IL-2Rβ (D4X3H) Rabbit mAb #46307

Interleukin-2 (IL-2) is a T cell stimulatory cytokine best known for inducing T cell proliferation and NK cell proliferation and activation (1,2). IL-2 also promotes peripheral development of regulatory T cells (Tregs) (3,4). Conversely, IL-2 is involved in the activation-induced cell death (AICD) that is observed post T cell expansion by increasing levels of Fas on CD4⁺ T cells (5). The effects of IL-2 are mediated through a trimeric receptor complex consisting of IL-2Rα, IL-2Rβ, and the common gamma chain, γc (1,2). IL-2Rα binds exclusively to IL-2 with low affinity and increases the binding affinity of the whole receptor complex including IL-2Rβ and γc subunits. IL-15 also binds to IL-2Rβ (1,2). γc is used by other cytokines, including IL-4, IL-7, IL-9, IL-15, and IL-21 (1,2). Binding of IL-2 initiates signaling cascades involving Jak1, Jak3, Stat5, and the PI3K/Akt pathways (1,2).

IL-2Rβ, also known as CD122, is a type I transmembrane protein that is expressed by natural killer cells and certain subsets of T cells in the periphery (6). IL-2Rβ surface expression is upregulated following antigen-induced activation. A heteromeric complex composed of IL-2Rβ and γc forms the intermediate affinity IL-2 receptor whereas a complex comprised of all three chains forms the high affinity receptor. Signaling through IL-2Rβ is mediated by Jak1 (7), which phosphorylates numerous tyrosine residues in the cytoplasmic tail to promote the recruitment of the adaptor Shc to IL-2Rβ and enhance IL-2 receptor signaling (8, 9).