卡介菌多糖核酸对哮喘大鼠外周血单个核细胞IFN-γmRNA表达影响研究

The effect of BCG-PSN on the expression of the IFN -γmRNA in the peripheral blood mononuclear cells from asthma rats

目的从分子水平探讨卡介菌多糖核酸对支气管哮喘TH1型细胞因子IFN-γmRNA表达的影响。方法SD大鼠24只,随机分成盐水对照组、BCG组和哮喘组3组,每组8只,用OVA联合AL(OH)3腹腔注射建立大鼠哮喘模型并以OVA雾化吸入激发哮喘,对各组动物做行为学观察、支气管肺组织学检查,支气管肺泡灌洗并涂片,采用逆转录-聚合酶链式反应(RT-PCR)半定量测定卡介菌多糖核酸对哮喘大鼠外周血单个核细胞中IFN-γmRNA表达的影响。结果BCG组哮喘大鼠外周血单个核细胞中IFN-γmRNA表达明显增加,强于哮喘组和正常组,经统计学检验P<0.05。结论卡介菌多糖核酸能明显增强哮喘大鼠外周血单个核细胞中TH1类细胞因子IFN-γmRNA的表达量,从而逆转TH1/TH2失衡,因此可能成为哮喘免疫治疗的理想药物。

Objective To investgate the effect of BCG-PSN on the expression of the interferon-γ(IFN-gamma) mRNA which are the presentative Th1 cytokine in the airway inflammation of asthma . Methods The 24 BN rats were randomly divided into saline control group, BCG group, as well as asthma group equally. the rat models of asthmatic inflammation were established by sensitizing to ovalbumin (OA) and alum. two weeks later, the BCG and saline were administered intraperitoneally for 7 consecutive days to SD rats respectively in the BCG and saline groups, Then challenged with 10% ovalbumin aerosol to induce allergic bronchial inflammation. 24 hours later after the last provocation, the animals were anaesthetized. Thereafter, bronchoalveolar lavage (BAL) was performed and the peripheral blood were collected. Total RNA was extracted from peripheral blood and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using primers for IFN-γand beta-actin. Results In BCG group the allergic symptoms and inflammation cells infiltrated into the mucosa of bronchitis and lungs were hardly observed in rats ,most importantly. IFN-γmRNA extracted from peripheral blood was increased significantly compared with the saline and asthma group(P<0.05). Conclusion BCG can significantly increase the expression of IFN-γmRNA in rats asthmatic model.so as to raise the ifn/il-4 value and reverse the imbance of Th1/Th2. in whole BCG may become a potential ideal agent for the immunie treatment of asthma.