Recognition of core and flanking amino acids of MHC class II-bound peptides by the T cell receptor

Publisher Website
Google Scholar
Abstract
CD4 T cells recognize peptides bound to major histocompatibility complex (MHC) class II molecules. Most MHC class II molecules have four binding pockets occupied by amino acids 1, 4, 6, and 9 of the minimal peptide epitope, while the residues at positions 2, 3, 5, 7, and 8 are available to interact with the T cell receptor (TCR). In addition MHC class II bound peptides have flanking residues situated outside of this peptide core. Here we demonstrate that the flanking residues of the conalbumin peptide bound to I‐Ak have no effect on recognition by the D10 TCR. To study therole of peptide flanks for recognition by a second TCR, we determined the MHC and TCR contacting amino acids of the I‐Ab bound Eα peptide. The Eα peptide is shown to bind I‐Ab using four alanines as anchor residues. TCR recognition of Eα peptides with altered flanking residues again suggested that, in general, no specific interactions occurred with the peptide flanks. However, using an HLA‐DM‐mediated technique to measure peptide binding to MHC class II molecules, we found that the peptide flanking residues contribute substantially to MHC binding.

This publication has 0 references indexed in Scilit: