Franziska Blaeschke1, Milan Cedric Paul1, Martin Ulrich Schuhmann2, Armin Rabsteyn3, Christopher Schroeder4, Nicolas Casadei4, Jakob Matthes4, Christopher Mohr5, Ramin Lotfi6, Beate Wagner7, Theresa Kaeuferle1, Judith Feucht8, Semjon Willier1, Rupert Handgretinger3, Stefan StevanoviĆ9, Peter Lang3, Tobias Feuchtinger10. 1. Dr. von Hauner Children's Hospital University Hospital, Ludwig Maximilian University Munich, Munich, Germany. 2. Division of Pediatric Neurosurgery, Department of Neurosurgery, University Hospital Tübingen, Tübingen, Germany. 3. Department of General Pediatrics, Hematology/Oncology, University Children's Hospital, Tübingen, Germany. 4. Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany. 5. Quantitative Biology Center (QBiC), University of Tübingen, Tübingen, Germany; Institute for Translational Bioinformatics, University Hospital Tübingen, Tübingen, Germany. 6. Institute for Transfusion Medicine, University Hospital Ulm, Ulm, Germany; Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Services Baden-Württemberg-Hessen, Ulm, Germany. 7. Department of Transfusion Medicine and Hemostaseology, University Hospital Munich, Ludwig Maximilian University Munich, Munich, Germany. 8. Department of General Pediatrics, Hematology/Oncology, University Children's Hospital, Tübingen, Germany; Memorial Sloan Kettering Cancer Center, Center for Cell Engineering, New York, New York, USA. 9. Institute for Cell Biology, Department of Immunology, University of Tübingen, Tübingen, Germany. 10. Dr. von Hauner Children's Hospital University Hospital, Ludwig Maximilian University Munich, Munich, Germany. Electronic address: tobias.feuchtinger@med.uni-muenchen.de.
Abstract
BACKGROUND: Medulloblastoma is the most common malignant brain tumor in childhood and adolescence. Although some patients present with distinct genetic alterations, such as mutated TP53 or MYC amplification, pediatric medulloblastoma is a tumor entity with minimal mutational load and low immunogenicity. METHODS: We identified tumor-specific mutations using next-generation sequencing of medulloblastoma DNA and RNA derived from primary tumor samples from pediatric patients. Tumor-specific mutations were confirmed using deep sequencing and in silico analyses predicted high binding affinity of the neoantigen-derived peptides to the patients' human leukocyte antigen molecules. Tumor-specific peptides were synthesized and used to induce a de novo T-cell response characterized by interferon gamma and tumor necrosis factor alpha release of CD8+ cytotoxic T cells in vitro. RESULTS: Despite low mutational tumor burden, at least two immunogenic tumor-specific peptides were identified in each patient. T cells showed a balanced CD4/CD8 ratio and mostly effector memory phenotype. Induction of a CD8-specific T-cell response was achieved for the neoepitopes derived from Histidine Ammonia-Lyase (HAL), Neuraminidase 2 (NEU2), Proprotein Convertase Subtilisin (PCSK9), Programmed Cell Death 10 (PDCD10), Supervillin (SVIL) and tRNA Splicing Endonuclease Subunit 54 (TSEN54) variants. CONCLUSION: Detection of patient-specific, tumor-derived neoantigens confirms that even in tumors with low mutational load a molecular design of targets for specific T-cell immunotherapy is possible. The identified neoantigens may guide future approaches of adoptive T-cell transfer, transgenic T-cell receptor transfer or tumor vaccination.
BACKGROUND:Medulloblastoma is the most common malignant brain tumor in childhood and adolescence. Although some patients present with distinct genetic alterations, such as mutated TP53 or MYC amplification, pediatric medulloblastoma is a tumor entity with minimal mutational load and low immunogenicity. METHODS: We identified tumor-specific mutations using next-generation sequencing of medulloblastoma DNA and RNA derived from primary tumor samples from pediatric patients. Tumor-specific mutations were confirmed using deep sequencing and in silico analyses predicted high binding affinity of the neoantigen-derived peptides to the patients' human leukocyte antigen molecules. Tumor-specific peptides were synthesized and used to induce a de novo T-cell response characterized by interferon gamma and tumornecrosis factor alpha release of CD8+ cytotoxic T cells in vitro. RESULTS: Despite low mutational tumor burden, at least two immunogenic tumor-specific peptides were identified in each patient. T cells showed a balanced CD4/CD8 ratio and mostly effector memory phenotype. Induction of a CD8-specific T-cell response was achieved for the neoepitopes derived from Histidine Ammonia-Lyase (HAL), Neuraminidase 2 (NEU2), Proprotein Convertase Subtilisin (PCSK9), Programmed Cell Death 10 (PDCD10), Supervillin (SVIL) and tRNA Splicing Endonuclease Subunit 54 (TSEN54) variants. CONCLUSION: Detection of patient-specific, tumor-derived neoantigens confirms that even in tumors with low mutational load a molecular design of targets for specific T-cell immunotherapy is possible. The identified neoantigens may guide future approaches of adoptive T-cell transfer, transgenic T-cell receptor transfer or tumor vaccination.
Authors: Jacob S Rozowsky; Joyce I Meesters-Ensing; Julie A S Lammers; Muriël L Belle; Stefan Nierkens; Mariëtte E G Kranendonk; Lennart A Kester; Friso G Calkoen; Jasper van der Lugt Journal: Front Immunol Date: 2022-04-07 Impact factor: 8.786