The hepatitis C virus NS5A protein and response to interferon α: mutational analyses in patients with chronic HCV genotype 3a infection from India

Hepatitis C Virus (HCV) is a flavivirus responsible for causing chronic liver diseases including cirrhosis and hepatocellular carcinoma. Identification of various patient and virus-related factors that can help predict response to antiviral therapy is extremely important in formulating the best therapeutic strategy for each patient either to continue or stop the therapy. The present study aimed to determine Sustained Virological Response (SVR) in HCV genotype 3a infected patients that received combination therapy of Sofosbuvir and Ribavirin and to investigate various factors that can help predict SVR. Study Design: Longitudinal Study Settings: Institute of basic Medical Sciences, Khyber Medical University, Peshawar (IBMS, KMU). Period: July 2016 to September 2017. Materials and Methods: Treatment response was evaluated among 100 HCV genotype 3a infected patients that received Sofosbuvir and Ribavirin therapy for 24 weeks. Various baseline parameters including hematological, biochemical and viral profiles of were recorded. HCV genotype determination was carried out by type specific nested PCR based genotyping assay. Viral load was determined at baseline, at 12 weeks for Early Virological Response (EVR) and at 24 weeks of treatment for SVR. Viral RNA quantification was carried out by Real Time PCR. Results: Out of 100 patients, SVR was observed in 83% of patients; while 17% of the chronic HCV 3a infected patients were Non-Responders (NR). Mean age of patients was low 34 ± 9.8 among patients who achieved SVR as compared to patients with non-response (41 ± 10). The 24 weeks Alanine aminotransferase (ALT) levels were significantly lower among patients with SVR (p-value ≤ 0.05). Although statistically not significant, baseline viral load was higher in NR group (p-value ≥ 0.05), than those with SVR. Association of EVR with SVR was found statistically significant (OR= 2.8, 95% CI 1.2-6.4, p-value ≤ 0.05). Conclusions: The current study indicated that pre and on-treatment monitoring of patients receiving anti-viral therapy is important for the management of patients with chronic HCV infection.

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Mutations Identified in the Hepatitis C Virus (HCV) Polymerase of Patients with Chronic HCV Treated with Ribavirin Cause Resistance and Affect Viral Replication Fidelity

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01417-20 ◽

2020 ◽

Vol 64 (12) ◽

Author(s):

Niels Mejer ◽

Ulrik Fahnøe ◽

Andrea Galli ◽

Santseharay Ramirez ◽

Ola Weiland ◽

...

Keyword(s):

Cell Culture ◽

Chronic Hepatitis ◽

Hepatitis C Virus ◽

Hepatitis C ◽

Chronic Hepatitis C ◽

Prolonged Exposure ◽

Resistance Mutations ◽

Entry Site ◽

Chronic Hcv ◽

Genotype 3A

ABSTRACT Ribavirin has been used for 25 years to treat patients with chronic hepatitis C virus (HCV) infection; however, its antiviral mechanism of action remains unclear. Here, we studied virus evolution in a subset of samples from a randomized 24-week trial of ribavirin monotherapy versus placebo in chronic HCV patients, as well as the viral resistance mechanisms of the observed ribavirin-associated mutations in cell culture. Thus, we performed next-generation sequencing of the full-length coding sequences of HCV recovered from patients at weeks 0, 12, 20, 32 and 40 and analyzed novel single nucleotide polymorphisms (SNPs), diversity, and mutation-linkage. At week 20, increased genetic diversity was observed in 5 ribavirin-treated compared to 4 placebo-treated HCV patients due to new synonymous SNPs, particularly G-to-A and C-to-U ribavirin-associated transitions. Moreover, emergence of 14 nonsynonymous SNPs in HCV nonstructural 5B (NS5B) occurred in treated patients, but not in placebo controls. Most substitutions located close to the NS5B polymerase nucleotide entry site. Linkage analysis showed that putative resistance mutations were found in the majority of genomes in ribavirin-treated patients. Identified NS5B mutations from genotype 3a patients were further introduced into the genotype 3a cell-culture-adapted DBN strain for studies in Huh7.5 cells. Specific NS5B substitutions, including DBN-D148N+I363V, DBN-A150V+I363V, and DBN-T227S+S183P, conferred resistance to ribavirin in long-term cell culture treatment, possibly by reducing the HCV polymerase error rate. In conclusion, prolonged exposure of HCV to ribavirin in chronic hepatitis C patients induces NS5B resistance mutations leading to increased polymerase fidelity, which could be one mechanism for ribavirin resistance.

