IL-13Rα1

Interleukin-13 receptor alpha 1 (IL-13Rα1, CD213a1) is a 120-145 kDa type I transmembrane glycoprotein of the hematopoietin receptor family that serves as the low-affinity primary binding chain for IL-13. Although IL-13Rα1 alone binds IL-13 weakly, its pairing with IL-4Rα creates the high-affinity type II IL-4/IL-13 receptor, which transduces signals for both IL-13 and IL-4 via JAK1/TYK2-mediated STAT6, IRS-2 and PI3K activation. The receptor is abundantly expressed on non-hematopoietic cells-airway and intestinal epithelium, smooth muscle, fibroblasts and keratinocytes-which explains why IL-13 predominantly evokes tissue remodeling rather than leukocyte activation. IL-13Rα1-mediated signaling drives allergen-induced airway hyperresponsiveness, mucus metaplasia, IgE synthesis, eotaxin production and fibrosis. Dual inhibition of IL-4/IL-13 through this receptor axis (dupilumab targets IL-4Rα) has transformed the treatment of atopic dermatitis, asthma and chronic rhinosinusitis with nasal polyps.