scholarly journals Development of a GB Virus B Marmoset Model and Its Validation with a Novel Series of Hepatitis C Virus NS3 Protease Inhibitors

2004 ◽  
Vol 78 (4) ◽  
pp. 2062-2071 ◽  
Author(s):  
Helen Bright ◽  
Anthony R. Carroll ◽  
Paul A. Watts ◽  
Robert J. Fenton
Keyword(s):  
Animal Model ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Common Marmoset ◽  
Infected Hepatocyte ◽  
Molecule Inhibitor ◽  
Days Of Therapy ◽  
Development And Validation ◽  
Ns3 Protease

ABSTRACT GB virus B (GBV-B), a flavivirus closely related to HCV, has previously been shown to infect and replicate to high titers in tamarins (Saguinus sp.). This study describes the use of GBV-B infection and replication in the common marmoset (Callithrix jacchus) for the successful development and validation of a surrogate animal model for hepatitis C virus (HCV). Infection of marmosets with GBV-B produced a viremia that peaked at 108 to 109 genome copies/ml for a period of 40 to 60 days followed by viral clearance at 60 to 80 days postinfection. Passage of the initial tamarin-derived GBV-B in marmosets produced an infectious stock that gave a more reproducible and consistent infection in the marmoset. Titration of the virus stocks in vivo indicated that they contained 1 infectious unit for every 1,000 genome copies. Cultures of primary marmoset hepatocytes were also successfully infected with GBV-B, with high levels of virus detected in supernatants and cells for up to 14 days postinfection. Treatment of GBV-B-infected hepatocyte cultures with a novel class of HCV protease inhibitor (pyrrolidine 5,5 trans-lactams) reduced viral levels by more than 2 logs. Treatment of GBV-B-infected marmosets with one such inhibitor resulted in a 3-log drop in serum viral titer over 4 days of therapy. These studies provide the first demonstration of the in vivo efficacy of a small-molecule inhibitor for HCV in an animal model and illustrate the utility of GBV-B as a surrogate animal model system for HCV.

scholarly journals Preclinical Characterization of BMS-791325, an Allosteric Inhibitor of Hepatitis C Virus NS5B Polymerase

2014 ◽  
Vol 58 (6) ◽  
pp. 3485-3495 ◽  
Author(s):  
Julie A. Lemm ◽  
Mengping Liu ◽  
Robert G. Gentles ◽  
Min Ding ◽  
Stacey Voss ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nucleoside Analogs ◽  
Synergistic Activity ◽  
Genotype 1 ◽  
Allosteric Inhibitor ◽  
Genotype 2 ◽  
Hcv Genotype 1 ◽  
Ns3 Protease

ABSTRACTBMS-791325 is an allosteric inhibitor that binds to thumb site 1 of the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase. BMS-791325 inhibits recombinant NS5B proteins from HCV genotypes 1, 3, 4, and 5 at 50% inhibitory concentrations (IC50) below 28 nM. In cell culture, BMS-791325 inhibited replication of HCV subgenomic replicons representing genotypes 1a and 1b at 50% effective concentrations (EC50s) of 3 nM and 6 nM, respectively, with similar (3 to 18 nM) values for genotypes 3a, 4a, and 5a. Potency against genotype 6a showed more variability (9 to 125 nM), and activity was weaker against genotype 2 (EC50, 87 to 925 nM). Specificity was demonstrated by the absence of activity (EC50s of >4 μM) against a panel of mammalian viruses, and cytotoxic concentrations (50%) were >3,000-fold above the HCV EC50. Resistance substitutions selected by BMS-791325 in genotype 1 replicons mostly mapped to a single site, NS5B amino acid 495 (P495A/S/L/T). Additive or synergistic activity was observed in combination studies using BMS-791325 with alfa interferon plus ribavirin, inhibitors of NS3 protease or NS5A, and other classes of NS5B inhibitor (palm site 2-binding or nucleoside analogs). Plasma and liver exposuresin vivoin several animal species indicated that BMS-791325 has a hepatotropic disposition (liver-to-plasma ratios ranging from 1.6- to 60-fold across species). Twenty-four hours postdose, liver exposures across all species tested were ≥10-fold above the inhibitor EC50s observed with HCV genotype 1 replicons. These findings support the evaluation of BMS-791325 in combination regimens for the treatment of HCV. Phase 3 studies are ongoing.

scholarly journals Expanding the Host Range of Hepatitis C Virus through Viral Adaptation

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Markus von Schaewen ◽  
Marcus Dorner ◽  
Kathrin Hueging ◽  
Lander Foquet ◽  
Sherif Gerges ◽  
...  
Keyword(s):  
Animal Model ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Viral Envelope ◽  
Hcv Infection ◽  
Type I ◽  
Viral Adaptation ◽  
Mouse Hepatocytes

