WT or Clec4n−/− mice were sensitized with 1 × 104 WT BMDC pulsed with PBS (PBS-DC) or with Df (Df-DC) and challenged with 1 μg Df on days 12 and 14. A. Experimental diagram. B. On day 16, cytospins from BAL fluid were stained and counted. Data are means ± SEM (n = 8-11/Df-DC; n = 3/PBS-DC) combined from 3 independent experiments. C. Histologic analyses of the lung. Lung tissues were fixed with paraformaldehyde and stained with the chloroacetate esterase (CAE) reaction and hematoxylin, periodic acid-Schiff (PAS), or Congo red. Eosinophils are indicated by white arrows in Congo red staining, and mucus is stained in purple in PAS. Images were acquired at 20× (CAE and PAS) and 40× (Congo red) magnifications. D. On day 16, pulmonary mononuclear cells were isolated, stimulated, fixed, and stained for CD4, CD8, and intracellular cytokines, and analyzed by flow cytometry, as in Fig. 1 C&D. Data are means ± SEM (n = 13-15/Df-DC; n = 5/PBS-DC) combined from 3 independent experiments.