title: An analogue peptide from the Cancer/Testis antigen PASD1 induces CD8+ T cell responses against naturally processed peptide.
abstract: We have previously identified the novel Cancer/Testis antigen PASD1 by immunoscreening a testis library with pooled acute myeloid leukemia (AML) patient sera. To develop a cytotoxic T lymphocyte (CTL)-inducing vaccine, we have now investigated the carboxy-terminal region, known to contain serological determinants, for MHC class I (HLA-A⋆0201)-binding peptides. Algorithm-selected natural peptides failed to show detectable HLA-A⋆0201 binding in T2 assays. However, anchor-modified analogue peptides showed enhanced binding, with decreased off-rates. Analogue peptide-loaded antigen-presenting cells (APCs) induced IFN-γ production by T cells from normal donors and patients. In addition, peptide-specific T cells could be expanded from cancer patients by stimulation with the PASD1 analogue peptide Pa14. For clinical application, a DNA fusion gene vaccine encoding Pa14 was designed and tested in "humanized" mice. Splenocytes from vaccinated mice showed in vitro cytotoxicity against tumour cells, either exogenously loaded with the corresponding wild-type peptide (Pw8) or expressing endogenously processed PASD1 protein. We show for the first time that a DNA vaccine encoding an altered PASD1 epitope can induce CTLs to target the natural peptide expressed by human tumour cells.
authors.affiliation: Department of Haematological Medicine, King's College London School of Medicine, The Rayne Institute, London, United Kingdom.
authors.forename: Nicola
authors.initials: N
authors.lastname: Hardwick
authors.forename: Sarah
authors.initials: S
authors.lastname: Buchan
authors.forename: Wendy
authors.initials: W
authors.lastname: Ingram
authors.forename: Ghazala
authors.initials: G
authors.lastname: Khan
authors.forename: Gisella
authors.initials: G
authors.lastname: Vittes
authors.forename: Jason
authors.initials: J
authors.lastname: Rice
authors.forename: Karen
authors.initials: K
authors.lastname: Pulford
authors.forename: Ghulam
authors.initials: G
authors.lastname: Mufti
authors.forename: Freda
authors.initials: F
authors.lastname: Stevenson
authors.forename: Barbara-ann
authors.initials: BA
authors.lastname: Guinn
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology* / Q000378:metabolism; D034961:Antigens, Nuclear / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology / Q000494:pharmacology; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D000939:Epitopes / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007167:Immunotherapy; D008297:Male; D051379:Mice; D010455:Peptides / Q000276:immunology / Q000494:pharmacology
chemical_list: D000951:Antigens, Neoplasm; D034961:Antigens, Nuclear; D019496:Cancer Vaccines; D000939:Epitopes; C515845:PASD1 protein, human; D010455:Peptides
keywords: DNA vaccine; PASD1; acute myeloid leukemia; analogue peptide; immunotherapy