[Show abstract][Hide abstract] ABSTRACT: Hepatitis C virus (HCV) is a positive sense, single-stranded RNA virus in the Flaviviridae family. It causes acute hepatitis with a high propensity for chronic infection. Chronic HCV infection can progress to severe liver disease including cirrhosis and hepatocellular carcinoma. In the last decade, our basic understanding of HCV virology and life cycle has advanced greatly with the development of HCV cell culture and replication systems. Our ability to treat HCV infection has also been improved with the combined use of interferon, ribavirin and small molecule inhibitors of the virally encoded NS3/4A protease, although better therapeutic options are needed with greater antiviral efficacy and less toxicity. In this article, we review various aspects of HCV life cycle including viral attachment, entry, fusion, viral RNA translation, posttranslational processing, HCV replication, viral assembly and release. Each of these steps provides potential targets for novel antiviral therapeutics to cure HCV infection and prevent the adverse consequences of progressive liver disease.
Clinical and molecular hepatology. 03/2013; 19(1):17-25.
[Show abstract][Hide abstract] ABSTRACT: As a persistent virus, hepatitis B virus (HBV) is believed to be noncytopathic in most circumstances, with its disease pathogenesis
mediated by host innate and adaptive immune responses. Although HBV may initially avoid activating critical innate intracellular
defenses (eg, type I interferons), T cells exert both cytopathic and noncytopathic antiviral effects toward resolution of
HBV infection. With chronic HBV infection, various immune regulatory or tolerance mechanisms are induced with varying degrees
of effector T-cell dysfunction and liver inflammation, which contributes to liver disease progression. This review highlights
some components of host immune response relevant for HBV infection, including the more recent appreciation of immune regulatory
mechanisms induced during chronic viral infection. Although therapeutic options are evolving for HBV, a better understanding
of its immune pathogenetic and regulatory mechanisms may help develop better approaches to treat HBV infection and prevent
KeywordsHepatitis B virus-Immunity-Viral pathogenesis-Immune regulation-Tregs-IL-10-PD-1