title: Equid herpesvirus 1 (EHV1) infection of equine mesenchymal stem cells induces a pUL56-dependent downregulation of select cell surface markers.
abstract: Equid herpesvirus 1 (EHV1) is an ubiquitous alphaherpesvirus that can cause respiratory disease, abortion and central nervous disorders. EHV1 is known to infect a variety of different cell types in vitro, but its tropism for cultured primary equine mesenchymal stem cells (MSC) has never been explored. We report that equine MSC were highly permissive for EHV1 and supported lytic replication of the virus in vitro. Interestingly, we observed that an infection of MSC with EHV1 resulted in a consistent downregulation of cell surface molecules CD29 (β1-integrin), CD105 (endoglin), major histocompatibility complex type I (MHCI) and a variable downregulation of CD172a. In contrast, expression of CD44 and CD90 remained unchanged upon wild type infection. In addition, we found that this selective EHV1-mediated downregulation of cell surface proteins was dependent on the viral protein UL56 (pUL56). So far, pUL56-dependent downregulation during EHV1 infection of equine cells has only been described for MHCI, but our present data indicate that pUL56 may have a broader function in downregulating cell surface proteins. Taken together, our results are the first to show that equine MSC are susceptible for EHV1 and that pUL56 induces downregulation of several cell surface molecules on infected cells. These findings provide a basis for future studies to evaluate the mechanisms underlying for this selective pUL56-induced downregulation and to evaluate the potential role of MSC during EHV1 pathogenesis.
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Claessen
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium.
authors.forename: Herman
authors.initials: H
authors.lastname: Favoreel
authors.affiliation: Institut für Virologie, Freie Universität Berlin, 10115 Berlin, Germany.
authors.forename: Guanggang
authors.initials: G
authors.lastname: Ma
authors.affiliation: Institut für Virologie, Freie Universität Berlin, 10115 Berlin, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Osterrieder
authors.affiliation: Department of Obstetrics, Reproduction and Herd Health, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium.
authors.forename: Catharina
authors.initials: C
authors.lastname: De Schauwer
authors.affiliation: Department of Obstetrics, Reproduction and Herd Health, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Piepers
authors.affiliation: Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium; Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA. Electronic address: grv23@cornell.edu.
authors.forename: Gerlinde R
authors.initials: GR
authors.lastname: Van de Walle
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D015536:Down-Regulation; D005786:Gene Expression Regulation; D006566:Herpesviridae Infections / Q000662:veterinary* / Q000821:virology; D004861:Herpesvirus 1, Equid / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D006736:Horses; D054884:Host-Pathogen Interactions; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000821:virology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000914:Antibodies, Viral; D015415:Biomarkers; D008565:Membrane Proteins; D014764:Viral Proteins
keywords: CD105; CD172a; CD29; EHV1; MSC; pUL56