title: Mouse tetherin enhances moloney murine leukemia virus-induced syncytium formation.
abstract: Tetherin (also referred to as BST-2 or CD317) is an antiviral cellular restriction factor that inhibits the release of many enveloped viruses. It is a 30-36 kDa type II transmembrane protein, expression of which is induced by type I interferon. Mouse tetherin inhibits nascent cell-free particle release. However, it is unclear whether mouse tetherin restricts cell-to-cell spread of moloney murine leukemia virus (Mo-MLV) or whether is the mouse tetherin involved in syncytium formation. To examine cell-to-cell spread and syncytium formation of Mo-MLV in the presence or absence of mouse tetherin, R peptide (the cytoplasmic tail of the transmembrane protein (TM); 16 amino acids) truncated Env expressing vector was constructed. It contained enhanced green fluorescent protein (EGFP) in the proline rich region (PRR) of Env. This R(-)Env full-length molecular clone could rule out virus-cell transmission due to the slightly reduced R(-)Env protein incorporation into the viral particles. When NIH3T3 cells stably expressing mouse tetherin were transfected with R(-)Env full-length molecular clone, syncytium formation was significantly enhanced in the tetherin-expressing cells. These data suggest that tetherin-mediated retention of R-defective virions on the cell surface could enhance syncytium formation. In addition, we found that the R(-)Env full-length molecular clone containing EGFP in the PRR of Env to be a useful tool allowing fast and convenient detection of syncytia by fluorescence microscopy.
authors.forename: H S
authors.initials: HS
authors.lastname: Kim
authors.forename: S Y
authors.initials: SY
authors.lastname: Han
authors.forename: Y T
authors.initials: YT
authors.lastname: Jung
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D015726:Giant Cells / Q000378:metabolism / Q000821:virology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008979:Moloney murine leukemia virus / Q000235:genetics / Q000502:physiology*; D041681:NIH 3T3 Cells; D012192:Retroviridae Infections / Q000235:genetics / Q000378:metabolism / Q000662:veterinary* / Q000821:virology; D012376:Rodent Diseases / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D014771:Virion / Q000235:genetics / Q000502:physiology; 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
keywords: cell-to-cell transmission; R(-)Env full-length clone; syncytium; tetherin.