IDENTIFICATION OF HEPATITIS-G VIRUS-PARTICLES IN HUMAN SERUM BY E2-SPECIFIC MONOCLONAL-ANTIBODIES GENERATED BY DNA IMMUNIZATION

In order to elucidate the structure and morphology of hepatitis G viru s (HGV), a recently isolated flavivirus, we generated a panel of eight monoclonal antibodies (MAbs) against the putative second envelope pro tein (E2) following DNA immunization. The MAbs were shown to be specif ic for four different epitopes on recombinant E2. MAb Mc6 was the only antibody able to detect the linear epitope LTGGFYEPL. In addition, Mc 6 was able to immunoprecipitate viral particles in human blood samples as, detected by reverse transcription-PCR amplification of HGV RNA. T his precipitation could be competed by addition of saturating amounts of the linear peptide or abolished by addition of Nonidet P-40. We con clude that, albeit lacking the N-terminal sequence of a functional cor e protein, HGV builds classical viral particles displaying E2 envelope protein on their outer surfaces.