Tim-3/gal-9信号通路介导Th17/Treg细胞在造血干细胞移植后aGVHD中的调控作用研究

Both Th17 and Treg cells participate in immune responses in allogeneic stem cell transplantation(allo-HSCT), and preliminary experiments show the imbalance of Th17/Treg play roles in the process of acute graft-versus-host diseases(aGVHD). Tim-3, expressed in the surface of Th17 and Treg cells, regulates the function of the two cells and adjust the proportion of Th17/Treg by combining with its ligand, gal-9, which is clear, while there is no in-depth study in the biological significance in aGVHD. In this project, we provide Tim-3/gal-9 signal as main line, Th17/Treg cells which is regulated by Tim-3/gal-9 as breakthrough point, aGVHD patients after allo-HSCT as research objects. Through experimental methods including FACS, ELISA, gene chip, immune coprecipitation, functional test of immune cells, and animal model, the expression of Tim3+CD4+IL-17+T, Tim-3+CD4+Foxp3+T subsets, and proteins and cytokins involved are detected. Considering the changes of Th17 cell, Treg cell subsets, the mechanisms of regulatory function by Tim-3/gal-9 signal pathway are clarified, the relationship between the pathway and aGVHD are investigated, hence provide new ideas for clinical interventions in this kind of diseases.

Th17和Treg细胞参与了移植免疫应答，预实验证实在aGVHD患者中两者比例出现失衡。Tim-3表达于Th17和Treg细胞表面，与配体gal-9结合，调节上述两种细胞的功能及比例，但此过程如何调节aGVHD尚不清楚。申请人拟以Tim-3/gal-9为主线，以受其调控的Th17/Treg细胞为切入点，以造血干细胞移植后aGVHD患者为研究对象，通过流式细胞术、ELISA、基因芯片、免疫共沉淀、免疫细胞功能实验和动物模型等方法研究Tim-3+Th17、Tim-3+Treg细胞亚群变化及相关基因、蛋白、细胞因子的表达，并进一步检测体内外阻断后上述指标的变化，阐明Tim-3/gal-9在调节该细胞亚群的机理，探讨该信号异常对aGVHD发生发展的作用，进而为该类疾病的临床干预提供新思路。

造血干细胞移植后aGVHD是影响患者生存的主要并发症，进一步探索新的干预机制非常重要。Th17和Treg细胞参与了移植免疫应答过程，是参与aGVHD发生发展的重要免疫细胞。本项目以造血干细胞移植后GVHD患者为研究对象，检测了患者不同病程以及不同组织来源CD4+IL17+ T细胞, CD4+CD25+CD127±T亚群的变化，Tim-3的基因和蛋白水平改变，相应的细胞因子改变，阐明Tim-3/galectin-9在该细胞亚群的表达特性及机理。此外，从临床角度探讨该信号异常与GVHD发生发展的相关性，进一步构造了小鼠的aGVHD模型，通过阻断和激活Tim-3/galectin-9信号，观察Th17和Treg细胞的改变，及其相应细胞因子的变化，进一步证实通过干预该信号通路，可以有效的干预aGVHD的发生，为aGVHD的预治提供了新的临床手段。