ELISA FOR ANTIBODY TO HEPATITIS-E VIRUS (HEV) BASED ON COMPLETE OPEN-READING FRAME-2 PROTEIN EXPRESSED IN INSECT CELLS - IDENTIFICATION OF HEV INFECTION IN PRIMATES

A recombinant baculovirus containing the complete open-reading frame ( ORF)-2 region of the hepatitis E virus (HEV) genome was constructed. T he major protein synthesized in insect cells infected with recombinant virus was about the size expected for the complete ORF-2 product. Thi s protein reacted in a Western blot assay with plasma from an HEV-infe cted chimpanzee. Lysates of the recombinant virus-infected insect cell s were used in ELISA to monitor seroconversion of eight primate specie s (chimpanzees, four species of Old World monkeys, and three species o f New World monkeys) inoculated with HEV. Homologous detector anti-imm unoglobulin was more sensitive than heterologous anti-immunoglobulin f or detecting anti-HEV by ELISA. All primate species except tamarins se roconverted after inoculation with HEV, although anti-HEV titers of Ol d World monkey species were generally higher than those of New World m onkey species. The ELISA with complete ORF-2 antigen appeared to be a sensitive and practical method for detecting anti-HEV.