猪流行性腹泻病毒变异株抑制宿主补体C3蛋白的分子机制

猪流行性腹泻病毒（PEDV）的暴发流行给世界养猪业造成重大经济损失。宿主补体C3蛋白在整个补体系统激活及抗病毒感染中起着核心作用，但目前关于C3蛋白与PEDV感染的相互作用关系及分子机制尚无报道。前期研究发现，与PEDV经典毒株相比，变异株具有通过抑制C3蛋白表达而逃避其抗病毒的能力。本研究拟利用基因突变和反向遗传技术，构建不同PEDV毒株非结构和结构蛋白表达载体和重组病毒，进一步明确PEDV变异株抑制C3蛋白表达的关键蛋白及其关键位点；通过病毒感染和关键蛋白表达载体转染细胞，检测C3蛋白不同激活途经中重要蛋白的表达及活化水平，炎性细胞因子水平，以及病毒关键蛋白与C3蛋白本身及其激活途径蛋白的相互作用关系，阐明PEDV变异株抑制C3蛋白的信号通路分子机制，丰富其致病机制和逃避先天免疫的理论基础。

The outbreaks of porcine epidemic diarrhea virus (PEDV) have caused major economic losses to pig industries in the world. Host complement C3 protein plays a central role in the whole complement system activation and antiviral infection, but there is no report about the interactions and molecular mechanisms of C3 protein and PEDV infection. Previous studies have found that PEDV variant strains have the ability to evade the antiviral response by inhibiting the expression of C3 protein compared to the classical strains. In this study, the non-structural and structural protein expression vectors of different PEDV strains and recombinant strains will be constructed by using gene mutation and reverse genetics techniques to further clarify the functional proteins and key sites of PEDV variants, which inhibit C3 protein expression. Through the viral infection and functional protein expression vectors transfection, the expression and activation of important proteins in different activation pathways of C3 protein, the levels of inflammatory cytokines and the interaction between viral functional proteins with C3 and its activation pathway proteins will be detected to elucidate the signaling pathway of PEDV inhibiting the C3 protein expression. This research plans to enrich the theoretical basis of PEDV variants escaping innate immunity and its pathogenesis.