Expression of hepatitis C virus NS5A natural mutants in a hepatocytic cell line inhibits the antiviral effect of interferon in a PKR-independent manner
2001; Lippincott Williams & Wilkins; Volume: 33; Issue: 6 Linguagem: Inglês
10.1053/jhep.2001.24749
ISSN1527-3350
AutoresPhilippe Podevin, Abdelmajid Sabile, Rodrigo Gajardo, Nadira Delhem, Annie Abadie, Pierre‐Yves Lozach, Laura Beretta, Christian Bréchot,
Tópico(s)interferon and immune responses
ResumoThe impact of hepatitis C virus NS5A protein mutations on interferon alfa (IFN-alpha) signaling pathway, cell proliferation, and viability is an important issue that is still under debate. We have therefore combined transient and stable expression in a human hepatocytic cell line (Huh7) of 3 full-length NS5A sequences, isolated from patients with or without response to IFN-alpha therapy. Expression of all 3 NS5A-reduced IFN-alpha global antiviral activity on both vesicular stomatitis virus (VSV) and encephalomyocarditis virus (EMCV) replication. We did not show, however, an effect of these 3 NS5A proteins on double-stranded RNA-dependent kinase (PKR) expression and activity as well as colocalization and coimmunoprecipitation between NS5A and PKR. We also failed to show an effect of the 3 NS5A mutants tested on cell proliferation and viability. Overall, our results support an important role of NS5A in controlling IFN-alpha antiviral activity; they show, however, that PKR-independent mechanisms are implicated, at least in liver-derived cells.
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