Interleukin-15 receptor subunit alpha–Interleukin-15 complex (IL-15Rα–IL-15 complex)

The target "Interleukin-15 receptor subunit alpha–Interleukin–15 complex" is an accurate molecular entity, referring to the high-affinity cell surface complex between the receptor subunit (IL-15Rα) and its ligand (IL-15). However, structured drug-target databases and the literature more commonly treat IL-15 receptor subunit alpha (IL-15Rα) as the primary molecular target, with the complex itself noted in mechanism or pharmacology sections rather than as the canonical target entry. Researchers may refer to the "IL-15/IL-15Rα complex" when describing the unique biology of "trans-presentation" (where a presenting cell displays IL-15 bound to IL-15Rα to neighboring cells), but for structured data, the canonical target entry is "Interleukin-15 receptor subunit alpha" or, for the full functional unit, "Interleukin-15 receptor." Thus, listing the complex as a standalone target is an uncommon practice, but not incorrect if used with precision. The Interleukin-15 receptor subunit alpha–Interleukin-15 complex is a high-affinity cell surface complex consisting of the IL-15 receptor alpha (IL-15Rα) and its cytokine ligand, interleukin-15 (IL-15). This complex is uniquely capable of “trans-presentation”, in which one cell type (e.g., dendritic cells) presents IL-15 bound to IL-15Rα on its surface to neighboring lymphocytes (usually NK or CD8+ T cells), thereby delivering proliferation and survival signals that are critical for normal immune function and host defense. The biology of this complex is distinct from classic cytokine signaling, as it enables spatially and temporally restricted activation of target immune cells. The IL-15–IL-15Rα axis is implicated in inflammatory diseases, certain cancers, and is an emerging target for immunotherapies, both as an agonist (to boost immune responses in cancer) and as an antagonist (to limit inflammation or autoimmunity). Drugs may target the ligand, receptor, entire complex, or exploit the biology of the complex for enhanced therapeutic effect. Caveats: The complex itself is sometimes considered a drug or biological agent (e.g., engineered fusion proteins) rather than a classic “receptor target”; pharmacological targeting is commonly at the level of IL-15, IL-15Rα, or the functional complex. Full structure–function and drug interaction data may require focused literature review for the specific complex form in use. For structured database mapping, it may be preferable to attribute most structured fields to “Interleukin-15 receptor subunit alpha (IL-15Rα)” and list the complex as a mechanism or context as appropriate.

Other names

IL-15Rα–IL-15 complexIL15–IL15RA complexInterleukin-15/IL-15R alpha complexInterleukin-15–Interleukin-15 receptor alpha complexIL-15 presented by IL-15Rα

Inhibition of IL-15 signaling by blocking IL-15 or IL-15Rα; Activation or augmentation of immune cell activity by providing stabilized IL-15–IL-15Rα complex (“superagonist” approaches for cancer immunotherapy); Prevention of trans-presentation function to modulate immune responses.