Analysis of the requirements for class II-restricted T Cell Recognition of a single determinant reveals considerable diversity in the T cell response and degeneracy of peptide binding to I-Ed

Abstract

The amino acid sequences recognized by five I-Ed-restricted and one EαAβd-restricted murine T cell clones were determined. The clones had been raised to a synthetic peptide representing amino acids 305-328 of influenza virus hemagglutinin. It was found that although all of the T cell clones recognized a single 10-residue region of the peptide, 307KYVKQNTLKL316, different clones could recognize minimal ("core") determinants spanning 8, 9, or 10 of these amino acids. To see whether particular amino acids within the sequence 307-316 were universally important for T cell recognition, the six clones were assayed for their ability to tolerate single amino acid substitutions of the 10 residue pepti..