Related Experiment Video

Updated: Sep 20, 2026

Two Methods of Heterokaryon Formation to Discover HCV Restriction Factors
16:49

Two Methods of Heterokaryon Formation to Discover HCV Restriction Factors

Published on: July 16, 2012

Selection of HCV NS5A quasispecies during IFN therapy in patients with chronic HCV

M Paterson1, C Laxton, R D Goldin

  • 1Liver Centre, Imperial College School of Medicine at St Mary's, St Mary's Hospital. London, UK.

Digestive Diseases and Sciences
|August 2, 2001
PubMed

Insights

Interferon treatment for chronic hepatitis C virus (HCV) infection shows limited success. While interferon (IFN) therapy selects for ISDR quasispecies, the specific HCV-J sequence linked to resistance was not enriched, suggesting other factors influence treatment outcomes.

Area of Science:

  • Hepatology
  • Virology
  • Immunology

Background:

  • Hepatitis C virus (HCV) infection is a significant global health concern.
  • Interferon (IFN) therapy is a treatment for chronic HCV infection, but its success rate is low.
  • The interferon sensitivity determining region (ISDR) within the NS5A protein of HCV genotype 1 is hypothesized to influence treatment outcomes.

Purpose of the Study:

  • To investigate whether IFN treatment selects for specific ISDR quasispecies in patients with HCV.
  • To determine if the putative IFN-resistance motif (HCV-J sequence) is enriched following IFN therapy.
  • To analyze amino acid changes in the ISDR across different HCV genotypes with and without IFN treatment.

Main Methods:

  • Analysis of amino acid sequences within the ISDR of the NS5A protein.
  • Comparison of ISDR sequences in patients with and without interferon therapy.
  • Examination of sequence variability and selection pressures across different HCV genotypes.

Main Results:

  • The ISDR sequence exhibits high variability, particularly in patients with HCV genotype 1.
  • IFN treatment exerts a selection pressure on ISDR quasispecies.
  • The putative IFN-resistant HCV-J variant was not found to be enriched in patients of any genotype studied.

Conclusions:

  • The sequence variability within the ISDR of HCV is significant.
  • IFN treatment influences the quasispecies composition of the ISDR.
  • Factors beyond the ISDR sequence are likely responsible for interferon resistance in HCV patients.

More Related Videos

A Protocol for Analyzing Hepatitis C Virus Replication13:04

A Protocol for Analyzing Hepatitis C Virus Replication

Published on: June 26, 2014

Reverse Genetics to Engineer Positive-Sense RNA Virus Variants15:49

Reverse Genetics to Engineer Positive-Sense RNA Virus Variants

Published on: June 9, 2022

Related Concept Videos

Hepatitis01:25

Hepatitis

Hepatitis is an inflammatory condition of the liver most commonly caused by hepatotropic viruses (A–E), though non-infectious causes such as alcohol and drugs also exist.Hepatitis AHepatitis A virus (HAV) is a non-enveloped RNA virus of the Picornaviridae family. It is primarily transmitted via the fecal-oral route, typically through ingestion of contaminated food or water. After ingestion, HAV enters the bloodstream through the oropharynx or intestinal epithelium and reaches the liver. The...
Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
Antiviral Nucleoside Inhibitors01:22

Antiviral Nucleoside Inhibitors

Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),...
Viral Hepatitis I: Introduction01:28

Viral Hepatitis I: Introduction

Viral hepatitis is an inflammatory condition of the liver caused by infection with hepatotropic viruses, most commonly hepatitis A, B, C, D, and E. Despite variations in structure and transmission, all viruses mentioned infect hepatocytes and provoke immune responses that can hinder liver function. Additionally, some non-hepatotropic viruses can also lead to hepatic inflammation.Hepatitis A VirusHepatitis A virus (HAV) is transmitted through the fecal–oral route, typically by ingestion of food...