Invitrogen™ IL-12 p70 Mouse ELISA Development Kit (ABTS), PeproTech®, PeproTech®

Interleukin-12 (IL-12) is a heterodimeric 70 kDa cytokine composed of two covalently linked, glycosylated chains with molecular weights of 40kD (p40) and 35-kD (p35). IL-12 is mainly produced by monocytes, macrophages, and dendritic cells in response to bacterial products such as lipopolysaccharides (LPS), to intracellular pathogens or upon interaction with activated T cells. IL-12 was originally discovered because of its ability to induce interferon-gamma (IFN-g) production, cell proliferation, and cytotoxicity mediated by natural killer cells and T cells. Studies have established that IL-12 also plays a key role in the development of Th1 responses, leading to IFN-g and IL-2 production. These cytokines can in turn promote T-cell responses and macrophage activation. Recombinant mouse IL-12 p70 is produced in baculovirus-infected insect cells as an authentic heterodimer of precursor p35 and p40 subunits using a dual promoter expression system. IL-12 p70 is distinct from other available forms of the protein in that it is expressed as a true heterodimer, as opposed to a single-chain, pseudo-heterodimer in which the subunits are joined by an artificial linker. The responses of lymphocytes to this cytokine are mediated by the activator of transcription protein STAT4. Nitric oxide synthase 2A (NOS2A/NOS2) is found to be required for the signaling process of this cytokine in innate immunity. Human and mouse IL-12 p40 share about 70% amino acid sequence homology.