scholarly journals Longer Poly(U) Stretches in the 3′UTR Are Essential for Replication of the Hepatitis C Virus Genotype 4a Clone in in vitro and in vivo

2021 ◽  
Vol 12 ◽  
Author(s):  
Asako Takagi ◽  
Yutaka Amako ◽  
Daisuke Yamane ◽  
Bouchra Kitab ◽  
Yuko Tokunaga ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Infectious Clone ◽  
Post Inoculation ◽  
Chimeric Mouse ◽  
Virus Genotype ◽  
Viral Propagation ◽  
Chronic Hcv

The 3′ untranslated region (UTR) of the hepatitis C virus (HCV) genome plays a significant role in replication including the poly(U) tract (You and Rice, 2008). Here we established an HCV clone that is infectious in vitro and in vivo, from an Egyptian patient with chronic HCV infection and hepatocellular carcinoma (HCC). First, we inoculated the patient plasma into a humanized chimeric mouse and passaged. We observed HCV genotype 4a propagation in the chimeric mouse sera at 1.7 × 107 copies/mL after 6 weeks. Next, we cloned the entire HCV sequence from the HCV-infected chimeric mouse sera using RT-PCR, and 5′ and 3′ RACE methodologies. We obtained first a shorter clone (HCV-G4 KM short, GenBank: AB795432.1), which contained 9,545 nucleotides with 341 nucleotides of the 5′UTR and 177 nucleotides of the 3′UTR, and this was frequently obtained for unknown reasons. We also obtained a longer clone by dividing the HCV genome into three fragments and the poly (U) sequences. We obtained a longer 3′UTR sequence than that of the HCV-G4 KM short clone, which contained 9,617 nucleotides. This longer clone possessed a 3′-UTR of 249 nucleotides (HCV-G4 KM long, GenBank: AB795432.2), because of a 71-nucleotide longer poly (U) stretch. The HCV-G4-KM long clone, but not the HCV-G4-KM short clone, could establish infection in human hepatoma HuH-7 cells. HCV RNAs carrying a nanoluciferase (NL) reporter were also constructed and higher replication activity was observed with G4-KM long-NL in vitro. Next, both short and long RNAs were intra-hepatically injected into humanized chimeric mice. Viral propagation was only observed for the chimeric mouse injected with the HCV-G4 KM long RNA in the sera after 21 days (1.64 × 106 copies/mL) and continued until 10 weeks post inoculation (wpi; 1.45–4.74 × 107 copies/mL). Moreover, sequencing of the HCV genome in mouse sera at 6 wpi revealed the sequence of the HCV-G4-KM long clone. Thus, the in vitro and in vivo results of this study indicate that the sequence of the HCV-G4-KM long RNA is that of an infectious clone.

scholarly journals Characterization of Resistance to the Nonnucleoside NS5B Inhibitor Filibuvir in Hepatitis C Virus-Infected Patients

2011 ◽  
Vol 56 (3) ◽  
pp. 1331-1341 ◽  
Author(s):  
Philip J. F. Troke ◽  
Marilyn Lewis ◽  
Paul Simpson ◽  
Katrina Gore ◽  
Jennifer Hammond ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Site Directed Mutagenesis ◽  
Phenotypic Resistance ◽  
Number Of Patients ◽  
Chronic Hcv ◽  
Selection Of

ABSTRACTFilibuvir (PF-00868554) is an investigational nonnucleoside inhibitor of the hepatitis C virus (HCV) nonstructural 5B (NS5B) RNA-dependent RNA polymerase currently in development for treating chronic HCV infection. The aim of this study was to characterize the selection of filibuvir-resistant variants in HCV-infected individuals receiving filibuvir as short (3- to 10-day) monotherapy. We identified amino acid M423 as the primary site of mutation arising upon filibuvir dosing. Through bulk cloning of clinical NS5B sequences into a transient-replicon system, and supported by site-directed mutagenesis of the Con1 replicon, we confirmed that mutations M423I/T/V mediate phenotypic resistance. Selection in patients of an NS5B mutation at M423 was associated with a reduced replicative capacityin vitrorelative to the pretherapy sequence; consistent with this, reversion to wild-type M423 was observed in the majority of patients following therapy cessation. Mutations at NS5B residues R422 and M426 were detected in a small number of patients at baseline or the end of therapy and also mediate reductions in filibuvir susceptibility, suggesting these are rare but clinically relevant alternative resistance pathways. Amino acid variants at position M423 in HCV NS5B polymerase are the preferred pathway for selection of viral resistance to filibuvirin vivo.

