Interleukin-2 receptor, intermediate-affinity (IL-2R (intermediate-affinity))

The **interleukin-2 receptor, intermediate-affinity** (IL-2Rβγ or CD122/CD132 dimer) is a plasma membrane receptor complex consisting of the IL-2 receptor β chain (CD122) and the common gamma chain (CD132). Absent the α chain (CD25), this dimer binds IL-2 with intermediate affinity and is primarily expressed on natural killer (NK) cells, memory CD8+ and CD4+ T cells. The receptor is a member of the type I cytokine receptor family. Upon IL-2 engagement, the intermediate-affinity receptor initiates intracellular signaling via JAK1 and JAK3 kinases, leading to activation of the JAK-STAT, PI3K/AKT, and MAPK pathways, driving lymphocyte proliferation, survival, and effector function. This mechanism is therapeutically relevant in immuno-oncology, autoimmune diseases, and infection. The βγ dimer complex is also a drug target for engineered cytokines, agonist antibodies, and immune modulators aiming to expand or modulate the activity of NK and memory T cells without triggering regulatory T cells, which require the high-affinity (αβγ) receptor[2][3][4][5][6][7].

Other names

IL-2Rβγ complexIL-2 receptor beta-gamma dimerCD122/CD132 (dimer)intermediate-affinity IL-2 receptor

IL-2 pathway agonism: stimulates lymphocyte (NK, memory T) proliferation by triggering JAK-STAT, PI3K/AKT, and MAPK signaling upon IL-2 binding to βγ dimer[2][3][5][6]. Antibody blockade: certain monoclonal antibodies can block the β or γ chains, inhibiting IL-2-mediated signaling[2][9].