title: Molecular and functional analysis of tyrosinase-related protein (TRP)-2 as a cytotoxic T lymphocyte target in patients with malignant glioma.
abstract: Tyrosinase-related protein (TRP)-2 is an immunogenic antigen in melanoma. The authors sought to investigate whether TRP-2 could be a potential target for patients with malignant glioma. RT-PCR analysis demonstrated that TRP-2 was present in 51.2% of primary tumor cell lines derived from patients with glioblastoma multiforme (GBM). The percentage of TRP-2-6b, TRP-2-INT2, TRP-2-LT, and TRP-2-8b isoform expression in all tested GBM cells was 13.9%, 34.9%, 41.9%, and 39.5%, respectively. TRP-2 protein expression was detected in GBM cells and tumor tissues by Western blot and immunohistochemistry. In addition, an HLA-A2-restricted cytotoxic T cell clone that recognizes the TRP-2(180-188) peptide (SVYDFFVWL) specifically lysed the TRP-2 positive GBM cells in a HLA-A2 restricted manner. In addition, the level of TRP-2 mRNA expression, as determined by real-time quantitative RT-PCR, correlated with the level of CTL recognition as measured by IFN-gamma secretion (R = 0.90; p < 0.01). To further test the immunogenicity of TRP-2 in glioma, PBMCs from a healthy donor were primed in vitro using autologous dendritic cells (DCs) pulsed with irradiated GBM cells. These in vitro generated T cells specifically lysed T2 cells pulsed with TRP-2(180-188) peptide and TRP-2 positive GBM cell lines. Most importantly, TRP-2(180-188) specific CTL frequency in four patients' PBMC who were both HLA-A2 and TRP-2 positive was significantly (p < 0.01) increased, respectively, after vaccinations with DCs pulsed with autologous tumor lysate. The authors' studies demonstrate that TRP-2 could be a useful antigen target for monitoring or developing immunotherapeutic strategies for glioma patients.
authors.affiliation: Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA. Liug@cshs.org
authors.forename: Gentao
authors.initials: G
authors.lastname: Liu
authors.forename: Hung T
authors.initials: HT
authors.lastname: Khong
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Wheeler
authors.forename: John S
authors.initials: JS
authors.lastname: Yu
authors.forename: Keith L
authors.initials: KL
authors.lastname: Black
authors.forename: Han
authors.initials: H
authors.lastname: Ying
mesh_terms: D017398:Alternative Splicing; D015153:Blotting, Western; D016923:Cell Death; D002460:Cell Line; D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000378:metabolism; D003713:Dendritic Cells / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005091:Exons; D005909:Glioblastoma / Q000235:genetics; D005910:Glioma / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry; D007167:Immunotherapy / Q000379:methods; D007371:Interferon-gamma / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000235:genetics* / Q000502:physiology*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D020033:Protein Isoforms; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000201:enzymology*
chemical_list: D018076:DNA, Complementary; D010455:Peptides; D020033:Protein Isoforms; D012333:RNA, Messenger; D012313:RNA; D007371:Interferon-gamma; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase