口服抗原对同种异体移植免疫反应的影响

将Wistar大鼠预先喂养同种异基因SD大鼠脾细胞7天，然后接受SD大鼠的皮肤移植，7天后，再接近SD大鼠的心脏移植，观察口服抗原后体外混合淋巴细胞培养（MLC）、体内迟发型超敏反应（DTH）以及心脏存活时间。口服抗原后，体外MLC及体内DTH反应均出现明显的抗原特异性降低，口服抗原组大鼠并接近供者皮肤致敏后的心脏移植存活时间达到7天，与对照组未致敏鼠的心脏移植存活时间一致；而未口服抗原组接受皮肤致敏后的心脏移植存活时间不超过2天。提示口服抗原可以使异基因抗原的特异性免疫应答降低，延长移植存活时间，阻皮肤移植物的事先致敏反应的发生，并使加速排斥反应时间明显延迟。

STUDY ON EFFECTS OF ORAL ADMINISTRATION OF MAJOR HISTOCOMPATIBILITY ANTIGENS ON ALLOIMMUNE RESPONSE

To study the effects of oral administration of antigens on the alloimmune response, Wistar rats were pre-fed with allogeneic SD rat splenocytes for 7 days. In an accelerated allograft rejection model, Wistar rat were presensitized with SD skin allografts 7 days before challenging with SD cardiac allografts. The mixed lymphocyte response in vitro and delayed type hypersensitivity response in vivo after oral administration of antigens were examined. The survival of cardiac allograft in sensitized animals(including feeding group and control group) were observed. Lymphocytes from Wistar rats that had been pre-fed with allogenetic splenocytes exhibited significant antigen-specific reduction of the mixed lymphocyte reoponse in vitro and delayed-type hypersensitivity response in vivv when compared with un-fed controls. While sensitized control animals rejected their cardiac allograts within 2 days.animals pre-fed with SD splenocyles maintained cardiac allograft survival up to 7 days, a time similar to that observed in unsensitized control recipients. Therefore, orally administered alloantigen can down-regulate the immune response to histocompatibility antigens,prolong the survival of allografts,prevent sensirization by skin grafts, and delay the occurrence of accelerated rejection of vascularized cardiac allografts.