title: Antigenic regions within the hepatitis C virus envelope 1 and non-structural proteins: identification of an IgG3-restricted recognition site with the envelope 1 protein.
abstract: Antibody binding to antigenic regions of hepatitis C virus (HCV) envelope 1 (E1; residues 183-380, E2/non-structural (NS) 1 (residues 380-437), NS1 (residues 643-690), and NS4 (1684-1751) proteins were assayed for 50 sera with antibodies to HCV (anti-HCV) and for 46 sera without anti-HCV. Thirty-four peptides, 18 residues long with an eight-amino acid overlap within each HCV region, were synthesized and tested with all 96 sera. Within the E region 183-380, the major binding site was located to residues 203-220, and was recognized by eight sera. Within the E2/NS1 region 380-437, the peptide covering residues 410-427 was recognized by two sera, and within the NS1 region 643-690, peptides covering residues 663-690 were recognized by four sera. Within the NS4 region 1684-1751, 27 sera were reactive to one or more of the NS4 peptides, and 21 out of these were reactive with peptide 1694-1711. One part of the major binding site could be located to residues 1701-1704, with the sequence Leu-Tyr-Arg-Glu. The IgG1, IgG3 and IgG4 subclasses were reactive with the five antigenic regions of HCV core, residues 1-18, 11-28, 21-38, 51-68 and 101-118. Reactivity to the major envelope site consisted almost exclusively of IgG3, and reactivity to the major site of NS4 consisted only of IgG1. Thus, a non-restricted IgG response to linear HCV-encoded binding sites was found to the core protein, whereas IgG subclass-restricted linear binding sites were found within the E1 protein, and within the NS4 protein.
authors.affiliation: Department of Virology, National Bacteriological Laboratory, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Sällberg
authors.forename: U
authors.initials: U
authors.lastname: Rudén
authors.forename: B
authors.initials: B
authors.lastname: Wahren
authors.forename: L O
authors.initials: LO
authors.lastname: Magnius
mesh_terms: D000595:Amino Acid Sequence; D001666:Binding Sites, Antibody / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D016174:Hepacivirus / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000276:immunology; D006526:Hepatitis C / Q000276:immunology; D018937:Hepatitis C Antibodies; D006801:Humans; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000276:immunology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D014759:Viral Envelope Proteins / Q000276:immunology*; D017361:Viral Nonstructural Proteins / Q000276:immunology*
chemical_list: D000939:Epitopes; D006508:Hepatitis Antibodies; D018937:Hepatitis C Antibodies; D007074:Immunoglobulin G; D010455:Peptides; D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins