多次输注供体脾细胞诱导心脏移植免疫耐受的实验研究

Induced tolerance to cardiac allograts with multiple intravenous injection of donor spleen cells

目的 探讨供体脾细胞诱导心脏移植免疫耐受的作用。方法 将 5 0只行腹部心脏移植的纯系雄性Lewis大鼠 ,随机分为未处理组、一次脾细胞组、环磷酰胺组、一次脾细胞 +环磷酰胺组、多次脾细胞 +环磷酰胺组 ,每组 10只大鼠 ,以 5 0只纯系雄性DA大鼠为供体。观察移植心脏平均存活时间 (MST) ,移植后第 6天观察供体心脏病理学改变 ,供受体间的混合淋巴细胞反应 (MLR)、外源性白细胞介素 2 (IL 2 )对MLR的影响及体外过继转移实验。结果 多次脾细胞 +环磷酰胺组供体心脏MST为 (85 3± 7 5 )d ,较未处理组 (7 3± 1 0 )d、一次脾细胞组 (7 9± 0 9)d、环磷酰胺组(8 1± 1 2 )d、一次脾细胞 +环磷酰胺组 (2 5 8± 3 5 )d显著延长 (t=0 ,P <0 0 1) ;供体心脏仅见少量炎性细胞浸润 ;供受体间MLR较DA Lewis对照组显著降低 ,差异有显著意义 (P <0 0 1) ;外源性IL 2可以部分逆转DA Lewis耐受组MLR的低反应性 ;其免疫耐受状态可过继转移给正常的同系大鼠。结论 多次输注供体脾细胞联合应用环磷酰胺 ,可成功诱导同种大鼠心脏移植的免疫耐受。

Objective To study the methods and mechanisms of immune tolerance in cardiac transplantation. Methods Male DA rat hearts were transplanted to male Lewis rats using Ono′s model and randomly divided into five groups: untreated, intravenous injection of 1×10 8 DA splenocytes to Lewis rat, intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat, intravenous injection of 1×10 8 DA splenocytes combined with intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat, multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide, 11 days later heart transplatation was performed. Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR), the role of interleukin 2 (IL 2) to MLR and the role of tolerant rat splenocytes to MLR were measured after operation. Results The survival time of heart allografts in the group of multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide [MST:(85 3±7 5) d, t =0, P <0 01] was significantly longer than in the groups of untreated [MST:(7 3±1 0) d], intravenous injection of 1×10 8 DA splenocytes to Lewis rat [MST:(7 9±0 9) d], intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat [MST:(8 1±1 2) d], intravenous injection of 1×10 8 DA splenocytes combined with intraperitoneal injection of cyclophosphamide (100 mg/kg) to Lewis rat [MST:(25 8±3 5) d]. Only a few inflammatory cells infiltrated in cardiac allografts in the group of multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide. MLR in the group of multiple injection of DA rat splenocytes with intraperitoneal injection of cyclophosphamide were significantly decreased compared with those of normal control ( t =0, P <0 01). IL 2 could partly reversed the hyporesponsiveness of MLR in tolerant rats, the tolerance could be transferred in vitro. Conclusions Multiple injection of donor splenocytes combined with intraperitoneal injection of cyclophosphamide to recipients could induce immune tolerance to cardiac allografts.