【摘要】 目的研究CD4+CD25+Tr细胞及其相关基因Foxp3与大鼠肝移植自发免疫耐受的关系。方法双袖套法建立大鼠原位肝移植模型;密度梯度离心法分离肝内淋巴细胞;免疫磁性分离法(MACS)分选CD4+CD25+T细胞,流式细胞术(FCM)检测所得细胞纯度。体外细胞增殖试验研究CD4+CD25+T细胞的免疫抑制作用。Western蛋白印迹法检测CD4+CD25+T细胞Scurfin蛋白表达。结果自发耐受组大鼠移植肝内CD4+CD25+Tr细胞含量显著高于急性排斥组。混合淋巴细胞反应中,LEW大鼠的脾细胞比DA大鼠自身的脾细胞更能刺激CD4+CD25+T细胞的增殖。CD4+CD25+T细胞能抑制CD4+CD25-T细胞的增殖,当加入外源性IL-2(200U/ml)时,该抑制作用被逆转。结论转录因子Foxp3介导的CD4+CD25+Tr细胞的免疫抑制作用可能是诱导大鼠肝脏移植自发免疫耐受的机制之一。更多还原

【Abstract】 Objective To investigate the role of intrahepatic CD4~+CD25~+ T regulatory cells and Foxp3 gene in the natural tolerance in rat liver transplantation.Methods The!orthotopic liver transplantation models of inbred rats(LEW and DA rats) were established with double-sleeve technique and the models were divided into two groups: tolerance group(TOL group, LEW-to-DA) and rejection group(REJ group, DA-to-LEW). The intrahepatic lymphocytes from each group were isolated by using density gradient centrifugation. CD4~+CD25~+ T cells were isolated by magic cell sorting system (MACS) and identified by flow cytometry (FCM). CD4~+CD25~+ Tr cells suppression on the proliferation of CD4~+CD25~- T effector cells were analyzed by cell proliferation assay in vitro. Western blot was used to detect Scurfin protein expression of CD4~+CD25~+ Tr cells. Results CD4~+CD25~+ Tr cells developed significantly greater in the TOL group than in the REJ group. In vitro, the spleen cells from LEW rats can irritate the proliferation of CD4~+CD25~+ T cells more obviously than the syngeneic spleen cells. CD4~+CD25~+ T cells could suppress the proliferation of CD4~+CD25~-T cells, but the inhibition was reversed by exogenous IL-2(200 U/ml). Conclusions The immune suppression function of CD4~+CD25~+ Tr cell, mediated by Foxp3 gene, is one of the mechanisms in liver transplantation tolerance.更多还原