Objective To evaluate the effects of fluticasone propionate (FP)on Foxp3 expression in CD4+T cells, to explore the possible mechanisms of childhood asthma. Methods Thirty asthmatic children, 15 with inhaled FP and 15 without inhaled FP, and 16 healthy children were recruited. Peripheral blood mononuclear cells (PBMC)labeled for CD4 and intracellular Foxp3 were analyzed using flow eytometry. The levels of IL-2 and IL-6 in serum and supernatant before and after stimulation by Phytohemagglutination (PHA)were measured by ELISA. The expression of phosphorylated signal transducer and activator of transcription 5 (STAT5)in PBMC was detected by Western-blot.Results Compared with healthy control, the percentage of CD4+ Foxp3+ cells in PBMC in asthmatic children without inhaled FP was significantly decreased. After inhaled FP and in remission stage, the percentage of CD4+ Foxp3+ cells in asthmatic children was up regulated with a decreased serum IL-6 level and an increased phosphorylated STATS expression. Conclusions Decreased Foxp3 protein expression in peripheral CD4+ T regulatory cells (Treg)is characterized in childhood asthma. Inhaled glucoeorticoid therapy of childhood asthma might be attributed to its ability of increasing Foxp3 expression by upregulation of phosphorylated STAT5 to balance the T cell response.%目的 研究哮喘患儿吸入丙酸氟替卡松后外周血CD4+细胞的Foxp3的表达和变化,从而探讨儿童哮喘发生的可能机制.方法 以30例确诊哮喘患儿为研究对象,随机分为未治疗哮喘组(15例)、吸入丙酸氟替卡松缓解组(15例),同期16例正常儿章为对照组.流式细胞仪检测外周血单个核细胞中的CD4+Foxp3+细胞比率,ELISA检测血浆和植物血凝素(PHA)体外刺激T细胞后上清液的IL-2、IL-6水平,Western blot检测外周血单个核细胞中磷酸化STAT5和非磷酸化STAT5的水平.结果 哮喘组儿童外周血单个核细胞的CD4+Foxp3+细胞百分率低于正常对照组.与哮喘组相比,吸入丙酸氟替卡松缓解组儿童的CD4+Foxp3+细胞百分比有明显增高,血清IL-6水平降低而外周血单个核细胞磷酸化STAT5表达上调.结论 哮喘儿童的外周血CD4+细胞的Foxp3表达下凋,吸入激素可能通过上调磷酸化STAT5表达,诱导T细胞Foxp3表达,平衡T细胞应答,从而治疗儿童哮喘.
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