title: The antigenic property of the H5N1 avian influenza viruses isolated in central China.
abstract: BACKGROUND
  Three influenza pandemics outbroke in the last century accompanied the viral antigen shift and drift, resulting in the change of antigenic property and the low cross protective ability of the existed antibody to the newly emerged pandemic virus, and eventually the death of millions of people. The antigenic characterizations of the viruses isolated in central China in 2004 and 2006-2007 were investigated in the present study.
  
  
  RESULTS
  Hemagglutinin inhibition assay and neutralization assay displayed differential antigenic characteristics of the viruses isolated in central China in two periods (2004 and 2006-2007). HA genes of the viruses mainly located in two branches in phylogeny analysis. 53 mutations of the deduced amino acids of the HA genes were divided into 4 patterns. Mutations in pattern 2 and 3 showed the main difference between viruses isolated in 2004 and 2006-2007. Meanwhile, most amino acids in pattern 2 and 3 located in the globular head of the HA protein, and some of the mutations evenly distributed at the epitope sites.
  
  
  CONCLUSIONS
  The study demonstrated that a major antigenic drift had occurred in the viruses isolated in central China. And monitoring the antigenic property should be the priority in preventing the potential pandemic of H5N1 avian influenza virus.
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agriculture University, Wuhan, P.R., China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zou
authors.forename: Jianjiang
authors.initials: J
authors.lastname: Ke
authors.forename: Jiping
authors.initials: J
authors.lastname: Zhu
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhou
authors.forename: Meilin
authors.initials: M
authors.lastname: Jin
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D000940:Antigenic Variation; D000956:Antigens, Viral / Q000032:analysis* / Q000276:immunology*; D001717:Birds; D002681:China; D005838:Genotype; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology* / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000821:virology*; D050505:Mutant Proteins / Q000235:genetics / Q000276:immunology; D020125:Mutation, Missense; D009500:Neutralization Tests; D010802:Phylogeny; D011200:Poultry; D017422:Sequence Analysis, DNA
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D050505:Mutant Proteins; C109963:hemagglutinin, avian influenza A virus