磷酸酶PP2CB抑制RNA病毒VSV或SeV介导的天然免疫应答  

Phosphatase PP2CB inhibits innate immune response triggered by RNA virus VSV or SeV

作　　者：周庆卿 张赟恺 陈祥[1] 刘星光[1] ZHOU Qing-Qing ZHANG Yun-Kai CHEN Xiang LIU Xing-Guang(National Key Laboratory of Medical Immunology ＆ Institute of Immunology, Second Military Medical University, Shanghai 200433, Chin)

机构地区：[1]第二军医大学免疫学研究所暨医学免疫学国家重点实验室,上海200433

出　　处：《中国免疫学杂志》2017年第6期818-822,827,共6页Chinese Journal of Immunology

基　　金：国家自然科学基金优秀青年科学基金(81422021)资助

摘　　要：目的:研究蛋白磷酸酶PP2CB在抗RNA病毒天然免疫应答中的调控作用及其机制。方法:在小鼠腹腔巨噬细胞中转染PP2CB的特异siRNA,干扰其表达后通过Q-PCR和ELISA观察RNA病毒诱导的Ⅰ型干扰素的产生变化、病毒在细胞内的复制变化,Western blot检测TBK1和IRF3的磷酸化水平的改变。结果:VSV感染诱导巨噬细胞中PP2CB的表达发生显著改变。过表达PP2CB抑制HEK293细胞中IFN-β的转录活化。干扰PP2CB表达显著升高RNA病毒VSV或SeV诱导的Ⅰ型干扰素的mRNA和蛋白表达水平,并抑制VSV复制。此外,RNA病毒诱导PP2CB和TBK1结合。干扰PP2CB的表达能够增强TBK1和IRF3的磷酸化。结论:RNA病毒VSV或SeV使蛋白磷酸酶PP2CB能够结合TBK1并抑制其磷酸化,下调Ⅰ型干扰素信号通路的活化,从而负向调控RNA病毒VSV或SeV诱导的Ⅰ型干扰素的产生。Objective： To investigate the role of phosphatase PP2CB in the innate immunity against RNA virus and the underlying mechanism. Methods： PP2CB expression in macrophages was silenced with the specific siRNA. The mRNA and protein expression level of type I interferon was detected by Q-PCR and ELISA respectively. The phosphorylation level of TBK1 and IRF3 was analyzed by Western blot. Results ： RNA virus VSV infection led to the expression change of PP2CB. Overexpression of PP2CB dose-de- pendently inhibited the activation of IFN-13 reporter gene. PP2CB silencing by PP2CB siRNA significantly promoted the production of type I interferon triggered by RNA virus VSV or SeV, and inhibited the replication of VSV in macrophages. Furthermore, PP2CB bound TBK1 upon RNA virus infection. PP2CB silencing up-regulated the phosphorylation level of TBK1 and IRF3. Conclusion ： Upon RNA virus VSV or SeV infection,phosphatase PP2CB binds TBK1 and inhibits its phosphorylation to negatively regulate the activation of the antiviral innate immune signal pathway ,which consequently suppresses the production of type I interferon triggered by RNA virus VSV or SeV.

关 键 词：蛋白磷酸酶PP2CB 天然免疫 Ⅰ型干扰素 巨噬细胞 

分 类 号：R392.12[医药卫生—免疫学]