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Hepatitis C virus (HCV) NS5A protein: role in HCV replication and resistance to interferon‐α

Journal of Viral Hepatitis ◽

10.1046/j.1365-2893.1999.00004.x ◽

1999 ◽

Vol 6 (s1) ◽

pp. 47-48 ◽

Cited By ~ 15

Author(s):

J.‐M. Pawlotsky

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Interferon Α ◽

Ns5a Protein

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Development of full-length cell-culture infectious clone and subgenomic replicon for a genotype 3a isolate of hepatitis C virus

Journal of General Virology ◽

10.1099/jgv.0.001704 ◽

2021 ◽

Vol 102 (12) ◽

Author(s):

Mingxiao Chen ◽

Yi Xu ◽

Ni Li ◽

Ping Yin ◽

Qing Zhou ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Infectious Clone ◽

Virus Production ◽

Full Length ◽

Genotype 3 ◽

Subgenomic Replicon ◽

Hcv Genotype ◽

Hcv Genotype 3 ◽

Genotype 3A

Hepatitis C virus (HCV) genotype 3 is widely distributed, and genotype 3-infected patients achieve a lower cure rate in direct-acting antiviral (DAA) therapy and are associated with a higher risk of hepatic steatosis than patients with other genotypes. Thus, the study of the virology and pathogenesis of genotype 3 HCV is increasingly relevant. Here, we developed a full-length infectious clone and a subgenomic replicon for the genotype 3a isolate, CH3a. From an infected serum, we constructed a full-length CH3a clone, however, it was nonviable in Huh7.5.1 cells. Next, we systematically adapted several intergenotypic recombinants containing Core-NS2 and 5′UTR-NS5A from CH3a, and other sequences from a replication-competent genotype 2 a clone JFH1. Adaptive mutations were identified, of which several combinations facilitated the replication of CH3a-JFH1 recombinants; however, they failed to adapt to the full-length CH3a and the recombinants containing CH3a NS5B. Thus, we attempted to separately adapt CH3a NS5B-3′UTR by constructing an intragenotypic recombinant using 5′UTR-NS5A from an infectious genotype 3a clone, DBN3acc, from which L3004P/M in NS5B and a deletion of 11 nucleotides (Δ11nt) downstream of the polyU/UC tract of the 3′UTR were identified and demonstrated to efficiently improve virus production. Finally, we combined functional 5′UTR-NS5A and NS5B-3′UTR sequences that carried the selected mutations to generate full-length CH3a with 26 or 27 substitutions (CH3acc), and both revealed efficient replication and virus spread in transfected and infected cells, releasing HCV of 104.2 f.f.u. ml−1. CH3acc was inhibited by DAAs targeting NS3/4A, NS5A and NS5B in a dose-dependent manner. The selected mutations permitted the development of subgenomic replicon CH3a-SGRep, by which L3004P, L3004M and Δ11nt were proven, together with a single-cycle virus production assay, to facilitate virus assembly, release, and RNA replication. CH3acc clones and CH3a-SGRep replicon provide new tools for the study of HCV genotype 3.

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Influence of Hepatitis C Virus (HCV) Genotype, HCV RNA Load, and Alanine Aminotransferase Level on Reduction of HCV RNA after a Single Administration of Interferon‐α

The Journal of Infectious Diseases ◽

10.1086/314990 ◽

1999 ◽

Vol 180 (4) ◽

pp. 1411-1412 ◽

Cited By ~ 3

Author(s):

Guido Antonelli ◽

Elisabetta Riva ◽

Fabrizio Maggi ◽

Maria Linda Vatteroni ◽

Eleonora Simeoni

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Alanine Aminotransferase ◽

Aminotransferase Level ◽

Interferon Α ◽

Hcv Rna ◽

Single Administration ◽

Hcv Genotype ◽

Alanine Aminotransferase Level

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New Therapies for Hepatitis C Virus

PRILOZI ◽

10.1515/prilozi-2015-0060 ◽

2015 ◽

Vol 36 (2) ◽

pp. 119-132

Author(s):

Hari Polenakovik

Keyword(s):

Hepatocellular Carcinoma ◽

Hepatitis C Virus ◽

Hepatitis C ◽

Etiologic Agent ◽

Hcv Infection ◽

Interferon Α ◽

Risk Of Death ◽

Duration Of Therapy ◽

Chronic Hcv Infection ◽

Chronic Hcv

Abstract Hepatitis C virus (HCV), the major etiologic agent of "non-A, non-B hepatitis" was discovered 26 years ago. Even before its discovery, interferon-α (IFN) was already being used for treatment of this infection. The next two decades saw a series of incremental improvements of the IFN therapies by extending the duration of therapy, using IFN in combination with oral ribavirin, using pegylated IFN with ribavirin, and most recently adding oral compounds that inhibit the HCV replication (directly acting antivirals - DAAs) to that regimen. DAAs target multiple steps in the HCV life cycle and are now used in combination to treat HCV infection without the need of IFN. These IFN-free, oral DAAs regimens are highly efficacious, have minimal toxicity and are given for short duration. Approved DAAs can cure more then 90% of persons with chronic HCV infection, thereby reducing the risk of death from cirrhosis and hepatocellular carcinoma. However, these drugs are very expensive, and currently their exorbitant cost significantly restricts the access to this therapy for many HCV infected patients.

