Fig. 3. Il17A^−/− mice fail to clear B. pertussis infection in the nasal cavity.

WT and Il17A^−/− mice were aerosol infected with B. pertussis. At different time points, mice were injected i.v. with fluorochrome-labeled CD45 antibody and euthanized 10 min later. Cell suspensions were prepared from lung and nasal tissue and cells were stimulated with sBP and CD49d/CD28 and analyzed by flow cytometry. CFU counts in lungs (a) and nasal washes (b) of WT and Il17A^−/− mice. c B. pertussis-specific IgA and IgG2c in nasal washes and lung homogenates. d Representative dot plots of IL-17A- and IFN-γ-production in CD4 T_RM cells in lung and nose of WT and Il17A^−/− on d 28 post infection. Total number of IL-17A (e) and IFN-γ (f) producing CD4 T_RM in lung and nose. g Representative dot plots of Ly6G and Siglec-F expression in lung and nose cell suspensions of WT and Il17A^−/− mice on d 28 post infection. Cell counts of tissue-resident Siglec-F⁻ (h) and Siglec-F⁺ (i) neutrophils in lungs and nasal tissue. Statistical analysis: a, b, e, f, h, i Two-way ANOVA followed by Sidak’s post-test, c Two-way ANOVA comparing WT and IL-17A^−/− d35 followed by Sidak’s post-test, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, n = 4/group, mean ± SEM.