human IL-15 ELISA kit (48 Wells)

Interleukin 15 (IL-15) is a 14 kDa cytokine that is structurally and functionally related to IL- 2(1-3). Mature human IL-15 shares 70% amino acid sequence identity with mouse and rat IL-15. Alternate splicing generates isoforms of IL-15 with either a long or short signal peptide (LSP or SSP), and the SSP isoform is retained intracellularly (4). IL-15 associates with IL-15 R? in the endoplasmic reticulum, and this complex is expressed on the cell surface (5, 6). The dominant mechanism of IL-15 action is known as transpresentation in which IL-15 and IL-15 R? are coordinately expressed on the surface of one cell and interact with complexes of IL-2 R?/?c on adjacent cells (7). This enables cells to respond to IL-15 even if they do not express IL-15 R? (6, 8). Consistent with its shared use of IL-2 receptor subunits, IL-15 induces IL-2-like effects in lymphocyte development and homeostasis (3). It is particularly important for the maintenance and activation of NK cells and CD8+ memory T cells (3). IL-15 also exerts pleiotropic effects on other hematopoietic cells and nonimmune cells (2). Ligation of membraneassociated IL-15/IL-15R? complexes induces reverse signaling that promotes cellular adhesion, tyrosine phosphorylation of intracellular proteins, and cytokine secretion by the IL-15/IL-15R? expressing cells (9, 10).

For the quantitative determination of human interleukin 15 (IL-15) concentrations in cell culture supernates, serum, and plasma.

Principle of the assay: This assay employs the quantitative sandwich enzyme immunoassay technique. A monoclonal antibody specific for IL-15 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any IL-15 present is bound by the immobilized antibody. Following incubation unbound samples are removed during a wash step, and then a detection antibody specific for IL-15 is added to the wells and binds to the combination of capture antibody- IL-15 in sample. Following a wash to remove any unbound combination, and enzyme conjugate is added to the wells. Following incubation and wash steps a substrate is added. A coloured product is formed in proportion to the amount of IL-15 present in the sample. The reaction is terminated by addition of acid and absorbance is measured at 450nm. A standard curve is prepared from seven IL-15 standard dilutions and IL-15 sample concentration determined.