HCV

Hepatitis C is an infectious disease that leads to inflammation of the liver caused by the hepatitis C virus (HCV). The infection is often asymptomatic, but once established, chronic infection can progress to scarring of the liver (fibrosis), and advanced scarring (cirrhosis) which is generally apparent after many years. In some cases, those with cirrhosis will go on to develop liver failure or other complications of cirrhosis, including liver cancer or life threatening esophageal varices and gastric varices.

The hepatitis C virus is spread by blood-to-blood contact. Most people have few, if any symptoms after the initial infection, yet the virus persists in the liver in about 85% of those infected. Persistent infection can be treated with medication, peginterferons and ribavirin being the standard-of-care therapy. Currently about half off all patients are being cured with the standard of care medications. Those who develop cirrhosis or liver cancer may require liver transplantation, and the virus universally recurs after that procedure.

An estimated 270-300 million people worldwide are infected with hepatitis C

We offer the following assays for the HCV drug discovery and development programs:

  •  In vitro infection assays
  • In vitro enzymatic assays
  • HCV replicons

Combination Studies. In this analysis, synergistic or antagonistic effects of drugs are distinguished from additive effects. Compounds are evaluated in combination with ribavirin, IFN alpha and other drugs to examine if there are greater than additive, synergistic or antagonistic effects on both antiviral activity and cytotoxicity.

Comprehensive Drug Toxicity Evaluation We can test compounds for toxicity against a large panel of established cell lines, human PBMCs and human primary hepatocyte cultures.

HCV Molecular Target Assays Here we test compounds for their abilities to inhibit HCV-specific molecular targets.

  • NS5B assay
    An in vitro assay of the HCV RNA-dependent RNA polymerase NS5B can be used to determine if drugs specifically inhibit this activity.
  • NS3 protease assay
    An in vitro assay of HCV NS3 protease substrate cleavage inhibition.
  •  IRES assay
    A dual luciferase assay can assay the ability of compounds to inhibit HCV IRES-mediated translation.

Mechanism of Action Studies
A variety of mechanistic studies are possible with most of the surrogate viruses including:

  • Time of drug addition studies
    Indicate the point in the viral replication cycle during which the drug acts.
  • RNA accumulation studies
    To show inhibition viral RNA synthesis by drugs.
  • Variable MOI effects
    We investigate the effect of varying viral multipicity of Infection on the antiviral activity of test compounds.
  •  Drug effects on virion infectivity
    If test compounds are mutagenic then the infectivity of the viruses produced under these conditions is reduced dramatically.

    • Assembly: intracellular particle infectivity
    • Secretion: extracellular particle infectivity
    • Effects on spread of viral infection in tissue culture (immunohistochemistry and immunofluorescence microscopy). These studies determine if test compounds block re-infection of cells in tissue culture (for example, if viral entry is targeted).
    • Virus stability: viricidal activity
    • Drug resistance studies
      • Selection of resistant virus or replicons
      • Mutation ID
      • Confirming resistance via reverse genetics