B-cell epitopes on the hepatitis C virus nucleocapsid protein determined by human monospecific antibodies

Authors

  • Toshitaka Akatsuka,

    1. Division of Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892
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  • Mickhail Donets,

    1. Division of Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892
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  • Luca Scaglione,

    1. Division of Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892
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  • Wei-Mei Ching,

    1. Naval Medical Research Institute, Bethesda, Maryland 20892
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  • J. Wai-Kuo Shih,

    1. Department of Transfusion Medicine, Clinical Medicine, Bethesda, Maryland 20892
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  • Adrian M. Di Bisceglie,

    1. Liver Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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  • Stephen M. Feinstone M. D.

    Corresponding author
    1. Division of Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892
    • Chief, Laboratory of Hepatitis Research, Division of Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Building 29A, Room 1D14, National Institutes of Health, Bethesda, MD 20892
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Abstract

Four monospecific antibodies against the hepatitis C virus nucleocapsid protein, which was expressed by recombinant baculovirus, were obtained by Epstein-Barr virus transformation of B cells from three patients with chronic hepatitis C virus infection. One of these antibodies was IgG and the other three were IgM. Their specificities were characterized initially by enzyme-linked immunosorbent assay and immunoblotting against hepatitis C virus proteins expressed by six recombinant baculoviruses with different hepatitis C virus sequence insertions. These specificities were confirmed, and their epitopes were more precisely determined with a series of overlapping decapeptides made by solid-phase pin technology. Two antibodies (1F4 and 2G6) reacted with the same peptides located near the amino(N)-terminus of nucleocapsid protein (amino acids 33–50). The third antibody (3B5) recognized the peptide consisting of amino acids 133–142, and the fourth antibody (3B9) was mapped to the carboxy(C)-terminus and reacted with a peptide consisting of amino acids 165–174. This epitope has not previously been reported. Two antibodies, 1F4 and 3B9, which are specific to the N-terminus and C-terminus of nucleocapsid protein, respectively, have been stably produced for more than 6 mo and are being subcloned to establish monoclonality. These antibodies should be useful reagents for the study of hepatitis C virus. (HEPATOLOGY 1993;18:503–510.)

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