HCV核心蛋白抑制干扰素α诱导的抗病毒基因表达及其机制研究

Study of the Effect of Hepatitis C Virus Core Protein on Interferon-induced Antiviral Genes Expression and Its Mechanisms

摘要:

研究HCV核心蛋白对干扰素α诱导的抗病毒分子PKR和2′-5′OAS表达的影响及其机制。HCV核心蛋白表达质粒转染HepG2细胞，RT-PCR分析PKR和2′-5′OAS的mRNA水平变化，荧光素酶活性分析核心蛋白对ISRE介导的基因表达的影响；Western-blot分析SOCS3、STAT1及STAT1磷酸化水平的变化。在干扰素α刺激情况下，表达HCV核心蛋白的细胞中，PKR和2′-5′OAS的mRNA水平下降，ISRE介导的荧光素酶活性降低，STAT1磷酸化水平下降。此外，核心蛋白表达的细胞中SOCS3的mRNA和蛋白水平明显升高。结果表明，HCV核心蛋白可能通过激活SOCS3、抑制STAT1的磷酸化，从而下调干扰素α诱导的PKR和2′-5′OAS表达。

关键词:丙型肝炎病毒， 核心蛋白， 干扰素α， STAT1， SOCS3

Abstract:

To study the effect of HCV core protein on the interferon-induced antiviral genes expression and its mechanisms. Methods HepG2 cells were transiently transfected with HCV core protein expression plasmid and the blank plasmid respectively. RT-PCR was used to analyze the effect of HCV core protein on PKR and 2′-5′OAS expression. The effect of HCV core protein on ISRE-medicated gene expression was detected by luciferase activity assay. Western-blot assay was performed to observe the change of mRNA and protein levels of SOCS3，STAT1 and p-STAT1 following HCV core expression. In the presence of HCV core protein，the transcription of PKR and 2′-5′OAS are down-regulated. ISRE-medicated reporter gene expression and STAT1 phosphorylation were inhibited. The transcription and expression of SOCS3 were induced compared with blank plasmid-transfected group. In HepG2 cells，HCV core protein can down-regulate the expression of some interferon-induced antiviral genes，which involves the induction of SOCS3 and the inhibition of STAT1 phosphorylation.

Key words:hepatitis C virus， core protein， interferon-α， STAT1， SOCS3