Aerosolized recombinant interferon-gamma prevents antigen-induced eosinophil recruitment in mouse trachea

In a murine model of airway late-phase reaction we have previously shown that antigen-induced eosinophil recruitment into the airways of sensitized mice is mediated by CD4+ T cells and interleukin-5. To determine whether interferon-gamma (IFN-gamma) regulates antigen-induced eosinophil recruitment into the airways, we studied the effect of aerosolized recombinant murine IFN-gamma on the eosinophil infiltration of the trachea induced by antigen inhalation in mice. The administration of aerosolized rIFN-gamma prevented antigen-induced eosinophil infiltration in the trachea of sensitized mice. The administration of aerosolized rIFN-gamma also decreased antigen-induced CD4+ but not CD8+ T-cell infiltration in the trachea. However, there were no significant changes in the number of blood eosinophils or of splenic CD4+ and CD8+ T cells in the treatment with rIFN-gamma. These results indicate that locally administered IFN-gamma prevents antigen-induced eosinophil recruitment into the airways by inhibiting CD4+ T cell infiltration.