Study On The Effect Of Schistosoma Japonicum Infection On Asthma

Objective This study aimed at establishing the animal model of Schistosomajaponicum infection-asthma, and studying the effect of Schistosoma japonicuminfection on asthma.Methods Twenty-five BALB/c mice were divided into three groups at random.Groupâ… was infection-asthma group, Groupâ…¡was asthma group, Groupâ…¢wascontrol. The mice in Groupâ… were infected with 23±3 Schistosoma japonicumcercarie through skin of abdomen on Day 1. The mice in Groupâ… and Groupâ…¡weresensitized intraperitoneally(i.p.) with 100μg ovalbumin(OVA) in 2mg of KA1 (SO₄)₂adjuvant on Day 57 and Day 71 respectively. On day 78-84, the mice in Groupâ… andGroupâ…¡were challenged intranasally with 50μg of OVA, and were sacrificed bycervical vertibva dislocation On day 85. Then all the mice were dissected to obtainspleens. Single-cell suspensions were prepared and cultured at 7.5×10⁶ cell/ml(1ml/well),with OVA (1mg/ml) at 37℃. Culture superatants were harvested at 72 hfor measurement of narious cytokine (IL-4,IFN-γ) using ELISA. The thoracic cavitiesof all the mice were cannulated and the lungs were washed four with 0.5ml PBS. TheBAL fluids were collected and the cell pellet was smeared after centrifugation. Thespecimens were stained.200 cells were counted per specimen to calculate thepercentage of eosinophile. After BAL, the right lobe of the lungs was cut forhistological analysis. Sections were stained with hematoxylin and eosin for theassessment of inflammatory response in lungs.Result 1. The results indicated that the BALF from asthma-group contained lots ofinflammatory cells, most of which were eosinophile granulocyte, about(43.60±2.53)%. The BALF from the mice of infection-asthma group also contained lots of inflammatory cells, in which, the eosinophile granulocytes occupied(7.30±5.00)%. The BALF from the mice of control contained some epithelial cells,but no eosinophile granulocyte.2. IL-4, IFN-γlevels were measured by cytokine-specific ELISA. IL-4 level ininfection-asthma group was (49.33±25.46) pg/ml, and in asthma group was(529.46±397.58) pg/ml, and in control group was (12.77±1.76)pg/ml. IFN-γlevel in infection-asthma group was (0.18±0.01) pg/ml, and in asthma group was(0.19±0.03) pg/ml, and in control group was (0.19±0.03) pg/ml.3. Histology analysis: Mice in Groupâ…¡had significant pulmonary inflammation.There were amounts of goblet cell hyperplasia, interstitial inflammation, andperivascular and peribronchiolar cuffing with an infiltration of lymphocytes andeosinophils in lungs. Mice in Group I had significant reductions in pulmonaryinflammation compared with mice in Groupâ…¡. And no inflammation was found inthe lungs of those in Groupâ…¢.Conclusion Schistosomajaponicum infection can inhibit the asthma.