title: A cryptic vascular endothelial growth factor T-cell epitope: identification and characterization by mass spectrometry and T-cell assays.
abstract: Vascular endothelial growth factor (VEGF) is involved in various physiologic processes, such as angiogenesis or wound healing, but is also crucial in pathologic events, such as tumor growth. Thus, clinical anti-VEGF treatments have been developed that could already show beneficial effects for cancer patients. In this article, we describe the first VEGF-derived CD8(+) T-cell epitope. The natural HLA ligand SRFGGAVVR was identified by differential mass spectrometry in two primary renal cell carcinomas (RCC) and was significantly overpresented on both tumor tissues. SRFGGAVVR is derived from a cryptic translated region of VEGF presumably by initiation of translation at the nonclassic start codon CUG(499). SRFGGAVVR-specific T cells were generated in vitro using peptide-loaded dendritic cells or artificial antigen-presenting cells. SRFGGAVVR-specific CD8(+) T cells, identified by HLA tetramer analysis after in vitro stimulation, were fully functional T effector cells, which were able to secrete IFN-gamma on stimulation and killed tumor cells in vitro. Additionally, we have quantitatively analyzed VEGF mRNA and protein levels in RCC tumor and normal tissue samples by gene chip analysis, quantitative reverse transcription-PCR, in situ hybridization, and bead-based immunoassay. In the future, T cells directed against VEGF as a tumor-associated antigen may represent a possible way of combining peptide-based anti-VEGF immunotherapy with already existent anti-VEGF cancer therapies.
authors.affiliation: Department of Immunology, Institute for Cell Biology, University of Tübingen, Germany.
authors.forename: Andreas O
authors.initials: AO
authors.lastname: Weinzierl
authors.forename: Dominik
authors.initials: D
authors.lastname: Maurer
authors.forename: Florian
authors.initials: F
authors.lastname: Altenberend
authors.forename: Nicole
authors.initials: N
authors.lastname: Schneiderhan-Marra
authors.forename: Karin
authors.initials: K
authors.lastname: Klingel
authors.forename: Oliver
authors.initials: O
authors.lastname: Schoor
authors.forename: Dorothee
authors.initials: D
authors.lastname: Wernet
authors.forename: Thomas
authors.initials: T
authors.lastname: Joos
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Rammensee
authors.forename: Stefan
authors.initials: S
authors.lastname: Stevanović
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000235:genetics / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
chemical_list: D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; D010446:Peptide Fragments; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A