title: Bone marrow stromal cell antigen 2 (BST-2) restricts mouse mammary tumor virus (MMTV) replication in vivo.
abstract: BACKGROUND
  Bone marrow stromal cell antigen 2 (BST-2) is a cellular factor that restricts the egress of viruses such as human immunodeficiency virus (HIV-1) from the surface of infected cells, preventing infection of new cells. BST-2 is variably expressed in most cell types, and its expression is enhanced by cytokines such as type I interferon alpha (IFN-α). In this present study, we used the beta-retrovirus, mouse mammary tumor virus (MMTV) as a model to examine the role of mouse BST-2 in host infection in vivo.
  
  
  RESULTS
  By using RNA interference, we show that loss of BST-2 enhances MMTV replication in cultured mammary tumor cells and in vivo. In cultured cells, BST-2 inhibits virus accumulation in the culture medium, and co-localizes at the cell surface with virus structural proteins. Furthermore, both scanning electron micrograph (SEM) and transmission electron micrograph (TEM) show that MMTV accumulates on the surface of IFNα-stimulated cells.
  
  
  CONCLUSIONS
  Our data provide evidence that BST-2 restricts MMTV release from naturally infected cells and that BST-2 is an antiviral factor in vivo.
authors.affiliation: Department of Microbiology, University of Iowa, Carver College of Medicine, Iowa City, IA, USA.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Jones
authors.forename: Harshini V
authors.initials: HV
authors.lastname: Mehta
authors.forename: Martina
authors.initials: M
authors.lastname: Maric
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Roller
authors.forename: Chioma M
authors.initials: CM
authors.lastname: Okeoma
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D002460:Cell Line; D020868:Gene Silencing; D008324:Mammary Tumor Virus, Mouse / Q000276:immunology* / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D034622:RNA Interference; D057074:Virus Release; D000074010:Bone Marrow Stromal Antigen 2
chemical_list: D015703:Antigens, CD; D008562:Membrane Glycoproteins; C513868:BST2 protein, mouse; D000074010:Bone Marrow Stromal Antigen 2