi, E; Carrasco, L

    1987-04-06

    HeLa cells treated with human lymphoblastoid interferon do not synthesize poliovirus proteins. The antiviral state against poliovirus is reversed if cells are previously infected with adenovirus type 5. A late gene product seems to be involved in this reversion, since no effect is observed at early stages of infection or in the presence of aphidicolin.

  11. Platinum(II)-Acyclovir Complexes: Synthesis, Antiviral and Antitumour Activity

    PubMed Central

    Coluccia, M.; Boccarelli, A.; Cermelli, C.; Portolani, M.; Natile, G.

    1995-01-01

    A platinum(II) complex with the antiviral drug acyclovir was synthesized and its antiviral and anticancer properties were investigated in comparison to those of acyclovir and cisplatin. The platinum-acyclovir complex maintained the antiviral activity of the parent drug acyclovir, though showing a minor efficacy on a molar basis (ID50  =   7.85 and 1.02 μΜ for platinum-acyclovir and cisplatin, respectively). As anticancer agent, the platinum-acyclovir complex was markedly less potent than cisplatin on a mole-equivalent basis, but it was as effective as cisplatin when equitoxic dosages were administered in vivo to P388 leukaemia-bearing mice (%T/C = 209 and 211 for platinum-acyclovir and cisplatin, respectively). The platinum-acyclovir complex was also active against a cisplatin-resistant subline of the P388 leukaemia (%T/C = 140), thus suggesting a different mechanism of action. The DNA interaction properties (sequence specificity and interstrand cross-linking ability) of platinum-acyclovir were also investigated in comparison to those of cisplatin and [Pt(dien)Cl]+, an antitumour-inactive platinum-triamine compound. The results of this study point to a potential new drug endowed, at the same time, with antiviral and anticancer activity and characterized by DNA interaction properties different from those of cisplatin. PMID:18472776

  12. Synergistic antiviral activity of gemcitabine and ribavirin against enteroviruses.

    PubMed

    Kang, Hyunju; Kim, Chonsaeng; Kim, Dong-eun; Song, Jae-Hyoung; Choi, Miri; Choi, Kwangman; Kang, Mingu; Lee, Kyungjin; Kim, Hae Soo; Shin, Jin Soo; Kim, Janghwan; Han, Sang-Bae; Lee, Mi-Young; Lee, Su Ui; Lee, Chong-Kyo; Kim, Meehyein; Ko, Hyun-Jeong; van Kuppeveld, Frank J M; Cho, Sungchan

    2015-12-01

    Enteroviruses are major causative agents of various human diseases, and some of them are currently considered to be an enormous threat to public health. However, no effective therapy is currently available for the treatment of these infections. We identified gemcitabine, a nucleoside-analog drug used for cancer treatment, from a screen of bioactive chemicals as a novel inhibitor of coxsackievirus B3 (CVB3) and enterovirus 71 (EV71). Gemcitabine potently inhibited the proliferation of CVB3 and EV71, as well as the replication of CVB3 and EV71 replicons, in cells with a low micromolar IC50 (1-5 μM). Its strong inhibitory effect was also observed in cells infected with human rhinoviruses, demonstrating broad-spectrum antiviral effects on enteroviruses. Mechanistically, an extensive analysis excluded the involvement of 2C, 3A, IRES-dependent translation, and also that of polyprotein processing in the antiviral effects of gemcitabine. Importantly, gemcitabine in combination with ribavirin, an antiviral drug currently being used against a few RNA viruses, exhibited a synergistic antiviral effect on the replication of CVB3 and EV71 replicons. Consequently, our results clearly demonstrate a new indication for gemcitabine as an effective broad-spectrum inhibitor of enteroviruses and strongly suggest a new therapeutic strategy using gemcitabine alone or in combination with ribavirin for the treatment of various diseases associated with enterovirus infection.

  13. Synthesis and antiviral evaluation of bisnoradamantane sulfites and related compounds.

    PubMed

    Valverde, Elena; Torres, Eva; Guardiola, Salvador; Naesens, Lieve; Vázquez, Santiago

    2011-03-01

    The reaction of a series of 1,2-diols with thionyl chloride led to bisnoradamantane sulfites in very good yields. The reaction has also been applied to related polycyclic scaffolds. The compounds have been tested for antiviral activity but none of them showed to be active. Several attempts to generate and trap SO from these polycyclic sulfites have been unsuccessful.

  14. Modeling rotavirus infection and antiviral therapy using primary intestinal organoids.

    PubMed

    Yin, Yuebang; Bijvelds, Marcel; Dang, Wen; Xu, Lei; van der Eijk, Annemiek A; Knipping, Karen; Tuysuz, Nesrin; Dekkers, Johanna F; Wang, Yijin; de Jonge, Jeroen; Sprengers, Dave; van der Laan, Luc J W; Beekman, Jeffrey M; Ten Berge, Derk; Metselaar, Herold J; de Jonge, Hugo; Koopmans, Marion P G; Peppelenbosch, Maikel P; Pan, Qiuwei

    2015-11-01

    Despite the introduction of oral vaccines, rotavirus still kills over 450,000 children under five years of age annually. The absence of specific treatment prompts research aiming at further understanding of pathogenesis and the development of effective antiviral therapy, which in turn requires advanced experimental models. Given the intrinsic limitations of the classical rotavirus models using immortalized cell lines infected with laboratory-adapted strains in two dimensional cultures, our study aimed to model infection and antiviral therapy of both experimental and patient-derived rotavirus strains using three dimensional cultures of primary intestinal organoids. Intestinal epithelial organoids were successfully cultured from mouse or human gut tissues. These organoids recapitulate essential features of the in vivo tissue architecture, and are susceptible to rotavirus. Human organoids are more permissive to rotavirus infection, displaying an over 10,000-fold increase in genomic RNA following 24h of viral replication. Furthermore, infected organoids are capable of producing infectious rotavirus particles. Treatment of interferon-alpha or ribavirin inhibited viral replication in organoids of both species. Importantly, human organoids efficiently support the infection of patient-derived rotavirus strains and can be potentially harnessed for personalized evaluation of the efficacy of antiviral medications. Therefore, organoids provide a robust model system for studying rotavirus-host interactions and assessing antiviral medications.

  15. 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.

  16. Lipid flippases promote antiviral silencing and the biogenesis of viral and host siRNAs in Arabidopsis.

    PubMed

    Guo, Zhongxin; Lu, Jinfeng; Wang, Xianbing; Zhan, Binhui; Li, Wanxiang; Ding, Shou-Wei

    2017-02-07

    Dicer-mediated processing of virus-specific dsRNA into short interfering RNAs (siRNAs) in plants and animals initiates a specific antiviral defense by RNA interference (RNAi). In this study, we developed a forward genetic screen for the identification of host factors required for antiviral RNAi in Arabidopsis thaliana Using whole-genome sequencing and a computational pipeline, we identified aminophospholipid transporting ATPase 2 (ALA2) and the related ALA1 in the type IV subfamily of P-type ATPases as key components of antiviral RNAi. ALA1 and ALA2 are flippases, which are transmembrane lipid transporter proteins that transport phospholipids across cellular membranes. We found that the ala1/ala2 single- and double-mutant plants exhibited enhanced disease susceptibility to cucumber mosaic virus when the virus-encoded function to suppress RNAi was disrupted. Notably, the antiviral activity of both ALA1 and ALA2 was abolished by a single amino acid substitution known to inactivate the flippase activity. Genetic analysis revealed that ALA1 and ALA2 acted to enhance the amplification of the viral siRNAs by RNA-dependent RNA polymerase (RdRP) 1 (RDR1) and RDR6 and of the endogenous virus-activated siRNAs by RDR1. RNA virus replication by plant viral RdRPs occurs inside vesicle-like membrane invaginations induced by the recruitment of the viral RdRP and host factors to subcellular membrane microdomains enriched with specific phospholipids. Our results suggest that the phospholipid transporter activity of ALA1/ALA2 may be necessary for the formation of similar invaginations for the synthesis of dsRNA precursors of highly abundant viral and host siRNAs by the cellular RdRPs.

  17. 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

  18. Antiviral therapy for chronic hepatitis B: a review.

    PubMed

    Hanazaki, Kazuhiro

    2004-03-01

    Chronic hepatitis B virus (HBV) infection is a well-recognized risk factor for the development of hepatocellular carcinoma (HCC), which is becoming a more prevalent clinical problem, especially in HBV-endemic areas. It is estimated that 1.25 million people in the United States and more than 300 million people worldwide are chronically infected with HBV. Despite the introduction of universal vaccination against hepatitis B in over 100 countries, persistent HBV infection is still a serious problem worldwide, causing an estimated annual death rate of one million. It may take several decades until the effect of vaccination will be translated into reduced transmission and morbidity. Meanwhile, patients with persistent HBV infection require better antiviral therapeutic modalities than are currently available. It is well accepted that antiviral therapy for chronic hepatitis B is effective to improve prognosis of patients with HBV by preventing development of hepatitis state and HCC. The therapeutic endpoints for hepatitis B treatment are: 1) sustained suppression of HBV replication, as indicated by HBsAg and HBeAg loss, 2) decrease of serum HBV DNA of an undetectable level by a non-PCR method, 3) remission of disease, as shown by normalization of ALT, 4) improvement in liver histology, and 5) reduction of the acute exacerbation, cirrhosis, and HCC. In the present, the antiviral treatment of hepatitis B consists of either interferon alpha or oral lamivudine alone or in combination with existing therapy. Each major antiviral drug of interferon alpha and lamivudine has pros and cons, and effect of combination therapy of both drugs is also still limited. More powerful and safe new antiviral therapies are required to achieve final goal of these therapeutic endpoints. Management of chronic hepatitis B requires significant knowledge of approved pharmacotherapeutic agents and their limitations. Therapeutic options for managing hepatitis infection after liver transplantation (LT

  19. Antiviral Effect of Methylated Flavonol Isorhamnetin against Influenza

    PubMed Central

    Dayem, Ahmed Abdal; Choi, Hye Yeon; Kim, Young Bong; Cho, Ssang-Goo

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3′, and 4′ positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3′-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1). However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method) in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B). Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70–80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR) of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids. PMID:25806943

  20. Antiviral effect of methylated flavonol isorhamnetin against influenza.

    PubMed

    Abdal Dayem, Ahmed; Choi, Hye Yeon; Kim, Young Bong; Cho, Ssang-Goo

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3'-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1). However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method) in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B). Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70-80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR) of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids.

  1. 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

  2. Acting Atoms.

    ERIC Educational Resources Information Center

    Farin, Susan Archie

    1997-01-01

    Describes a fun game in which students act as electrons, protons, and neutrons. This activity is designed to help students develop a concrete understanding of the abstract concept of atomic structure. (DKM)

  3. Cost-Effectiveness of Hepatitis C Treatment for People Who Inject Drugs and the Impact of the Type of Epidemic; Extrapolating from Amsterdam, the Netherlands

    PubMed Central

    van Santen, Daniëla K.; de Vos, Anneke S.; Matser, Amy; Willemse, Sophie B.; Lindenburg, Karen; Kretzschmar, Mirjam E. E.; Prins, Maria; de Wit, G. Ardine

    2016-01-01

    Background People who inject drugs (PWID) are disproportionally affected by the hepatitis C virus (HCV) infection. The efficacy of HCV treatment has significantly improved in recent years with the introduction of direct-acting antivirals (DAAs). However, DAAs are more costly than pegylated-interferon and ribavirin (PegIFN/RBV). We aimed to assess the cost-effectiveness of four HCV treatment strategies among PWID and treatment scale-up. Methods An individual-based model was used describing HIV and HCV transmission and disease progression among PWID. We considered two epidemiological situations. A declining epidemic, based on the situation in Amsterdam, the Netherlands, and a stable HCV epidemic, as observed in other settings. Data on HCV incidence, prevalence, treatment setting and uptake were derived from observed data among PWID in Amsterdam. We assessed the incremental cost-effectiveness ratio (ICER, costs in €/quality-adjusted life year (QALY)) of four treatment strategies: 1) PegIFN/RBV; 2) sofosbuvir/RBV for genotype 2–3 and dual DAA for genotype 1–4; 3) Dual DAA for all genotypes; 4) Dual DAA with 3x treatment uptake. Results In both types of epidemic, dual DAA therapy was most cost-effective strategy. In the declining epidemic, dual DAA yielded an ICER of 344 €/QALY while in the stable epidemic dual DAA led to cost-savings. Scaling-up treatment was also highly cost-effective. Our results were robust over a range of sensitivity analyses. Conclusion HCV treatment with DAA-containing regimens is a highly cost-effective intervention among PWID. Based on the economic and population benefits of scaling-up treatment, stronger efforts are needed to achieve higher uptake rates among PWID. PMID:27711200

  4. Epimedium koreanum Nakai Displays Broad Spectrum of Antiviral Activity in Vitro and in Vivo by Inducing Cellular Antiviral State

    PubMed Central

    Cho, Won-Kyung; Weeratunga, Prasanna; Lee, Byeong-Hoon; Park, Jun-Seol; Kim, Chul-Joong; Ma, Jin Yeul; Lee, Jong-Soo

    2015-01-01

    Epimedium koreanum Nakai has been extensively used in traditional Korean and Chinese medicine to treat a variety of diseases. Despite the plant’s known immune modulatory potential and chemical make-up, scientific information on its antiviral properties and mode of action have not been completely investigated. In this study, the broad antiviral spectrum and mode of action of an aqueous extract from Epimedium koreanum Nakai was evaluated in vitro, and moreover, the protective effect against divergent influenza A subtypes was determined in BALB/c mice. An effective dose of Epimedium koreanum Nakaimarkedly reduced the replication of Influenza A Virus (PR8), Vesicular Stomatitis Virus (VSV), Herpes Simplex Virus (HSV) and Newcastle Disease Virus (NDV) in RAW264.7 and HEK293T cells. Mechanically, we found that an aqueous extract from Epimedium koreanum Nakai induced the secretion of type I IFN and pro-inflammatory cytokines and the subsequent stimulation of the antiviral state in cells. Among various components present in the extract, quercetin was confirmed to have striking antiviral properties. The oral administration of Epimedium koreanum Nakai exhibited preventive effects on BALB/c mice against lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3 and H9N2). Therefore, an extract of Epimedium koreanum Nakai and its components play roles as immunomodulators in the innate immune response, and may be potential candidates for prophylactic or therapeutic treatments against diverse viruses in animal and humans. PMID:25609307

  5. Advanced DAA Methods for Shock Response Analysis

    DTIC Science & Technology

    1992-07-01

    57 7.7 MODIFIED CESARO SUMMATION FOR IMPROVED CONVERGENCE .............................. 58 vi TABLE OF CONTENTS (Continued) Section Page 7.8...infinite series through the first N+l terms, the Nth Cesaro sum, aN, of that series is the arithmetic mean of the first N+ 1 partial sums SN , i.e., N N = Y... Cesaro summation employs weights that decrease linearly from one for the first term to zero for xn+ I and beyond. Clearly, the filter characteristic

  6. The Interferon Type I/III Response to Respiratory Syncytial Virus Infection in Airway Epithelial Cells Can Be Attenuated or Amplified by Antiviral Treatment

    PubMed Central

    Jordan, R.; Mawhorter, M. E.; Noton, S. L.; Powers, J. G.; Fearns, R.; Cihlar, T.; Perron, M.

    2015-01-01

    ABSTRACT Human respiratory syncytial virus (RSV) is a single-stranded RNA virus that causes acute, and occasionally fatal, lower respiratory illness in young infants, the elderly, and immunocompromised patients. Therapeutic interventions able to cut short viral replication and quickly return the airways to normal function are needed. An understanding of antiviral activities and their effects on host defense mechanisms is important for the design of safe and effective therapy. We targeted functionally and temporally distinct steps within the viral life cycle using small-molecule RSV inhibitors and studied their antiviral activities and their effects on innate interferon responses of airway epithelial cells in vitro. Antivirals acting upstream of RSV polymerase activity (i.e., compounds targeting the fusion protein or the nucleoprotein) reduced viral load immediately postinfection and partially attenuated interferon responses. In contrast, antivirals directed to the RSV polymerase demonstrated activity throughout the viral replication cycle and specifically modulated the RIG-I/mitochondrial antiviral signaling protein (MAVS)/TBK1/IRF3/interferon-stimulated gene (ISG) axis, causing either an upregulation or a downregulation of interferon responses, depending on the mechanism of polymerase inhibition. Notably, polymerase inhibition leading to the accumulation of abortive RNA products correlated with the amplification of interferon-stimulated genes to up to 10 times above normal infection levels. Understanding how antiviral activities and their modulation of innate immunity may affect recovery from RSV infection will help guide the development of safe and effective therapies. IMPORTANCE RSV circulates seasonally, causing acute lower respiratory disease. Therapeutic interventions with efficacy throughout the viral replication cycle, rapid viral clearance, and prevention of potentially harmful inflammatory responses are desirable. Compounds targeting the RSV polymerase

  7. Antiviral therapy for human immunodeficiency virus infections.

    PubMed Central

    De Clercq, E

    1995-01-01

    Depending on the stage of their intervention with the viral replicative cycle, human immunodeficiency virus inhibitors could be divided into the following groups: (i) adsorption inhibitors (i.e., CD4 constructs, polysulfates, polysulfonates, polycarboxylates, and polyoxometalates), (ii) fusion inhibitors (i.e., plant lectins, succinylated or aconitylated albumins, and betulinic acid derivatives), (iii) uncoating inhibitors (i.e., bicyclams), (iv) reverse transcription inhibitors acting either competitively with the substrate binding site (i.e., dideoxynucleoside analogs and acyclic nucleoside phosphonates) or allosterically with a nonsubstrate binding site (i.e., non-nucleoside reverse transcriptase inhibitors), (v) integration inhibitors, (vi) DNA replication inhibitors, (vii) transcription inhibitors (i.e., antisense oligodeoxynucleotides and Tat antagonists), (viii) translation inhibitors (i.e., antisense oligodeoxynucleotides and ribozymes), (ix) maturation inhibitors (i.e., protease inhibitors, myristoylation inhibitors, and glycosylation inhibitors), and finally, (x) budding (assembly/release) inhibitors. Current knowledge, including the therapeutic potential, of these various inhibitors is discussed. In view of their potential clinical the utility, the problem of virus-drug resistance and possible strategies to circumvent this problem are also addressed. PMID:7542558

  8. [Self-reported experience in patients treated with Hepatitis C direct acting antivirals].

    PubMed

    Cañamares Orbis, Irene; Saez de la Fuente, Javier; Escobar Rodriguez, Ismael; Esteban Alba, Concepción; Such Díaz, Ana; Escobar Rodríguez, Ismael

    2016-11-01

    Introducción y objetivo: Conocer y analizar la experiencia autorreferida del tratamiento de los pacientes VHC que iniciaron tratamiento con agentes antivirales directos (AAD), a tiempo real, de forma proactiva e integrada en el proceso asistencial de atención farmacéutica. Material y métodos: Estudio observacional y transversal desarrollado entre abril (inicio del Plan Estratégico Nacional) y diciembre de 2015 en la Consulta Externa del Servicio de Farmacia. Se utilizó como herramienta un cuestionario prospectivo cumplimentado por los pacientes donde se recogieron variables relacionadas con la calidad de vida vinculadas con la salud (CVRS), adherencia, efectos adversos (EA), satisfacción con el tratamiento, y valoración y utilidad del programa formativo implementado por el Servicio de Farmacia. Se realizó un análisis descriptivo de todas las variables incluidas en el estudio y se analizó la influencia de las diferentes variables en el grado de adherencia y CVRS. El análisis de las diferencias entre los dos grupos se realizó mediante el test de chi cuadrado y el cálculo de las OR con un modelo de regresión logística simple. Se utilizó el programa SPSS® versión 20, y se estableció una significación estadística para valores de p < 0,05. Resultados: Se recogieron155 encuestas de las 226 enviadas, tasa de respuesta del 68,6%.En referencia a la CVRS (valoración del estado físico y emocional), un 38,7% de los pacientes refieren que su estado físico y emocional es mucho mejor desde el inicio del tratamiento. La presencia de EA y una peor información global de su enfermedad se asoció con un peor estado físico y emocional (p < 0,05). La adherencia reportada fue del 84,5% y el tratamiento fue valorado como muy bueno o bueno por el 87% de los pacientes. Un 52,9% de los pacientes no tuvieron efectos adversos relacionados con la medicación y el proceso formativo realizado por el farmacéutico especialista en la primera consulta fue valorado por el 96,7% de los pacientes como muy bueno o bueno. Conclusiones: La experiencia autorreferida obtenida a través de un contacto directo y permanente con los pacientes permite obtener información sobre aspectos importantes del tratamiento. Creemos que estas herramientas deben incorporarse a los procedimientos de atención farmacéutica como una forma de mantener la continuidad. Además, inducen al paciente a una autoevaluación de diversos aspectos de su propio tratamiento, que pueden ayudar a conseguir una mayor implicación en el mismo y contribuir a conseguir el máximo resultado en salud posible de la farmacoterapia.

  9. Microbiota-Dependent Priming of Antiviral Intestinal Immunity in Drosophila.

    PubMed

    Sansone, Christine L; Cohen, Jonathan; Yasunaga, Ari; Xu, Jie; Osborn, Greg; Subramanian, Harry; Gold, Beth; Buchon, Nicolas; Cherry, Sara

    2015-11-11

    Enteric pathogens must overcome intestinal defenses to establish infection. In Drosophila, the ERK signaling pathway inhibits enteric virus infection. The intestinal microflora also impacts immunity but its role in enteric viral infection is unknown. Here we show that two signals are required to activate antiviral ERK signaling in the intestinal epithelium. One signal depends on recognition of peptidoglycan from the microbiota, particularly from the commensal Acetobacter pomorum, which primes the NF-kB-dependent induction of a secreted factor, Pvf2. However, the microbiota is not sufficient to induce this pathway; a second virus-initiated signaling event involving release of transcriptional paused genes mediated by the kinase Cdk9 is also required for Pvf2 production. Pvf2 stimulates antiviral immunity by binding to the receptor tyrosine kinase PVR, which is necessary and sufficient for intestinal ERK responses. These findings demonstrate that sensing of specific commensals primes inflammatory signaling required for epithelial responses that restrict enteric viral infections.

  10. Direct versus sequential immunoglobulin switch in allergy and antiviral responses.

    PubMed

    Svirshchevskaya, E; Fattakhova, G; Khlgatian, S; Chudakov, D; Kashirina, E; Ryazantsev, D; Kotsareva, O; Zavriev, S

    2016-09-01

    Allergy is characterized by IgE production to innocuous antigens. The question whether the switch to IgE synthesis occurs via direct or sequential pathways is still unresolved. The aim of this work was to analyze the distribution of immunoglobulins (Ig) to house dust mite D. farinae and A. alternata fungus in allergic children with primarily established diagnosis and compare it to Epstein-Barr antiviral (EBV) response in the same patients. In allergy patients the only significant difference was found in allergen specific IgE, likely mediated by a direct isotype switch, while antiviral response was dominated by EBV specific IgG and low level of concordant IgA and IgG4 production consistent with a minor sequential Ig switches. Taken collectively, we concluded that sequential isotype switch is likely to be a much rarer event than a direct one.

  11. Toll-like receptors in antiviral innate immunity

    PubMed Central

    Lester, Sandra N.; Li, Kui

    2014-01-01

    Toll-like receptors (TLRs) are fundamental sensor molecules of the host innate immune system, which detect conserved molecular signatures of a wide range of microbial pathogens and initiate innate immune responses via distinct signaling pathways. Various TLRs are implicated in the early interplay of host cells with invading viruses, which regulates viral replication and/or host responses, ultimately impacting on viral pathogenesis. To survive the host innate defense mechanisms, many viruses have developed strategies to evade or counteract signaling through the TLR pathways, creating an advantageous environment for their propagation. Here we review the current knowledge of the roles TLRs play in antiviral innate immune responses, discuss examples of TLR-mediated viral recognition, and describe strategies used by viruses to antagonize the host antiviral innate immune responses. PMID:24316048

  12. Antiviral Activity of Resveratrol against Human and Animal Viruses

    PubMed Central

    Abba, Yusuf; Hassim, Hasliza; Hamzah, Hazilawati; Noordin, Mohamed Mustapha

    2015-01-01

    Resveratrol is a potent polyphenolic compound that is being extensively studied in the amelioration of viral infections both in vitro and in vivo. Its antioxidant effect is mainly elicited through inhibition of important gene pathways like the NF-κβ pathway, while its antiviral effects are associated with inhibitions of viral replication, protein synthesis, gene expression, and nucleic acid synthesis. Although the beneficial roles of resveratrol in several viral diseases have been well documented, a few adverse effects have been reported as well. This review highlights the antiviral mechanisms of resveratrol in human and animal viral infections and how some of these effects are associated with the antioxidant properties of the compound. PMID:26693226

  13. Screening of Australian medicinal plants for antiviral activity.

    PubMed

    Semple, S J; Reynolds, G D; O'Leary, M C; Flower, R L

    1998-03-01

    Extracts of 40 different plant species used in the traditional medicine of the Australian Aboriginal people have been investigated for antiviral activity. The extracts have been tested for activity against one DNA virus, human cytomegalovirus (HCMV) and two RNA viruses, Ross River virus (RRV) and poliovirus type 1, at non-cytotoxic concentrations. The most active extracts were the aerial parts of Pterocaulon sphacelatum (Asteraceae) and roots of Dianella longifolia var. grandis (Liliaceae), which inhibited poliovirus at concentrations of 52 and 250 microg/ml, respectively. The extracts of Euphorbia australis (Euphorbiaceae) and Scaevola spinescens (Goodeniaceae) were the most active against HCMV. Extracts of Eremophila latrobei subsp. glabra (Myoporaceae) and Pittosporum phylliraeoides var. microcarpa (Pittosporaceae) exhibited antiviral activity against RRV.

  14. 5th Antiviral Drug Discovery and Development Summit.

    PubMed

    Blair, Wade; Perros, Manos

    2004-08-01

    The 5th Antiviral Drug Discovery and Development Summit provided an up-to-date snapshot of the ongoing developments in the area. The topics covered ranged from updates on recently launched drugs (Kaletra), Fuzeon) and new investigational inhibitors (T-1249, Reverset, UK-427857, L-870810, PA-457, remofovir, VX-950), to the discovery of new antiviral targets and advances in technologies that may provide the substrate for the next generation of therapeutics. It is apparent from the range of presentations that much of today's efforts are focused on developing new classes of HIV inhibitors (gp41, integrase), while there is also considerable progress in hepatitis C, where a number of inhibitors have or should reach proof-of-concept studies in the coming months. Here we provide the highlights of this meeting, with particular emphasis on the new developments in HIV and hepatitis C virus.

  15. Peptide-Induced Antiviral Protection by Cytotoxic T Cells

    NASA Astrophysics Data System (ADS)

    Schulz, Manfred; Zinkernagel, Rolf M.; Hengartner, Hans

    1991-02-01

    A specific antiviral cytotoxic immune response in vivo could be induced by the subcutaneous injection of the T-cell epitope of the lymphocytic choriomeningitis virus (LCMV) nucleoprotein as an unmodified free synthetic peptide (Arg-Pro-Gln-Ala-Ser-Gly-Val-Tyr-Met-Gly-Asn-Leu-Thr-Ala-Gln) emulsified in incomplete Freund's adjuvant. This immunization rendered mice into a LCMV-specific protective state as shown by the inhibition of LCMV replication in spleens of such mice. The protection level of these mice correlated with the ability to respond to the peptide challenge by CD8^+ virus-specific cytotoxic T cells. This is a direct demonstration that peptide vaccines can be antivirally protective in vivo, thus encouraging further search for appropriate mixtures of stable peptides that may be used as T-cell vaccines.

  16. Preventing and treating secondary bacterial infections with antiviral agents

    PubMed Central

    McCullers, Jonathan A.

    2016-01-01

    Summary Bacterial super-infections contribute to the significant morbidity and mortality associated with influenza and other respiratory virus infections. There are robust animal model data but only limited clinical information on the effectiveness of licensed antiviral agents for the treatment of bacterial complications of influenza. The association of secondary bacterial pathogens with fatal pneumonia during the recent H1N1 influenza pandemic highlights the need for new development in this area. Basic and clinical research into viral-bacterial interactions over the last decade has revealed several mechanisms that underlie this synergism. By applying these insights to antiviral drug development, the potential exists to improve outcomes by means other than direct inhibition of the virus. PMID:21447860

  17. Novel drugs targeting Toll-like receptors for antiviral therapy

    PubMed Central

    Patel, Mira C; Shirey, Kari Ann; Pletneva, Lioubov M; Boukhvalova, Marina S; Garzino-Demo, Alfredo; Vogel, Stefanie N; Blanco, Jorge CG

    2014-01-01

    Toll-like receptors (TLRs) are sentinel receptors of the host innate immune system that recognize conserved ‘pathogen-associated molecular patterns’ of invading microbes, including viruses. The activation of TLRs establishes antiviral innate immune responses and coordinates the development of long-lasting adaptive immunity in order to control viral pathogenesis. However, microbe-induced damage to host tissues may release ‘danger-associated molecular patterns’ that also activate TLRs, leading to an overexuberant inflammatory response and, ultimately, to tissue damage. Thus, TLRs have proven to be promising targets as therapeutics for the treatment of viral infections that result in inflammatory damage or as adjuvants in order to enhance the efficacy of vaccines. Here, we explore recent advances in TLR biology with a focus on novel drugs that target TLRs (agonists and antagonists) for antiviral therapy. PMID:25620999

  18. Mx proteins: antiviral proteins by chance or by necessity?

    PubMed

    Arnheiter, H; Meier, E

    1990-10-01

    The interferon-inducible Mx1 protein is responsible for inborn resistance of mice to influenza. It is now recognized that this protein is a member of a family of interferon-inducible, putative GTP-binding proteins found in many organisms. Thus, these proteins, called the Mx proteins, are found in species that are naturally infected with influenza virus, and also in species that are not. Some Mx proteins display a broader antiviral profile than the one observed for Mx1 in mice. Others, however, may not be antiviral. Two recently discovered GTP-binding proteins, Vps1p in yeast and dynamin in rat, are also related to Mx1. These proteins are synthesized constitutively and serve basic cellular functions.

