脑心肌炎病毒VP1蛋白抑制Ⅰ型IFN信号通路和促进病毒体外增殖

脑心肌炎病毒是一种重要的人畜共患病病原,为了初步研究EMCV介导的天然免疫反应的分子机制,将VP1蛋白克隆至真核表达载体pCMV-HA,转染HEK293细胞后,使其在细胞内过表达,通过ELISA和实时荧光定量PCR检测VP1过表达对IFN-β表达和RLRs信号通路相关因子,以及下游刺激基因表达的影响。结果表明,VP1蛋白可显著抑制IFN-β的表达。进一步研究发现,VP1可显著抑制EMCV引起的RLRs信号通路相关因子mRNA水平(P<0.01),并且随着VP1的表达,MAVS蛋白的表达明显减少,但对MDA5表达无影响。实验数据初步表明,VP1蛋白可以通过抑制MAVS的表达,进而抑制Ⅰ型IFN基因的表达并阻断其下游信号通路发挥作用。

VP1 protein of encephalomyocarditis virus inhibits type I IFN signaling pathway and promotes virus proliferation in vitro

Encephalomyocarditis virus (EMCV) is an important zoonotic pathogen. In order to preliminarily study the molecular mechanism of EMCV mediated innate immune response, this study cloned VP1 protein into eukaryotic expression vector pCMV-HA, transfected it into HEK293 cells to make it overexpress in cells. The effects of VP1 overexpression on IFN-β expression and RLRs signaling pathway-related factors and downstream stimulation gene expression were detected by ELISA and real time fluorescence quantitative PCR. Results showed VP1 could significantly inhibit IFN-β expression. Further study found that VP1 could significantly inhibit the mRNA level of EMCV-induced RLRs signaling pathway-related factors, and with the expression of VP1, MAVS protein expression was significantly reduced, but had no effect on the expression of MDA5. Therefore, the data of this experiment preliminarily showed that VP1 protein could inhibit the expression of type Ⅰ IFN gene expression and block its downstream signaling pathway by inhibiting the expression of MAVS.