TFF2 is necessary for N. brasiliensis–induced IL-33 production from lung epithelial cells and alveolar macrophages. (A) Levels of IL-33 within the BAL fluid of WT and TFF2^−/− mice after N. brasiliensis infection. Means ± SE of four to five mice/group are shown. (B and C) IL33 mRNA levels within EpCAM⁺ (B) or CD11c⁺ cells (C; 10⁶ total cells) sorted from the lungs of naive or N. brasiliensis–infected WT and TFF2^−/− mice with magnetic beads. Means ± SE of four individual mice/group are shown. (D) Gating strategy for the identification of lung epithelia from whole lung tissue as FSC^HiSSC^Med, EpCAM⁺, CD45⁻, and MHC class II⁻ cells. Representative data from a WT mouse at day 3 after infection stained intracellularly with a PE-labeled isotype control IgG. (E and F) Representative dot plots showing intracellular IL-33 staining within WT or TFF2^−/− lung epithelia at the indicated times after N. brasiliensis infection. Numbers indicate the percentage of positive cells. (G) Quantification of the experiment described in E and F that shows the mean ± SE of four individual mice/group. (H) Gating strategy for the identification of alveolar macrophages from whole lung tissue as CD11b⁻, CD11c⁺, LyCG/C⁻, CD317^+/−, and CD103⁻. (I and J) Representative dot plots showing intracellular IL-33 staining within WT or TFF2^−/− alveolar macrophages at the indicated times after N. brasiliensis infection. Numbers indicate the percentage of positive cells. (K) Quantification of the experiment described in I and J that shows the mean ± SE of four individual mice/group. Data are representative of two to four independent experiments for each genotype analyzed per time point (*, P < 0.05; **, P < 0.01).