Objective:To study the effects of Mycobacterium vaccae vaccine on eosinophil apoptosis

protein expression of Fas and bcl-2 in lung tissues of asthmatic guinea pig.Methods:30 guinea pigs were randomly divided into NS

asthma and Mycobacterium vaccae vaccine group.A guinea pig model of asthma was estbalished with OVA(ovalbumin).Each guinea pig of Mycobacterium vaccae vaccine group was injected intramuscularly with 22.5μg of Mycobacterium vaccae vaccine 10 days before OVA immunization.After the last challenge

TdT-mediated dUTP nick end labeling (TUNEL)technique was used to determine the apoptosis of eosinophils and immunohistochemistry method was used to determine protein expression of Fas and bcl-2 in lung tissue sections.Results:Guinea pigs of Mycobacterium vaccae vaccine group had a higher AI(apoptosis index) of eosinophils in lung tissues[(23.8±5.4)%]than that of asthma group[(4.6±0.7)%

P<0.01]

a higher expression of Fas protein(optical density value

OD value)in lung tissues[(0.202±0.013)]than that of asthma group[(0.051±0.025)

P<0.01]

and a lower expression of bcl-2 protein(OD value)in lung tissues[0.054±0.032)]than that of asthma group[0.181±0.041)

P<0.01].Conclusion:Mycobacterium vaccae vaccine can induce the apoptosis of eosinophils in lung tissues of asthmatic guinea pigs by up-regulating the expression of Fas protein and down-regulating the expression of bcl-2 protein in lung tissues.