Interleukin-23

Interleukin-23 (IL-23) belongs to the IL-12 family and is a heterodimer of the p40 and p19 subunits. Production of IL-23 is generally limited to dendritic cells, monocytes, and macrophages, in addition to B cells and endothelial cells. Potent activators of IL-23 are ligands of pattern associated molecular patterns, such as toll-like receptors (TLR-2, 4 and 8). The receptor for IL-23 is also comprised of two different subunits, IL-12Rb1 and IL-23R and signals through JAK2/Tyk2. The functional IL-23 receptor is expressed mainly on lymphocytes, such as activated T cells (most notably T cell helper type, TH, 17), gamma delta T cells, natural killer cells, and innate lymphoid cells. From the expression pattern of the IL-23 receptor, the action of IL-23 is mainly on directing lymphocyte function and activity. One of the most notable actions of IL-23 is in promoting and enhancing the IL-17 response. While IL-23 does not differentiate na?ve T cells into TH17 cells, IL-23 is a main driver for the maintenance, survival, and expansion of TH17. The interplay between these two cytokines is now commonly referred to as the IL-23/IL-17 axis. As such, targeting IL-23 is an alternative strategy in suppressing the IL-17/TH17 immune induced pathogenesis.

Swiss-Prot Accession Number: Q9NPF7