小鼠异种皮肤移植模型的建立及对免疫抑制药物的药效评价

Establishment of an allogenetic skin transplant model in mice for evaluating immunosuppressive drugs

目的建立小鼠异种皮肤移植模型,以期为免疫抑制药物提供研究模型。方法将C57BL/6小鼠耳部皮肤移植到BALB/c小鼠背部,同时设立同种移植对照(BALB/c小鼠耳部皮肤移植到BALB/c小鼠背部)。选用环孢素A作为抑制异种移植引起的免疫排斥反应的免疫抑制剂,利用该模型评价环孢素A免疫抑制效果。在移植和给药后,对移植排斥评分和移植皮肤的存活率进行统计。移植手术4 d和9 d后,ELISA法对血清中IL-4、IL-12和IFN-γ的水平进行测定。12 d后,计算胸腺和脾脏系数,对脾脏T细胞中CD4^+和CD8^+的比例进行分析,同时将移植皮肤进行病理观察。结果皮肤移植后,排斥评分逐渐增加,移植皮肤的存活率逐渐下降,有明显的水肿、炎症细胞浸润等炎症反应。环孢素A可明显降低移植排斥评分,提高移植皮肤的存活率,使小鼠胸腺和脾脏系数明显降低,高剂量可明显降低脾脏T细胞中CD4^+和CD8^+细胞的比例。同时,环孢素A处理可明显降低移植皮肤的炎症反应。结论小鼠经异种皮肤移植后会出现急性移植排斥反应,环孢素A可有效抑制移植排斥反应,并呈现出明显的剂量依赖性。

Aim To establish an allogenetic mouse skin transplant model,in order to provide a research model for immunosuppressive drugs. Methods Skins from the ears of C57 BL /6 mice were transplanted to the back of BALB /c mice and skin isografts( BALB/c mice to BALB/c mice) were used as control. Cyclosporin A( CsA) was used as a model compound to test the immnosuppresive effect on allogenetic graft rejection. Following the transplation and CsA treatment,the graft rejection score and graft skin survival rate were quantified. Four and nine days after transplantation,serum IL-4,IL-12 and IFN-γ levels were measured using ELISA kits. Twelve days after transplantation,mice were sacrificed. The weight of spleen and thymus was obtained,and CD4^+and CD8^+population of spleenic T cells were analyzed using flow cytometer. Histological features were assessed by hematoxylin-eosin( HE) staining of formalin-fixed,paraffin-embedded graft skins. Results After transplantion,the graft rejection score increased and graft skin survival rate decreased graduallly. Serum IL-12 and IFN-γ levels of allograft mice increased markedly. Compared with those of isograft mice,mice with skin allograft displayed a significant increase in the percentage of the CD8^+T cell subpopulation. Remarkable inflammation,such as edema,inflammatory cell infiltration were observed in allograft mice. Compared with saline treated mice,CsA significantly reduced the graft rejection score and improved survival rate of skin grafts. And also,CsA treated mice had smaller spleen and thymus. Mice that received high doses of CsA had significantly less CD8^+T cells than those treated with saline. Moreover,allograft skins in mice that received CsA had less inflammation. Conclusions Allogenetic mouse skin transplantation exhibits acute graft rejection. CsA can inhibit the rejection in a dose dependent manner.