  19. Senataxin suppresses the antiviral transcriptional response and controls viral biogenesis.

    PubMed

    Miller, Matthew S; Rialdi, Alexander; Ho, Jessica Sook Yuin; Tilove, Micah; Martinez-Gil, Luis; Moshkina, Natasha P; Peralta, Zuleyma; Noel, Justine; Melegari, Camilla; Maestre, Ana M; Mitsopoulos, Panagiotis; Madrenas, Joaquín; Heinz, Sven; Benner, Chris; Young, John A T; Feagins, Alicia R; Basler, Christopher F; Fernandez-Sesma, Ana; Becherel, Olivier J; Lavin, Martin F; van Bakel, Harm; Marazzi, Ivan

    2015-05-01

    The human helicase senataxin (SETX) has been linked to the neurodegenerative diseases amyotrophic lateral sclerosis (ALS4) and ataxia with oculomotor apraxia (AOA2). Here we identified a role for SETX in controlling the antiviral response. Cells that had undergone depletion of SETX and SETX-deficient cells derived from patients with AOA2 had higher expression of antiviral mediators in response to infection than did wild-type cells. Mechanistically, we propose a model whereby SETX attenuates the activity of RNA polymerase II (RNAPII) at genes stimulated after a virus is sensed and thus controls the magnitude of the host response to pathogens and the biogenesis of various RNA viruses (e.g., influenza A virus and West Nile virus). Our data indicate a potentially causal link among inborn errors in SETX, susceptibility to infection and the development of neurologic disorders.

  20. 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

  1. Protein modifications during antiviral heat bioprocessing and subsequent storage.

    PubMed

    Smales, C M; Pepper, D S; James, D C

    2001-01-01

    Antiviral heat treatment is routinely used in the bioprocessing of therapeutic proteins as a means of reducing viral load. However, in protein formulations containing sucrose this form of bioprocessing can lead to protein modifications. Using a model protein, hen egg white lysozyme, we investigated the effects of antiviral heat treatments in the presence of sucrose on protein integrity during subsequent long-term protein storage. Although heat treatment alone resulted in protein modification, subsequent medium- to long-term storage of both lyophilized and liquid samples at room temperature or above led to further protein modifications. The majority of these modifications were due to the formation of glycation and advanced glycation end products via the reaction of reducing sugars and their autoxidation products (derived from hydrolyzed sucrose) with function groups on the protein surface. These findings have implications for the improvement of therapeutic protein bioprocessing to ensure protein product quality.

  2. Balancing Act

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2007-01-01

    For some administrators and planners, designing and building education facilities may sometimes seem like a circus act--trying to project a persona of competence and confidence while juggling dozens of issues. Meanwhile, the audience--students, staff members and taxpayers--watch and wait with anticipation in hopes of getting what they paid for and…

  3. Phospholipid scramblase 1 potentiates the antiviral activity of interferon.

    PubMed

    Dong, Beihua; Zhou, Quansheng; Zhao, Ji; Zhou, Aimin; Harty, Ronald N; Bose, Santanu; Banerjee, Amiya; Slee, Roger; Guenther, Jeanna; Williams, Bryan R G; Wiedmer, Therese; Sims, Peter J; Silverman, Robert H

    2004-09-01

    Phospholipid scramblase 1 (PLSCR1) is an interferon (IFN)- and growth factor-inducible, calcium-binding protein that either inserts into the plasma membrane or binds DNA in the nucleus depending on its state of palmyitoylation. In certain hematopoietic cells, PLSCR1 is required for normal maturation and terminal differentiation from progenitor cells as regulated by select growth factors, where it promotes recruitment and activation of Src kinases. PLSCR1 is a substrate of Src (and Abl) kinases, and transcription of the PLSCR1 gene is regulated by the same growth factor receptor pathways in which PLSCR1 potentiates afferent signaling. The marked transcriptional upregulation of PLSCR1 by IFNs led us to explore whether PLSCR1 plays an analogous role in cellular responses to IFN, with specific focus on antiviral activities. Accordingly, human cells in which PLSCR1 expression was decreased with short interfering RNA were rendered relatively insensitive to the antiviral activity of IFNs, resulting in higher titers of vesicular stomatitis virus (VSV) and encephalomyocarditis virus. Similarly, VSV replicated to higher titers in mouse PLSCR1(-/-) embryonic fibroblasts than in identical cells transduced to express PLSCR1. PLSCR1 inhibited accumulation of primary VSV transcripts, similar to the effects of IFN against VSV. The antiviral effect of PLSCR1 correlated with increased expression of a subset of IFN-stimulated genes (ISGs), including ISG15, ISG54, p56, and guanylate binding proteins. Our results suggest that PLSCR1, which is itself an ISG-encoded protein, provides a mechanism for amplifying and enhancing the IFN response through increased expression of a select subset of potent antiviral genes.

  4. Antiviral Strategies for Emerging Influenza Viruses in Remote Communities

    PubMed Central

    Laskowski, Marek; Greer, Amy L.; Moghadas, Seyed M.

    2014-01-01

    Background Due to the lack of timely access to resources for critical care, strategic use of antiviral drugs is crucial for mitigating the impact of novel influenza viruses with pandemic potential in remote and isolated communities. We sought to evaluate the effect of antiviral treatment and prophylaxis of close contacts in a Canadian remote northern community. Methods We used an agent-based, discrete-time simulation model for disease spread in a remote community, which was developed as an in-silico population using population census data. Relative and cumulative age-specific attack rates, and the total number of infections in simulated model scenarios were obtained. Results We found that early initiation of antiviral treatment is more critical for lowering attack rates in a remote setting with a low population-average age compared to an urban population. Our results show that a significant reduction in the relative, age-specific attack rates due to increasing treatment coverage does not necessarily translate to a significant reduction in the overall arrack rate. When treatment coverage varies from low to moderate, targeted prophylaxis has a very limited impact in reducing attack rates and should be offered at a low level (below 10%) to avoid excessive waste of drugs. Conclusions In contrast to previous work, for conservative treatment coverages, our results do not provide any convincing evidence for the implementation of targeted prophylaxis. The findings suggest that public health strategies in remote communities should focus on the wider availability (higher coverage) and timely distribution of antiviral drugs for treatment of clinically ill individuals. PMID:24586937

  5. Antiviral and antimicrobial assessment of some selected flavonoids.

    PubMed

    Ozçelik, Berrin; Orhan, Ilkay; Toker, Gülnur

    2006-01-01

    In the current study, the results of antibacterial, antifungal, and antiviral activity tests of four flavonoid derivatives, scandenone (1), tiliroside (2), quercetin-3,7-O-alpha-L-dirhamnoside (3), and kaempferol-3,7-O-alpha-L-dirhamnoside (4), are presented. Antibacterial and antifungal activities of these compounds were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis, as well as the fungus Candida albicans by a micro-dilution method. On the other hand, both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza-3 (PI-3) were employed for antiviral assessment of the compounds using Madin-Darby bovine kidney and Vero cell lines. According to our data, all of the compounds tested were found to be quite active against S. aureus and E. faecalis with MIC values of 0.5 microg/ml, followed by E. coli (2 microg/ml), K. pneumoniae (4 microg/ml), A. baumannii (8 micro/g/ml), and B. subtilis (8 microg/ml), while they inhibited C. albicans at 1 microg/ml as potent as ketoconazole. However, only compound 3 displayed an antiviral effect towards PI-3 in the range of 8-32 microg/ml of inhibitory concentration for cytopathogenic effect (CPE).

  6. Human enterovirus 71 protein interaction network prompts antiviral drug repositioning

    PubMed Central

    Han, Lu; Li, Kang; Jin, Chaozhi; Wang, Jian; Li, Qingjun; Zhang, Qiling; Cheng, Qiyue; Yang, Jing; Bo, Xiaochen; Wang, Shengqi

    2017-01-01

    As a predominant cause of human hand, foot, and mouth disease, enterovirus 71 (EV71) infection may lead to serious diseases and result in severe consequences that threaten public health and cause widespread panic. Although the systematic identification of physical interactions between viral proteins and host proteins provides initial information for the recognition of the cellular mechanism involved in viral infection and the development of new therapies, EV71-host protein interactions have not been explored. Here, we identified interactions between EV71 proteins and host cellular proteins and confirmed the functional relationships of EV71-interacting proteins (EIPs) with virus proliferation and infection by integrating a human protein interaction network and by functional annotation. We found that most EIPs had known interactions with other viruses. We also predicted ATP6V0C as a broad-spectrum essential host factor and validated its essentiality for EV71 infection in vitro. EIPs and their interacting proteins were more likely to be targets of anti-inflammatory and neurological drugs, indicating their potential to serve as host-oriented antiviral targets. Thus, we used a connectivity map to find drugs that inhibited EIP expression. We predicted tanespimycin as a candidate and demonstrated its antiviral efficiency in vitro. These findings provide the first systematic identification of EV71-host protein interactions, an analysis of EIP protein characteristics and a demonstration of their value in developing host-oriented antiviral therapies. PMID:28220872

  7. Improving nucleoside diphosphate kinase for antiviral nucleotide analogs activation.

    PubMed

    Gallois-Montbrun, Sarah; Schneider, Benoit; Chen, Yuxing; Giacomoni-Fernandes, Veronique; Mulard, Laurence; Morera, Solange; Janin, Joel; Deville-Bonne, Dominique; Veron, Michel

    2002-10-18

    Antiviral nucleoside analog therapies rely on their incorporation by viral DNA polymerases/reverse transcriptase leading to chain termination. The analogs (3'-deoxy-3'-azidothymidine (AZT), 2',3'-didehydro-2',3'-dideoxythymidine (d4T), and other dideoxynucleosides) are sequentially converted into triphosphate by cellular kinases of the nucleoside salvage pathway and are often poor substrates of these enzymes. Nucleoside diphosphate (NDP) kinase phosphorylates the diphosphate derivatives of the analogs with an efficiency some 10(4) lower than for its natural substrates. Kinetic and structural studies of Dictyostelium and human NDP kinases show that the sugar 3'-OH, absent from all antiviral analogs, is required for catalysis. To improve the catalytic efficiency of NDP kinase on the analogs, we engineered several mutants with a protein OH group replacing the sugar 3'-OH. The substitution of Asn-115 in Ser and Leu-55 in His results in an NDP kinase mutant with an enhanced ability to phosphorylate antiviral derivatives. Transfection of the mutant enzyme in Escherichia coli results in an increased sensitivity to AZT. An x-ray structure at 2.15-A resolution of the Dictyostelium enzyme bearing the serine substitution in complex with the R(p)-alpha-borano-triphosphate derivative of AZT shows that the enhanced activity reflects an improved geometry of binding and a favorable interaction of the 3'-azido group with the engineered serine.

  8. Broad specificity of human phosphoglycerate kinase for antiviral nucleoside analogs.

    PubMed

    Gallois-Montbrun, Sarah; Faraj, Abdesslem; Seclaman, Edward; Sommadossi, Jean-Pierre; Deville-Bonne, Dominique; Véron, Michel

    2004-11-01

    Nucleoside analogs used in antiviral therapies need to be phosphorylated to their tri-phospho counterparts in order to be active on their cellular target. Human phosphoglycerate kinase (hPGK) was recently reported to participate in the last step of phosphorylation of cytidine L-nucleotide derivatives [Krishnan PGE, Lam W, Dutschman GE, Grill SP, Cheng YC. Novel role of 3-phosphoglycerate kinase, a glycolytic enzyme, in the activation of L-nucleoside analogs, a new class of anticancer and antiviral agents. J Biol Chem 2003;278:36726-32]. In the present work, we extended the enzymatic study of human PGK specificity to purine and pyrimidine nucleotide derivatives in both D- and L-configuration. Human PGK demonstrated catalytic efficiencies in the 10(4)-10(5)M(-1)s(-1) range for purine ribo-, deoxyribo- and dideoxyribonucleotide derivatives, either in D- or L-configuration. In contrast, it was poorly active with natural pyrimidine D-nucleotides (less than 10(3)M(-1)s(-1)). Pyrimidine L-enantiomers, which are promising therapeutic analogs against B hepatitis, were 2-25 times better substrates than their D-counterparts. The broad specificity of substrate of human PGK suggests that this enzyme may be involved in the cellular activation of several antiviral nucleoside analogs including dideoxyinosine, acyclovir, L-2'-deoxycytosine and L-2'-deoxythymidine.

  9. 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.

  10. Design, synthesis and antiviral activity of novel quinazolinones.

    PubMed

    Wang, Ziwen; Wang, Mingxiao; Yao, Xue; Li, Yue; Tan, Juan; Wang, Lizhong; Qiao, Wentao; Geng, Yunqi; Liu, Yuxiu; Wang, Qingmin

    2012-07-01

    HIV-1 integrase (IN) is a validated therapeutic target for antiviral drug design. However, the emergence of viral strains resistant to clinically studied IN inhibitors demands the discovery of novel inhibitors that are structurally as well as mechanistically different. Herein, a series of quinazolinones were designed and synthesized as novel HIV-1 inhibitors. The new synthetic route provides a practical method for the preparation of 5-hydroxy quinazolinones. Primary bioassay results indicated that most of the quinazolinones possess anti-HIV activity, especially for compound 11b with 77.5% inhibition rate at 10 μM emerged as a new active lead. Most of the synthesized compounds were also found to exhibit good anti-TMV activity, of which compo und 9a showed similar in vivo anti-TMV activity to commercial plant virucide Ribavirin. This work provides a new and efficient approach to evolve novel multi-functional antiviral agents by rational integration and optimization of previously reported antiviral agents.

  11. Insect antiviral innate immunity: pathways, effectors, and connections.

    PubMed

    Kingsolver, Megan B; Huang, Zhijing; Hardy, Richard W

    2013-12-13

    Insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the small, interfering RNA pathway that responds through the detection of virus-derived double-stranded RNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, and Jak-STAT and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review, we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses.

  12. Insect antiviral innate immunity: pathways, effectors, and connections

    PubMed Central

    Kingsolver, Megan B.; Huang, Zhijing; Hardy, Richard W.

    2014-01-01

    Insects are infected by a wide array of viruses some of which are insect-restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the siRNA pathway that responds through the detection of virus-derived dsRNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, Jak-STAT, and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses. PMID:24120681

  13. Antiviral response dictated by choreographed cascade of transcription factors

    PubMed Central

    Zaslavsky, Elena; Hershberg, Uri; Seto, Jeremy; Pham, Alissa M.; Marquez, Susanna; Duke, Jamie L.; Wetmur, James G.; tenOever, Benjamin R.; Sealfon, Stuart C.; Kleinstein, Steven H.

    2010-01-01

    The dendritic cell (DC) is a master regulator of immune responses. Pathogenic viruses subvert normal immune function in DCs through the expression of immune antagonists. Understanding how these antagonists interact with the host immune system requires knowledge of the underlying genetic regulatory network that operates during an uninhibited antiviral response. In order to isolate and identify this network, we studied DCs infected with Newcastle Disease Virus (NDV), which is able to stimulate innate immunity and DC maturation through activation of RIG-I signaling, but lacks the ability to evade the human interferon response. To analyze this experimental model, we developed a new approach integrating genome-wide expression kinetics and time-dependent promoter analysis. We found that the genetic program underlying the antiviral cell-state transition during the first 18-hours post-infection could be explained by a single convergent regulatory network. Gene expression changes were driven by a step-wise multi-factor cascading control mechanism, where the specific transcription factors controlling expression changed over time. Within this network, most individual genes are regulated by multiple factors, indicating robustness against virus-encoded immune evasion genes. In addition to effectively recapitulating current biological knowledge, we predicted, and validated experimentally, antiviral roles for several novel transcription factors. More generally, our results show how a genetic program can be temporally controlled through a single regulatory network to achieve the large-scale genetic reprogramming characteristic of cell state transitions. PMID:20164420

  14. Immunoenhancing properties and antiviral activity of 7-deazaguanosine in mice.

    PubMed Central

    Smee, D F; Alaghamandan, H A; Gilbert, J; Burger, R A; Jin, A; Sharma, B S; Ramasamy, K; Revankar, G R; Cottam, H B; Jolley, W B

    1991-01-01

    The nucleotide analog 7-deazaguanosine has not previously been reported to possess biological (antiviral or antitumor) properties in cell culture or in vivo. Up to 10(5) U of interferon per ml was detected in mouse sera 1 to 4 h following oral (200-mg/kg of body weight) and intraperitoneal (50-mg/kg) doses of the compound. 7-Deazaguanosine also caused significant activation of natural killer and phagocytic cells but did not augment T- and B-cell blastogenesis. Intraperitoneal treatments of 50, 100, and 200 mg/kg/day administered 24 and 18 h before virus inoculation were highly protective in mice inoculated with lethal doses of Semliki Forest or San Angelo viruses. Less but still significant survivor increases were evident in treated mice infected with banzi or encephalomyocarditis viruses. In most cases, the degree of antiviral activity was similar to that exhibited by the biological response modifier 7-thia-8-oxoguanosine. 7-Thia-8-oxoguanosine was more potent than 7-deazaguanosine against encephalomyocarditis virus in mice, however. Oral efficacy was achieved with 7-deazaguanosine treatments of greater than or equal to 100 mg/kg against all virus infections, whereas 7-thia-8-oxoguanosine is reported to be devoid of oral activity in rodents. Thus, 7-deazaguanosine represents the first reported orally active nucleoside biological response modifier exhibiting broad-spectrum antiviral activity against particular types of RNA viruses. PMID:1707603

  15. Human enterovirus 71 protein interaction network prompts antiviral drug repositioning.

    PubMed

    Han, Lu; Li, Kang; Jin, Chaozhi; Wang, Jian; Li, Qingjun; Zhang, Qiling; Cheng, Qiyue; Yang, Jing; Bo, Xiaochen; Wang, Shengqi

    2017-02-21

    As a predominant cause of human hand, foot, and mouth disease, enterovirus 71 (EV71) infection may lead to serious diseases and result in severe consequences that threaten public health and cause widespread panic. Although the systematic identification of physical interactions between viral proteins and host proteins provides initial information for the recognition of the cellular mechanism involved in viral infection and the development of new therapies, EV71-host protein interactions have not been explored. Here, we identified interactions between EV71 proteins and host cellular proteins and confirmed the functional relationships of EV71-interacting proteins (EIPs) with virus proliferation and infection by integrating a human protein interaction network and by functional annotation. We found that most EIPs had known interactions with other viruses. We also predicted ATP6V0C as a broad-spectrum essential host factor and validated its essentiality for EV71 infection in vitro. EIPs and their interacting proteins were more likely to be targets of anti-inflammatory and neurological drugs, indicating their potential to serve as host-oriented antiviral targets. Thus, we used a connectivity map to find drugs that inhibited EIP expression. We predicted tanespimycin as a candidate and demonstrated its antiviral efficiency in vitro. These findings provide the first systematic identification of EV71-host protein interactions, an analysis of EIP protein characteristics and a demonstration of their value in developing host-oriented antiviral therapies.

  16. [Griseochelin methyl ester, a new polyether derivative with antiviral activity].

    PubMed

    Tonew, E; Tonew, M; Graefe, U; Zöpel, P

    1988-10-01

    The methylester of griseochelin (1) is a new chemically-made antiviral derivate of the antibiotic griseochelin isolated from fermentations of Streptomyces griseus. It belongs to the polyether group and possesses antiviral activity against enveloped RNA and DNA viruses cultivated in chicken embryo cells (CEC), namely influenzavirus A/WSN, vesicularstomatitis virus (Indiana), vaccinia virus (Lister) and herpes simplex hominis virus type 1 (Kupka). The methylester of griseochelin failed to show virucidal effects on extracellular influenza vacciniavirus particles or to influence virus adsorption and penetration processes. The antibiotic in concentrations of 125-15 micrograms/ml inhibited the virus-induced cytopathic effect of the above mentioned viruses and caused over 90 per cent plaque reduction. Addition of 1 during a one-step growth cycle of influenzavirus A at 4 and 6 h p.i. resulted in complete suppression of virus multiplication at the control niveau of the virus yield accumulated to the same time point. A partial reversibility of the antiviral action against influenzavirus A could be achieved. Coxsackie A9 virus growth in human fibroblast cells was not affected by the inhibitor. Electron-optical observations showed a failure of the formation of the viral capside proteins of HSV type 1 at the second halftime of the replication cycle in CEC-infected and 1-treated cultures.

  17. Antiviral and antiproliferative effects of canine interferon-λ1.

    PubMed

    Ichihashi, Tomonori; Asano, Atsushi; Usui, Tatsufumi; Takeuchi, Takashi; Watanabe, Yasuko; Yamano, Yoshiaki

    2013-11-15

    Interferon (IFN)-λs, members of the type III IFN group, were recently identified in several vertebrates. Although IFN-λs have the potential to be utilized as antiviral and antitumor agents in veterinary medicine, the biological properties of IFN-λs have not yet been studied in companion animals. In this study, we analyzed the expression of canine IFN-λs and their receptors, produced a recombinant canine IFN-λ1 protein, and investigated its antiviral and antiproliferative activities using a canine kidney epithelial cell line, MDCK cells. MDCK cells were found to express type III IFN molecules, IFN-λ1 and IFN-λ3, and the receptors, IFNλR1 and IL10R2. IFN-λ1 was induced faster than IFN-λ3 by stimulation with poly (I:C). His-tagged IFN-λ1 protein expressed in Escherichia coli inhibited cytolytic plaque formation by influenza A virus infection, and induced the expression of interferon-stimulated genes, Mx1 and OAS1, in MDCK cells. In addition, recombinant IFN-λ1 inhibited the proliferation of MDCK cells slightly. These effects were observed in a dose-dependent manner. These results indicate that canine IFN-λ1 has antiviral effect, and suggest the potential applicability of canine IFN-λ1 as a therapeutic agent.

  18. Favipiravir elicits antiviral mutagenesis during virus replication in vivo

    PubMed Central

    Arias, Armando; Thorne, Lucy; Goodfellow, Ian

    2014-01-01

    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. DOI: http://dx.doi.org/10.7554/eLife.03679.001 PMID:25333492

  19. Polar profile of antiviral peptides from AVPpred Database.

    PubMed

    Polanco, Carlos; Samaniego, José Lino; Castañón-González, Jorge Alberto; Buhse, Thomas

    2014-11-01

    Diseases of viral origin in humans are among the most serious threats to health and the global economy. As recent history has shown the virus has a high pandemic potential, among other reasons, due to its ability to spread by air, hence the identification, investigation, containment, and treatment of viral diseases should be considered of paramount importance. In this sense, the bioinformatics research has focused on finding fast and efficient algorithms that can identify highly toxic antiviral peptides and to serve as a first filter, so that trials in the laboratory are substantially reduced. The work presented here contributes to this effort through the use of an algorithm already published by this team, called polarity index method, which identifies with high efficiency antiviral peptides from the exhaustive analysis of the polar profile, using the linear sequence of the peptide. The test carried out included all peptides in APD2 Database and 60 antiviral peptides identified by Kumar and co-workers (Nucleic Acids Res 40:W199-204, 2012), to build its AVPpred algorithm. The validity of the method was focused on its discriminating capacity so we included the 15 sub-classifications of both Databases.

  20. Antiviral agents and HIV prevention: controversies, conflicts, and consensus

    PubMed Central

    Cohen, Myron S.; Muessig, Kathryn E.; Smith, M. Kumi; Powers, Kimberly A.; Kashuba, Angela D.M.

    2013-01-01

    Antiviral agents can be used to prevent HIV transmission before exposure as preexpo-sure prophylaxis (PrEP), after exposure as postexposure prophylaxis, and as treatment of infected people for secondary prevention. Considerable research has shed new light on antiviral agents for PrEP and for prevention of secondary HIV transmission. While promising results have emerged from several PrEP trials, the challenges of poor adherence among HIV-negative clients and possible increase in sexual risk behaviors remain a concern. In addition, a broader pipeline of antiviral agents for PrEP that focuses on genital tract pharmacology and safety and resistance issues must be developed. Antiretroviral drugs have also been used to prevent HIV transmission from HIV-infected patients to their HIV-discordant sexual partners. The HIV Prevention Trials Network 052 trial demonstrated nearly complete prevention of HIV transmission by early treatment of infection, but the generalizability of the results to other risk groups – including intravenous drug users and MSM – has not been determined. Most importantly, the best strategy for use of antiretroviral agents to reduce the spread of HIV at either the individual level or the population level has not been developed, and remains the ultimate goal of this area of investigation. PMID:22507927

  1. Sofosbuvir treatment and hepatitis C virus infection

    PubMed Central

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

    2016-01-01

    Hepatitis C virus (HCV) infection is a serious problem worldwide. The use of interferon-based therapy has made HCV eradication challenging. The recent appearance of direct-acting antiviral agents (DAAs) has changed HCV therapy. Combining the use of DAAs with peginterferon and ribavirin has improved treatment efficacy. Furthermore, the combination of different orally administered DAAs has enabled interferon-free therapy with much higher efficacy and safety. In particular, sofosbuvir, a nucleotide-based NS5B inhibitor, prevents HCV RNA synthesis by acting as a “chain terminator”. Treatment with sofosbuvir has attained an extremely high rate of sustained virologic response. The current review summarizes the efficacy and safety of sofosbuvir therapy. PMID:26839641

  2. Identification of a New Benzimidazole Derivative as an Antiviral against Hepatitis C Virus

    PubMed Central

    Vausselin, Thibaut; Séron, Karin; Lavie, Muriel; Mesalam, Ahmed Atef; Lemasson, Matthieu; Belouzard, Sandrine; Fénéant, Lucie; Danneels, Adeline; Rouillé, Yves; Cocquerel, Laurence; Foquet, Lander; Rosenberg, Arielle R.; Wychowski, Czeslaw; Meuleman, Philip

    2016-01-01

    ABSTRACT Aminoquinolines and piperazines, linked or not, have been used successfully to treat malaria, and some molecules of this family also exhibit antiviral properties. Here we tested several derivatives of 4-aminoquinolines and piperazines for their activity against hepatitis C virus (HCV). We screened 11 molecules from three different families of compounds, and we identified anti-HCV activity in cell culture for six of them. Of these, we selected a compound (B5) that is currently ending clinical phase I evaluation for neurodegenerative diseases. In hepatoma cells, B5 inhibited HCV infection in a pangenotypic and dose-dependent manner, and its antiviral activity was confirmed in primary hepatocytes. B5 also inhibited infection by pseudoparticles expressing HCV envelope glycoproteins E1 and E2, and we demonstrated that it affects a postattachment stage of the entry step. Virus with resistance to B5 was selected by sequential passage in the presence of the drug, and reverse genetics experiments indicated that resistance was conferred mainly by a single mutation in the putative fusion peptide of E1 envelope glycoprotein (F291I). Furthermore, analyses of the effects of other closely related compounds on the B5-resistant mutant suggest that B5 shares a mode of action with other 4-aminoquinoline-based molecules. Finally, mice with humanized liver that were treated with B5 showed a delay in the kinetics of the viral infection. In conclusion, B5 is a novel interesting anti-HCV molecule that could be used to decipher the early steps of the HCV life cycle. IMPORTANCE In the last 4 years, HCV therapy has been profoundly improved with the approval of direct-acting antivirals in clinical practice. Nevertheless, the high costs of these drugs limit access to therapy in most countries. The present study reports the identification and characterization of a compound (B5) that inhibits HCV propagation in cell culture and is currently ending clinical phase I evaluation for

  3. Discovery of a Broad-Spectrum Antiviral Compound That Inhibits Pyrimidine Biosynthesis and Establishes a Type 1 Interferon-Independent Antiviral State

    PubMed Central

    Adcock, Robert S.; Schroeder, Chad E.; Chu, Yong-Kyu; Sotsky, Julie B.; Cramer, Daniel E.; Chilton, Paula M.; Song, Chisu; Anantpadma, Manu; Davey, Robert A.; Prodhan, Aminul I.; Yin, Xinmin; Zhang, Xiang

    2016-01-01

    Viral emergence and reemergence underscore the importance of developing efficacious, broad-spectrum antivirals. Here, we report the discovery of tetrahydrobenzothiazole-based compound 1, a novel, broad-spectrum antiviral lead that was optimized from a hit compound derived from a cytopathic effect (CPE)-based antiviral screen using Venezuelan equine encephalitis virus. Compound 1 showed antiviral activity against a broad range of RNA viruses, including alphaviruses, flaviviruses, influenza virus, and ebolavirus. Mechanism-of-action studies with metabolomics and molecular approaches revealed that the compound inhibits host pyrimidine synthesis and establishes an antiviral state by inducing a variety of interferon-stimulated genes (ISGs). Notably, the induction of the ISGs by compound 1 was independent of the production of type 1 interferons. The antiviral activity of compound 1 was cell type dependent with a robust effect observed in human cell lines and no observed antiviral effect in mouse cell lines. Herein, we disclose tetrahydrobenzothiazole compound 1 as a novel lead for the development of a broad-spectrum, antiviral therapeutic and as a molecular probe to study the mechanism of the induction of ISGs that are independent of type 1 interferons. PMID:27185801

  4. Discovery of a Broad-Spectrum Antiviral Compound That Inhibits Pyrimidine Biosynthesis and Establishes a Type 1 Interferon-Independent Antiviral State.

