用人免疫活性细胞重建免疫抑制后猪的免疫系统

Immune Reconstitution in Immunosuppressed Pigs with Human Immune Competent Cells

为探索用人免疫活性细胞重建猪免疫系统，用以测试活体动态猪→人异种移植免疫反应性。将中国内江猪经化疗行免疫成分摧毁后随机分为对照组、腹腔组和静脉组，每组各5只。腹腔组和静脉组分别于免疫成分摧毁后7天经腹腔和静脉注入人骨髓及脾细胞悬液。结果显示对照组长期存活，腹腔组存活3～54天，静脉组存活15小时～60天。三组在给药后7天，外周血白细胞降至最低，为给药前的1％～10％，而血小板、血红蛋白变化不大。腹腔组和静脉组白细胞计数恢复较对照组缓慢，血小板、血红蛋白差别不大。输入人细胞后1天、7天、60天，腹腔组和静脉组外周血细胞流式细胞仪检测，离心涂片免疫组化染色，均发现人细胞存在。脾、肺中有人类细胞浸润。因此认为，对免疫抑制的猪植入人骨髓及牌细胞，可使人细胞在猪体内形成嵌合，有发生异种移植物抗宿主病的可能，可为研究猪-人异种移植免疫反应性提供更好的动物模型。移植细胞时经腹腔注射可避免对植入细胞的细胞毒作用，可能优于静脉注入。

To reconstitute the immune system of the pig with human immune cells after destroying or suppressing it, so that the transplant immunoreactivity between human and pig could be monitored in vivo. Fifteen Chinese Neijiang pigs were divided into 3 groups.Group A (n = 5 ) received immunosuppression through intravenous infusion of methotrexate (MTX), myleran and cyclophosphamide (CTX ). Group B received intraperitoneal injection of human bone marrow and spleen cells (HBSC) after the same treatment as group A.Group C (n=5) received intravenous infusion of HBSC after the same treatment as group A. Blood routines and biochemical analysis were monitored. The chimerisms of human cells were supervised through immunohistochemistry of cytospin of peripheral blood from recipient pigs and flowcytometry of the same specimen and immunohistochemistry of frozen tissue sections and paraffin sections. All pigs in group A survived definitely. Group B and C survived 3 days to 54 days and 15 hours to 60 days respectively. The periphera1 white blood cell count (WBCC) of groupA, B and C decreased to the bottom 7 days after drug administration, about 1 %-10% of the normal level. After transplantation, the WBCC of group B and C recovered more slowly than those of group A. Human cells were found in the recipient pigs of group B and C after transplantation through immnunohistochemistry of peripheral blood cytospin and flowcytometry. Infiltration of human cells was found in the spleens and lungs of group C and D through immunohistochemistry. The chimerism of human cells in recipient pigs could be established by transplanting human bone marrow and spleen cells into immunosuppressed pigs. It is possible that XGVHD occurs in the recipient, which offers a novel animal model for studies on immunoreactivity of pig-to-human xenotransplantation. The proportions of human cells in peripheral blood of recipient pigs are low long after transplantation through both intraperitoneal injection and intravenous infusion.