Inhibition of hepatitis C virus-like particle binding to target cells by antiviral antibodies in acute and chronic hepatitis C.
Hepatitis C virus (HCV) is a leading cause of chronic viral hepatitis worldwide. The study of antibody-mediated virus neutralization has been hampered by the lack of an efficient and high-throughput cell culture system for the study of virus neutralization. The HCV structural proteins have been shown to assemble into noninfectious HCV-like particles (HCV-LPs). Similar to serum-derived virions, HCV-LPs bind and enter human hepatocytes and hepatoma cell lines. In this study, we developed an HCV-LP-based model system for a systematic functional analysis of antiviral antibodies from patients with acute or chronic hepatitis C. We demonstrate that cellular HCV-LP binding was specifically inhibited by antiviral antibodies from patients with acute or chronic hepatitis C in a dose-dependent manner. Using a library of homologous overlapping envelope peptides covering the entire HCV envelope, we identified an epitope in the N-terminal E2 region (SQKIQLVNTNGSWHI; amino acid positions 408 to 422) as one target of human antiviral antibodies inhibiting cellular particle binding. Using a large panel of serum samples from patients with acute and chronic hepatitis C, we demonstrated that the presence of antibodies with inhibition of binding activity was not associated with viral clearance. In conclusion, antibody-mediated inhibition of cellular HCV-LP binding represents a convenient system for the functional characterization of human anti-HCV antibodies, allowing the mapping of envelope neutralization epitopes targeted by naturally occurring antiviral antibodies.
Department of Medicine II, University of Freiburg, Freiburg, Germany.
Daniel
D
Steinmann
Heidi
H
Barth
Bettina
B
Gissler
Peter
P
Schürmann
Mohammed I
MI
Adah
J Tilman
JT
Gerlach
Gerd R
GR
Pape
Erik
E
Depla
Dirk
D
Jacobs
Geert
G
Maertens
Arvind H
AH
Patel
Geneviève
G
Inchauspé
T Jake
TJ
Liang
Hubert E
HE
Blum
Thomas F
TF
Baumert
D000208:Acute Disease; D045744:Cell Line, Tumor; D018604:Epitope Mapping; D016174:Hepacivirus / Q000145:classification / Q000276:immunology* / Q000502:physiology*; D006526:Hepatitis C / Q000276:immunology* / Q000821:virology*; D018937:Hepatitis C Antibodies / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology* / Q000821:virology*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D014759:Viral Envelope Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D014771:Virion / Q000145:classification / Q000276:immunology / Q000378:metabolism
D018937:Hepatitis C Antibodies; D007106:Immune Sera; D014759:Viral Envelope Proteins