TNF and infection: Assessment of Th1 cytokines production by the spleen cells showed that at day 7 post-infection, the levels of IL-12p40 (134±64 pg/mL), TNF-α (402±25 pg/mL), and IFN-γ (527±9 pg/mL) produced by cells from female mice stimulated with paracoccin were significantly (p<0.05) higher than those produced by cells from male mice (132±15 pg/mL, 179±71 pg/mL, and 247±20 pg/mL, respectively (Figure 1A, C, E).