FIG 1.

(A) The BAL fluid IL-17 level was measured on days 1, 3, and 10 postinoculation with P. aeruginosa (PA)-impregnated agarose beads. *, P ≤ 0.05. The IL-17 level was significantly elevated in Cftr-deficient animals at 24 h postinfection (*, P ≤ 0.05) but was not different between WT and Cftr-deficient animals at 3 or 10 days. (B) Concentration of IL-17 in BAL fluid obtained from CF and WT mice after intratracheal inoculation with P. aeruginosa agar beads at 3 h and days 1 through 4. CF mice (n ≥ 6) had more IL-17 on day 1 (*, P = 0.07) and on day 2 (*, P ≤ 0.05) than noninfected CF and WT mouse controls (n ≥ 6) at the baseline. d, day. (C) Mean BAL fluid IL-17 levels obtained on day 2 after inoculation from CF mice (n = 7) and WT mice (n = 7) are plotted against the number of P. aeruginosa CFU. The BAL fluid IL-17 level was significantly higher in CF mice than uninfected CF mouse controls at the baseline (*, P ≤ 0.05) and WT mice infected with the same dose of P. aeruginosa (*, P ≤ 0.05). At a higher dose of P. aeruginosa, the BAL fluid IL-17 concentration increased in the WT mice but not to a level as high as that in the BAL fluid of CF animals. (D) Both CF mice (n = 6) and WT mice (n = 6) into which freely suspended P. aeruginosa (not embedded in agarose beads) was inoculated intranasally had increased levels of IL-17 production in response to an increase in the dose of P. aeruginosa, with CF mice consistently having higher levels of IL-17 (*, P ≤ 0.05). Both CF and WT mice challenged with 4.9 × 10⁷ CFU/mouse had elevated levels of IL-17, with CF mice having higher levels than WT mice, while the infected WT mice had concentrations significantly elevated relative to those in the uninfected WT mouse controls. Values represent the mean ± SEM of the IL-17 concentration.