长链非编码IFNG-AS1调控MHCII分子可变剪切和泛素化参与CD4+T细胞活化在重症肌无力中的研究

研究证实MHCII分子的基因多态性与重症肌无力发病密切相关，CD4+T细胞识别MHCII分子递呈的多肽抗原，活化后分泌细胞因子，辅助B细胞产生抗体在重症肌无力(MG)发病中扮演重要角色。我们前期研究发现长链非编码IFNG-AS1对MHCII分子HLA-DRB等表达具有调节作用，且IFNG-AS1可通过hnRNPU/K影响MHCII分子的甲基化。但IFNG-AS1调控何种MHCII分型的表达以及是否还有其他调控MHCII分子活化CD4+T细胞的机制仍需进一步探索。基于前期研究基础，本项目拟运用高通量测序分析IFNG-AS1与MHCII分子基因分型的关系；同时拟采用RIP、质谱等技术研究IFNG-AS1通过RNA剪切蛋白及泛素连接酶参与MHCII分子的可变剪切和泛素化过程，从而影响CD4+T细胞的激活和分化，为IFNG-AS1在MG中的机制研究及临床治疗提供理论基础和实验依据。

Previous studies confirmed that the MHC II genetic polymorphism was closely related to the onset of MG. This molecule could present peptide antigens, which plays an important role in Myasthenia Gravis (MG) pathogenesis since it could participate in the activation of CD4+T cells. After CD4+T cells have been activated, those cells could secrete different cytokines to stimulate B cells to produce antibodies. Our previous studies have shown that long non-coding IFNG-AS1 not only could downregulate the activation of CD4+T cells and decrease the expression of MHC II molecules (HLA-DRB etc.) in MG patients, but also could affect the methylation of MHC II molecules through hnRNPU/K. However, which gene type of MHC II is the specific target of IFNG-AS1 remains unknown, even mechanisms of how IFNG-AS1 could regulate MHC II molecules and inhibit CD4+T cell activation still need to be further explored. Based on our preliminary data originated from RNA pull down and mass technology experiments, we intends to use high-throughput sequencing to explore the relationship between IFNG-AS1 and genotyping of MHC II molecules; and it is planned to perform a series of experiments including RIP coprecipitation, mass spectrometry, sequencing to examine the regulatory function of IFNG-AS1 involves in MHC II molecular alternative splicing by binding the RNA splicing protein. In addition, the other aim is to identify IFNG-AS1 regulates MHC II molecular ubiquitination by binding ubiquitin ligase, which would influence the activation and differentiation of CD4+ T cell. Therefore, the purpose of this study is to provide theoretical and experimental basis for the development and clinical treatment of IFNG-AS1 in MG.