title: Dendritic cell-specific Mgat2 knockout mice show antigen presentation defects but reveal an unexpected CD11c expression pattern.
abstract: Zwitterionic polysaccharide antigens such as polysaccharide A (PSA) from Bacteroides fragilis have been shown to activate CD4+T cells upon presentation by class II major histocompatibility complex (MHCII) on professional antigen presenting cells. For T cell recognition and activation, high affinity binding between MHCII and PSA is required, and complex N-glycans on conserved MHCII asparagine residues play a central role in controlling this interaction. By truncating these glycans in a myeloid-specific knockout of Mgat2, created using the LyzM-CRE mouse (M-cKO), we previously reported defects in PSA responses in vivo. Unfortunately, the M-cKO also showed a propensity to develop common variable immunodeficiency with autoimmune hemolytic anemia features. Here, we describe a novel murine model in which Mgat2 was targeted for ablation using the dendritic cell (DC)-specific CD11c-CRE-GFP strain in order to develop a more specific and robust in vivo model of PSA presentation defects (DC-cKO). This study shows that Mgat2 deficient DCs from DC-cKO mice show ablation of PSA presentation and downstream T cell activation in vitro. However, the CD11c promoter was unexpectedly active and triggered Mgat2 deletion within multiple hematopoietic lineages, showed remarkably poor penetrance within native DC populations, and produced almost undetectable levels of green fluorescent protein signal. These findings show that the CD11c promoter is not DC-specific, and extreme care should be taken in the interpretation of data using any mouse created using the CD11c-CRE model.
authors.affiliation: Department of Pathology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, WRB 5132, Cleveland, OH 44106-7288 Cleveland, OH, USA.
authors.forename: Mark B
authors.initials: MB
authors.lastname: Jones
authors.affiliation: Department of Pathology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, WRB 5132, Cleveland, OH 44106-7288 Cleveland, OH, USA.
authors.forename: Sean O
authors.initials: SO
authors.lastname: Ryan
authors.affiliation: Department of Pathology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, WRB 5132, Cleveland, OH 44106-7288 Cleveland, OH, USA.
authors.forename: Jenny L
authors.initials: JL
authors.lastname: Johnson
authors.affiliation: Department of Pathology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, WRB 5132, Cleveland, OH 44106-7288 Cleveland, OH, USA brian.cobb@case.edu.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Cobb
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000235:genetics* / Q000276:immunology; D001441:Bacteroides fragilis / Q000737:chemistry; D039521:CD11c Antigen / Q000235:genetics*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics* / Q000276:immunology; D011134:Polysaccharides / Q000737:chemistry / Q000276:immunology*; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000276:immunology
chemical_list: D039521:CD11c Antigen; D011134:Polysaccharides; D017351:N-Acetylglucosaminyltransferases; C063313:alpha-1,6-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase
keywords: CRE-LoxP; Mgat2; antigen presentation; dendritic cells; glycoantigen