Analysis of interferon signaling by infectious hepatitis C virus clones with substitutions of core amino acids 70 and 91.

在此，我们用丙型肝炎病毒核心突变株R70Q、R70H和L91M与丙型肝炎病毒细胞培养，研究了干扰素应答的不同机制。干扰素信号衰减剂SOCS3在R70Q、R70H和L91M突变株的表达水平显著高于野生型。在R70Q、R70H和L91M突变体中，上调SOCS3的白介素6(IL-6)显著高于野生型，这表明干扰素抵抗可能是通过IL-6诱导的、SOCS3介导的干扰素信号抑制而实现的。内质网应激蛋白在核心突变体细胞中的表达水平显著高于野生型细胞。本实验室构建的丙型肝炎病毒2b/JFH1嵌合病毒可感染HuH7。5.1细胞，对干扰素的敏感性明显高于JFH1。通过siRNA敲除SOCS3的表达，并用抗IL6抗体预处理，JFH1细胞对干扰素的耐药性被逆转。这些结果提示，丙型肝炎病毒干扰素敏感性的差异可能与丙型肝炎病毒结构蛋白序列有关，并可由SOCS3和IL-6的表达水平决定，这种差异可能是由内质网激素引起的。

Here we investigated mechanisms of difference in the response to alpha interferon(IFN) by using HCV cell culture with HCV core mutant R70Q, R70H, and L91M virus clones The expression level of an interferon signal attenuator, SOCS3, was significantly higher for the R70Q, R70H, and L91M mutants than for the wild type. Interleukin 6(IL-6), which upregulates SOCS3, was significantly higher for the R70Q, R70H, and L91M mutants than for the wild type, suggesting interferon resistance, possibly through IL-6-induced, SOCS3-mediated suppression of interferon signaling. Expression levels of endoplasmic reticulum(ER) stress proteins were significantly higher in cells transfected with a core mutant than in those transfected with the wild type. The HCV-2b/JFH1chimeric virus, which was constructed in our laboratory, able to infect Huh7. 5. 1 cells and was significantly more sensitive to IFN than JFH1. The IFN resistance of JFH1 cells was negated by siRNA-knock down of SOCS3 expression and by pretreatment with anti-IL6 antibody. These data suggest that these differences of IFN sensitivity of HCV may be attributable to the sequences of HCV structural proteins and can be determined by SOCS3 and IL-6 expression levels, which might be induced by ER etress.