大鼠Ⅲ°烧伤同种异基因混合皮肤移植后免疫应答初析

同种异基因混合皮肤移植物是少量自体皮与大张异体皮的嵌合体.在大面积Ⅲ°深烧伤治疗中取得非常好的效果。本文以大鼠混合植皮模拟实验为基础,动态分析了移植后4、7、14、21和28d免疫应答的变化。分别以大张异体皮移植组和烧伤组作对照,结果发现混合皮肤移植后一定程度上降低了机体对移植物的免疫反应强度,但在移植早期仍然显示适度的反应能力。移植后MLR有所增强,并在第7天达到显著水平,CD4~+T峰值出现偏早在第7天(P<0.05);而CDS~+T出现较迟在第14、21天(P<0.05)。CD8~+变化趋势与特异性CTL细胸毒性表现一致,而NK细胞毒性则呈相反结果。提示混合皮肤移植后,由不一致的同种异基因移植物引起的全身反应并通过CD4~+、CD8~+T再循环在局部的免疫调节以及由KC诱导的局部免疫耐受都可能有利于促进创面愈合,排斥异已达到自身稳定的效果。

A Preliminary Analysis of Immune Responses from the Intermingled Skin-Allografted Rats with Ⅲ°Burn Injury

It has been established that the intermingled skin grafts . in which a sheet of allo-skins was inlaid with a lot of small pieces of auto-skins, could be successfully used to repair the sites of Ⅲ° ?burn injury. It not only accelerates the wound healing, but also eliminates the risks of rejection for the allografts. In this paper, we report the changes of the immune responses on the 4, 7,14 and 28 days after transplantation with the intermingled skin allografts in the rats with Ⅲ°?burn injury. Compared with control of burn-group, the immune responses including MLR and Percentages of CD4+T cells were inhibited or decreased in the first week, followed by a slow recovery. After intermingled skin grafting, a enhanced alloresponse ( MLR ) appeared in the first week. Simultaneously, there was a peak of the CD4+T cell counting on the 7th day. But a similar peak for CD8+T cell frequencies emerges latter from 14 to 21 days. In addition,disparate cytotoxic-ities were observed between CTLs and NKs for four weeks after grafting, i. e. the former went up and the latter went down. Based on these results, together with our previous observations that the auto-epithelial cells (AEC) could induce immune tolerance in a system of mixed epithelial and lymphocyte culture (MELC) , we deduce that both the cellular immune responses initiated by allograft-ing and the immune tolerance induced by AEC may contribute to the wound healing and the rejection of grafts in derma.