地塞米松对支气管哮喘急性发作患者外周血T淋巴细胞亚群自噬的影响

摘要

Objective To explore the effects of Dexamethasone on the autophagy of peripheral blood T lymphocyte subpopulations in patients with acute episode of bronchial asthma. Methods T cell subsets ( CD4+ T, CD8+ T and CD4+ CD25+ T cells ) were isolated from peripheral blood in acute asthma and healthy people, and then were cultured with 10 -5 mol/L Dex. Morphological features of the autoph-agy were observed by electron microscopy ( TEM ) and fluorescent microscopy. After monodansylcadaverine ( MDC ) staining, the expres-sion of Foxp3 in CD4+ CD25+ T cells were quantitated by flow cytometry. Results First, the typical morphological autophagic features of T cells can be observed after cultivation with Dex. Second, autophagy could be up-regulated by Dex in CD4+ T and CD4+ CD25+ T cells in a-cute asthma ( P < 0. 05 ), and there were a time-dependent along with the increase of autophagy levels ( P < 0. 05 ). Third, the expression of Foxp3 in CD4+ CD25+ T cells significantly decreased in asthma, and Dex did not affect the Foxp3 levels in acute asthma ( P >0. 05 ). Conclusions The Autophagy increment in asthmatic peripheral T cell subsets induced by GCs may be one of the mechanism of GCs in asthma.%目的 本文拟研究地塞米松对哮喘急性发作患者外周血T淋巴细胞亚群自噬的影响.方法 分离哮喘组及健康者外周血T淋巴细胞亚群(CD+4 T,CD+8 T和 CD+4CD+25 T 细胞),分别与地塞米松(10-5 mol·L-1)共培养.首先以电子显微镜及荧光显微镜观察培养后细胞的自噬形态学改变;然后丹(磺)酰戊二胺(MDC)染色后,以流式细胞术检测上述细胞的自噬水平及CD+4CD+25 T细胞的Foxp3表达.结果 ①镜下可观察到与地塞米松共培养后细胞的典型自噬形态学改变;②地塞米松可以上调哮喘组外周血CD+4 T和 CD+4CD+25 T 细胞的自噬率(P<0.05),自噬水平的升高均呈时间依赖性 (P<0.05);③哮喘组CD+4CD+25 T细胞的Foxp3表达显著低于健康对照组(P<0.05),但地塞米松预处理对Foxp3的表达无影响(P>0.05).结论 地塞米松诱导哮喘急性发作患者外周血T淋巴细胞亚群自噬水平的增高可能是糖皮质激素治疗哮喘的作用机制之一.