Interleukin 23 (IL-23) is a member of the IL-12 cytokine family, which consists of IL-12, IL-23, IL-27, IL-35 and IL-39. IL-23 binds and signals through a heterodimeric receptor complex. The IL-23 receptor is found on natural killer cells, macrophages, memory T cells (Th17) and keratinocytes. In response to microbial pathogens and wound healing signals, IL-23 is secreted by activated dendritic cells and macrophages with subsequent neutrophil recruitment. Upon IL-23 binding to Th17 cells, signaling begins with tyrosine kinase 2 (TYK2) recruitment to IL-12Rβ1 and Janus kinase 2 (JAK2) recruitment to IL-23R. These kinases phosphorylate and activate signal transducer and activator of transcription 3 (STAT3), and to a lesser extent STAT4, STAT1 and STAT5.
The IL-23 Bioassay is a bioluminescent cell-based assay designed to measure IL-23 stimulation or inhibition. IL-23 Bioassay Cells have been engineered to express luc2P in response to IL-23 signaling. When IL-23 binds to IL-23 Bioassay Cells, the receptor transduces intracellular signals resulting in luminescence. The bioluminescent signal is detected and quantified using Bio-Glo™ Reagent.