    PubMed

    Chung, Dong-Hoon; Golden, Jennifer E; Adcock, Robert S; Schroeder, Chad E; Chu, Yong-Kyu; Sotsky, Julie B; Cramer, Daniel E; Chilton, Paula M; Song, Chisu; Anantpadma, Manu; Davey, Robert A; Prodhan, Aminul I; Yin, Xinmin; Zhang, Xiang

    2016-08-01

    Viral emergence and reemergence underscore the importance of developing efficacious, broad-spectrum antivirals. Here, we report the discovery of tetrahydrobenzothiazole-based compound 1, a novel, broad-spectrum antiviral lead that was optimized from a hit compound derived from a cytopathic effect (CPE)-based antiviral screen using Venezuelan equine encephalitis virus. Compound 1 showed antiviral activity against a broad range of RNA viruses, including alphaviruses, flaviviruses, influenza virus, and ebolavirus. Mechanism-of-action studies with metabolomics and molecular approaches revealed that the compound inhibits host pyrimidine synthesis and establishes an antiviral state by inducing a variety of interferon-stimulated genes (ISGs). Notably, the induction of the ISGs by compound 1 was independent of the production of type 1 interferons. The antiviral activity of compound 1 was cell type dependent with a robust effect observed in human cell lines and no observed antiviral effect in mouse cell lines. Herein, we disclose tetrahydrobenzothiazole compound 1 as a novel lead for the development of a broad-spectrum, antiviral therapeutic and as a molecular probe to study the mechanism of the induction of ISGs that are independent of type 1 interferons.

  5. Current treatment of chronic hepatitis C in China: Dilemma and potential problems.

    PubMed

    Han, Qun-Ying; Liu, Zheng-Wen

    2016-05-21

    Major advances have been made in the treatment of chronic hepatitis C virus (HCV) infection with the advent of direct-acting antiviral agents (DAAs). China has the most cases of HCV infection worldwide, but none of the DAAs has been approved in mainland China so far, and interferon (IFN)-α-based treatment remains the standard of care. HCV patients without response or with contraindications to IFN-based therapy have no alternative options. However, many patients buy DAAs, especially the generic forms of sofosbuvir, from other countries or areas. Under these circumstances, the use of these drugs may cause many predictable and unpredictable problems in ethics, law and medical practice. Given the obstacles of legal accessibility to DAAs and the potential problems of obtaining and using DAAs in China, the early launching of the DAAs in China or the legalization of buying drugs from areas outside China and using these drugs in China is an urgent issue and needs to be dealt with as soon as possible, in the interest of the patients.

  6. CROI 2016: Viral Hepatitis and Liver Fibrosis.

    PubMed

    Luetkemeyer, Anne F; Wyles, David L

    2016-01-01

    At the 2016 Conference on Retroviruses and Opportunistic Infections (CROI) in Boston, Massachusetts, hepatitis C virus (HCV) infection remained a major theme in the context of HIV-associated liver disease, although other causes of liver disease garnered increased attention, including fatty liver disease, hepatitis B, and the impact of HIV disease itself on the liver. Although no data from phase III studies of HCV direct-acting antiviral (DAA) drugs for the treatment of HIV/HCV coinfection were presented at CROI 2016, a broad range of HCV DAA-related topics were presented, including accumulating experience with real-world performance of DAA-based regimens outside of clinical trials, drug interactions between DAA and antiretroviral drugs, treatment of acute HCV infection, and retreatment of individuals whose DAA-based regimens failed and those in whom resistance to DAA drugs emerged. A summary of select abstracts from CROI 2016 is presented, including discussion of clinical relevance where appropriate and areas for future research.

  7. Current treatment of chronic hepatitis C in China: Dilemma and potential problems

    PubMed Central

    Han, Qun-Ying; Liu, Zheng-Wen

    2016-01-01

    Major advances have been made in the treatment of chronic hepatitis C virus (HCV) infection with the advent of direct-acting antiviral agents (DAAs). China has the most cases of HCV infection worldwide, but none of the DAAs has been approved in mainland China so far, and interferon (IFN)-α-based treatment remains the standard of care. HCV patients without response or with contraindications to IFN-based therapy have no alternative options. However, many patients buy DAAs, especially the generic forms of sofosbuvir, from other countries or areas. Under these circumstances, the use of these drugs may cause many predictable and unpredictable problems in ethics, law and medical practice. Given the obstacles of legal accessibility to DAAs and the potential problems of obtaining and using DAAs in China, the early launching of the DAAs in China or the legalization of buying drugs from areas outside China and using these drugs in China is an urgent issue and needs to be dealt with as soon as possible, in the interest of the patients. PMID:27217693

  8. Conjugation of a nonspecific antiviral sapogenin with a specific HIV fusion inhibitor: a promising strategy for discovering new antiviral therapeutics.

    PubMed

    Wang, Chao; Lu, Lu; Na, Heya; Li, Xiangpeng; Wang, Qian; Jiang, Xifeng; Xu, Xiaoyu; Yu, Fei; Zhang, Tianhong; Li, Jinglai; Zhang, Zhenqing; Zheng, Baohua; Liang, Guodong; Cai, Lifeng; Jiang, Shibo; Liu, Keliang

    2014-09-11

    Triterpene saponins are a major group of active components in natural products with nonspecific antiviral activities, while T20 peptide (enfuvirtide), which contains a helix zone-binding domain (HBD), is a gp41-specific HIV-1 fusion inhibitor. In this paper, we report the design, synthesis, and structure-activity relationship (SAR) of a group of hybrid molecules in which bioactive triterpene sapogenins were covalently attached to the HBD-containing peptides via click chemistry. We found that either the triterpenes or peptide part alone showed weak activity against HIV-1 Env-mediated cell-cell fusion, while the hybrids generated a strong cooperative effect. Among them, P26-BApc exhibited anti-HIV-1 activity against both T20-sensitive and -resistant HIV-1 strains and improved pharmacokinetic properties. These results suggest that this scaffold design is a promising strategy for developing new HIV-1 fusion inhibitors and possibly novel antiviral therapeutics against other viruses with class I fusion proteins.

  9. Antiviral immunity via RIG-I-mediated recognition of RNA bearing 5′-diphosphates

    PubMed Central

    Deddouche, Safia; Pruijssers, Andrea J.; Zillinger, Thomas; Goldeck, Marion; Schuberth, Christine; Van der Veen, Annemarthe G.; Fujimura, Tsutomu; Rehwinkel, Jan; Iskarpatyoti, Jason A.; Barchet, Winfried; Ludwig, Janos; Dermody, Terence S.; Hartmann, Gunther; Reis e Sousa, Caetano

    2014-01-01

    SUMMARY Mammalian cells possess mechanisms to detect and defend themselves from invading viruses. In the cytosol, the RIG-I-like receptors (RLRs), RIG-I (retinoic acid-inducible gene I; encoded by DDX58) and MDA5 (melanoma differentiation-associated gene 5; encoded by IFIH1) sense atypical RNAs associated with virus infection1,2. Detection triggers a signalling cascade via the adaptor MAVS that culminates in the production of type I interferons (IFN-α/β; hereafter IFN), key antiviral cytokines. RIG-I and MDA5 are activated by distinct viral RNA structures and much evidence indicates that RIG-I responds to RNAs bearing a triphosphate (ppp) moiety in conjunction with a blunt-ended, base-paired region at the 5′-end (reviewed in 1-3). Here we show that RIG-I also mediates antiviral responses to RNAs bearing 5′-diphosphates (5′pp). Genomes from mammalian reoviruses with 5′pp termini, 5′pp-RNA isolated from yeast L-A virus, and base-paired 5′pp-RNAs made by in vitro transcription or chemical synthesis, all bind to RIG-I and serve as RIG-I agonists. Furthermore, a RIG-I-dependent response to 5′pp-RNA is essential for controlling reovirus infection in cultured cells and in mice. Thus, the minimal determinant for RIG-I recognition is a base-paired RNA with 5′pp. Such RNAs are found in some viruses but not uninfected cells, indicating that recognition of 5′pp-RNA, like that of 5′ppp-RNA, acts as a powerful means of self/non-self discrimination by the innate immune system. PMID:25119032

  10. The Synthetic Antiviral Drug Arbidol Inhibits Globally Prevalent Pathogenic Viruses

    PubMed Central

    Pécheur, Eve-Isabelle; Borisevich, Viktoriya; Halfmann, Peter; Morrey, John D.; Smee, Donald F.; Prichard, Mark; Mire, Chad E.; Kawaoka, Yoshihiro; Geisbert, Thomas W.

    2016-01-01

    ABSTRACT Arbidol (ARB) is a synthetic antiviral originally developed to combat influenza viruses. ARB is currently used clinically in several countries but not in North America. We have previously shown that ARB inhibits in vitro hepatitis C virus (HCV) by blocking HCV entry and replication. In this report, we expand the list of viruses that are inhibited by ARB and demonstrate that ARB suppresses in vitro infection of mammalian cells with Ebola virus (EBOV), Tacaribe arenavirus, and human herpesvirus 8 (HHV-8). We also confirm suppression of hepatitis B virus and poliovirus by ARB. ARB inhibited EBOV Zaire Kikwit infection when added before or at the same time as virus infection and was less effective when added 24 h after EBOV infection. Experiments with recombinant vesicular stomatitis virus (VSV) expressing the EBOV Zaire glycoprotein showed that infection was inhibited by ARB at early stages, most likely at the level of viral entry into host cells. ARB inhibited HHV-8 replication to a similar degree as cidofovir. Our data broaden the spectrum of antiviral efficacy of ARB to include globally prevalent viruses that cause significant morbidity and mortality. IMPORTANCE There are many globally prevalent viruses for which there are no licensed vaccines or antiviral medicines. Some of these viruses, such as Ebola virus or members of the arenavirus family, rapidly cause severe hemorrhagic diseases that can be fatal. Other viruses, such as hepatitis B virus or human herpesvirus 8 (HHV-8), establish persistent infections that cause chronic illnesses, including cancer. Thus, finding an affordable, effective, and safe drug that blocks many viruses remains an unmet medical need. The antiviral drug arbidol (ARB), already in clinical use in several countries as an anti-influenza treatment, has been previously shown to suppress the growth of many viruses. In this report, we expand the list of viruses that are blocked by ARB in a laboratory setting to include Ebola virus

  11. Caenorhabditis elegans RIG-I Homolog Mediates Antiviral RNA Interference Downstream of Dicer-Dependent Biogenesis of Viral Small Interfering RNAs

    PubMed Central

    Coffman, Stephanie R.; Lu, Jinfeng; Guo, Xunyang; Zhong, Jing; Broitman-Maduro, Gina; Li, Wan-Xiang; Lu, Rui; Maduro, Morris

    2017-01-01

    ABSTRACT Dicer enzymes process virus-specific double-stranded RNA (dsRNA) into small interfering RNAs (siRNAs) to initiate specific antiviral defense by related RNA interference (RNAi) pathways in plants, insects, nematodes, and mammals. Antiviral RNAi in Caenorhabditis elegans requires Dicer-related helicase 1 (DRH-1), not found in plants and insects but highly homologous to mammalian retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), intracellular viral RNA sensors that trigger innate immunity against RNA virus infection. However, it remains unclear if DRH-1 acts analogously to initiate antiviral RNAi in C. elegans. Here, we performed a forward genetic screen to characterize antiviral RNAi in C. elegans. Using a mapping-by-sequencing strategy, we uncovered four loss-of-function alleles of drh-1, three of which caused mutations in the helicase and C-terminal domains conserved in RLRs. Deep sequencing of small RNAs revealed an abundant population of Dicer-dependent virus-derived small interfering RNAs (vsiRNAs) in drh-1 single and double mutant animals after infection with Orsay virus, a positive-strand RNA virus. These findings provide further genetic evidence for the antiviral function of DRH-1 and illustrate that DRH-1 is not essential for the sensing and Dicer-mediated processing of the viral dsRNA replicative intermediates. Interestingly, vsiRNAs produced by drh-1 mutants were mapped overwhelmingly to the terminal regions of the viral genomic RNAs, in contrast to random distribution of vsiRNA hot spots when DRH-1 is functional. As RIG-I translocates on long dsRNA and DRH-1 exists in a complex with Dicer, we propose that DRH-1 facilitates the biogenesis of vsiRNAs in nematodes by catalyzing translocation of the Dicer complex on the viral long dsRNA precursors. PMID:28325765

  12. Cross-Species Antiviral Activity of Goose Interferons against Duck Plague Virus Is Related to Its Positive Self-Feedback Regulation and Subsequent Interferon Stimulated Genes Induction

    PubMed Central

    Zhou, Hao; Chen, Shun; Zhou, Qin; Wei, Yunan; Wang, Mingshu; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Liu, Fei; Yang, Qiao; Wu, Ying; Sun, Kunfeng; Chen, Xiaoyue; Cheng, Anchun

    2016-01-01

    Interferons are a group of antiviral cytokines acting as the first line of defense in the antiviral immunity. Here, we describe the antiviral activity of goose type I interferon (IFNα) and type II interferon (IFNγ) against duck plague virus (DPV). Recombinant goose IFNα and IFNγ proteins of approximately 20 kDa and 18 kDa, respectively, were expressed. Following DPV-enhanced green fluorescent protein (EGFP) infection of duck embryo fibroblast cells (DEFs) with IFNα and IFNγ pre-treatment, the number of viral gene copies decreased more than 100-fold, with viral titers dropping approximately 100-fold. Compared to the control, DPV-EGFP cell positivity was decreased by goose IFNα and IFNγ at 36 hpi (3.89%; 0.79%) and 48 hpi (17.05%; 5.58%). In accordance with interferon-stimulated genes being the “workhorse” of IFN activity, the expression of duck myxovirus resistance (Mx) and oligoadenylate synthetases-like (OASL) was significantly upregulated (p < 0.001) by IFN treatment for 24 h. Interestingly, duck cells and goose cells showed a similar trend of increased ISG expression after goose IFNα and IFNγ pretreatment. Another interesting observation is that the positive feedback regulation of type I IFN and type II IFN by goose IFNα and IFNγ was confirmed in waterfowl for the first time. These results suggest that the antiviral activities of goose IFNα and IFNγ can likely be attributed to the potency with which downstream genes are induced by interferon. These findings will contribute to our understanding of the functional significance of the interferon antiviral system in aquatic birds and to the development of interferon-based prophylactic and therapeutic approaches against viral disease. PMID:27438848

  13. Natural variants of cytotoxic epitopes are T-cell receptor antagonists for antiviral cytotoxic T cells

    NASA Astrophysics Data System (ADS)

    Bertoletti, Antonio; Sette, Alessandro; Chisari, Francis V.; Penna, Amalia; Levrero, Massimo; Carli, Marco De; Fiaccadori, Franco; Ferrari, Carlo

    1994-06-01

    IT has been suggested that mutations within immunodominant cytotoxic T-lymphocyte (CTL) epitopes may be exploited by viruses to evade protective immune responses critical for clearance1-4. Viral escape could originate from passive mechanisms, such as mutations within crucial CTL epitopes, either affecting major histocompatibility complex binding or T-cell antigen receptor (TCR) recognition. Additionally, it has recently been shown that substitutions of TCR contact sites can yield analogue peptides that can still interact with the T-cell receptor but be unable to deliver a full stimulatory signal, thus inducing anergy5 or acting as an antagonist for the TCR6-8. We report here that hepatitis B virus isolates derived from two chronically infected patients display variant epitopes that act as natural TCR antagonists with the capacity to inhibit the CTL response to the wild-type epitope. During natural infection, TCR antagonist mutations of CTL epitopes could contribute to the development of viral persistence, especially if the antiviral CTL response is monospecific or the epitope is strongly immunodominant.

  14. Cell-based antiviral screening against coronaviruses: Developing virus-specific and broad-spectrum inhibitors

    PubMed Central

    Kilianski, Andy; Baker, Susan C.

    2014-01-01

    To combat the public health threat from emerging coronaviruses (CoV), the development of antiviral therapies with either virus-specific or pan-CoV activities is necessary. An important step in antiviral drug development is the screening of potential inhibitors in cell-based systems. The recent emergence of the Middle East respiratory syndrome (MERS)-CoV necessitates adapting methods that have been used to identify antivirals against the severe, acute respiratory syndrome (SARS)-CoV and developing new approaches to more efficiently screen antiviral drugs. In this article we review cell-based assays using infectious virus (BSL-3) and surrogate assays (BSL-2) that can be implemented to accelerate antiviral development against MERS-CoV and future emergent coronaviruses. This paper forms part of a series of invited articles in Antiviral Research on “From SARS to MERS: 10 years of research on highly pathogenic human coronaviruses.” PMID:24269477

  15. Novel cycloalkylthiophene-imine derivatives bearing benzothiazole scaffold: synthesis, characterization and antiviral activity evaluation.

    PubMed

    Ke, Shaoyong; Wei, Yanhong; Yang, Ziwen; Wang, Kaimei; Liang, Ying; Shi, Liqiao

    2013-09-15

    A series of novel cycloalkylthiophene-imine derivatives containing benzothiazole unit were designed, synthesized and evaluated for their anti-viral activities. The bio-evaluation results indicated that some of the target compounds (such as 5g, 5i, 5u) exhibited good to moderate antiviral effect on CVB5, ADV7 and EV71 viruses, however, these compounds did not have inhibition activity against H1N1 virus. Especially, the compounds 4c and 4d also exhibited high antiviral activities, which provide a new and efficient approach to evolve novel multi-functional antiviral agents by rational integration of active pharmacophores.

  16. Caenorhabditis elegans RIG-I Homolog Mediates Antiviral RNA Interference Downstream of Dicer-Dependent Biogenesis of Viral Small Interfering RNAs.

    PubMed

    Coffman, Stephanie R; Lu, Jinfeng; Guo, Xunyang; Zhong, Jing; Jiang, Hongshan; Broitman-Maduro, Gina; Li, Wan-Xiang; Lu, Rui; Maduro, Morris; Ding, Shou-Wei

    2017-03-21

    Dicer enzymes process virus-specific double-stranded RNA (dsRNA) into small interfering RNAs (siRNAs) to initiate specific antiviral defense by related RNA interference (RNAi) pathways in plants, insects, nematodes, and mammals. Antiviral RNAi in Caenorhabditis elegans requires Dicer-related helicase 1 (DRH-1), not found in plants and insects but highly homologous to mammalian retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), intracellular viral RNA sensors that trigger innate immunity against RNA virus infection. However, it remains unclear if DRH-1 acts analogously to initiate antiviral RNAi in C. elegans Here, we performed a forward genetic screen to characterize antiviral RNAi in C. elegans Using a mapping-by-sequencing strategy, we uncovered four loss-of-function alleles of drh-1, three of which caused mutations in the helicase and C-terminal domains conserved in RLRs. Deep sequencing of small RNAs revealed an abundant population of Dicer-dependent virus-derived small interfering RNAs (vsiRNAs) in drh-1 single and double mutant animals after infection with Orsay virus, a positive-strand RNA virus. These findings provide further genetic evidence for the antiviral function of DRH-1 and illustrate that DRH-1 is not essential for the sensing and Dicer-mediated processing of the viral dsRNA replicative intermediates. Interestingly, vsiRNAs produced by drh-1 mutants were mapped overwhelmingly to the terminal regions of the viral genomic RNAs, in contrast to random distribution of vsiRNA hot spots when DRH-1 is functional. As RIG-I translocates on long dsRNA and DRH-1 exists in a complex with Dicer, we propose that DRH-1 facilitates the biogenesis of vsiRNAs in nematodes by catalyzing translocation of the Dicer complex on the viral long dsRNA precursors.IMPORTANCE The helicase and C-terminal domains of mammalian RLRs sense intracellular viral RNAs to initiate the interferon-regulated innate immunity against RNA virus infection. Both of the domains from

  17. Synthesis and antiviral activity of azoles obtained from carbohydrates.

    PubMed

    Barradas, José Sebastián; Errea, María Inés; D'Accorso, Norma B; Sepúlveda, Claudia S; Talarico, Laura B; Damonte, Elsa B

    2008-09-22

    Herein we describe the synthesis of 1,2,4-triazolyl-3-thione;1,3,4-oxadiazole, and imidazo[2,1-b]thiazole derivatives from carbohydrates. The antiviral activity of these compounds was tested against Dengue and Junin virus (the etiological agent of Argentine hemorrhagic fever). The 3-(p-bromobenzoyl)-5-(1,2-O-isopropylidene-3-O-methyl-alpha-d-xylofuranos-5-ulos-5-yl)imidazo[2,1-b]thiazole was able to inhibit the replication of both viruses in Vero cells at concentration significantly lower than the CC(50).

  18. Henipavirus outbreaks to antivirals: the current status of potential therapeutics.

    PubMed

    Broder, Christopher C

    2012-04-01

    The henipaviruses, Hendra virus and Nipah virus, are classic examples of recently emerged viral zoonoses. In a relatively short time since their discoveries in the mid and late 1990s, respectively, a great deal of new information has been accumulated detailing their biology and certain unique characteristics. Their broad species tropism and abilities to cause severe and often fatal respiratory and/or neurologic disease in both animals and humans has sparked considerable interest in developing effective antiviral strategies to prevent or treat henipavirus infection and disease. Here, recent findings on the few most advanced henipavirus countermeasures are summarized and discussed.

  19. In Vitro Efficacy of Antiviral Compounds against Enterovirus D68

    PubMed Central

    Rhoden, Eric; Zhang, Mingyu; Nix, W. Allan

    2015-01-01

    In 2014, the United States experienced a large outbreak of severe respiratory illness associated with enterovirus D68 (EV-D68). We used a homogeneous, cell-based assay to assess the antiviral activity of compounds developed for EV/rhinovirus infection or other indications. Three of 15 compounds were highly active against all four strains tested (the prototype and three 2014 strains), with 50% effective concentrations of 0.0012 to 0.027 μM. Additional studies are needed to assess their in vivo efficacy against EV-D68. PMID:26149998

  20. 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.

  1. Ergotism associated with HIV antiviral protease inhibitor therapy.

    PubMed

    Baldwin, Zachary K; Ceraldi, Chris C

    2003-03-01

    Ergotism is a rare condition of acute vasospasm found classically in young and middle-aged women taking ergot alkaloid agents to treat migraine headache. We report the case of a young man with human immunodeficiency virus (HIV) positivity and describe the drug interaction between protease inhibitors and ergot alkaloid agents, which most likely predisposed to development of ergot toxicity. The HIV-positive population receiving antiviral therapy may be an under-recognized group at risk for ergotism through decreased hepatic metabolism of ergot preparations.

  2. Discovery of a Novel Series of Potent Non-Nucleoside Inhibitors of Hepatitis C Virus NS5B

    PubMed Central

    Schoenfeld, Ryan C.; Bourdet, David L.; Brameld, Ken A.; Chin, Elbert; de Vicente, Javier; Fung, Amy; Harris, Seth F.; Lee, Eun K.; Pogam, Sophie Le; Leveque, Vincent; Li, Jim; Lui, Alfred S-T.; Najera, Isabel; Rajyaguru, Sonal; Sangi, Michael; Steiner, Sandra; Talamas, Francisco X.; Taygerly, Joshua P.; Zhao, Junping

    2013-01-01

    Hepatitis C virus (HCV) is a major global public health problem. While the current standard of care, a direct-acting antiviral (DAA) protease inhibitor taken in combination with pegylated interferon and ribavirin, represents a major advancement in recent years, an unmet medical need still exists for treatment modalities that improve upon both efficacy and tolerability. Towards those ends, much effort has continued to focus on the discovery of new DAAs, with the ultimate goal to provide interferon-free combinations. The RNA-dependent RNA polymerase enzyme NS5B represents one such DAA therapeutic target for inhibition which has attracted much interest over the past decade. Herein, we report the discovery and optimization of a novel series of inhibitors of HCV NS5B, through the use of structure-based design applied to a fragment-derived starting point. Issues of potency, pharmacokinetics and early safety were addressed in order to provide a clinical candidate in fluoropyridone 19. PMID:24069953

  3. Hepatitis C treatment: where are we now?

    PubMed Central

    Burstow, Nicholas J; Mohamed, Zameer; Gomaa, Asmaa I; Sonderup, Mark W; Cook, Nicola A; Waked, Imam; Spearman, C Wendy; Taylor-Robinson, Simon D

    2017-01-01

    Chronic hepatitis C infection affects millions of people worldwide and confers significant morbidity and mortality. Effective treatment is needed to prevent disease progression and associated complications. Previous treatment options were limited to interferon and ribavirin (RBV) regimens, which gave low cure rates and were associated with unpleasant side effects. The era of direct-acting antiviral (DAA) therapies began with the development of first-generation NS3/4A protease inhibitors in 2011. They vastly improved outcomes for patients, particularly those with genotype 1 infection, the most prevalent genotype globally. Since then, a multitude of DAAs have been licensed for use, and outcomes for patients have improved further, with fewer side effects and cure rates approaching 100%. Recent regimens are interferon-free, and in many cases, RBV-free, and involve a combination of DAA agents. This review summarizes the treatment options currently available and discusses potential barriers that may delay the global eradication of hepatitis C. PMID:28255252

  4. Management of Antiviral Resistance in Chronic Hepatitis B

    PubMed Central

    Lim, Young-Suk

    2017-01-01

    The primary goal of therapy for chronic hepatitis B (CHB) is to prevent liver disease progression. Hepatitis B surface antigen (HBsAg) seroclearance or seroconversion is regarded as an optimal endpoint to discontinue treatment. However, HBsAg seroclearance occurs very rarely with nucleos(t)ide analog (NUC) treatment, and long-term, almost indefinite, NUC treatment is required for the majority of patients. In patients with drug-resistant hepatitis B virus (HBV), a combination of tenofovir disoproxil fumarate (TDF) and entecavir (ETV), which is currently regarded as the strongest combination therapy against HBV, would be potentially safe to prevent the emergence of additional HBV resistance mutations. However, long-term tolerance data are lacking, and cost may be an issue for combination therapies. Several recent, well-designed, randomized controlled trials have shown that TDF mono-therapy provides similar antiviral efficacy compared with the combination of TDF and ETV. Furthermore, no additional HBV resistance mutations emerged during TDF monotherapy for up to 96 weeks. Considering a comparable antiviral efficacy, extremely low risk of TDF-resistance, lower cost, and better safety potential, TDF monotherapy would be a reasonable choice for the treatment of drug-resistant patients with CHB. PMID:28183162

  5. 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

  6. RNAi and Antiviral Defense in the Honey Bee.

    PubMed

    Brutscher, Laura M; Flenniken, Michelle L

    2015-01-01

    Honey bees play an important agricultural and ecological role as pollinators of numerous agricultural crops and other plant species. Therefore, investigating the factors associated with high annual losses of honey bee colonies in the US is an important and active area of research. Pathogen incidence and abundance correlate with Colony Collapse Disorder- (CCD-) affected colonies in the US and colony losses in the US and in some European countries. Honey bees are readily infected by single-stranded positive sense RNA viruses. Largely dependent on the host immune response, virus infections can either remain asymptomatic or result in deformities, paralysis, or death of adults or larvae. RNA interference (RNAi) is an important antiviral defense mechanism in insects, including honey bees. Herein, we review the role of RNAi in honey bee antiviral defense and highlight some parallels between insect and mammalian immune systems. A more thorough understanding of the role of pathogens on honey bee health and the immune mechanisms bees utilize to combat infectious agents may lead to the development of strategies that enhance honey bee health and result in the discovery of additional mechanisms of immunity in metazoans.

  7. Arenaviruses and hantaviruses: from epidemiology and genomics to antivirals.

    PubMed

    Charrel, R N; Coutard, B; Baronti, C; Canard, B; Nougairede, A; Frangeul, A; Morin, B; Jamal, S; Schmidt, C L; Hilgenfeld, R; Klempa, B; de Lamballerie, X

    2011-05-01

    The arenaviruses and hantaviruses are segmented genome RNA viruses that are hosted by rodents. Due to their association with rodents, they are globally widespread and can infect humans via direct or indirect routes of transmission, causing considerable human morbidity and mortality. Nevertheless, despite their obvious and emerging importance as pathogens, there are currently no effective antiviral drugs (except ribavirin which proved effective against Lassa virus) with which to treat humans infected by any of these viruses. The EU-funded VIZIER project (Comparative Structural Genomics of Viral Enzymes Involved in Replication) was instigated with an ultimate view of contributing to the development of antiviral therapies for RNA viruses, including the arenaviruses and bunyaviruses. This review highlights some of the major features of the arenaviruses and hantaviruses that have been investigated during recent years. After describing their classification and epidemiology, we review progress in understanding the genomics as well as the structure and function of replicative enzymes achieved under the VIZIER program and the development of new disease control strategies.

  8. Antiviral Cystine Knot α-Amylase Inhibitors from Alstonia scholaris*

    PubMed Central

    Nguyen, Phuong Quoc Thuc; Ooi, Justin Seng Geap; Nguyen, Ngan Thi Kim; Wang, Shujing; Huang, Mei; Liu, Ding Xiang; Tam, James P.

