基于光亲和标记策略探测四氮唑化合物促进 Treg 细胞分化防治自身免疫性疾病的作用靶标

Development of small molecular drugs for autoimmune disease has become a key problem that need to be solved urgently in clinic, but lack of targets was the lethal factor. So,target identification of active small molecular drugs for autoimmune disease has great guiding significance for drug research later. In preliminary studies, we haved developed a series of tetrazole compounds, and the activity results showed that the tetrazole compounds had immunoregulatory activities in varying degrees and the compound CK02P38 had the best, which can raised the level of Foxp3 in 96 h continually. Compared with the clinic drug trans-retinoic acid, CK02P38 has obvious advantages which had more lasting efficacy and different mechanism. Furthermore，The Treg cells induced by CK20P38 could inhibited effective T cells. However, the targets and mechanism of CK20P38 in immunoregulatory activities were not clear. now, we will design and synthesize a series of active probes based on CK02P38, and detect the targets of CK02P38,which will clarify the mechanism of CK02P38 that regulated differentiation of Treg and provide valuable scientific information for development small molecular drugs for autoimmune disease.

治疗自身免疫性疾病小分子药物的研发是目前临床亟待解决的关键问题之一，而尚无成药性靶标是制约小分子药物先导化合物发现的瓶颈。因此，探索活性小分子化合物治疗自身免疫性疾病的潜在作用靶标，对后续的药物研发具有重大的指导意义。前期研究中发现四氮唑类化合物CK20P38具有显著的免疫调节活性，可在96h内稳定地上调Treg特征性转录因子Foxp3的表达水平。初步的作用机制研究表明，CK20P38具有与临床药物atRA不同的免疫调节作用机制，其诱导的Treg具有抑制效应T细胞的功能，然而具体的作用靶标及作用机制尚不清楚。本项目拟在前期工作基础上，以CK20P38为先导物，设计合成系列CK20P38的活性分子探针，并利用ABPP技术中的光亲和标记策略(PLA)探测其潜在的作用靶标，阐明其作用机制，为研发治疗自身免疫性疾病的小分子药物提供科学依据。

诱导性调节性T细胞（iTreg）可通过抑制效应T细胞来抑制相应的免疫功能。研发诱导 iTreg 细胞分化的小分子免疫调节剂可作为防治免疫过强相关疾病的有效策略。本研究采用基于报告基因小鼠脾脏淋巴细胞的 iTreg 细胞分化模型筛选到了诱导 iTreg 分化的四氮唑类光亲和化合物，CK02P38。随后，我们以 CK02P38 为母体化合物，成功构建了活性四氮唑光亲和小分子探针，并基于活性蛋白质组分析（ABPP）技术探测了其调节 iTreg 分化的潜在作用靶标 Samhd1、Ikaros 和 Cap1。本研究有望阐述调节iTreg 分化的新机制，并为免疫性疾病的药物研发提供先导化合物。