Identification of destabilizing residues in HLA class II-selected bacteriophage display libraries edited by HLA-DM

Eur J Immunol. 1999 Feb;29(2):660-8. doi: 10.1002/(SICI)1521-4141(199902)29:02<660::AID-IMMU660>3.0.CO;2-I.

Abstract

HLA-DM (DM) functions as a peptide editor by catalyzing the release of class II-associated invariant chain peptides (CLIP) and other unstable peptides, thus supporting the formation of stable class II-peptide complexes for presentation. To investigate the general features that determine the DM susceptibility of HLA-DR1/peptide complexes, we generated a large DM-sensitive peptide repertoire from an M13 bacteriophage display library using a novel double selection protocol: we selected bacteriophage capable of binding to DR1 molecules and, subsequently, we enriched DR1-bound bacteriophage susceptible to elution by purified DM molecules. Sequence and mutational analyses of the DR1/DM double-selected peptides revealed that the amino acids Gly and Pro play a destabilizing role in the dissociation kinetics of DR1 ligands. This observation was confirmed also in natural peptide sequences such as CLIP 89-101, HA 307-319 and bovine collagen II (CII) 261-273. Our results demonstrate that DM susceptibility does not only depend on the number and nature of anchor residues, or the peptide length. Instead, less obvious sequence characteristics play a major role in the DM editing process and ultimately in the composition of peptide repertoires presented to T cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen Presentation / genetics
  • Antigen Presentation / immunology*
  • Bacteriophages
  • Cattle
  • HLA-D Antigens / genetics*
  • HLA-D Antigens / immunology*
  • Histocompatibility Antigens Class II / genetics
  • Histocompatibility Antigens Class II / immunology
  • Humans
  • Molecular Sequence Data
  • Peptide Library
  • Sequence Analysis

Substances

  • H2-M antigens
  • HLA-D Antigens
  • HLA-DM antigens
  • Histocompatibility Antigens Class II
  • Peptide Library