地塞米松对系统性红斑狼疮患者外周血单个核细胞中细胞因子分泌及T细胞亚群表达的影响

Effects of dexamethasone on the secretion of cytokines and the expression of T cell subsets in peripheral blood mononuclear cells of patients with systemic lupus erythematosus

目的 探讨地塞米松对系统性红斑狼疮（SLE）患者外周血单个核细胞（PBMCs）中白细胞介素（IL）-17、干扰素（IFN）-γ分泌水平和Th17、Tc17、Th1、Tc1等T细胞亚群表达的影响.方法 SLE患者和健康对照者的PBMCs分空白孔、佛波酯（PMA）/离子霉素（Ionomycin）孔、PMA/Ionomycin＋地塞米松（DEX）孔行体外培养,运用四色流式细胞术检测PBMCs表达Th17、Tc17、Th1、Tc1等T细胞亚群的百分比,采用酶联免疫吸附法测定SLE患者和健康对照者血浆及PBMCs培养上清中IL-17、IFN-γ的表达水平.结果 SLE组患者血浆IL-17[138.98（84.82～187.04）ng/L]、IFN-γ[21.92（15.95～27.09）ng/L]含量均高于正常对照组[57.21（47.78～72.12）ng/L,13.43（7.04～17.37）ng/L].无PMA刺激条件下,SLE患者PBMCs培养上清中细胞因子水平、PBMCs中各T细胞亚群的百分比与正常对照组相比差异均无统计学意义（P均＞0.05）;加入PMA刺激后,SLE患者PBMCs上清中IL-17的水平[（26.43±10.04）ng/L]和外周血Th17[（2.49±1.49）%]、Tc1[（44.89±16.43）%]细胞的比例均显著高于正常对照组[（18.06±5.42）ng/L,（1.47±0.73）%,（31.41±9.05）%）（P均＜0.05）,SLE患者Th1、Tc17细胞百分比与正常对照组相比,差异均无统计学意义（P均＞0.05）;地塞米松能明显抑制活化状态下的PBMCs分泌IL-17的水平[（16.72±6.09）ng/L]（P＜0.01）,且显著下调Th17（1. 34±0.76）%、Tc1（34.62±17.25）%细胞百分比（P均＜0.05）,而地塞米松对IL-17的抑制作用更强.结论 SLE患者体内T细胞亚群及其相应细胞因子的表达水平存在明显异常,地塞米松能干扰SLE患者体内细胞因子网络失衡的免疫病理过程,且对IL-17有明显的抑制作用,为临床使用糖皮质激素治疗SLE提供新的理论依据和实验室基础.

Objective To investigate the effects of dexamethasone（DEX）on the secretion of interleukin （IL）-17 and interferon（IFN）-γ and the proportion of Th17,Tc17,Th1 ,Tc1 cells in peripheral blood mononuclear cells（PBMCs）of patients with systemic lupus erythematosus（SLE）. Methods Thirty hospitalized SLE patients were recruited and twenty-two healthy volunteers were recruited as healthy controls. PBMCs were separated from SLE patients and healthy controls and then was cultured in vitro by medium or PMA/Ionomycin or PMA/Ionomycin ＋dexamethasone for six hours. Four- color immunofluorescent staining and flow cytometric assay were used to analyze the percentage of Th17,Tc17,Th1,Tc1 cells in PBMCs. Concentrations of IL-17 and IFN-γ in plasma and the supernatants of PBMCs which were cultured for 24 hours were measured by enzyme linked immunosorbent assay （ELISA）. Results The plasma concentrations of IL-17 and IFN-γwere elevated in SLE patients as compared to the controls（P 〈 0.05）. No significant differences were observed between patients and controls for the spontaneous production of IL-17 and IFN-γ or percentage of T subsets expressed by PBMCs. After the stimulation of PMA,compared with the controls,the level of IL-17 was significantly elevated in the supematants of PBMCs and the percentages of Th17 and Tc1 in SLE patients increased significantly（P 〈 0. 05）. However,there showed no significant differences between SLE patients and the controls for the percentages of Th1 and Tc17 cells. DEX could significantly decrease the production of IL-17（P 〈 0. 01）and the percentages of Th17,Tc1 cells by the active PBMCs（P 〈 0. 05）. Conclusions There is abnormal expression of T subset cells and their cytokines in vivo of SLE patients. DEX can interfere with immunological pathological process in the cytokine network imbalance of SLE patients and shows powerful inhibition of IL - 17. Our results may provide some laboratory evidence for the clinical application of corticosteroids.