Recombinant Human IL-23 (carrier-free)

Interleukin 23 (IL-23) is a member of the IL-6 family of cytokines, and it is comprised of two subunits, p19 and p40. The p19/p40 heterodimer is stabilized by a disulfide bond. The p40 subunit is shared by IL-23 and IL-12 cytokines. p19 mRNA is expressed in endothelial cells and polarized T cells; p40 is not expressed by these cells. Therefore, the availability of functional IL-23 is limited by the expression of p40 and not p19. IL-23 exerts its biological activities through the interaction with a heterodimeric receptor complex composed of IL-12Rb1 and IL-23R. IL-23 activates Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling molecules. JAK2 is constitutively associated with the IL-23R chain, and binding of IL-23 to its receptor leads to phosphorylation of STAT1, STAT3, STAT4, and STAT5.