B-cell epitopes on the hepatitis C virus nucleocapsid protein determined by human monospecific antibodies.
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.
Akatsuka
T
T
Division of Virology, Food and Drug Administration, National Institutes of Health, Bethesda, Maryland 20892.
Donets
M
M
Scaglione
L
L
Ching
W M
WM
Shih
J W
JW
Di Bisceglie
A M
AM
Feinstone
S M
SM
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002461:Cell Line, Transformed; D000939:Epitopes / Q000032:analysis*; D016174:Hepacivirus / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000096:biosynthesis / Q000276:immunology*; D006526:Hepatitis C / Q000097:blood / Q000276:immunology*; D018937:Hepatitis C Antibodies; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification; D014758:Viral Core Proteins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D000939:Epitopes; D006508:Hepatitis Antibodies; D018937:Hepatitis C Antibodies; D007074:Immunoglobulin G; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus