Inhibition on IFN-βExpression by hCV ns3 and ns5A in HepG2 Cells

摘要

Objective To observe the effects of HCV protein, NS3 and NS5A on IFN-βin HepG2 cells and its regulation mechanism. Methods Human liver hepatocellular carcinoma cells HepG2 were transfected with recombinant eukaryotic plasmid pcDNA3.1/myc-His-core, NS3 or NS5A to overexpress these proteins, and the expression of IFN-βwere detected by qRT-PCR, Western blotting and ELISA. Luc2P reporter plasmids pGL4.10-IFNβ-P were constructed and transfected into HepG2 cells, and the activity of IFN-βpromoter were determined through luciferase assay for regulation mechanism study. Results Both mRNA level and protein expression of IFN-β were significantly decreased (P < 0.05) in the presence of NS3 or NS5A protein. Luciferase assay revealed that NS3 or NS5A protein downregulated IFN-βpromoter activity (P< 0.05). Meanwhile, HCV core protein had little effect on IFN-βexpression. Conclusions HCV protein NS3 and NS5A could inhibit innate IFN-β expression and thus escape immune selection and hinder the host immune responses.