Description: The eBioJM7A4 monoclonal antibody reacts with the IL-15 receptor alpha chain (IL-15Rα). IL-15 and IL-2 are cytokines with overlapping, but distinct, biologic effects. Their receptors share 2 subunits, the IL2R-β and -γ chains, which are essential for signal transduction. The IL-15R-α receptor is structurally related to IL-2R-α. However, the IL-15Rα alone binds IL-15 with a 1,000-fold higher affinity than that seen with IL-2R-α and IL-2. In the human, 3 differentially spliced human IL15R-α variants that are all capable of high affinity binding of IL-15 have been isolated. The cytoplasmic domain of IL15R-α, like that of IL2R-α, is dispensable for mitogenic signaling, suggesting that the primary role of the alpha chains is to confer high affinity binding. At high concentrations, IL-15, like IL-2, is able to signal through a complex of IL2R-β and IL2R-γ in the absence of the alpha subunit.