Peptides naturally presented by MHC class I molecules

Annu Rev Immunol. 1993;11:213-44. doi: 10.1146/annurev.iy.11.040193.001241.


MHC class I molecules are peptide receptors of stringent specificity which however still allow millions of different ligands. This is achieved by the following specificity characteristics summarized as allele specific peptide motifs: Peptides are of defined length, depending on the class I allele (either 8 or 9 residues; exceptions have been observed). Typically, 2 of the 8 or 9 positions are anchors that can only be occupied by a single amino acid residue, or by residues with closely related side chains. Location and characteristics of anchors vary with class I alleles. The C terminus of the peptide ligands is frequently an aliphatic or charged residue. Such allele-specific class I peptide ligand motifs, known so far for H-2Kd, Kb, Kk, Kkm1, Db, HLA-A*0201, A*0205, and B*2705, are useful to predict natural T cell epitopes. The latter can be determined by extraction from cells recognized by the T cell of interest. It is not known how the class I ligands are produced in the cell, although speculative models exist. The peptide specificity of class I molecules and experimental evidence indicate that T cells are tolerant to only a small fraction of the expressed genomic sequences and are not tolerant to the remainder. The function of class I molecules is to present a collection of self-peptide samples at the cell surface for surveillance by T cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Histocompatibility Antigens Class I* / genetics
  • Humans
  • Immune Tolerance
  • Mice
  • Molecular Sequence Data
  • Peptides / genetics
  • Peptides / immunology*
  • Peptides / metabolism
  • Protein Processing, Post-Translational / immunology


  • Histocompatibility Antigens Class I
  • Peptides