类风湿关节炎患者外周血和滑液中CD4~+CD25~+调节性T细胞的水平变化

了解具有抑制功能的CD4+CD25+调节性T细胞(Treg)在类风湿关节炎(RA)中的水平变化。分离32例RA患者及35例正常对照者外周血和15例RA关节滑液中的单个核细胞,用荧光抗体标记细胞膜表面CD4、CD25分子和细胞内Foxp3转录因子,进行流式细胞分析,同时用RT-PCR方法测定单个核细胞中Foxp3 mRNA水平。实验发现RA外周血中CD4+CD25hT细胞比例(1.90±1.68)与健康人(1.81±1.79)无明显差异,而RA关节滑液中CD4+CD25+和CD4+CD25hT细胞含量却明显增高(14.98±12.52,8.94±9.67,P<0.01)。RA患者外周血单个核细胞中Foxp3+/CD4+T细胞比值(2.35±2.06)较正常人(7.25±3.98)明显降低(P<0.01),RA外周血中Foxp3 mRNA含量较正常人Treg减少,而RA关节液中Foxp3 mRNA含量较RA外周血更为低下(P<0.01)。RA患者存在CD4+CD25+Treg的异常改变,其外周血和关节液中具有抑制作用的Treg含量明显降低提示RA患者Treg数量减少及抑制功能下降可能是RA自身免疫反应亢强不能控制的原因之一。RA关节液中CD4+CD25hT细胞增高考虑与RA炎症反应造成T细胞过度活化有关。

Changes of CD4+CD25+ regulatory T cell level in peripheral blood and synovial fluid of patients with rheumatoid arthritis

To observe the changes of CD4+CD25+ regulatory T cells(Treg) with suppressive function in peripheral blood and synovial fluid of patients with rheumatoid arthritis(RA),the mononucleated cells from peripheral blood of 32 RA patients and 35 normal individuals and from synovial fluids of 15 RA patients were isolated and they were labeled with fluorescence antibodies for CD4,CD25 and Foxp3 molecules.The stained cells were then analyzed with flow cytometry.Meanwhile,RT-PCR assay was used to detect the expression level of Foxp3 mRNA in mononucleated cells.The laboratory data thus obtained were analyzed in combination with clinical index.The laboratory findings showed that no significant difference existed on percentage of the CD4+CD25high cells in peripheral blood between RA patients and normal controls(1.90±1.68 vs 1.81±1.79),whereas enhanced CD4+CD25+ and CD4+CD25high populations in synovial fluids of RA patients were noticed(14.98±12.52;8.94±9.67,P<0.01).The percentage of Foxp3+/CD4+ T cells in peripheral blood of RA patients(2.35±2.06) was significantly reduced in comparison with those of controls(7.25±3.98,P<0.01).Although the expression of Foxp3 mRNA in peripheral blood of RA patients was decreased,it was even much lower in synovial fluids of RA patients(P<0.01).It is evident that abnormality in the CD4+CD25+ regulatory T cells is actually present in patients with RA,expressed as the decreased amount of Tregs with suppressive effect in peripheral blood and synovial fluids and the reduced Tregs function.It may be one of the cause of inability to control the elevation of the autoimmune reaction in RA.