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

The Interleukin-2 receptor subunit beta and Interleukin-2 receptor subunit gamma heterodimer, often referred to as the intermediate-affinity IL-2 receptor, is a critical signaling complex in the immune system (UniProt P14784, P31785). It is primarily expressed on memory CD8+ T cells and natural killer (NK) cells, where it mediates the proliferative and activating effects of IL-2 through the JAK/STAT, PI3K/Akt, and MAPK pathways (PubMed: 22391154). Unlike the high-affinity heterotrimeric receptor that includes the alpha subunit (CD25), the beta-gamma dimer does not require CD25 for signaling, making it a primary target for biased IL-2 immunotherapies (PubMed: 31048553). These therapies, such as Bempegaldesleukin, aim to selectively activate the beta-gamma complex to boost anti-tumor immunity while avoiding the stimulation of CD25-high regulatory T cells (Tregs), which can suppress the immune response (NCI Drug Dictionary). In oncology, drugs targeting this heterodimer are designed to enhance the expansion of effector immune cells to combat various malignancies. However, therapeutic manipulation of this pathway must be carefully managed to avoid systemic toxicities such as vascular leak syndrome and cytokine release syndrome (PubMed: 29101378). The heterodimer is also involved in the signaling of other cytokines like IL-15, which shares the gamma chain and sometimes the beta chain, complicating the specificity of therapeutic interventions. Overall, the IL-2Rβγ complex represents a high-value target for next-generation immunotherapies seeking to decouple the efficacy and toxicity of IL-2 signaling.

Other names

Intermediate-affinity interleukin-2 receptorCD122/CD132 complexIL-2R beta/gammaIL-2 receptor subunit beta/gamma heterodimerIL-2Rβ/γ

Selective agonism of the intermediate-affinity IL-2 receptor complex to promote the expansion and activation of effector CD8+ T cells and natural killer (NK) cells while minimizing the activation of regulatory T cells (Tregs).