Expression of hepatitis C virus proteins inhibits signal transduction through the Jak-STAT pathway.
J Virol
; 73(10): 8469-75, 1999 Oct.
Article
in En
| MEDLINE
| ID: mdl-10482599
ABSTRACT
Hepatitis C virus (HCV) infection is a leading cause of liver disease worldwide. Alpha interferon (IFN-alpha) therapy of chronic hepatitis C leads to a sustained response in 10 to 20% of patients only. The mechanisms of viral persistence and the pathogenesis of hepatitis C are poorly understood. We established continuous human cell lines, allowing the tightly regulated expression of the entire HCV open reading frame under the control of a tetracycline-responsive promoter. Using this in vitro system, we analyzed the effect of HCV proteins on IFN-induced intracellular signaling. Expression of HCV proteins in these cells strongly inhibited IFN-alpha-induced signal transduction through the Jak-STAT pathway. Inhibition occurred downstream of STAT tyrosine phosphorylation. Inhibition of the Jak-STAT pathway was not restricted to IFN-alpha-induced signaling but was observed in leukemia inhibitory factor-induced signaling through Stat3 as well. By contrast, tumor necrosis factor alpha-induced activation of the transcription factor NF-kappaB was not affected. Interference of HCV with IFN-alpha-induced signaling through the Jak-STAT pathway could contribute to the resistance to IFN-alpha therapy observed in the majority of patients and may represent a general escape strategy of HCV contributing to viral persistence and pathogenesis of chronic liver disease.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Viral Proteins
/
Signal Transduction
/
Hepatitis C
/
Hepacivirus
Limits:
Humans
Language:
En
Journal:
J Virol
Year:
1999
Document type:
Article
Affiliation country:
Switzerland