H-2M3a violates the paradigm for major histoeompatibility complex class I peptide binding

Academic Article

Abstract

  • The major histocompatibility (MHC) class I-b molecule H-2M3a binds and presents N-formylated peptides to cytotoxic T lymphocytes. This requirement potentially places severe constraints on the number of peptides that M3a can present to the immune system. Consistent with this idea, the M3a-Ld MHC class I chimera is expressed at very low levels on the cell surface, but can be induced significantly by the addition of specific peptides at 27° Using this assay, we show that M3a binds many very short N-formyl peptides, including N-formyl chemotactic peptides and canonical octapeptides. This observation is in sharp contrast to the paradigmatic size range of peptides of 8-10 amino acids binding to most class I-a molecules and the class I-b molecule Qa-2. Stabilization by fMLF-benzyl amide could be detected at peptide concentrations as low as 100 nM. While N-formyl peptides as short as two amino acids in length stabilized expression of M3a-Ld, increasing the length of these peptides added to the stability of peptide-MHC complexes as determined by 27-37°C temperature shift experiments. We propose that relaxation of the length rule may represent a compensatory adaptation to maximize the number of peptides that can be presented by H-2M3a. © 1995, Rockefeller University Press., All rights reserved.
  • Authors

    Published In

    Digital Object Identifier (doi)

    Author List

  • Vyas JM; Rodgers JR; Rich RR
  • Start Page

  • 1817
  • End Page

  • 1825
  • Volume

  • 181
  • Issue

  • 5