[Effect of interferon-gamma on antigen-induced eosinophil infiltration in mouse airway]

Repeated aerosolized ovalbumin (OVA) challenge of OVA-sensitized mice induces bronchoalveolar lavage fluid (BALF) eosinophilia. The influence of interferon-gamma (IFN-gamma) on antigen-induced eosinophil recruitment in the airway as well as the concentration of interleukin-5 (IL-5) in supernatants of cultured spleen cells were examined. In sensitized mice challenged with OVA 20 minutes once a day for 6 days, the number of BALF eosinophils was (9.53 +/- 0.84) x 10(8)/L. However, no eosinophil could be found in the BALF from mice without OVA sensitization and challenge. In mice treated with intraperitoneal injection of INF-gamma before each challenge, different doses of IFN-gamma (1.0 x 10(3) U/kg, 1.0 x 10(4) U/kg and 1.0 x 10(5) U/kg) produced different degrees of eosinophilia inhibition 29.8% (P < 0.05), 55.7% (P < 0.01) and 69.0% (P < 0.01). Our results showed that IFN-gamma prevented antigen-induced eosinophil infiltration in airway accompanied by a decrement of levels of IL-5 with a dose related response. It is concluded that IFN-gamma is capable of inhibiting eosinophil infiltration in mouse airway by inhibiting the production of IL-5. Our results suggested that IFN-gamma may be of value in eliminating asthmatic airway inflammation in humans.