哮喘小鼠气道上皮TSLP表达及激活DCs加重气道炎症的研究

目的 研究支气管哮喘小鼠气道上皮中胸腺间质淋巴细胞生成素(TSLP)表达,探讨其对哮喘小鼠肺部炎症的影响.方法 BALB/c小鼠分为生理盐水对照组、哮喘模型组和TSLP中和抗体干预组.通过气道反应性和肺组织病理学评价哮喘模型;酶联免疫吸附试验(ELISA)检测支气管肺泡灌洗液(BALF)上清中IL-4、IL-5和IL13的含量;实时荧光定量PCR(qRT-PCR)测定肺组织中TSLP mRNA的表达;免疫组化及Western blot法测定肺组织中TSLP蛋白的表达;流式细胞术检测BALF中树突状细胞(OCs)表面CD40、CD80、CD86的表达水平.结果 小鼠气道反应性增高和肺组织病理学检查结果均符合哮喘的典型表现证实造模成功;哮喘组BALF中IL-4、IL-5和IL-13的水平显著高于正常组(P<0.05),且TSLP与其成正相关;与正常对照组相比,哮喘组气道上皮TSLPmRNA和蛋白高表达,两组间差异有统计学意义(P<0.05);哮喘组BALF中DCs表面CD40、CD80、CD86表达明显高于正常组(P<0.05).TSLP中和抗体干预后,BALF中DCs表面CD40、CD80、CD86表达明显减低,并进一步减少IL-4、IL-5和IL-13的表达.结论 哮喘气道上皮中TSLP表达增高,TSLP通过上调DCs表面CD40、CD80、CD86的表达,激活DCs诱导CD4~+T细胞向Th2分化发育,与加重哮喘的气道炎症有关;TSLP抗体干预可阻断DCs的活化,减少Th2细胞因子的分泌,这些因素可能与减轻哮喘炎症反应有关,为哮喘治疗途径提供新的思路.

TSLP promotes lung Inflammation via activating dendritic cells in OVA-induced mice asthmatic model

Objective To study the expression of thymic stromal lymphopoietin(TSLP) and the activation of DCs in OVA-induced murine asthma model, and investigate the effects and underlying mecha-nisms of TSLP on lung inflammation. Methods Thirty BALB/c mice were randomly divided into control group, OVA group and TSLP neutralizing antibody treated group. The asthma model was evaluated by airway responsiveness and histological analysis of lung tissues ; The levels of TSLP mRNA in lungs were determined by quantitative real-time PCR; The expression of TSLP in lungs were determined by immunohistochemistry and Western blot; The expression of CD40, CD80, CD86 in BALF was detected by FACS. Results Both the histological analysis of lung tissues and the airway responsiveness were all consistent with the characteris-tic of murine asthma model. The expression of TSLP and TSLP mRNA in the OVA group was significantly in-creased compared with blank group. The expression of CD40, CD80, CD86 in BALF from OVA group was increased significantly compared with the control group. Furthermore, treating mice with TSLP neutralizing antibody reduced the expression of CD40, CD80, CD86 on dendritic cells, and IL-4, IL-5, IL-13 in the OVA group. Conclusion Our study indicate that TSLP was highly expressed in the bronchial epithelia of murine asthma model, via upregulation of CD40, CD80, CD86, induce DCs to active CD4~+ T cells and pro-duce type 2 responses, so that aggravating the lung inflammation of asthma. Blocking TSLP is capable of in-hibiting the production of Th2 cytokines, thus presents a promising strategy for the treatment of asthma.