title: Characterization of antigenic domains and epitopes in the ORF3 protein of a Chinese isolate of avian hepatitis E virus.
abstract: Avian hepatitis E virus (HEV) is an emerging virus associated with the big liver and spleen disease or hepatitis-splenomegaly syndrome in chickens and subclinical infections by the virus are also common. The complete genome of avian HEV contains three open-reading frames (ORFs) in which ORF2 protein is part of virus particles and thus contains primary epitopes. Antigenic epitopes of avian HEV ORF2 protein have been described but those associated with the ORF3 have not. To analyze the antigenic domains and epitopes in the ORF3 protein of a Chinese isolate of avian HEV (CaHEV), we generated a series of antigens comprised of the complete ORF3 and also five truncated overlapping ORF3 peptides. The antibodies used in this study were mouse antisera and monoclonal antibodies against ORF3, positive chicken sera from Specific Pathogen Free chickens experimentally infected with CaHEV and clinical chicken sera. Using these antigens and antibodies, we identified three antigenic domains at amino acids (aa) 1-28, 55-74 and 75-88 in which aa 75-88 was a dominant domain. The dominant domain contained at least two major epitopes since field chickens infected with avian HEV produced antibodies against the domain and epitopes. These results provide useful information for future development of immunoassays for the diagnosis of avian HEV infection.
authors.affiliation: Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China; Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, China Ministry of Agriculture, Yangling, Shaanxi 712100, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhao
authors.forename: Ya-ni
authors.initials: YN
authors.lastname: Sun
authors.forename: Shou-bin
authors.initials: SB
authors.lastname: Hu
authors.forename: Xin-jie
authors.initials: XJ
authors.lastname: Wang
authors.forename: Yi-hong
authors.initials: YH
authors.lastname: Xiao
authors.forename: Walter H
authors.initials: WH
authors.lastname: Hsu
authors.forename: Shu-qi
authors.initials: SQ
authors.lastname: Xiao
authors.forename: Cheng-bao
authors.initials: CB
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Mu
authors.forename: Julian A
authors.initials: JA
authors.lastname: Hiscox
authors.forename: En-Min
authors.initials: EM
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002645:Chickens / Q000276:immunology / Q000821:virology; D002681:China; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D004926:Escherichia coli / Q000235:genetics; D052678:Hepevirus / Q000235:genetics* / Q000276:immunology*; D007106:Immune Sera / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000276:immunology; D017434:Protein Structure, Tertiary / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013047:Specific Pathogen-Free Organisms; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology*
chemical_list: D000939:Epitopes; D007106:Immune Sera; C400973:ORF3 protein, Hepatitis E virus; D010455:Peptides; D011994:Recombinant Proteins; D014764:Viral Proteins
keywords: Antigenic domain; Avian hepatitis E virus; Epitope; ORF3 protein