title: Characterisation and haemagglutinin gene epitope mapping of a variant strain of H5N1 subtype avian influenza virus.
abstract: H5N1 avian influenza virus (AIV) undergoes rapid evolution, and its antigenicity needs to be constantly evaluated in order to update the vaccine strain. In this report, a clade 7.2 AIV isolate named A/Chicken/Huadong/4/2008 (DT) is identified. Antigenic analysis revealed that DT had a significant low cross-reactive HI titre with antiserum against a clade 7 representative AIV, A/Chicken/Shanxi/2/2006 (Re-4). Animal experiments demonstrated that the Re-4+Re-5 vaccine provided 80% protection against DT challenge in chickens. Antisera cross-reactivity showed that a mutant with a change of residues 129, 139, 140 in site A in the HA protein had reduced reactivity with DT antiserum and increased reactivity with Re-4 antiserum. Furthermore, residue Leu129 in site A of the HA protein was confirmed to be critical for maintenance of the reactivity with the DT antiserum, and Asn140, possessing a new glycosylation site, was confirmed to be critical for reducing reactivity with the Re-4 antiserum. These results imply that there is an antigenic drift within clade 7 viruses, and insertion and glycosylation of amino acid residues in site A of the HA protein may contribute to the antigenic variation.
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Quangang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Yinbiao
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China.
authors.forename: Sujuan
authors.initials: S
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China. Electronic address: daxinpeng@yahoo.com.
authors.forename: Daxin
authors.initials: D
authors.lastname: Peng
authors.affiliation: College of Veterinary Medicine, Ministry of Education Key Lab for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu 225009, PR China. Electronic address: xfliu@yzu.edu.cn.
authors.forename: Xiufan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002642:Chick Embryo; D002645:Chickens; D002522:Chlorocebus aethiops; D003429:Cross Reactions; D004285:Dogs; D004372:Ducks; D018604:Epitope Mapping; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D014774:Virulence
chemical_list: D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines