ARTIFICIAL MOSAIC PROTEIN CONTAINING ANTIGENIC EPITOPES OF HEPATITIS-E VIRUS

A synthetic gene encoding an artificial polypeptide composed of antige nic epitopes of the hepatitis E virus (HEV) proteins was constructed f rom short oligodeoxyribonucleotides by using PCR. The polypeptide comp rises a mosaic of three antigenically active dominant regions from the protein encoded by open reading frame 2 (ORF2), one antigenically act ive region from the protein encoded by ORF3 of the Burmese HEV strain, and one antigenically active region from the protein encoded by ORF3 of the Mexican HEV strain. The mosaic protein was expressed in Escheri chia coli as a chimera with glutathione S-transferase or beta-galactos idase. Guinea pig sera containing antibodies to the corresponding HEV synthetic peptides were used to demonstrate by Western immunoblot anal ysis and enzyme immunoassay the presence and accessibility of all HEV- specific antigenic epitopes introduced into the mosaic protein. Both t he glutathione S-transferase and beta-galactosidase hybrid proteins we re analyzed by using a panel of human anti-HEV-positive and negative s era. The data obtained strongly indicate a diagnostic potential for th e mosaic protein.