scholarly journals Comparative In Vitro Anti-Hepatitis C Virus Activities of a Selected Series of Polymerase, Protease, and Helicase Inhibitors

2008 ◽  
Vol 52 (9) ◽  
pp. 3433-3437 ◽  
Author(s):  
Jan Paeshuyse ◽  
Inge Vliegen ◽  
Lotte Coelmont ◽  
Pieter Leyssen ◽  
Oriana Tabarrini ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Comparative Study ◽  
Hcv Genotype ◽  
Genotype 1B ◽  
Polymerase Iii ◽  
Ns3 Protease

ABSTRACT We report here a comparative study of the anti-hepatitis C virus (HCV) activities of selected (i) nucleoside polymerase, (ii) nonnucleoside polymerase, (iii) α,γ-diketo acid polymerase, (iv) NS3 protease, and (v) helicase inhibitors, as well as (vi) cyclophilin binding molecules and (vii) alpha 2b interferon in four different HCV genotype 1b replicon systems.

scholarly journals Resistance Analysis of the Hepatitis C Virus NS3 Protease Inhibitor Asunaprevir

2012 ◽  
Vol 56 (7) ◽  
pp. 3670-3681 ◽  
Author(s):  
Fiona McPhee ◽  
Jacques Friborg ◽  
Steven Levine ◽  
Chaoqun Chen ◽  
Paul Falk ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protease Inhibitor ◽  
Clinical Studies ◽  
Replication Capacity ◽  
Replication Complex ◽  
Hcv Genotype ◽  
Genotype 1A ◽  
Genotype 1B ◽  
Ns3 Protease

ABSTRACTAsunaprevir (BMS-650032) is a potent hepatitis C virus (HCV) NS3 protease inhibitor demonstrating efficacy in alfa interferon-sparing, direct-acting antiviral dual-combination regimens (together with the NS5A replication complex inhibitor daclatasvir) in patients chronically infected with HCV genotype 1b. Here, we describe a comprehensivein vitrogenotypic and phenotypic analysis of asunaprevir-associated resistance against genotypes 1a and 1b using HCV replicons and patient samples obtained from clinical studies of short-term asunaprevir monotherapy. During genotype 1a resistance selection using HCV replicons, the primary NS3 protease substitutions identified were R155K, D168G, and I170T, which conferred low- to moderate-level asunaprevir resistance (5- to 21-fold) in transient-transfection susceptibility assays. For genotype 1b, a higher level of asunaprevir-associated resistance was observed at the same selection pressures, ranging from 170- to 400-fold relative to the wild-type control. The primary NS3 protease substitutions identified occurred predominantly at amino acid residue D168 (D168A/G/H/V/Y) and were associated with high-level asunaprevir resistance (16- to 280-fold) and impaired replication capacity. In asunaprevir single-ascending-dose and 3-day multiple-ascending-dose studies in HCV genotype 1a- or 1b-infected patients, the predominant pre-existing NS3 baseline polymorphism was NS3-Q80K. This substitution impacted initial virologic response rates in a single-ascending-dose study, but its effects after multiple doses were more ambiguous. Interestingly, for patient NS3 protease sequences containing Q80 and those containing K80, susceptibilities to asunaprevir were comparable when tested in an enzyme assay. No resistance-associated variants emerged in these clinical studies that significantly impacted susceptibility to asunaprevir. Importantly, asunaprevir-resistant replicons remained susceptible to an NS5A replication complex inhibitor, consistent with a role for asunaprevir in combination therapies.

scholarly journals Development and characterization of a transient-replication assay for the genotype 2a hepatitis C virus subgenomic replicon

2005 ◽  
Vol 86 (11) ◽  
pp. 3075-3080 ◽  
Author(s):  
Paul Targett-Adams ◽  
John McLauchlan
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Osteosarcoma Cell ◽  
Dependent Manner ◽  
Entry Site ◽  
Subgenomic Replicon ◽  
Replication Assay ◽  
Cell Extracts ◽  
Genotype 1B

