Fig. 7: The role of TLR4 in maintaining trained immunity of ILC2s in the mouse type 2 inflammatory model.

A Experimental protocol employing HDM-sensitized Tlr4^⁻/⁻ mice. i.n., intranasal administration; HDM, house dust mite. B, C Representative contour plots analysis of total ILC2s (B) and IL-13⁺ILC2s (C). D Representative image of MUC5AC immunohistochemistry staining picture to evaluate mucus. E Percentage of total cells in the bronchoalveolar lavage fluid (BALF), percentage of total ILC2s and IL-13⁺ILC2s in lung tissues, concentration of IL-13 in lung tissues, and the percentage of MUC5AC⁺cells among the epithelial cells of mice (wild-type group, n = 6 mice; Tlr4^⁻/⁻group, n = 5 mice). F Experimental protocol employing HDM-sensitized Rag1^⁻/⁻ mice treated with TLR4 antibody. i.n., intranasal administration; i.p., intraperitoneally injection; HDM, house dust mite; Ab, antibody. G, H Representative contour plots analysis of total ILC2s (G) and IL-13⁺ILC2s (H). I Representative image of MUC5AC immunohistochemistry staining picture to evaluate mucus. J Percentage of total cells in the bronchoalveolar lavage fluid (BALF), percentage of total ILC2s and IL-13⁺ILC2s in lung tissues, concentration of IL-13 in lung tissues, and the percentage of MUC5AC⁺cells among the epithelial cells of mice (control group, n = 6 mice; anti-TLR4 group, n = 6 mice). K Experimental protocol employing Rag2^⁻/⁻Il2rg^⁻/⁻C57BL/6 J mice. i.n., intranasal administration; i.v., tail intravenous injection; i.p., intraperitoneally injection; HDM, house dust mite; Ab, antibody. L–O Representative contour plots analysis of eosinophils in lung tissues (L), representative image of MUC5AC immunohistochemistry staining (M), percentage of total cells in the bronchoalveolar lavage fluid (BALF), eosinophils in lung tissues, the percentage of MUC5AC⁺cells among the epithelial cells of mice (N), and airway hyperreactivity (O) in Rag2^⁻/⁻Il2rg^⁻/⁻C57BL/6 J mice injected with purified TLR4⁺ILC2s from HDM-sensitized wild type C57BL/6 J mice and then treated with TLR4 antibody before the following HDM challenge (n = 5 mice in each group). Each dot indicates one mouse, and bars represent mean ± SEM. Data for E and J were pooled from two independent experiments. Results for N to O were confirmed in two independent experimental replicates, with representative data shown. P-values calculated by a two-tailed unpaired t test.