FIG. 1.

(A) HBV map. The partially double-stranded 3.2-kb open circular genome present in circulating virions is shown at the center. The coding regions of viral capsid (C), secreted precore proteins (PC), POL, the large (L), middle (M), and small (S) ENV proteins, and the X protein are shown. The ENV-specific CTL epitope ENV28 (IPQSLDSWWTSL[○]) and POL-specific CTL epitope POL140 (HYFQTRHYL]▵]) are indicated. (B) Map of vectors used in this study. The POL fragment (POL/ENV) was subcloned under the control of the cytomegalovirus promoter or vaccinia virus promoter. The entire HBV ENV transcription unit is contained within the POL transcription unit. Note that the POL ORF contains the entire HBV ENV transcription unit and that the POL expression vectors have the capacity to produce both POL and ENV proteins of HBV.