ABSTRACT
Objective:To explore the Immunoprotection of gastric mucosa in newborn mice after oral immunization with inactived H.pylori.Methods:Thirty-two BALB/c mice were randomly divided into four groups, including PBS control group ( groupⅠ) ,the group of inactivated H.pylori ( groupⅡ) , the group of inactivated H.pylori and Escherichia cole heat-labile enterotoxin B subunit( LTB) ( groupⅢ) ,and normal group( groupⅣ).Newborn BLAB/c mice within 24 hours were immunized through oral gavage with corresponding antigen,Two weeks after final immunization,the mice were challenged with 1×108CFU live H.pylori strain SS1, twice once day,for 2 days.The twenty-eighth day post-challenge,all of mice were sacrificed and stomachs were removed for grades of in-flammation and The counting of H.pylori colonizing.Results:The mean scores of stomach tissue inflammation of groupⅠ,Ⅱ,Ⅲ andⅣwere 2.25±0.46,2.12±0.35,1.5±0.53,0.25±0.46,respectively,and the score of inflammatory activity of the above four groups were 2.12±0.35,2.12±0.35,1.37±0.52,0.25±0.46.Among these four groups,the results were statistically significant between any two groups except the result between groupⅠand groupⅡ.Finally,H.pylori colonization quantity in the stomachs of groupⅢwas lower than groupⅠand group Ⅱ( P<0.05 ) , as expected, the H.pylori colonization was undetectable in group Ⅳ.Conclusion: The oral gavage with inactived H.pylori plus LTB to newborn mice may be associate with the lightening of inflammation and the decrease of H.pylori colonizing number.
ABSTRACT
Objective To investigate the mechanism of therapeutic action of dexamethasone on asthmatic mice by detecting the levels of IL-25 and IFN-γ in bronchoalveolar lavage fluid (BALF). Methods Balb/c mice with SPF grade were randomly divided into normal control group, asthma group and dexamethasone group. Asthma group and dexamethasone group were sensitized and challenged with ovalbumin ( OVA) . Dexamethasone group was intraperitoneally injected with dexamethasone one hour before challenging. The mice were executed 24 hours after the last challenge, and the HE stained pathological sections of the right lung were made. Pathological sections of lung were observed. BALF in the left lung was also collected. The total white blood cell count and absolute eosinophile ( EOS) count were observed, and the percentage of EOS was calculated. The levels of IL-25 and IFN-γwere measured with ELISA, and correlation analyses were made. Results The counts of total white blood cell and EOS, and the percentage of EOS were significantly higher in the asthma group than in the normal control group and dexamethasone group (P<0. 05). No differences were found between the normal control group and dexamethasone group. The IL-25 level was higher in the asthma group than in the normal control group and dexamethasone group (P<0. 05), and its level in the dexamethasone group was also higher than that in the normal control group. The IFN-γlevel was lower in the asthma group than in the normal control group and dexamethasone group (P<0. 05), while there was no significant difference between the normal control group and dexamethasone group. IL-25 was negatively correlated with IFN-γin each group. Conclusion Part of the mechanisms of dexamethasone acting on asthma are related to its inhibition on the pulmonary inflammation and promotion on the expression of IFN-γ, and possible inhibition of IL-25 expression.