Interleukin-2 receptor heterotrimer (IL-2Rαβγ)

The Interleukin-2 receptor heterotrimer is a high-affinity transmembrane complex composed of three distinct subunits: IL-2Rα (CD25), IL-2Rβ (CD122), and the common gamma chain (γc, CD132) (UniProt P01589, P14784, P31785). It serves as the primary mediator for Interleukin-2 (IL-2) signaling, which is vital for the growth, survival, and differentiation of T-lymphocytes and Natural Killer (NK) cells (PubMed PMID: 22391954). Upon IL-2 binding, the receptor triggers intracellular signaling cascades, most notably the JAK-STAT, PI3K/Akt, and MAPK pathways (StatPearls, Interleukin-2). This receptor complex plays a dual role in the immune system: it is critical for the expansion of effector T-cells during an active immune response and for the maintenance of regulatory T-cells (Tregs) that prevent autoimmunity (NIH, Gene ID: 3559). In clinical practice, the IL-2 receptor is a major therapeutic target; agonists like recombinant IL-2 are used to stimulate anti-tumor immunity in cancers such as melanoma and renal cell carcinoma, while antagonists like monoclonal antibodies against the alpha subunit are used to prevent organ transplant rejection (PubChem, CID: 16133750). However, systemic activation of this receptor can lead to severe side effects, such as vascular leak syndrome, which occurs when the receptor is activated on vascular endothelial cells (PubMed PMID: 25824306).

Other names

High-affinity IL-2 receptorCD25/CD122/CD132 complexIL-2R alpha-beta-gamma complexInterleukin-2 receptor alpha/beta/gamma

Agonism activates the JAK-STAT, PI3K/Akt, and MAPK pathways to promote lymphocyte proliferation and survival; antagonism blocks IL-2 binding to the alpha subunit to prevent T-cell mediated immune responses (StatPearls, Interleukin-2).