单核细胞、NK细胞和T细胞在猪-猕猴延迟性异种移植排斥反应中的作用

目的观察单核细胞、NK细胞和T细胞在猪-猕猴延迟性异种移植排斥反应(DXR)中的作用。方法建立湖北白猪-云南猕猴的腹腔异位心脏移植模型，实验分为2组：对照组(n=5)，不使用中华眼睛蛇毒因(Y-CVF)；实验组(n=4)应用Y-CVF完全清除受者体内补体。2组受体猴均采用环孢素A(CsA)，环磷酰胺(CTX)和甲基强的松龙(MP)三联免疫抑制治疗。免疫组织化学方法检测移植心组织中细胞间黏附分子(ICAM)-1、肿瘤坏死因子(TNF)-α、单核细胞、NK细胞和T细胞的表达。结果对照组3个移植心在15～60min内发生超急性排斥反应(HAR)，另2个分别存活22h及6d，移植心均未见明显的炎性细胞浸润及ICAM-1和TNF-α的表达。实验组移植心存活时间分别为8、10、13和13d，移植物浸润细胞中可见大量的单核细胞(50％)，少量的NK细胞(8％～10％)，CD4^ T细胞(15％)和C08^ T细胞(25％)。移植物血管内皮细胞表面出现ICAM-1的表达上调，移植物间质中出现TNF-α的表达增加。结论单核细胞、NK细胞和T细胞介导的移植物损伤，在应用Y-CVF处理的猪-猕猴DXR发生中发挥重要作用。

Role of macrophages,NK cells,and T cells in delayed xenograft rejection of pig-to-rhesus monkey cardiac transplantations after a high activity Y-CVF therapy

Objective To investigate the role of macrophages,NK cells,and T cells in delayed xenograft rejection of pig-to-rhesus monkey cardiac transplantations.Methods Heterotopic xenogeneic heart transplantation in the abdominal cavity was performed using piglet as donors.The experiment was devided into 2 groups:control group (n=5):without a high activity cobra venom factor (Y-CVF) treatment;experimental group (n=4):complete complement depletion was achieved in the recipients treated with Y-CVF.The recipients were immunosuppressed with a combination of cyclosporine A,cyclophosphamide and steroids.The graft were examined histopathologically and immunohistochemically for necrosis factor-alpha (TNF-alpha),intercellular adhesion molecule-1 (ICAM-1),CD 57 (NK cells),CD 68 (macrophages),CD 4 and CD 8.Results The survival time of 3 xenografts in control group was 15 to 60 min and hyperacute rejection (HAR) occurred,while the remaining 2 xenografts survived 22 h and 6 days respectively,and there was no significant cellular infiltration and the expression of ICAM-1 and TNF-alpha in HAR xenografts.But in the experimental group,the xenografts survived 8,10,13,13 days respectively and DXR occurred in all the grafts.Large numbers of macrophages (50%) were found to infiltrate the entire xenograft.8% to 10% of natural killer cells,15% of CD 4 T cells and 25% CD 8 T cells were detected also.ICAM-1 was up-regulated in the graft endothelial cells and TNF- alpha in the interstitial tissue was demonstrated in the rejected heart.Conclusion Cell-mediated rejection is an important feature in the DXR of pig-to-rhesus monkey cardiac transplantations after Y-CVF therapy.