肺表面活性蛋白A在皮质类固醇调节哮喘小鼠树突细胞共刺激分子表达中的作用

The role of pulmonary surfactant A in corticosteroids regulating costimulatroy molecules on dendritic cells in murine asthma model

目的研究皮质类固醇激素调节小鼠哮喘模型树突细胞表面共刺激分子表达的机制,以及肺表面活性蛋白A(SP-A)在其调节中的作用。方法BALB/c小鼠30只,分为3组:哮喘组,采用卵蛋白(OVA)致敏和激发;对照组,以生理盐水代替OVA;治疗组,每次OVA激发后10min,腹腔注射地塞米松0·1mg。用免疫组化法检测SP-A在肺内的表达情况。采用LeicaDMSnk软件进行图像采集,并用Qwin软件计算小气道内棕色区域面积,取平均值,进行统计分析。分离培养脾脏树突细胞,用流式细胞仪(FACS)检测树突细胞表面共刺激分子CD80的表达变化。结果哮喘组肺组织表现为嗜酸性细胞及淋巴细胞浸润为主的炎症变化,治疗组和对照组无此变化。哮喘组的SP-A表达明显低于对照组和治疗组(P<0·01),CD80的表达率明显高于治疗组(P<0·01);哮喘组小气道内SP-A表达与树突细胞CD80阳性率呈负相关(r=-0·907,P<0·01)。结论皮质类固醇对小鼠哮喘模型的肺表面活性蛋白有明显的保护作用,可通过激发肺表面活性蛋白抑制树突细胞表面共刺激分子CD80的表达。

Objective To explore the mechanisms of corticosteroids regulating costimulatroy molecules on dendritic cells from mouse asthma model, and the role of SP-A in the process. Methods Murine asthma model was established with ovalbumin（OVA ） sensitization and challenge, and the model was confirmed by histological analysis of lung tissues. Rabbit antibody against mouse, immunohistochemical ABC method and glucose-DAB-nickel technique for staining and computer image analysis is used to check the expression of pulmonary surfactant A （SP-A） in three groups. FACS was also used to measure the expression of CD-80 on spleen derived dendritic cell from OVA-sensitized and challenged mice. Data was analysised with spss 10.0 software. Results Histological analysis of lung tissues was consistent with the characteristic of murine asthma model. The expression of SP-A in small trachea of asthma group was decreased vs. control group and dexamethasone group（P〈0.01） ;The expression rate of CD80 on spleen derived DC from asthma group was significantly increased compared with dexamethasone group（P〈0.01） ,and The expression of SP-A in small trachea of asthma group was perfect negative correlation （r=-0. 907,P〈0.01）. Conclusions Our results suggest that corticosteroids can increase the expression of SP-A in murine asthma model, and also can suppress the expression of costimulatroy molecules CD80 on DC derived from spleen of, and the mechanism maybe associated with increasing the expression of SP-A.