FIG. 3.
Effects of anti-IFN-γ antibodies on suppression of the growth of L. pneumophila in BM macrophages treated with IL-12 plus IL-18. Cytokines (20 ng/ml) were added to the wells of L. pneumophila-infected BM macrophages (105 cells) at 24 h after infection (n = 5). Several concentrations of anti-IFN-γ antibodies were added simultaneously with IL-12 and IL-18. Bacterial numbers in the wells were determined on day 7 after infection. The results represent means ± standard deviations for five wells. Similar results were obtained in at least two independent experiments. An asterisk indicates a P value of <0.05 in a comparison with the group receiving IL-12 plus IL-18 but not antibodies.