Structural analysis of hepatitis B surface antigen by monoclonal antibodies.

Abstract

A method has been developed for the analysis of hepatitis B surface antigen (HBsAg) antigenic structure at the molecular level that creates "fingerprints" or "signatures" of various hepatitis B viral (HBV) strains. This technique employs high affinity IgM and IgG monoclonal antibodies (anti-HBs) directed against distinct and separate determinants on HBsAg. In performing this antigenic structural analysis, separate binding curves for different monoclonal anti-HBs are generated by measuring immunoreactivity in serial dilutions of HBsAg-positive serum by radioimmunoassay. Since the HBsAg concentration in serum is unknown, the binding profiles of groups of samples are aligned by an iterative least-squares procedure to generate the numerical signature characteristic of the viral strain. The numerical signatures are then displayed on a computer-graphic plot. The signature profiles of HBsAg subtypes are a true reflection of their antigenic structure, and in vertical and horizontal transmission studies the molecular characteristics of the viral epitopes are conserved. By signature analysis we found substantial antigenic heterogeneity among the ayw3 strain both in the U. S. and France, as well as in populations of the Far East and Africa. Populations in Ethiopia, Gambia, and the Philippines were infected with two antigenically distinct HBV strains. In some newly identified HBV strains, it was found that epitopes identified by some monoclonal antibodies were absent or substantially reduced, which suggested that a genetic mutation may have occurred. Thus this study suggests that there is far more antigenic heterogeneity in HBV than previously recognized. These variants are antigenically distinct from each other at the epitope level, and were heretofore unrecognized by polyvalent anti-HBsAg antibodies.

Molecular basis of hepatitis B virus serotype variations within the four major subtypes

“…The concept that there are at least nine different HBV serotypes is now widely accepted (Courouc6 et al, 1976;Wands et al, 1984;Ben-Porath et al, 1985;Swenson et al, 1991). The molecular mapping of the subdeterminants defining these serotypes is important for several reasons.…”

Characterization and Biological Properties of A Hepatitis B Virus Isolated From A Patient Without Hepatitis B Virus Serologic Markers

“…HBV accounts for most acute and chronic liver disease worldwide. We and others (1)(2)(3) have detected by monoclonal antibodies (MAbs) and recombinant DNA techniques HBV or related agents in HBsAgnegative patients with and without antibodies to HBsAg (anti-HBs), HBcAg (anti-HBc) and HBeAg (anti-HBe). These agents have been shown to be present in serum and liver and are capable of producing long incubation hepatitis infection in chimpanzees (4).…”

Rapid Differentiation of Soybean Mosaic Virus Isolates by Antigenic Signature Analysis

“…from that of BEN-PORATH et al (1985), was used to estimate the multiple response functions between dilution and In cpm bound in the antigen sample. This allowed signatures from different samples to be aligned independent of starting concentration of virus.…”