Mouse IL-15R/IL-15 Complex ELISA Ready-SET-Go!®

Description: This mouse Interleukin-15/Interleukin-15 Receptor (IL-15/IL-15R) ELISA set contains all of the necessary reagents for the performance of quantitative enzyme-linked immunosorbent assays. It has been optimized for the accurate and precise measurement of IL-15/IL-15R protein levels from serum, plasma, and tissue culture supernatant samples. Recombinant mouse IL-15 has a cross-reactivity of 2% in this assay when spiked in excess (100 ng/ml). The specificity of this ELISA has been confirmed with bone-marrow derived dendritic cells from IL-15 knock-out mice; Tissue culture supernatant from these cells following lipopolysaccharide (LPS) stimulation was negative for the presence of IL-15/IL-15R complex while wild type animals reveal more than 40pg/ml.

Interleukin-15 (IL-15) is a 14 kDa proinflammatory protein that has been shown to play a role in the activation of neutrophils, dendritic cells, and macrophages, and is essential to the development and survival of NK cells and CD8 T-cells. IL-15 activates Jak/Stat pathways by signaling through a heterotrimeric receptor. Two of the subunits of this receptor, β and γ, are shared with the IL-2 receptor, while the α subunit is unique to IL-15.

Despite the expression of IL-15 mRNA in many cell types, the secreted protein is rarely detectable in biological samples. Recent research suggests that IL-15 is retained inside the cell and is only secreted in complex with its unique receptor, IL-15Rα. This chaperoning is required from the ER to Golgi through to secretion. The cytokine/receptor complex may stay bound to the cell surface, where it can be trans-presented to cells expressing the βγ subunits of the receptor, or may be secreted in a soluble form that lacks the transmembrane domain of the receptor. The soluble IL-15/IL-15R complex is produced by mouse dendritic cells, fibroblasts, and macrophages, and demonstrates a 10-100-fold increase in agonistic activity over IL-15 alone.

References: Duitman EH, Orinska Z, Bulanova E, Paus R, Bulfone-Paus S. How a cytokine is chaperoned through the secretory pathway by complexing with its own receptor: lessons from interleukin-15 (IL-15)/IL-15 receptor alpha. Mol Cell Biol. 2008 Aug;28(15):4851-61

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Rubinstein M, Kovar M, Purton JF, Cho JH, Boyman O, Surh CD, Sprent J. Converting IL-15 to a superagonist by binding to soluble IL-15Ralpha. Proc Acad Nat Sci USA. 2006 Jun 13;103(24):9166-71

Zhang H and Meadows GG. Exogenous IL-15 in combination with IL-15R alpha rescues natural killer cells from apoptosis induced by chronic alcohol consumption. Alcohol Clin Exp Res. 2009 Mar;33(3):419-27