Epitopes described in "Antigenic switching of hepatitis B virus by alternative dimerization of the capsid protein."

Article Authors:Michael A DiMattia; Norman R Watts; Stephen J Stahl; Jonathan M Grimes; Alasdair C Steven; David I Stuart; Paul T Wingfield
Article Title:Antigenic switching of hepatitis B virus by alternative dimerization of the capsid protein.
Reference Detail
Reference ID:1025512
Abstract:Chronic hepatitis B virus (HBV) infection afflicts millions worldwide with cirrhosis and liver cancer. HBV e-antigen (HBeAg), a clinical marker for disease severity, is a nonparticulate variant of the protein (core antigen, HBcAg) that forms the building-blocks of capsids. HBeAg is not required for virion production, but is implicated in establishing immune tolerance and chronic infection. Here, we report the crystal structure of HBeAg, which clarifies how the short N-terminal propeptide of HBeAg induces a radically altered mode of dimerization relative to HBcAg (∼140° rotation), locked into place through formation of intramolecular disulfide bridges. This structural switch precludes capsid assembly and engenders a distinct antigenic repertoire, explaining why the two antigens are cross-reactive at the T cell level (through sequence identity) but not at the B cell level (through conformation). The structure offers insight into how HBeAg may establish immune tolerance for HBcAg while evading its robust immunogenicity.
Affiliations:Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Headington OX3 7BN, UK.
Reference Type:Literature
PubMed ID:23219881
Journal Volume:21
Article Pages:133-42
Journal ISSN:0969-2126
Article Chemical List:Capsid Proteins;Hepatitis B Core Antigens;Hepatitis B e Antigens;Protein Precursors
Article MeSH List:Capsid(ultrastructure); Capsid Proteins(chemistry; ultrastructure); Crystallography, X-Ray; Hepatitis B Core Antigens(chemistry); Hepatitis B e Antigens(chemistry); Hepatitis B virus(immunology; ultrastructure); Immune Evasion; Molecular Mimicry; Protein Multimerization; Protein Precursors(chemistry); Protein Structure, Quaternary; Protein Structure, Secondary
Curation Last Updated:2015-06-05 03:51:20