    2015-01-01

    Cystine knot α-amylase inhibitors are cysteine-rich, proline-rich peptides found in the Amaranthaceae and Apocynaceae plant species. They are characterized by a pseudocyclic backbone with two to four prolines and three disulfides arranged in a knotted motif. Similar to other knottins, cystine knot α-amylase inhibitors are highly resistant to degradation by heat and protease treatments. Thus far, only the α-amylase inhibition activity has been described for members of this family. Here, we show that cystine knot α-amylase inhibitors named alstotides discovered from the Alstonia scholaris plant of the Apocynaceae family display antiviral activity. The alstotides (As1–As4) were characterized by both proteomic and genomic methods. All four alsotides are novel, heat-stable and enzyme-stable and contain 30 residues. NMR determination of As1 and As4 structures reveals their conserved structural fold and the presence of one or more cis-proline bonds, characteristics shared by other cystine knot α-amylase inhibitors. Genomic analysis showed that they contain a three-domain precursor, an arrangement common to other knottins. We also showed that alstotides are antiviral and cell-permeable to inhibit the early phase of infectious bronchitis virus and Dengue infection, in addition to their ability to inhibit α-amylase. Taken together, our results expand membership of cystine knot α-amylase inhibitors in the Apocynaceae family and their bioactivity, functional promiscuity that could be exploited as leads in developing therapeutics. PMID:26546678

  9. Antiviral activity of hemolymph of Podalia against rubella virus.

    PubMed

    Carvalho, N D; Mendonça, R Z; Oliveira, M I; Curti, S P; Barbosa, T F; Silva, P E; Taniwaki, N N; Tonelotto, M; Giovanni, D N S; Moraes, R H P; Figueiredo, C A

    2017-02-01

    Many active principles produced by animals, plants and microorganisms have been employed in the development of new drugs for the treatment of human diseases. Among animals known to produce pharmacologically active molecules that interfere in human cell physiology. Rubella virus (genus Rubivirus, family Togaviridae) is a single stranded RNA virus of positive genome polarity. Rubella virus infection of susceptible women during the first trimester of pregnancy often results in long-term virus persistence in the fetus causing multiple organ abnormalities. Potent antiviral activity against rubella virus (RV) has been observed in the hemolymph of Podalia sp. (Lepidoptera: Megalopygidae). This study evaluated the effect of hemolymph on RV infected Statens Serum Institute Rabbit Cornea (SIRC) cells. Results of cell viability and cell proliferation assays indicated that hemolymph was not toxic to cultured SIRC cells. Viral binding assay, antiviral assay, PCR, real-time PCR, and transmission electron microscopy were used to demonstrate that hemolymph in post-treatment could inhibit the production of infectious RV particles. Specifically, hemolymph was found to inhibit RV adsorption to the SIRC cells.

  10. Experimental rhinovirus infection in COPD: implications for antiviral therapies.

    PubMed

    Gunawardana, Natasha; Finney, Lydia; Johnston, Sebastian L; Mallia, Patrick

    2014-02-01

    Chronic obstructive pulmonary disease (COPD) is a major public health problem and will be one of the leading global causes of mortality over the coming decades. Much of the morbidity, mortality and health care costs of COPD are attributable to acute exacerbations, the commonest causes of which are respiratory infections. Respiratory viruses are frequently detected in COPD exacerbations but direct proof of a causative relationship has been lacking. We have developed a model of COPD exacerbation using experimental rhinovirus infection in COPD patients and this has established a causative relationship between virus infection and exacerbations. In addition it has determined some of the molecular mechanisms linking virus infections to COPD exacerbations and identified potential new therapeutic targets. This new data should stimulate research into the role of antiviral agents as potential treatments for COPD exacerbations. Testing of antiviral agents has been hampered by the lack of a small animal model for rhinovirus infection and experimental rhinovirus infection in healthy volunteers has been used to test treatments for the common cold. Experimental rhinovirus infection in COPD subjects offers the prospect of a model that can be used to evaluate the effects of new treatments for virus-induced COPD exacerbations, and provide essential data that can be used in making decisions regarding large scale clinical trials.

  11. Flexibility as a Strategy in Nucleoside Antiviral Drug Design.

    PubMed

    Peters, H L; Ku, T C; Seley-Radtke, K L

    2015-01-01

    As far back as Melville Wolfrom's acyclic sugar synthesis in the 1960's, synthesis of flexible nucleoside analogues have been an area of interest. This concept, however, went against years of enzyme-substrate binding theory. Hence, acyclic methodology in antiviral drug design did not take off until the discovery and subsequent FDA approval of such analogues as Acyclovir and Tenofovir. More recently, the observation that flexible nucleosides could overcome drug resistance spawned a renewed interest in the field of nucleoside drug design. The next generation of flexible nucleosides shifted the focus from the sugar moiety to the nucleobase. With analogues such as Seley-Radtke "fleximers", and Herdewijn's C5 substituted 2'-deoxyuridines, the area of base flexibility has seen great expansion. More recently, the marriage of these methodologies with acyclic sugars has resulted in a series of acyclic flex-base nucleosides with a wide range of antiviral properties, including some of the first to exhibit anti-coronavirus activity. Various flexible nucleosides and their corresponding nucleobases will be compared in this review.

  12. Danger, diversity and priming in innate antiviral immunity.

    PubMed

    Collins, Susan E; Mossman, Karen L

    2014-10-01

    The prototypic response to viral infection involves the recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), leading to the activation of transcription factors such as IRF3 and NFkB and production of type 1 IFN. While this response can lead to the induction of hundreds of IFN-stimulated genes (ISGs) and recruitment and activation of immune cells, such a comprehensive response is likely inappropriate for routine low level virus exposure. Moreover, viruses have evolved a plethora of immune evasion strategies to subvert antiviral signalling. There is emerging evidence that cells have developed very sensitive methods of detecting not only specific viral PAMPS, but also more general danger or stress signals associated with viral entry and replication. Such stress-induced cellular responses likely serve to prime cells to respond to further PAMP stimulation or allow for a rapid and localized intracellular response independent of IFN production and its potential immune sequelae. This review discusses diversity in innate antiviral players and pathways, the role of "danger" sensing, and how alternative pathways, such as the IFN-independent pathway, may serve to prime cells for further pathogen attack.

  13. Antiviral medication in sexually transmitted diseases. Part II: HIV.

    PubMed

    Majewska, Anna; Mlynarczyk-Bonikowska, Beata; Malejczyk, Magdalena; Mlynarczyk, Grazyna; Majewski, Slawomir

    2015-01-01

    This is a second part of a review under a main title Antiviral medication in sexually transmitted diseases. In the part we published in Mini Rev Med Chem. 2013,13(13):1837-45, we have described mechanisms of action and mechanism of resistance to antiviral agents used in genital herpes and genital HPV infection. The Part II review focuses on therapeutic options in HIV infection. In 1987, 6 years after the recognition of AIDS, the FDA approved the first drug against HIV--zidovudine. Since then a lot of antiretroviral drugs are available. The most effective treatment for HIV is highly active antiretroviral therapy--a combination of several antiretroviral medicines that cause a reduction of HIV blood concentration and often results in substantial recovery of impaired immunologic function. At present, there are over 20 drugs licensed and used for the treatment of HIV/AIDS, and these drugs are divided into one of six classes. Investigational agents include GS-7340, the prodrug of tenofovir and BMS-663068--the first in a novel class of drugs that blocks the binding of the HIV gp120 to the CD4 receptor.

  14. RNAi and Antiviral Defense in the Honey Bee

    PubMed Central

    Brutscher, Laura M.; Flenniken, Michelle L.

    2015-01-01

    Honey bees play an important agricultural and ecological role as pollinators of numerous agricultural crops and other plant species. Therefore, investigating the factors associated with high annual losses of honey bee colonies in the US is an important and active area of research. Pathogen incidence and abundance correlate with Colony Collapse Disorder- (CCD-) affected colonies in the US and colony losses in the US and in some European countries. Honey bees are readily infected by single-stranded positive sense RNA viruses. Largely dependent on the host immune response, virus infections can either remain asymptomatic or result in deformities, paralysis, or death of adults or larvae. RNA interference (RNAi) is an important antiviral defense mechanism in insects, including honey bees. Herein, we review the role of RNAi in honey bee antiviral defense and highlight some parallels between insect and mammalian immune systems. A more thorough understanding of the role of pathogens on honey bee health and the immune mechanisms bees utilize to combat infectious agents may lead to the development of strategies that enhance honey bee health and result in the discovery of additional mechanisms of immunity in metazoans. PMID:26798663

  15. Pandemic influenza: overview of vaccines and antiviral drugs.

    PubMed Central

    Cox, Manon M. J.

    2005-01-01

    Pandemic influenza has become a high priority item for all public health authorities. An influenza pandemic is believed to be imminent, and scientists agree that it will be a matter of when, where, and what will be the causative agent. Recently, most attention has been directed to human cases of avian influenza caused by a H5N1 avian influenza virus. An effective vaccine will be needed to substantially reduce the impact of an influenza pandemic. Current influenza vaccine manufacturing technology is not adequate to support vaccine production in the event of an avian influenza outbreak, and it has now become clear that new innovative production technology is required. Antiviral drugs, on the other hand, can play a very important role in slowing the disease spread but are in short supply and resistance has been a major issue. Here, we provide an update on the status of pandemic vaccine development and antiviral drugs. Finally, we conclude with some proposed areas of focus in pandemic vaccine preparedness. PMID:17132338

  16. Evasion of early antiviral responses by herpes simplex viruses.

    PubMed

    Suazo, Paula A; Ibañez, Francisco J; Retamal-Díaz, Angello R; Paz-Fiblas, Marysol V; Bueno, Susan M; Kalergis, Alexis M; González, Pablo A

    2015-01-01

    Besides overcoming physical constraints, such as extreme temperatures, reduced humidity, elevated pressure, and natural predators, human pathogens further need to overcome an arsenal of antimicrobial components evolved by the host to limit infection, replication and optimally, reinfection. Herpes simplex virus-1 (HSV-1) and herpes simplex virus-2 (HSV-2) infect humans at a high frequency and persist within the host for life by establishing latency in neurons. To gain access to these cells, herpes simplex viruses (HSVs) must replicate and block immediate host antiviral responses elicited by epithelial cells and innate immune components early after infection. During these processes, infected and noninfected neighboring cells, as well as tissue-resident and patrolling immune cells, will sense viral components and cell-associated danger signals and secrete soluble mediators. While type-I interferons aim at limiting virus spread, cytokines and chemokines will modulate resident and incoming immune cells. In this paper, we discuss recent findings relative to the early steps taking place during HSV infection and replication. Further, we discuss how HSVs evade detection by host cells and the molecular mechanisms evolved by these viruses to circumvent early antiviral mechanisms, ultimately leading to neuron infection and the establishment of latency.

  17. Antiviral activity of natural products extracted from marine organisms.

    PubMed

    Uzair, Bushra; Mahmood, Zahra; Tabassum, Sobia

    2011-01-01

    Many epidemics have broken out over the centuries. Hundreds and thousands of humans have died over a disease. Available treatments for infectious diseases have always been limited. Some infections are more deadly than the others, especially viral pathogens. These pathogens have continuously resisted all kinds of medical treatment, due to a need for new treatments to be developed. Drugs are present in nature and are also synthesized in vitro and they help in combating diseases and restoring health. Synthesizing drugs is a hard and time consuming task, which requires a lot of man power and financial aid. However, the natural compounds are just lying around on the earth, may it be land or water. Over a thousand novel compounds isolated from marine organisms are used as antiviral agents. Others are being pharmacologically tested. Today, over forty antiviral compounds are present in the pharmacological market. Some of these compounds are undergoing clinical and preclinical stages. Marine compounds are paving the way for a new trend in modern medicine.

  18. Antiviral Effects of Pyrrolidine Dithiocarbamate on Human Rhinoviruses

    PubMed Central

    Gaudernak, Elisabeth; Seipelt, Joachim; Triendl, Andrea; Grassauer, Andreas; Kuechler, Ernst

    2002-01-01

    Human rhinoviruses (HRVs) are the predominant cause of the common cold. The frequency of HRV infections in industrial countries and the lack of effective therapeutical treatment underline the importance of research for new antiviral substances. As viral infections are often accompanied by the generation of oxidative stress inside the infected cells, several redox-active substances were tested as potential antivirals. In the course of these studies it was discovered that pyrrolidine dithiocarbamate (PDTC) is an extremely potent compound against HRV and poliovirus infection in cell culture. Besides the ability to dramatically reduce HRV production by interfering with viral protein expression, PDTC promotes cell survival and abolishes cytopathic effects in infected cells. PDTC also protects cells against poliovirus infection. These effects were highly specific, as several other antioxidants (vitamin C, Trolox, 2-mercaptoethanol, and N-acetyl-l-cysteine) are inactive against HRV infection. Synthesis of HRV proteins and cleavage of eucaryotic initiation factor 4G responsible for host cell shutoff of cellular protein synthesis are severely inhibited in the presence of PDTC. PMID:12021333

  19. Antiviral Responses by Swine Primary Bronchoepithelial Cells Are Limited Compared to Human Bronchoepithelial Cells Following Influenza Virus Infection

    PubMed Central

    Hauser, Mary J.; Dlugolenski, Daniel; Culhane, Marie R.; Wentworth, David E.; Tompkins, S. Mark; Tripp, Ralph A.

    2013-01-01

    Swine generate reassortant influenza viruses because they can be simultaneously infected with avian and human influenza; however, the features that restrict influenza reassortment in swine and human hosts are not fully understood. Type I and III interferons (IFNs) act as the first line of defense against influenza virus infection of respiratory epithelium. To determine if human and swine have different capacities to mount an antiviral response the expression of IFN and IFN-stimulated genes (ISG) in normal human bronchial epithelial (NHBE) cells and normal swine bronchial epithelial (NSBE) cells was evaluated following infection with human (H3N2), swine (H1N1), and avian (H5N3, H5N2, H5N1) influenza A viruses. Expression of IFNλ and ISGs were substantially higher in NHBE cells compared to NSBE cells following H5 avian influenza virus infection compared to human or swine influenza virus infection. This effect was associated with reduced H5 avian influenza virus replication in human cells at late times post infection. Further, RIG-I expression was lower in NSBE cells compared to NHBE cells suggesting reduced virus sensing. Together, these studies identify key differences in the antiviral response between human and swine respiratory epithelium alluding to differences that may govern influenza reassortment. PMID:23875024

  20. The rigid amphipathic fusion inhibitor dUY11 acts through photosensitization of viruses.

    PubMed

    Vigant, Frederic; Hollmann, Axel; Lee, Jihye; Santos, Nuno C; Jung, Michael E; Lee, Benhur

    2014-02-01

    Rigid amphipathic fusion inhibitors (RAFIs) are lipophilic inverted-cone-shaped molecules thought to antagonize the membrane curvature transitions that occur during virus-cell fusion and are broad-spectrum antivirals against enveloped viruses (Broad-SAVE). Here, we show that RAFIs act like membrane-binding photosensitizers: their antiviral effect is dependent on light and the generation of singlet oxygen ((1)O(2)), similar to the mechanistic paradigm established for LJ001, a chemically unrelated class of Broad-SAVE. Photosensitization of viral membranes is a common mechanism that underlies these Broad-SAVE.

  1. Antiviral treatment prioritization in HCV-infected patients with extrahepatic manifestations – An Egyptian perspective

    PubMed Central

    El-Fishawy, Hussein; Saadi, Gamal; Hassaballa, May; Hussein, Mohamed; Doss, Wahid; Ragab, Gaafar; Barsoum, Rashad

    2016-01-01

    Egypt, the single country with highest incidence of HCV infection in the world, has embarked on a government-sponsored mass treatment program using several combinations of DAAs. Recognizing the importance of extrahepatic manifestations, independently of the hepatic, a subcommittee was assigned to develop national guidelines for respective prioritizing indications and protocols. It evaluated the benefit of treating patients with different extrahepatic manifestations, and reviewed relevant clinical trials and guidelines concerning DAA combinations available in Egypt. The latter included Sofosbuvir plus either peg-interferon, Simeprevir, Ledipasvir or daclatasvir, and the Viekera family comprising paritaprevir/ritonavir + ombitasvir with (GT-1) or without (GT-4) Dasabuvir. Any of these protocols may be used with or without Ribavirin according to indication. A blueprint was subjected to peer debate in dedicated workshops in two national meetings and subsequently to an online professional review, eventually leading to a final report that was adopted by the health authorities. Seven compelling and 10 optional indications were identified for treating patients with predominantly extrahepatic manifestations. The former include kidney disease at different stages, cryoglobulinemic vasculitis and non-Hodgkin lymphoma. Selected treatment protocols, were encoded and their use was prioritized on the basis of evidence of efficacy and safety. We concluded that any of the studied protocols may be used, preferably with ribavirin, for 12-week treatment in all patients with extrahepatic manifestations without cirrhosis and with eGFR above 30 ml/min/1.73 sqm. Ribavirin should be included in protocols for treating patients with compensated cirrhosis. Daclatasvir-based protocols are recommended for decompensated cirrhosis, while the Viekera family is recommended in patients with eGFR < 30 ml/min/1.73 sqm, including those on dialysis. In kidney-transplanted patents, caution is due

  2. Extraribosomal L13a Is a Specific Innate Immune Factor for Antiviral Defense

    PubMed Central

    Poddar, Darshana; Basu, Abhijit; Kour, Ravinder; Verbovetskaya, Valentina

    2014-01-01

    ABSTRACT We report a novel extraribosomal innate immune function of mammalian ribosomal protein L13a, whereby it acts as an antiviral agent. We found that L13a is released from the 60S ribosomal subunit in response to infection by respiratory syncytial virus (RSV), an RNA virus of the Pneumovirus genus and a serious lung pathogen. Unexpectedly, the growth of RSV was highly enhanced in L13a-knocked-down cells of various lineages as well as in L13a knockout macrophages from mice. In all L13a-deficient cells tested, translation of RSV matrix (M) protein was specifically stimulated, as judged by a greater abundance of M protein and greater association of the M mRNA with polyribosomes, while general translation was unaffected. In silico RNA folding analysis and translational reporter assays revealed a putative hairpin in the 3′untranslated region (UTR) of M mRNA with significant structural similarity to the cellular GAIT (gamma-activated inhibitor of translation) RNA hairpin, previously shown to be responsible for assembling a large, L13a-containing ribonucleoprotein complex that promoted translational silencing in gamma interferon (IFN-γ)-activated myeloid cells. However, RNA-protein interaction studies revealed that this complex, which we named VAIT (respiratory syncytial virus-activated inhibitor of translation) is functionally different from the GAIT complex. VAIT is the first report of an extraribosomal L13a-mediated, IFN-γ-independent innate antiviral complex triggered in response to virus infection. We provide a model in which the VAIT complex strongly hinders RSV replication by inhibiting the translation of the rate-limiting viral M protein, which is a new paradigm in antiviral defense. IMPORTANCE The innate immune mechanisms of host cells are diverse in nature and act as a broad-spectrum cellular defense against viruses. Here, we report a novel innate immune mechanism functioning against respiratory syncytial virus (RSV), in which the cellular ribosomal

  3. Hypericum in Infection: Identification of Anti-viral and Anti-inflammatory Constituents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Iowa Center for Research on Botanical Dietary Supplements seeks to optimize Echinacea, Hypericum and Prunella supplements for human-health benefit, focusing on anti-viral, anti-inflammatory and anti-pain effects. This paper reports on ongoing anti-viral and anti-inflammatory studies on Hypericu...

  4. Antiviral effect of diammonium glycyrrhizinate on cell infection by porcine parvovirus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  5. Healthcare system cost evaluation of antiviral stockpiling for pandemic influenza preparedness.

    PubMed

    Li, Yang; Hsu, Edbert B; Links, Jonathan M

    2010-06-01

    Healthcare workers need to be protected during a severe influenza outbreak; therefore, we evaluated 4 different antiviral strategies: (1) using antiviral medication for outbreak prophylaxis of all hospital employees; (2) using antiviral medication for postexposure prophylaxis (PEP) or treatment of all hospital employees; (3) using a combination of antiviral medication for outbreak prophylaxis of high-risk clinical staff and postexposure prophylaxis or treatment for all other staff; and (4) using antiviral medication for postexposure prophylaxis or treatment of high-risk clinical staff only. Three different purchasing options were applied to each of the 4 antiviral strategies: (1) just-in-time purchase during a severe influenza outbreak, (2) prepandemic stockpiling, or (3) stockpiling through contracts with pharmaceutical manufacturers to reserve a predetermined antiviral supply. Although outbreak prophylaxis of all hospital employees would offer the maximum protection, the large costs associated with such a purchase make this option unrealistic and impractical. In addition, even though postexposure prophylaxis or treatment of only high-risk clinical staff would incur the least expense, the assumed level of protection if these options were offered only to high-risk clinical staff may not be sufficient to maintain routine hospital operations, since needed non-high-risk staff would not be protected. Considering the potential benefits and drawbacks of stockpiling antiviral medication from a cost perspective, it does not appear feasible for hospitals to stockpile antiviral medication in large quantities prior to a severe influenza outbreak. This article focuses on the financial viability of stockpiling antiviral medication, but the potential impact of other factors on the decision to stockpile was also considered and will be explored in future analyses. While legal hurdles related to prescribing, storing, and dispensing antiviral medication can be addressed

  6. Further iinvestigations on the antiviral activities of medicinal plants of togo.

    PubMed

    Hudson, J B; Anani, K; Lee, M K; de Souza, C; Arnason, J T; Gbeassor, M

    2000-01-01

    Further studies were done on the antiviral activities of 10 species of Togolese medicinal plants, previously shown to possess activity against herpes simplex virus (HSV). The dominant activity in all cases was virucidal (direct inactivation of virus particles), although Adansonia digitata extracts also appeared to have intracellular antiviral activities as well, which could indicate the presence of multiple antiviral compounds, or a single compound with multiple actions. In the seven most active extracts, the anti-HSV activity was considerably enhanced by light, especially UVA (long wavelength UV), although they all showed "dark" antiviral activity as well. Thus, all the extracts contained antiviral photosensitizers. In all tests, the root-bark and leaf extracts of A. digitata were the most potent.

  7. 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.

  8. Cytokine Synergy: an underappreciated contributor to innate anti-viral immunity

    PubMed Central

    Bartee, Eric; McFadden, Grant

    2013-01-01

    Inflammatory cytokines, such as tumor necrosis factor and the members of the interferon family, are potent mediators of the innate anti-viral immune response. The intracellular anti-viral states resulting from treatment of cultured cells with each of these molecules independently has been well studied; but, within complex tissues, the early inflammatory response is likely mediated by simultaneously expressed mixures of these, and other, protective anti-viral cytokines. Such cytokine mixtures have been shown to induce potently synergistic anti-viral responses in vitro which are more complex than the simple summation of the individual cytokine response profiles. The physiological role of this ‘cytokine synergy’, however, remains largely unappreciated in vivo. This brief commentary will attempt to summarize the potential effects and mechanisms of anti-viral cytokine synergy as well as present several ‘real-world’ applications where this phenomenon might play an important role. PMID:23693158

  9. Viral evasion mechanisms of early antiviral responses involving regulation of ubiquitin pathways.

    PubMed

    Rajsbaum, Ricardo; García-Sastre, Adolfo

    2013-08-01

    Early innate and cell-intrinsic responses are essential to protect host cells against pathogens. In turn, viruses have developed sophisticated mechanisms to establish productive infections by counteracting host innate immune responses. Increasing evidence indicates that these antiviral factors may have a dual role by directly inhibiting viral replication as well as by sensing and transmitting signals to induce antiviral cytokines. Recent studies have pointed at new, unappreciated mechanisms of viral evasion of host innate protective responses including manipulating the host ubiquitin (Ub) system. Virus-mediated inhibition of antiviral factors by Ub-dependent degradation is emerging as a crucial mechanism for evading the antiviral response. In addition, recent studies have uncovered new mechanisms by which virus-encoded proteins inhibit Ub and Ub-like (Ubl) modification of host proteins involved in innate immune signaling pathways. Here we discuss recent findings and novel strategies that viruses have developed to counteract these early innate antiviral defenses.

  10. Preparation, characterization and in vitro antiviral activity evaluation of foscarnet-chitosan nanoparticles.

    PubMed

    Russo, E; Gaglianone, N; Baldassari, S; Parodi, B; Cafaggi, S; Zibana, C; Donalisio, M; Cagno, V; Lembo, D; Caviglioli, G

    2014-06-01

    A new nanoparticulate system for foscarnet delivery was prepared and evaluated. Nanoparticles were obtained by ionotropic gelation of chitosan induced by foscarnet itself, acting as an ionotropic agent in a manner similar to tripolyphosphate anion. A Doehlert design allowed finding the suitable experimental conditions. Nanoparticles were between 200 and 300nm in diameter (around 450nm after redispersion). Nanoparticle size increased after 5h, but no size increase was observed after 48h when nanoparticles were crosslinked with glutaraldehyde. Zeta potential values of noncrosslinked and crosslinked nanoparticles were between 20 and 25mV, while drug loading of noncrosslinked nanoparticles was about 40% w/w (55% w/w for crosslinked nanoparticles). Nanoparticle yield was around 25% w/w. Crosslinked nanoparticles showed a controlled drug release. Foscarnet released from nanoparticles maintained the antiviral activity of the free drug when tested in vitro against lung fibroblasts (HELF) cells infected with HCMV strain AD-169. Moreover, nanoparticles showed no toxicity on non-infected HELF cells. These nanoparticles may represent a delivery system that could improve the therapeutic effect of foscarnet.

  11. Discovery of berberine, abamectin and ivermectin as antivirals against chikungunya and other alphaviruses.

    PubMed

    Varghese, Finny S; Kaukinen, Pasi; Gläsker, Sabine; Bespalov, Maxim; Hanski, Leena; Wennerberg, Krister; Kümmerer, Beate M; Ahola, Tero

    2016-02-01

    Chikungunya virus (CHIKV) is an arthritogenic arbovirus of the Alphavirus genus, which has infected millions of people after its re-emergence in the last decade. In this study, a BHK cell line containing a stable CHIKV replicon with a luciferase reporter was used in a high-throughput platform to screen approximately 3000 compounds. Following initial validation, 25 compounds were chosen as primary hits for secondary validation with wild type and reporter CHIKV infection, which identified three promising compounds. Abamectin (EC50 = 1.5 μM) and ivermectin (EC50 = 0.6 μM) are fermentation products generated by a soil dwelling actinomycete, Streptomyces avermitilis, whereas berberine (EC50 = 1.8 μM) is a plant-derived isoquinoline alkaloid. They inhibited CHIKV replication in a dose-dependent manner and had broad antiviral activity against other alphaviruses--Semliki Forest virus and Sindbis virus. Abamectin and ivermectin were also active against yellow fever virus, a flavivirus. These compounds caused reduced synthesis of CHIKV genomic and antigenomic viral RNA as well as downregulation of viral protein expression. Time of addition experiments also suggested that they act on the replication phase of the viral infectious cycle.

  12. An M2-V27A channel blocker demonstrates potent in vitro and in vivo antiviral activities against amantadine-sensitive and -resistant influenza A viruses.

    PubMed

    Hu, Yanmei; Musharrafieh, Rami; Ma, Chunlong; Zhang, Jiantao; Smee, Donald F; DeGrado, William F; Wang, Jun

    2017-04-01

    Adamantanes such as amantadine (1) and rimantadine (2) are FDA-approved anti-influenza drugs that act by inhibiting the wild-type M2 proton channel from influenza A viruses, thereby inhibiting the uncoating of the virus. Although adamantanes have been successfully used for more than four decades, their efficacy was curtailed by emerging drug resistance. Among the limited number of M2 mutants that confer amantadine resistance, the M2-V27A mutant was found to be the predominant mutant under drug selection pressure, thereby representing a high profile antiviral drug target. Guided by molecular dynamics simulations, we previously designed first-in-class M2-V27A inhibitors. One of the potent lead compounds, spiroadamantane amine (3), inhibits both the M2-WT and M2-V27A mutant with IC50 values of 18.7 and 0.3 μM, respectively, in in vitro electrophysiological assays. Encouraged by these findings, in this study we further examine the in vitro and in vivo antiviral activity of compound 3 in inhibiting both amantadine-sensitive and -resistant influenza A viruses. Compound 3 not only had single to sub-micromolar EC50 values against M2-WT- and M2-V27A-containing influenza A viruses in antiviral assays, but also rescued mice from lethal viral infection by either M2-WT- or M2-V27A-containing influenza A viruses. In addition, we report the design of two analogs of compound 3, and one was found to have improved in vitro antiviral activity over compound 3. Collectively, this study represents the first report demonstrating the in vivo antiviral efficacy of inhibitors targeting M2 mutants. The results suggest that inhibitors targeting drug-resistant M2 mutants are promising antiviral drug candidates worthy of further development.

  13. Murine cytomegalovirus resistant to antivirals has genetic correlates with human cytomegalovirus.

    PubMed

    Scott, G M; Ng, H-L; Morton, C J; Parker, M W; Rawlinson, W D

    2005-08-01

    Human cytomegalovirus (HCMV) resistance to antivirals is a significant clinical problem. Murine cytomegalovirus (MCMV) infection of mice is a well-described animal model for in vivo studies of CMV pathogenesis, although the mechanisms of MCMV antiviral susceptibility need elucidation. Mutants resistant to nucleoside analogues aciclovir, adefovir, cidofovir, ganciclovir, penciclovir and valaciclovir, and the pyrophosphate analogue foscarnet were generated by in vitro passage of MCMV (Smith) in increasing concentrations of antiviral. All MCMV antiviral resistant mutants contained DNA polymerase mutations identical or similar to HCMV DNA polymerase mutations known to confer antiviral resistance. Mapping of the mutations onto an MCMV DNA polymerase three-dimensional model generated using the Thermococcus gorgonarius Tgo polymerase crystal structure showed that the DNA polymerase mutations potentially confer resistance through changes in regions surrounding a catalytic aspartate triad. The ganciclovir-, penciclovir- and valaciclovir-resistant isolates also contained mutations within MCMV M97 identical or similar to recognized GCV-resistant mutations of HCMV UL97 protein kinase, and demonstrated cross-resistance to antivirals of the same class. This strongly suggests that MCMV M97 has a similar role to HCMV UL97 in the phosphorylation of nucleoside analogue antivirals. All MCMV mutants demonstrated replication-impaired phenotypes, with the lowest titre and plaque size observed for isolates containing mutations in both DNA polymerase and M97. These findings indicate DNA polymerase and protein kinase regions of potential importance for antiviral susceptibility and replication. The similarities between MCMV and HCMV mutations that arise under antiviral selective pressure increase the utility of MCMV as a model for in vivo studies of CMV antiviral resistance.

