Figure 7.

ILC3‐derived IL‐17A, but not IL‐22, could promote the UPEC elimination through recruiting the neutrophils. A) 8 weeks‐old WT female mice were intraperitoneally injected with anti‐IL‐22 mAb or mouse IgG1 (200µg per mouse each time) before UPEC infection. The UPEC burdens in the whole bladder tissue at 18 h after infection are shown (n = 6 mice). B) 8 weeks‐old Rorc ^cre Id2 ^fl/fl female mice were intravenously injected with IL‐22‐Fc (500ng), and control Id2 ^fl/fl and Rorc ^cre Id2 ^fl/fl mice were injected with PBS, then infected with UPEC. The UPEC burdens in the whole bladder at 18 h after infection are shown (n = 5 mice). C) The mRNA expression of Il22r and Il17ra in the naive bladder, UPEC‐infected bladder, and gut are shown (n = 5 mice). D) 8 weeks‐old Rorc ^cre Id2 ^fl/fl female mice were intravenously injected with recombinant IL‐17A (500ng), and control Id2 ^fl/fl and Rorc ^cre Id2 ^fl/fl mice were injected with PBS, then infected them by UPEC. The UPEC burdens in the whole bladder tissue at 18 h after infection are shown (n = 6–7 mice). 8 weeks‐old Id2 ^fl/fl, Rorc ^cre Id2 ^fl/fl, and IL‐17A‐injected Rorc ^cre Id2 ^fl/fl female mice were infected by UPEC and compared with uninfected Id2 ^fl/fl mice. The bladders at 4h post‐treatment were isolated and analyzed by flow cytometry and Real‐time qPCR. E) Representative plots show the gated neutrophils (CD45⁺Ly6c^medLy6g⁺ cells). F) The percentages and absolute counts of neutrophils in the whole bladder are shown (n = 5 mice). G) The mRNA expression of the indicated chemokines is shown (n = 6–10 mice). Data are representative of three independent experiments. Error bars represent the mean ± SEM. Unpaired two‐tails student's t‐test (A), Kruskal–Wallis test (B, C), and One‐way ANOVA test (D, F, G) were used for statistical analysis, *p<0.05, **p<0.01; ns, no significant difference.