Circulating and inducible IL-32α in chronic hepatitis C virus infection

2019 ◽  
Vol 2 (1) ◽  
pp. 23-30
Author(s):  
Mark Collister ◽  
Julia Rempel ◽  
Jiaqi Yang ◽  
Kelly Kaita ◽  
Zach Raizman ◽  
...  
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Chronic Hepatitis C ◽  
Mononuclear Cells ◽  
Peripheral Blood Mononuclear ◽  
Chronic Hepatitis C Virus ◽  
Chronic Hcv

Background: Interleukin 32 (IL-32) is a recently described pro-inflammatory cytokine implicated in chronic hepatitis C virus (HCV)-related inflammation and fibrosis. IL-32α is the most abundant IL-32 isoform. Methods: Circulating IL-32α levels were documented in patients with chronic HCV infections ( n = 31) and compared with individuals who spontaneously resolved HCV infection ( n = 14) and HCV-naive controls ( n = 20). In addition, peripheral blood mononuclear cells (PBMC) from the chronic HCV ( n = 12) and HCV-naive ( n = 9) cohorts were investigated for responses to HCV core and non-structural (NS)3 protein induced IL-32α production. Finally, correlations between IL-32α levels, hepatic fibrosis and subsequent responses to interferon-based therapy were documented in patients with chronic HCV. Results: Circulating IL-32α levels in patients with chronic HCV were similar to those of spontaneously resolved and HCV-naive controls. HCV protein induced IL-32α responses were similar in chronic HCV patients and HCV-naive controls. In patients with chronic HCV, serum IL-32α levels correlated with worsening METAVIR fibrosis (F) scores from F0 to F3 ( r = 0.596, P < 0.001) as did NS3 induced IL-32α responses ( r = 0.837, P < 0.05). However, these correlations were not sustained with the inclusion of IL-32α levels at F4 scores, suggesting events at F4 interfere with IL-32α synthesis or release. In chronic HCV patients who underwent treatment ( n = 28), baseline in vivo and in vitro induced IL-32α concentrations were not predictive of therapeutic outcomes. Conclusions: IL-32α activity is associated with worsening fibrosis scores in non-cirrhotic, chronic HCV patients.

scholarly journals Preclinical Characterization and Human Microdose Pharmacokinetics of ITMN-8187, a Nonmacrocyclic Inhibitor of the Hepatitis C Virus NS3 Protease

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Ravi Rajagopalan ◽  
Lin Pan ◽  
Caralee Schaefer ◽  
John Nicholas ◽  
Sharlene Lim ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Oral Absorption ◽  
Antiviral Agents ◽  
Hcv Infection ◽  
Chimeric Mouse ◽  
Elimination Kinetics ◽  
Half Maximal Effective Concentration ◽  
Chronic Hcv

Abstract The current paradigm for the treatment of chronic hepatitis C virus (HCV) infection involves combinations of agents that act directly on steps of the HCV life cycle. Here we report the preclinical characteristics of ITMN-8187, a nonmacrocyclic inhibitor of the NS3/4A HCV protease. X-ray crystallographic studies of ITMN-8187 and simeprevir binding to NS3/4A protease demonstrated good agreement between structures. Low nanomolar biochemical potency was maintained against NS3/4A derived from HCV genotypes 1, 2b, 4, 5, and 6. In cell-based potency assays, half-maximal reduction of genotype 1a and 1b HCV replicon RNA was afforded by 11 and 4 nM doses of ITMN-8187, respectively. Combinations of ITMN-8187 with other directly acting antiviral agents in vitro displayed additive antiviral efficacy. A 30-mg/kg of body weight dose of ITMN-8187 administered for 4 days yielded significant viral load reductions through day 5 in a chimeric mouse model of HCV. A 3-mg/kg oral dose administered to rats, dogs, or monkeys yielded concentrations in plasma 16 h after dosing that exceeded the half-maximal effective concentration of ITMN-8187. Human microdose pharmacokinetics showed low intersubject variability and prolonged oral absorption with first-order elimination kinetics compatible with once-daily dosing. These preclinical characteristics compare favorably with those of other NS3/4A inhibitors approved for the treatment of chronic HCV infection.

scholarly journals In VitroCharacterization of the Activity of PF-05095808, a Novel Biological Agent for Hepatitis C Virus Therapy

