IL-4 facilitates airway sensitization by acting on hematopoetic and structural cells.

<p>Chimeric mice, expressing STAT6 in either SC, HC, neither or both were sensitized intranasally with 5 µg OVA in combination with 1 µg IL-4 for three consecutive days and challenged with 25 µg OVA for four days. Animals sensitized with OVA only served as controls. Analyses were performed two days after last challenge. A: BAL cell differentiation of STAT6 chimeric mice. B–E: BAL cell distribution of STAT6 chimeric mice, B = eosinophils, C = lymphocytes, D = macrophages, E = neutrophils. F: OVA-specific cytokine expression in lung draining lymph nodes from STAT6 chimeric mice on day 3 of culture. G: OVA-specific IgE in serum of STAT6 chimeric mice. SC = structural compartment. HC = hematopoetic compartment. LU = laboratory units. *p<0.05 by Mann-Whitney-U-test compared to all other variables. Representative experiments of n = 2–8 experiments.