SGK1调节T细胞亚群失衡在儿童哮喘中的作用

SGK1-induced imbalance of T lymphocyte subsets in childhood asthma

目的：探讨SGK1在儿童哮喘T细胞中的表达及对T细胞分化的影响,揭示SGK1调节T细胞分化在儿童哮喘中的作用。方法收集在西安市儿童医院收治的儿童支气管哮喘患儿28例,依据临床诊断进行分级。通过ELISA分别检测IL-4、IL-13和IL-17A在哮喘患儿血清中的表达水平。从哮喘患儿外周血（ peripheral blood mononuclear cells,PBMC）中,磁珠分选CD4^＋T细胞,通过Real-time PCR检测SGK1的表达。从PBMC中分选获得Na？ve T细胞,体外诱导分化,通过Real-time PCR检测SGK1在Th1、Th2和Th17细胞中的表达。以siRNA干扰SGK1,FCM分别检测Th2和Th17细胞分泌IL-4和IL-17A的能力。构建哮喘小鼠模型,以shRNA-SGK1 Naive T细胞静脉回输,观察shRNA-SGK1对哮喘气道炎症的影响。结果与健康儿童相比,哮喘患儿血清中IL-4、IL-13和IL-17A的水平明显升高,且随病程进展,血清中这三种因子的水平越高。哮喘患儿中,SGK1在外周血CD4^＋T细胞中的表达显著升高,且SGK1的表达与IL-13和IL-17A呈明显正相关。在体外诱导分化的Th2和Th17细胞中,SGK1的表达明显升高,而在Th1细胞中表达变化不明显。抑制SGK1的表达,Th2和Th17相关的细胞因子IL-4和IL-17A都明显下降。在体内,shRNA-SGK1抑制了哮喘小鼠IL-13和IL-17A的血清水平,气道炎症明显降低。结论高表达的SGK1通过调节T细胞亚群的分化促进了儿童哮喘的进展。

Objective To study the expression of SGK1 in T lymphocytes from pediatric asthma,and the effect of SGK1 on the differentiation of T cells,also to explore the function of SGK1 regulating the differen-tiation of T subset in pediatric asthma. Methods Twenty-eight children with asthma were recruited in Xi′an children′s hospital and divided into moderate group and severe group according to diagnostic guideline of asth-ma. The serum levels of IL-4,IL-13 and IL-17A were analyzed by ELISA. The CD4^＋T cells from PBMC and naive T cells were selected using magnetic beads. Na？ve T cells were differentiated in vitro under cytokines. SGK1 expression were analyzed with Real-time PCR. The ability of Th2 and Th17 on secreting IL-4 and IL-17A were detected after SGK1 was inhibited by siRNA. In vivo,shRNA-SGK1 Na？ve T cells were transferred into the mice asthma models by intravenous injection. The airway inflammation were observed in shRNA-SGK1 Na？ve T models. Results Compared with healthy children,the serum levels of IL-4、IL-13 and IL-17A increased signifi-cantly in the children with asthma. Importantly,the levels of these three cytokines were much higher with the de-velopment of asthma. SGK1 were up-regulated remarkably in CD4^＋T cells from the children with asthma and were positively correlated with IL-13 and IL-17A. Besides,SGK1 expression increased in the differentiated Th2 and Th17 in vitro,but had no change in the differentiated Th1. The levels of IL-4 and IL-17A associated with Th2 and Th17 decreased after SGK1 was inhibited by siRNA. Similarly,In vivo,the serum levels of IL-13 and IL-17A and airway inflammation were reduced in shRNA-SGK1 Naive T models. Conclusion The over-expres-sion of SGK1 in pediatric asthma enhances the asthma progress by promoting the differentiation of T subsets.