Dicistronic, subgenomic hepatitis C virus (HCV) replicons were constructed containing sequences from JFH1, a genotype 2a strain, that also incorporated the firefly luciferase gene under the control of the HCV internal ribosome entry site element. Luciferase activity in Huh-7 cell extracts containing in vitro-transcribed subgenomic JFH1 RNA was monitored over a 72 h period to examine early stages of HCV replication in the absence of any selective pressure. Enzyme activities produced by the replicon were almost 200-fold greater than those generated from corresponding genotype 1b replicons and correlated with an accumulation of NS5A protein and replicon RNA. Transient replication was sensitive to IFN treatment in a dose-dependent manner and, in addition to Huh-7 cells, the U2OS human osteosarcoma cell line supported efficient replication of the JFH1 replicon. Thus, this system based on JFH1 sequences offers improvements over prior genotype 1b replicons for quantitative measurement of viral RNA replication.

scholarly journals Hepatitis C Virus NS4B Can Suppress STING Accumulation To Evade Innate Immune Responses

2015 ◽  
Vol 90 (1) ◽  
pp. 254-265 ◽  
Author(s):  
Guanghui Yi ◽  
Yahong Wen ◽  
Chang Shu ◽  
Qingxia Han ◽  
Kouacou V. Konan ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Transmembrane Domain ◽  
Inhibitory Effect ◽  
Type I ◽  
Hcv Genotype ◽  
Type I Ifns ◽  
Genotype 1B ◽  
Jfh1 Virus ◽  
Cyclic Dinucleotide

ABSTRACT The cyclic dinucleotide 2′,3′-cGAMP can bind the adaptor protein STING (stimulator of interferon [IFN] genes) to activate the production of type I IFNs and proinflammatory cytokines. We found that cGAMP added to the culture medium could suppress the replication of the hepatitis C virus (HCV) genotype 1b strain Con1 subgenomic replicon in human hepatoma cells. Knockdown of STING expression diminished the inhibitory effect on replicon replication, while overexpression of STING enhanced the inhibitory effects of cGAMP. The addition of cGAMP into 1b/Con1 replicon cells significantly increased the expression of type I IFNs and antiviral interferon-stimulated genes. Unexpectedly, replication of the genotype 2a JFH1 replicon and infectious JFH1 virus was less sensitive to the inhibitory effect of cGAMP than was that of 1b/Con1 replicon. Using chimeric replicons, 2a NS4B was identified to confer resistance to cGAMP. Transient expression of 2a NS4B resulted in a pronounced inhibitory effect on STING-mediated beta IFN (IFN-β) reporter activation compared to that of 1b NS4B. 2a NS4B was found to suppress STING accumulation in a dose-dependent manner. The predicted transmembrane domain of 2a NS4B was required to inhibit STING accumulation. These results demonstrate a novel genotype-specific inhibition of the STING-mediated host antiviral immune response. IMPORTANCE The cyclic dinucleotide cGAMP was found to potently inhibit the replication of HCV genotype 1b Con1 replicon but was less effective for the 2a/JFH1 replicon and infectious JFH1 virus. The predicted transmembrane domain in 2a NS4B was shown to be responsible for the decreased sensitivity to cGAMP. The N terminus of NS4B has been reported to suppress STING-mediated signaling by disrupting the interaction of STING and TBK1 and/or MAVS. We show that 2a/JFH1 NS4B has an additional mechanism to evade STING signaling through suppressing STING accumulation.

scholarly journals Preclinical Characterization of the Novel Hepatitis C Virus NS3 Protease Inhibitor GS-9451

2013 ◽  
Vol 58 (2) ◽  
pp. 647-653 ◽  
Author(s):  
Huiling Yang ◽  
Margaret Robinson ◽  
Amoreena C. Corsa ◽  
Betty Peng ◽  
Guofeng Cheng ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Activity ◽  
Protease Inhibitor ◽  
Hcv Infection ◽  
Cross Resistance ◽  
Protease Gene ◽  
Ns5a Inhibitor ◽  
Ns3 Protease

