Interleukin-15 receptor beta-gamma complex (IL-15Rβγ complex)

The **interleukin-15 receptor beta-gamma complex** is a heterodimeric cell surface receptor composed of the IL-2/15 receptor beta chain (CD122) and the common gamma chain (γc, CD132), both of which are shared with the IL-2 receptor and other cytokine receptors in the common gamma chain family[2][4][5][7]. This complex is essential for the signal transduction of interleukin-15 (IL-15), a cytokine with critical roles in the development, survival, and activation of NK cells, CD8+ memory T cells, and other lymphocytes[2][4]. Unlike IL-2, whose alpha-chain is expressed on the same cell as beta and gamma, IL-15 signaling uniquely relies on the trans-presentation mechanism: IL-15 is presented bound to its high-affinity alpha receptor (IL-15Rα) on one cell and then activates the beta-gamma signaling complex on neighboring cells[5][7][10]. Engagement of the IL-15Rβγ complex leads to the activation of Janus kinases (JAK1 and JAK3) and subsequent phosphorylation of STAT3 and STAT5, resulting in transcription of genes that support cell proliferation, survival, and cytotoxic function[2][4][7]. This pathway is implicated in immune defense, tumor surveillance, and various immune-mediated diseases, making the IL-15Rβγ complex a promising target for immunotherapy and immune modulation[4][8].

Other names

IL-15 receptor beta-gamma complexIL-2/15 receptor beta-gamma complexCD122/γc complex (CD122 is IL-2Rβ, γc is the common gamma chain)

Activation of JAK1/3 and downstream STAT3/STAT5 signaling by IL-15 engagement[2][4][7] Promotion of cytotoxic lymphocyte survival, proliferation, and function via signal transduction Induction of anti-apoptotic and pro-proliferative gene expression in target cells