基于前一自然基金重点项目发现小分子Astilbin的靶蛋白核不均一核糖核白A1(hnRNP A1，以下称A1）及其介导的T细胞从活化向凋亡转向事件，本项目拟选择Astilbin的非色酮衍生物，从结构及与A1结合的角度优化A1的小分子配体；在A1条件性敲除小鼠及其T细胞上，观察A1缺失对T细胞活化中Akt、p38通路的影响及细胞从活化向凋亡转换的影响；借助A1的非磷酸化突变S192A、S199A，拟磷酸化突变S192D、S199D和小分子结合位点突变L102A、K179A等，探讨小分子与A1结合的分子基础，建立小分子与A1蛋白功能域相互作用的评价方法；探讨小分子通过A1诱导活化T细胞凋亡的分子机制及其对实验性脑脊髓炎、胶原性关节炎等的治疗作用。为活化T细胞的凋亡转向提供新的理论诠释，明确A1介导的活化T细胞向凋亡转向的事件作为免疫抑制剂新靶标的地位，为新型先导化合物或候选药物的发现打下基础。

Based on our previous findings obtained in the former key project of NSFC, in which we found the target protein hnRNP A1 of Astilbin,a flavone, and elucidated the role of hnRNP A1 in the transformation of T cells from activation to apoptosis, we want to optimize the small molecule ligands of hnRNP A1 in the aspects of compounds' structure and their binding to A1 from the non-chromone derivatives of Astilbin. Then we will examine the effects of dificiency of hnRNP A1 on Akt signaling and p38 signaling in the activation of T cells and on the transformation of activated T cells to apoptosis by using the hnRNP A1-conditional knocked out mice and its T cells; invstigatate the binding domain to hnRNP A1 of the optimized compound using various mutants such as S192A, S199A, S192D, S199D, L102A, and K179A of hnRNP A1; and establish new assays for evaluating compound-hnRNP A1 interaction. Furthermore, we will examine the mechanisms underlying the apoptosis induction of the selected compound via promoting hnRNP A1-mediated apoptosis of activated T cells and the therapeutic efficacy of the compound on experimental autoimmune encephalomyelitis and collagen-induced arthritis. By this project, we will provide a reasonable explanation for the transformation of activated T cells into apoptosis and confirm the role of the event involved in the transformation as the target of novel immunosuppressive agents. This study will also be beneficial for finding a new lead compound or drug canididate.