2011 ◽  
Vol 56 (3) ◽  
pp. 1364-1375 ◽  
Author(s):  
Helen Lavender ◽  
Kevin Brady ◽  
Frances Burden ◽  
Oona Delpuech-Adams ◽  
Hubert Denise ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rna Interference ◽  
Antiviral Activity ◽  
Therapeutic Potential ◽  
Biological Agent ◽  
Small Interfering Rnas ◽  
Chronic Hcv

ABSTRACTPF-05095808 is a novel biological agent for chronic hepatitis C virus (HCV) therapy. It comprises a recombinant adeno-associated virus (AAV) DNA vector packaged into an AAV serotype 8 capsid. The vector directs expression of three short hairpin RNAs (shRNAs) targeted to conserved regions of the HCV genome. These shRNAs are processed by the host cell into the small interfering RNAs which mediate sequence-specific cleavage of target regions. For small-molecule inhibitors the key screens needed to assessin vitroactivity are well defined; we developed new assays to assess this RNA interference agent and so to understand its therapeutic potential. Following administration of PF-05095808 or corresponding synthetic shRNAs, sequence-specific antiviral activity was observed in HCV replicon and infectious virus systems. To quantify the numbers of shRNA molecules required for antiviral activityin vitroand potentially alsoin vivo, a universal quantitative PCR (qPCR) assay was developed. The number of shRNA molecules needed to drive antiviral activity proved to be independent of the vector delivery system used for PF-05095808 administration. The emergence of resistant variants at the target site of one shRNA was characterized. A novel RNA cleavage assay was developed to confirm the spectrum of activity of PF-05095808 against common HCV clinical isolates. In summary, our data both support antiviral activity consistent with an RNA interference mechanism and demonstrate the potential of PF-05095808 as a therapeutic agent for chronic HCV infection.

scholarly journals Mechanisms of Hepatitis C Virus Escape from Vaccine-Relevant Neutralizing Antibodies

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 291
Author(s):  
Rodrigo Velázquez-Moctezuma ◽  
Elias H. Augestad ◽  
Matteo Castelli ◽  
Christina Holmboe Olesen ◽  
Nicola Clementi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Cell Vaccine ◽  
Special Focus ◽  
Direct Modification ◽  
Chronic Hcv

Hepatitis C virus (HCV) is a major causative agent of acute and chronic hepatitis. It is estimated that 400,000 people die every year from chronic HCV infection, mostly from severe liver-related diseases such as cirrhosis and liver cancer. Although HCV was discovered more than 30 years ago, an efficient prophylactic vaccine is still missing. The HCV glycoprotein complex, E1/E2, is the principal target of neutralizing antibodies (NAbs) and, thus, is an attractive antigen for B-cell vaccine design. However, the high genetic variability of the virus necessitates the identification of conserved epitopes. Moreover, the high intrinsic mutational capacity of HCV allows the virus to continually escape broadly NAbs (bNAbs), which is likely to cause issues with vaccine-resistant variants. Several studies have assessed the barrier-to-resistance of vaccine-relevant bNAbs in vivo and in vitro. Interestingly, recent studies have suggested that escape substitutions can confer antibody resistance not only by direct modification of the epitope but indirectly through allosteric effects, which can be grouped based on the breadth of these effects on antibody susceptibility. In this review, we summarize the current understanding of HCV-specific NAbs, with a special focus on vaccine-relevant bNAbs and their targets. We highlight antibody escape studies pointing out the different methodologies and the escape mutations identified thus far. Finally, we analyze the antibody escape mechanisms of envelope protein escape substitutions and polymorphisms according to the most recent evidence in the HCV field. The accumulated knowledge in identifying bNAb epitopes as well as assessing barriers to resistance and elucidating relevant escape mechanisms may prove critical in the successful development of an HCV B-cell vaccine.

scholarly journals Natural Killer Cell Function and Dysfunction in Hepatitis C Virus Infection

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Kayla A. Holder ◽  
Rodney S. Russell ◽  
Michael D. Grant
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Natural Killer ◽  
Nk Cell ◽  
Hcv Infection ◽  
Host Immune System ◽  
Chronic Hcv Infection ◽  
Chronic Hcv

