Attenuated Viable Bcg Bronchial Asthma Mouse Toll-like Receptor 4 Expression And Cytokine Levels

ObjectiveWe treated the mice of bronchial asthma with attenuated active Bacille Calmette-Guerin vaccine and observed the changes,suan as the total cellular score and eosinophils granulocyte in bronchoalveolar lavage fluid,and the inflammation of lung tissue in pathological section,the level of cytokines IL-4,IL-5 and IFN-γin spleen cell culture supemant,the level of IgE in serum,the expression of Toll-like receptor 4 on the lungs of mice with bronchial asthma.To approach the effect of Toll-like receptor 4 mediated immunotherapy in attenuated active Bacille Calmette-Guerin vaccine onto bronchial asthma.To provide evidences with the mechanism of action of attenuated active Bacille Calmette-Guerin vaccine.MethodsKunming mouse were allergized and stimulated by egg albumin to set up the model of asthma.They were given a small dose of attenuated active Bacille Calmette-Guerin vaccination.Within the 24 hours after the last stimulation by antigen,we collected the bronchoalveolar lavage fluid to count the total cellular score and eosinophils granulocyte in it.We observed the inflammation of the lung tissue and the distincive eosinophils granulocyte of the asthma mice in pathological section.We prepared the spleen cell suspension to detecte the content of IL-4,IL-5 and IFN-γin the supernatant of cultured spleen cells medium by ELISA. We get the blood from left ventricular to detecte the content of IgE in serum by ELISA.We took the sample of lung tissue to detecte the expression of Toll-like receptor 4 by the method of western blotting, immunohistochemistry and RT-PCR. Results(1)The total cellular score and eosinophils granulocyte in the bronchoalveolar lavage fluid of the Bacille Calmette-Guerin vaccine treated group are obviously lower than the asthma group,and the inflammation of the lung tissue in pathological section is lightened.(2)According to the results of ELISA,the level of IL-4,IL-5 in spleen cell culture supernant of the Bacille Calmette-Guerin vaccine treated group are obviously lower than the asthma group,the level of IFN-γ, upgraded,and the level of IgE in serum degraded.(3)According to the results of western blotting,immunohistochemistry and RT-PCR,the expression of Toll-like receptor 4 of the Bacille Calmette-Guerin vaccine treated group is relatively up-regulated than the asthma group,and the expression is markedly up-regulated than the control group.ConclusionThe mice of bronchial asthma were treated by attenuated active Bacille Calmette-Guerin vaccine.The immunological regulatory mechanism of Toll-like receptor 4 is started through the up-regulation of Toll-like receptor 4 expression.and than the Th₁ immune response in organism is enhanced.The content of IL-4,IL-5 in spleen cell culture supernant degraded obviously.The content of IFN-γupgraded obviously.Among this,IFN-γ,is Th₁ cytokine,while the IL-4,IL-5 are Th₂ cytokines.It corrects the disequilibrium of Th₁/Th₂ in asthma and relieves the inflammation of anthma.The total cellular score and eosinophils granulocyte in the bronchoalveolar lavage fluid degraded.And the pathological section of the lung tissue also shows that the inflammation of the mice airway is obviously relieved.The experiment shows that Toll-like receptor 4 participates in the therapy of bronchial asthma. Toll-like receptor 4 mediates the immunotherapy effect of attenuated active Bacille Calmette-Guerin vaccine on bronchial asthma.