Ia molecule-associated selectivity in T cell recognition of a 23-amino-acid peptide of lysozyme.
Ak- or Ek-restricted T cells, generated by immunization with a 23-amino-acid peptide of hen egg-white lysozyme (amino acid 74-96), showed a strict correlation between the minimal peptide determinant recognized and the Ia molecule restricting recognition. All Ak-restricted clones obtained from six independently derived lines recognized determinants contained within peptides 74-86, while Ek-restricted clones recognized determinants within 85-96. This correlation was true whether B10.A mice (Ak, Ek) were immunized with peptide 74-96 or with each of the two smaller peptides (74-86 or 85-96). Furthermore, a T cell response could be obtained to peptide 74-86, but not to peptide 85-96 in B10.A (4R) mice, which express only the Ak molecule. Thus, an Ia molecule-associated selectivity exists in the choice of T cell determinants even within this small 23-amino-acid peptide antigen. Significant differences were noted, however, in the boundaries of the minimal peptide determinants recognized within peptide 74-96 by Ak- or Ek-restricted T cells, in comparison to those recognized by Ab-restricted T cells. These results indicate that interaction of the same peptide with distinct Ia molecules results in recognition of unique aspects of the antigenic determinants by the T cell receptor.
D000818:Animals; D000939:Epitopes / Q000032:analysis*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D009113:Muramidase / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D009113:Muramidase