MyD88 is responsible for the early induction of Th1-related cytokines after N. caninum infection. The presence of IL-12p40, IFN-γ, and IL-10 was evaluated by ELISA in the peritoneal exudate and serum samples of uninfected, and infected WT and MyD88^−/− mice at 3, 7, and 10 days p.i. (n = 3 mice/group/date). Data are representative of two independent experiments. * Indicates significant statistical differences (mean ± SEM, p < 0.05).