Mouse interleukin-15 receptor subunit alpha, also known as Il15ra, is a high-affinity receptor for interleukin-15. Il15ra associates as a heterotrimer with the IL-2 receptor beta and gamma subunits (Common gamma chain, or gamma c) to initiate signal transduction. It can signal both in cis and trans where IL15R from one subset of cells presents IL15 to neighboring IL2RG-expressing cells. Il15ra is expressed in special cells including a wide variety of Tand B cells and non-lymphoid cells. Human Il15ra shares 45% amino acid sequence homology with the mouse form of the receptor. Eight isoforms of IL-15 R alpha mRNA have been identified, resulting from alternative splicing events involving different exons.
Interleukin 15 Receptor alpha (IL-15Rα) is a transmembrane glycoprotein that plays a pleiotropic role in immune development and function, including the positive maintenance of lymphocyte homeostasis. IL-15Rα chain can bind soluble IL-15 and “transpresent” cytokine to the cells, allowing them to respond to IL-15. Soluble IL-15Rα can function as a specific high-affinity IL-15 antagonist. The soluble IL-15 IL-15Rα complexes exhibit a strong agonistic activity which is mediated through membrane-bound IL-15 receptor β and γ heterodimers and enables signaling to cells.