T cell epitope definition by differential mass spectrometry: identification of a novel, immunogenic HLA-B8 ligand directly from renal cancer tissue.
In this study, we describe a differential mass spectrometric technique for the immuno-proteomic analysis of the major histocompatibility complex (MHC) peptides of a renal cell carcinoma (RCC) biopsy compared with the healthy kidney tissue of the same patient after nephrectomy. Using a stable isotope labeling approach, we could directly compare and relatively quantify 43 MHC-peptide pairs, most of which were present in similar proportions on both normal kidney and tumor. Significantly, two dominant peptides of monoisotopic masses ([M+H](+)) 973.43 u and 967.59 u, respectively, were found exclusively in the tumor sample. One of these was identified as originating from heme oxygenase-1 (HO-1), a protein involved in induction of apoptosis resistance, immuno-suppression and neoangiogenesis and reported to be up-regulated in various cancer types. Moreover, the corresponding synthetic HO-1-derived peptide was shown to be immunogenic in vitro by generation of CD8+ T cell lines with peptide-specific cytolytic activity. Thus, this peptide is an example of a differentially identified T cell epitope that could be considered as a target for immunotherapy.
Flad
Thomas
T
Section for Transplantation Immunology and Immunohematology, University of Tuebingen, Waldhoernlestrasse 22, 72072 Tuebingen, Germany. thomas.flad@gmx.de
Mueller
Ludmila
L
Dihazi
Hassan
H
Grigorova
Veneta
V
Bogumil
Ralf
R
Beck
Alexander
A
Thedieck
Cornelia
C
Mueller
Gerhard A
GA
Kalbacher
Hubert
H
Mueller
Claudia A
CA
D000368:Aged; D002851:Chromatography, High Pressure Liquid; D000939:Epitopes / Q000737:chemistry*; D005260:Female; D015795:HLA-B8 Antigen / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000032:analysis; D007680:Kidney Neoplasms / Q000737:chemistry*; D008024:Ligands; D013058:Mass Spectrometry / Q000379:methods*; D036103:Nanotechnology; D013601:T-Lymphocytes / Q000276:immunology*
D000939:Epitopes; D015795:HLA-B8 Antigen; D008024:Ligands; D007371:Interferon-gamma