妊娠诱导的调节性T细胞对naïve T细胞抑制作用的体外研究

摘要

目的研究调节性T细胞（ Treg）及妊娠诱导的调节性T细胞（ piTreg）对naïve T细胞增殖的体外抑制，评价其抑制率的差异。方法对孕12．5 d（E12．5d）异基因交配孕鼠C57/B6（♀）× BALB/c（♂）的piTreg和未孕雌鼠C57/B6鼠的 Treg 进行流式细胞术检测，观察piTreg 和Treg 在CD4＋T细胞中比例及其胞内Foxp3表达变化；采用羧基荧光素二醋酸盐琥珀酰亚胺酯（ CFSE ）标记的naïve T作为效应细胞和丝裂霉素C灭活的CD4-T细胞作为刺激细胞的单向混合淋巴细胞培养体系，比较piTreg和Treg对效应细胞的体外抑制强度。结果 piTreg水平明显高于Treg（P＜0．001），且这些细胞均表达高水平的Foxp3；piTreg 在体外实验中对naïve T细胞的抑制效应明显高于Treg （ P＜0．006），并受其细胞数量的影响。结论妊娠诱导的调节性T细胞较来自于非孕鼠的Treg对naïve T细胞有更明显的抑制作用，这一现象很可能是由妊娠中父系抗原刺激诱导的CD4＋CD25＋Treg活性差异造成。%Objective To investigate the in vitro inhibitory effects of regulatory T cells ( Treg ) from unpregnant mice and pregnancy-induced regulatory T cells ( piTreg) on the proliferation of naïve T cells and their differences .Methods The numbers of piTreg cells from allogeneic pregnant mice ( C57/B6 fe-male×BALB/c male) on day 12.5 (E12.5d) of gestation and Treg cells from unpregnant C57/B6 mice were detected respectively by flow cytometry .The percentages of piTreg cells and Treg cells in CD 4+T cells of age-matched female mice and their intracellular expression of Foxp 3 were analyzed .The in vitro inhibitory effects of piTreg cells and Treg cells on the CFSE-labeled naïve T cells ( effector cells ) were compared in a one-way mixed lymphocyte culture system using mitomycin C-inactivated CD4-T cells as stimulator cells . Results The level of piTreg cells in splenic mononuclear cells was significantly higher than that of Treg cells (P<0.001) from normal mice.Foxp3 was highly expressed in both piTreg cells and Treg cells , howev-er slightly increased in piTreg cells .Moreover , piTreg cells had a significant stronger in vitro inhibitory effect on naïve T cells proliferation than that of Tregs cells (P<0.006), which was in a cell-dependent manner. Conclusion The present study suggests that the piTreg cells have a stronger inhibitory effect on na ïve T cell proliferation as compared with Terg cells from unpregnant mice , The differential activity of CD 4+CD25+Treg might be mediated by the paternal antigens during pregnancy .