泛素化结合酶UBE2L3调节NK细胞TIM-3表达在SAA免疫发病机制中的作用

In recent years, studies have confirmed that severe aplastic anemia (SAA) is a bone marrow-targeted autoimmune disease mediated by hyper-activated effector T cells (CTL). Our previous studies have found that NK cells play a protective role by inhibiting CTL in the pathogenesis of SAA, and related to the abnormal expression of TIM-3. In previous studies, our proteomic results have shown that ubiquitin conjugating enzyme UBE2L3 expression increased in NK cells from SAA patients. During further validation experiments, we found that UBE2L3 activity is closely related to TIM-3 expression in NK cells. In this study, we aimed to investigate the role of UBE2L3 in regulating TIM-3 expression in NK cells in the pathogenesis of SAA. (1) To analyze the effect of UBE2L3 on TIM-3 expression in NK cells, function of NK cells and its correlation with the immune status of SAA patients; (2) in vitro and SAA mice model to elucidate the changes of TIM-3 expression in NK cells, function of NK cells and downstream activated immune response using UBE2L3 interference; (3) to screen differential signaling pathways of the interaction between NK cells and CTL mediated by UBE2L3 using ITRAQ. Through the above studies, we try to further clarify the immune pathogenesis of SAA and provide a novel target in the treatment of SAA.

SAA是一种T细胞功能亢进、损伤骨髓造血的免疫性疾病。我们既往研究显示，NK细胞在SAA免疫反应中发挥保护性作用，可抑制亢进的T细胞，而TIM-3表达异常与此作用密切相关。申请人近年来主要参与SAA免疫机制研究，在对NK细胞的蛋白质组学中发现，SAA患者NK细胞泛素化结合酶UBE2L3表达升高，其活性与NK细胞TIM-3表达相关。本课题拟在前期工作基础上，以SAA患者与小鼠模型为研究对象，对UBE2L3调控NK细胞TIM-3表达在SAA免疫发病机制中的作用进行深入探索。分析SAA患者NK细胞UBE2L3水平对其TIM-3表达、细胞功能的影响，及其与患者免疫状态的相关性；体外实验及小鼠模型阐明干扰NK细胞UBE2L3对调控其TIM-3表达、细胞功能及下游免疫反应的影响；iTRAQ技术进一步筛选干扰UBE2L3对调控NK细胞与CTL相互作用的机制，以求进一步明晰SAA发病机制并寻找新治疗靶点。

SAA是一种T细胞功能亢进、损伤骨髓造血的免疫性疾病。我们的既往研究显示，NK细胞在SAA免疫反应中发挥保护性作用，可抑制亢进的T细胞。本课题在此基础上，以SAA患者与小鼠模型为研究对象，检测SAA患者外周血NK细胞TIM3表达水平，探讨TIM3+NK与TIM3-NK细胞功能活性差异及其对下游免疫反应的影响，阐明NK细胞泛素化结合酶UBE2L3对其TIM3表达及细胞功能的影响，证实了SAA患者NK细胞TIM3表达减低，NK细胞功能增强，抑制了SAA患者异常免疫激活，在SAA的发病中起保护性作用，而泛素化结合酶UBE2L3可能参与调节NK细胞TIM3的表达。本课题进一步补充了SAA的免疫发病机制并为提高SAA免疫抑制治疗提供了新思路。