Interleukin-5

Interleukin-5 (IL-5) is a homodimeric glycoprotein produced by T cell helper type 2 (TH2) cells, mast cells, eosinophils, CD34+ progenitor cells, epithelial cells, natural killer (NK) T cells, and type 2 innate lymphoid cells. The receptor is a heterodimer comprised of IL-5Ra-subunit and the common beta chain (?c) subunit. The IL-5Ra is expressed on all eosinophils. IL-5 is critical for development, survival, and maintenance of B cells and eosinophils. In combination with IL-4 and IL-13, IL-5 plays a critical role in vascular permeability, smooth muscle contractility, and IgE production. Overproduction of IL-5 is involved in various chronic inflammatory conditions, including allergic rhinitis, eosinophilic asthma, hyper-eosinophilic syndrome, eosinophilic esophagitis, and eosinophilic granulomatosis with polyangiitis. The central role of IL-5 in eosinophil biology, its pathological role in many eosinophilic-mediated diseases, and the expression of IL-5Ra on eosinophils, makes it a very attractive therapeutic target. Several neutralizing monoclonal antibodies directed against IL-5 (mepolizumab and reslizumab) and its receptor IL-5Ra (benralizumab) are effective in treating eosinophilic asthma.

Swiss-Prot Accession Number: P05113