Human Interleukin 4 Receptor (IL4R) Protein

Background

The IL4R gene encodes the interleukin-4 receptor alpha (IL-4Rα) subunit, which plays a critical role in the immune system, especially in the regulation of T-helper cell responses. IL-4Rα serves as the receptor for two important cytokines, interleukin-4 (IL-4) and interleukin-13 (IL-13), both of which influence various aspects of immune and inflammatory responses, including antibody production and the polarization of T-helper cells towards the Th2 phenotype. IL-4R signaling is essential in allergic responses, asthma, and other conditions associated with elevated IgE levels and eosinophilia. IL4Rα exists in both membrane-bound and soluble forms, with the soluble form inhibiting the actions of IL-4 by acting as a decoy receptor. IL4Rα is expressed across several cell types, including T and B lymphocytes, monocytes, macrophages, eosinophils, and endothelial cells. This widespread expression reflects the receptor’s importance in orchestrating responses to pathogens, allergens, and other environmental challenges. Given its central role in modulating immune responses, IL4R has become a target of therapeutic interest, particularly in conditions such as allergic asthma, atopic dermatitis, and certain autoimmune diseases.