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

The Interleukin-2 receptor subunit beta and cytokine receptor common subunit gamma heterodimer (IL-2Rβγ) is a transmembrane receptor complex that mediates the biological effects of Interleukin-2 (IL-2) on specific immune cell subsets (Source: UniProt P14784, P31785). Unlike the high-affinity trimeric receptor (IL-2Rαβγ), the βγ heterodimer possesses intermediate affinity for IL-2 and is predominantly expressed on "resting" effector cells, including memory CD8+ T cells and natural killer (NK) cells (Source: PubMed PMID: 22391954). Binding of IL-2 or its analogs to this heterodimer induces the dimerization of the cytoplasmic domains, activating Janus kinases JAK1 and JAK3, which subsequently phosphorylate STAT5 to drive gene transcription associated with cell proliferation and survival (Source: NIH, "The IL-2 Receptor"). This complex has become a focal point in cancer immunotherapy, where "biased" IL-2 agonists are engineered to selectively bind the βγ heterodimer while avoiding the alpha subunit (CD25) (Source: Journal for ImmunoTherapy of Cancer, 2021). This selectivity is intended to promote the expansion of tumor-killing effector cells without simultaneously stimulating regulatory T cells (Tregs), which can suppress the anti-tumor immune response (Source: Nature Reviews Drug Discovery). Furthermore, avoiding CD25 binding is hypothesized to reduce the incidence of vascular leak syndrome, a severe side effect associated with high-dose IL-2 therapy (Source: PubMed PMID: 31036702). Consequently, this receptor complex plays a pivotal role in modern immunotherapeutic strategies for treating various malignancies and potentially chronic viral infections.

Other names

CD122/CD132 complexIntermediate-affinity interleukin-2 receptorIL-2R beta/gamma heterodimerIL-2Rβγ

Agonism of the IL-2Rβγ complex activates the JAK1/JAK3-STAT5 signaling pathway, promoting the expansion and cytotoxic activity of CD8+ T cells and NK cells.