Interleukin-2 receptor (IL-2R) (IL-2R)

The Interleukin-2 receptor (IL-2R) is a multi-subunit protein complex expressed on the surface of immune cells, primarily T-cells and natural killer (NK) cells (UniProt P01589). It is composed of three distinct chains: IL-2Rα (CD25), IL-2Rβ (CD122), and the common gamma chain (γc, CD132), which together form the high-affinity receptor required for robust signal transduction (PMID: 22391954). Signaling through the IL-2R primarily activates the JAK/STAT, PI3K/Akt, and MAPK pathways, which are essential for lymphocyte survival and proliferation (StatPearls, Interleukin-2). The IL-2R system is fundamental to the adaptive immune response, governing the expansion of effector T-cells during infection and the maintenance of regulatory T-cells (Tregs) for self-tolerance (PubMed: 22391954). In oncology, IL-2R is a major therapeutic target where agonists like Aldesleukin are used to enhance anti-tumor immunity in metastatic melanoma and renal cell carcinoma (NIH/NCI). Conversely, IL-2R antagonists such as Basiliximab are used in transplant medicine to prevent acute organ rejection by blocking T-cell activation (PubMed: 10073351). Modern drug development focuses on engineering "biased" IL-2 variants that selectively target specific receptor subunits to maximize therapeutic efficacy while minimizing systemic toxicities like vascular leak syndrome (PMID: 31004302).

Other names

CD25CD122CD132T-cell growth factor receptorIL2RInterleukin-2 receptor subunit alphaInterleukin-2 receptor subunit betaInterleukin-2 receptor subunit gamma

Drugs targeting the IL-2 receptor act as either agonists to stimulate immune cell proliferation and anti-tumor activity or as antagonists to block IL-2 signaling and suppress immune responses in autoimmunity or transplantation.