High-affinity interleukin-2 receptor (High-affinity IL-2R)

The high-affinity interleukin-2 receptor is a heterotrimeric cell surface receptor composed of three subunits: alpha (CD25, IL-2Rα), beta (CD122, IL-2Rβ), and common gamma (CD132, IL-2Rγ, γc)[1][2][4][6]. This receptor binds the cytokine interleukin-2 (IL-2) and mediates its potent immunoregulatory and trophic effects, primarily in T lymphocytes[3][7]. The high-affinity form is assembled stepwise after antigenic stimulation, with the inducible CD25 subunit capturing IL-2, and the beta and gamma chains mediating intracellular signaling through associated kinases (Jak1, Jak3), activating pathways such as JAK-STAT, MAPK, and PI3K[3][7][9]. This receptor complex plays essential roles in T cell clonal expansion, differentiation, and survival, as well as in the generation and function of regulatory T cells. Dysregulation or therapeutic targeting of the high-affinity IL-2 receptor is relevant in transplant rejection, autoimmunity, and cancer immunotherapy[3][7].

Other names

Interleukin-2 receptorIL-2 receptorIL-2RTrimeric IL-2 receptorCD25/CD122/CD132 complex

Monoclonal antibodies block or deplete CD25 (IL-2Rα) to inhibit T cell activation Recombinant IL-2 acts as an agonist to stimulate the receptor and downstream signaling