Interleukin-2 receptor, high affinity (IL-2R (high affinity), sometimes just IL-2R)

The high-affinity interleukin-2 receptor is a three-chain complex (IL-2Rα/CD25, IL-2Rβ/CD122, IL-2Rγ/CD132) found on activated T cells and regulatory T cells. It is essential for mediating the effects of IL-2, a cytokine involved in immune cell growth, proliferation, and regulation. Each subunit alone has low or intermediate affinity for IL-2, but all three together produce a high-affinity receptor necessary for robust signaling. This complex signals via the JAK/STAT pathway, primarily activating STAT5 transcription factor, and regulates both effector and regulatory immune responses. The receptor is a focus for immunomodulatory therapies targeting cancer, transplantation, and autoimmune diseases. Safety concerns for therapeutic agents include risks of immune dysregulation, infection, and cytokine-related toxicities[1][3][6][9].

Other names

Interleukin-2 receptor (IL-2R)CD25 (for alpha chain)IL-2Rα (alpha)IL-2Rβ (beta)IL-2Rγ (gamma/c or common gamma chain)Tac antigenp55 (alpha)p75 (beta)CD122 (beta)CD132 (gamma)IL2RAIL2RBIL2RG

Direct blockade of IL-2 binding (antagonism, e.g., anti-CD25 antibodies prevent IL-2 from binding) Receptor-mediated cell depletion (e.g., antibody-dependent cellular cytotoxicity against CD25+ cells) Receptor agonism (e.g., recombinant IL-2 stimulates immune response[6])