Effect of live mycobacterium bovis Bacille Calmette-Guérin vaccination on the regulation of IL-17 in asthma mice

Objective To investigate the effect of live mycobacterium bovis Bacille Calmette-Guerin vaccination on the regulation of IL-17 in mice asthma model.Methods 30 female BALB/c mice were randomly divided into 3 groups:group A(control group),group B(asthma group) and group C(BCG group).The mice of group B and C were sensitized by OVA and then stimulated with nebulized OVA,and live BCG were inoculated 14 days before sensitized in group C.The airway inflammation was evaluated by HE staining.Inflammatory cell numbers and morphological identification of leucocytes in bronchoalveolar lavage fluid (BALF) were measured by light microscopy.The levels of interleukin-17 in mice bronchoalveolar lavage fluid (BALF)and serum were measured by enzyme-linked immunosorbent assay (ELISA).Results The neutrophil and eosinophil infiltration in pulmonary tissue was dramatically increased in group B,but no such change in group A and was lighten in group C.The total cell number and the percentages of eosinophils and lymphocytes in BALF of the mice in group B and C were significantly higher than that of group A(P0.01) ,and the percentages of eosinophils in the mice of group C was decreased when compared with that of group B(P0.01).The level of IL-17 in BALF was significantly higher in group B and C than group A(P0.01).In the asthmatic mice,IL-17 expression in the serum and BALF was positively correlated with the percentages of eosinophils in the BALF(P0.01).Conclusion Live BCG vaccination can effectively prevent the development of airway inflammation associated with altered IL-17 levels.