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Inhibition of the binding of HCV serum particles to human hepatocytes by E1E2‐specific D32.10 monoclonal antibody
Author(s) -
Ndongo Ndiémé,
Rechoum Yassine,
De Sequeira Sylvie,
Zoulim Fabien,
Trépo Christian,
Drouet Emmanuel,
Petit MarieAnne
Publication year - 2009
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.21562
Subject(s) - monoclonal antibody , microbiology and biotechnology , antibody , binding site , chemistry , antigen , in vitro , hepatocyte , monoclonal , virology , biology , biochemistry , immunology
The aim of this study was to determine the inhibition of binding activity of the monoclonal antibody (mAb) D32.10 which recognizes a highly conserved discontinuous antigenic determinant (E1:297–306, E2:480–494, and E2:613–621) expressed on the surface of serum‐derived HCV particles (HCVsp) of genotypes 1a, 1b, 2a, and 3a. To this end, an in vitro direct cell‐binding assay based on the attachment of radiolabeled HCVsp was developed, and Scatchard plots were used to analyze ligand–receptor binding data. HCV adsorption was also assessed by quantitating cell‐associated viral RNA by a real‐time RT‐PCR method. Saturable concentration‐dependent specific binding of HCVsp to Huh‐7 or HepaRG cells was demonstrated. The Scatchard transformed data showed two‐site interaction for Huh‐7 and proliferative HepaRG cells: the high‐affinity binding sites (K d1 = 0.1–0.5 µg/ml) and the low‐affinity binding sites (K d1 = 5–10 µg/ml), and one‐site high‐affinity binding model between E1E2/D32.10‐positive HCVsp and hepatocyte‐like differentiated HepaRG cells. The E1E2‐specific mAb D32.10 inhibited efficiently (>60%) and selectively the binding with an IC 50 ≤0.5 µg/ml in all the experimental approaches using serum HCV of genotype either 3 or 1b. This supports the involvement of the E1E2/D32.10 discontinuous antigenic determinant in the interactions between human hepatocytes and HCVsp, and suggests that D32.10‐like antibodies present in sera from patients infected with HCV could play a protective role. J. Med. Virol. 81:1726–1733, 2009. © 2009 Wiley‐Liss, Inc.