Interleukin-15 receptor beta (IL-2/IL-15Rβ (also known as IL-2Rβ; gene symbol IL2RB))

The **Interleukin-15 receptor beta** (IL-2/IL-15Rβ, also known as IL2RB or CD122) is a key subunit of the receptors for both interleukin-15 and interleukin-2. It is a type I cytokine receptor found on the surface of lymphocytes, including T cells and NK cells, and is essential for mediating the biological effects of IL-15 and IL-2, such as cell proliferation, activation, and survival of immune cells[1][4][6]. The full high-affinity IL-15 receptor consists of three chains: IL-15Rα (specific for IL-15), IL-2/IL-15Rβ, and the common gamma (γc) chain. The β and γc subunits are shared with the IL-2 receptor, while the α chain is unique for each cytokine. The beta chain is critical for signal transduction, activating the JAK1 and JAK3 kinases and STAT5/STAT3 pathways, which promote immune cell growth and function[1][7][9]. Dysregulated IL-15 receptor signaling is implicated in autoimmune disease, cancer, and inflammatory conditions, making it an important therapeutic target in immunology[6][7][9]. Sometimes “IL-15 receptor” is used to refer to the heterotrimeric complex (α, β, γc), while “IL-15 receptor beta” refers specifically to the beta subunit, which mediates signal transduction in concert with γc[1][6][9]. Experimental drugs mainly target the α chain or the full receptor complex to block IL-15 signaling, but antibodies against IL-2/15Rβ have also been developed for clinical investigation[10].

Other names

IL-2 receptor subunit betaIL-2/15 receptor beta chainIL2RBCD122

Antagonism/blockade of cytokine (IL-15, IL-2) binding Inhibition of downstream JAK/STAT signaling Modulation of T cell and NK cell responses