运动对ICOS的诱导表达作用及其生物学功能研究

The Expression and Biological Function of ICOS Molecule in Exercise

目的:立足于运动训练对运动员免疫功能的影响,就运动对ICOS分子表达的诱导作用及其生物学功能做一探索性研究。方法:随机抽取17～23岁运动员共35名为实验对象,建立人体运动免疫研究实验模型;运用密度梯度细胞分离法,获得运动员运动前、期间、运动后不同时段的外周血PBMC;运用细胞体外培养技术、MTT法和流式细胞术、RT-PCR技术,体外检测各时段T细胞活化增殖程度、T细胞亚群变化及T细胞表面ICOS及T细胞ICOS mRNA表达水平;将ICOS特异性配体GL-50与上调表达ICOS分子的T细胞体外共育,5天后ELISA法检测细胞培养液中IL-10水平,同时检测运动员运动前后血清IL-10、LI-2、IFN-γ水平。结果:运动可激发T细胞活化增殖,导致T细胞亚群变化;运动可诱导活化T细胞上调表达ICOS和ICOSmRNA;ICOS/GL50共刺激信号可刺激T细胞合成分泌IL-10;持续4用运动训练后,运动员血浆IL-10水平显著提高,IL-2、IFN-γ水平明显下降。结论:长期运动应激可诱导活化T细胞上调表达ICOS分子;ICOS分子具有加强T细胞合成分泌IL-10、诱导Th2细胞增殖分化的重要功能;ICOS/GL50共刺激信号诱导IL-10分泌、Th1/Th2失衡,是运动后机体对感染性疾病易感性增高的"运动性免疫抑制"现象的重要免疫学基础。

This paper makes explosive study on the characteristics of inducible co-stimulatory molecule （ICOS） expressions and its biological functions on T-cells in peripheral blood cells from the athletes after persistent hard training in order to reveal the assuring effects of sports training on immune function. Method 1 ）Establishing the experimental model of effects of sports training on immune system in 35 athletes aged 17-23 years old who were in persistent hard training for 4 weeks; 2）Obtaining the peripheral blood monocyte cells （PBMC） and T cells by means of density-gradient centrifugation pre-, duration and post-training respectively; 3） Testing the degrees of T cell activation and reproduction, the change of T cell subsets and the expression levels of ICOS and ICOSmRNA on T cells by using of the techniques of 3-（45dime thyl- thiazol-z-yl）-25- diphenyltetr azolium bromide （MTT）, immunoflurescence mark, flow cytometry and reverse transcript polymery chain reaction （RT-PCR）; 4）Observing the changes of levels of cytokines IL-10, IL-2 and INF-y in the cultured cells stimulated by the specific ligand GL50 in vitro for five days by means of using the ELISA. Results 1）Comparing to stage of pre-hard training, the T cells post-persistent intense training for 4 weeks were significantly more reproductive and active combined with the significant up-regulating characteris- tics of ICOS and ICOS rnRNA expression on the T cell＇ s surfaces, at the same time, the T cell subsets showed different changes. 2）ICOS/GL50 could stimulate directly on T cell to produce and secrete cytokine IL-10.3）After intense training for 4 weeks, the levels of cytokine IL-10 in blood plasma increased, at the same time, the levels of cytokines IL-2. IFN-y decreased. Conclusion 1） Intense training could induced ICOS expression on activated T cells. 2 ） ICOS could stimulate directly T cell to produce cytokine IL-10 and, therefore, to enhance the differentiation from CD4＋ cell to Th2 cell, finally, to result in the unbalance of Thl/Th2 which enhances Th2 induced humoral immunity. 3）The change of immune function could be closely related to the activation of T cell, up-regulating expression of ICOS, increase the secretion of IL-10, the differentiation of Th2 cell under persistent stress condition.