Cytopathic and noncytopathic interferon responses in cells expressing hepatitis C virus subgenomic replicons.
Hepatitis C virus (HCV) is the only known positive-stranded RNA virus that causes persistent lifelong infections in humans. Accumulation of HCV RNA can be inhibited with alpha interferon (IFN-alpha) in vivo and in culture cells. We used cell-based assay systems to investigate the mechanisms responsible for the cytokine-induced inhibition of HCV replication. The results showed that IFN-alpha could suppress the accumulation of viral RNA by a noncytopathic pathway and could also induce apoptosis of virally infected cells in a concentration- and cell line-dependent fashion. Whereas the noncytopathic IFN-alpha response depended on a functional Jak-STAT signal transduction pathway, it did not appear to require double-stranded RNA-dependent pathways. Moreover, we found that functional proteasomes were required for establishment of the IFN-alpha response against HCV. Based on the results described in this study we propose a model for the mechanism by which IFN-alpha therapy suppresses HCV replication in chronic infections by both cytopathic and noncytopathic means.
D000998:Antiviral Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000502:physiology; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology*; D016899:Interferon-beta / Q000096:biosynthesis; D012367:RNA, Viral / Q000032:analysis / Q000502:physiology; D011991:Receptors, Virus / Q000187:drug effects; D012093:Replicon; D050795:STAT2 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000502:physiology
D000998:Antiviral Agents; D004268:DNA-Binding Proteins; D016898:Interferon-alpha; D012367:RNA, Viral; D011991:Receptors, Virus; D050795:STAT2 Transcription Factor; D015534:Trans-Activators; D016899:Interferon-beta