溃疡性结肠炎患者外周血Th17／Treg免疫平衡的研究

Study on the balance of the peripheral blood Th17/Treg cells in patients with ulcerative colitis

目的研究溃疡性结肠炎（UC）患者外周血Th17细胞（CD4＋IL-17＋T细胞）与Treg细胞（CD4^＋CD25^＋T细胞）数量以及相关细胞因子的表达水平，分析Th17／Treg细胞免疫平衡在UC发病机制中的作用。方法收集UC患者（UC组）和健康体检者（对照组）的外周肝素抗凝静脉血，分离纯化T淋巴细胞。分别以PE-CD4与FTTC—CD25单抗，PE-CD4与FITC—IL-17的单抗作双色流式细胞术，分析溃疡性结肠炎患者外周血Th17、Treg细胞的百分率，ELISA法检测血清中相关细胞因子IL-17和TGF—β1的水平。结果与对照组比较，溃疡性结肠炎患者外周血Th17细胞百分率升高，Treg细胞的百分率显著下降，Th17／Treg比值升高（P〈0．05），血清中细胞因子IL-17升高、TGF-β1降低，并且IL-17／TGF-β1比值升高。结论溃疡性结肠炎患者外周血存在细胞免疫功能失调；Th17／Treg细胞数量与免疫平衡状态发生改变，T淋巴细胞耐受机制的破坏可能与溃疡性结肠炎的发病机制有关。

Objective To investigate the quantity of peripheral blood CD4^＋ IL-17 ＋ T（Th17）and CD4^＋ CD25^＋ regulatory T cell（Treg ）, and the expression of related cytokines in ulcerative colitis （ UC ） patients, and to analyze the role of Th17/Treg balance in the pathogenesis of UC. Methods Anti-coagulated venous blood by heparin was collected from UC patients and healthy people. T cells were collected by Human CD3 T cell Enrichment Column. The quantity of peripheral blood Th17 and Treg was detected by immunofluorescence staining and bicolor flow cytometry. The levels of related eytokines IL-17, TGF-β1 were assayed by ELISA methods. Results Compared with healthy people,in UC patients,the expression of Th17 cell and the level of related cytokine IL-17 both were increased significantly（P 〈0.05 ） ,but the amount of Treg cell and the level of related cytokine TGF-β1 were decreased（P 〈0.05） ,the ratios of Th17/Treg and IL-17/TGF-β1 both were increased. Conclusion There is peripheral blood cellular immunological function disorder in UC patients,and the abnormal ratio of Th17/Treg cell and the related cytokines IL-17/TGF-β1 may involve in UC immunopathogenesis.