title: Identification of CIITA regulated genetic module dedicated for antigen presentation.
abstract: The class II trans-activator CIITA is a transcriptional co-activator required for the expression of Major Histocompatibility Complex (MHC) genes. Although the latter function is well established, the global target-gene specificity of CIITA had not been defined. We therefore generated a comprehensive list of its target genes by performing genome-wide scans employing four different approaches designed to identify promoters that are occupied by CIITA in two key antigen presenting cells, B cells and dendritic cells. Surprisingly, in addition to MHC genes, only nine new targets were identified and validated by extensive functional and expression analysis. Seven of these genes are known or likely to function in processes contributing to MHC-mediated antigen presentation. The remaining two are of unknown function. CIITA is thus uniquely dedicated for genes implicated in antigen presentation. The finding that CIITA regulates such a highly focused gene expression module sets it apart from all other transcription factors, for which large-scale binding-site mapping has indicated that they exert pleiotropic functions and regulate large numbers of genes.
authors.affiliation: University of Geneva Medical School, CMU, Geneva, Switzerland.
authors.forename: Michal
authors.initials: M
authors.lastname: Krawczyk
authors.forename: Queralt
authors.initials: Q
authors.lastname: Seguín-Estévez
authors.forename: Elisa
authors.initials: E
authors.lastname: Leimgruber
authors.forename: Peter
authors.initials: P
authors.lastname: Sperisen
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmid
authors.forename: Philipp
authors.initials: P
authors.lastname: Bucher
authors.forename: Walter
authors.initials: W
authors.lastname: Reith
mesh_terms: D017951:Antigen Presentation / Q000235:genetics*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D005802:Genes, MHC Class II; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins; D000071701:Regulatory Factor X Transcription Factors; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D004268:DNA-Binding Proteins; C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D000071701:Regulatory Factor X Transcription Factors; D015534:Trans-Activators; D014157:Transcription Factors; D007371:Interferon-gamma; D004247:DNA