干扰素γ对丙型肝炎病毒复制子的抑制作用

The direct antiviral effect of interferon-γ on hepatitis C virus repiicon

目的研究干扰素(IFN)γ直接抑制丙型肝炎病毒(HCV)复制子的作用及其与IFN α联合用药的疗效,并对可能介导IFN γ抗HCV作用的干扰素刺激基因(ISG)的表达水平进行探讨。方法建立HCV复制子细胞模型,用IFN γ或IFN γ联合IFN α处理HCV复制子细胞,通过半定量逆转录聚合酶链反应(RT-PCR)及实时定量PCR检测细胞中HCV RNA水平;western blot检测细胞中HCV非结构蛋白5A(NS5A)。结果 IFN γ对HCV RNA的复制及NS5A的表达有明显抑制作用,10 U／ml IFN γ可使 HCV RNA较对照组减少36％,25 U／ml减少80％;IFN γ对HCV RNA及NS5A蛋白的抑制作用与其剂量及作用时间呈正相关。用IFN γ预处理的细胞对IFN α抗HCV的作用更敏感,且细胞内干扰素调节因子 -l(IRF-1)、干扰素刺激基因因子3 γ(ISGF3 γ)和2’5’-寡腺苷酸合成酶(2’5’-OAS)呈明显的诱导性表达。结论 IFN γ能有效抑制HCV RNA的复制,并与IFN α有协同抗HCV的作用。IRF-1、ISGF3 γ和2’5’-OAS可能参与介导IFN γ抗HCV的作用。

Objectives To study the effects of interferon-γ and interferon-γ combined with interferon-α on HCV RNA replication and the possible mediators of interferon-γ anti-HCV in vitro. Methods An HCV replicon cell culture system was established and the cells were treated with interferon-γ or interferon-γ combined with interferon-α. HCV RNA levels in the cells were evaluated by semi-quantitative RT-PCR and real-time PCR, and the levels of NS5A protein were examined by Western blot. Results Interferon-γ could inhibit HCV RNA replication and NS5A protein expression effectively; The anti-HCV effects of interferon-γ were both in time-dependent and does-dependent manners; Pretreating the cells with interferon-γ could significantly enhance the antiviral effects of interferon-α; The expressions of IRF-1, 2＇5＇-OAS1（p46）, 2＇5＇-OAS2（p69）, ISGFγ/and STAT1 were significantly increased after interferon-γ treatment. Conclusion Interferon-γ has a direct inhibitory effect on HCV replicon RNA replication and NS5A expression, and both are in a dose and time dependent manner; Interferon-γ has a synergistic anti-HCV effect with interferon-α. IRF-1,2＇5＇-OAS1（p46）, 2＇5＇-OAS2（p69） and ISGF3γ may mediate the anti-HCV effects of interferon-γ.