Figure 8.

CD40 promotes early IFN- γ production in the LALN of mice infected with C. neoformans. Leukocytes isolated from the LALN of CD40^+/+ mice and CD40^−/− mice at 2 weeks postintratracheal infection with 10⁴ C. neoformans were cultured overnight in vitro at 5 × 10⁶ cells/ml in the presence of 1 × 10⁷ heat-killed C. neoformans/ml. Culture supernatants were analyzed for IFN- γ and IL-5 by ELISA as described in Materials and Methods. Data pooled from two separate matched experiments are expressed as the mean cytokine concentration (nanograms per milliliter) ± SEM; n = 8–9 mice per strain at each time point; *P < 0.05 for comparison between CD40^+/+ mice (black bars) versus CD40^−/− mice (gray bars).