title: Mice lacking the transcription factor CIITA--a second look.
abstract: We have generated a second line of mice lacking a transcription factor thought to be a critical regulator of MHC class II gene expression, CIITA (for class II transactivator). Our and the previously published lines differ in the deletion that was engineered and by the fact that we removed the neomycin-resistance promoter and structural gene via the cre-loxP recombination system. Characterization of our line led to two new findings. First, a substantial number of cells can express class II molecules in the absence of CIITA, albeit at 5-fold reduced levels, most notably dendritic cells in s.c. lymph nodes; therefore, the CIITA gene cannot be an absolute 'master gene' controlling the expression of class II molecules, as had been thought. Second, in contrast to recent results on human cell lines, CIITA is not critically involved in the IFN-gamma-induced up-regulation of MHC class I genes.
authors.affiliation: Institut de Génétique et de Biologie Moléculaire et Cellulaire (CNRS/INSERM/ULP), Strasbourg, France.
authors.forename: G S
authors.initials: GS
authors.lastname: Williams
authors.forename: M
authors.initials: M
authors.lastname: Malin
authors.forename: D
authors.initials: D
authors.lastname: Vremec
authors.forename: C H
authors.initials: CH
authors.lastname: Chang
authors.forename: R
authors.initials: R
authors.lastname: Boyd
authors.forename: C
authors.initials: C
authors.lastname: Benoist
authors.forename: D
authors.initials: D
authors.lastname: Mathis
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D005786:Gene Expression Regulation / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D009687:Nuclear Proteins; D013601:T-Lymphocytes / Q000166:cytology; D015534:Trans-Activators / Q000172:deficiency* / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
chemical_list: D000949:Histocompatibility Antigens Class II; C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D015534:Trans-Activators; D007371:Interferon-gamma