  14. Simultaneous Antibiofilm and Antiviral Activities of an Engineered Antimicrobial Peptide during Virus-Bacterium Coinfection

    PubMed Central

    Melvin, Jeffrey A.; Lashua, Lauren P.; Kiedrowski, Megan R.; Yang, Guanyi; Deslouches, Berthony; Montelaro, Ronald C.

    2016-01-01

    formed by the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogen Pseudomonas aeruginosa during coinfection with respiratory syncytial virus. We also observed antiviral activity, indicating the ability of engineered antimicrobial peptides to act as cross-kingdom single-molecule combination therapies. PMID:27303744

  15. Griffithsin: An Antiviral Lectin with Outstanding Therapeutic Potential

    PubMed Central

    Lusvarghi, Sabrina; Bewley, Carole A.

    2016-01-01

    Griffithsin (GRFT), an algae-derived lectin, is one of the most potent viral entry inhibitors discovered to date. It is currently being developed as a microbicide with broad-spectrum activity against several enveloped viruses. GRFT can inhibit human immunodeficiency virus (HIV) infection at picomolar concentrations, surpassing the ability of most anti-HIV agents. The potential to inhibit other viruses as well as parasites has also been demonstrated. Griffithsin’s antiviral activity stems from its ability to bind terminal mannoses present in high-mannose oligosaccharides and crosslink these glycans on the surface of the viral envelope glycoproteins. Here, we review structural and biochemical studies that established mode of action and facilitated construction of GRFT analogs, mechanisms that may lead to resistance, and in vitro and pre-clinical results that support the therapeutic potential of this lectin. PMID:27783038

  16. Antiviral activity of squalamine: Role of electrostatic membrane binding

    NASA Astrophysics Data System (ADS)

    Beckerman, Bernard; Qu, Wei; Mishra, Abhijit; Zasloff, Michael; Wong, Gerard; Luijten, Erik

    2012-02-01

    Recent workootnotetextM. Zasloff et al., Proc. Nat. Acad. Sci. (USA) 108, 15978 (2011). has demonstrated that squalamine, a molecule found in the liver of sharks, exhibits broad-spectrum antiviral properties. It has been proposed that this activity results from the charge-density matching of squalamine and phospholipid membranes, causing squalamine to bind to membranes and displace proteins such as Rac1 that are crucial for the viral replication cycle. Here we investigate this hypothesis by numerical simulation of a coarse-grained model for the competition between Rac1 and squalamine in binding affinity to a flat lipid bilayer. We perform free-energy calculations to test the ability of squalamine to condense stacked bilayer systems and thereby displace bulkier Rac1 molecules. We directly compare our findings to small-angle x-ray scattering results for the same setup.

  17. Mucin biopolymers as broad-spectrum antiviral agents

    PubMed Central

    Lieleg, Oliver; Lieleg, Corinna; Bloom, Jesse; Buck, Christopher B.; Ribbeck, Katharina

    2012-01-01

    Mucus is a porous biopolymer matrix that coats all wet epithelia in the human body and serves as the first line of defense against many pathogenic bacteria and viruses. However, under certain conditions viruses are able to penetrate this infection barrier, which compromises the protective function of native mucus. Here, we find that isolated porcine gastric mucin polymers, key structural components of native mucus, can protect an underlying cell layer from infection by small viruses such as human papillomavirus (HPV), Merkel cell polyomavirus (MCV), or a strain of influenza A virus. Single particle analysis of virus mobility inside the mucin barrier reveals that this shielding effect is in part based on a retardation of virus diffusion inside the biopolymer matrix. Our findings suggest that purified mucins may be used as a broad-range antiviral supplement to personal hygiene products, baby formula or lubricants to support our immune system. PMID:22475261

  18. Atomic- Resolution Crystal Structure of the Antiviral Lectin Scytovirin

    SciTech Connect

    Moulaei,T.; Botos, I.; Ziolkowska, N.; Bokesch, H.; Krumpe, L.; McKee, T.; O'Keefe, B.; Dauter, Z.; Wlodawer, A.

    2007-01-01

    The crystal structures of the natural and recombinant antiviral lectin scytovirin (SVN) were solved by single-wavelength anomalous scattering and refined with data extending to 1.3 Angstroms and 1.0 Angstroms resolution, respectively. A molecule of SVN consists of a single chain 95 amino acids long, with an almost perfect sequence repeat that creates two very similar domains (RMS deviation 0.25 Angstroms for 40 pairs of Ca atoms). The crystal structure differs significantly from a previously published NMR structure of the same protein, with the RMS deviations calculated separately for the N- and C-terminal domains of 5.3 Angstroms and 3.7 Angstroms, respectively, and a very different relationship between the two domains. In addition, the disulfide bonding pattern of the crystal structures differs from that described in the previously published mass spectrometry and NMR studies.

  19. The priorities for antiviral drug resistance surveillance and research.

    PubMed

    Pillay, Deenan

    2007-08-01

    The number of available antiviral drugs is growing fast. The emergence of drug-resistant viruses is well documented as a cause for drug failure. Such viruses also carry the potential for transmission, the risks for which vary according to specific viral transmission dynamics. This potential is best described for HIV and influenza. Resistance to the new generation of hepatitis C virus inhibitors is also likely to become a cause for concern. The priorities for future action to limit resistance include application of sophisticated surveillance mechanisms linked to detailed virological data, development of optimal treatment regimens (e.g. combination therapies) to limit emergence of resistance, and a focus on prevention strategies to prevent transmission.

  20. DOCK8 regulates lymphocyte shape integrity for skin antiviral immunity.

    PubMed

    Zhang, Qian; Dove, Christopher G; Hor, Jyh Liang; Murdock, Heardley M; Strauss-Albee, Dara M; Garcia, Jordan A; Mandl, Judith N; Grodick, Rachael A; Jing, Huie; Chandler-Brown, Devon B; Lenardo, Timothy E; Crawford, Greg; Matthews, Helen F; Freeman, Alexandra F; Cornall, Richard J; Germain, Ronald N; Mueller, Scott N; Su, Helen C

    2014-12-15

    DOCK8 mutations result in an inherited combined immunodeficiency characterized by increased susceptibility to skin and other infections. We show that when DOCK8-deficient T and NK cells migrate through confined spaces, they develop cell shape and nuclear deformation abnormalities that do not impair chemotaxis but contribute to a distinct form of catastrophic cell death we term cytothripsis. Such defects arise during lymphocyte migration in collagen-dense tissues when DOCK8, through CDC42 and p21-activated kinase (PAK), is unavailable to coordinate cytoskeletal structures. Cytothripsis of DOCK8-deficient cells prevents the generation of long-lived skin-resident memory CD8 T cells, which in turn impairs control of herpesvirus skin infections. Our results establish that DOCK8-regulated shape integrity of lymphocytes prevents cytothripsis and promotes antiviral immunity in the skin.

  1. Attacked from All Sides: RNA Decay in Antiviral Defense

    PubMed Central

    Molleston, Jerome M.; Cherry, Sara

    2017-01-01

    The innate immune system has evolved a number of sensors that recognize viral RNA (vRNA) to restrict infection, yet the full spectrum of host-encoded RNA binding proteins that target these foreign RNAs is still unknown. The RNA decay machinery, which uses exonucleases to degrade aberrant RNAs largely from the 5′ or 3′ end, is increasingly recognized as playing an important role in antiviral defense. The 5′ degradation pathway can directly target viral messenger RNA (mRNA) for degradation, as well as indirectly attenuate replication by limiting specific pools of endogenous RNAs. The 3′ degradation machinery (RNA exosome) is emerging as a downstream effector of a diverse array of vRNA sensors. This review discusses our current understanding of the roles of the RNA decay machinery in controlling viral infection. PMID:28054965

  2. The clinically approved antiviral drug sofosbuvir inhibits Zika virus replication

    PubMed Central

    Sacramento, Carolina Q.; de Melo, Gabrielle R.; de Freitas, Caroline S.; Rocha, Natasha; Hoelz, Lucas Villas Bôas; Miranda, Milene; Fintelman-Rodrigues, Natalia; Marttorelli, Andressa; Ferreira, André C.; Barbosa-Lima, Giselle; Abrantes, Juliana L.; Vieira, Yasmine Rangel; Bastos, Mônica M.; de Mello Volotão, Eduardo; Nunes, Estevão Portela; Tschoeke, Diogo A.; Leomil, Luciana; Loiola, Erick Correia; Trindade, Pablo; Rehen, Stevens K.; Bozza, Fernando A.; Bozza, Patrícia T.; Boechat, Nubia; Thompson, Fabiano L.; de Filippis, Ana M. B.; Brüning, Karin; Souza, Thiago Moreno L.

    2017-01-01

    Zika virus (ZIKV) is a member of the Flaviviridae family, along with other agents of clinical significance such as dengue (DENV) and hepatitis C (HCV) viruses. Since ZIKV causes neurological disorders during fetal development and in adulthood, antiviral drugs are necessary. Sofosbuvir is clinically approved for use against HCV and targets the protein that is most conserved among the members of the Flaviviridae family, the viral RNA polymerase. Indeed, we found that sofosbuvir inhibits ZIKV RNA polymerase, targeting conserved amino acid residues. Sofosbuvir inhibited ZIKV replication in different cellular systems, such as hepatoma (Huh-7) cells, neuroblastoma (SH-Sy5y) cells, neural stem cells (NSC) and brain organoids. In addition to the direct inhibition of the viral RNA polymerase, we observed that sofosbuvir also induced an increase in A-to-G mutations in the viral genome. Together, our data highlight a potential secondary use of sofosbuvir, an anti-HCV drug, against ZIKV. PMID:28098253

  3. The clinically approved antiviral drug sofosbuvir inhibits Zika virus replication.

    PubMed

    Sacramento, Carolina Q; de Melo, Gabrielle R; de Freitas, Caroline S; Rocha, Natasha; Hoelz, Lucas Villas Bôas; Miranda, Milene; Fintelman-Rodrigues, Natalia; Marttorelli, Andressa; Ferreira, André C; Barbosa-Lima, Giselle; Abrantes, Juliana L; Vieira, Yasmine Rangel; Bastos, Mônica M; de Mello Volotão, Eduardo; Nunes, Estevão Portela; Tschoeke, Diogo A; Leomil, Luciana; Loiola, Erick Correia; Trindade, Pablo; Rehen, Stevens K; Bozza, Fernando A; Bozza, Patrícia T; Boechat, Nubia; Thompson, Fabiano L; de Filippis, Ana M B; Brüning, Karin; Souza, Thiago Moreno L

    2017-01-18

    Zika virus (ZIKV) is a member of the Flaviviridae family, along with other agents of clinical significance such as dengue (DENV) and hepatitis C (HCV) viruses. Since ZIKV causes neurological disorders during fetal development and in adulthood, antiviral drugs are necessary. Sofosbuvir is clinically approved for use against HCV and targets the protein that is most conserved among the members of the Flaviviridae family, the viral RNA polymerase. Indeed, we found that sofosbuvir inhibits ZIKV RNA polymerase, targeting conserved amino acid residues. Sofosbuvir inhibited ZIKV replication in different cellular systems, such as hepatoma (Huh-7) cells, neuroblastoma (SH-Sy5y) cells, neural stem cells (NSC) and brain organoids. In addition to the direct inhibition of the viral RNA polymerase, we observed that sofosbuvir also induced an increase in A-to-G mutations in the viral genome. Together, our data highlight a potential secondary use of sofosbuvir, an anti-HCV drug, against ZIKV.

  4. DOCK8 regulates lymphocyte shape integrity for skin antiviral immunity

    PubMed Central

    Zhang, Qian; Dove, Christopher G.; Hor, Jyh Liang; Murdock, Heardley M.; Strauss-Albee, Dara M.; Garcia, Jordan A.; Mandl, Judith N.; Grodick, Rachael A.; Jing, Huie; Chandler-Brown, Devon B.; Lenardo, Timothy E.; Crawford, Greg; Matthews, Helen F.; Freeman, Alexandra F.; Cornall, Richard J.; Germain, Ronald N.

    2014-01-01

    DOCK8 mutations result in an inherited combined immunodeficiency characterized by increased susceptibility to skin and other infections. We show that when DOCK8-deficient T and NK cells migrate through confined spaces, they develop cell shape and nuclear deformation abnormalities that do not impair chemotaxis but contribute to a distinct form of catastrophic cell death we term cytothripsis. Such defects arise during lymphocyte migration in collagen-dense tissues when DOCK8, through CDC42 and p21-activated kinase (PAK), is unavailable to coordinate cytoskeletal structures. Cytothripsis of DOCK8-deficient cells prevents the generation of long-lived skin-resident memory CD8 T cells, which in turn impairs control of herpesvirus skin infections. Our results establish that DOCK8-regulated shape integrity of lymphocytes prevents cytothripsis and promotes antiviral immunity in the skin. PMID:25422492

  5. Identification and Analysis of Antiviral Compounds Against Poliovirus.

    PubMed

    Leyssen, Pieter; Franco, David; Tijsma, Aloys; Lacroix, Céline; De Palma, Armando; Neyts, Johan

    2016-01-01

    The Global Polio Eradication Initiative, launched in 1988, had as its goal the eradication of polio worldwide by the year 2000 through large-scale vaccinations campaigns with the live attenuated oral PV vaccine (OPV) (Griffiths et al., Biologicals 34:73-74, 2006). Despite substantial progress, polio remains endemic in several countries and new imported cases are reported on a regular basis ( http://www.polioeradication.org/casecount.asp ).It was recognized by the poliovirus research community that developing antivirals against poliovirus would be invaluable in the post-OPV era. Here, we describe three methods essential for the identification of selective inhibitors of poliovirus replication and for determining their mode of action by time-of-drug-addition studies as well as by the isolation of compound-resistant poliovirus variants.

  6. Monitoring the antiviral effect of alpha interferon on individual cells.

    PubMed

    Kim, Chon Saeng; Jung, Jong Ha; Wakita, Takaji; Yoon, Seung Kew; Jang, Sung Key

    2007-08-01

    An infectious hepatitis C virus (HCV) cDNA clone (JFH1) was generated recently. However, quantitative analysis of HCV infection and observation of infected cells have proved to be difficult because the yield of HCV in cell cultures is fairly low. We generated infectious HCV clones containing the convenient reporters green fluorescent protein (GFP) and Renilla luciferase in the NS5a-coding sequence. The new viruses responded to antiviral agents in a dose-dependent manner. Responses of individual cells containing HCV to alpha interferon (IFN-alpha) were monitored using GFP-tagged HCV and time-lapse confocal microscopy. Marked variations in the response to IFN-alpha were observed among HCV-containing cells.

  7. Antiviral activities of hybrids of two major human leukocyte interferons.

    PubMed Central

    Weck, P K; Apperson, S; Stebbing, N; Gray, P W; Leung, D; Shepard, H M; Goeddel, D V

    1981-01-01

    Four hybrid human leukocyte interferon (LeIF or IFN-alpha) genes have been constructed by in vitro recombination of LeIF-A (IFN-alpha 2) and LeIF-D (IFN-alpha 1) genes at common restriction endonuclease sites located within their coding regions. These hybrid genes have been expressed in E. coli under trp promoter control. The interferons produced [LeIF-AD (BglII), -AD (PvuII), -DA (BglII), -DA (PvuII)] have antiviral properties distinct from the parental molecules LeIF-A and -D, varying considerably in their abilities to inhibit plaque formation by different viruses in a range of mammalian cells. All six of the cloned LeIFs exhibit the heat stability, pH 2 stability and antigenic specificity of natural leukocyte interferons. PMID:6171779

  8. Optimal Antiviral Switching to Minimize Resistance Risk in HIV Therapy

    PubMed Central

    Luo, Rutao; Piovoso, Michael J.; Martinez-Picado, Javier; Zurakowski, Ryan

    2011-01-01

    The development of resistant strains of HIV is the most significant barrier to effective long-term treatment of HIV infection. The most common causes of resistance development are patient noncompliance and pre-existence of resistant strains. In this paper, methods of antiviral regimen switching are developed that minimize the risk of pre-existing resistant virus emerging during therapy switches necessitated by virological failure. Two distinct cases are considered; a single previous virological failure and multiple virological failures. These methods use optimal control approaches on experimentally verified mathematical models of HIV strain competition and statistical models of resistance risk. It is shown that, theoretically, order-of-magnitude reduction in risk can be achieved, and multiple previous virological failures enable greater success of these methods in reducing the risk of subsequent treatment failures. PMID:22073250

  9. An Antiviral Defense Role of AGO2 in Plants

    PubMed Central

    Harvey, Jagger J. W.; Lewsey, Mathew G.; Patel, Kanu; Westwood, Jack; Heimstädt, Susanne; Carr, John P.; Baulcombe, David C.

    2011-01-01

    Background Argonaute (AGO) proteins bind to small-interfering (si)RNAs and micro (mi)RNAs to target RNA silencing against viruses, transgenes and in regulation of mRNAs. Plants encode multiple AGO proteins but, in Arabidopsis, only AGO1 is known to have an antiviral role. Methodology/Principal Findings To uncover the roles of specific AGOs in limiting virus accumulation we inoculated turnip crinkle virus (TCV) to Arabidopsis plants that were mutant for each of the ten AGO genes. The viral symptoms on most of the plants were the same as on wild type plants although the ago2 mutants were markedly hyper-susceptible to this virus. ago2 plants were also hyper-susceptible to cucumber mosaic virus (CMV), confirming that the antiviral role of AGO2 is not specific to a single virus. For both viruses, this phenotype was associated with transient increase in virus accumulation. In wild type plants the AGO2 protein was induced by TCV and CMV infection. Conclusions/Significance Based on these results we propose that there are multiple layers to RNA-mediated defense and counter-defense in the interactions between plants and their viruses. AGO1 represents a first layer. With some viruses, including TCV and CMV, this layer is overcome by viral suppressors of silencing that can target AGO1 and a second layer involving AGO2 limits virus accumulation. The second layer is activated when the first layer is suppressed because AGO2 is repressed by AGO1 via miR403. The activation of the second layer is therefore a direct consequence of the loss of the first layer of defense. PMID:21305057

  10. Curious discoveries in antiviral drug development: the role of serendipity.

    PubMed

    De Clercq, Erik

    2015-07-01

    Antiviral drug development has often followed a curious meandrous route, guided by serendipity rather than rationality. This will be illustrated by ten examples. The polyanionic compounds (i) polyethylene alanine (PEA) and (ii) suramin were designed as an antiviral agent (PEA) or known as an antitrypanosomal agent (suramin), before they emerged as, respectively, a depilatory agent, or reverse transcriptase inhibitor. The 2',3'-dideoxynucleosides (ddNs analogues) (iii) have been (and are still) used in the "Sanger" DNA sequencing technique, although they are now commercialized as nucleoside reverse transcriptase inhibitors (NRTIs) in the treatment of HIV infections. (E)-5-(2-Bromovinyl)-2'-deoxyuridine (iv) was discovered as a selective anti-herpes simplex virus compound and is now primarily used for the treatment of varicella-zoster virus infections. The prototype of the acyclic nucleoside phosphonates (ANPs), (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA], (v) was never commercialized, although it gave rise to several marketed products (cidofovir, adefovir, and tenofovir). 1-[2-(Hydroxyethoxy)methyl]-6-(phenylthio)thymine (vi) and TIBO (tetrahydroimidazo[4,5,1-jk][1,4-benzodiazepin-2(1H)]-one and -thione) (vii) paved the way to a number of compounds (i.e., nevirapine, delavirdine, etravirine, and rilpivirine), which are now collectively called non-NRTIs. The bicyclam AMD3100 (viii) was originally described as an anti-HIV agent before it became later marketed as a stem cell mobilizer. The S-adenosylhomocysteine hydrolase inhibitors (ix), while active against a broad range of (-)RNA viruses and poxviruses may be particularly effective against Ebola virus, and for (x) the O-ANP derivatives, the potential application range encompasses virtually all DNA viruses.

  11. Sensitive radioimmunoassay for the broad-spectrum antiviral agent ribavirin.

    PubMed

    Austin, R K; Trefts, P E; Hintz, M; Connor, J D; Kagnoff, M F

    1983-11-01

    Ribavirin, 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxyamide (Virazole; Viratek, Inc., Covina, Calif.), has a broad spectrum of antiviral activity. However, the study of the absorption, metabolism, and excretion of this compound has been limited by the lack of an appropriate assay for ribavirin and its metabolites. Since ribavirin has definite potential for therapeutic use, we developed a radioimmunoassay to measure ribavirin levels in clinical specimens. To prepare an effective immunogen, ribavirin was monosuccinylated and coupled to ovalbumin. The competitive binding radioimmunoassay, in which tritium-labeled ribavirin and rabbit antiribavirin serum were used, was quantitative for ribavirin at concentrations of 1 pmol/100 microliter in urine or plasma samples. The rabbit antibody cross-reacted with the major metabolite of ribavirin, 1,2,4-triazole-3-carboxamide, at a low level (2 to 5%) which did not interfere with ribavirin binding until concentrations of 1,2,4-triazole-3-carboxamide 10- to 100-fold higher than ribavirin were present in mock samples, a condition not present in biological specimens. We used the ribavirin radioimmunoassay to determine the ribavirin concentration in mouse plasma after intraperitoneal administration, in the sera of adults from Sierra Leone after oral or intravenous administration for treatment of suspected Lassa fever, and in the sera of children in the United States after small-particle aerosol administration. Our experience with the radioimmunoassay indicates that it is sensitive, accurate, and reproducible. The assay will permit studies leading to a better understanding of the pharmacology and pharmacokinetics of this potentially useful antiviral drug.

  12. Antiviral Natural Products Against Chronic Hepatitis B: Recent Developments.

    PubMed

    Parvez, Mohammad K; Arbab, Ahmed H; Al-Dosari, Mohammed S; Al-Rehaily, Adnan J

    2016-01-01

    Hepatitis B virus (HBV) is inherently a hepatotropic virus that causes acute and chronic hepatitis in about one-third of world population. Of the estimated 360 million chronically infected individuals, more than one million die of liver cirrhosis, fulminant liver failure or hepatocellular carcinoma (HCC) every year. Though there is an effective vaccine available, failure to protection because of vaccine-escape viral mutants in some population is also reported. Moreover, all the currently approved antiviral drugs have their limitations, too. Interferon (IFN-α) has limited efficacy and a high incidence of adverse side-effects in a proportion of chronic patients. Nucleos(t)ide analogs like, lamivudine, adefovir, tenofovir and entecavir are very effective in treating chronic hepatitis B (CHB), but long-term therapy eventually leads to drug-resistance. As an alternative approach, natural or plant products have provided promising therapeutics in modern pharma industry. Owing to their characteristics of high chemical diversity and biochemical specificity, natural products offer great promises as potentially effective antiviral drugs. A broad spectrum of phytochemicals including flavonoids (e.g., Vogonin), terpenes (e.g., Artemisinin), alkaloids (e.g., Oxymatrine), polyphenolics (e.g., geraniin), saponins (e.g., Astragaloside IV) and lignans (e.g., Helioxanthin) has been isolated and investigated for anti-HBV activities in vitro as well as in vivo. Nevertheless, these promising compounds have different and overlapping mechanisms of action by either inhibiting viral antigens secretion or suppression of DNA replication. The present article reviews the recent developments in anti-HBV natural products.

  13. General pharmacology of the new antiviral agent SK 1899.

    PubMed

    Ryu, K H; Rhee, H I; Jung, I; Kim, T S; Lee, S J; Im, G J; Lee, N; Ryu, D H; Kim, Y W; Kim, J J; Chang, K; Lee, B H; Shin, H S; Kim, E J; Kim, K H; Kim, D K

    2000-04-01

    The general pharmacological properties of 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)purine (CAS 247081-81-8, SK 1899), a new potential antiviral agent, were investigated in mice, rats, guinea pigs, rabbits, and dogs. The oral administration of 50, 150, and 500 mg/kg of SK 1899 had no effects on the central nervous system except that it slightly increased the spontaneous locomotor activity in mice at a dose of 500 mg/kg. SK 1899 did not disturb either the spontaneous motility or contractor-induced contraction of the isolated organs such as guinea pig ileum, rat uterus, guinea pig vas deferens, and guinea pig trachea at concentrations up to 10(-4) mol/l. It slightly increased the contractile force in the isolated guinea pig atrium at a concentration of 10(-4) mol/l. Following intravenous infusion of 5, 15, and 50 mg/kg of SK 1899 to anesthetized dogs, it did not change the mean arterial pressure, heart rate, left ventricular systolic pressure (LVSP), and respiratory rate, while it slightly increased the left ventricular positive dP/dtmax (LV + dP/dtmax) at a dose of 50 mg/kg. SK 1899 did not induce any significant changes in the intestinal charcoal meal transit in mice, basal gastric juice secretion in rats, and renal function in rats. It did not affect the blood coagulation system and phenolsulfonphthalein secretion in rats. These findings suggest that SK 1899 has a very low potential to induce any adverse pharmacological effects at the doses showing antiviral activity.

  14. Evasion of the interferon-mediated antiviral response by filoviruses.

    PubMed

    Cárdenas, Washington B

    2010-01-01

    The members of the filoviruses are recognized as some of the most lethal viruses affecting human and non-human primates. The only two genera of the Filoviridae family, Marburg virus (MARV) and Ebola virus (EBOV), comprise the main etiologic agents of severe hemorrhagic fever outbreaks in central Africa, with case fatality rates ranging from 25 to 90%. Fatal outcomes have been associated with a late and dysregulated immune response to infection, very likely due to the virus targeting key host immune cells, such as macrophages and dendritic cells (DCs) that are necessary to mediate effective innate and adaptive immune responses. Despite major progress in the development of vaccine candidates for filovirus infections, a licensed vaccine or therapy for human use is still not available. During the last ten years, important progress has been made in understanding the molecular mechanisms of filovirus pathogenesis. Several lines of evidence implicate the impairment of the host interferon (IFN) antiviral innate immune response by MARV or EBOV as an important determinant of virulence. In vitro and in vivo experimental infections with recombinant Zaire Ebola virus (ZEBOV), the best characterized filovirus, demonstrated that the viral protein VP35 plays a key role in inhibiting the production of IFN-α/β. Further, the action of VP35 is synergized by the inhibition of cellular responses to IFN-α/β by the minor matrix viral protein VP24. The dual action of these viral proteins may contribute to an efficient initial virus replication and dissemination in the host. Noticeably, the analogous function of these viral proteins in MARV has not been reported. Because the IFN response is a major component of the innate immune response to virus infection, this chapter reviews recent findings on the molecular mechanisms of IFN-mediated antiviral evasion by filovirus infection.

  15. Predictive factors associated with hepatitis C antiviral therapy response

    PubMed Central

    Cavalcante, Lourianne Nascimento; Lyra, André Castro

    2015-01-01

    Hepatitis C virus (HCV) infection may lead to significant liver injury, and viral, environmental, host, immunologic and genetic factors may contribute to the differences in the disease expression and treatment response. In the early 2000s, dual therapy using a combination of pegylated interferon plus ribavirin (PR) became the standard of care for HCV treatment. In this PR era, predictive factors of therapy response related to virus and host have been identified. In 2010/2011, therapeutic regimens for HCV genotype 1 patients were modified, and the addition of NS3/4a protease inhibitors (boceprevir or telaprevir) to dual therapy increased the effectiveness and chances of sustained virologic response (SVR). Nevertheless, the first-generation triple therapy is associated with many adverse events, some of which are serious and associated with death, particularly in cirrhotic patients. This led to the need to identify viral and host predictive factors that might influence the SVR rate to triple therapy and avoid unnecessary exposure to these drugs. Over the past four years, hepatitis C treatment has been rapidly changing with the development of new therapies and other developments. Currently, with the more recent generations of pangenotipic antiviral therapies, there have been higher sustained virologic rates, and prognostic factors may not have the same importance and strength as before. Nonetheless, some variables may still be consistent with the low rates of non-response with regimens that include sofosbuvir, daclatasvir and ledipasvir. In this manuscript, we review the predictive factors of therapy response across the different treatment regimens over the last decade including the new antiviral drugs. PMID:26140082

  16. Clinical responders to antiviral therapy of chronic HCV infection show elevated antiviral CD4+ and CD8+ T-cell responses.

    PubMed

    Pillai, Vinodh; Lee, William M; Thiele, Dwain L; Karandikar, Nitin J

    2007-05-01

    Chronic hepatitis C virus (HCV) infection is characterized by attenuated antiviral T-cell responses, making their detection and characterization a technological challenge. The role and the dynamics of antiviral T-cell responses during antiviral therapy are incompletely understood. To assess HCV-specific T-cell responses during antiviral therapy of genotype-1-infected patients, we adopted a flow cytometric approach to comprehensively evaluate virus-specific CD4+ and CD8+ T-cell proliferative responses against pools of genotype- and subtype-specific serial, overlapping peptides spanning the entire virus. Studies in cross-sectional cohorts of treatment-naïve (TN) patients , early and sustained clinical virological responders (EVRs and SVRs) or clinical nonresponders (NRs) showed that this proliferative assay had significantly greater sensitivity in detecting HCV-specific responses, compared with ex vivo cytokine flow cytometry. At the same time, it could be used to detect and quantify both CD4+ and CD8+ responses simultaneously. EVRs and SVRs showed significantly more HCV-specific CD4+ and CD8+ responses, compared with either TN patients or NRs. This corresponded to a higher magnitude of responses as well as a greater breadth of reactivity with higher responses against the core/E1, NS3, NS4 and NS5b regions of the virus. Interestingly, both clinical responders and NRs showed higher cytomegalovirus-specific CD4+ responses, compared with TN patients. These results demonstrate an association between clinically successful antiviral therapy and enhanced magnitude and breadth of antiviral responses. Moreover, the study demonstrates the clinical relevance of this flow cytometric proliferation assay system, in combination with an unbiased library of viral peptides, in evaluating the biology of antiviral T-cell responses during infection and therapy.

