RNA病毒感染早期人肝脏细胞固有免疫反应

Innate immune response of human hepatocytes in early phase of RNA virus infection

目的:检测RNA病毒感染早期人肝脏细胞中免疫相关基因的诱导情况,揭示肝细胞特有的固有免疫反应。方法:以原代培养人肝细胞作为研究对象,利用仙台病毒(SV)感染,根据感染时间不同分为0、3及6h组,利用间接免疫荧光法检测干扰素调节因子3(IRF3)和干扰素调节因子7(IRF7)的细胞内分布情况;将SV感染的原代肝细胞按照感染时间不同分为0、1、2及3h组,利用Real-time PCR检测感染早期细胞中IFNα1、IFNβ、IFNλ3及维甲酸诱导I型基因(RIG-I)的表达。结果:原代肝细胞中,SV感染0h,IRF3和IRF7均分布于细胞质中;感染3h,部分细胞的IRF7分布于细胞核中,IRF3仍分布于细胞质中;SV感染6h,部分细胞的细胞核中发现IRF7和IRF3的信号。Real-time PCR法检测,与感染0h组比较,SV感染2h组RIG-I、IFNβ及IFNλ3显著升高(P<0.05),IFNα1略有升高。结论:肝细胞内存在固有表达的IRF7,在感染早期发生细胞核内转移,与感染相关的干扰素基因被诱导表达,说明肝细胞针对病毒感染存在独特而快速的免疫反应。

Objective To check the induction of the expression of the genes related to the immune response of human hepatocytes at the early stage of RNA virus infection and to reveal the hepatocyte specific immune response.Methods The Sendai virus(SV) infected primary human hepatocytes were divided into 0,3 and 6 h groups,immunofluorescence(IF) assay was used to detect the location of IRF3 and IRF7.The SV infected primary human hepatocytes were divided into 0,1,2 and 3 h groups,the expressions of IFNα1,IFNβ and IFNλ3 and RIG-I in the hepatocytes at the early phase of infection were detected by Real-time PCR.Results The IRF3 and IRF7 were detected in the cytoplasma before SV infection.The signal of IRF7 was detected in the nuclear of some cells after 3 h infection of SV,and the signals of both IRF3 and IRF7 were detected in the nuclear of some cells after 6 h infection.Compared with 0 h SV infection group,the expressions of RIG-I,IFNβ and IFNλ3 were significantly increased and IFNα1 was slightly increased in 2 h SV infection group(P<0.05).Conclusion The nuclear translocation of the constitutively expressed IRF7 in hepatocytes occurs at the early stage of infection and is related to the induction of expression of the IFNs corresponding to the infection.It indicates that the hepatocytes have specific and fast immune response to the virus infection.