CD4^+CD25^+调节性T细胞对内皮细胞抗原提呈功能的影响及机制

CD4^+CD25^+ regulatory T cells modulate antigen-presenting function of human umbilical vein endothelial cells

目的:探讨CD4+CD25+调节性T细胞(Treg)对内皮细胞抗原提呈功能的影响及机制。方法:磁性细胞分离器(MACS)分离CD4+CD25+T细胞及CD4+CD25-T细胞。在ox-LDL作用下,HUVECs与CD4+CD25+T细胞共培养,24小时后收集HUVECs。应用流式细胞术测定HUVECs抗原提呈分子(HLA DR,CD86,CD80)的表达,Cell Counting Kit-8法(CCK-8)测定HU-VECs刺激CD4+CD25-T细胞增殖的能力,Transwell小室实验初步探讨Treg作用于HUVECs的具体机制。结果:与对照组比较,Treg可显著抑制HUVECs抗原提呈分子的表达及刺激T细胞增殖的能力。用Transwell隔离后,与or-LDL刺激组比较,HU-VECs抗原提呈分子表达及其刺激T细胞增殖的能力无明显变化。结论:Treg可显著抑制HUVECs抗原提呈能力,其作用机制可能为下调CD86的表达,且依赖细胞直接接触。

Objective：To investigate whether and how Treg affect the antigen-presenting function of HUVECs,and the mechanism of Treg in the development of atherosclerosis.Methods：Treg were isolated from human peripheral blood mononuclear cells（PBMCs） which obtained from normal volunteers by magnetic cell sorting-column and analyzed by Flow Cytometry.HUVECs were incubated alone（control） or with anti-CD3 mAbs activated Treg（CD25＋） and ox-LDL.After 24 h,HUVECs were collected and the expression of HLA DR,CD80 and CD86 were measured by flow cytometry.ox-LDL treated HUVECs which were pre-cultured with different concentrations of human anti-CD3 mAbs activated Treg were used to stimulate CD4＋CD25-T cells,and then the effect of HUVECs on the proliferation of CD4＋CD25-T cells were detected by Cell Counting Kit-8（CCK-8）.Transwell experiment was used to identify how Treg affect the antigen-presenting function of HUVECs.Results：Treg can significantly inhibit the expression of antigen presenting molecular in HUVECs as well as the effect of HUVECs on the proliferation of CD4＋CD25-T cells when compared with that in control system;Mechanistic studies reveal that the expression of antigen presenting molecular in HUVECs and the effect of HUVCs on the proliferation of CD4＋CD25-T cells in TW system have no difference when compared with that in no T system.Conclusion：Treg are able to modulate the antigen-presenting function of HUVECs,which is largely attributed to a down-regulated expression in CD86 in Treg-treated HUVECs and depended on cell contact.