Interleukin-2 receptor high-affinity heterotrimer (IL-2Rαβγ) (IL-2Rαβγ)

The high-affinity interleukin-2 receptor (IL-2R) is a heterotrimeric protein complex composed of three subunits: alpha (CD25), beta (CD122), and the common gamma chain (CD132) (Source: UniProt P01589, P14784, P31785). This complex is primarily expressed on activated T cells and regulatory T cells (Tregs), where it mediates the potent proliferative and survival signals of the cytokine IL-2 (Source: StatPearls, Interleukin-2). Upon IL-2 binding, the receptor triggers intracellular signaling pathways, most notably the JAK-STAT, PI3K/Akt, and MAPK pathways, which are essential for the expansion of effector T cells and the maintenance of immune tolerance via Tregs (Source: PubMed, PMID: 22391154). In clinical practice, this receptor is a major therapeutic target; monoclonal antibodies like basiliximab block the alpha subunit to prevent organ transplant rejection, while recombinant IL-2 therapies aim to stimulate the immune system in certain cancers (Source: PubChem, CID: 135314782). However, targeting this receptor requires careful management due to risks such as vascular leak syndrome or unintended suppression of regulatory immune cells (Source: NIH, IL-2 Side Effects).

Other names

IL-2RαβγCD25/CD122/CD132 complexHigh-affinity IL-2 receptorInterleukin-2 receptor alpha/beta/gammaIL2R-alpha/beta/gamma

Monoclonal antibodies (e.g., basiliximab) bind to the CD25 subunit to competitively inhibit IL-2 binding, thereby preventing T-cell activation and proliferation (Source: FDA Label, Basiliximab). Agonists like aldesleukin bind the heterotrimeric complex to activate the JAK-STAT pathway, promoting the expansion of cytotoxic T cells and natural killer cells for anti-tumor activity (Source: StatPearls, Aldesleukin).