ABSTRACTHepatitis C virus (HCV) species tropism is incompletely understood. We have previously shown that at the level of entry, human CD81 and occludin (OCLN) comprise the minimal set of human factors needed for viral uptake into murine cells. As an alternative approach to genetic humanization, species barriers can be overcome by adapting HCV to use the murine orthologues of these entry factors. We previously generated a murine tropic HCV (mtHCV or Jc1/mCD81) strain harboring three mutations within the viral envelope proteins that allowed productive entry into mouse cell lines. In this study, we aimed to characterize the ability of mtHCV to enter and infect mouse hepatocytesin vivoandin vitro. Using a highly sensitive, Cre-activatable reporter, we demonstrate that mtHCV can enter mouse hepatocytesin vivoin the absence of any human cofactors. Viral entry still relied on expression of mouse CD81 and SCARB1 and was more efficient when mouse CD81 and OCLN were overexpressed. HCV entry could be significantly reduced in the presence of anti-HCV E2 specific antibodies, suggesting that uptake of mtHCV is dependent on viral glycoproteins. Despite mtHCV’s ability to enter murine hepatocytesin vivo, we did not observe persistent infection, even in animals with severely blunted type I and III interferon signaling and impaired adaptive immune responses. Altogether, these results establish proof of concept that the barriers limiting HCV species tropism can be overcome by viral adaptation. However, additional viral adaptations will likely be needed to increase the robustness of a murine model system for hepatitis C.IMPORTANCEAt least 150 million individuals are chronically infected with HCV and are at risk of developing serious liver disease. Despite the advent of effective antiviral therapy, the frequency of chronic carriers has only marginally decreased. A major roadblock in developing a vaccine that would prevent transmission is the scarcity of animal models that are susceptible to HCV infection. It is poorly understood why HCV infects only humans and chimpanzees. To develop an animal model for hepatitis C, previous efforts focused on modifying the host environment of mice, for example, to render them more susceptible to HCV infection. Here, we attempted a complementary approach in which a laboratory-derived HCV variant was tested for its ability to infect mice. We demonstrate that this engineered HCV strain can enter mouse liver cells but does not replicate efficiently. Thus, additional adaptations are likely needed to construct a robust animal model for HCV.

In Vivo Determination of Substrate Specificity of Hepatitis C Virus NS3 Protease: Genetic Assay for Site-Specific Proteolysis

2000 ◽  
Vol 284 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Sung Yun Kim ◽  
Kye Won Park ◽  
Yong Jae Lee ◽  
Sung Hoon Back ◽  
Jae Hwan Goo ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Substrate Specificity ◽  
Site Specific ◽  
Ns3 Protease ◽  
Genetic Assay

scholarly journals Susceptibility of Treatment-Naive Hepatitis C Virus (HCV) Clinical Isolates to HCV Protease Inhibitors

2010 ◽  
Vol 54 (12) ◽  
pp. 5288-5297 ◽  
Author(s):  
Andrew Bae ◽  
Siu-Chi Sun ◽  
Xiaoping Qi ◽  
Xiaowu Chen ◽  
Karin Ku ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protease Inhibitors ◽  
Natural Variation ◽  
Clinical Isolates ◽  
Replication Assay ◽  
Treatment Naïve ◽  
Transient Replication Assay ◽  
Ns3 Protease

ABSTRACT In order to assess the natural variation in susceptibility to hepatitis C virus (HCV) NS3 protease inhibitors (PIs) among untreated HCV patient samples, the susceptibilities of 39 baseline clinical isolates were determined using a transient-replication assay on a panel of HCV PIs, including two α-ketoamides (VX-950 and SCH-503034) and three macrocyclic inhibitors (MK-7009, ITMN-191, and TMC-435350). Some natural variation in susceptibility to all HCV PIs tested was observed among the baseline clinical isolates. The susceptibility to VX-950 correlated strongly with the susceptibility to SCH-503034. A moderate correlation was observed between the susceptibilities to ITMN-191 and MK-7009. In contrast, the phenotypic correlations between the α-ketoamides and macrocyclic inhibitors were significantly lower. This difference is partly attributable to reduced susceptibility of the HCV variants containing the NS3 polymorphism Q80K (existing in 47% of genotype 1a isolates) to the macrocyclic compounds but no change in the sensitivity of the same variants to the α-ketoamides tested. Our results suggest that the natural variation in baseline susceptibility may contribute to different degrees of antiviral response among patients in vivo, particularly at lower doses.

Funktion von CEACAM-1 im Rahmen der Therapie der Hepatitis C-Virus Infektion mit Interferon-alpha in vivo und in vitro

2006 ◽  
Vol 44 (08) ◽  
Author(s):  
P Hilgard ◽  
R Bröring ◽  
M Trippler ◽  
S Viazov ◽  
G Gerken ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Interferon Alpha
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