目前器官移植中常面临的一个问题是身体会“认生”，即免疫系统会对移植器官产生排异反应。英国研究人员报告说找到了一种让免疫系统和移植器官提前变成“熟人”的办法，能减少器官移植中的排异反应。
英国牛津大学等机构的研究人员在美国新一期《科学—转化医学》（Science Translational Medicine）上报告说，在这个过程中起关键作用的是一种名为调节性T细胞的免疫细胞。这种细胞具有降低免疫反应的功能。领导研究的安德鲁·布谢尔介绍说，免疫系统就像是一支与病毒等外来入侵者作战的军队，但当战争结束后，总要有人来告诉士兵们停止开火，对免疫系统而言调节性T细胞就起着这样的作用。
因此，研究人员想到可以让调节性T细胞提前“认识”将要移植的器官，这样它就可以通知免疫系统不再发动攻击。研究人员对实验鼠进行了血管移植，并提前从要移植的血管中提取出一些细胞，将它们和一些调节性T细胞在特定条件下共同培养，在这些细胞彼此“熟悉”后，再将调节性T细胞注入进行血管移植的实验鼠体内，果然成功减少了排异反应。
布谢尔说，现在一些不同的研究小组正在探索培养调节性T细胞的不同方式，今后相关领域中的一个关注点将是比较哪种方式最有效，能最大程度减少器官移植中的排异反应。（生物谷Bioon.com）
生物谷推荐原文：
Science Translational Medicine DOI： 10.1126/scitranslmed.3002099
Functional Regulatory T Cells Produced by Inhibiting Cyclic Nucleotide Phosphodiesterase Type 3 Prevent Allograft Rejection
Feng, Gang; Nadig, Satish N.; B?ckdahl, Liselotte; Beck, Stephan; Francis, Ross S.; Schiopu, Alexandru; Whatcott, Andrew; Wood, Kathryn J.; Bushell, Andrew
Regulatory T cells (Tregs) manipulated ex vivo have potential as cellular therapeutics in autoimmunity and transplantation. Although it is possibleto expand naturally occurring Tregs, an attractive alternative possibility, particularly suited to solid organ and bone marrow transplantation, is the stimulationof total T cell populations with defined allogeneic antigen-presenting cells (APCs) under conditions that lead to the generationor expansion of donor-reactive, adaptive Tregs. Here we demonstrate that stimulation of mouse CD4+ T cells by immature allogeneic dendritic cells combined with pharmacological inhibition of phosphodiesterase 3 (PDE) resultedin a functional enrichment of Foxp3+ T cells. Without further manipulation or selection, the resultant population delayed skin allograft rejection mediated bypolyclonal CD4+ effectors or donor-reactive CD8+ T cell receptor transgenic T cells and inhibited both effector cell proliferation and T cell priming for interferon-γ production.Notably, PDE inhibition also enhanced the enrichment of human Foxp3+ CD4+ T cells driven by allogeneic APCs. These cells inhibited T cell proliferation in a standard in vitro mixed lymphocyte assayand, moreover, attenuated the development of vasculopathy mediated by autologous peripheral blood mononuclear cells in a functionallyrelevant humanized mouse transplant model. These data establish a method for the ex vivo generation of graft-reactive, functionalmouse and human Tregs that uses a clinically approved agent, making pharmacological PDE inhibition a potential strategy for Treg-based therapies.
