抗体依赖的细胞内中和效应作为机体最后一道防线，抵抗病毒感染。The tripartite motif protein 21 (TRIM21)作为胞浆内Fc受体，在其中起着关键作用。TRIM21可以识别胞浆内病毒-抗体复合物并将其靶定到蛋白酶体进行降解，致使病毒不能在细胞内发生复制。除泛素化修饰外，蛋白其他翻译后修饰如何调控TRIM21功能有待拓展和深入。前期研究发现，TRIM21作为乙酰化修饰蛋白出现在HDAC6底物多样性列表中。在该项目中，我们将深度分析HDAC6催化TRIM21发生去乙酰化修饰的分子作用机制，深度阐释TRIM21去乙酰化修饰对其功能的影响，进一步完善TRIM21介导的细胞内抗体依赖的中和效应的信号通路。预期研究结果的取得，将加深对TRIM21介导抗体依赖的细胞内中和效应作用机制的理解，提高对抗体依赖的细胞内中和效应作用机制认知，具有重要的理论和学术价值。

Antibody-dependent intracellular neutralization (ADIN) resist viral pathogen infection as the last line of defense. The tripartite motif protein 21 (TRIM21) has been identified as a cytosolic antibody receptor, which plays critical role in ADIN. TRIM21 acts as the intracellular antibody Fc receptor to target the internalized virus-antibody complexes to the proteasome for degradation before virus has time to replicate. The regulation of TRIM21 function by post-translational modifications (PTMs) needs to be further illustrated, except for ubiquitination. In our previous study of the substrate diversity of histone deacetylase 6 (HDAC6), we found that TRIM21 was included in the list of acetylated proteins. In this study, we will dissect deeply the molecular mechanism of how HDAC6 catalyze the deacetylation of TRIM21, also will explain the functional effects regulated by TRIM21 deacetylation, further will perfect ADIN signaling pathway mediated by TRIM21. If we finally achieve the end of our research, it is expected to know more about the mechanism of ADIN mediated by TRIM21, which has important theoretical and academic value.