门静脉输注供者脾细胞诱导的供者特异性免疫低反应性

目的 探讨经门静脉输注供者脾细胞能否诱导皮肤移植小鼠产生供者特异性的免疫低反应性及其可能机制.方法 取Balb/c小鼠,随机分为空白对照组(经小鼠门静脉输注RPMI 1640培养液)、受者脾细胞组(经小鼠门静脉输注Balb/c小鼠脾细胞)、供者脾细胞组(经小鼠门静脉输注C57BL/6小鼠脾细胞)、空白移植对照组(经小鼠门静脉输注RPMI 1640培养液,7 d后移植C57BL/6小鼠的皮肤)、实验对照组(经小鼠门静脉输注Balb/c小鼠脾细胞,7 d后移植C57BL/6小鼠的皮肤)、实验组(经小鼠门静脉输注C57BL/6小鼠脾细胞,7 d后移植C57BL/6小鼠的皮肤)以及第三方移植组(经小鼠门静脉输注C57BL/6小鼠脾细胞,7 d后移植C3H小鼠的皮肤).记录空白移植对照组、实验对照组、实验组和第三方移植组移植皮肤的存活时间,并观察移植皮肤的病理学变化;脾细胞输注后7 d,分别获取空白对照组、受者脾细胞组和供者脾细胞组小鼠的外周血、脾脏和肝脏,用流式细胞仪测定样本中CD4+CD25+Foxp3+调节性T淋巴细胞(CD4+CD25+Foxp3+Treg细胞)的比例.结果 实验组移植皮肤的存活时间为(19.8±4.6)d,明显长于空白移植对照组、实验对照组和第三方移植组,但仍未达到长期存活.皮肤移植后7 d,空白移植对照组和实验对照组的移植皮肤呈现重度急性排斥反应的病理学改变,而实验组移植皮肤呈现中度急性排斥反应的病理学改变.供者脾细胞组外周血、肝脏和脾脏中CD4+CD25+Foxp3+Treg细胞比例明显高于空白对照组和受者脾细胞组.结论 门静脉输注供者脾细胞可特异性地延长供者皮肤移植物的存活时间,减轻移植物的排斥反应,该效应可能与受者体内的CD4+CD25+Foxp3+Treg细胞增加有关.

The role of CD4+ CD25+ Foxp3+ Treg in the immune tolerance induced by portal vein injection of donor splenocytes

Objective To study the roles of CD4+ CD25+ Foxp3+ regulatory T cells (Treg) in the immune tolerance induced by portal vein injection of donor splenocytes. Methods C57BL/6 mice were selected as donors and Balb/c mice as recipients. The recipients were divided into 7 groups at random. Recipients in blank control group received RPMI 1640 via portal vein injection, and those in the donor-splenocytes group and recipients-splenocytes group received splenocytes of C57BL/6 mice and Balb/c mice through portal vein injection, respectively. The recipients in blank transplant group received RPMI 1640 via portal vein injection,and 7 days later skin of C57BL/6 mice was transplanted.The recipients in experimental control group and experimental group received splenocytes of Balb/c mice and C57BL/6 mice through portal vein injection, and 7 days later skin of C57BL/6 mice was transplanted. The recipients in third-party transplant group received splenocytes of C57BL/6 mice through portal vein injection, and 7 days later skin of C3H mice was transplanted. The survival time and histological changes of donor skin were observed. Flow cytometry was applied to detect the proportions of CD4+ CD25+ Foxp3+ Treg in the blood, spleen and liver in each group. Results The survival time of donor skin allograft was significantly longer in experimental group (19. 8±4. 6 days) than in blank transplant group, experimental control group and third-party transplant group, but did not maintain long-term survival. Seven days after transplantation,histological changes showed that the rejection was milder in experimental group than in blank transplant group and experimental control group. The proportion of CD4+ CD25+ Foxp3+ Treg was significantly higher in donor-splenocytes group than in recipients-splenocytes group and blank control group. Conclusion Portal vein injection of donor-derived splenocytes can prolong the survival time of the skin allograft specifically, and reduce its rejection. In this process,the CD4+ CD25+ Foxp3+ Treg may play a role in the mechanism.