Der f 31, a novel allergen from Dermatophagoides farinae, activates epithelial cells and enhances lung-resident group 2 innate lymphoid cells

Airway epithelial cell-derived thymic stromal lymphopoietin (TSLP) and IL-33 can enhance lung-resident group 2 innate lymphoid cells (ILC2s), and they play an important role in the development of allergic diseases. This study tests the hypothesis that Der f 31 (Dermatophagoides farinae-31), an allergen, modulates airway epithelial cell functions and increases the frequency of lung ILC2s. Our previous research identified cofilin (Der f 31) as a novel allergen. In this study, we found that recombinant Der f 31 (r-Der f 31) upregulated the expression of co-stimulatory molecules in DCs and promoted Th2-skewed polarization. The levels of TSLP and IL-33 in epithelial cells were upregulated by r-Der f 31 via the activation of Toll-like receptor 2. Furthermore, in in vivo studies, r-Der f 31 induced eosinophil-like airway allergy and increased the number of lung-resident ILC2s. In summary, Der f 31 can modulate the functions of airway epithelial cells and increase levels of lung-resident ILC2s.