抑制性T淋巴细胞在大鼠同种心脏移植免疫耐受中的作用

目的　探讨抑制性T淋巴细胞在同种心脏移植免疫耐受中的作用。方法　将纯系DA(供体 )、纯系Lewis大鼠 (受体 )各 5 0只随机分为未处理组、脾细胞组、环磷酰胺组、脾细胞 环磷酰胺组、转移组 ,每组受、供体鼠各 10只 ,各组受体鼠分别采用不处理、门静脉注入供体脾细胞 ( 3× 10 8个 )、腹腔注入环磷酰胺 ( 80mg/kg)、供体脾细胞 环磷酰胺、脾细胞 环磷酰胺组心脏移植术后30d受体大鼠脾细胞进行免疫耐受诱导后行腹部心脏移植 ;观察各组供心存活时间、病理改变及供受体间的混合淋巴细胞反应 (MLR)。结果　脾细胞 环磷酰胺组产生了长期的免疫耐受 ,供心平均存活时间为 ( 71 5± 2 9 1)d ,较未处理组、脾细胞组、环磷酰胺组均显著延长 (t=- 14 0 6 3,- 13 915 ,- 13 777,均P <0 0 1) ,供心仅有少量炎性细胞浸润 ,供受体间MLR特异性降低 (t =2 9 90 2 ,P <0 0 1)。转移组供心平均存活时间为 ( 5 2 3± 7 5 )d ,供心仅有少量炎性细胞浸润 ,供受体间MLR特异性降低 (t=2 3 0 4 7,P <0 0 1)。结论　脾细胞 环磷酰胺可成功诱导同种大鼠心脏移植的免疫耐受 ,其免疫耐受状态可过继转移给正常的同系受体 ,抑制性T淋巴细胞在这种免疫耐受状态中起重要作用

Effect of T suppressor cells on the maintenance phase of tolerance to cardiac allografts in the rats

OBJECTIVE: To study the role of T suppressor cells in immune tolerance to cardiac allografts in the rats. METHODS: Male DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into five groups: group 1: untreated, group 2: portal venous injection of 3 x 10(8) DA splenocytes to Lewis rat, group 3: intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, group 4: portal venous injection of 3 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, 15 days later heart transplantation was performed. Group 5: intravenous injection 3 (108 splenocytes of group 4 to normal recipient, and then heart transplantation was performed. Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR) were measured after operation. RESULTS: The survival time of heart allografts in the group 4 [MST: (71.5 +/- 29.1) d, t = -14.063, -13.915, -13.777; P < 0.01] was significantly longer than in the groups of 1 [MST: (7.3 +/- 1.0) d], 2 [MST: (7.8 +/- 0.8) d], 3 [MST: (8.2 +/- 1.1) d ]. Only a few inflammatory cells infiltrated in cardiac allografts in the groups of 4 and 5. MLR in the groups of 4 and 5 were significantly decreased compared with those of normal control (t = 29.902, 23.047; P < 0.01). CONCLUSIONS: Portal venous injection of donor splenocytes combined with intraperitoneal injection of cyclophosphamide could induce immune tolerance to cardiac allografts. The immune tolerance could be transferred through splenocytes. T suppressor cells play an important role in the immune tolerance.