Expression of hepatitis E virus putative structural proteins in recombinant vaccinia viruses.

Hepatitis E virus (HEV) is a polyadenylated, positive-stranded RNA virus which is a major cause of enterically transmitted non-A, non-B hepatitis in many developing countries. The viral genome contains three different open reading frames (ORFs): ORF1, which is believed to encode nonstructural proteins, and ORF2 and ORF3, which are believed to encode structural proteins. The full-length putative structural proteins encoded by ORF2 and ORF3 of HEV have been cloned and expressed in recombinant vaccinia virus. Proteins encoded by ORF2 and ORF3 when expressed in vaccinia virus are recognized by pooled sera obtained from individuals with acute hepatitis E. Vaccinia-expressed viral gene products of HEV will have utility in characterizing the cell-mediated immune response to HEV.