SRSF9驱动的HLA-A可变剪接在类风湿关节炎滑膜成纤维细胞自身抗原提呈中的作用

自身抗原提呈是类风湿关节炎（RA）发病的中心事件，但发生机制未明。申请人发现，RA滑膜成纤维细胞抗原提呈分子HLA-A发生亢进的基因可变剪接，导致其抗原结合槽结构改变，且可变剪接因子SRSF9表达增加。故推测：SRSF9驱动HLA-A发生基因可变剪接而改变其抗原结合槽结构，促使HLA-A结合自身抗原，进而启动RA滑膜成纤维细胞自身抗原提呈。本课题拟采用CIA大鼠模型与RA患者原代滑膜成纤维细胞，探究HLA-A基因可变剪接对自身抗原提呈的影响；构建SRSF9基因沉默与过表达模型，揭示SRSF9对HLA-A基因可变剪接的调控作用；利用分子互作技术检测SRSF9与HLA-A pre-mRNA的结合作用及位点，阐明SRSF9调控HLA-A基因可变剪接的分子机制。本课题揭示RA自身抗原提呈发生的新机制，为开发阻断自身抗原提呈的新药提供潜在靶点，也为RA研究提供新思路。

Autoantigen presentation is the central event in the pathogenesis of rheumatoid arthritis (RA), but the mechanism is unknown. The applicant found that the hyperactive alternative splicing of antigen-presenting molecule HLA-A resulted in changes in the structure of its antigen binding groove, and increased expression of the alternative splicing factor SRSF9 in RA synovial fibroblast. Therefore, it is hypothesized that: SRSF9 drives HLA-A alternative splicing to change its antigen binding groove structure, prompting HLA-A to bind autoantigens, and then initiate RA synovial fibroblasts autoantigen presentation. The aim of this study is to explore the effect of HLA-A gene alternative splicing on autoantigen presentation by CIA rat model and primary synovial fibroblasts from RA patients; the regulatory effect of SRSF9 on HLA-A alternative splicing would revealed by constructing SRSF9 silencing and overexpression models; the interaction between SRSF9 and HLA-A pre-mRNA would detected by molecular interaction technique to elucidate the molecular mechanism of SRSF9 regulating HLA-A gene alternative splicing. This project will reveal the new mechanism of RA autoantigen presentation, provide a potential target for the development of new drugs to block the autoantigen presentation, and also a provide new ideas for RA research.