Study sheds light on enigmatic HBV protein
Scientists from the NIH's National Institute of Arthritis and Musculoskeletal and Skin Diseases and the University of Oxford recently developed an antibody that binds to and forms a stable complex with the e-antigen of HBV. It marks the first time scientists have been able to view an assembled and stable version of the mysterious antigen.
HBV expresses three major clinical antigens that elicit an immune response, including the surface antigen, the core antigen and the e-antigen. While the surface antigen is used for HBV vaccinations and the core antigen is important for virus production, the e-antigen and its relationship to the core antigen has been a mystery for 30 years.
The researchers found that the e-antigen sub-unit has essentially the same fold as the core antigen sub-unit but it pairs into dimers in a completely different way. The e-antigen subu-nits are rotated 140 degrees relative to each other, which allows the protein to assemble and transform its antigenic character.
As scientists come to understand the e-antigen structure, research can be conducted to completely discover its role in HBV persistence. Future studies could result in new methods to prevent chronic liver infections.
Approximately 350 million people are chronically infected with HBV, of whom 620,000 die annually from HBV-related liver disease.