title: Tumor antigen-specific T cells for immune monitoring of dendritic cell-treated glioblastoma patients.
abstract: CD8(+) T cells are part of the adaptive immune system and, as such, are responsible for the elimination of tumor cells. Dendritic cells (DC) are professional antigen-presenting cells (APC) that activate CD8(+) T cells. Effector CD8(+) T cells in turn mediate the active immunotherapeutic response of DC vaccination against the aggressive glioblastoma (GBM). The lack of tumor response assays complicates the assessment of treatment success in GBM patients.
  
  
  
  A novel assay to identify specific cytotoxicity of activated T cells by APC was evaluated. Tumor antigen-pulsed DCs from HLA-A*02-positive GBM patients were cultivated to stimulate autologous cytotoxic T lymphocytes (CTL) over a 12-day culture period. To directly correlate antigen specificity and cytotoxic capacity, intracellular interferon (IFN)-γ fluorescence flow cytometry-based measurements were combined with anti-GBM tumor peptide dextramer staining. IFN-γ response was quantified by real-time polymerase chain reaction (PCR), and selected GBM genes were compared with healthy human brain cDNA by single specific primer PCR characterization.
  
  
  
  Using CTL of GBM patients stimulated with GBM lysate-pulsed DCs increased IFN-γ messenger RNA levels, and intracellular IFN-γ protein expression was positively correlated with specificity against GBM antigens. Moreover, the GBM peptide-specific CD8(+) T-cell response correlated with specific GBM gene expression. Following DC vaccination, GBM patients showed 10-fold higher tumor-specific signals compared with unvaccinated GBM patients.
  
  
  
  These data indicate that GBM tumor peptide-dextramer staining of CTL in combination with intracellular IFN-γ staining may be a useful tool to acquire information on whether a specific tumor antigen has the potential to induce an immune response in vivo.
authors.affiliation: Institute of Clinical Hemostaseology and Transfusion Medicine, Saarland University Medical Center, Homburg, Germany. Electronic address: isabelle.mueller@uks.eu.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Müller
authors.affiliation: Institute of Clinical Hemostaseology and Transfusion Medicine, Saarland University Medical Center, Homburg, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Altherr
authors.affiliation: Stem Cell Laboratory, University Children's Hospital, University of Würzburg, Würzburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Eyrich
authors.affiliation: Immungenetic/HLA, German Red Cross Blood Service, Bad Kreuznach, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Flesch
authors.affiliation: Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University School of Medicine, Homburg, Germany.
authors.forename: Kim S
authors.initials: KS
authors.lastname: Friedmann
authors.affiliation: Department of Neurosurgery, Saarland University Medical Center, Homburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Ketter
authors.affiliation: Department of Neurosurgery, Saarland University Medical Center, Homburg, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Oertel
authors.affiliation: Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University School of Medicine, Homburg, Germany.
authors.forename: Eva C
authors.initials: EC
authors.lastname: Schwarz
authors.affiliation: Stem Cell Laboratory, University Children's Hospital, University of Würzburg, Würzburg, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Technau
authors.affiliation: Department of Neurosurgery, Saarland University Medical Center, Homburg, Germany.
authors.forename: Steffi
authors.initials: S
authors.lastname: Urbschat
authors.affiliation: Institute of Clinical Hemostaseology and Transfusion Medicine, Saarland University Medical Center, Homburg, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Eichler
mesh_terms: D000951:Antigens, Neoplasm / Q000276:immunology; D001932:Brain Neoplasms / Q000235:genetics / Q000276:immunology* / Q000628:therapy; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D064987:Cell- and Tissue-Based Therapy / Q000379:methods*; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005909:Glioblastoma / Q000235:genetics / Q000276:immunology* / Q000628:therapy; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D015166:Monitoring, Immunologic / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D007371:Interferon-gamma
keywords: CD8(+) T cells; GBM peptides; IFN-γ; cancer immunotherapy; dextramer staining; immune monitoring