FIG. 6.

IFN-γ is required for the protective effect of BCG on Cryptococcus-induced lung eosinophilia. Six weeks prior to infection with 2 × 10⁴ CFU of C. neoformans (Crypto), 2 × 10⁵ CFU of BCG Pasteur was given intranasally to IFN-γ gene knockout (IFN-γ^−/−) mice and their wild-type C57BL/6 littermates. Thirteen days after fungal infection, BAL was performed. Eosinophil recruitment to BAL fluid was assessed by hemocytometer count of H&E-stained cytocentrifugation slides. Open columns represent the mean values ± standard deviations for a group of five IFN-γ^−/− mice, and filled columns represent the corresponding values for wild-type littermates. BCG infection of wild-type animals reduced Cryptococcus-induced BAL fluid eosinophilia (P < 0.01), whereas no reduction was found in IFN-γ^−/− animals (P = 0.3).