Effects Of Oral Bacillus Calmette-Guerin On Airway Inflammatory Cell And Peripheral Blood Th1/Th2 Balance In A Mouse Model Of Asthma

Objective To explore effects of oral Bacillus Calmette-Guerin(BCG) on airway inflammatory cell and peripheral blood eosinophlia(Eos) and Th1/Th2 balance in a mouse model of asthma at the single-cell level.Methods Mouses were sensitized and challenged with ovalbumin(OVA) to established an asthmatic model ,and asthmatic animal model was made successfully.We explored an optimal dose of oral BCG inhibiting the numbers of Eos in bronchoalveolar lavage fluid (BALF). 32 Male BABL/c mouses(6-8weeks of age,18±2g of weight) were divided into four groups: control group, ovalbumin-sensitized group , intradermal-injection BCG+ovalbumin-sensitized group,oral BCG+ovalbumin-sensitized group. Mouses in intradermal injection group were injected with BCG intradermally 8 weeks before the first OVA challenge, Mouses in oral BCG group were administered orally 8 weeks before the first OVA challenge. BALF was collected,Then IL-4 and IFN-γ in BALF as well as the peripheral blood were analysed by ELISA,and all kinds of leukocyts numbers were counted, and the peripheral blood Th1/Th2 ratio was detected by using three-color flow cytometry method.Results We choosed BCG(10mg) as the optimal dose inhibiting airway Eos. We found the total leukocytes and the other numbers significantly increased in BALF after OVA challenge compared with control group, The numbers of lympocytes, Eos, neutrophils in BALF of asthmatic group significantly increased, The numbers of lymphocytes, macrophages in BALF of BCG infection group significantly increased , P<0.01.Compared with asthmatic group,oral BCG and in intradermal injection group resulted in reduction in Eos 50%numbers of the BALF, P<0.05, Macrophages in BALF of BCG infection groups significantly increased, P<0.05 .