title: ELISA for IgG-class antibody to hepatitis E virus based on a highly conserved, conformational epitope expressed in Escherichia coli.
abstract: In assays based on most recombinant hepatitis E virus (HEV) antigens, the IgG antibody responses to HEV are observed commonly to wane or disappear after the acute phase of infection. Such IgG assays have therefore been used for the diagnosis of acute HEV infection, but they have limited usefulness in seroepidemiological studies. Using western immunoblotting, it was shown previously that the open reading frame (ORF) 2.1 antigen, representing the carboxy-terminal 267 amino acids (aa) of the capsid protein, exposes a conformational epitope which allows optimal detection of convalescent antibody compared to other proteins expressed in Escherichia coli. This conformational epitope is shown to be highly conserved between divergent human HEV isolates, and the development of a sensitive and highly specific enzyme immunoassay (ELISA) based on this recombinant antigen is described. The ORF2.1 ELISA allows the detection and quantitation of both acute- and convalescent phase HEV-specific IgG, and will help to define better the antibody responses to the virus and the prevalence of HEV infection worldwide.
authors.affiliation: Hepatitis Research Unit, Macfarlane Burnet Centre for Medical Research, Victoria, Australia. anderson@burnet.edu.au
authors.forename: D A
authors.initials: DA
authors.lastname: Anderson
authors.forename: F
authors.initials: F
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Riddell
authors.forename: T
authors.initials: T
authors.lastname: Howard
authors.forename: H F
authors.initials: HF
authors.lastname: Seow
authors.forename: J
authors.initials: J
authors.lastname: Torresi
authors.forename: G
authors.initials: G
authors.lastname: Perry
authors.forename: D
authors.initials: D
authors.lastname: Sumarsidi
authors.forename: S M
authors.initials: SM
authors.lastname: Shrestha
authors.forename: I L
authors.initials: IL
authors.lastname: Shrestha
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000956:Antigens, Viral / Q000096:biosynthesis* / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D017124:Conserved Sequence / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000939:Epitopes / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D016752:Hepatitis E virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000276:immunology; D011487:Protein Conformation; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000302:isolation & purification
chemical_list: D000956:Antigens, Viral; D000939:Epitopes; D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins