Rabbit Polyclonal antibody to IL~2RB/CD122

Interleukin~2 (IL~2) is a T cell stimulatory cytokine best known for inducing T cell proliferation and NK cell proliferation and activation. IL~2 also promotes peripheral development of regulatory T cells (Tregs). 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. The effects of IL~2 are mediated through a trimeric receptor complex consisting of IL~2Rα, IL~2Rβ, and the common gamma chain, γc. 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. γc is used by other cytokines, including IL~4, IL~7, IL~9, IL~15, and IL~21. Binding of IL~2 initiates signaling cascades involving Jak1, Jak3, Stat5, and the PI3K/Akt pathways.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. 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, 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.