  17. Dysbiosis-induced IL-33 contributes to impaired antiviral immunity in the genital mucosa.

    PubMed

    Oh, Ji Eun; Kim, Byoung-Chan; Chang, Dong-Ho; Kwon, Meehyang; Lee, Sun Young; Kang, Dukjin; Kim, Jin Young; Hwang, Inhwa; Yu, Je-Wook; Nakae, Susumu; Lee, Heung Kyu

    2016-02-09

    Commensal microbiota are well known to play an important role in antiviral immunity by providing immune inductive signals; however, the consequence of dysbiosis on antiviral immunity remains unclear. We demonstrate that dysbiosis caused by oral antibiotic treatment directly impairs antiviral immunity following viral infection of the vaginal mucosa. Antibiotic-treated mice succumbed to mucosal herpes simplex virus type 2 infection more rapidly than water-fed mice, and also showed delayed viral clearance at the site of infection. However, innate immune responses, including type I IFN and proinflammatory cytokine production at infection sites, as well as induction of virus-specific CD4 and CD8 T-cell responses in draining lymph nodes, were not impaired in antibiotic-treated mice. By screening the factors controlling antiviral immunity, we found that IL-33, an alarmin released in response to tissue damage, was secreted from vaginal epithelium after the depletion of commensal microbiota. This cytokine suppresses local antiviral immunity by blocking the migration of effector T cells to the vaginal tissue, thereby inhibiting the production of IFN-γ, a critical cytokine for antiviral defense, at local infection sites. These findings provide insight into the mechanisms of homeostasis maintained by commensal bacteria, and reveal a deleterious consequence of dysbiosis in antiviral immune defense.

  18. Antiviral activity of ginsenosides against coxsackievirus B3, enterovirus 71, and human rhinovirus 3

    PubMed Central

    Song, Jae-Hyoung; Choi, Hwa-Jung; Song, Hyuk-Hwan; Hong, Eun-Hye; Lee, Bo-Ra; Oh, Sei-Ryang; Choi, Kwangman; Yeo, Sang-Gu; Lee, Yong-Pyo; Cho, Sungchan; Ko, Hyun-Jeong

    2014-01-01

    Background Ginsenosides are the major components responsible for the biochemical and pharmacological actions of ginseng, and have been shown to have various biological activities. In this study, we investigated the antiviral activities of seven ginsenosides [protopanaxatriol (PT) type: Re, Rf, and Rg2; protopanaxadiol (PD) type: Rb1, Rb2, Rc, and Rd)] against coxsackievirus B3 (CVB3), enterovirus 71 (EV71), and human rhinovirus 3 (HRV3). Methods Assays of antiviral activity and cytotoxicity were evaluated by the sulforhodamine B method using the cytopathic effect (CPE) reduction assay. Results The antiviral assays demonstrated that, of the seven ginsenosides, the PT-type ginsenosides (Re, Rf, and Rg2) possess significant antiviral activities against CVB3 and HRV3 at a concentration of 100 μg/mL. Among the PT-type ginsenosides, only ginsenoside Rg2 showed significant anti-EV71 activity with no cytotoxicity to cells at 100 μg/mL. The PD-type ginsenosides (Rb1, Rb2, Rc, and Rd), by contrast, did not show any significant antiviral activity against CVB3, EV71, and HRV3, and exhibited cytotoxic effects to virus-infected cells. Notably, the antiviral efficacies of PT-type ginsenosides were comparable to those of ribavirin, a commonly used antiviral drug. Conclusion Collectively, our findings suggest that the ginsenosides Re, Rf, and Rg2 have the potential to be effective in the treatment of CVB3, EV71, and HRV3 infection. PMID:25378991

  19. Antiviral activity of silver nanoparticle/chitosan composites against H1N1 influenza A virus

    NASA Astrophysics Data System (ADS)

    Mori, Yasutaka; Ono, Takeshi; Miyahira, Yasushi; Nguyen, Vinh Quang; Matsui, Takemi; Ishihara, Masayuki

    2013-02-01

    Silver nanoparticle (Ag NP)/chitosan (Ch) composites with antiviral activity against H1N1 influenza A virus were prepared. The Ag NP/Ch composites were obtained as yellow or brown floc-like powders following reaction at room temperature in aqueous medium. Ag NPs (3.5, 6.5, and 12.9 nm average diameters) were embedded into the chitosan matrix without aggregation or size alternation. The antiviral activity of the Ag NP/Ch composites was evaluated by comparing the TCID50 ratio of viral suspensions treated with the composites to untreated suspensions. For all sizes of Ag NPs tested, antiviral activity against H1N1 influenza A virus increased as the concentration of Ag NPs increased; chitosan alone exhibited no antiviral activity. Size dependence of the Ag NPs on antiviral activity was also observed: antiviral activity was generally stronger with smaller Ag NPs in the composites. These results indicate that Ag NP/Ch composites interacting with viruses exhibit antiviral activity.

  20. Surfactant-Modified Nanoclay Exhibits an Antiviral Activity with High Potency and Broad Spectrum

    PubMed Central

    Liang, Jian-Jong; Wei, Jiun-Chiou; Lee, Yi-Ling; Lin, Jiang-Jen

    2014-01-01

    ABSTRACT Nanomaterials have the characteristics associated with high surface-to-volume ratios and have been explored for their antiviral activity. Despite some success, cytotoxicity has been an issue in nanomaterial-based antiviral strategies. We previously developed a novel method to fully exfoliate montmorillonite clay to generate the most fundamental units of nanoscale silicate platelet (NSP). We further modified NSP by capping with various surfactants and found that the surfactant-modified NSP (NSQ) was less cytotoxic. In this study, we tested the antiviral potentials of a series of natural-clay-derived nanomaterials. Among the derivatives, NSP modified with anionic sodium dodecyl sulfate (NSQc), but not the pristine clay, unmodified NSP, a silver nanoparticle-NSP hybrid, NSP modified with cationic n-octadecanylamine hydrochloride salt, or NSP modified with nonionic Triton X-100, significantly suppressed the plaque-forming ability of Japanese encephalitis virus (JEV) at noncytotoxic concentrations. NSQc also blocked infection with dengue virus (DEN) and influenza A virus. Regarding the antiviral mechanism, NSQc interfered with viral binding through electrostatic interaction, since its antiviral activity can be neutralized by Polybrene, a cationic polymer. Furthermore, NSQc reduced the lethality of JEV and DEN infection in mouse challenge models. Thus, the surfactant-modified exfoliated nanoclay NSQc may be a novel nanomaterial with broad and potent antiviral activity. IMPORTANCE Nanomaterials have being investigated as antimicrobial agents, yet their antiviral potential is overshadowed by their cytotoxicity. By using a novel method, we fully exfoliated montmorillonite clay to generate the most fundamental units of nanoscale silicate platelet (NSP). Here, we show that the surfactant-modified NSP (NSQ) is less cytotoxic and that NSQc (NSP modified with sodium dodecyl sulfate) could potently block infection by dengue virus (DEN), Japanese encephalitis virus (JEV

  1. The antiviral effect of human interferon alpha is dependent on phosphoinositide-derived messengers.

    PubMed

    Cernescu, C; Constantinescu, S N; Baltă, F; Popescu, L M

    1988-01-01

    Neomycin the putative blocker of membrane polyphosphoinositide hydrolysis, inhibited the antiviral activity of human interferon alpha, when tested on human quiescent fibroblasts challenged with vesicular stomatitis virus. The anti-interferon effect of neomycin could be correlated in terms of dose dependence for both neomycin (0.05-1 mM) and interferon (100-5,000 IU/ml). The results suggest that the antiviral activity of interferon alpha depends on diacylglycerol formation. Indeed, the synthetic diacylglycerol (50 microM) was as effective as 100 IU/ml interferon in inducing the antiviral state.

  2. [Effectiveness and safety of antiviral therapy of military personnel suffering from chronic hepatitis C].

    PubMed

    Zhdanov, K V; Gusev, D A; Kozlov, K V; Shishkin, M K; Sukachev, V S; Shakhmanov, D M; Zhabrov, S S

    2015-04-01

    In order to evaluate effectiveness and safety of antiviral therapy schemes examined and treated 191 patients with chronic bepatitis C were assigned standard interferon and ribavirin, pegslated interferon and ribavirin, the total duration of the course coput 24-48 weeks. Based on clinical and laboratory parameters evaluated the safety of antiviral therapy. Formation of sustainable viral response, depending on the genotype observed, was given at 58,9-70%.of patients. In case of insufficient. antiviral therapy was prescribed a second course that will improve the effectiveness of treatment to 90-95%. Correction of adverse events was held lower dosages of interferon and/or ribavirin.

  3. Defense and counterdefense in the RNAi-based antiviral immune system in insects.

    PubMed

    van Mierlo, Joël T; van Cleef, Koen W R; van Rij, Ronald P

    2011-01-01

    RNA interference (RNAi) is an important pathway to combat virus infections in insects and plants. Hallmarks of antiviral RNAi in these organisms are: (1) an increase in virus replication after inactivation of major actors in the RNAi pathway, (2) production of virus-derived small interfering RNAs (v-siRNAs), and (3) suppression of RNAi by dedicated viral proteins. In this chapter, we will review the mechanism of RNAi in insects, its function as an antiviral immune system, viral small RNA profiles, and viral counterdefense strategies. We will also consider alternative, inducible antiviral immune responses.

  4. Antiviral therapy in compensated and decompensated cirrhotic patients with chronic HCV infection.

    PubMed

    Iacobellis, Angelo; Andriulli, Angelo

    2009-08-01

    Liver cirrhosis secondary to HCV infection is a chronic disorder that carries high morbidity and mortality. Approved antiviral treatment for this condition at present includes peginterferon in combination with ribavirin. Treatment is only recommended for a well-compensated liver cirrhosis, whereas antiviral therapy is commonly not implemented in cirrhotics with signs of liver decompensation, over the concern that the use of peginterferon and ribavirin might expose patients to severe treatment-related side effects. This review focuses on data available to support both efficacy and safety of antiviral therapy in both compensated and decompensated cirrhotic patients.

  5. The antiviral and antimicrobial activities of licorice, a widely-used Chinese herb

    PubMed Central

    Wang, Liqiang; Yang, Rui; Yuan, Bochuan; Liu, Ying; Liu, Chunsheng

    2015-01-01

    Licorice is a common herb which has been used in traditional Chinese medicine for centuries. More than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these metabolites possess many pharmacological activities, such as antiviral, antimicrobial, anti-inflammatory, antitumor and other activities. This paper provides a summary of the antiviral and antimicrobial activities of licorice. The active components and the possible mechanisms for these activities are summarized in detail. This review will be helpful for the further studies of licorice for its potential therapeutic effects as an antiviral or an antimicrobial agent. PMID:26579460

  6. Rapid induction and persistence of paracrine-induced cellular antiviral states arrest viral infection spread in A549 cells

    PubMed Central

    Voigt, Emily A; Swick, Adam; Yin, John

    2016-01-01

    The virus/host interaction is a complex interplay between pro- and anti-viral factors that ultimately determines the spread or halt of virus infections in tissues. This interplay develops over multiple rounds of infection. The purpose of this study was to determine how cellular-level processes combine to impact the spatial spread of infection. We measured the kinetics of virus replication (VSV), antiviral paracrine signal upregulation and secretion, spatial spread of virus and paracrine antiviral signaling, and inhibition of virus production in antiviral-exposed A549 human lung epithelial cells. We found that initially infected cells released antiviral signals 4-to-7 hours following production of virus. However, the subsequent rapid dissemination of signal and fast induction of a robust and persistent antiviral state ultimately led to a suppression of infection spread. This work shows how cellular responses to infection and activation of antiviral responses can integrate to ultimately control infection spread across host cell populations. PMID:27254596

  7. Progress in the development of poliovirus antiviral agents and their essential role in reducing risks that threaten eradication.

    PubMed

    McKinlay, Mark A; Collett, Marc S; Hincks, Jeffrey R; Oberste, M Steven; Pallansch, Mark A; Okayasu, Hiromasa; Sutter, Roland W; Modlin, John F; Dowdle, Walter R

    2014-11-01

    Chronic prolonged excretion of vaccine-derived polioviruses by immunodeficient persons (iVDPV) presents a personal risk of poliomyelitis to the patient as well as a programmatic risk of delayed global eradication. Poliovirus antiviral drugs offer the only mitigation of these risks. Antiviral agents may also have a potential role in the management of accidental exposures and in certain outbreak scenarios. Efforts to discover and develop poliovirus antiviral agents have been ongoing in earnest since the formation in 2007 of the Poliovirus Antivirals Initiative. The most advanced antiviral, pocapavir (V-073), is a capsid inhibitor that has recently demonstrated activity in an oral poliovirus vaccine human challenge model. Additional antiviral candidates with differing mechanisms of action continue to be profiled and evaluated preclinically with the goal of having 2 antivirals available for use in combination to treat iVDPV excreters.

  8. Topology of the disulfide bonds in the antiviral lectin scytovirin

    PubMed Central

    Moulaei, Tinoush; Stuchlik, Olga; Reed, Matthew; Yuan, Weirong; Pohl, Jan; Lu, Wuyuan; Haugh-Krumpe, Lauren; O'Keefe, Barry R; Wlodawer, Alexander

    2010-01-01

    The antiviral lectin scytovirin (SVN) contains a total of five disulfide bonds in two structurally similar domains. Previous reports provided contradictory results on the disulfide pairing in each individual domain, and we have now re-examined the disulfide topology. N-terminal sequencing and mass spectrometry were used to analyze proteolytic fragments of native SVN obtained at acidic pH, yielding the assignment as Cys7–Cys55, Cys20–Cys32, Cys26–Cys38, Cys68–Cys80, and Cys74–Cys86. We also analyzed the N-terminal domain of SVN (SD1, residues 1–48) prepared by expression/oxidative folding of the recombinant protein and by chemical synthesis. The disulfide pairing in the chemically synthesized SD1 was forced into predetermined topologies: SD1A (Cys20–Cys26, Cys32–Cys38) or SD1B (Cys20–Cys32, Cys26–Cys38). The topology of native SVN was found to be in agreement with the SD1B and the one determined for the recombinant SD1 domain. Although the two synthetic forms of SD1 were distinct when subjected to chromatography, their antiviral properties were indistinguishable, having low nM activity against HIV. Tryptic fragments, the “cystine clusters” [Cys20–Cys32/Cys26–Cys38; SD1] and [Cys68–Cys80/Cys74–C-86; SD2], were found to undergo rapid disulfide interchange at pH 8. This interchange resulted in accumulation of artifactual fragments in alkaline pH digests that are structurally unrelated to the original topology, providing a rational explanation for the differences between the topology reported herein and the one reported earlier (Bokesh et al., Biochemistry 2003;42:2578–2584). Our observations emphasize the fact that proteins such as SVN, with disulfide bonds in close proximity, require considerable precautions when being fragmented for the purpose of disulfide assignment. PMID:20572021

  9. Successful Eradication of Hepatitis C Virus by Interferon-Free Regimens in Two Patients with Advanced Liver Fibrosis following Kidney Transplantation

    PubMed Central

    Sasaki, Reina; Kanda, Tatsuo; Yasui, Shin; Haga, Yuki; Nakamura, Masato; Yamato, Mutsumi; Wu, Shuang; Nakamoto, Shingo; Arai, Makoto; Mikami, Shigeru; Miyauchi, Hideaki; Matsubara, Hisahiro; Yokosuka, Osamu

    2016-01-01

    Hepatitis C virus (HCV) infection leads to acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Following kidney transplantation, HCV increases the risk of graft loss and patient mortality compared with uninfected patients. The achievement of a sustained virological response with antiviral therapy improves survival and diminishes the risk of hepatic decompensation in HCV patients after a kidney transplant. It has been reported that direct-acting antivirals (DAAs) are relatively safe and highly effective for the eradication of HCV in patients who are liver transplant recipients. In the present study, we investigated HCV eradication via interferon-free therapies with DAAs in two HCV patients with advanced liver fibrosis following renal transplantation. In both cases, the interferon-free regimens with DAAs were effective in eradicating HCV in the patients after kidney transplantation. No adverse events caused by interferon were identified with the exception of anemia. Interferon-free regimens with DAAs for recurrent HCV in patients following kidney transplantation are relatively safe and effective. However, attention should be focused on anemia during these treatments. PMID:27462193

  10. Photo-distributed lichenoid eruption secondary to direct anti-viral therapy for hepatitis C.

    PubMed

    Simpson, Cory L; McCausland, Drew; Chu, Emily Y

    2015-10-01

    Novel direct anti-viral agents are emerging as effective treatments for hepatitis C virus (HCV) and provide an alternative to the year-long standard therapy with interferon and ribavirin. However, cutaneous side effects from these new medications, including rash, pruritus and photosensitivity, are among the most commonly reported adverse events and have resulted in therapy discontinuation in some cases. Here, we report two cases of a photo-distributed lichenoid eruption that occurred within 1  month of starting anti-viral therapy with simeprevir and sofosbuvir without interferon or ribavirin. This report provides the first histologic description of the cutaneous eruption associated with direct anti-viral therapy for HCV and highlights the importance of recognizing and treating the often intolerable dermatologic side effects of these novel medications, the incidence of which is likely to increase as direct anti-viral agents may become the standard of care for HCV.

  11. TRIMmunity: The roles of the TRIM E3-ubiquitin ligase family in innate antiviral immunity

    PubMed Central

    Rajsbaum, Ricardo; García-Sastre, Adolfo; Versteeg, Gijs A.

    2014-01-01

    Tripartite motif (TRIM) proteins have been implicated in multiple cellular functions, including antiviral activity. Research efforts so far indicate that the antiviral activity of TRIMs relies, for the most part, on their function as E3-ubiquitin ligases. A substantial number of the TRIM-family members have been demonstrated to mediate innate immune cell signal transduction and subsequent cytokine induction. In addition, a subset of TRIMs has been shown to restrict viral replication by directly targeting viral proteins. Although the body of work on the cellular roles of TRIM E3 ubiquitin ligases has rapidly grown over the last years, many aspects of their molecular workings and multi-functionality remain unclear. The antiviral function of many TRIMs seems to be conferred by specific isoforms, sub-cellular localization, and in cell-type specific contexts. Here we review recent findings on TRIM antiviral functions, current limitations and an outlook for future research. PMID:24333484

  12. New Study Shows Clinicians Under-Prescribing Flu Antiviral Drugs and Possibly Overprescribing Antibiotics

    MedlinePlus

    ... Under-Prescribing Flu Antiviral Drugs and Possibly Overprescribing Antibiotics Language: English Español Recommend on Facebook Tweet ... medications. In contrast, clinicians may have overprescribed common antibiotics. The authors of the study concluded that more ...

  13. 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

  14. Antiviral effect of lithium chloride on infection of cells by canine parvovirus.

    PubMed

    Zhou, Pei; Fu, Xinliang; Yan, Zhongshan; Fang, Bo; Huang, San; Fu, Cheng; Hong, Malin; Li, Shoujun

    2015-11-01

    Canine parvovirus type 2 causes significant viral disease in dogs, with high morbidity, high infectivity, and high mortality. Lithium chloride is a potential antiviral drug for viruses. We determined the antiviral effect of Lithium Chloride on canine parvovirus type 2 in feline kidney cells. The viral DNA and proteins of canine parvovirus were suppressed in a dose-dependent manner by lithium chloride. Further investigation verified that viral entry into cells was inhibited in a dose-dependent manner by lithium chloride. These results indicated that lithium chloride could be a potential antiviral drug for curing dogs with canine parvovirus infection. The specific steps of canine parvovirus entry into cells that are affected by lithium chloride and its antiviral effect in vivo should be explored in future studies.

  15. African swine fever virus: current state and future perspectives in vaccine and antiviral research.

    PubMed

    Zakaryan, Hovakim; Revilla, Yolanda

    2016-03-15

    African swine fever (ASF) is among the most significant of swine diseases for which no effective vaccines and antivirals are available. The disease, which is endemic in Africa, was introduced to Trans-Caucasian countries and the Russian Federation in 2007, where it remains prevalent today among domestic pigs and wild boars. Although some measures were implemented, ASF continues to pose a global risk for all countries, and thereby highlighting the importance of vaccine and antiviral research. In this review, an overview of research efforts toward the development of effective vaccines during the past decades is presented. As an alternative to vaccine development, the current state in antiviral research against ASFV is also presented. Finally, future perspectives in vaccine and antiviral research giving emphasis on some strategies that may allow researchers to develop effective countermeasures against ASF are discussed.

  16. 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

  17. TRIMmunity: the roles of the TRIM E3-ubiquitin ligase family in innate antiviral immunity.

    PubMed

    Rajsbaum, Ricardo; García-Sastre, Adolfo; Versteeg, Gijs A

    2014-03-20

    Tripartite motif (TRIM) proteins have been implicated in multiple cellular functions, including antiviral activity. Research efforts so far indicate that the antiviral activity of TRIMs relies, for the most part, on their function as E3-ubiquitin ligases. A substantial number of the TRIM family members have been demonstrated to mediate innate immune cell signal transduction and subsequent cytokine induction. In addition, a subset of TRIMs has been shown to restrict viral replication by directly targeting viral proteins. Although the body of work on the cellular roles of TRIM E3-ubiquitin ligases has rapidly grown over the last years, many aspects of their molecular workings and multi-functionality remain unclear. The antiviral function of many TRIMs seems to be conferred by specific isoforms, by sub-cellular localization and in cell-type-specific contexts. Here we review recent findings on TRIM antiviral functions, current limitations and an outlook for future research.

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

    PubMed Central

    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. PMID:26484353

  19. Myeloid C-Type Lectin Receptors in Viral Recognition and Antiviral Immunity

    PubMed Central

    Monteiro, João T.; Lepenies, Bernd

    2017-01-01

    Recognition of viral glycans by pattern recognition receptors (PRRs) in innate immunity contributes to antiviral immune responses. C-type lectin receptors (CLRs) are PRRs capable of sensing glycans present in viral pathogens to activate antiviral immune responses such as phagocytosis, antigen processing and presentation, and subsequent T cell activation. The ability of CLRs to elicit and shape adaptive immunity plays a critical role in the inhibition of viral spread within the host. However, certain viruses exploit CLRs for viral entry into host cells to avoid immune recognition. To block CLR interactions with viral glycoproteins, antiviral strategies may involve the use of multivalent glycan carrier systems. In this review, we describe the role of CLRs in antiviral immunity and we highlight their dual function in viral clearance and exploitation by viral pathogens. PMID:28327518

  20. Guanylate-Binding Protein 1, an Interferon-Induced GTPase, Exerts an Antiviral Activity against Classical Swine Fever Virus Depending on Its GTPase Activity

    PubMed Central

    Li, Lian-Feng; Yu, Jiahui; Li, Yongfeng; Wang, Jinghan; Li, Su; Zhang, Lingkai; Xia, Shui-Li; Yang, Qian; Wang, Xiao; Yu, Shaoxiong; Luo, Yuzi; Sun, Yuan; Zhu, Yan; Munir, Muhammad

    2016-01-01

    ABSTRACT Many viruses trigger the type I interferon (IFN) pathway upon infection, resulting in the transcription of hundreds of interferon-stimulated genes (ISGs), which define the antiviral state of the host. Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), a highly contagious viral disease endangering the pig industry in many countries. However, anti-CSFV ISGs are poorly documented. Here we screened 20 ISGs that are commonly induced by type I IFNs against CSFV in lentivirus-delivered cell lines, resulting in the identification of guanylate-binding protein 1 (GBP1) as a potent anti-CSFV ISG. We observed that overexpression of GBP1, an IFN-induced GTPase, remarkably suppressed CSFV replication, whereas knockdown of endogenous GBP1 expression by small interfering RNAs significantly promoted CSFV growth. Furthermore, we demonstrated that GBP1 acted mainly on the early phase of CSFV replication and inhibited the translation efficiency of the internal ribosome entry site of CSFV. In addition, we found that GBP1 was upregulated at the transcriptional level in CSFV-infected PK-15 cells and in various organs of CSFV-infected pigs. Coimmunoprecipitation and glutathione S-transferase (GST) pulldown assays revealed that GBP1 interacted with the NS5A protein of CSFV, and this interaction was mapped in the N-terminal globular GTPase domain of GBP1. Interestingly, the K51 of GBP1, which is crucial for its GTPase activity, was essential for the inhibition of CSFV replication. We showed further that the NS5A-GBP1 interaction inhibited GTPase activity, which was critical for its antiviral effect. Taking our findings together, GBP1 is an anti-CSFV ISG whose action depends on its GTPase activity. IMPORTANCE Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), an economically important viral disease affecting the pig industry in many countries. To date, only a few host restriction factors against CSFV

  1. The Transcription Factor FoxK Participates with Nup98 To Regulate Antiviral Gene Expression

    PubMed Central

    Panda, Debasis; Gold, Beth; Tartell, Michael A.; Rausch, Keiko; Casas-Tinto, Sergio

    2015-01-01

    ABSTRACT Upon infection, pathogen recognition leads to a rapidly activated gene expression program that induces antimicrobial effectors to clear the invader. We recently found that Nup98 regulates the expression of a subset of rapidly activated antiviral genes to restrict disparate RNA virus infections in Drosophila by promoting RNA polymerase occupancy at the promoters of these antiviral genes. How Nup98 specifically targets these loci was unclear; however, it is known that Nup98 participates with transcription factors to regulate developmental-gene activation. We reasoned that additional transcription factors may facilitate the Nup98-dependent expression of antiviral genes. In a genome-wide RNA interference (RNAi) screen, we identified a relatively understudied forkhead transcription factor, FoxK, as active against Sindbis virus (SINV) in Drosophila. Here we find that FoxK is active against the panel of viruses that are restricted by Nup98, including SINV and vesicular stomatitis virus (VSV). Mechanistically, we show that FoxK coordinately regulates the Nup98-dependent expression of antiviral genes. Depletion of FoxK significantly reduces Nup98-dependent induction of antiviral genes and reduces the expression of a forkhead response element-containing luciferase reporter. Together, these data show that FoxK-mediated activation of gene expression is Nup98 dependent. We extended our studies to mammalian cells and found that the mammalian ortholog FOXK1 is antiviral against two disparate RNA viruses, SINV and VSV, in human cells. Interestingly, FOXK1 also plays a role in the expression of antiviral genes in mammals: depletion of FOXK1 attenuates virus-inducible interferon-stimulated response element (ISRE) reporter expression. Overall, our results demonstrate a novel role for FOXK1 in regulating the expression of antiviral genes, from insects to humans. PMID:25852164

  2. Human influenza is more effective than avian influenza at antiviral suppression in airway cells.

    PubMed

    Hsu, Alan Chen-Yu; Barr, Ian; Hansbro, Philip M; Wark, Peter A

    2011-06-01

    Airway epithelial cells are the initial site of infection with influenza viruses. The innate immune responses of airway epithelial cells to infection are important in limiting virus replication and spread. However, relatively little is known about the importance of this innate antiviral response to infection. Avian influenza viruses are a potential source of future pandemics; therefore, it is critical to examine the effectiveness of the host antiviral system to different influenza viruses. We used a human influenza (H3N2) and a low-pathogenic avian influenza (H11N9) to assess and compare the antiviral responses of Calu-3 cells. After infection, H3N2 replicated more effectively than the H11N9 in Calu-3 cells. This was not due to differential expression of sialic acid residues on Calu-3 cells, but was attributed to the interference of host antiviral responses by H3N2. H3N2 induced a delayed antiviral signaling and impaired type I and type III IFN induction compared with the H11N9. The gene encoding for nonstructural (NS) 1 protein was transfected into the bronchial epithelial cells (BECs), and the H3N2 NS1 induced a greater inhibition of antiviral responses compared with the H11N9 NS1. Although the low-pathogenic avian influenza virus was capable of infecting BECs, the human influenza virus replicated more effectively than avian influenza virus in BECs, and this was due to a differential ability of the two NS1 proteins to inhibit antiviral responses. This suggests that the subversion of human antiviral responses may be an important requirement for influenza viruses to adapt to the human host and cause disease.

  3. Antiviral activity of polyporoid mushrooms (higher Basidiomycetes) from Altai Mountains (Russia).

    PubMed

    Teplyakova, Tamara V; Psurtseva, Nadezhda V; Kosogova, Tatiana A; Mazurkova, Natalia A; Khanin, Viacheslav A; Vlasenko, Viacheslav A

    2012-01-01

    Antiviral activity against type A influenza virus of birds A/chicken/Kurgan/05/2005 (H5N1) and humans A/Aichi/2/68 (H3N2) was investigated for aqueous extracts from mycelium of 11 basidial fungi species collected in the Altai Mountains (Altai Republic, Russia). The most perspective strains for producing antiviral medicines are studied strains Daedaleopsis confragosa, Datronia mollis, Ischnoderma benzoinum, Trametes gibbosa, T. versicolor, Laricifomes officinalis, and Lenzites betulina.

