title: Coexpression of hepatitis C virus E1 and E2 chimeric envelope glycoproteins displays separable ligand sensitivity and increases pseudotype infectious titer.
abstract: We have previously reported that a pseudotype virus generated by reconstitution of hepatitis C virus (HCV) chimeric envelope glycoprotein E1-G or E2-G on the surface of a temperature-sensitive mutant of vesicular stomatitis virus (VSVts045) interacts independently with mammalian cells to initiate infection. Here, we examined whether coexpression of both of the envelope glycoproteins on pseudotype particles would augment virus infectivity and/or alter the functional properties of the individual subunits. Stable transfectants of baby hamster kidney (BHK) epithelial cells expressing either one or both of the chimeric envelope glycoproteins of HCV on the cell surface were generated. The infectious titer of the VSV pseudotype, derived from a stable cell line incorporating both of the chimeric glycoproteins of HCV, was approximately 4- to 5-fold higher than that of a pseudotype bearing E1-G alone or approximately 25- to 30-fold higher than that of E2-G alone when assayed with a number of mammalian cell lines. Further studies suggested that that the E1-G/E2-G or E2-G pseudotype was more sensitive to the inhibitory effect of heparin than the E1-G pseudotype. Treatment of the E1-G/E2-G pseudotype with a negatively charged sulfated sialyl lipid (NMSO3) displayed a approximately 4-fold-higher sensitivity to neutralization than pseudotypes with either of the two individual glycoproteins. In contrast, VSVts045, used as a backbone for the generation of pseudotypes, displayed at least 20-fold-higher sensitivity to NMSO3-mediated inhibition of virus plaque formation. The effect of low-density lipoprotein on the E1-G pseudotype was greater than that apparent for the E1-G/E2-G pseudotype. The treatment of cells with monoclonal antibodies to CD81 displayed an inhibitory effect upon the pseudotype with E1-G/E2-G or with E2-G alone. Taken together, our results indicate that the HCV E1 and E2 glycoproteins have separable functional properties and that the presence of these two envelope glycoproteins on VSV/HCV pseudotype particles increases infectious titer.
authors.affiliation: Division of Infectious Diseases and Immunology, Saint Louis University, 3635 Vista Ave., FDT-8N, St. Louis, MO 63110, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Meyer
authors.forename: Aster
authors.initials: A
authors.lastname: Beyene
authors.forename: Terry L
authors.initials: TL
authors.lastname: Bowlin
authors.forename: Arnab
authors.initials: A
authors.lastname: Basu
authors.forename: Ranjit
authors.initials: R
authors.lastname: Ray
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000502:physiology; D006224:Cricetinae; D016174:Hepacivirus / Q000502:physiology*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008055:Lipids / Q000494:pharmacology; D051379:Mice; D019158:N-Acetylneuraminic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D011973:Receptors, LDL / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000502:physiology*; D060225:Tetraspanin 28; D014721:Vesicular stomatitis Indiana virus / Q000502:physiology; D014759:Viral Envelope Proteins / Q000502:physiology*
chemical_list: C413863:(2,2-bis(docosyloxymethyl)propyl-5-acetamido-3,5-dideoxy-4,7,8,9-tetra-O-(sodium oxysulfonyl)glycero-alpha-galacto-2-nonulopyranosid)onate; D015703:Antigens, CD; C554798:CD81 protein, human; C554799:Cd81 protein, mouse; C087035:E1 protein, Hepatitis C virus; D008055:Lipids; D011973:Receptors, LDL; D011993:Recombinant Fusion Proteins; D060225:Tetraspanin 28; D014759:Viral Envelope Proteins; C091015:glycoprotein E2, Hepatitis C virus; D006493:Heparin; D019158:N-Acetylneuraminic Acid