Characterization and mapping of a B-cell immunogenic domain in hepatitis C virus E2 glycoprotein using a yeast peptide library.
To identify conserved humoral antigenic determinants within the hepatitis C virus (HCV) envelope protein E2, we expressed a peptide library containing random short fragments of the HCV envelope in yeast. Clones were identified using a monospecific rabbit antibody to a region downstream of the E2 hypervariable region. The clones define the limits of two original antigenic domains: a major one (aa 493-576) and a minor one (aa 535-606). The major antigenic domain maps in a region that displays a high degree of homology within a (HCV) subtype (92-97.6% identity). Yeast-encoded determinants were characterized by Western blot analysis, N-glycosidase F digestion, and using a panel of synthetic peptides. The data suggest that the major antigenic domain contains at least two determinants, one of them mimicked by an 18-mer peptide (aa 514-531). ELISA and competitive inhibition assays demonstrated that: (1) the determinants appear subtype 1a-specific, (2) seroprevalence of antibody to the determinants is rather low (20.6%), and (3) donors show a heterologous response to the different determinants. Antibody response to the E2 determinants was studied in HCV-infected chimpanzees and post-transfusion-associated NANB hepatitis cases. The antibody response was found during chronic infection and may not be effective for virus clearance.
Mink
M A
MA
Laboratory of Virology and Parasitology, Lindsley F. Kimball Research Institute of the New York Blood Center, New York 10021.
Benichou
S
S
Madaule
P
P
Tiollais
P
P
Prince
A M
AM
Inchauspe
G
G
D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D001667:Binding, Competitive; D001782:Blood Donors; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D016174:Hepacivirus / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000097:blood; D006526:Hepatitis C / Q000276:immunology*; D018937:Hepatitis C Antibodies; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
D000939:Epitopes; D006508:Hepatitis Antibodies; D018937:Hepatitis C Antibodies; D010455:Peptides; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins