title: Role of Nectin-1 and Herpesvirus Entry Mediator as Cellular Receptors for Herpes Simplex Virus 1 on Primary Murine Dermal Fibroblasts.
abstract: The cellular proteins nectin-1 and herpesvirus entry mediator (HVEM) can both mediate the entry of herpes simplex virus 1 (HSV-1). We have recently shown how these receptors contribute to infection of skin by investigating HSV-1 entry into murine epidermis. Ex vivo infection studies reveal nectin-1 as the primary receptor in epidermis, whereas HVEM has a more limited role. Although the epidermis represents the outermost layer of skin, the contribution of nectin-1 and HVEM in the underlying dermis is still open. Here, we analyzed the role of each receptor during HSV-1 entry in murine dermal fibroblasts that were deficient in expression of either nectin-1 or HVEM or both receptors. Because infection was not prevented by the absence of either nectin-1 or HVEM, we conclude that they can act as alternative receptors. Although HVEM was found to be highly expressed on fibroblasts, entry was delayed in nectin-1-deficient cells, suggesting that nectin-1 acts as the more efficient receptor. In the absence of both receptors, entry was strongly delayed leading to a much reduced viral spread and virus production. These results suggest an unidentified cellular component that acts as alternate but inefficient receptor for HSV-1 on dermal fibroblasts. Characterization of the cellular entry mechanism suggests that HSV-1 can enter dermal fibroblasts both by direct fusion with the plasma membrane and via endocytic vesicles and that this is not dependent on the presence or absence of nectin-1. Entry was also shown to require dynamin and cholesterol, suggesting comparable entry pathways in keratinocytes and dermal fibroblasts.
  
  
  OBJECTIVE
  Herpes simplex virus (HSV) is a human pathogen which infects its host via mucosal surfaces or abraded skin. To understand how HSV-1 overcomes the protective barrier of mucosa or skin and reaches its receptors in tissue, it is essential to know which receptors contribute to the entry into individual skin cells. Previously, we have explored the contribution of nectin-1 and herpesvirus entry mediator (HVEM) as receptors for HSV-1 entry into murine epidermis, where keratinocytes form the major cell type. Since the underlying dermis consists primarily of fibroblasts, we have now extended our study of HSV-1 entry to dermal fibroblasts isolated from nectin-1- or HVEM-deficient mice or from mice deficient in both receptors. Our results demonstrate a role for both nectin-1 and HVEM as receptors and suggest a further receptor which appears much less efficient.
authors.affiliation: Center for Biochemistry, University of Cologne, Cologne, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Petermann
authors.affiliation: Center for Biochemistry, University of Cologne, Cologne, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Rahn
authors.affiliation: Center for Biochemistry, University of Cologne, Cologne, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Thier
authors.affiliation: Center for Biochemistry, University of Cologne, Cologne, Germany Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Mei-Ju
authors.initials: MJ
authors.lastname: Hsu
authors.affiliation: MRC University of Glasgow Center for Virus Research, Glasgow, United Kingdom.
authors.forename: Frazer J
authors.initials: FJ
authors.lastname: Rixon
authors.affiliation: Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Kopp
authors.affiliation: Center for Biochemistry, University of Cologne, Cologne, Germany Department of Dermatology, University of Cologne, Cologne, Germany dagmar.moersdorf@uni-koeln.de.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Knebel-Mörsdorf
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D020405:Dermis / Q000378:metabolism / Q000473:pathology / Q000821:virology; D004817:Epidermis / Q000378:metabolism / Q000473:pathology / Q000821:virology; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D006561:Herpes Simplex / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018259:Herpesvirus 1, Human / Q000502:physiology*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D000075983:Nectins; D053240:Receptors, Tumor Necrosis Factor, Member 14 / Q000235:genetics / Q000378:metabolism*; D053586:Virus Internalization
chemical_list: D015815:Cell Adhesion Molecules; C000619010:NECTIN1 protein, human; C000619015:Nectin1 protein, mouse; D000075983:Nectins; D053240:Receptors, Tumor Necrosis Factor, Member 14; C506029:Tnfrsf14 protein, mouse