HCV core immunodominant region analysis using mouse monoclonal antibodies and human sera: characterization of major epitopes useful for antigen detection.
Monoclonal antibodies (MAbs) were generated by immunizing mice with a truncated recombinant protein corresponding to the immunodominant region (residues 1-120) of hepatitis C virus (HCV) nucleocapsid protein. The specific recognition by either human sera or mouse monoclonal antibodies of overlapping peptides spanning the core region 1-120 as well as the comparison with epitopes described earlier allowed the fine mapping of HCV core. Within the region 1-120, the major antigenic domain could be restricted to the first 45 amino acids. Indeed, the peptide S42G (residues 2-45) allowed the detection of an anti-HCV core response by all anticore-positive human sera examined. According to their epitope localization, three groups of mouse MABs could be evidenced that were directed against different regions of core. Group II MAbs recognized a strictly linear epitope (QDVKF, residues 20-24), whereas group I MABs were directed against a conformational epitope mainly located at the amino acid residues (QIVGG, 29-33). The epitope of group III MABs was also conformational (PRGRRQPI, residues 58-65). These three epitopes appeared close but different from the three major human epitopes RKTKRNTN, VYLLPR, and GRTWAQPGYPWPLY (residues 7-17, 34-39, and 73-86, respectively). Group II MAB 7G12A8 and group I MAB 19D9D6 were used in a sandwich ELISA for the capture and the detection, respectively, of viral core antigen in sera of patients with chronic HCV infection. After treatment of sera with triton x 100 in acidic conditions, amounts of viral antigen as low as 20 pg/ml of sera could be detected.
Jolivet-Reynaud
C
C
Département des Immunoessais, bioMérieux, Marcy l'Etoile, France. colette.jolivet@ensbma.cnrs.fr
Dalbon
P
P
Viola
F
F
Yvon
S
S
Paranhos-Baccala
G
G
Piga
N
N
Bridon
L
L
Trabaud
M A
MA
Battail
N
N
Sibai
G
G
Jolivet
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D018604:Epitope Mapping; D016174:Hepacivirus / Q000276:immunology*; D006526:Hepatitis C / Q000175:diagnosis / Q000821:virology; D018937:Hepatitis C Antibodies / Q000097:blood; D018936:Hepatitis C Antigens / Q000097:blood / Q000276:immunology*; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology*; D051379:Mice; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology; D014758:Viral Core Proteins / Q000097:blood / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology; D014766:Viremia / Q000175:diagnosis / Q000821:virology
D000911:Antibodies, Monoclonal; D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens; D016056:Immunodominant Epitopes; D010455:Peptides; D012367:RNA, Viral; D011994:Recombinant Proteins; D014758:Viral Core Proteins; D014759:Viral Envelope Proteins; C069130:nucleocapsid protein, Hepatitis C virus