ABSTRACTGS-9451 is a selective hepatitis C virus (HCV) NS3 protease inhibitor in development for the treatment of genotype 1 (GT1) HCV infection. Key preclinical properties of GS-9451, includingin vitroantiviral activity, selectivity, cross-resistance, and combination activity, as well as pharmacokinetic properties, were determined. In multiple GT1a and GT1b replicon cell lines, GS-9451 had mean 50% effective concentrations (EC50s) of 13 and 5.4 nM, respectively, with minimal cytotoxicity; similar potency was observed in chimeric replicons encoding the NS3 protease gene of GT1 clinical isolates. GS-9451 was less active in GT2a replicon cells (EC50= 316 nM). Additive to synergisticin vitroantiviral activity was observed when GS-9451 was combined with other agents, including alpha interferon, ribavirin, and the polymerase inhibitors GS-6620 and tegobuvir (GS-9190), as well as the NS5A inhibitor ledipasvir (GS-5885). GS-9451 retained wild-type activity against multiple classes of NS5B and NS5A inhibitor resistance mutations. GS-9451 was stable in hepatic microsomes and hepatocytes from human and three other tested species. Systemic clearance was low in dogs and monkeys but high in rats. GS-9451 showed good oral bioavailability in all three species tested. In rats, GS-9451 levels were ∼40-fold higher in liver than plasma after intravenous dosing, and elimination of GS-9451 was primarily through biliary excretion. Together, these results are consistent with the antiviral activity observed in a recent phase 1b study. The results ofin vitrocross-resistance and combination antiviral assays support the ongoing development of GS-9451 in combination with other agents for the treatment of chronic HCV infection.

scholarly journals A Hepatitis C Virus-Associated Cirrhotic Patient Developing Interstitial Pneumonia during the Course of Antiviral Therapy with Ombitasvir/Paritaprevir/Ritonavir

2017 ◽  
Vol 11 (2) ◽  
pp. 369-376 ◽  
Author(s):  
Kazuo Tarao ◽  
Kouzo Yamada
Keyword(s):  
Computed Tomography ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Interstitial Pneumonia ◽  
Total Duration ◽  
Drug Discontinuation ◽  
Chest Computed Tomography ◽  
Hcv Genotype ◽  
Genotype 1B ◽  
Direct Acting

Oral direct-acting antivirals (DAAs) are the main therapy for hepatitis C virus (HCV)-associated liver disease in Japan. Daclatasvir/asunaprevir is the first agent and sofosbuvir/ledipasvir is the secondary agent for HCV genotype 1b. More recently, ombitasvir/paritaprevir/ritonavir is also recommended as a potent therapy for HCV genotype 1b. Among the adverse events associated with these oral DAAs, interstitial pneumonia is one of the most severe ones. Regarding treatment with daclatasvir plus asunaprevir or sofosbuvir plus ledipasvir, a few cases have already been reported in a postmarketing surveillance. Recently, we have encountered a HCV-associated genotype 1b cirrhosis patient who developed interstitial pneumonia during treatment with ombitasvir/paritaprevir/ritonavir and who recovered after drug discontinuation without corticosteroid therapy. Interstitial pneumonia was confirmed by chest x-ray and chest computed tomography. The serum KL-6 level was elevated to 1,180 U/mL. The total duration of the drug administration was 7 weeks, and she achieved SVR24. This is the first detailed report in the literature on the development of interstitial pneumonia during treatment with ombitasvir/paritaprevir/ritonavir. When dry cough appeared in the treatment with DAAs, chest computed tomography and the evaluation of serum KL-6 level were recommended.

Preclinical Pharmacokinetics and In Vitro Metabolism of Asunaprevir (BMS-650032), a Potent Hepatitis C Virus NS3 Protease Inhibitor

2015 ◽  
Vol 104 (9) ◽  
pp. 2813-2823 ◽  
Author(s):  
Kathleen W. Mosure ◽  
Jay O. Knipe ◽  
Marc Browning ◽  
Vinod Arora ◽  
Yue-Zhong Shu ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protease Inhibitor ◽  
In Vitro Metabolism ◽  
Preclinical Pharmacokinetics ◽  
Ns3 Protease
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