TY - JOUR
T1 - Secreted HLA recapitulates the immunopeptidome and allows in-depth coverage of HLA A*02
T2 - 01 ligands
AU - Scull, Katherine E.
AU - Dudek, Nadine L.
AU - Corbett, Alexandra J.
AU - Ramarathinam, Sri H.
AU - Gorasia, Dhana G.
AU - Williamson, Nicholas A.
AU - Purcell, Anthony W.
PY - 2012/6
Y1 - 2012/6
N2 - HLA molecules are cell-surface glycoproteins that present peptides, derived from intracellular protein antigens, for surveillance by T lymphocytes. Secreted HLA (sHLA) technology is a powerful approach for studying these peptides, since it facilitates large-scale production of HLA-bound peptides. We compared secreted and membrane-bound forms of HLA A2 in terms of intracellular trafficking and their bound peptide repertoire (termed the immunopeptidome). We demonstrate that sHLA and membrane bound HLA (mHLA) negotiate intracellular compartments with similar maturation kinetics. Moreover, mass spectrometry revealed a substantial overlap in the immunopeptidome was observed when HLA A2-bound peptides were purified from various sources of sHLA and mHLA. By combining machine based algorithms with manual validation, we identified 1266 non-redundant peptides. Analysis of these peptides revealed a number bearing post-translational modifications, although some of these may arise spontaneously others represent modifications performed within the cell that survive antigen processing. Peptides bearing some of these modifications have not previously been described for HLA ligands, therefore, this compendium of 1266 non-redundant peptide sequences adds greatly to the existing database of HLA A2 ligands. Peptides from all sources displayed comparable HLA A2 consensus binding motifs, peptide lengths, predicted HLA A2 binding affinities and putative source antigens. We conclude that sHLA is a valid and useful technique for studying the immunopeptidome.
AB - HLA molecules are cell-surface glycoproteins that present peptides, derived from intracellular protein antigens, for surveillance by T lymphocytes. Secreted HLA (sHLA) technology is a powerful approach for studying these peptides, since it facilitates large-scale production of HLA-bound peptides. We compared secreted and membrane-bound forms of HLA A2 in terms of intracellular trafficking and their bound peptide repertoire (termed the immunopeptidome). We demonstrate that sHLA and membrane bound HLA (mHLA) negotiate intracellular compartments with similar maturation kinetics. Moreover, mass spectrometry revealed a substantial overlap in the immunopeptidome was observed when HLA A2-bound peptides were purified from various sources of sHLA and mHLA. By combining machine based algorithms with manual validation, we identified 1266 non-redundant peptides. Analysis of these peptides revealed a number bearing post-translational modifications, although some of these may arise spontaneously others represent modifications performed within the cell that survive antigen processing. Peptides bearing some of these modifications have not previously been described for HLA ligands, therefore, this compendium of 1266 non-redundant peptide sequences adds greatly to the existing database of HLA A2 ligands. Peptides from all sources displayed comparable HLA A2 consensus binding motifs, peptide lengths, predicted HLA A2 binding affinities and putative source antigens. We conclude that sHLA is a valid and useful technique for studying the immunopeptidome.
KW - Epitope discovery
KW - Immunopeptidome
KW - Mass spectrometry
KW - Peptide binding motif
KW - Secreted HLA
UR - http://www.scopus.com/inward/record.url?scp=84860371053&partnerID=8YFLogxK
U2 - 10.1016/j.molimm.2012.02.117
DO - 10.1016/j.molimm.2012.02.117
M3 - Article
C2 - 22424782
AN - SCOPUS:84860371053
SN - 0161-5890
VL - 51
SP - 136
EP - 142
JO - Molecular Immunology
JF - Molecular Immunology
IS - 2
ER -