唾液乳杆菌对哮喘小鼠CD4^+CD25^+Foxp3^+Treg细胞数量及TGF-β1表达的影响

Effect of Lactobacillus salivarius on the Number of CD4^+CD25^+Foxp3^+Treg Cells and the Expression of TGF-β1 in Asthma Balb/c Mice

目的探讨唾液乳杆菌对哮喘Balb/c小鼠CD4+CD25+Foxp3+Treg细胞数量及转化生长因子β1(TGF-β1)表达的影响。方法将32只Balb/c雌性小鼠随机分成4组:正常对照组、哮喘组、唾液乳杆菌组和哮喘+唾液乳杆菌组。应用卵蛋白激发方法建立急性哮喘模型,原代提取脾细胞,应用流式细胞仪检测脾淋巴细胞中CD4+CD25+Foxp3+Treg/CD4+T比例,ELISA法测定小鼠脾细胞培养上清液中白细胞介素4(IL-4)、γ干扰素(IFN-γ)、TGF-β1水平。结果哮喘组小鼠脾细胞培养上清液中Th2细胞因子(IL-4)较正常对照组明显增高,而Th1细胞因子(IFN-γ)较对照组明显降低(P<0.05);唾液乳杆菌干预组较哮喘组Th2细胞因子(IL-4)水平下降,Th1细胞因子(IFN-γ)水平升高(P<0.05);唾液乳杆菌干预组小鼠脾细胞培养上清液中TGF-β1含量明显高于哮喘组(P<0.05);哮喘组小鼠脾淋巴细胞中CD4+CD25+Foxp3+Treg/CD4+T细胞比例较正常对照组明显减少(P<0.05),而唾液乳杆菌干预组则明显高于哮喘组(P<0.05)。结论 CD4+CD25+Foxp3+Treg参与了支气管哮喘的发病过程,唾液乳杆菌可能通过上调CD4+CD25+Foxp3+Treg数量及增加TGF-β1表达调整Th1/Th2失衡,减轻哮喘炎症。

Objective To explore the effect of Lactobacillus salivarius on the number of CD4^＋CD25^＋Foxp^3＋Treg cells and expression of transforming growth factor β1（TGF-β1）in asthma Balb/c mice. Methods Thirty-two female Balb/c mice were randomly divided into four groups：the normal control group,the asthma group,the Lactobacillus salivarius group,and the asthma combined Lactobacillus salivarius group. Acute asthma model was established by the ovalbumin challenge method. After extraction of primary spleen cells,flow cytometry was used to test CD4^＋CD25^＋Foxp^3＋Treg/CD4＋T ratio in spleen lymphocytes. The levels of IL-4,IFN-γand TGF-β1 in the spleen cell culture supernatant were measured by ELISA method. Results The level of Th2 cytokine（IL-4）in the spleen cell culture supernatant of the asthma group was significantly higher than that of the control group（P 〈0.05）,however,the level of Th1 cytokine（IFN-γ）was significantly lower than that of the control group（P 〈0.05）. The expression level of Th2 cytokine（IL-4）in the Lactobacillus salivarius intervention group was significantly decreased compared with the asthma group,and the Th1 cytokine（IFN-γ）expression level was elevated compared with the asthma group（P 〈0.05）. The level of TGF-β1 in the Lactobacillus salivarius intervention group was higher than in the asthma group（P 〈0.05）. The proportion of CD4^＋CD25^＋Foxp^3＋Treg/CD4＋T in spleen lymphocytes in the asthma group was lower than that in the control group（P 〈0.05）,and was higher in the Lactobacillus salivarius intervention group than in the asthma group（P 〈0.05）. Conclusion CD4^＋CD25^＋Foxp^3＋Treg was associated with the pathogenesis of asthma. Lactobacillus salivarius could adjust Th1/Th2 imbalance and reduce asthma inflammation through up-regulation of CD4^＋CD25^＋Foxp^3＋Treg and TGF-β1 expression.