Effect of intraperitoneal injection of IFNγ on GATA-3 expression and airway inflammation in lungs of mice with asthma

Objective:To investigate the preventive and therapeutic effects of intraperitoneal injectoin of IFNγ on bronchial asthma in mice and the relevant mechanism. Methods: Thirty-six BALB/c mice were randomly equalized into 3 groups:group A (normal control group),group B (asthmatic model group) and group C (IFNγ treated group). The asthmatic model was established in group B and C by immunization with ovalbumin (OVA) absorbed to aluminum hydroxide. Mice of group B and C received 0.25 ml PBS and 5 μg IFNγ intraperitoneally on days 23 to 30 once daily prior to ovalbumin challenge,respectively. Bronchoalveolar lavage fluid (BALF) was collected on day 31 for determining the cellular composition and the concentrations of IL-4 and IL-5. Meanwhile,IgE in serum was determined. The pathological changes and the expression of GATA-3 were investigated in the lungs of mice. Results: (1) BALF eosinophils was significantly decreased in group C compared with those in group B ( vs ,P0.01). (2) BALF levels of IL-4 and IL-5 in group C were lower than those in group B ( vs and vs ,respectively,both P0.01). (3) Serum levels of total IgE and ovalbumin-specific IgE were significantly decreased in group C compared with those in group B with IgE ( vs and vs ,respectively,both P0.01). (4) H-E staining showed bronchial smooth muscle hypertrophy,mucous hyperemia,mucous layer thickening,mucous plugs in bronchial lumen and inflammatory cell infiltration around the bronchial wall in group B. While less inflammatory reaction was observed in group C. (5)Immunohistochemical results showed that expression of GATA-3 was obviously increased in group B and decreased in group C. Conclusion: IFNγ inhibits airway eosinophils infiltration,IL-4 and IL-5 production and serum total and ovalbumin-specific IgE in mice with asthma through inhibiting GATA-3 expression and Th2 reaction .