Human IL-23 ELISA Ready-SET-Go!® Set

Description: This Human IL-23 Ready-SET-Go! ELISA Set contains the necessary reagents, standards, buffers and diluents for performing quantitative enzyme-linked immunosorbent assays (ELISA). This ELISA set is specifically engineered for accurate and precise measurement of human IL-23 protein levels from samples including serum, plasma, and supernatants from cell cultures. Interference with CpG oligodeoxynucleotides (or CpG ODN) has been observed with this ELISA kit. An improved sample diluent has been included that minimizes this effect; however, controls should still be added when utilizing the CpG compound in this assay. The assay demonstrates parallelism in measuring recombinant and native human IL-23 proteins with a standard curve range of 15 pg/ml to 2,000 pg/ml, and assay sensitivity below 15 pg/ml. The assay has been validated by specific detection of significant levels of native human IL-23 protein in supernatants from a variety of different activated dendritic cell populations. The use of a p19-specific capture antibody and a p40-specific detection antibody renders this sandwich ELISA exquisitely specific for human IL-23. IL-12 p40 monomer and IL-12 p70 were run in the assay at 200 ng/ml with no interference or cross-reactivity observed. A panel of 20 unrelated cytokines was also run in the IL-23 ELISA at 100 ng/ml with no cross reactivity observed.

IL-23 is a heterodimeric cytokine composed of the p40 subunit of IL-12 disulfide-linked with a protein p19. p19, like p35 of IL-12, is biologically inactive by itself. IL-23 interacts with IL-12Rbeta1 and an additional, novel beta2-like receptor subunit with STAT4 binding domain, termed IL-23R. IL-23 is secreted by activated mouse and human dendritic cells. Biological activities of mouse IL-23 are distinct from those of mouse IL-12. Mouse IL-23 was found not to induce significant amounts of IFN-g. Mouse IL-23 does induce strong proliferation of memory T cells (but not naïve T cells), whereas IL-12 has no effect on memory cells. Additionally, mouse IL-23 (but not IL-12) can activate mouse memory T cells to produce the proinflammatory cytokine IL-17. Human IL-23 has biological properties which are less distinct from human IL-12; human IL-23 induces proliferation of memory T cells and induces moderate levels of IFN-g production by naïve and memory T cells, as compared to IL-12.IL-23-dependent, IL-17-producing CD4+ T cells (Th-17 cells) have been identified as a unique subset of Th cells that develops along a pathway that is distinct from the Th1- and Th2- cell differentiation pathways. The hallmark effector molecules of Th1 and Th2 cells, e.g., IFN-g and IL-4, have each been found to negatively regulate the generation of these Th-17 cells. More recently, de novo differentiation of Th-17 cells in the absence of IL-23 has been demonstrated by treatment of naïve CD4 cells with TGF-β1 and IL-6.

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