High-sensitivity HLA class I peptidome analysis enables a precise definition of peptide motifs and the identification of peptides from cell lines and patients' sera.

Abstract

The characterization of peptides bound to human leukocyte antigen (HLA) class I is of fundamental importance for understanding CD8+ T cell-driven immunological processes and for the development of immunomodulatory therapeutic strategies. However, until now, the mass spectrometric analysis of HLA-bound peptides has typically required billions of cells, still resulting in relatively few high-confidence peptide identifications. Capitalizing on the recent developments in mass spectrometry and bioinformatics, we have implemented a methodology for the efficient recovery of acid-eluted HLA peptides after purification with the pan-reactive antibody W6/32 and have identified a total of 27 862 unique peptides with high confidence (1% false discovery rate) from five human cancer cell lines. More than 93% of the identified peptides were eight to 11 amino acids in length and contained signatures that were in excellent agreement with published HLA binding motifs. Furthermore, by purifying soluble HLA class I complexes (sHLA) from sera of melanoma patients, up to 972 high-confidence peptides could be identified, including melanoma-associated antigens already described in the literature. Knowledge of the HLA class I peptidome should facilitate multiplex tetramer technology-based characterization of T cells, and allow the development of patient selection, stratification and immunomodulatory therapeutic strategies.

• Authors: Danilo Ritz, Andreas Gloger, Benjamin Weide, Claus Garbe, Dario Neri, Tim Fugmann
• Journal: Proteomics (Proteomics) Vol. 16 Issue 10 Pg. 1570-80 (05 2016) ISSN: 1615-9861 [Electronic] Germany
• PMID: 26992070 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical References

• Antigens, Neoplasm
• Biomarkers, Tumor
• Histocompatibility Antigens Class I
• Peptides

Topics

• Amino Acid Motifs
• Amino Acid Sequence
• Antigens, Neoplasm (blood)
• Biomarkers, Tumor (blood, isolation & purification)
• Case-Control Studies
• Consensus Sequence
• HEK293 Cells
• HL-60 Cells
• Histocompatibility Antigens Class I (physiology)
• Humans
• Melanoma (blood)
• Peptides (blood, isolation & purification)
• Protein Binding
• Protein Interaction Domains and Motifs
• Spondylitis, Ankylosing (blood)