AN INDIAN STRAIN OF HEPATITIS-E VIRUS (HEV) - CLONING, SEQUENCE, AND EXPRESSION OF STRUCTURAL REGION AND ANTIBODY-RESPONSES IN SERA FROM INDIVIDUALS FROM AN AREA OF HIGH-LEVEL HEV ENDEMICITY

Hepatitis E virus (HEV) is responsible for a majority of sporadic and epidemic viral hepatitides in India and other developing countries. Ev en though the genomes of four geographically distinct strains of HEV h ave been cloned and sequenced, the Indian strain of HEV remains largel y uncharacterized, We have cloned and sequenced about 2.2 kb of the HE V genome constituting the structural region from an Indian strain of H EV. The nucleotide and amino acid sequences show a high degree of cons ervation with sequences from other HEV strains, Open reading frames (O RF) 2 and 3 were expressed in Escherichia coli as N-terminal hexahisti dine epitope fusions. The purified proteins were then used in an immun oblot assay to evaluate the antibody status in sera from individuals f rom an area of high-level HEV endemicity, The anti-ORF2 antibodies wer e found to be nonspecific and could not be correlated to clinical dise ase. The immunoglobulin M anti-ORF3 was found to be specific for the p resence of acute disease. The implications of these findings in HEV di agnosis and vaccine development are discussed.