Fig. 2. Dual prophylactic vaccination with IL-4-K and IL-13-K prevents elevated IgE levels and lung mast cell numbers after HDM challenges.

a–c Levels of total IgE (a), HDM-specific IgE (b), and HDM-specific IgG (c) 24 h after the last HDM challenge. Results show values from individual mice with bars indicating mean ± SEM from n = 12 mice (PBS/PBS group), n = 16 mice (CRM₁₉₇/PBS group), n = 19 mice (IL-13-K/HDM group), or n = 20 mice (IL-4-K and IL-4-K + IL-13-K groups) pooled from two independent experiments. d Representative lung sections stained with toluidine blue, demonstrating mast cells (arrows) 24 h after the last HDM challenge. Insert represent magnifications of the dashed areas. e Quantification of toluidine blue-positive lung mast cells. Results show values from individual mice with bars indicating mean ± SEM from n = 8 mice. f Representative lung sections stained with avidin (which stains mast cells, red), anti-IgE (green), and DAPI (blue) 24 h after the last HDM challenge. g Quantification of IgE levels in avidin-positive lung mast cells. Results show values from individual avidin-positive mast cells analyzed in ear skin sections from n = 4 mice/group with bars indicating means ± SEMs. P values were calculated using two-tailed Mann–Whitney U test vs. PBS/PBS group (in a), CRM₁₉₇/PBS group (in b, e, and g) or vs. indicated groups. Source data are provided in the Source data file.