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目的观察卡介菌多糖核酸(BCG-PSN)对小鼠哮喘胸腺活化调节趋化因子(thymus and activation regulated chemo-kine,TARC)及mRNA表达的影响。方法以卵清白蛋白(OVA)致敏和激发建立小鼠哮喘模型。30只清洁级♂Balb/c小鼠随机分为3组,每组10只:正常对照组、哮喘组、BCG-PSN治疗组。末次激发24h后留取支气管肺泡灌洗液(BALF)及肺组织。BALF行细胞计数及分类;应用酶联免疫吸附试验(ELISA)法测定BALF中TARC、IL-4和IFN-γ蛋白的浓度;光镜观察肺组织病理变化;逆转录-聚合酶链反应(RT-PCR)法测定肺组织中TARC mRNA的表达;采用免疫组织化学法测定肺组织中TARC蛋白的表达。结果与正常对照组相比,哮喘组BALF中细胞总数、嗜酸粒细胞(EOS)绝对值及百分比、TARC和IL-4浓度、肺组织中TARC蛋白及mRNA的表达均增高,BALF中IFN-γ浓度低于正常对照组。经BCG-PSN干预后,BALF中细胞总数、EOS绝对数及百分比,TARC、IL-4浓度较哮喘组均下降,肺组织中TARC蛋白及mRNA的表达较哮喘组均下调,BALF中IFN-γ浓度较哮喘组增高。免疫组化显示TARC蛋白主要表达于支气管上皮细胞。BALF中TARC浓度与EOS绝对值、IL-4浓度呈正相关。结论卡介菌多糖核酸可降低TARC在肺组织中的表达,降低气道炎症。
Objective To investigate the effects of BCG-PSN on the expression of thymus and activation regulated chemo-kine (TARC) and mRNA in asthmatic mice. Methods Mouse asthma model was induced by ovalbumin (OVA) sensitization and challenge. Thirty clean-grade ♂Balb / c mice were randomly divided into three groups of 10: normal control group, asthma group and BCG-PSN treatment group. 24h after the last excitation of bronchoalveolar lavage fluid (BALF) and lung tissue. BALF were collected for cell counting and classification. The concentrations of TARC, IL-4 and IFN-γ in BALF were detected by enzyme linked immunosorbent assay (ELISA). The pathological changes of lung tissue were observed with light microscope. -PCR) was used to detect the expression of TARC mRNA in lung tissue. The expression of TARC protein in lung tissue was detected by immunohistochemical method. Results Compared with the normal control group, the total number of cells, the absolute value and percentage of eosinophils (EOS), the concentrations of TARC and IL-4 in BALF and the expression of TARC protein and mRNA in BALF of asthmatic group were significantly increased γ concentration lower than the normal control group. After BCG-PSN intervention, the total number of cells in BALF, the absolute number of EOS and percentage of TOS, IL-4 and EOS decreased as compared with those in asthma group. The expression of TARC protein and mRNA in lung tissue was lower than that in asthma group Concentration higher than asthma group. Immunohistochemistry showed that TARC protein was mainly expressed in bronchial epithelial cells. The concentration of TARC in BALF was positively correlated with the absolute value of EOS and the concentration of IL-4. Conclusion BCG polysaccharide nucleic acid can reduce TARC expression in lung tissue and reduce airway inflammation.