(A) Female and male mice were infected with 1 × 10⁷ CFU of UPEC strain UTI89-RFP-kan^R and bladders analyzed by flow cytometry at 24 hours PI. Graphs show (A) the number of CD3⁺CD4⁺ T cells, CD3^–NK1.1⁺ NK cells, γδ T cells, and CD4⁺ ILC3s (CD90⁺CD25⁺CD4⁺CD3^–NK1.1^–MHC II^–CD11b^–) in bladders. (B) Female mice were implanted with empty tubing (Mock) or slow-release tubing containing testosterone (T tube) and allowed to recover 1 week before infection with 1 × 10⁷ CFU UPEC strain UTI89-RFP-kan^R. Graphs show the number of CD3⁺CD4⁺ T cells, CD3^–NK1.1⁺ NK cells, γδ T cells, and CD4⁺ ILC3s (CD90⁺CD25⁺CD4⁺CD3^–NK1.1^–MHC II^–CD11b^–) in bladders. (C–E) Graphs show the number of infected female mice, determined by urine sampling, over time in (C) wild-type or RAG2^–/–γc mice, (D) mice treated with isotype or NK1.1-depleting antibody, (E) mice treated with IL-17–neutralizing antibody. (A and B) Data are pooled from 2–3 experiments, n = 4–5/group in each experiment. Each dot is 1 mouse, red dots depict female mice and blue dots are male mice, and lines are medians. In C–E, graphs are representative experiments, n = 6–12 mice per experiment, 2–3 experiments each. In A, *P < 0.05, **P < 0.01 by Kruskal-Wallis test comparing female naive with male naive, female naive with female infected, male naive with male infected, and female infected with male infected, with Dunn’s post hoc test to correct for multiple comparisons. In B, Mann-Whitney test was used with correction for multiple testing by the Holm–Bonferroni method; all P < 0.05 had q < 0.05.