TGF-β1诱导的调节性T细胞体内输注延长小鼠皮肤移植物存活

目的 利用TGF-β1体外诱导naYve T细胞分化为凋节性T细胞(Treg),通过体内输注延长小鼠皮肤移植物存活时间,并研究其相关机制. 方法 根据诱导条件不同分为3组:对照组(加入IL-2培养的C57BL/6小鼠T细胞)、MLR组(即混合淋巴细胞反应组,经同种抗原刺激活化的C57BL/6小鼠T细胞)和TGF-β组(经同种抗原刺激活化的C57BL/6小鼠T细胞,同时加入5.0ng/ml TGF-β1诱导).利用FACS检测CD4+CD25+T细胞比例,并用RT-PCR检测Foxp3的表达水平.建立小鼠皮肤移植模型,并于第0、l、2和3天输注上述细胞,观察皮肤移植物存活时间.术后第9天,取部分受鼠行移植物病理检测,用FACS检测脾脏中THl、TH2和CD4+CD25+Treg比例,并用Alamar Blue法检测淋巴细胞增殖能力. 结果 TGF-β组中CD4+CD25+T细胞比例高于对照组和MLR组(P<0.05),且其高表达Foxp3.将培养的细胞输注给受鼠后发现,输注MLR组细胞的受鼠其移植物平均存活时间(mean survival time,MST)为(9.4±1.3)d,低于对照组(P<0.05);而输注TGF-13组细胞小鼠MST为(22.8±1.9)d,较对照组和MLR组明显延长(P<0.05).病理检测亦显示TGF-β组受鼠移植物结构完整,无明显淋巴细胞浸润.FACS结果显示TGF-β组小鼠体内TH1细胞(CD4+TIM-3+)比例低于对照组和MLR组(P0.05),但低于对照组(P<0.05);而且TGF-β组中CD4+CD25+Treg比例明显高于对照组和MLR组(P<0.05).用Alamar Blue法检测受鼠外周淋巴细胞增殖活性显示,TGF-β组受鼠淋巴细胞增殖能力被明显抑制,低于对照组(P<0.05). 结论 TGF-β1可诱导T细胞分化为具有抑制能力的Treg将诱导后的细胞进行过继输注可使小鼠体内CD4+CD25+Treg比例升高,同时抑制TH1和TH2细胞分化扩增,并使得外周淋巴细胞增殖能力减弱,从而延长小鼠皮肤移植物存活时间.

Transfer of regulatory T cells induced by TGF-β1prolonged the skin-graft survival in mice

Objective To study the probability of transferring the regulatory T cells induced by TGF-β1 to prolong the allograft survival and the mechanisms involved.Methods According to the different culture conditions.three experimental groups were established:control group(T cells from C57 BL/6 mice cultured with II-2),MLR group(T cells from C57BL/6 mice activated by alloantigen)and TGF-βgroup(T cells from C57BL/6 mice activated by alloantigen and cultured with 5.0 ng/ml TGF-β1).After the culture,the ratio of CI4+CD25+T and the Foxq3 expression were measured by FACS and RT-PCR,respectively.On 9th day,the pathologic analysis was performed and the ratios of TH1,TH2 and Treg and the proliferation of lymphocytes were measured.Results The ratio of CD4+CD25+T in TGF-β group was higher than that in control group and MLR group(P<0.05),and Foxp3 was expressed in CD4+CD25+T cell from TGF-βgroup.After transferring ofthe cells,the allografi survival time in TGF-β group was prolonged and its mean survival time(MST)was(22.8±1.9)d,which was longer than that in MLR group and control group (P0.05),lower than that of control group(P<0.05). And the ratio of CD4+CD25+T in TGF-β group was higher than that in control and MLR group obviously(P