The Experimental Studies About Effect Of BCG ON The Airway Inflammation Of Asthma

Objective: To study the effect of Bacillus Calmette-Guerin(BCG) on airway inflammation of asthma model;To explore the change of IL-4 and IL-10 in spleen mononuclear cell culture supernant,expression of GATA-3 in pulmonary tissue,CD4+CD25+Treg cells in peripheral blood and explain mechanism of effect of inhibition about BCG on airway inflammation.Method:Male KunMing mice (6-8week weight 18-22g) were randomly divided into four groups,each group eight mice.1)Asthma Group: eight mice were sensitized with injection intraperitoneally 10%Ovalbumin(OVA) and 10% aluminum hydroxide and challenged by inhaling aerosol 1%OVA to establish asthma mouse model.2)Early treament with BCG group: eight mice were sensitized/challenged with the same protocol used by asthma group, but these mice were treated with injection intracutaneously BCG 0.025mg 5 day before and after OVA sensitization. Latter treament with BCG group: eight mice were sensitized/challenged with the same protocol used by asthma group,however, these mouse were treated with injection intracutaneously BCG 0.025mg in one hour after the last challenge.Normal control group: As a negative control, eight mice were sensitized/challenged by saline instead of OVA.Twenty-four hours after the final challenge, all mice were killed. Bronchoalveolar Lavage Fluid (BALF) was collected from each mice to count the total number of cells and eosinophils. The level of IL-4 and IL-10 in the spleen mononucular cell culture supernant was determined with ELISA. CD4+CD25+Treg cells in peripheral blood were analyzed by flow cytometry.Sections from lung tissue were performed and stained using standard histological protocol with HE. The expression of GATA-3 was also evaluated by immunohistochemistry.