title: Glycosylation of a synthetic peptide representing a T-cell determinant of influenza virus hemagglutinin results in loss of recognition by CD4+ T-cell clones.
abstract: Synthetic glycopeptides were used to study possible mechanisms for the reduction observed in the response of influenza virus-specific CD4+ T-cells to strains of virus in which amino acid substitution in the hemagglutinin has led to attachment of a carbohydrate side chain. The peptide NCTLIDALLGDPH stimulates vigorous proliferation of hemagglutinin-specific T-cell clones F1-36 and F1-40 but addition of a heptasaccharide, which approaches the size of natural carbohydrate antennae, eliminated the stimulatory capacity of the peptide. This occurs even though the site of carbohydrate attachment at the N-terminal asparagine lies outside the T-cell determinants encompassed by this sequence. A glycopeptide with only two sugar units was stimulatory for F1-36 but not F1-40, suggesting that peptides with a carbohydrate side chain are able to bind to MHC molecules but that approach of the T-cell receptor of certain clones to the glycopeptide-MHC complex is hindered. Loss of T-cell recognition following attachment of a long carbohydrate side-chain to T-cell determinants is not a general finding because attachment of six carbohydrate units to the peptide, NKYVKQNTLKLA, had little or no effect on the stimulation of a T-cell clone specific for this sequence.
authors.affiliation: Department of Microbiology, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: D C
authors.initials: DC
authors.lastname: Jackson
authors.forename: H E
authors.initials: HE
authors.lastname: Drummer
authors.forename: L
authors.initials: L
authors.lastname: Urge
authors.forename: L
authors.initials: L
authors.lastname: Otvos
authors.forename: L E
authors.initials: LE
authors.lastname: Brown
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002999:Clone Cells; D006020:Glycopeptides / Q000138:chemical synthesis / Q000276:immunology*; D006031:Glycosylation; D006389:Hemagglutinins, Viral / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D009980:Influenza A virus / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data
chemical_list: D000914:Antibodies, Viral; D006020:Glycopeptides; D006389:Hemagglutinins, Viral