Levels of GM-CSF in BAL fluid. Soluble rat or mouse BAL fluid proteins were assessed by ELISA for total GM-CSF. All GM-CSF values are averages ± SD from triplicate samples of six individual rats or eight individual mice from each condition. (A) Normal rats were immunocompetent, Dex-treated rats were immunosuppressed with Dex, Dex-Pc rats were immunosuppressed and Pneumocystis infected for 4 weeks. Normal-Pc rats were immunocompetent, transtracheally inoculated with P. carinii, and sacrificed 7 days later. Normal IFN-γ + LPS rats were intranasally instilled with 1 μg IFN-γ and 0.5 μg LPS and were sacrificed 48 h later. (B) The same ELISA kit was used to assess soluble Amø protein from mice. Normal mice were immunocompetent, CD4-depl. mice were immunosuppressed by anti-CD4 antibody administration, and CD4-depl.-Pc mice were immunosuppressed and infected for 4 or 6 weeks. * (both panels), P < 0.05 versus the normal condition.