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Effect of Killer Immunoglobulin-Like Receptors in the Response to Combined Treatment in Patients with Chronic Hepatitis C Virus Infection

Journal of Virology ◽

10.1128/jvi.01285-09 ◽

2009 ◽

Vol 84 (1) ◽

pp. 475-481 ◽

Cited By ~ 59

Author(s):

J. R. Vidal-Castiñeira ◽

A. López-Vázquez ◽

R. Díaz-Peña ◽

R. Alonso-Arias ◽

J. Martínez-Borra ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Combined Treatment ◽

Hla Class I ◽

Response To Treatment ◽

Hcv Rna ◽

Hcv Genotype ◽

Kir Genes ◽

Chronic Hcv Infection ◽

Chronic Hcv

ABSTRACT Killer immunoglobulin-like receptors (KIRs) are related to the activation and inhibition of NK cells and may play an important role in the innate response against infection with viruses such as hepatitis C virus (HCV). We examined whether the different combinations of KIRs with their HLA class I ligands influenced the response to combined treatment (pegylated alpha interferon and ribavirin) of patients infected by HCV. A total of 186 consecutive patients diagnosed with chronic HCV infection were analyzed. Seventy-seven patients exhibited HCV RNA levels at 6 months posttreatment and were called nonresponders (NR), while 109 cleared viral RNA and were named sustained viral responders (SVR). Patients were typed for HLA-B, HLA-Cw, KIR genes, and HCV genotype. In our study, the frequency of the KIR2DL2 allele was significantly increased in NR (P < 0.001; odds ratio [OR] = 1.95), as was the frequency of the KIR2DL2/KIR2DL2 genotype (P < 0.005; OR = 2.52). In contrast, the frequencies of the KIR2DL3 genotype (P < 0.001) and KIR2DL3/KIR2DL3 genotype (P < 0.05; OR = 0.54) were significantly increased in the SVR. Different combinations of KIR2DL2 and KIR2DL3 alleles with their ligands were analyzed. The frequency of the KIR2DL2/KIR2DL2-HLA-C1C2 genotype was significantly increased in the NR (P < 0.01; OR = 3.15). Additionally, we found a higher frequency of the KIR2DL3/KIR2DL3-HLA-C1C1 genotype in the SVR group (P < 0.05; OR = 0.33). These results were not affected by the HCV genotype. In conclusion, patients who carried the KIR2DL2/KIR2DL2-HLA-C1C2 genotype were less prone to respond to treatment. However, the KIR2DL3/KIR2DL3-HLA-C1C1 genotype clearly correlated with a satisfactory response to treatment, defined by the clearance of HCV RNA.

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Prevalence of Genotype 3a in Different Regions of Pakistan: A systematic Review and Meta-Analysis

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i44a32628 ◽

2021 ◽

pp. 376-382

Author(s):

Rehan Ahmad Khan Sherwani ◽

Maria Aslam ◽

Kanwal Saleem ◽

Atif Khan Jadoon ◽

Hafiz Muhammad Nawaz

Keyword(s):

Systematic Review ◽

Hepatitis C Virus ◽

Hepatitis C ◽

Literature Review ◽

Confidence Interval ◽

Meta Analysis ◽

Hcv Genotype ◽

Genotype 3A

The present study aims to explore the prevalence of genotype 3a under hepatitis C virus (HCV) infections among all the provinces of Pakistan. It is alarming to note that Pakistan stands in the second position for having a large number of cases of HCV every year. Six major genotypes characterize HCV. To study the overall prevalence of HCV and its associated genotype 3a in all the provinces of Pakistan, a systematic review and meta-analysis were performed using STATA version 14.2. The published studies conducted in all the regions of Pakistan reported the incidence of HCV genotype 3a were shortlisted. The pooled summary estimates were calculated along with their confidence interval by using the "Metaprop" command. The literature review showed that the prevalence of HCV genotype 3a is most common in all the provinces of Pakistan. It is revealed that the prevalence of HCV genotype 3a was 86.46% in Punjab, which is the highest among all the regions.

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