title: Discrimination of influenza A subtype by antibodies recognizing host-specific amino acids in the viral nucleoprotein.
abstract: BACKGROUND
  Nucleoprotein (NP) of influenza viruses is utilized to differentiate between the A, B, and C viral serotypes. The availability of influenza genome sequence data has allowed us to identify specific amino acids at particular positions in viral proteins, including NP, known as "signature residues," which can be used to discriminate human influenza A viruses from H5N1 highly pathogenic avian influenza in human cases (HPAI) and pandemic H1N1(2009) (H1N1/2009) viruses.
  
  
  METHODS
  Screening and epitope mapping of monoclonal antibodies (mAb) against NP of influenza A, which reacted differently with NP from human influenza A virus from HPAI and H1N1/2009 A virus. To identify the epitope(s) responsible for the discrimination of viral NP by mAbs, we prepared mutant NP proteins in the 293 cell expression system because some of the mAbs reacted with non-linear epitopes.
  
  
  CONCLUSIONS
  In the present study, we identified 3 mAbs. The results of epitope mapping showed that the epitopes were located at the signature residues. These results indicated that signature residues of NP could discriminate influenza A viruses from different origin.
authors.affiliation: Department of Infectious Diseases, National Center for Global Health and Medicine, Tokyo, Japan. takiyam@ri.ncgm.go.jp
authors.forename: Tohru
authors.initials: T
authors.lastname: Miyoshi-Akiyama
authors.forename: Tetsu
authors.initials: T
authors.lastname: Yamashiro
authors.forename: Le Quynh
authors.initials: le Q
authors.lastname: Mai
authors.forename: Kenji
authors.initials: K
authors.lastname: Narahara
authors.forename: Akitomo
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Shinagawa
authors.forename: Sunao
authors.initials: S
authors.lastname: Mori
authors.forename: Hirotake
authors.initials: H
authors.lastname: Kitajima
authors.forename: Teruo
authors.initials: T
authors.lastname: Kirikae
mesh_terms: D000596:Amino Acids / Q000276:immunology*; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes / Q000276:immunology*; D006801:Humans; D009980:Influenza A virus / Q000145:classification* / Q000276:immunology*; D019590:Nucleocapsid Proteins; D016601:RNA-Binding Proteins / Q000276:immunology*; D014758:Viral Core Proteins / Q000276:immunology*; D014773:Virology / Q000379:methods*
chemical_list: D000596:Amino Acids; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes; C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D016601:RNA-Binding Proteins; D014758:Viral Core Proteins