同种移植排斥反应中T细胞间接识别途径作用的研究

目的　CD+ 4T细胞通过间接识别途径识别MHC Ⅰ类移植抗原而活化已在离体实验中得到证实 ,但体内实验尚未见报道。方法　bml小鼠 (H 2Kbm1∶Kbm1,Db,Ⅰ Ab)的皮肤片分别移植到①B6小鼠 (H 2 b∶Kb,Db,Ⅰ Ab,n =8) ;②B6CD / 8小鼠 (H 2 b∶Kb,Db,Ⅰ Ab,CD / 8,n =8) ;③用抗CD4 抗体处理的B6CD / 8小鼠体上 (n =8)。观察移植皮肤的生长时间 ;用流式细胞仪 (FACScan)观察各组小鼠内T细胞亚群的变化。各组数据用分组或配对t检验进行数据统计。结果　尽管CD / 8小鼠体内未发现CD+ 8T细胞存在 ,但很快排斥了bm1皮肤移植片 (2 1 9d± 1 9d) ;而用抗CD4 抗体处理的B6CD / 8小鼠却长时间接受bm1皮肤移植片 (>47 5d± 3 8d) ;用流式细胞仪发现CD+ 4T细胞明显增殖活化并被抗CD4 抗体抑制。结论　CD+ 4T细胞通过间接识别途径活化并导致同种相异MHC Ⅰ类移植物的排斥。

Contribution of T cell indirect recognition pathway in initiating allograft rejection in vivo

AIM The generation of knockout mice with targeted gene disruption has provided valuable tools for studying the immune response. The CD / 8 mice generated by this technique did not express CD 8 antigen; 99% peripheral T cells in lymph nodes and spleens was CD + 4 T cells. Here we use of CD 8 knockout mice to examine the role of CD + 4 T cell initiating MHC Ⅰ disparate allograft rejection in vivo. METHOD The mice bm1 (H 2 b∶K bm1 ,D b,Ⅰ A b)skin graft was grafted to B6 CD / 8 mice (H 2 b∶K b,D b,Ⅰ A b,CD / 8)(n=8);For experiment group, anti CD 4 antibody were used to deplete the CD + 4 T cells in B6 CD / 8 mice with bm1 skin grafts (n=8). Skin grafts survival was examined; Flowcytomete (FACScan) were measured. Statistics were done with students test. RESULT The bm1 skin grafts were rejected by B6 CD / 8 mice 〔(21 9±1 9)d〕; by contrast, B6 CD / 8 experiments depleted of CD + 4 T cells in vivo accepted the MHC Ⅰ disparate skin 〔>(47 5±13 8)d〕. The generation of CD + 4 T cells was detected, and it was also reduced by anti CD 4 antibody. CONCLUSION Indirect allo recognition path plays an important role in trasplantation reiection.