兔出血症病毒非结构蛋白NSP6抑制IFN-β产生的分子机制

兔出血症病毒（RHDV）的非结构蛋白NSP6属于3C样蛋白酶，该类蛋白酶与病毒的复制和致病性密切相关。我们前期发现，RHDV感染后肝脏组织内干扰素诱导蛋白显著下调，且NSP6可极显著抑制干扰素β（IFN-β）启动子活性，提示NSP6在抑制IFN-β产生中发挥重要作用，然而具体机制未知。本项目拟通过真核表达NSP6蛋白，检测NF-κB/p65和IRF3的激活情况，明确NSP6对NF-κB和IRF3信号通路的影响；在此基础上，过表达I型干扰素产生途径中IPS-1和NEMO等重要信号分子，检测NSP6对信号分子诱导IFN-β产生的影响，明确与NSP6抑制IFN-β产生相关的关键信号分子。最后通过构建突变体NSP6，分析NSP6抑制IFN-β产生与其蛋白酶活性的依赖关系。本项目的开展将系统阐明NSP6蛋白抑制IFN-β产生的分子机制，丰富RHDV的致病机理。

Non-structural proteins 6(NSP6) of rabbit hemorrhagic disease virus (RHDV) belongs to 3C-like protease. This kind of protease is closely related to virus replication and pathogenicity. Our previous studies showed antiviral molecules of innate immunity in liver decreased significantly after RHDV infection and NSP6 had strongest inhibitory effects on IFN-β promoter activation. That suggested NSP6 can inhibit the IFN-β production, but the underlying mechanisms remain unclear. In this research, we first study the NF-κB and IRF3 signal pathways influenced by NSP6, using the luciferase reporter. Then, after overexpression of IPS-1 and NEMO, we will research the effects on inhibition of IFN-β production mediated by NSP6, and confirm the key signal molecules. At last, we will study the relationship between the catalytic activity and the ability of inhibiting IFN-β production of NSP6 by using NSP6 mutants. Collectively, the study can clarify the mechanism of non-structural proteins 6 of RHDV inhibiting IFN-β production, and enrich the mechanisms of pathogenesis in RHDV.