大鼠口服免疫耐受与皮肤移植的研究

目的利用口服供者脾细胞延长受者大鼠皮肤存活时间，检测调节性T细胞在移植前后的变化，探讨口服免疫耐受的机制。方法以纯系SD大鼠为供者，纯系Wistar大鼠为受者，行异体皮肤移植，将24只受者大鼠随机分为A组（对照组，口服PBS）、B组（每日口服SD大鼠脾细胞1×10^7个），C组（每日口服SD大鼠脾细胞5×10^7个），对受体进行450Rad^60Co照射，然后检测受者外周血及脾脏CD4＋CD25＋、CD8＋CD28-调节性T细胞（Treg），并对受者进行供者脾细胞导管灌胃，每次口服5×10^7个细胞，每日一次，7d后检查迟发型超敏反应（DTH），并行皮肤移植，观察移植皮肤的存活时间，复查Treg两次。结果口服脾细胞后，DTH反应均出现明显的抗原特异性降低；C组的皮肤移植存活时间达到19．17d±1．94d，与前两组比较差异有显著性（P〈0．01）。在口服供体脾细胞延长皮肤移植存活大鼠（C组）的外周血及脾脏中CD8＋CD28-Treg均比口服前明显增高（P〈0．01），并能维持2周以上。结论口服抗原可以引起受者对异基因抗原的特异性免疫反应降低，使受者的皮肤移植存活期延长，CD8＋CD28-Treg在口服免疫耐受的机制中发挥了重要作用。

The Research of Oral Immune Tolerance and Skin Transplantation in Rats

Objective To induce the oral immune tolerance in rats by oral administration of donor spleen cells and investigate the mechanisms of oral tolerance. Methods Skins of SD male rats were transplanted to the Wistar rats. The Wistar ratswere devided into three groups, each group with eight rats： group A, administrated with PBS, group B, administrated with 1× 10^7 spleen cells of SD rats every day, group C, administrated with 5 × 10^7 spleen cells of SD rats every day. All the recipients were administrated 7 days and radiated with 450 Rad 6^0 Co before administration. The CD4 ＋ CD25 ＋, CD8 ＋ CD28 - Treg of the spleen and blood of the recipients were examed for three times： before administration,7 days and 14 days after administration. Results Survival time of allogeneic skin grafts in group A, B and C were 8.33 ＋ 1.03,10.17 ＋ 1.47,19.17 ＋ 1.94 days, respectively ： Compared with group A and B, the survival time of group C were prolong significantly （P 〈 0.01 ）. The DTH responses of group C were decreased significantly compared with group A and B. Conclusions Feeding donor spleen cells can prolonged the survival of skin allografts in rats. CD8 ＋ CD28 - Treg may play a important role in the mechanism of oral immune tolerance.