Study on the effect of Schistosoma japonicum infection on allergic asthma

Objective To establish an experimental animal model of Schistosoma japonicum infection complicated by asthma,and study the effect of S.japonicum infection on asthma. Methods Twenty five BALB/c mice were randomly divided into three groups.Group A was infection-asthma group,Group B was asthma group,Group C was control.The animals in Group A were infected with 23±3 S.japonicum cercarie through skin of abdomen.8 weeks later,the animals in Group A and Group B were sensitized and challenged intranasally with OVA,in order to establish experimental animal model.After 12 weeks spleen cells were collected and single-cell suspensions were cultured for 72 h.Culture supernatants were harvested for measurement of IL-4 and IFN-γ.The BALF fluids were collected to analysis the percentage of eosinophile.The left lungs were cut for histopathological analysis. Results Compared with Group B,the number of EOS in BALF of mice in Group A was decreased(P0.05).The percentage of EOS of mice in Group A and Group B were(7.3±5.01)%,(43.6±2.53)%,respectively,while there was no inflammatory cells,but only a few bronchial epithelial cells in BALF of mice in Group C.IL-4 and IFN-γ levels were measured by cytokine-specific ELISA.IL-4 levels in Group A,B and C were(96.02±38.54) pg/ml,(414.86±175.12) pg/ml and(13.55±1.66) pg/ml,respectively.IFN-γ levels in Group A,B and C were(11.60±4.19) pg/ml,(7.43±3.60) pg/ml and(7.55±1.57) pg/ml,respectively.Compared with Group B,IL-4 level in Group A decreased(P0.05),and the ratio of IL-4/IFN-γ was also decreased(P0.05),but there was no significant difference between IFN-γ levels of Group A and Group B(P0.05).Compared with mice in Group B,the pulmonary inflammation of mice in Group A decreased significantly(P0.05),while there was no pulmonary inflammation of mice in Group C.Conclusion S.japonicum infection can inhibit the asthma.