Interleukin-2 receptor subunit beta and cytokine receptor common subunit gamma heterodimer (IL-2Rβγ)

The Interleukin-2 receptor subunit beta (CD122) and cytokine receptor common subunit gamma (CD132) form a heterodimeric complex that functions as the intermediate-affinity receptor for interleukin-2 (IL-2) and the primary signaling component for interleukin-15 (IL-15) (UniProt P14784, P31785). This heterodimer is constitutively expressed on natural killer (NK) cells and memory CD8+ T cells, whereas the high-affinity trimeric receptor, which includes the alpha subunit (CD25), is predominantly found on regulatory T cells (Tregs) (PubMed: 22391954). In oncology, this complex is a major therapeutic target for "biased" IL-2 formulations and mimetics designed to selectively activate cytotoxic immune cells while avoiding the immunosuppressive effects and toxicities, such as vascular leak syndrome, associated with CD25 binding (PubMed: 29324334). Upon activation, the βγ heterodimer initiates intracellular signaling through the recruitment of Janus kinases (JAK1 and JAK3) and the subsequent phosphorylation of STAT5, promoting the expansion and effector function of lymphocytes (PubMed: 10485649). Modern drug development, including agents like bempegaldesleukin and NL-201, focuses on engineered cytokines that stabilize or specifically target this heterodimer to treat solid tumors and hematologic malignancies (NCI Drug Dictionary). Additionally, the common gamma chain is a shared component among several cytokine receptors, making this specific heterodimer a critical node in immune signaling and a target for modulating autoimmune responses.

Other names

CD122/CD132 complexIntermediate-affinity interleukin-2 receptorIL-2R beta/gammaIL-15 receptor signaling complexIL2RB/IL2RG heterodimer

Agonism of the IL-2Rβγ complex triggers the JAK/STAT signaling pathway; specifically, the cytoplasmic domains of IL-2Rβ and γc recruit JAK1 and JAK3, respectively, leading to the phosphorylation of STAT5 and the activation of the PI3K/Akt and MAPK pathways (PubMed: 10485649, 22391954).