供体脾细胞输注诱导小鼠移植耐受及其机理的研究

Study on the induction of transplantation tolerance in mice by continuous infusion of donor spleen cells and its mechanisms

目的 以持续供体脾细胞输注的方法建立异基因嵌合体动物模型 ,并探讨移植耐受形成的机制。方法 BALB c(H 2 d)小鼠经尾静脉注入C5 7BL 6 (H 2 b,B6 )脾细胞 5× 10 7,2d后 ,给BALB c小鼠腹腔注射环磷酰胺 (Cy) 15 0mg kg体重 ,注射Cy后 1d ,开始给BALB c小鼠静脉注射B6源小鼠的脾细胞 1次 d ,10 7 次 ,共持续 5d。之后 ,通过皮肤移植、混合淋巴细胞反应 (MLR)确定移植耐受的状态 ,并通过过继转移实验、嵌合体检查及耐受和排斥小鼠脾细胞中细胞因子mRNA的表达情况 ,进一步探讨耐受形成的机制。结果 耐受小鼠获得供体特异性移植耐受 ;耐受可以被过继转移 ;耐受小鼠体内嵌合程度与耐受程度有一定相关性 ;IL 2、IFN γ等TH1型细胞因子在耐受小鼠脾细胞中较对照小鼠明显降低 ,IL 10在耐受小鼠中的表达明显升高 ,但IL 4在耐受小鼠中的表达与排斥小鼠差异无显著性。结论 供体脾细胞 +Cy +持续供体脾细胞输注可以诱导供体特异性耐受 ;多种耐受机理 ,包括嵌合体形成、抑制细胞以及TH1 TH2型细胞的偏移都对耐受形成起作用。

Objective To study the mechanisms of tolerance induced by continuous infusion of donor derived cells to recipient mice. Methods BALB/c (H 2 d) mice received an injection of allogeneic spleen cells via the tail vein from C57BL/6 (H 2 b, B6) mice, followed by an intraperitoneal injection of cyclophosphamide (Cy) 2 days later. One day after the treatment of Cy, the mice were injected i.v . with B6 spleen cells for 5 days (one time/day, 10 7/time). Transplantation tolerance status of the recipient mice was tested by skin grafting and MLR. Adoptive transfer assay and analysis of cytokine mRNA expression in both tolerant and rejected mice were performed to further explore tolerance mechanisms. Results Skin graft tolerance of BALB/c mice to B6 mice was achieved and the levels of chimerism in thymus were related to the state of tolerance; The levels of IL 2 and IFN γ mRNA expression in tolerant BALB/c mice were much lower than those in the control mice, the levels of IL 10 mRNA in tolerant mice were much higher. Conclusions Treatment of mice with donor spleen cells plus Cy and continuous injection of donor spleen cells can induce a specific tolerance in BALB/c mice to B6 skin graft. Multiple mechanisms, including chimerism, suppressor cells, and deviation of T H1/T H2 cytokines were probably involved in the process.