title: Antibody-mediated enhancement of HIV-1 and HIV-2 production from BST-2/tetherin-positive cells.
abstract: BST-2/CD317/HM1.24/tetherin is a B-cell antigen overexpressed on the surface of myeloma cell lines and on neoplastic plasma cells of patients with multiple myeloma. Antibodies to BST-2 are in clinical trial for the treatment of multiple myeloma and are considered for the treatment of solid tumors with high BST-2 antigen levels. Functionally, BST-2 restricts the secretion of retroviruses, including human immunodeficiency virus type 1, as well as members of the herpesvirus, filovirus, and arenavirus families, presumably by tethering nascent virions to the cell surface. Here we report that BST-2 antibody treatment facilitates virus release from BST-2(+) cells by interfering with the tethering activity of BST-2. BST-2 antibodies were unable to release already tethered virions and were most effective when added early during virus production. BST-2 antibody treatment did not affect BST-2 dimerization and did not reduce the cell surface expression of BST-2. Interestingly, BST-2 antibody treatment reduced the nonspecific shedding of BST-2 and limited the encapsidation of BST-2 into virions. Finally, flotation analyses indicate that BST-2 antibodies affect the distribution of BST-2 within membrane rafts. Our data suggest that BST-2 antibody treatment may enhance virus release by inducing a redistribution of BST-2 at the cell surface, thus preventing it from accumulating at the sites of virus budding.
authors.affiliation: Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460, Bethesda, Maryland 20892-0460, USA.
authors.forename: Eri
authors.initials: E
authors.lastname: Miyagi
authors.forename: Amy
authors.initials: A
authors.lastname: Andrew
authors.forename: Sandra
authors.initials: S
authors.lastname: Kao
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Klaus
authors.initials: K
authors.lastname: Strebel
mesh_terms: D000906:Antibodies / Q000378:metabolism*; D015703:Antigens, CD / Q000276:immunology*; D002460:Cell Line; D058851:GPI-Linked Proteins / Q000037:antagonists & inhibitors / Q000276:immunology; D015497:HIV-1 / Q000254:growth & development / Q000502:physiology*; D015498:HIV-2 / Q000254:growth & development / Q000502:physiology*; D006801:Humans; D057074:Virus Release; D000074010:Bone Marrow Stromal Antigen 2
chemical_list: D000906:Antibodies; D015703:Antigens, CD; D058851:GPI-Linked Proteins; C094572:BST2 protein, human; D000074010:Bone Marrow Stromal Antigen 2