成人微小病变肾病患者外周血CD4~＋Foxp3~＋调节性T细胞的研究

目的研究CD4＋Foxp3＋调节性T细胞（CD4＋Foxp3＋Treg）及亚群在成人微小病变肾病（MCD）患者外周血CD4＋T细胞中的分布,探讨CD4＋Foxp3＋Treg参与MCD发病的可能机制。方法以27例经肾穿刺活检确诊为MCD的初发成人患者作为研究对象,采用Foxp3-FITC/CD45RA-PE/CD3-ECD/CD4-PC7抗体组合经流式细胞仪检测外周血单个核细胞（PBMCs）中CD4＋Foxp3＋Treg及亚群占CD4＋T细胞的百分比。Real-Time PCR检测PBMCs中Foxp3、Th17转录因子RORc以及细胞因子TGF-β1、IL-6、IL-17A、IL-23mRNA表达。设立正常对照。结果流式细胞检测显示CD4＋Foxp3＋Treg分成3个细胞群体,分别为CD45RA＋Foxp3low（Ⅰ区,静息期Treg）、CD45RA-Foxp3high（Ⅱ区,活化Treg）和CD45RA-Foxp3low（Ⅲ区）。MCD组Ⅰ区＋Ⅱ区细胞和Ⅱ区细胞占CD4＋T细胞的百分比显著低于对照组（P〈0.01）。MCD组PBMCs中Foxp3mRNA表达较对照组下调（P〈0.05）,RORcmRNA表达较对照组上调（P〈0.05）,IL-6、IL-17A、IL-23mRNA表达均显著高于对照组（P〈0.05和P〈0.01）。相关性分析显示,MCD组IL-17A mRNA表达与Ⅱ区细胞占CD4＋T细胞的百分比呈显著负相关（r=-0.81,P〈0.05）。结论成人MCD患者外周血Treg及其活化功能亚群减少,同时伴有Th17转录基因及其相关细胞因子表达的异常升高。提示Treg Foxp3 mRNA表达下调及Treg/Th17细胞比例失衡可能与MCD的发病有关。

Study of CD4+Foxp3+ regulatory T cells in peripheral blood of adult minimal change disease

Objective To observe the distribution of CD4+Foxp3+ regulatory T cells (CD4+Foxp3+ Treg) and the subsets in CD4+T cells in peripheral blood of adults with minimal change disease (MCD), and explore the significance of CD4+Foxp3+Treg in the pathogenesis of MCD. Methods Twenty-seven adults with MCD initially diagnosed by renal biopsy were selected. The antibody combination of Foxp3-FITC/CD45RA-PE/CD3-ECD/CD4-PC7 was adopted and flow cytometry was employed to determine the percentage of CD4+Foxp3+ Treg and the subsets in CD4+T cells in peripheral mononuclear cells (PBMCs). The expression of Foxp3, RORc, TGF-β1, IL-6, IL-17A and IL-23 mRNA in PBMCs was detected by Real-Time PCR. Besides, normal controls were established. Results Flow cytometry revealed that CD4+Foxp3+Treg were divided into three subsets: CD45RA+Foxp3lowcells(Fr.Ⅰ, resting Treg), CD45RA-Foxp3highcells (Fr.Ⅱ, active Treg) and CD45RA-Foxp3lowcells (Fr.Ⅲ). The percentages of cells of Fr.Ⅰ+Fr.Ⅱ and cells of Fr.Ⅱ in CD4+ T cells in MCD group were significantly lower than those in control group (P<0.01). The expression of Foxp3 mRNA in PBMCs in MCD group was significantly lower than that in control group （P<0.05）, while the expression of RORc mRNA in PBMCs in MCD group was significantly higher than that in control group （P<0.05）, and the expression of IL-6, IL-17A and IL-23 mRNA was significantly higher than that in control group （P<0.05, P<0.01）. Correlation analysis revealed that the expression of IL-17A mRNA was negatively related to the percentage of cells of Fr.II in CD4+T cells in MCD group （r=-0.81，P<0.05）. Conclusion In adults with MCD, there is decreased expression of Treg and active Treg subsets and increased expression of Th17-related gene and cytokines in peripheral blood, which suggests that the down-regulated expression of Treg Foxp3 mRNA and Treg/Th17 imbalance might be involved in the pathogenesis of MCD.