大鼠骨髓间充质干细胞对同种异体T淋巴细胞的作用及其机制

目的:探讨骨髓间充质干细胞(MSCs)在混合淋巴细胞反应(MLR)中对同种异体T淋巴细胞免疫应答反应的影响,并探讨其作用机制。方法:建立MSCs和同种异体T淋巴细胞共培养体系,反应体系总量250μl。以SD大鼠的脾T淋巴细胞为刺激细胞,以W istar大鼠的脾T淋巴细胞为反应细胞,分为6组。组Ⅰ:对照组,1×105刺激细胞和1×105反应细胞共同培养;组Ⅱ:1×105反应细胞与1×104SD大鼠的MSCs共同培养;组Ⅲ:1×105刺激细胞和1×105反应细胞并加入1×104SD大鼠的MSCs共同培养;组Ⅳ:细胞种类及数量同组Ⅲ,另加1-甲基色氨酸(1-MT)(终浓度1 mol/L);组Ⅴ:细胞种类及数量同组Ⅲ,另加植物刺激素(终浓度2μg/m l);组Ⅵ:每孔加入反应细胞和刺激细胞各1×105及MSC 1×103。混合培养120 h,结束培养前13 h,每孔加入3H-TdR 20μl,以液闪测定仪测定各组的每分钟脉冲数。反相高效液相色谱法检测MSCs和MLR共培养体系中色氨酸含量。结果:MSCs可以抑制混合淋巴细胞培养体系中T淋巴细胞增殖,并呈现出剂量依赖关系;同时MSCs和MLR共培养体系中色氨酸含量明显降低。1-MT可以阻断这一作用。结论:MSCs在体外可抑制同种异体T淋巴细胞的免疫应答,吲哚胺2,3双加氧酶参与了这种免疫抑制作用。

Effect of rat bone mesenchymal stem cells on allogeneic T cell

Objective：To investigate the immunogenity and immune regular ability of mesenchymal stem cells（MSCs） derived from rat bone marrow in mixed lymphocyte culture.Methods：MSCs and mixed lymphocyte reaction（MLR） cultures were set up.Splenic lymphocytes from SD rats were used as stimulator cells,and splenic lymphocytes from Wistar rat as responder cells.The study was composed of 6 groups.Group Ⅰ,the control group,was co-cultured with 1×105 stimulator cells and 1×105 responder cells,group Ⅱwith 1×104 MSCs from SD rats with the same amount of stimulator cells as group Ⅰ,group Ⅲ with 1×104 MSCs from SD rats and the same amount of stimulator and responder cells as group Ⅰ,group Ⅳ with 1×104 MSCs from SD rats and the same amount of stimulator and responder cells as group Ⅰ plus 1-methyltryptophan（1-MT）,group V with 1×104 EPC from SD rats and the same amount of stimulator and responder cells as group Ⅰ plus phytohemagglutinin（PHA）as a mitogen,and group VI with 1×103 MSCs and the same amount of stimulator and responder cells as group Ⅰ.The culture time was 120 hours for each group.The number of lymphocyte in each group was calculated with a liquid scintillation counter.The MSCs and the content of tryptophane were determined by TRP-HPLC.Results：MSCs inhibited T-lymphocytes proliferation of MLR culture in a dose-dependent manner.The content of tryptophan decreased greatly in MSCs and MLR cultures.1-MT reversed the effect of MSCs.Conclusions：MSCs could suppress T lymphocyte responses via IDO enzyme activity.