title: An amino acid substitution in the influenza A virus hemagglutinin associated with escape from recognition by human virus-specific CD4+ T-cells.
abstract: Influenza virus-specific CD4+ T-helper cells were cloned that recognized a virus strain isolated in 1981, but that failed to recognize more recent strains. The HLA-DR*1601-restricted epitope recognized was located in the hemagglutinin (HA(99-113)) and the naturally occurring A-->V substitution at position 106 was responsible for abrogating the recognition by HA(99-113)-specific CD4+ T-cells. This amino acid substitution was found in influenza A/H3N2 viruses that circulated between 1999 and 2005 and did not affect recognition by virus-specific antibodies. It was speculated that influenza viruses could evade recognition by virus-specific CD4+ T-cells, at least temporarily.
authors.affiliation: Department of Virology and Postgraduate School Molecular Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Eufemia G M
authors.initials: EG
authors.lastname: Berkhoff
authors.forename: Martina M
authors.initials: MM
authors.lastname: Geelhoed-Mieras
authors.forename: Marcel
authors.initials: M
authors.lastname: Jonges
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Smith
authors.forename: Ron A M
authors.initials: RA
authors.lastname: Fouchier
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: Guus F
authors.initials: GF
authors.lastname: Rimmelzwaan
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002999:Clone Cells; D004285:Dogs; D000939:Epitopes / Q000235:genetics; D019143:Evolution, Molecular; D006684:HLA-DR Antigens / Q000378:metabolism; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000276:immunology; D009980:Influenza A virus / Q000235:genetics* / Q000276:immunology*; D014162:Transfection
chemical_list: D000939:Epitopes; D006684:HLA-DR Antigens; D019267:Hemagglutinin Glycoproteins, Influenza Virus