移植免疫耐受中调节性B细胞与调节性T细胞的依赖性关系研究

目的 探讨在联合抗Tim-1/抗CD45RB抗体诱导的移植耐受中调节性B细胞(Bregs)与调节性T细胞(Tregs)的关系.方法 建立BALB/c小鼠到C57BL/6小鼠的同种胰岛移植长期耐受模型,将长期耐受小鼠(LTS)的B细胞过继输注至接受胰岛移植的B细胞缺陷小鼠(μMT-/-)体内,或加用抗CD25抗体(PC61)去除CD25+ Treg细胞,观察移植物的存活时间,用流式细胞仪检测Foxp3+ Treg数量变化.将CD4+ Foxp3-GFP-T细胞与Bregs细胞联合过继输注RAG小鼠体内,检测Foxp3+GFP+T细胞的扩增情况.建立小鼠皮肤移植模型,在双抗体治疗的同时加用抗CD20抗体祛除B细胞,观察对Tregs数量的影响.结果 继承性转移长期耐受小鼠的Bregs可诱导83.3％的小鼠长期耐受,但加用抗CD25单抗后,胰岛移植物在较短时间(MST=20 d)内全部被排斥;继承性转移长期耐受小鼠Bregs可使Tregs数量明显增加(P＜0.01),并且可诱导CD4+ Foxp-T细胞表达Foxp3;用抗CD20抗体祛除B细胞后,双抗体诱导的皮肤移植受体小鼠体内Tregs数量明显减少(P＜0.01).结论 在双抗体诱导的移植耐受中,Bregs可能通过促进Tregs生成而延长移植物的存活.

Dependence relationship between regulatory B cells and regulatory T cells in transplantation immune tolerance

Objective To investigate the relationship between regulatory B cells (Bregs) and regulatory T cells(Tregs) in transplantation tolerance induced by dual anti-CD45RB/anti-TIM-1 antibody.Methods The longterm murine islet allograft transplant models from BALB/c to C57BL/6 were established.B cells purified from longterm survivors (LTS)were adoptively transferred to grafted B cell-deficient μMT-/-B6 recipients and treated with or without PC61.The allograft survival time was analyzed and the number of Foxp3+ Treg cells was examined by flow cytometry.Murine skin allograft transplant models was established and treated with dual antibody.The change of the percentage of Treg cells was observed after B-cell depletion using anti-CD20 antibody.Results Adoptive transfer of Bregs in longterm tolerated murines could induce longterm tolerance in 83.3 ％ of murines.But after adding CD25m monoclonal antibody,islet grafts were completely rejected in a short time(MST=20 d);adoptive transfer of Bregs in longterm tolerated murines could increase the Tregs number(P＜0.01),moreover could induce CD4+ Foxp-T cell to express Foxp3;after deleting B cells with CD20 antobody,Tregs cells number in the skin transplant recipient murine induced by dual antibody was remarkably reduced (P＜0.01).Conclusion In transplantation tolerance induced by dual antibody,Breg cells may prolong the graft survival time possibly through promoting Treg generation.