应用供体抗原特异性CD4+CD25+Treg细胞延长大鼠移植肾的存活

背景:随着磁分选技术的完善,体外分选、扩增足量的对移植抗原具有特异性的细胞已成为可能,但就其在体内应用剂量及免疫耐受的效能问题目前鲜有报道.目的:探索供体抗原特异性CD4+CD25+Treg细胞在体内应用诱导移植免疫耐受的量效关系.方法:以SD大鼠为供体、Wistar大鼠为受体,建立同种异体肾移植动物模型;体外分选、富集Wistar大鼠脾脏CD4+CD25+Treg细胞,并诱导其对SD大鼠供体抗原的特异性表型;根据不同数量(2×105、5×105、1×108、2×106)供体抗原特异性CD4+CD25+Treg细胞在肾移植中单剂量尾静脉注射,并以未注射组为对照.术后15 d分析移植肾脏存活状况.术后4,9,15 d采血检测各组肌酐水平,同时进行移植肾脏病理检查,按照Banff Schema标准进行诊断,并根据Watanabe的方法进行半定量评分.结果与结论:术后15 d内对照组死亡率最高83.3%,2×105组次之66.7%,2×106组为58.3%,5×105组为33.30%,1×106组则全部存活;各实验组术后4,9,15 d血肌酐水平均明显低于对照组(P<0.05,P<0.01);术后第9,15天,2×105组、5×105组血肌酐水平均明显高于1×106组、2×106组(P<0.05);术后第4,9,15天移植肾脏病理检查的半定量评分结果显示,各时间段5×105组、2×105组与对照组间差异无显著性意义,各时间段1×106组与2×106组优丁二对照组(P<0.05).结果初步证实供体抗原特异性CD4+CD25+Treg细胞受体内应用能够改善大鼠移植肾功能,延长移植肾存活时间,1×106为相对理想的单次应用剂量.

Donor antigenic specificity CD4+CD25+Treg cells prolong the survival of allograft kidney in rats

BACKGROUND: the development of magnetic separation technique,it is feasibility to in vitro sort and amplify CD4+CD25+Treg cells for transplantation; however,the application dosage and immune tolerance have been less reported yet.OBJECTIVE: To investigate dose-effect relationship of CD4+CD25+Treg cells during allograft transplantation.METHODS: SD rats which were considered as the donors and Wistar rats as receptors were used to establish allograff kidney transplantation models.CD4+CD25+Treg cells were separated from splenic cells of Wistar rats and induced phenotype of donor antigenic specificity in vitro.According to the quantities of CD4+CD25+Treg cells injecting through tail vein during the operation of allograft kidney transplantation,models were rolled into four experiment groups: group 1(2×105),group 2(5×105),group 3(1×106),and group 4(2×106).The models out injection were considered as controls.Survival status of kidney was detected at day 15 postoperatively; creatinine level and pathological changes were detected at days 4,9 and 15 according to Banff Schema diagnostic standard; semi-quantitative scores were measured Watanabe technique.RESULTS AND CONCLUSION: The death rate was the highest in control group(83.3%),and then group 1(66.7%),group 4(58.3%),and group 2(33.3%); but rats in the group 3 were all survival.Creatinine level in experimental groups was significantly less than control group at days 4,9,and 15 postoperatively(P<0.05,P<0.01); the creatinine levels in the group1 and group 2 were significantly greater than in the group 3 and group 4 at days 9 and 15 postoperatively(P<0.05),Semi-quantitative scores demonstrated that there was no significant difference between group 2 and group 1; but the scores in the group 3 and group 4 were significantly greater than control group(P < 0.05).The results indicated that CD4+CD25+Treg cells could improve kidney function following transplantation,and prolong survival time of transplanted kidney.The 1×106 was the best dosaae for application.