CD4⁺ and CD8⁺ T cells and IFN-γ are essential for surviving virulent <i>Ft</i> infection in outbred SW mice.

SW female mice were immunized and challenged as described in Fig 2. Vaccinated mice were treated with anti-CD4+, anti-CD8+, or isotype control Ab on days -4, -1, 2, 5, and 8 relative to Ft SchuS4 infection and monitored for survival (A). Alternatively, mice were treated with anti-IFN-γ, anti-IL-17A, or isotype control Ab on days -1, 1, 3, and 5 relative to Ft SchuS4 infection and monitored for survival (B). Ft SchuS4 burdens in the lungs and spleens of naïve or vaccinated SW mice treated with depleting Ab specific for IFN-γ or IL-17A (n = 3 mice per group, day 5 post 40 CFU Ft SchuS4 in challenge) (C and D). Panels A & B represents combined results from two independent experiments with a total of 10 mice/ group, panel C is representative of two independent experiments. *p p p < 0.001.