title: Regulation of interleukin 12 p40 expression through an NF-kappa B half-site.
abstract: Interleukin 12 (IL-12) is an inducible cytokine composed of 35- and 40-kDa subunits that is critical for promoting T helper type 1 development and cell-mediated immunity against pathogens. The 40-kDa subunit, expressed by activated macrophages and B cells, is induced by several pathogens in vivo and in vitro and is augmented or inhibited by gamma interferon (IFN-gamma) or IL-10, respectively. Control of IL-12 p40 expression is therefore important for understanding resistance and susceptibility to a variety of pathogens, including Leishmania major and perhaps human immunodeficiency virus. In this report, we provide the first characterization of IL-12 p40 gene regulation in macrophages. We localize inducible activity of the promoter to the sequence -122GGGGAATTTTA-132 not previously recognized to bind Rel family transcription factors. We demonstrate binding of this sequence to NF-kappa B (p50/p65 and p50/c-Rel) complexes in macrophages activated by several p40-inducing pathogens and provide functional data to support a role for NF-kappa B family members in IL-12 p40 activation. Finally, we find that IFN-gamma treatment of cells enhances this binding interaction, thus potentially providing a mechanism for IFN-gamma augmentation of IL-12 production by macrophages.
authors.affiliation: Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Murphy
authors.forename: M G
authors.initials: MG
authors.lastname: Cleveland
authors.forename: P
authors.initials: P
authors.lastname: Kulesza
authors.forename: J
authors.initials: J
authors.lastname: Magram
authors.forename: K M
authors.initials: KM
authors.lastname: Murphy
mesh_terms: D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005796:Genes / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000235:genetics*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation; D017737:Macrophages, Peritoneal; D051379:Mice; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D020569:Proto-Oncogene Proteins c-rel; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017384:Sequence Deletion; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D008070:Lipopolysaccharides; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D018664:Interleukin-12; D007371:Interferon-gamma; D004247:DNA