Viruses must continually adapt against dynamic innate and adaptive responses of the host immune system to establish chronic infection. Only a small minority (~20%) of those exposed to hepatitis C virus (HCV) spontaneously clear infection, leaving approximately 200 million people worldwide chronically infected with HCV. A number of recent research studies suggest that establishment and maintenance of chronic HCV infection involve natural killer (NK) cell dysfunction. This relationship is illustratedin vitroby disruption of typical NK cell responses including both cell-mediated cytotoxicity and cytokine production. Expression of a number of activating NK cell receptorsin vivois also affected in chronic HCV infection. Thus, directin vivoandin vitroevidence of compromised NK function in chronic HCV infection in conjunction with significant epidemiological associations between the outcome of HCV infection and certain combinations of NK cell regulatory receptor and class I human histocompatibility linked antigen (HLA) genotypes indicate that NK cells are important in the immune response against HCV infection. In this review, we highlight evidence suggesting that selective impairment of NK cell activity is related to establishment of chronic HCV infection.

scholarly journals A chimeric GB virus B encoding the hepatitis C virus hypervariable region 1 is infectious in vivo

2007 ◽  
Vol 88 (3) ◽  
pp. 895-902 ◽  
Author(s):  
G. Haqshenas ◽  
X. Dong ◽  
H. Netter ◽  
J. Torresi ◽  
E. J. Gowans
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hypervariable Region ◽  
Immunoblot Analysis ◽  
Post Inoculation ◽  
Sequencing Analysis ◽  
Coding Region ◽  
Hypervariable Region 1

Two GB virus B (GBV-B) chimeric genomes, GBV-HVR and GBV-HVRh (with a hinge), containing the coding region of the immunodominant hypervariable region 1 (HVR1) of the E2 envelope protein of Hepatitis C virus (HCV) were constructed. Immunoblot analysis confirmed that HVR1 was anchored to the GBV-B E2 protein. To investigate the replication competence and in vivo stability of in vitro-generated chimeric RNA transcripts, two naïve marmosets were inoculated intrahepatically with the transcripts. The GBV-HVR chimeric genome was detectable for 2 weeks post-inoculation (p.i.), whereas GBV-HVRh reverted to wild type 1 week p.i. Sequencing analysis of the HVR1 and flanking regions from GBV-HVR RNA isolated from marmoset serum demonstrated that the HVR1 insert remained unaltered in the GBV-HVR chimera for 2 weeks. Inoculation of a naïve marmoset with serum collected at 1 week p.i. also resulted in viraemia and confirmed that the serum contained infectious particles. All animals cleared the infection by 3 weeks p.i. and remained negative for the remaining weeks. The chimera may prove useful for the in vivo examination of any HCV HVR1-based vaccine candidates.

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

scholarly journals Mass Balance, Metabolite Profile, andIn Vitro-In VivoComparison of Clearance Pathways of Deleobuvir, a Hepatitis C Virus Polymerase Inhibitor

2014 ◽  
Vol 59 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Lin-Zhi Chen ◽  
John P. Sabo ◽  
Elsy Philip ◽  
Lois Rowland ◽  
Yan Mao ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Mass Balance ◽  
Metabolite Profile ◽  
Fecal Samples ◽  
Acyl Glucuronide ◽  
Polymerase Inhibitor ◽  
Main Components

ABSTRACTThe pharmacokinetics, mass balance, and metabolism of deleobuvir, a hepatitis C virus (HCV) polymerase inhibitor, were assessed in healthy subjects following a single oral dose of 800 mg of [14C]deleobuvir (100 μCi). The overall recovery of radioactivity was 95.2%, with 95.1% recovered from feces. Deleobuvir had moderate to high clearance, and the half-life of deleobuvir and radioactivity in plasma were ∼3 h, indicating that there were no metabolites with half-lives significantly longer than that of the parent. The most frequently reported adverse events (in 6 of 12 subjects) were gastrointestinal disorders. Two major metabolites of deleobuvir were identified in plasma: an acyl glucuronide and an alkene reduction metabolite formed in the gastrointestinal (GI) tract by gut bacteria (CD 6168), representing ∼20% and 15% of the total drug-related material, respectively. Deleobuvir and CD 6168 were the main components in the fecal samples, each representing ∼30 to 35% of the dose. The majority of the remaining radioactivity found in the fecal samples (∼21% of the dose) was accounted for by three metabolites in which deleobuvir underwent both alkene reduction and monohydroxylation. In fresh human hepatocytes that form biliary canaliculi in sandwich cultures, the biliary excretion for these excretory metabolites was markedly higher than that for deleobuvir and CD 6168, implying that rapid biliary elimination upon hepatic formation may underlie the absence of these metabolites in circulation. The lowin vitroclearance was not predictive of the observedin vivoclearance, likely because major deleobuvir biotransformation occurred by non-CYP450-mediated enzymes that are not well represented in hepatocyte-basedin vitromodels.

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