Fig. 2.

DTH in single-housed Mavs^−/− mice is characterized by increased edema that is inhibited by antibiotics treatment. (A) Ear swelling was measured 8 and 24 h after challenge (WT mice: n = 27; Mavs^−/− mice: n = 33). Ear swellings measured at 8 and 24 h were pooled. The peak of the response can occur 24 or 48 h after challenge (SI Appendix, Fig. S2). Results are mean values ± SDs (pool of three representative experiments among eight). (B) Analysis of adaptive and innate immune cell infiltration at the challenged site. Ears from WT (n = 10) and Mavs^−/− (n = 11) mice were harvested at the peak of the response (24 h postchallenge), and immune cell recruitment was analyzed by flow cytometry. Results are mean values ± SDs of one representative experiment of two. (C) IL-1β and IFNγ cytokines were measured in ear supernatant 24 h postchallenge by ELISA. Data are mean ± SEMs of triplicate technical values (two experiments with n = 5). (D) Histology of Mavs^−/− and WT ears harvested 24 h postchallenge. (E) WT (n = 22) and Mavs^−/− (n = 19) mice were given ABX in the drinking water for 4 wk before and during the DTH experiment (control mice without ABX: WT n = 19, Mavs^−/− n = 16). The antibiotic mixture was composed of 1 g/L each of ampicillin, neomycin sulfate, and metronidazole and 0.5 g/L of vancomycin hydrochloride. Ear swelling was measured 24 h postchallenge. Data are mean values ± SDs of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, and ns, not significant, as determined by nonparametric ANOVA (Kruskal–Wallis test) followed by the pairwise Dunn’s multiple comparison test (A) and Mann–Whitney U nonparametric test (B–E).