Interleukin‑15 receptor alpha complex (IL-15Rα complex)

The Interleukin‑15 receptor alpha complex (IL-15Rα complex) is a multi-subunit cytokine receptor complex that binds interleukin-15 (IL-15), facilitating its high-affinity presentation to immune cells. This complex typically includes three subunits: IL-15Rα, IL-2Rβ (CD122), and the common gamma chain (γc, CD132). IL-15Rα imparts unique high-affinity binding and is widely expressed on immune and non-immune cells, enabling "trans-presentation" of IL-15 – a mechanism where IL-15 pre-bound to IL-15Rα is presented to effector cells expressing the shared β and γ chains, thereby initiating signaling cascades that stimulate immune cell survival, proliferation, and activation via JAK/STAT, PI3K/Akt, and MAPK pathways. It has essential roles in homeostatic and inflammatory immune regulation, is implicated in anti-tumor immunity, infectious disease, and autoimmunity, and is the focus of multiple therapeutic agents and clinical trials.

Other names

Interleukin-15:IL-15 receptor alpha complexIL-15–IL-15Rα complexIL15RA complexIL-15:IL-15Rα complex

Drugs targeting the IL-15–IL-15Rα complex mimic or enhance trans-presentation, leading to heightened T cell and NK cell proliferation and activation. Superagonist complexes increase cytokine potency for immune stimulation.