Identification of wild-type and mutant p53 peptides binding to HLA-A2 assessed by a peptide loading-deficient cell line assay and a novel major histocompatibility complex class I peptide binding assay.
Mutations of the p53 gene are the most frequently observed genetic changes in human cancers; often leading to an overexpression of the wild-type (wt) p53 protein. Demonstrable T cell reactivity against tumor cells overexpressing wt or mutant p53-derived peptides could support the application of such epitopes in cancer immunotherapies. As the binding of peptide to MHC class I molecules is a prerequisite for antigen-specific T cell recognition, we evaluated the ability of wt and mutant p53 peptides to bind to HLA-A2.1 using two independent flow cytometry-based assay systems, the T2 major histocompatibility complex (MHC) class I peptide stabilization assay (stabilization assay) and the peptide-induced MHC class I reconstitution assay (reconstitution assay). The twenty selected wt sequences each conformed to the previously reported HLA-A2.1 peptide binding motif. Seven of the wt p53 and 2/13 mutant p53 peptides derived from the previously chosen wt peptides bound to HLA-A2.1 in both the stabilization and the reconstitution assays. An additional six wt and six mutant p53 peptides, presumably exhibiting lower affinity for HLA-A2.1, were identified only in the reconstitution assay. Those p53 peptides binding HLA-A2.1 may provide useful immunogens for the generation of HLA-A2.1-restricted cytolytic T lymphocytes in vitro and in vivo.
Stuber
G
G
Department of Tumor Biology, Karolinska Institute, Stockholm.
Leder
G H
GH
Storkus
W T
WT
Lotze
M T
MT
Modrow
S
S
Székely
L
L
Wolf
H
H
Klein
E
E
Kärre
K
K
Klein
G
G
D000595:Amino Acid Sequence; D002460:Cell Line; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology*; D011485:Protein Binding; D013329:Structure-Activity Relationship; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000276:immunology*
D015789:HLA-A2 Antigen; D010455:Peptides; D016159:Tumor Suppressor Protein p53