Influence of different administration methods of Bacillus Calmette-Guérin on airway tissue in mice with asthma

Objective To evaluate the effects of intranasal and subcutaneous Bacillus Calmette-Guerin(BCG) administration on the airway tissue in asthma mice models.Methods Twenty-eight BALB/c mice were divided into normal group,asthma group,intranasal-BCG group and subcutaneous-BCG group,with 7 mice in each group.Normal group was sensitized with saline,asthma group was sensitized with dermatophagoides farinae(Der f),and intanasal-and subcutaneous-BCG group were inoculated with BCG 1×105CFUs while they were simultaneously sensitized with Der f.After one month,the numbers of eosinophils and lymphocytes were counted in bronchoalveolar lavage fluid(BALF) and lung tissue,and the proliferation of goblet cell and the thickness of smooth muscle were measured.Results The number of eosinophils of BALF was lower in normal group((0.34±0.12)%),intanasal-BCG group((0.43±0.21)%) and subcutaneous-BCG group((0.58±0.18)%) than that in asthma group((5.54±1.02)%)(P0.05).There was no significant difference in the number of lymphocytes in BALF among the four groups(P0.05).The numbers of eosinophils and lymphocytes of lung tissue were lower in normal group,intanasal-BCG group and subcutaneous-BCG groups than those in asthma group(P0.05).The number of eosinophils was lower in subcutaneous-BCG group((17.40±3.20) /mm2) than that in intanasal-BCG group((36.96±5.86) /mm2)(P0.05).The goblet cell proliferation was lower in the normal group,intanasal-BCG group and subcutaneous-BCG group than that in asthma group(P0.05),and lower in subcutaneous-BCG group than that in intanasal-BCG group(P0.05).The thickness of smooth muscle was less in intanasal-BCG group((32.89±5.02)×10-1μm) than that in asthma group((54.41±8.32) ×10-1 μm)(P0.05).Conclusion Both of the administration methods can suppress asthmatic responses in airway tissue,and subcutaneous administration is more effective than intanasal administration.