Premium
Varying abilities of recombinant polypeptides from different regions of hepatitis E virus ORF2 and ORF3 to detect anti‐HEV immunoglobulin M
Author(s) -
Ma Hongxia,
Song Xiaoguo,
Li Zhuo,
Harrison Tim J.,
Zhang Heqiu,
Huang Weijin,
Hao Wa,
Kong Wei,
Wang Youchun
Publication year - 2009
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.21484
Subject(s) - hepatitis e virus , virology , orfs , biology , genotype , antibody , recombinant dna , epitope , hepatitis e , caliciviridae , virus , open reading frame , microbiology and biotechnology , gene , peptide sequence , viral disease , genetics
Following infection with hepatitis E virus (HEV), anti‐HEV immunoglobulin (Ig) M is thought to develop before anti‐HEV IgG and to be a better marker for differentiating between the acute and convalescent phases of infection. In order to select polypeptides for improved detection of anti‐HEV IgM, six and three overlapping polypeptides from open reading frames (ORFs) 2 and 3, respectively, of HEV genotypes 1 and 4 were expressed as fusion proteins in Escherichia coli . The reactivities of the polypeptides with anti‐HEV IgM were evaluated using immunoblotting and enzyme immunoassays (EIAs). The data indicated that polypeptides from the N‐terminus of ORF3 and middle region of ORF2 were weakly or not reactive with anti‐HEV IgM, while those from the remaining regions of ORF2 and ORF3 contained reactive epitopes. Anti‐HEV IgM against the N‐ or C‐terminus of ORF2 appeared earlier and disappeared faster than that against polypeptides from the C‐terminus of ORF3, based on serum samples from rhesus monkeys infected experimentally, and from patients infected naturally, with HEV. The N‐ and C‐terminal polypeptides from ORF2 complemented one another in detecting anti‐HEV IgM and EIA sensitivity was improved significantly with a combination of these polypeptides. The reactivities of ORF2 polypeptides from genotypes 1 and 4 were similar but that of ORF3 differed with sera from monkeys infected by the two genotypes. Thus, a combination of N‐ and C‐terminal polypeptides of ORF2 from one genotype may be effective in EIAs to detect anti‐HEV IgM. J. Med. Virol. 81:1052–1061, 2009. © 2009 Wiley‐Liss, Inc.