  4. Increased Antiviral Treatment Among Hospitalized Children and Adults With Laboratory-Confirmed Influenza, 2010-2015.

    PubMed

    Appiah, Grace D; Chaves, Sandra S; Kirley, Pam D; Miller, Lisa; Meek, James; Anderson, Evan; Oni, Oluwakemi; Ryan, Patricia; Eckel, Seth; Lynfield, Ruth; Bargsten, Marisa; Zansky, Shelley M; Bennett, Nancy; Lung, Krista; McDonald-Hamm, Christie; Thomas, Ann; Brady, Diane; Lindegren, Mary L; Schaffner, William; Hill, Mary; Garg, Shikha; Fry, Alicia M; Campbell, Angela P

    2017-02-01

    (See the Editorial Commentary by Martin on pages 368-9.)Using population-based surveillance data, we analyzed antiviral treatment among hospitalized patients with laboratory-confirmed influenza. Treatment increased after the influenza A(H1N1) 2009 pandemic from 72% in 2010-2011 to 89% in 2014-2015 (P < .001). Overall, treatment was higher in adults (86%) than in children (72%); only 56% of cases received antivirals on the day of admission.

  5. Stockpiling anti-viral drugs for a pandemic: the role of Manufacturer Reserve Programs.

    PubMed

    Harrington, Joseph E; Hsu, Edbert B

    2010-05-01

    To promote stockpiling of anti-viral drugs by non-government organizations such as hospitals, drug manufacturers have introduced Manufacturer Reserve Programs which, for an annual fee, provide the right to buy in the event of a severe outbreak of influenza. We show that these programs enhance drug manufacturer profits but could either increase or decrease the amount of pre-pandemic stockpiling of anti-viral drugs.

  6. Antiviral mechanism of polyanionic carbosilane dendrimers against HIV-1

    PubMed Central

    Vacas-Córdoba, Enrique; Maly, Marek; De la Mata, Francisco J; Gómez, Rafael; Pion, Marjorie; Muñoz-Fernández, Mª Ángeles

    2016-01-01

    Nanotechnology-derived platforms, such as dendrimers, are very attractive in several biological applications. In the case of human immunodeficiency virus (HIV) infection, polyanionic carbosilane dendrimers have shown great potential as antiviral agents in the development of novel microbicides to prevent the sexual transmission of HIV-1. In this work, we studied the mechanism of two sulfated and naphthylsulfonated functionalized carbosilane dendrimers, G3-S16 and G2-NF16. They are able to inhibit viral infection at fusion and thus at the entry step. Both compounds impede the binding of viral particles to target cell surface and membrane fusion through the blockage of gp120–CD4 interaction. In addition, and for the first time, we demonstrate that dendrimers can inhibit cell-to-cell HIV transmission and difficult infectious synapse formation. Thus, carbosilane dendrimers’ mode of action is a multifactorial process targeting several proteins from viral envelope and from host cells that could block HIV infection at different stages during the first step of infection. PMID:27103798

  7. Chemokine receptors as new molecular targets for antiviral therapy.

    PubMed

    Santoro, F; Vassena, L; Lusso, P

    2004-04-01

    Extraordinary advancements have been made over the past decade in our understanding of the molecular mechanism of human immunodeficiency virus (HIV) entry into cells. The external HIV envelope glycoprotein, gp120, sequentially interacts with two cellular receptor molecules, the CD4 glycoprotein and a chemokine receptor, such as CCR5 or CXCR4, leading to the activation of the fusogenic domain of the transmembrane viral glycoprotein, gp41, which changes its conformation to create a hairpin structure that eventually triggers fusion between the viral and cellular membranes. Each of these discrete steps in the viral entry process represents a potential target for new antiviral agents. Current efforts to develop safe and effective HlV entry inhibitors are focused on naturally occurring proteins (e.g., chemokines, antibodies), engineered or modified derivatives of natural proteins (e.g., multimerized soluble CD4, gp41--or chemokine--derived synthetic peptides), as well as small synthetic compounds obtained either by high-throughput screening of large compound libraries or by structure-guided rational design. The recent introduction in therapy of the first fusion inhibitor, the gp41-derived synthetic peptide T20, heralds a new era in the treatment of AIDS, which will hopefully lead to more effective multi-drug regimens with reduced adverse effects for the patients.

  8. The antiviral activity of tetrazole phosphonic acids and their analogues.

    PubMed Central

    Hutchinson, D W; Naylor, M

    1985-01-01

    5-(Phosphonomethyl)-1H-tetrazole and a number of related tetrazoles have been prepared and their effects on the replication of Herpes Simplex Viruses-1 and -2 have been investigated as well as their abilities to inhibit the DNA polymerases induced by these viruses and the RNA transcriptase activity of influenza virus A. Contrary to an earlier report, 5-(phosphonomethyl)-1H-tetrazole was not an efficient inhibitor of the replication of HSV-1 and HSV-2 in tissue culture. Analogues of 5-(phosphonomethyl)-1H-tetrazole were also devoid of significant antiviral activity. Only 5-(phosphonomethyl)-1H-tetrazole and 5-(thiophosphonomethyl)-1H-tetrazole inhibited the influenza virus transcriptase, and both were more effective as inhibitors than phosphonoacetic acid under the same conditions. The DNA polymerases induced by HSV-1 and HSV-2 were inhibited slightly by 5-(phosphonomethyl)-1H-tetrazole and to a lesser extent by its N-ethyl analogue and 3-(phosphonomethyl)-1H-1,2,4-triazole. None of these compounds were as effective as phosphonoacetic acid. 5-(Thiophosphonomethyl)-1H-tetrazole was a better inhibitor of the DNA polymerase induced by HSV-1 than 5-(phosphonomethyl)-1H-tetrazole. PMID:2417198

  9. Autophagy functions as an antiviral mechanism against geminiviruses in plants

    PubMed Central

    Haxim, Yakupjan; Ismayil, Asigul; Jia, Qi; Wang, Yan; Zheng, Xiyin; Chen, Tianyuan; Qian, Lichao; Liu, Na; Wang, Yunjing; Han, Shaojie; Cheng, Jiaxuan; Qi, Yijun; Hong, Yiguo; Liu, Yule

    2017-01-01

    Autophagy is an evolutionarily conserved process that recycles damaged or unwanted cellular components, and has been linked to plant immunity. However, how autophagy contributes to plant immunity is unknown. Here we reported that the plant autophagic machinery targets the virulence factor βC1 of Cotton leaf curl Multan virus (CLCuMuV) for degradation through its interaction with the key autophagy protein ATG8. A V32A mutation in βC1 abolished its interaction with NbATG8f, and virus carrying βC1V32A showed increased symptoms and viral DNA accumulation in plants. Furthermore, silencing of autophagy-related genes ATG5 and ATG7 reduced plant resistance to the DNA viruses CLCuMuV, Tomato yellow leaf curl virus, and Tomato yellow leaf curl China virus, whereas activating autophagy by silencing GAPC genes enhanced plant resistance to viral infection. Thus, autophagy represents a novel anti-pathogenic mechanism that plays an important role in antiviral immunity in plants. DOI: http://dx.doi.org/10.7554/eLife.23897.001 PMID:28244873

  10. HCV-targeted antivirals: current status and future challenges.

    PubMed

    Gemma, Sandra; Brogi, Simone; Novellino, Ettore; Campiani, Giuseppe; Maga, Giovanni; Brindisi, Margherita; Butini, Stefania

    2014-01-01

    Hepatitis C virus (HCV) is the major etiological agent of human non-A and non-B hepatitis, affecting more than 170 million people worldwide. While the current standard of care for the treatment of HCV infection is ribavirin in combination with interferon-α (IFN-α), this therapeutic regimen presents several drawbacks, mainly related to important and serious side effects, to resistance issues, and to the lack of efficacy for the treatment of specific viral genotypes. In 2011, the FDA approved two HCV-targeted antivirals, namely boceprevir and telaprevir. These two drugs inhibit the protease activity of the viral enzyme NS3/4A, and in Phase III clinical trials proved to be effective in achieving sustained virological response rate up to 75%. However, problems associated with these therapeutic regimens still exist and need to be addressed. Intense research efforts in the field are aimed at discovering small-molecule inhibitors of HCV enzymes and proteins such as NS5B and NS5A and at developing NS3 protease inhibitors active against resistant viruses expressing mutated NS3 protease. The most recent advances for the rational drug design of such inhibitors are here reviewed.

  11. A small RNA targets pokeweed antiviral protein transcript.

    PubMed

    Klenov, Alexander; Neller, Kira C M; Burns, Lydia A; Krivdova, Gabriela; Hudak, Katalin A

    2016-03-01

    Ribosome-inactivating proteins (RIPs) are a class of plant defense proteins with N-glycosidase activity (EC 3.2.2.22). Pokeweed antiviral protein (PAP) is a Type I RIP isolated from the pokeweed plant, Phytolacca americana, thought to confer broad-spectrum virus resistance in this plant. Through a combination of standard molecular techniques and RNA sequencing analysis, we report here that a small RNA binds and cleaves the open reading frame of PAP mRNA. Additionally, sRNA targeting of PAP is dependent on jasmonic acid (JA), a plant hormone important for defense against pathogen infection and herbivory. Levels of small RNA increased with JA treatment, as did levels of PAP mRNA and protein, suggesting that the small RNA functions to moderate the expression of PAP in response to this hormone. The association between JA and PAP expression, mediated by sRNA299, situates PAP within a signaling pathway initiated by biotic stress. The consensus sequence of sRNA299 was obtained through bioinformatic analysis of pokeweed small RNA sequencing. To our knowledge, this is the first account of a sRNA targeting a RIP gene.

  12. Chemical diversity and antiviral potential in the pantropical Diospyros genus.

    PubMed

    Peyrat, Laure-Anne; Eparvier, Véronique; Eydoux, Cécilia; Guillemot, Jean-Claude; Stien, Didier; Litaudon, Marc

    2016-07-01

    A screening using a dengue replicon virus-cell-based assay was performed on 3563 ethyl acetate (EtOAc) extracts from different parts of 1500 plants. The screening led to the selection of species from the genus Diospyros (Ebenaceae), among which 25 species distributed in tropical areas showed significant inhibitory activity on dengue virus replication. A metabolic analysis was conducted from the UPLC-HRMS profiles of 33 biologically active and inactive plant extracts, and their metabolic proximity is presented in the form of a dendrogram. The results of the study showed that chemical similarity is not related to plant species or organ. Overall, metabolomic profiling allowed us to define large groups of extracts, comprising both active and inactive ones. Closely related profiles from active extracts might indicate that the common major components of these extracts were responsible for the antiviral activity, while the comparison of chemically similar active and inactive extracts, will permit to find compounds of interest. Eventually, the phytochemical investigation of Diospyros glans bark EtOAc extract afforded usnic acid and 7 known ursane- and lupane-type triterpenoids, among which 5 were found significantly active against dengue virus replication. The inhibitory potency of these compounds was also evaluated on a DENV-NS5 RNA-dependant RNA polymerase assay.

  13. Resistance to antivirals in human cytomegalovirus: mechanisms and clinical significance.

    PubMed

    Pérez, J L

    1997-09-01

    Long term therapies needed for managing human cytomegalovirus (HCMV) infections in immunosupressed patients provided the background for the emergence of the resistance to antivirals active against HCMV. In addition, laboratory selected mutants have also been readily achieved. Both clinical and laboratory resistant strains share the same determinants of resistance. Ganciclovir resistance may be due to a few mutations in the HCMV UL97 gene and/or viral DNA pol gene, the former being responsible for about 70% of clinical resistant isolates. Among them, V464, V594, S595 and F595 are the most frequent mutations. Because of their less extensive clinical use, much less is known about resistance to foscarnet and cidofovir (formerly, HPMPC) but in both cases, it has been associated to mutations in the DNA pol. Ganciclovir resistant strains showing DNA pol mutations are cross-resistant to cidofovir and their corresponding IC50 are normally higher than those from strains harboring only mutations at the UL97 gene. To date, foscarnet resistance seems to be independent of both ganciclovir and cidofovir resistance.

  14. Antiviral activity of Undaria pinnatifida against herpes simplex virus.

    PubMed

    Thompson, Kenneth D; Dragar, Charles

    2004-07-01

    The major component of an aqueous extract of the seaweed Undaria pinnati fi da has been identified previously as a galactofucan (GFS), a sulfated polysaccharide. The galactofucan was partially purified and the material tested in this study is 75% pure galactofucan sulfate. GFS was evaluated for antiviral activity against 32 clinical strains of herpes simplex virus (HSV): 14 strains of HSV-1 and 18 strains of HSV-2. Twelve strains (four HSV-1 and eight HSV-2) were resistant to acyclovir (ACV-R) and 20 strains (10 HSV-1 and 10 HSV-2) were susceptible to ACV (ACV-S). The median IC(50) of GFS for the 14 strains of HSV-1 was 32 micro g/mL. The median IC(50) of GFS for the 18 strains of HSV-2 was 0.5 micro g/mL. GFS is significantly more active against clinical strains of HSV-2 than HSV-1, p < 0.001. The mode of action of the GFS was shown to be the inhibition of viral binding and entry into the host cell. The cytotoxicity of GFS was >4.0 mg/mL in the neutral red dye uptake assay indicating that GFS is non-toxic in this assay.

  15. Use of antiviral therapy in patients with chronic hepatitis C

    PubMed Central

    Dragomiretskaya, Natalia; Izha, Anna; Kalinichenko, Nikolay; Szark-Eckardt, Mirosława; Klimczyk, Mariusz; Cieślicka, Mirosława; Muszkieta, Radosław; Prusik, Krzysztof; Napierała, Marek; Żukowska, Hanna

    2015-01-01

    Introduction The presence of background HCV infection cannot be overestimated in view of the prevalence of chronic hepatitis C and the risk of adverse outcomes of this disease. Purpose of this study was to evaluate the effectiveness of the combined use of antiviral therapy (Roferon + Vero-Ribavirin) and resort factors in patients with chronic hepatitis C in the phase of replication. Material and methods We observed 48 patients with chronic hepatitis C; the minimum level of activity of the process defined the phase of replication. Markers of HCV infection were determined by enzyme linked immunosorbent assay (ELISA) (a-HCV and HCV-Ig M). HCV RNA was determined twice by the polymerase chain reaction (PCR). Genotyping of hepatitis C virus was performed. Biochemical blood analysis and the study of HCV infection markers were carried out four times. Results of therapy were assessed immediately after the end of the resort (spa) treatment, then at 3, 6 and 12 months after starting treatment. At 12 months after starting treatment, all the observed patients had persistent clinical and biochemical remission. Elimination of the virus from the blood was noted in 56% of the control group and 74% of patients in the study group. Conclusions For patients with moderately active HCV, the replication phase was characterized by asthenic-vegetative syndrome (100% of patients) with severe depression (22.92%), pain (77.08%) and dyspeptic syndrome (33.33%), moderate hypertransferaseemia (100%), slightly pronounced cholestasis (33% of patients), and signs of mesenchymal-inflammatory response.

  16. Modulation of Antiviral Immunity by Heme Oxygenase-1.

    PubMed

    Espinoza, Janyra A; González, Pablo A; Kalergis, Alexis M

    2017-03-01

    Heme oxygenase-1 (HO-1) is a stress-inducible, anti-inflammatory, and cytoprotective enzyme expressed in most cell types in the organism. Under several stress stimuli, HO-1 expression and activity is up-regulated to catalyze the rate-limiting enzymatic step of heme degradation into carbon monoxide, free iron, and biliverdin. Besides its effects on cell metabolism, HO-1 is also capable of modulating host innate and adaptive immune responses in response to sepsis, transplantation, and autoimmunity, and preventing oxidative damage associated with inflammation. In addition, recent studies have reported that HO-1 can exert a significant antiviral activity against a wide variety of viruses, including HIV, hepatitis C virus, hepatitis B virus, enterovirus 71, influenza virus, respiratory syncytial virus, dengue virus, and Ebola virus, among others. Herein, we address the current understanding of the functional significance of HO-1 against a variety of viruses and its potential as a therapeutic strategy to prevent and control viral infections. Furthermore, we review the most important features of the immunoregulatory functions for this enzyme.

  17. Matrix Metalloproteinase 9 Exerts Antiviral Activity against Respiratory Syncytial Virus

    PubMed Central

    Dabo, Abdoulaye J.; Cummins, Neville; Eden, Edward; Geraghty, Patrick

    2015-01-01

    Increased lung levels of matrix metalloproteinase 9 (MMP9) are frequently observed during respiratory syncytial virus (RSV) infection and elevated MMP9 concentrations are associated with severe disease. However little is known of the functional role of MMP9 during lung infection with RSV. To determine whether MMP9 exerted direct antiviral potential, active MMP9 was incubated with RSV, which showed that MMP9 directly prevented RSV infectivity to airway epithelial cells. Using knockout mice the effect of the loss of Mmp9 expression was examined during RSV infection to demonstrate MMP9’s role in viral clearance and disease progression. Seven days following RSV infection, Mmp9-/- mice displayed substantial weight loss, increased RSV-induced airway hyperresponsiveness (AHR) and reduced clearance of RSV from the lungs compared to wild type mice. Although total bronchoalveolar lavage fluid (BALF) cell counts were similar in both groups, neutrophil recruitment to the lungs during RSV infection was significantly reduced in Mmp9-/- mice. Reduced neutrophil recruitment coincided with diminished RANTES, IL-1β, SCF, G-CSF expression and p38 phosphorylation. Induction of p38 signaling was required for RANTES and G-CSF expression during RSV infection in airway epithelial cells. Therefore, MMP9 in RSV lung infection significantly enhances neutrophil recruitment, cytokine production and viral clearance while reducing AHR. PMID:26284919

  18. The Antimicrobial and Antiviral Applications of Cell-Penetrating Peptides.

    PubMed

    Pärn, Kalle; Eriste, Elo; Langel, Ülo

    2015-01-01

    Over the past two decades, cell-penetrating peptides (CPPs) have become increasingly popular both in research and in application. There have been numerous studies on the physiochemical characteristics and behavior of CPPs in various environments; likewise, the mechanisms of entry and delivery capabilities of these peptides have also been extensively researched. Besides the fundamental issues, there is an enormous interest in the delivery capabilities of the peptides as the family of CPPs is a promising and mostly non-toxic delivery vector candidate for numerous medical applications such as gene silencing, transgene delivery, and splice correction. Lately, however, there has been an emerging field of study besides the high-profile gene therapy applications-the use of peptides and CPPs to combat various infections caused by harmful bacteria, fungi, and viruses.In this chapter, we aim to provide a short overview of the history and properties of CPPs which is followed by more thorough descriptions of antimicrobial and antiviral peptides. To achieve this, we analyze the origin of such peptides, give an overview of the mechanisms of action and discuss the various practical applications which are ongoing or have been suggested based on research.

  19. New Class of Orthopoxvirus Antiviral Drugs That Block Viral Maturation

    PubMed Central

    Byrd, Chelsea M.; Bolken, Tove' C.; Mjalli, Adnan M.; Arimilli, Murty N.; Andrews, Robert C.; Rothlein, Robert; Andrea, Tariq; Rao, Mohan; Owens, Katrina L.; Hruby, Dennis E.

    2004-01-01

    By using a homology-based bioinformatics approach, a structural model of the vaccinia virus (VV) I7L proteinase was developed. A unique chemical library of ∼51,000 compounds was computationally queried to identify potential active site inhibitors. The resulting biased subset of compounds was assayed for both toxicity and the ability to inhibit the growth of VV in tissue culture cells. A family of chemotypically related compounds was found which exhibits selective activity against orthopoxviruses, inhibiting VV with 50% inhibitory concentrations of 3 to 12 μM. These compounds exhibited no significant cytotoxicity in the four cell lines tested and did not inhibit the growth of other organisms such as Saccharomyces cerevisiae, Pseudomonas aeruginosa, adenovirus, or encephalomyocarditis virus. Phenotypic analyses of virus-infected cells were conducted in the presence of active compounds to verify that the correct biochemical step (I7L-mediated core protein processing) was being inhibited. Electron microscopy of compound-treated VV-infected cells indicated a block in morphogenesis. Compound-resistant viruses were generated and resistance was mapped to the I7L open reading frame. Transient expression with the mutant I7L gene rescued the ability of wild-type virus to replicate in the presence of compound, indicating that this is the only gene necessary for resistance. This novel class of inhibitors has potential for development as an efficient antiviral drug against pathogenic orthopoxviruses, including smallpox. PMID:15507601

  20. piRNA pathway is not required for antiviral defense in Drosophila melanogaster.

    PubMed

    Petit, Marine; Mongelli, Vanesa; Frangeul, Lionel; Blanc, Hervé; Jiggins, Francis; Saleh, Maria-Carla

    2016-07-19

    Since its discovery, RNA interference has been identified as involved in many different cellular processes, and as a natural antiviral response in plants, nematodes, and insects. In insects, the small interfering RNA (siRNA) pathway is the major antiviral response. In recent years, the Piwi-interacting RNA (piRNA) pathway also has been implicated in antiviral defense in mosquitoes infected with arboviruses. Using Drosophila melanogaster and an array of viruses that infect the fruit fly acutely or persistently or are vertically transmitted through the germ line, we investigated in detail the extent to which the piRNA pathway contributes to antiviral defense in adult flies. Following virus infection, the survival and viral titers of Piwi, Aubergine, Argonaute-3, and Zucchini mutant flies were similar to those of wild type flies. Using next-generation sequencing of small RNAs from wild type and siRNA mutant flies, we showed that no viral-derived piRNAs were produced in fruit flies during different types of viral infection. Our study provides the first evidence, to our knowledge, that the piRNA pathway does not play a major role in antiviral defense in adult Drosophila and demonstrates that viral-derived piRNA production depends on the biology of the host-virus combination rather than being part of a general antiviral process in insects.

  1. Antiviral Activity of Graphene–Silver Nanocomposites against Non-Enveloped and Enveloped Viruses

    PubMed Central

    Chen, Yi-Ning; Hsueh, Yi-Huang; Hsieh, Chien-Te; Tzou, Dong-Ying; Chang, Pai-Ling

    2016-01-01

    The discovery of novel antiviral materials is important because many infectious diseases are caused by viruses. Silver nanoparticles have demonstrated strong antiviral activity, and graphene is a potential antimicrobial material due to its large surface area, high carrier mobility, and biocompatibility. No studies on the antiviral activity of nanomaterials on non-enveloped viruses have been reported. To investigate the antiviral activity of graphene oxide (GO) sheets and GO sheets with silver particles (GO-Ag) against enveloped and non-enveloped viruses, feline coronavirus (FCoV) with an envelope and infectious bursal disease virus (IBDV) without an envelope were chosen. The morphology and sizes of GO and GO-Ag were characterized by transmission, scanning electron microscopy, and X-ray diffraction. A virus inhibition assay was used to identify the antiviral activity of GO and GO-Ag. Go-Ag inhibited 25% of infection by FCoV and 23% by IBDV, whereas GO only inhibited 16% of infection by FCoV but showed no antiviral activity against the infection by IBDV. Further application of GO and GO-Ag can be considered for personal protection equipment to decrease the transmission of viruses. PMID:27104546

  2. Using the Ferret as an Animal Model for Investigating Influenza Antiviral Effectiveness

    PubMed Central

    Oh, Ding Y.; Hurt, Aeron C.

    2016-01-01

    The concern of the emergence of a pandemic influenza virus has sparked an increased effort toward the development and testing of novel influenza antivirals. Central to this is the animal model of influenza infection, which has played an important role in understanding treatment effectiveness and the effect of antivirals on host immune responses. Among the different animal models of influenza, ferrets can be considered the most suitable for antiviral studies as they display most of the human-like symptoms following influenza infections, they can be infected with human influenza virus without prior viral adaptation and have the ability to transmit influenza virus efficiently between one another. However, an accurate assessment of the effectiveness of an antiviral treatment in ferrets is dependent on three major experimental considerations encompassing firstly, the volume and titer of virus, and the route of viral inoculation. Secondly, the route and dose of drug administration, and lastly, the different methods used to assess clinical symptoms, viral shedding kinetics and host immune responses in the ferrets. A good understanding of these areas is necessary to achieve data that can accurately inform the human use of influenza antivirals. In this review, we discuss the current progress and the challenges faced in these three major areas when using the ferret model to measure influenza antiviral effectiveness. PMID:26870031

  3. In vitro evaluation of marine-microorganism extracts for anti-viral activity.

    PubMed

    Yasuhara-Bell, Jarred; Yang, Yongbo; Barlow, Russell; Trapido-Rosenthal, Hank; Lu, Yuanan

    2010-08-07

    Viral-induced infectious diseases represent a major health threat and their control remains an unachieved goal, due in part to the limited availability of effective anti-viral drugs and measures. The use of natural products in drug manufacturing is an ancient and well-established practice. Marine organisms are known producers of pharmacological and anti-viral agents. In this study, a total of 20 extracts from marine microorganisms were evaluated for their antiviral activity. These extracts were tested against two mammalian viruses, herpes simplex virus (HSV-1) and vesicular stomatitis virus (VSV), using Vero cells as the cell culture system, and two marine virus counterparts, channel catfish virus (CCV) and snakehead rhabdovirus (SHRV), in their respective cell cultures (CCO and EPC). Evaluation of these extracts demonstrated that some possess antiviral potential. In sum, extracts 162M(4), 258M(1), 298M(4), 313(2), 331M(2), 367M(1) and 397(1) appear to be effective broad-spectrum antivirals with potential uses as prophylactic agents to prevent infection, as evident by their highly inhibitive effects against both virus types. Extract 313(2) shows the most potential in that it showed significantly high inhibition across all tested viruses. The samples tested in this study were crude extracts; therefore the development of antiviral application of the few potential extracts is dependent on future studies focused on the isolation of the active elements contained in these extracts.

  4. Antiviral antibodies target adenovirus to phagolysosomes and amplify the innate immune response.

    PubMed

    Zaiss, Anne K; Vilaysane, Akosua; Cotter, Matthew J; Clark, Sharon A; Meijndert, H Christopher; Colarusso, Pina; Yates, Robin M; Petrilli, Virginie; Tschopp, Jurg; Muruve, Daniel A

    2009-06-01

    Adenovirus is a nonenveloped dsDNA virus that activates intracellular innate immune pathways. In vivo, adenovirus-immunized mice displayed an enhanced innate immune response and diminished virus-mediated gene delivery following challenge with the adenovirus vector AdLacZ suggesting that antiviral Abs modulate viral interactions with innate immune cells. Under naive serum conditions in vitro, adenovirus binding and internalization in macrophages and the subsequent activation of innate immune mechanisms were inefficient. In contrast to the neutralizing effect observed in nonhematopoietic cells, adenovirus infection in the presence of antiviral Abs significantly increased FcR-dependent viral internalization in macrophages. In direct correlation with the increased viral internalization, antiviral Abs amplified the innate immune response to adenovirus as determined by the expression of NF-kappaB-dependent genes, type I IFNs, and caspase-dependent IL-1beta maturation. Immune serum amplified TLR9-independent type I IFN expression and enhanced NLRP3-dependent IL-1beta maturation in response to adenovirus, confirming that antiviral Abs specifically amplify intracellular innate pathways. In the presence of Abs, confocal microscopy demonstrated increased targeting of adenovirus to LAMP1-positive phagolysosomes in macrophages but not epithelial cells. These data show that antiviral Abs subvert natural viral tropism and target the adenovirus to phagolysosomes and the intracellular innate immune system in macrophages. Furthermore, these results illustrate a cross-talk where the adaptive immune system positively regulates the innate immune system and the antiviral state.

  5. 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

  6. The potential of antiviral agents to control classical swine fever: a modelling study.

    PubMed

    Backer, Jantien A; Vrancken, Robert; Neyts, Johan; Goris, Nesya

    2013-09-01

    Classical swine fever (CSF) represents a continuous threat to pig populations that are free of disease without vaccination. When CSF virus is introduced, the minimal control strategy imposed by the EU is often insufficient to mitigate the epidemic. Additional measures such as preemptive culling encounter ethical objections, whereas emergency vaccination leads to prolonged export restrictions. Antiviral agents, however, provide instantaneous protection without inducing an antibody response. The use of antiviral agents to contain CSF epidemics is studied with a model describing within- and between-herd virus transmission. Epidemics are simulated in a densely populated livestock area in The Netherlands, with farms of varying sizes and pig types (finishers, piglets and sows). Our results show that vaccination and/or antiviral treatment in a 2 km radius around an infected herd is more effective than preemptive culling in a 1 km radius. However, the instantaneous but temporary protection provided by antiviral treatment is slightly less effective than the delayed but long-lasting protection offered by vaccination. Therefore, the most effective control strategy is to vaccinate animals when allowed (finishers and piglets) and to treat with antiviral agents when vaccination is prohibited (sows). As independent control measure, antiviral treatment in a 1 km radius presents an elevated risk of epidemics running out of control. A 2 km control radius largely eliminates this risk.

  7. Current management and recommendations for access to antiviral therapy of herpes labialis.

    PubMed

    Cunningham, Anthony; Griffiths, Paul; Leone, Peter; Mindel, Adrian; Patel, Rajul; Stanberry, Lawrence; Whitley, Richard

    2012-01-01

    Herpes labialis is a common skin infective condition, worldwide, which is primarily caused by HSV-1. Recurrent episodes of herpes labialis, also known as cold sores, can be frequent, painful, long-lasting and disfiguring for infected patients. At present, there are two types of antivirals for the treatment of herpes labialis, topical and oral, which are available over the counter or as prescription-only. The aim of antiviral therapy is to block viral replication to enable shortening the duration of symptoms and to accelerate healing of the lesions associated with herpes labialis. This review examines the evidence for the effectiveness of current topical and oral antivirals in the management of recurrent episodes of herpes labialis. In most countries, oral antivirals for herpes labialis are available as prescription-only. However, in early 2010, the oral antiviral famciclovir was reclassified from prescription-only medicine to pharmacist-controlled status in New Zealand. The benefits and risks associated with moving an antiviral therapy for herpes labialis from prescription-only to pharmacist-controlled status are reviewed here, and the implications for patients, general physicians and pharmacists are considered.

