title: Ultrastructural organisation of HCV from the bloodstream of infected patients revealed by electron microscopy after specific immunocapture.
abstract: HCV particles are associated with very low-density lipoprotein components in chronically infected patients. These hybrid particles, or 'lipo-viro particles' (LVPs), are rich in triglycerides, and contain the viral RNA, the capsid protein, E1E2 envelope glycoproteins and apolipoproteins B and E. However, their specific ultrastructural organisation has yet to be determined. We developed a strategy for the preparation of any viral sample that preserves the native structure of the LVPs, facilitating their precise morphological characterisation.
  
  
  
  Using a strategy based on the direct specific immunocapture of particles on transmission electron microscopy (TEM) grids, we characterised the precise morphology of the viral particle by TEM.
  
  
  
  The LVP consists of a broad nucleocapsid surrounding an electron-dense centre, presumably containing the HCV genome. The nucleocapsid is surrounded by an irregular, detergent-sensitive crescent probably composed of lipids. Lipid content may determine particle size. These particles carry HCV E1E2, ApoB and ApoE, as shown in our immuno-EM analysis. Our results also suggest that these putative LVPs circulate in the serum of patients as part of a mixed population, including lipoprotein-like particles and complete viral particles.
  
  
  
  Twenty-five years after the discovery of HCV, this study finally provides information about the precise morphological organisation of viral particles. It is truly remarkable that our TEM images fully confirm the ultrastructure of LVPs predicted by several authors, almost exclusively from the results of molecular biology studies.
authors.affiliation: INSERM U966, Faculté de Médecine, Université François Rabelais and CHRU de Tours, Tours, France.|Biochimie & Biologie Moléculaire, Hôpital Trousseau, CHRU de Tours, Tours, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Piver
authors.affiliation: INSERM U966, Faculté de Médecine, Université François Rabelais and CHRU de Tours, Tours, France.|Liang Laboratory, Liver Diseases Branch, NIDDK, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Audrey
authors.initials: A
authors.lastname: Boyer
authors.affiliation: Plate-Forme IBiSA des Microscopies, PPF ASB, Université François Rabelais and CHRU de Tours, Tours, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Gaillard
authors.affiliation: INSERM U966, Faculté de Médecine, Université François Rabelais and CHRU de Tours, Tours, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Bull
authors.affiliation: INSERM U966, Faculté de Médecine, Université François Rabelais and CHRU de Tours, Tours, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Beaumont
authors.affiliation: INSERM U966, Faculté de Médecine, Université François Rabelais and CHRU de Tours, Tours, France.|Plate-Forme IBiSA des Microscopies, PPF ASB, Université François Rabelais and CHRU de Tours, Tours, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Roingeard
authors.affiliation: INSERM U966, Faculté de Médecine, Université François Rabelais and CHRU de Tours, Tours, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Meunier
mesh_terms: D000906:Antibodies; D001055:Apolipoproteins B / Q000276:immunology; D001057:Apolipoproteins E / Q000276:immunology; D016174:Hepacivirus / Q000648:ultrastructure*; D019698:Hepatitis C, Chronic / Q000097:blood / Q000821:virology*; D006801:Humans; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D019251:Nucleocapsid / Q000648:ultrastructure; D010455:Peptides / Q000276:immunology; D012367:RNA, Viral / Q000648:ultrastructure*
chemical_list: D000906:Antibodies; D001055:Apolipoproteins B; D001057:Apolipoproteins E; C116123:E1E2 peptide; D010455:Peptides; D012367:RNA, Viral
keywords: HCV; HEPATITIS C; IMAGING; INFECTIOUS DISEASE; LIPID METABOLISM