TY - JOUR
T1 - Her-2/neu altered peptide ligand-induced CTL responses
T2 - Implications for peptides with increased HLA affinity and T-cell-receptor interaction
AU - Dionne, Sara O.
AU - Myers, Cheryl E.
AU - Smith, Margaret H.
AU - Lake, Douglas F.
N1 - Funding Information:
Acknowledgements We are grateful to Dr Sue Roberts for her contributions to the molecular modeling of HLA-A2/peptide complexes. This study was supported by a National Cancer Institute grant, RO1 CA94852.
PY - 2004/4
Y1 - 2004/4
N2 - 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.
AB - 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.
KW - Altered peptide ligand (APL)
KW - Cytotoxic T lymphocyte (CTL)
KW - Her-2/neu
KW - Human leukocyte antigen (HLA)
KW - T-cell receptor (TCR)
UR - http://www.scopus.com/inward/record.url?scp=1642276569&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1642276569&partnerID=8YFLogxK
U2 - 10.1007/s00262-003-0439-y
DO - 10.1007/s00262-003-0439-y
M3 - Article
C2 - 14605764
AN - SCOPUS:1642276569
SN - 0340-7004
VL - 53
SP - 307
EP - 314
JO - Cancer Immunology, Immunotherapy
JF - Cancer Immunology, Immunotherapy
IS - 4
ER -