  8. RNAi and antiviral defense in Drosophila: setting up a systemic immune response.

    PubMed

    Karlikow, Margot; Goic, Bertsy; Saleh, Maria-Carla

    2014-01-01

    RNA interference (RNAi) controls gene expression in eukaryotic cells and thus, cellular homeostasis. In addition, in plants, nematodes and arthropods it is a central antiviral effector mechanism. Antiviral RNAi has been well described as a cell autonomous response, which is triggered by double-stranded RNA (dsRNA) molecules. This dsRNA is the precursor for the silencing of viral RNA in a sequence-specific manner. In plants, systemic antiviral immunity has been demonstrated, however much less is known in animals. Recently, some evidence for a systemic antiviral response in arthropods has come to light. Cell autonomous RNAi may not be sufficient to reach an efficient antiviral response, and the organism might rely on the spread and uptake of an RNAi signal of unknown origin. In this review, we offer a perspective on how RNAi-mediated antiviral immunity could confer systemic protection in insects and we propose directions for future research to understand the mechanism of RNAi-immune signal sorting, spreading and amplification.

  9. piRNA pathway is not required for antiviral defense in Drosophila melanogaster

    PubMed Central

    Petit, Marine; Mongelli, Vanesa; Frangeul, Lionel; Blanc, Hervé; Jiggins, Francis; Saleh, Maria-Carla

    2016-01-01

    Since its discovery, RNA interference has been identified as involved in many different cellular processes, and as a natural antiviral response in plants, nematodes, and insects. In insects, the small interfering RNA (siRNA) pathway is the major antiviral response. In recent years, the Piwi-interacting RNA (piRNA) pathway also has been implicated in antiviral defense in mosquitoes infected with arboviruses. Using Drosophila melanogaster and an array of viruses that infect the fruit fly acutely or persistently or are vertically transmitted through the germ line, we investigated in detail the extent to which the piRNA pathway contributes to antiviral defense in adult flies. Following virus infection, the survival and viral titers of Piwi, Aubergine, Argonaute-3, and Zucchini mutant flies were similar to those of wild type flies. Using next-generation sequencing of small RNAs from wild type and siRNA mutant flies, we showed that no viral-derived piRNAs were produced in fruit flies during different types of viral infection. Our study provides the first evidence, to our knowledge, that the piRNA pathway does not play a major role in antiviral defense in adult Drosophila and demonstrates that viral-derived piRNA production depends on the biology of the host–virus combination rather than being part of a general antiviral process in insects. PMID:27357659

  10. Using the Ferret as an Animal Model for Investigating Influenza Antiviral Effectiveness.

    PubMed

    Oh, Ding Y; Hurt, Aeron C

    2016-01-01

    The concern of the emergence of a pandemic influenza virus has sparked an increased effort toward the development and testing of novel influenza antivirals. Central to this is the animal model of influenza infection, which has played an important role in understanding treatment effectiveness and the effect of antivirals on host immune responses. Among the different animal models of influenza, ferrets can be considered the most suitable for antiviral studies as they display most of the human-like symptoms following influenza infections, they can be infected with human influenza virus without prior viral adaptation and have the ability to transmit influenza virus efficiently between one another. However, an accurate assessment of the effectiveness of an antiviral treatment in ferrets is dependent on three major experimental considerations encompassing firstly, the volume and titer of virus, and the route of viral inoculation. Secondly, the route and dose of drug administration, and lastly, the different methods used to assess clinical symptoms, viral shedding kinetics and host immune responses in the ferrets. A good understanding of these areas is necessary to achieve data that can accurately inform the human use of influenza antivirals. In this review, we discuss the current progress and the challenges faced in these three major areas when using the ferret model to measure influenza antiviral effectiveness.

  11. The antiviral drug acyclovir is a slow-binding inhibitor of (D)-amino acid oxidase.

    PubMed

    Katane, Masumi; Matsuda, Satsuki; Saitoh, Yasuaki; Sekine, Masae; Furuchi, Takemitsu; Koyama, Nobuhiro; Nakagome, Izumi; Tomoda, Hiroshi; Hirono, Shuichi; Homma, Hiroshi

    2013-08-20

    d-Amino acid oxidase (DAO) is a degradative enzyme that is stereospecific for d-amino acids, including d-serine and d-alanine, which are believed to be coagonists of the N-methyl-d-aspartate (NMDA) receptor. To identify a new class of DAO inhibitor(s) that can be used to elucidate the molecular details of the active site environment of DAO, manifold biologically active compounds of microbial origin and pre-existing drugs were screened for their ability to inhibit DAO activity, and several compounds were identified as candidates. One of these compounds, acyclovir (ACV), a well-known antiviral drug used for the treatment of herpesvirus infections, was characterized and evaluated as a novel DAO inhibitor in vitro. Analysis showed that ACV acts on DAO as a reversible slow-binding inhibitor, and interestingly, the time required to achieve equilibrium between DAO, ACV, and the DAO/ACV complex was highly dependent on temperature. The binding mechanism of ACV to DAO was investigated in detail by several approaches, including kinetic analysis, structural modeling of DAO complexed with ACV, and site-specific mutagenesis of an active site residue postulated to be involved in the binding of ACV. The results confirm that ACV is a novel, active site-directed inhibitor of DAO that can be a valuable tool for investigating the structure-function relationships of DAO, including the molecular details of the active site environment of DAO. In particular, it appears that ACV can serve as an active site probe to study the structural basis of temperature-induced conformational changes of DAO.

  12. Evaluation of Ag nanoparticle coated air filter against aerosolized virus: Anti-viral efficiency with dust loading.

    PubMed

    Joe, Yun Haeng; Park, Dae Hoon; Hwang, Jungho

    2016-01-15

    In this study, the effect of dust loading on the anti-viral ability of an anti-viral air filter was investigated. Silver nanoparticles approximately 11 nm in diameter were synthesized via a spark discharge generation system and were used as anti-viral agents coated onto a medium air filter. The pressure drop, filtration efficiency, and anti-viral ability of the filter against aerosolized bacteriophage MS2 virus particles were tested with dust loading. The filtration efficiency and pressure drop increased with dust loading, while the anti-viral ability decreased. Theoretical analysis of anti-viral ability with dust loading was carried out using a mathematical model based on that presented by Joe et al. (J. Hazard. Mater.; 280: 356-363, 2014). Our model can be used to compare anti-viral abilities of various anti-viral agents, determine appropriate coating areal density of anti-viral agent on a filter, and predict the life cycle of an anti-viral filter.

  13. High Serum Lipopolysaccharide-Binding Protein Level in Chronic Hepatitis C Viral Infection Is Reduced by Anti-Viral Treatments

    PubMed Central

    Nien, Hsiao-Ching; Hsu, Shih-Jer; Su, Tung-Hung; Yang, Po-Jen; Sheu, Jin-Chuan; Wang, Jin-Town; Chow, Lu-Ping; Chen, Chi-Ling

    2017-01-01

    Background Lipopolysaccharide-binding protein (LBP) has been reported to associate with metabolic diseases, such as obesity, diabetes, and non-alcoholic fatty liver disease. Since chronic hepatitis C virus (HCV) infection is associated with metabolic derangements, the relationship between LBP and HCV deserves additional studies. This study aimed to determine the serum LBP level in subjects with or without HCV infection and investigate the change of its level after anti-viral treatments with or without interferon. Methods and Findings We recruited 120 non-HCV subjects, 42 and 17 HCV-infected subjects respectively treated with peginterferon α-2a/ribavirin and direct-acting antiviral drugs. Basic information, clinical data, serum LBP level and abdominal ultrasonography were collected. All the subjects provided written informed consent before being enrolled approved by the Research Ethics Committee of the National Taiwan University Hospital. Serum LBP level was significantly higher in HCV-infected subjects than non-HCV subjects (31.0 ± 8.8 versus 20.0 ± 6.4 μg/mL; p-value < 0.001). After multivariate analyses, LBP at baseline was independently associated with body mass index, hemoglobin A1c, alanine aminotransferase (ALT) and HCV infection. Moreover, the baseline LBP was only significantly positively associated with ALT and inversely with fatty liver in HCV-infected subjects. The LBP level significantly decreased at sustained virologic response (27.4 ± 6.6 versus 34.6 ± 7.3 μg/mL, p-value < 0.001; 15.9 ± 4.4 versus 22.2 ± 5.7 μg/mL, p-value = 0.001), regardless of interferon-based or -free therapy. Conclusions LBP, an endotoxemia associated protein might be used as an inflammatory biomarker of both infectious and non-infectious origins in HCV-infected subjects. PMID:28107471

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

    PubMed

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

    2015-10-15

    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.

  15. Antiviral Combination Approach as a Perspective to Combat Enterovirus Infections.

    PubMed

    Galabov, Angel S; Nikolova, Ivanka; Vassileva-Pencheva, Ralitsa; Stoyanova, Adelina

    2015-01-01

    Human enteroviruses distributed worldwide are causative agents of a broad spectrum of diseases with extremely high morbidity, including a series of severe illnesses of the central nervous system, heart, endocrine pancreas, skeleton muscles, etc., as well as the common cold contributing to the development of chronic respiratory diseases, including the chronic obstructive pulmonary disease. The above mentioned diseases along with the significantly high morbidity and mortality in children, as well as in the high-risk populations (immunodeficiencies, neonates) definitely formulate the chemotherapy as the main tool for the control of enterovirus infections. At present, clinically effective antivirals for use in the treatment of enteroviral infection do not exist, in spite of the large amount of work carried out in this field. The main reason for this is the development of drug resistance. We studied the process of development of resistance to the strongest inhibitors of enteroviruses, WIN compounds (VP1 protein hydrophobic pocket blockers), especially in the models in vivo, Coxsackievirus B (CV-B) infections in mice. We introduced the tracing of a panel of phenotypic markers (MIC50 value, plaque shape and size, stability at 50℃, pathogenicity in mice) for characterization of the drug-mutants (resistant and dependent) as a very important stage in the study of enterovirus inhibitors. Moreover, as a result of VP1 RNA sequence analysis performed on the model of disoxaril mutants of CVB1, we determined the molecular basis of the drug-resistance. The monotherapy courses were the only approach used till now. For the first time in the research for anti-enterovirus antivirals our team introduced the testing of combination effect of the selective inhibitors of enterovirus replication with different mode of action. This study resulted in the selection of a number of very effective in vitro double combinations with synergistic effect and a broad spectrum of sensitive

  16. Leaf proteome analysis of transgenic plants expressing antiviral antibodies.

    PubMed

    Di Carli, Mariasole; Villani, Maria Elena; Renzone, Giovanni; Nardi, Luca; Pasquo, Alessandra; Franconi, Rosella; Scaloni, Andrea; Benvenuto, Eugenio; Desiderio, Angiola

    2009-02-01

    The expression of exogenous antibodies in plant is an effective strategy to confer protection against viral infection or to produce molecules with pharmaceutical interest. However, the acceptance of the transgenic technology to obtain self-protecting plants depends on the assessment of their substantial equivalence compared to non-modified crops with an established history of safe use. In fact, the possibility exists that the introduction of transgenes in plants may alter expression of endogenous genes and/or normal production of metabolites. In this study, we investigated whether the expression in plant of recombinant antibodies directed against viral proteins may influence the host leaf proteome. Two transgenic plant models, generated by Agrobacterium tumefaciens-mediated transformation, were analyzed for this purpose, namely, Lycopersicon esculentum cv. MicroTom and Nicotiana benthamiana, expressing recombinant antibodies against cucumber mosaic virus and tomato spotted wilt virus, respectively. To obtain a significant representation of plant proteomes, optimized extraction procedures have been devised for each plant species. The proteome repertoire of antibody-expressing and control plants was compared by 2-DE associated to DIGE technology. Among the 2000 spots detected within the gels, about 10 resulted differentially expressed in each transgenic model and were identified by MALDI-TOF PMF and muLC-ESI-IT-MS/MS procedures. Protein variations were restricted to a limited number of defined differences with an average ratio below 2.4. Most of the differentially expressed proteins were related to photosynthesis or defense function. The overall results suggest that the expression of recombinant antibodies in both systems does not significantly alter the leaf proteomic profile, contributing to assess the biosafety of resistant plants expressing antiviral antibodies.

  17. Common antiviral cytotoxic t-lymphocyte epitope for diverse arenaviruses.

    PubMed

    Oldstone, M B; Lewicki, H; Homann, D; Nguyen, C; Julien, S; Gairin, J E

    2001-07-01

    Members of the Arenaviridae family have been isolated from mammalian hosts in disparate geographic locations, leading to their grouping as Old World types (i.e., lymphocytic choriomeningitis virus [LCMV], Lassa fever virus [LFV], Mopeia virus, and Mobala virus) and New World types (i.e., Junin, Machupo, Tacaribe, and Sabia viruses) (C. J. Peters, M. J. Buchmeier, P. E. Rollin, and T. G. Ksiazek, p. 1521-1551, in B. N. Fields, D. M. Knipe, and P. M. Howley [ed.], Fields virology, 3rd ed., 1996; P. J. Southern, p. 1505-1519, in B. N. Fields, D. M. Knipe, and P. M. Howley [ed.], Fields virology, 3rd ed., 1996). Several types in both groups-LFV, Junin, Machupo, and Sabia viruses-cause severe and often lethal human diseases. By sequence comparison, we noted that eight Old World and New World arenaviruses share several amino acids with the nucleoprotein (NP) that consists of amino acids (aa) 118 to 126 (NP 118-126) (RPQASGVYM) of LCMV that comprise the immunodominant cytotoxic T-lymphocyte (CTL) epitope for H-2(d) mice (32). This L(d)-restricted epitope constituted >97% of the total bulk CTLs produced in the specific antiviral or clonal responses of H-2(d) BALB mice. NP 118-126 of the Old World arenaviruses LFV, Mopeia virus, and LCMV and the New World arenavirus Sabia virus bound at high affinity to L(d). The primary H-2(d) CTL anti-LCMV response as well as that of a CTL clone responsive to LCMV NP 118-126 recognized target cells coated with NP 118-126 peptides derived from LCMV, LFV, and Mopeia virus but not Sabia virus, indicating that a common functional NP epitope exists among Old World arenaviruses. Use of site-specific amino acid exchanges in the NP CTL epitope among these arenaviruses identified amino acids involved in major histocompatibility complex binding and CTL recognition.

  18. Antiviral and cellular metabolism interactions between Dexelvucitabine and lamivudine.

    PubMed

    Hernandez-Santiago, Brenda I; Mathew, Judy S; Rapp, Kim L; Grier, Jason P; Schinazi, Raymond F

    2007-06-01

    Studies on cellular drug interactions with antiretroviral agents prior to clinical trials are critical to detect possible drug interactions. Herein, we demonstrated that two 2'-deoxycytidine antiretroviral agents, dexelvucitabine (known as beta-d-2',3'-didehydro-2',3'-dideoxy-5-fluorocytidine, DFC, d-d4FC, or RVT) and lamivudine (3TC), combined in primary human peripheral blood mononuclear (PBM) cells infected with human immunodeficiency virus 1 strain LAI (HIV-1(LAI)), resulted in additive-to-synergistic effects. The cellular metabolism of DFC and 3TC was studied in human T-cell lymphoma (CEM) and in primary human PBM cells to determine whether this combination caused any reduction in active nucleoside triphosphate (NTP) levels, which could decrease with their antiviral potency. Competition studies were conducted by coincubation of either radiolabeled DFC with different concentrations of 3TC or radiolabeled 3TC with different concentrations of DFC. Coincubation of radiolabeled 3TC with DFC at concentrations up to 33.3 microM did not cause any marked reduction in 3TC-triphosphate (TP) or any 3TC metabolites. However, a reduction in the level of DFC metabolites was noted at high concentrations of 3TC with radiolabeled DFC. DFC-TP levels in CEM and primary human PBM cells decreased by 88% and 94%, respectively, when high concentrations of 3TC (33.3 and 100 microM) were added, which may influence the effectiveness of DFC-5'-TP on the HIV-1 polymerase. The NTP levels remained well above the median (50%) inhibitory concentration for HIV-1 reverse transcriptase. These results suggest that both beta-d- and beta-l-2'-deoxycytidine analogs, DFC and 3TC, respectively, substrates of 2'-deoxycytidine kinase, could be used in a combined therapeutic modality. However, it may be necessary to decrease the dose of 3TC for this combination to prove effective.

  19. Characterization of a ranavirus inhibitor of the antiviral protein kinase PKR

    PubMed Central

    2011-01-01

    Background Ranaviruses (family Iridoviridae) are important pathogens of lower vertebrates. However, little is known about how they circumvent the immune response of their hosts. Many ranaviruses contain a predicted protein, designated vIF2α, which shows homology with the eukaryotic translation initiation factor 2α. In analogy to distantly related proteins found in poxviruses vIF2α might act as an inhibitor of the antiviral protein kinase PKR. Results We have characterized the function of vIF2α from Rana catesbeiana virus Z (RCV-Z). Multiple sequence alignments and secondary structure prediction revealed homology of vIF2α with eIF2α throughout the S1-, helical- and C-terminal domains. Genetic and biochemical analyses showed that vIF2α blocked the toxic effects of human and zebrafish PKR in a heterologous yeast system. Rather than complementing eIF2α function, vIF2α acted in a manner comparable to the vaccinia virus (VACV) K3L protein (K3), a pseudosubstrate inhibitor of PKR. Both vIF2α and K3 inhibited human PKR-mediated eIF2α phosphorylation, but not PKR autophosphorylation on Thr446. In contrast the E3L protein (E3), another poxvirus inhibitor of PKR, inhibited both Thr446 and eIF2α Ser51 phosphorylation. Interestingly, phosphorylation of eIF2α by zebrafish PKR was inhibited by vIF2α and E3, but not by K3. Effective inhibition of PKR activity coincided with increased PKR expression levels, indicative of relieved autoinhibition of PKR expression. Experiments with vIF2α deletion constructs, showed that both the N-terminal and helical domains were sufficient for inhibition of PKR, whereas the C-terminal domain was dispensable. Conclusions Our results show that RCV-Z vIF2α is a functional inhibitor of human and zebrafish PKR, and probably functions in similar fashion as VACV K3. This constitutes an important step in understanding the interaction of ranaviruses and the host innate immune system. PMID:21418572

  20. Host-Targeting Agents to Prevent and Cure Hepatitis C Virus Infection

    PubMed Central

    Zeisel, Mirjam B.; Crouchet, Emilie; Baumert, Thomas F.; Schuster, Catherine

    2015-01-01

    Chronic hepatitis C virus (HCV) infection is a major cause of liver cirrhosis and hepatocellular carcinoma (HCC) which are leading indications of liver transplantation (LT). To date, there is no vaccine to prevent HCV infection and LT is invariably followed by infection of the liver graft. Within the past years, direct-acting antivirals (DAAs) have had a major impact on the management of chronic hepatitis C, which has become a curable disease in the majority of DAA-treated patients. In contrast to DAAs that target viral proteins, host-targeting agents (HTAs) interfere with cellular factors involved in the viral life cycle. By acting through a complementary mechanism of action and by exhibiting a generally higher barrier to resistance, HTAs offer a prospective option to prevent and treat viral resistance. Indeed, given their complementary mechanism of action, HTAs and DAAs can act in a synergistic manner to reduce viral loads. This review summarizes the different classes of HTAs against HCV infection that are in preclinical or clinical development and highlights their potential to prevent HCV infection, e.g., following LT, and to tailor combination treatments to cure chronic HCV infection. PMID:26540069

  1. Ontogeny and water temperature influences the antiviral response of the Pacific oyster, Crassostrea gigas.

    PubMed

    Green, Timothy J; Montagnani, Caroline; Benkendorff, Kirsten; Robinson, Nick; Speck, Peter

    2014-01-01

    Disease is caused by a complex interaction between the pathogen, environment, and the physiological status of the host. Determining how host ontogeny interacts with water temperature to influence the antiviral response of the Pacific oysters, Crassostrea gigas, is a major goal in understanding why juvenile Pacific oysters are dying during summer as a result of the global emergence of a new genotype of the Ostreid herpesvirus, termed OsHV-1 μvar. We measured the effect of temperature (12 vs 22 °C) on the antiviral response of adult and juvenile C. gigas injected with poly I:C. Poly I:C up-regulated the expression of numerous immune genes, including TLR, MyD88, IκB-1, Rel, IRF, MDA5, STING, SOC, PKR, Viperin and Mpeg1. At 22 °C, these immune genes showed significant up-regulation in juvenile and adult oysters, but the majority of these genes were up-regulated 12 h post-injection for juveniles compared to 26 h for adults. At 12 °C, the response of these genes was completely inhibited in juveniles and delayed in adults. Temperature and age had no effect on hemolymph antiviral activity against herpes simplex virus (HSV-1). These results suggest that oysters rely on a cellular response to minimise viral replication, involving recognition of virus-associated molecular patterns to induce host cells into an antiviral state, as opposed to producing broad-spectrum antiviral compounds. This cellular response, measured by antiviral gene expression of circulating hemocytes, was influenced by temperature and oyster age. We speculate whether the vigorous antiviral response of juveniles at 22 °C results in an immune-mediated disorder causing mortality.

  2. Escape Mutations in NS4B Render Dengue Virus Insensitive to the Antiviral Activity of the Paracetamol Metabolite AM404.

    PubMed

    van Cleef, Koen W R; Overheul, Gijs J; Thomassen, Michael C; Marjakangas, Jenni M; van Rij, Ronald P

    2016-04-01

    Despite the enormous disease burden associated with dengue virus infections, a licensed antiviral drug is lacking. Here, we show that the paracetamol (acetaminophen) metabolite AM404 inhibits dengue virus replication. Moreover, we find that mutations in NS4B that were previously found to confer resistance to the antiviral compounds NITD-618 and SDM25N also render dengue virus insensitive to AM404. Our work provides further support for NS4B as a direct or indirect target for antiviral drug development.

  3. In vitro antiviral activity of plant extracts from Asteraceae medicinal plants

    PubMed Central

    2013-01-01

    Background Due to the high prevalence of viral infections having no specific treatment and the constant appearance of resistant viral strains, the development of novel antiviral agents is essential. The aim of this study was to evaluate the antiviral activity against bovine viral diarrhea virus, herpes simplex virus type 1 (HSV-1), poliovirus type 2 (PV-2) and vesicular stomatitis virus of organic (OE) and aqueous extracts (AE) from: Baccharis gaudichaudiana, B. spicata, Bidens subalternans, Pluchea sagittalis, Tagetes minuta and Tessaria absinthioides. A characterization of the antiviral activity of B. gaudichaudiana OE and AE and the bioassay-guided fractionation of the former and isolation of one active compound is also reported. Methods The antiviral activity of the OE and AE of the selected plants was evaluated by reduction of the viral cytopathic effect. Active extracts were then assessed by plaque reduction assays. The antiviral activity of the most active extracts was characterized by evaluating their effect on the pretreatment, the virucidal activity and the effect on the adsorption or post-adsorption period of the viral cycle. The bioassay-guided fractionation of B. gaudichaudiana OE was carried out by column chromatography followed by semipreparative high performance liquid chromatography fractionation of the most active fraction and isolation of an active compound. The antiviral activity of this compound was also evaluated by plaque assay. Results B. gaudichaudiana and B. spicata OE were active against PV-2 and VSV. T. absinthioides OE was only active against PV-2. The corresponding three AE were active against HSV-1. B. gaudichaudiana extracts (OE and AE) were the most selective ones with selectivity index (SI) values of 10.9 (PV-2) and >117 (HSV-1). For this reason, both extracts of B. gaudichaudiana were selected to characterize their antiviral effects. Further bioassay-guided fractionation of B. gaudichaudiana OE led to an active fraction, FC (EC50

  4. Antiviral Activity of Myticin C Peptide from Mussel: an Ancient Defense against Herpesviruses

    PubMed Central

    Romero, Alejandro; Pereiro, Patricia; Costa, María M.; Dios, Sonia; Estepa, Amparo; Parra, Francisco; Figueras, Antonio

    2016-01-01

    ABSTRACT Little is known about the antiviral response in mollusks. As in other invertebrates, the interferon signaling pathways have not been identified, and in fact, there is a debate about whether invertebrates possess antiviral immunity similar to that of vertebrates. In marine bivalves, due to their filtering activity, interaction with putative pathogens, including viruses, is very high, suggesting that they should have mechanisms to address these infections. In this study, we confirmed that constitutively expressed molecules in naive mussels confer resistance in oysters to ostreid herpesvirus 1 (OsHV-1) when oyster hemocytes are incubated with mussel hemolymph. Using a proteomic approach, myticin C peptides were identified in both mussel hemolymph and hemocytes. Myticins, antimicrobial peptides that have been previously characterized, were constitutively expressed in a fraction of mussel hemocytes and showed antiviral activity against OsHV-1, suggesting that these molecules could be responsible for the antiviral activity of mussel hemolymph. For the first time, a molecule from a bivalve has shown antiviral activity against a virus affecting mollusks. Moreover, myticin C peptides showed antiviral activity against human herpes simplex viruses 1 (HSV-1) and 2 (HSV-2). In summary, our work sheds light on the invertebrate antiviral immune response with the identification of a molecule with potential biotechnological applications. IMPORTANCE Several bioactive molecules that have potential pharmaceutical or industrial applications have been identified and isolated from marine invertebrates. Myticin C, an antimicrobial peptide from the Mediterranean mussel (Mytilus galloprovincialis) that was identified by proteomic techniques in both mussel hemolymph and hemocytes, showed potential as an antiviral agent against ostreid herpesvirus 1 (OsHV-1), which represents a major threat to the oyster-farming sector. Both hemolymph from mussels and a myticin C peptide inhibited Os

  5. 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

  6. Induction of IFN-α Subtypes and Their Antiviral Activity in Mumps Virus Infection

    PubMed Central

    Šantak, Maja; Košutić-Gulija, Tanja; Jergović, Mladen; Jug, Renata; Forčić, Dubravko

    2014-01-01

    Abstract Human type I interferons (IFNs) comprise one IFN-β, -ω, -κ, and -ɛ and 12 different IFN-α subtypes, which play an important role in early host antiviral response. Despite their high structural homology and signaling through the same receptor, IFN-α subtypes exhibit different antiviral, antiproliferative, and immunomodulatory activities. Differences in the production of IFN-α subtypes therefore determine the quality of an antiviral response. In this study, we investigated the pattern of IFN-α subtypes induced in infection with different mumps virus (MuV) strains and examined the MuV sensitivity to the action of IFN-α subtypes. We found that all IFN-α subtypes are being expressed in response to MuV infection with a highly similar IFN-α subtype pattern between the virus strains. We assessed an antiviral activity of several IFN-α subtypes: IFN-α1, IFN-α2, IFN-α4, IFN-α6, IFN-α8, IFN-α14, IFN-α17, and IFN-α21. Although they were all effective in suppressing MuV replication, the intensity and pattern of their action varied between MuV strains. Our results indicate that the overall IFN antiviral activity as well as the activity of specific IFN-α subtypes against MuV depend on a virus strain. PMID:25361048

  7. Antiviral Activities of Several Oral Traditional Chinese Medicines against Influenza Viruses

    PubMed Central

    Ma, Lin-Lin; Ge, Miao; Wang, Hui-Qiang; Yin, Jin-Qiu; Jiang, Jian-Dong; Li, Yu-Huan

    2015-01-01

    Influenza is still a serious threat to human health with significant morbidity and mortality. The emergence of drug-resistant influenza viruses poses a great challenge to existing antiviral drugs. Traditional Chinese medicines (TCMs) may be an alternative to overcome the challenge. Here, 10 oral proprietary Chinese medicines were selected to evaluate their anti-influenza activities. These drugs exhibit potent inhibitory effects against influenza A H1N1, influenza A H3N2, and influenza B virus. Importantly, they demonstrate potent antiviral activities against drug-resistant strains. In the study of mechanisms, we found that Xiaoqinglong mixture could increase antiviral interferon production by activating p38 MAPK, JNK/SAPK pathway, and relative nuclear transcription factors. Lastly, our studies also indicate that some of these medicines show inhibitory activities against EV71 and CVB strains. In conclusion, the 10 traditional Chinese medicines, as kind of compound combination medicines, show broad-spectrum antiviral activities, possibly also including inhibitory activities against strains resistant to available antiviral drugs. PMID:26557857

  8. Antiviral activity and mode of action of propolis extracts and selected compounds.

    PubMed

    Schnitzler, Paul; Neuner, Annett; Nolkemper, Silke; Zundel, Christine; Nowack, Hans; Sensch, Karl Heinz; Reichling, Jürgen

    2010-01-01

    Aqueous and ethanol extracts of propolis were analysed phytochemically and examined for their antiviral activity in vitro. Different polyphenols, flavonoids and phenylcarboxylic acids were identified as major constituents. The antiviral effect of propolis extracts and selected constituents, e.g. caffeic acid (1), p-coumaric acid (2), benzoic acid (3), galangin (4), pinocembrin (5) and chrysin (6) against herpes simplex virus type 1 (HSV-1) was analysed in cell culture. The 50% inhibitory concentration (IC(50)) of aqueous and ethanol propolis extracts for HSV-1 plaque formation was determined at 0.0004% and 0.000035%, respectively. Both propolis extracts exhibited high levels of antiviral activity against HSV-1 in viral suspension tests, plaque formation was significantly reduced by >98%. In order to determine the mode of antiviral action of propolis, the extracts were added at different times during the viral infection cycle. Both propolis extracts exhibited high anti-HSV-1 activity when the viruses were pretreated with these drugs prior to infection. Among the analysed compounds, only galangin and chrysin displayed some antiviral activity. However, the extracts containing many different components exhibited significantly higher antiherpetic effects as well as higher selectivity indices than single isolated constituents. Propolis extracts might be suitable for topical application against herpes infection.

  9. 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

  10. 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.

  11. 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.

  12. Oxidative stress correlates with Wolbachia-mediated antiviral