USP43促进RNF2介导的TBK1泛素化降解负向调控抗病毒天然免疫的作用及机制研究

去泛素化酶在多种生理过程中发挥重要作用，但其成员泛素特异性蛋白酶43（USP43）在抗病毒天然免疫应答中的功能尚不清楚。我们前期利用去泛素化酶质粒库，筛选到抗病毒天然免疫应答的负调分子USP43，且证实病毒感染下调USP43的表达。此外，小鼠巨噬细胞干扰或敲除USP43促进VSV、H1N1和HSV诱导的I型干扰素表达，且增强细胞抗病毒能力；USP43敲除小鼠VSV诱导的病毒感染模型证实USP43缺陷在体内增强机体抗病毒能力。多组学质谱分析和机制研究发现USP43能够稳定泛素连接酶RNF2从而促进TBK1泛素化降解，进而负向调控抗病毒天然免疫应答。本项目拟利用USP43及RNF2敲除小鼠，进一步通过体内外实验研究USP43/RNF2/TBK1轴在调控细胞及机体抗病毒天然免疫应答中的作用及机制，阐明泛素连接酶RNF2自身泛素化修饰的调控过程，为病毒感染性疾病的防治提供新的见解和潜在治疗靶点。

Deubiquitinases play an important role in a variety of physiological processes, but the function of its member ubiquitin-specific protease 43 in antiviral innate immune response is unclear. In our previous study, we used the deubiquitination enzyme plasmids library to screen and found antiviral innate immune response regulator USP43, and the results also revealed that viral infection down-regulated the expression of USP43. USP43 knockdown or knockout in macrophage promoted VSV, H1N1 and HSV-induced type I interferon expression, and enhanced the antiviral response. USP43 knockout mice infected by VSV confirmed that USP43 defect could promote the antiviral response in vivo. Multi-proteomics mass spectrometry and the mechanism studies have shown that USP43 promotes RNF2 mediated TBK1 ubiquitination and degradation, and then negatively regulates the antiviral innate immune response. This project plans to elucidate the role and mechanism of USP43/RNF2/TBK1 axis in antiviral innate immune response and uncover the ubiquitin ligase RNF2 ubiquitination modification by using USP43 and RNF2 knockout mice in vitro and in vivo, expecting to providing new insights and potential therapeutic targets for prevention and treatment of viral infection diseases.