猪-猕猴延迟性异种移植排斥反应的发生机制

Pathogenesis of delayed xenograft rejection in pig-to-rhesus monkey cardiac transplantations

目的 :探讨猪 猕猴延迟性异种移植排斥反应 (DXR)的发生机制。方法 :建立湖北白猪 云南猕猴的腹腔异位心脏移植模型 ,应用中华眼镜蛇毒因子 (Y CVF)完全清除受者体内补体 ,并应用环孢素A(CsA)、环磷酰胺 (CTX)和甲泼尼龙 (M .P)三联免疫抑制治疗。检测血清C3、C4、抗猪内皮细胞天然抗体 ,免疫组化方法染色检测移植物中C3、C5b 9、IgG、IgM、细胞间黏附分子 1(ICAM 1)、肿瘤坏死因子 α(TNF α)、单核巨噬细胞 (CD6 8)、NK细胞 (CD5 7)、CD4 +T细胞和CD8+T细胞的表达。结果 :移植心存活时间分别为 8、10、13和 13天 ,血清C3和补体总活性均下降为 0 ,抗猪内皮细胞天然抗体水平在移植后则有一个更为明显的下降 ,在移植心失功前 2～ 4天开始天然抗体稍有回升 ,但较术前正常时仍明显偏低。移植心有程度不等的C3、C4、C5b 9、IgG及IgM沉积 ,大量的单核细胞 (5 0 % ) ,少量的NK细胞 (8%～ 10 % )、CD4 +T细胞 (15 % )和CD8+T细胞(2 5 % )。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 :体液免疫和细胞免疫参与猪 猕猴DXR排斥反应的发生。

Objective:To investigate the pahtogengesis and pathology of delayed xenograft rejection (DXR) after pig to rhesus monkey heart xenotransplantation.Methods:Heterotopic xenogeneic heart transplantation in the abdominal cavity was performed using piglet as donors.4 monkeys were used as recipients.Complete complement depletion was achieve in the recipients treated with repetitive doses of a high activity cobra venom factor (Y CVF).The recipients were immunosuppressed with a combination of cyclosporine A,cyclophosphamide and steroids.Sera were analyzed for C3,C4 levels and complement activity and anti pig endotheliocyte xenoantibody.The graft were examined histopathologically and immunohistochemically for C3,C4,C5b 9,IgM,IgG,necrosis factor alpha (TNF alpha),intercellular adhesion molecule 1 (ICAM 1),CD57 (NK cells),CD68 (macrophages),CD4 and CD8.Results:The xenografts survived 8,10,13,13 days respectively and all grafts occoured DXR.Venular thrombosis was outstanding feature within DXR xenografts,complicated with interstitial edma,local hemorrhage and myocardial necrosis,with mild to moderate cellular infiltration.The serum C3 levels and complement activity almost decreased to 0 from the day of transplantation due to Y CVF,the C4 level began to decrease 2 4 days before the cardic xenografts losing their function.The anti pig endotheliocyte xenoantibody also decreased after transplantation,and slightly increased during DXR,all rejected xenografts showed C3,C4,C5b 9,IgG and IgM deposits in different degree.Large numbers of macrophages (50% of total leukocytes) were found infiltrating the entire xenograft,a few natural killer cells (8%～10%),some of CD4+T cells (15%) and CD8+T cells (25%) were detcted also,up regulation of ICAM 1 on the graft endothelial cells and TNF alpha in the interstitial were demonstrated in the rejected heart.Conclusion:Both Humor and cell mediated immunologic reaction may play an important role in pahtogengesis of DXR. [