title: A second form of infectious bursal disease virus-associated tubule contains VP4.
abstract: Preparations of density gradient-purified infectious bursal disease virus (IBDV) were found to contain full and empty icosahedral virions, type I tubules with a diameter of about 60 nm, and type II tubules 24 to 26 nm in diameter. By immunoelectron microscopy we demonstrate that virions and both types of tubular structures specifically react with anti-IBDV serum. In infected cells intracytoplasmic and intranuclear type II tubules reacted exclusively with an anti-VP4 monoclonal antibody, as did type II tubules in virion preparations. The immunofluorescence pattern with the anti-VP4 antibody correlated with electron microscopical findings. Neither purified extracellular nor intracellular virions were labeled with the anti-VP4 MAb. Our data show that the type II tubules contain VP4 and suggest that VP4 is not part of the virus particle.
authors.affiliation: Institutes of Diagnostic Virology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, Insel Riems, Germany. Harald.Granzow@rie.bfav.de
authors.forename: H
authors.initials: H
authors.lastname: Granzow
authors.forename: C
authors.initials: C
authors.lastname: Birghan
authors.forename: T C
authors.initials: TC
authors.lastname: Mettenleiter
authors.forename: J
authors.initials: J
authors.lastname: Beyer
authors.forename: B
authors.initials: B
authors.lastname: Köllner
authors.forename: E
authors.initials: E
authors.lastname: Mundt
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000956:Antigens, Viral / Q000378:metabolism; D018175:Birnaviridae Infections / Q000473:pathology / Q000821:virology*; D002213:Capsid / Q000737:chemistry* / Q000276:immunology; D036022:Capsid Proteins; D002478:Cells, Cultured; D002642:Chick Embryo; D003593:Cytoplasm / Q000648:ultrastructure; D019084:Fluorescent Antibody Technique, Indirect; D007243:Infectious bursal disease virus / Q000737:chemistry* / Q000648:ultrastructure; D008854:Microscopy, Electron; D014771:Virion / Q000737:chemistry / Q000648:ultrastructure
chemical_list: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D036022:Capsid Proteins; C060339:VP4 protein, Rotavirus