title: CTL recognition of a novel HLA-A*0201-binding peptide derived from glioblastoma multiforme tumor cells.
abstract: Genetic instability of tumor cells can result in translation of proteins that are out of frame, resulting in expression of neopeptides. These neopeptides are not self-proteins and therefore should be immunogenic. By eluting peptides from human glioblastoma multiforme (GBM) tumor cell surfaces and subjecting them to tandem mass spectrometry, we identified a novel peptide (KLWGLTPKVTPS) corresponding to a frameshift in the 3' beta-hydroxysteroid dehydrogenase type 7 (HSD3B7) gene. HLA-binding algorithms predicted that a 9-amino acid sequence embedded in this peptide would bind to HLA-A*0201. We confirmed this prediction using an HLA-A*0201 refolding assay followed by live cell relative affinity assays, but also showed that the 12-mer binds to HLA-A*0201. Based on the 9-mer sequence, optimized peptide ligands (OPL) were designed and tested for their affinities to HLA-A*0201 and their abilities to elicit anti-peptide and CTL capable of killing GBM in vitro. Wild-type peptides as well as OPL induced anti-peptide CTL as measured by IFN-γ ELISPOTS. These CTL also killed GBM tumor cells in chromium-51 release assays. This study reports a new CTL target in GBM and further substantiates the concept that rational design and testing of multiple peptides for the same T-cell epitope elicits a broader response among different individuals than single peptide immunization.
authors.affiliation: School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.
authors.forename: Cheryl E
authors.initials: CE
authors.lastname: Myers
authors.forename: Paul
authors.initials: P
authors.lastname: Hanavan
authors.forename: Kwasi
authors.initials: K
authors.lastname: Antwi
authors.forename: Daruka
authors.initials: D
authors.lastname: Mahadevan
authors.forename: A Jamal
authors.initials: AJ
authors.lastname: Nadeem
authors.forename: Laurence
authors.initials: L
authors.lastname: Cooke
authors.forename: Adrienne C
authors.initials: AC
authors.lastname: Scheck
authors.forename: Zachary
authors.initials: Z
authors.lastname: Laughrey
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Lake
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D005909:Glioblastoma / Q000235:genetics* / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D011375:Progesterone Reductase / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
chemical_list: C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D009842:Oligopeptides; D011375:Progesterone Reductase