title: c-Rel regulates interleukin 12 p70 expression in CD8(+) dendritic cells by specifically inducing p35 gene transcription.
abstract: Interleukin 12 (IL-12) is a 70-kD proinflammatory cytokine produced by antigen presenting cells that is essential for the induction of T helper type 1 development. It comprises 35-kD (p35) and 40-kD (p40) polypeptides encoded by separate genes that are induced by a range of stimuli that include lipopolysaccharide (LPS), DNA, and CD40 ligand. To date, the regulation of IL-12 expression at the transcriptional level has mainly been examined in macrophages and restricted almost exclusively to the p40 gene. Here we show that in CD8(+) dendritic cells, major producers of IL-12 p70, the Rel/nuclear factor (NF)-kappaB signaling pathway is necessary for the induction of IL-12 in response to microbial stimuli. In contrast to macrophages which require c-Rel for p40 transcription, in CD8(+) dendritic cells, the induced expression of p35 rather than p40 by inactivated Staphylococcus aureus, DNA, or LPS is c-Rel dependent and regulated directly by c-Rel complexes binding to the p35 promoter. This data establishes the IL-12 p35 gene as a new target of c-Rel and shows that the regulation of IL-12 p70 expression at the transcriptional level by Rel/NF-kappaB is controlled through both the p35 and p40 genes in a cell type-specific fashion.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, The Royal Melbourne Hospital, Victoria 3050, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Grumont
authors.forename: H
authors.initials: H
authors.lastname: Hochrein
authors.forename: M
authors.initials: M
authors.lastname: O'Keeffe
authors.forename: R
authors.initials: R
authors.lastname: Gugasyan
authors.forename: C
authors.initials: C
authors.lastname: White
authors.forename: I
authors.initials: I
authors.lastname: Caminschi
authors.forename: W
authors.initials: W
authors.lastname: Cook
authors.forename: S
authors.initials: S
authors.lastname: Gerondakis
mesh_terms: D000818:Animals; D015415:Biomarkers; D016827:CD8 Antigens; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005260:Female; D005786:Gene Expression Regulation; D018664:Interleukin-12 / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011401:Promoter Regions, Genetic; D020569:Proto-Oncogene Proteins c-rel / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D015415:Biomarkers; D016827:CD8 Antigens; D020569:Proto-Oncogene Proteins c-rel; D018664:Interleukin-12