Fig. 7. Depletion of IL-17 impairs clearance from the nasal cavity following re-challenge of convalescent mice.
C57BL/6 mice were aerosol infected with B. pertussis and allowed to clear the infection. 3 months later, convalescent mice were re-challenged with B. pertussis. Mice were treated with anti-IL-17A or isotype control from one day before infection until the end of the experiment. Prior to infection and 7 days post challenge, 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 immune cells were analyzed by flow cytometry. CFU counts in lungs (a) and nasal washes (b) of anti-IL-17A treated re-infected convalescent mice. IFN-γ- (c) and IL-17A (d) -producing CD4 TRM cells in lungs and nasal tissue. e Representative dot plots of IL-17A- or IFN-γ-producing CD4 TRM cells on day 7 post re-challenge of anti-IL-17A or isotype treated convalescent mice. f Absolute numbers of neutrophils, CD45 i.v.− tissue-resident neutrophils, and % of CD45 i.v.− cells in total neutrophils in the lungs. g Representative dot plots of total neutrophils (Ly6C+ Ly6G+) in lungs and noses on day 7 post re-challenge of anti-IL-17A treated convalescent mice. h Absolute numbers of neutrophils, CD45 i.v.− tissue-resident neutrophils, and % of CD45 i.v.− cells in total neutrophils in the nasal tissue. Statistical analysis: a, b Two-way ANOVA followed by Sidak’s post-test, ***p < 0.001; c, d, f, h unpaired, two-tailed t-test, *p < 0.05, **p < 0.01, ***p < 0.001; n = 4/group, mean ± SEM.