CD4^+CD25^+Foxp3^+调节性T细胞对ox-LDL诱导内皮细胞炎性因子表达的影响

CD4^+CD25^+Foxp3^+ regulatory T cells modulate inflammatory cytokines expression mediated by oxidized low density lipoprotein in human umbilical vein endothelial cells

目的:探讨CD4+CD25+调节性T细胞(Tregs)对氧化型低密度脂蛋白(ox-LDL)诱导人脐静脉内皮细胞(HUVECs)炎性因子表达的影响。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,将HUVECs分别与anti-CD3mAb激活的CD4+CD25+T细胞、CD4+CD25-T细胞共培养24h。分别应用流式细胞术、ELISA、real-timePCR测定Tregs对ox-LDL诱导损伤HUVECs炎性因子VCAM-1、MCP-1、IL-6表达的影响。应用凝胶电泳迁移率实验(EMSA)方法观察Tregs对ox-LDL诱导损伤HUVECsNF-κB激活的影响。结果:与对照组比较,Tregs细胞可显著抑制ox-LDL诱导损伤HUVECs炎性因子(VCAM-1、MCP-1、IL-6)及NF-κB的结合活性。结论:Tregs细胞可显著抑制ox-LDL诱导损伤HUVECs炎性因子的表达,其作用机制可能为下调了NF-κB的结合活性。

Objective：To investigate the effects of CD4＋CD25＋Foxp3＋ regulatory T cells （Tregs） on inflammatory cytokines expression mediated by oxidized low-density lipoprotein （ox-LDL）-in human umbilical vein endothelial cells （HUVECs）.Method：HUVECs were incubated alone （noT）,with Tregs （CD25＋）,or CD4＋CD25-T cells （CD25-） in the presence of anti-CD3 mAbs for 48h,then were stimulated with ox-LDL for an additional 24h.Flow cytometry and ELISA were used to measure the expression of inflammatory cytokines like vascular cell adhesion molecule-1 （VCAM-1）,monocyte chemoattractant protein-1 （MCP-1） and interleukin-6 （IL-6） in HUVECs response to ox-LDL,respectively.EMSA were carried out to determine the activation of NF-κB in HUVECs impaired by ox-LDL.Result：The protein levels of inflammatory cytokines expression in HUVECs were determined by Flow cytometry or ELISA,which showed a significant reduction of inflammatory cytokines （VCAM-1：13.5±4.0%;MCP-1：16.6± 2.0 ng/ml;IL-6：1.9±0.8 ng /ml） in CD25＋ system compared with that in noT system （VCAM-1：57.6±5.2%;MCP-1：42.4±5.8 ng/ml;IL-6：8.8±1.4 ng/ml） or CD25-system （VCAM-1：58.1±7.1%;MCP-1：46.7±4.0 ng/ml;IL-6：9.3±1.7 ng/ml）.The similar effects of Tregs on the mRNA levels of inflammatory cytokines expression in HUVECs were obtained.Moreover,this study reveal that Tregs-mediated suppression of the HUVECs response to ox-LDL was reflected by a reduction in the up-regulation of NF-κB activity.Conclusion：Tregs inhibits the inflammatory cytokines like VCAM-1,MCP-1 or IL-6 response of HUVECs to ox-LDL by reducing the up-regulation of NF-κB activation.