FIG. 3.

Immunomodulatory effect of endogenous IL-18 and IL-12 on intrapulmonary IFN-γ during replicative L. pneumophila lung infection. A/J mice were administered anti-IL-18R MAb, anti-IL-12 MAb, or both MAbs prior to intratracheal inoculation with L. pneumophila. At specific time points p.i., mice were euthanatized, and lungs were excised, homogenized, and filtered. Intrapulmonary levels of IFN-γ were quantified in filtered lung homogenates by ELISA. Mice were treated with control antibody (IgG2a) (solid bars), anti-IL-12 MAb (shaded bars), anti-IL-18RmAB (hatched bars), anti-IL-12 MAb and anti-IL-18R MAb (horizontally striped bars). Results represent means ± standard errors of the means for five animals per treatment group. ∗, P < 0.05 (considered significant).