title: An immunogenic WT1-derived peptide that induces T cell response in the context of HLA-A*02:01 and HLA-A*24:02 molecules.
abstract: The Wilms' tumor oncogene protein (WT1) is a highly validated tumor antigen for immunotherapy. WT1-targeted immunotherapy has been extensively explored in multiple human trials in various cancers. However, clinical investigations using WT1 epitopes have generally focused on two peptides, HLA-restricted to HLA-A*02:01 or HLA-A*24:02. The goal of this study was to identify new epitopes derived from WT1, to expand the potential use of WT1 as a target of immunotherapy. Using computer-based MHC-binding algorithms andin vitrovalidation of the T cell responses specific for the identified peptides, we found that a recently identified HLA-A*24:02-binding epitope (239-247), NQMNLGATL (NQM), was also a strong CD8+T cell epitope for HLA-A*02:01 molecule. A peptide second position Q240L substitution (NLM) or Q240Y substitution (NYM), further enhanced the T cell responses in both HLA-A*02:01 positive and HLA-A*24:02 positive healthy donors. Importantly, T cells stimulated with the new analog peptides displayed heteroclitic cross-reactivity with the native NQM sequence and were able to kill HLA-matched WT1-positive tumor cell lines and primary leukemia blasts. In addition, longer native and heteroclitic HLA-DR.B1-binding peptides, comprising the nine amino acid NQM or NLM sequences, could induce T cell response that recognized the CD8+epitope NQM, suggesting the processing and the presentation by HLA-A*02:01 molecules of the CD8+T cell epitope embedded within it. Our studies suggest that the analog peptides NLM and NYM could be potential candidates for future immunotherapy targeting WT1 positive cancers in the context of HLA-A*02:01 and A*24:02 positive populations.
authors.affiliation: Molecular Pharmacology Program, Sloan Kettering Institute , New York, NY, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Dao
authors.affiliation: Molecular Pharmacology Program, Sloan Kettering Institute , New York, NY, USA.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Korontsvit
authors.affiliation: Molecular Pharmacology Program, Sloan Kettering Institute , New York, NY, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Zakhaleva
authors.affiliation: Molecular Pharmacology Program, Sloan Kettering Institute , New York, NY, USA.
authors.forename: Casey
authors.initials: C
authors.lastname: Jarvis
authors.affiliation: Department of Medicine, Memorial Sloan Kettering Cancer Center , New York, NY, USA.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Mondello
authors.affiliation: Molecular Pharmacology Program, Sloan Kettering Institute, New York, NY, USA; Weill Cornell Medicine, New York, NY, USA.
authors.forename: Claire
authors.initials: C
authors.lastname: Oh
authors.affiliation: Molecular Pharmacology Program, Sloan Kettering Institute, New York, NY, USA; Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Weill Cornell Medicine, New York, NY, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Scheinberg
keywords: Analog peptides; CTL response; WT1; cancer vaccines; immunotherapy