Interleukin-15 (IL-15) is secreted by a variety of cell types including monocytes, macrophages, dendritic and epithelial cells. IL-15 promotes activation and expansion of natural killer (NK), natural killer T (NKT) and CD8+ memory T cells. Unlike IL-2, IL-15 doesn’t impact CD4+ regulatory T cells (Treg) or induce activation-induced cell death (AICD).
Multiple pathways can be activated by IL-15 signaling. In lymphocytes, JAK/STAT signaling begins with JAK1 and JAK3 tyrosine kinase recruitment and activation at the receptor cytoplasmic domains. These kinases recruit and activate STAT3 and 5 with phosphorylated dimer/tetramer translocation to the nucleus for transcriptional activation of a variety of proteins. These pathways impact cell proliferation, anti-apoptotic survival and cytotoxic effector functions.
The IL-15 Bioassay is a bioluminescent cell-based assay designed to measure IL-15 stimulation or inhibition. The IL-15 Bioassay Cells have been engineered to express luc2 in response to IL-15 signaling. When IL-15 binds to IL-15 Bioassay Cells, the receptor transduces intracellular signals resulting in luminescence. The bioluminescent signal is detected and quantified using Bio-Glo™ Luciferase Assay System (Cat.# G7940) and a standard luminometer such as the GloMax® Discover System (Cat.# GM3000).