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 many fold 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 p40 protein was purified by immunoaffinity chromatography. The recombinant is > 95% pure, as detemined by SDS-PAGE, and an absorbance assay based on the Beers-Lambert law. The endotoxin level is ≤ 0.1 ng/µg of human IL-12 p40, as measued in a chromogenic LAL assay. This recombinant protein is routinely tested by ELISA. Other applications were tested at BD Biosciences Pharmingen during product development only or reported in the literature.

(RUO)

100 µg/ml

ELISA Standard (Routinely Tested)

IL-12/IL-23 p40

Frozen aqueous buffered solution containing BSA.

Development References(6) 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. Prussin C, Metcalfe DD. Detection of intracytoplasmic cytokine using flow cytometry and directly conjugated anti-cytokine antibodies. J Immunol Methods. 1995; 188(1):117-128. (Methodology: IC/FCM Block). 5. Schoenhaut DS, Chua AO, Wolitzky AG, et al. Cloning and expression of murine IL-12. J Immunol. 1992; 148(11):3433-3440. (Biology). 6. Zeh HJ III, Tahara H, Lotze MT. Interleukin-12. In: Thomson AW, ed. The Cytokine Handbook. London: Academic Press Limited; 1994:239-256.