Interleukin-5 Receptor Alpha (IL5RA)

Interleukin-5 receptor alpha (IL5RA), also known as CD125, is a subunit of the interleukin-5 receptor complex. It is encoded by the IL5RA gene in humans and plays a critical role in mediating the biological effects of interleukin-5 (IL-5), particularly in eosinophil biology and allergic inflammation. The IL-5 receptor is a heterodimer composed of an α subunit (IL-5Rα or CD125) and a β common subunit (βc or CD131). Upon ligand binding, signal transduction involves activation of intracellular kinases such as JAK2 and LYN, leading to downstream phosphorylation events including STAT family members that drive gene expression changes associated with eosinophil proliferation, survival, migration, and activation. Dysregulation or overactivation contributes significantly to diseases characterized by eosinophilia—such as asthma—and thus makes it an important therapeutic target.

Other names

CD125IL5R alpha subunitIL-5Rα

Neutralizing antibodies targeting either the receptor or its ligand