A single amino acid substitution in influenza hemagglutinin abrogates recognition by monoclonal antibody and a spectrum of subtype-specific L3T4+ T cell clones.
A fine specificity analysis of influenza hemagglutinin-specific IAk-restricted T cell clones using natural virus variants of the H3N2 subtype, monoclonal antibody-selected variants and a synthetic peptide corresponding to a variable region of the HA1 polypeptide has provided insight on the structural basis for T cell recognition. A glycine to arginine substitution at HA1 135 abrogates recognition by a panel of T cell clones which, according to their reactivity for natural virus variants, have different antigenic specificities: three clones recognize a synthetic peptide (HA1 residues 118-138) but fail to recognize the monoclonal antibody-selected mutant (Gly135/Arg). There is no correlation, however, between differences in T cell specificity for the natural virus variants and HA1 amino acid sequences in this region. Two further clones have a reduced proliferative response to mutant recognize a completely different spectrum of natural variants, and only one of these clones recognizes the synthetic peptide. We speculate that influenza hemagglutinin employs a common strategy during antigenic drift to evade antibody recognition and effective processing/presentation to subtype-specific T cell clones.
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D005998:Glycine; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000235:genetics / Q000276:immunology*; D009980:Influenza A virus / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008808:Mice, Inbred CBA; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D010446:Peptide Fragments; D005998:Glycine