Effect of equalizing bacterial loads of WT and ΔPT on IL-17 expression.

<p>(A, B) Bacterial loads in the respiratory tract of mice on the indicated days post-infection with (A) 5×10⁴ CFU of WT (black bars) versus 5×10⁵ CFU of ΔPT (open bars), or (B) 5×10⁵ CFU of WT versus 5×10⁶ CFU of ΔPT (compare to difference in bacterial loads when inoculum doses are equal in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007079#pone-0007079-g001" target="_blank">Fig. 1</a>). (C–E) Fold increases in gene expression (relative to mock-infected mice) of the cytokines IL-17 (C, D) or IFN-γ (E) in lungs of mice on the indicated days post-infection with the lower doses (C) or higher doses (D, E) of WT (black bars) or ΔPT (open bars) strains. <i>n</i> = 4 mice/treatment group. *Significantly different from WT (P<0.05).