title: Selective Expression of the MAPK Phosphatase Dusp9/MKP-4 in Mouse Plasmacytoid Dendritic Cells and Regulation of IFN-β Production.
abstract: Plasmacytoid dendritic cells (pDCs) efficiently produce large amounts of type I IFN in response to TLR7 and TLR9 ligands, whereas conventional DCs (cDCs) predominantly secrete high levels of the cytokines IL-10 and IL-12. The molecular basis underlying this distinct phenotype is not well understood. In this study, we identified the MAPK phosphatase Dusp9/MKP-4 by transcriptome analysis as selectively expressed in pDCs, but not cDCs. We confirmed the constitutive expression of Dusp9 at the protein level in pDCs generated in vitro by culture with Flt3 ligand and ex vivo in sorted splenic pDCs. Dusp9 expression was low in B220(-) bone marrow precursors and was upregulated during pDC differentiation, concomitant with established pDC markers. Higher expression of Dusp9 in pDCs correlated with impaired phosphorylation of the MAPK ERK1/2 upon TLR9 stimulation. Notably, Dusp9 was not expressed at detectable levels in human pDCs, although these displayed similarly impaired activation of ERK1/2 MAPK compared with cDCs. Enforced retroviral expression of Dusp9 in mouse GM-CSF-induced cDCs increased the expression of TLR9-induced IL-12p40 and IFN-β, but not of IL-10. Conditional deletion of Dusp9 in pDCs was effectively achieved in Dusp9(flox/flox); CD11c-Cre mice at the mRNA and protein levels. However, the lack of Dusp9 in pDC did not restore ERK1/2 activation after TLR9 stimulation and only weakly affected IFN-β and IL-12p40 production. Taken together, our results suggest that expression of Dusp9 is sufficient to impair ERK1/2 activation and enhance IFN-β expression. However, despite selective expression in pDCs, Dusp9 is not essential for high-level IFN-β production by these cells.
authors.affiliation: Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen, 91054 Erlangen, Germany;
authors.forename: Magdalena
authors.initials: M
authors.lastname: Niedzielska
authors.affiliation: Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen, 91054 Erlangen, Germany;
authors.forename: Faizal A M
authors.initials: FA
authors.lastname: Raffi
authors.affiliation: Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, 6525 GA Nijmegen, the Netherlands;
authors.forename: Jurjen
authors.initials: J
authors.lastname: Tel
authors.affiliation: Cancer Research UK Stress Response Laboratory, Division of Cancer Research, Medical Research Institute, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, Dundee DD1 9SY, United Kingdom;
authors.forename: Sandra
authors.initials: S
authors.lastname: Muench
authors.affiliation: Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen, 91054 Erlangen, Germany;
authors.forename: Katrin
authors.initials: K
authors.lastname: Jozefowski
authors.affiliation: Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen, 91054 Erlangen, Germany;
authors.forename: Nour
authors.initials: N
authors.lastname: Alati
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene, Technical University Munich, 81675 Munich, Germany; Section of Virology, National Veterinary Institute, Technical University of Denmark, 1870 Frederiksberg, Denmark; Immunology Section, Lund University, 221 00 Lund, Sweden;
authors.forename: Katharina
authors.initials: K
authors.lastname: Lahl
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene, Technical University Munich, 81675 Munich, Germany;
authors.forename: Jörg
authors.initials: J
authors.lastname: Mages
authors.affiliation: Medical Clinic 1, University Hospital Erlangen, 91054 Erlangen, Germany;
authors.forename: Ulrike
authors.initials: U
authors.lastname: Billmeier
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene, Technical University Munich, 81675 Munich, Germany;
authors.forename: Matthias
authors.initials: M
authors.lastname: Schiemann
authors.affiliation: Cell Sorting Unit, Nikolaus-Fiebiger-Center for Molecular Medicine, 91054 Erlangen, Germany;
authors.forename: Uwe K
authors.initials: UK
authors.lastname: Appelt
authors.affiliation: Medical Clinic 1, University Hospital Erlangen, 91054 Erlangen, Germany;
authors.forename: Stefan
authors.initials: S
authors.lastname: Wirtz
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene, Technical University Munich, 81675 Munich, Germany; TWINCORE-Centre for Experimental and Clinical Infection Research, 30625 Hannover, Germany; and.
authors.forename: Tim
authors.initials: T
authors.lastname: Sparwasser
authors.affiliation: Department of Research, Bavarian Nordic GmbH, 82152 Martinsried, Germany.
authors.forename: Hubertus
authors.initials: H
authors.lastname: Hochrein
authors.affiliation: Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, 6525 GA Nijmegen, the Netherlands;
authors.forename: Carl G
authors.initials: CG
authors.lastname: Figdor
authors.affiliation: Cancer Research UK Stress Response Laboratory, Division of Cancer Research, Medical Research Institute, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, Dundee DD1 9SY, United Kingdom;
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Keyse
authors.affiliation: Institute of Clinical Microbiology, Immunology and Hygiene, University Hospital Erlangen, 91054 Erlangen, Germany; Institute of Medical Microbiology, Immunology and Hygiene, Technical University Munich, 81675 Munich, Germany; roland.lang@uk-erlangen.de.
authors.forename: Roland
authors.initials: R
authors.lastname: Lang
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D054637:Dual-Specificity Phosphatases / Q000235:genetics*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D016899:Interferon-beta / Q000096:biosynthesis* / Q000235:genetics; D018664:Interleukin-12; D051379:Mice; D018345:Mice, Knockout; D009928:Organ Specificity / Q000235:genetics; D010766:Phosphorylation; D015203:Reproducibility of Results; D051199:Toll-Like Receptor 7 / Q000378:metabolism; D051217:Toll-Like Receptor 9 / Q000378:metabolism; D059467:Transcriptome
chemical_list: D051199:Toll-Like Receptor 7; D051217:Toll-Like Receptor 9; D018664:Interleukin-12; D016899:Interferon-beta; D048049:Extracellular Signal-Regulated MAP Kinases; D054637:Dual-Specificity Phosphatases; C484491:Dusp9 protein, mouse