Interleukin-12 (IL-12) is a potent regulator of cell-mediated immune responses. Biologically active IL-12 is secreted by activated B lymphocytes and macrophages as a 70 kD heterodimeric glycoprotein comprised of disulfide-bonded 35 kD (p35) and 40 kD (p40) subunits.  The IL-12 p40 monomer shares amino acid sequence homology with the IL-6 receptor.  It has been reported that activated PBMC produce a manyfold excess of IL-12 p40 monomer over the bioactive p70 heterodimer.  The IL-12 p40 monomer has been reported to inhibit binding of IL-12 p70 to the IL-12 receptor, but with 20X less effectiveness than the IL-12 p70 homodimer.  Recombinant human IL-12 p70 (Cat. No. 554613) is supplied as a frozen liquid comprised of 0.22 μm sterile-filtered aqueous buffered solution, containing  bovine serum albumin and glycerol, with no preservatives.  Purity is ≥ 95% as determined by non-reducing SDS-PAGE, and an absorbance assay based on the Beers-Lambert Law. The endotoxin level is ≤ 0.1 ng per μg of human IL-12 p70, as measured in a chromogenic LAL assay.

(RUO)

100 µg/ml

ELISA Standard (Routinely Tested), Bioassay (Tested During Development)

Human (QC Testing)

IL-12

Frozen aqueous buffered solution containing BSA and glycerol.

Development References(5) 1. D'Andrea A, Aste-Amezaga M, Valiante NM, Ma X, Kubin M, Trinchieri G. Interleukin 10 (IL-10) inhibits human lymphocyte interferon gamma-production by suppressing natural killer cell stimulatory factor/IL-12 synthesis in accessory cells. J Exp Med. 1993; 178(3):1041-1048. (Biology). 2. D'Andrea A, Rengaraju M, Valiante NM, et al. Production of natural killer cell stimulatory factor (interleukin 12) by peripheral blood mononuclear cells. J Exp Med. 1992; 176(5):1387-1398. (Biology). 3. Ling P, Gately MK, Gubler U, et al. Human IL-12 p40 homodimer binds to the IL-12 receptor but does not mediate biologic activity. J Immunol. 1995; 154(1):116-127. (Biology). 4. Stern AS, Podlaski FJ, Hulmes JD, et al. Purification to homogeneity and partial characterization of cytotoxic lymphocyte maturation factor from human B-lymphoblastoid cells. Proc Natl Acad Sci U S A. 1990; 87(17):6808-6812. (Biology). 5. Zeh HJ III, Tahara H, Lotze MT. Interleukin-12. In: Thomson AW, ed. The Cytokine Handbook. London: Academic Press Limited; 1994:239-256.