Analysis of cytokines secreted by splenocytes from Pneumocystis -infected animals. Splenocytes were obtained 10 to 12 weeks after exposure, by which time Pneumocystis infection had typically cleared, and were cultured with recombinant Msg proteins, crude Pneumocystis antigens, or native Msg. A shows the results for IL-17, and B, the results for MCP3. Results for IL-17, top, represent the average of 7 P. murina exposed animals or 3 unexposed control animals (except for concanavalin A, n = 2) and bottom, the average of 2 P. murina exposed animals or results for 1 unexposed control animal. Results for MCP-3, top, represent the average of 4 P. murina exposed animals (except n = 3 for crude P. murina antigen) or 2 unexposed control animals and bottom, the average of 2 P. murina exposed animals (except concanavalin A, n = 1) or results for 1 unexposed control animal. The dashed line in each panel indicates the lower limit of detection; the error bars indicate the standard deviation. Unpaired t tests were used to compare the results for exposed animals to control (unexposed) animals. Statistical significance is indicated by the following symbols: *, p ≤ 0.05; ‡, p ≤ 0.01; †, p ≤ 0.001. Statistical significance was not calculated for the bottom panels due to the small number of animals. Although the results for MCP-3 (top panel) did not reach statistical significance (p = 0.054), all 3 animals had elevated MCP-3 levels in response to crude Pneumocystis antigen, and both animals in the bottom panel showed elevated levels to both crude Pneumocystis antigen and native Msg. In the top panels, error bars are not shown for the results that are below the lower limit of detection, since results for all animals in each group were below that value. In the bottom panels, error bars are not shown for the single unexposed animal.