Interleukin 12 (IL-12), BioAssay(TM) ELISA Kit (Human) (IL-12, Cytotoxic Lymphocyte Maturation Factor 1, CTL Maturation Factor, TcMF, CLMF p35, Natural Killer Cell Stimulatory Factor 1, NFSK1, p35, T cell Stimulating Factor, TSF)

Produktübersicht

• Artikelname: Interleukin 12 (IL-12), BioAssay(TM) ELISA Kit (Human) (IL-12, Cytotoxic Lymphocyte Maturation Factor 1, CTL Maturation Factor, TcMF, CLMF p35, Natural Killer Cell Stimulatory Factor 1, NFSK1, p35, T cell Stimulating Factor, TSF)
• Artikelnummer: USB-I8434-03
• Hersteller Artikelnummer: I8434-03
• Alternativnummer: USB-I8434-03-1
• Hersteller: US Biological
• Kategorie: Kits/Assays
• Applikation: ELISA

Produktbeschreibung

For the quantitative determination of human interleukin 12 IL-12) concentrations in cell culture supernates, serum, plasma, and urine. Recognizes native and recombinant human Il-12 Interleukin 12 (IL-12), also known as natural killer cell stimulatory factor (NKSF) or cytotoxic lymphocyte maturation factor (CLMF), is a pleiotropic cytokine originally identified in the medium of cultured EBV-transformed RPMI-8866 cells (1-3). IL-12 is a 75ka glycoprotein heterodimer composed of two genetically unrelated subunits linked by a disulfide bond. The smaller subunit (p35) has homology to IL-6 and G-CSF while the larger subunit (p40) demonstrates similarity to the soluble receptor for IL-6, leading to the suggestion that IL-12 might have evolved from a cytokine/soluble receptor complex (2-6). IL-12 apparently shows species specificity, with human IL-12 showing minimal activity in the mouse system (3, 7). For reviews on IL-12, see references 8-12. Each subunit of IL-12 apparently arises from a single copy gene. The mRNA transcription of the subunits is closely coordinated, although an excess of the larger subunit has been shown to be produced by B cells in addition to active IL-12 (1, 3). Expression of p35 is reported to be enhanced by simultaneous expression of p40. IL-12 activity cannot be demonstrated in the absence of either chain (3, 4). As suggested by their names, p35 has a native molecular weight of 35ka while p40 has a native molecular weight of 40kD. In humans, p35 is 197 amino acid residues in length with a predicted molecular weight of 22.5kD. This subunit possesses seven cysteines plus three potential N-linked glycosylation sites and the molecule is believed to be heavily glycosylated. The p40 subunit is 306 amino acid residues in length with a predicted molecular weight of 34.7kD. The molecule contains ten cysteine residues and four potential N-linked glycosylation sites (3). The mouse p35 subunit shows 60% sequence identity with the corresponding human subunit and is 193 amino acid residues in length with seven conserved cysteines and one possible N-linked glycosylation site. Mouse p40 shows 70% sequence identity to human p40 and is 313 amino acid residues in length with eleven conserved cysteines and three potential N-linked glycosylation sites (7). It is not clear what separate functions can be attributed to p35 and p40. Preliminary evidence suggests, however, that p40 is involved in receptor binding and p35 is important for signal transduction (13). A unique, high affinity receptor for IL-12 (IL-12 R) has been characterized from PHA-stimulated human peripheral blood mononuclear cells (14). Approximately 110kD as determined by crosslinking studies, it has a Kdin the range of 100-600 pM (14). Cross-linking studies also suggested an association with a second protein of approximately 85kD. IL-12 receptor has also been reported to be present on PHA- or IL-2-stimulated CD4+, CD8+, and CD56+cells and on one T cell and one NK cell line (14, 15). IL-12 is produced by macrophages and B lymphocytes and has been shown to have multiple effects on T cells and natural killer (NK) cells (16, 17). These include inducing production of IFN-and TNF by resting and activated T and NK cells, synergizing with other IFN-inducers at both the transcriptional and post-transcriptional levels to induce IFN-gene expression, enhancing the cytotoxic activity of resting NK and T cells, inducing and synergizing with IL-2 in the generation of lymphokine-activated killer (LAK) cells, acting as a comitogen to stimulate proliferation of resting T cells, and inducing proliferation of activated T and NK cells (16). Evidence indicates that IL-12, produced by macrophages in response to infectious agents, is a central mediator of the cell-mediated immune response by its actions on the development, proliferation, and activities of TH1 cells (8, 9, 18, 19). These activities of IL-12 are antagonized by IL-4 and IL-10, factors associated with the development of unco