Her-2/neu altered peptide ligand-induced CTL responses: Implications for peptides with increased HLA affinity and T-cell-receptor interaction

Sara O. Dionne, Cheryl E. Myers, Margaret H. Smith, Douglas F. Lake

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

In this study, we developed two Her-2/neu-derived E75 altered peptide ligands (APLs) that demonstrate increased affinities for the HLA-A*0201 allele compared with wild-type E75 peptide. The APLs contain amino acids from E75(369-377), an immunodominant Her-2/nue-derived peptide, and preferred primary and auxiliary HLA-A*0201 molecule anchor residues previously identified from combinatorial peptide library screening with the recombinant molecule. CTL lines were generated against wild-type E75 peptide (KIFGS-LAFL) and APLs by multiple rounds of peptide stimulation of peripheral blood mononuclear cells (PBMCs) from HLA-A2+ antigen normal individuals. CTL lines raised on wild-type E75 peptide cross-reacted with APLs and similarly, CTL lines raised on APLs cross-reacted with wild-type E75 peptide, as measured by IFN-γ ELISpot and target cell lysis assays. One of five individuals demonstrated specificity for APL 2 (FLFGSLAFL), whereas APL 5 (FLFESLAFL)-specific responses were observed from all five individuals tested. Molecular models of the E75, APL 2, and APL 5/HLA-A2 complexes indicated that the substitution of glycine with glutamic acid at position four of APL 5 resulted in the presentation of a large, negatively charged side chain that interacts with the outer edge of the HLA-A2 antigen alpha helix and is freely available to interact with cognate T-cell receptors. The results of this study further substantiate the concept that rational design of T-cell epitopes may lead to stronger peptide immunogens than natural, wild-type peptides.

Original languageEnglish (US)
Pages (from-to)307-314
Number of pages8
JournalCancer Immunology, Immunotherapy
Volume53
Issue number4
DOIs
StatePublished - Apr 1 2004
Externally publishedYes

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Keywords

  • Altered peptide ligand (APL)
  • Cytotoxic T lymphocyte (CTL)
  • Her-2/neu
  • Human leukocyte antigen (HLA)
  • T-cell receptor (TCR)

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Oncology
  • Cancer Research

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