中文摘要：

目的观察鸡卵清蛋白诱导小鼠支气管哮喘（简称哮喘）模型中外源性间充质干细胞（mesenchymal stem cells，MSC）在哮喘小鼠肺组织气道炎症中的作用。方法45只雌性SPF级C57BL／6小鼠，体质量18-22g。随机分为对照组（P：P：P）、哮喘组（O：P：O）和MSC治疗组（O：M：O）。哮喘组与MSC治疗组第1天和第8天致敏，第15天、第16天和第17天使用OVA气道内滴入激发哮喘。MSC治疗组于哮喘造模第14天移植外源性MSC。对照组小鼠予PBS处理。三组小鼠于末次激发结束后24h（第18天）处死，取支气管肺泡灌洗液上清，ELISA检测IL-5、IL-9及β-氨基己糖苷酶；支气管肺泡灌洗液细胞计数总细胞数、嗜酸粒细胞数；取肺组织行病理切片苏木精-伊红染色观察肺部气道炎症情况。结果①MSC下调了哮喘小鼠气道局部炎症；②MSC减轻了哮喘小鼠肺组织中的炎细胞浸润；③MSC减轻了哮喘小鼠气道中的肥大细胞脱颗粒现象；④MSC抑制了哮喘小鼠过度的Th2变态反应。结论外源性MSC通过抑制Th2变态反应，减轻哮喘肺组织的气道炎症。

英文摘要：

Objective To study the suppression of allergic airway inflammation in a mouse model of asthma by exogenous mesenchymal stem cells （MSC）. Methods Forty five C57BL/6 mice were randomly divided into three groups ： control group （ 15）, asthmatic group （15） and MSC treated group （15）. Asthma and MSC treatment groups were sensitized i. p. with OVA on day 1 and 8. Then, mice were challenged with OVA by the intratracheal route on day 15,16 and 17. On day 14,exogenous MSC （1×10^6 cells in 1 ml PBS） were administered through the tail vein to mice 1 day before the first airway challenge in the MSC treated group. Control mice were treated with PBS. Mice were sacrificed on day 18. BALF were obtained and centrifuged to pellets and supernatants. Pellets recovered for cellular analysis. Supernatants were stored at-80 for biochemical analyses. The total number of cells in BALF was counted and the eosinophils. Concentration of IL-5, IL-9 in BALF were determined. To detect β-hexosaminidase activity. The paraffin embedded sections of lung tissue were stained with HE and the lung pathological changes were observed. Results （1）Airway inflammation were significantly reduced by exogenous MSC. （2）Admini- stration of exogenous MSC significantly reduced airway cellular infiltrates. （3）Mast cell degranulation were significantly reduced by exogenous MSC. O Administration of exogenous MSC reversed the Th2 Bias. Conclusions Exogenous MSC reduced airway inflammation of allergic asthmatic mice through the reversion of Th2 Bias.