未成熟树突状细胞联合骨髓移植诱导肾移植大鼠免疫耐受及其机制

Immune Tolerance Induced by Immature Dendritic Cells and Bone Marrow Transplantation in Rat Renal Allogeneic Graft Model and Its Mechanisms

目的 供体来源未成熟树突状细胞输注联合骨髓移植,诱导异体肾移植大鼠产生免疫耐受,并探讨其 机制。方法 肾移植大鼠分为5组:阴性对照组、未成熟树突状细胞组、骨髓移植组、联合诱导组、环磷酰胺组。 51Cr释放实验测定大鼠细胞毒性T淋巴细胞(CTL)细胞毒效应;ELISA检测脾细胞培养上清IL-4、IFN-γ、TGP- β水平。结果 阴性对照组肾移植大鼠的平均存活时间(MST)为(7.12±1.25)d,未成熟树突状细胞组为(24.38 ±3.20)d,骨髓移植组为(7.87±2.1)d,环磷酰胺组为(18.13±2.36)d,而联合诱导组延长到(80.75±16.88)d, 与上述4组比较,均存在显著性差异(P<0.01)。耐受组大鼠(CTL)杀伤率低于排斥组(4.3±1.0)υs(39.6± 4.4),(P<0.01)。耐受组大鼠脾细胞培养上清IL-4和TGF-β水平为(185.44±32.17)ng／L和(716.82± 197.62)ng／L,高于排斥组(P<0.01);而IFN-γ水平为(532.78±34.54)ng／L,低于排斥组(P<0.01)。结论 术前供体来源未成熟树突状细胞输注联合骨髓移植,可成功诱导受体大鼠产生免疫耐受,其机制可能与特异性 CTL无能及TH1／TH2/TH3细胞因子网络的免疫偏离有关。

Purpose To study immune tolerance induced by immature dendritic cells transfusion and bone marrow transplantation in rat renal transplantation model,and to explore a possible strategy for renal allograft protection in clinic. Methods Immature dendritic cells (imDC) and fresh bone marrow cells (BMC) from DA rat were prepared for use before transplantation. Renal allograft from DA rat was transplanted to Lewis rat. Forty recipient rats were randomly divided into 5 groups: (1) negative group; (2) imDC group; (3) BMT group; (4) imDC+ BMT group; (5) cyclophosphamide (CP) group. Anti-donor cytotoxic T lymphocyte activity was assayed by 51Cr release test. Cytokine in the supernatant of splenic cells culture were measured by ELISA,including IL-4,IFN-γ and TGF-β. Results The median survival time (MST) was (7.12±1.25) days in negative group,(24.36±3.20) days in imDC group, (7.87±2.10) days in BMT group,(18.13±2.16) days in Cp group. When combined imDC transfusion and BMT,the MST was prolonged to (80.75±16.88) days, which had significant difference compared with negative group, imDC group,BMT group and CP group (P<0.01).CTL from tolerant rats had decreased cytotoxicity to cells from donor rats (4.3±1.0)% vs (39.6±4.4)%,P<0.01),but showed normal cytotoxicity to cell from the third party rat (9.8±3.2) %.IFN-γ in the supernatant of tolerant rat splenic cells culture was (532.78±34.54) ng/L,which was lower than normal and rejection rat (P<0.01). IL-4 and TGF-β in the supernatant of tolerant rat splenic cells culture was (185.44±32.17) ng/L and (716.82±197.62) ng/L, which was higher than normal or rejection rat (P<0. 01). Conclusions Combined used of imDC transfusion and bone marrow transplantation is an effective way to induce immune tolerance in rat renal transplantation model. Its possible mechanisms may due to immune deviation of cytokine net and rat donor-specific CTL anergy.