@article{MarcuSchlosserKeuppetal.2021, author = {Marcu, Ana and Schlosser, Andreas and Keupp, Anne and Trautwein, Nico and Johann, Pascal and W{\"o}lfl, Matthias and Lager, Johanna and Monoranu, Camelia Maria and Walz, Juliane S and Henkel, Lisa M and Krauß, J{\"u}rgen and Ebinger, Martin and Schuhmann, Martin and Thomale, Ulrich Wilhelm and Pietsch, Torsten and Klinker, Erdwine and Schlegel, Paul G and Oyen, Florian and Reisner, Yair and Rammensee, Hans-Georg and Eyrich, Matthias}, title = {Natural and cryptic peptides dominate the immunopeptidome of atypical teratoid rhabdoid tumors}, series = {Journal for ImmunoTherapy of Cancer}, volume = {9}, journal = {Journal for ImmunoTherapy of Cancer}, doi = {10.1136/jitc-2021-003404}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-370214}, year = {2021}, abstract = {Background Atypical teratoid/rhabdoid tumors (AT/RT) are highly aggressive CNS tumors of infancy and early childhood. Hallmark is the surprisingly simple genome with inactivating mutations or deletions in the SMARCB1 gene as the oncogenic driver. Nevertheless, AT/RTs are infiltrated by immune cells and even clonally expanded T cells. However, it is unclear which epitopes T cells might recognize on AT/RT cells. Methods Here, we report a comprehensive mass spectrometry (MS)-based analysis of naturally presented human leukocyte antigen (HLA) class I and class II ligands on 23 AT/RTs. MS data were validated by matching with a human proteome dataset and exclusion of peptides that are part of the human benignome. Cryptic peptide ligands were identified using Peptide-PRISM. Results Comparative HLA ligandome analysis of the HLA ligandome revealed 55 class I and 139 class II tumor-exclusive peptides. No peptide originated from the SMARCB1 region. In addition, 61 HLA class I tumor-exclusive peptide sequences derived from non-canonically translated proteins. Combination of peptides from natural and cryptic class I and class II origin gave optimal representation of tumor cell compartments. Substantial overlap existed with the cryptic immunopeptidome of glioblastomas, but no concordance was found with extracranial tumors. More than 80\% of AT/RT exclusive peptides were able to successfully prime CD8+ T cells, whereas naturally occurring memory responses in AT/RT patients could only be detected for class II epitopes. Interestingly, >50\% of AT/RT exclusive class II ligands were also recognized by T cells from glioblastoma patients but not from healthy donors. Conclusions These findings highlight that AT/RTs, potentially paradigmatic for other pediatric tumors with a low mutational load, present a variety of highly immunogenic HLA class I and class II peptides from canonical as well as non-canonical protein sources. Inclusion of such cryptic peptides into therapeutic vaccines would enable an optimized mapping of the tumor cell surface, thereby reducing the likelihood of immune evasion.}, language = {en} } @article{SchwinnMokhtariThuseketal.2021, author = {Schwinn, Stefanie and Mokhtari, Zeinab and Thusek, Sina and Schneider, Theresa and Sir{\´e}n, Anna-Leena and Tiemeyer, Nicola and Caruana, Ignazio and Miele, Evelina and Schlegel, Paul G. and Beilhack, Andreas and W{\"o}lfl, Matthias}, title = {Cytotoxic effects and tolerability of gemcitabine and axitinib in a xenograft model for c-myc amplified medulloblastoma}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-93586-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261476}, year = {2021}, abstract = {Medulloblastoma is the most common high-grade brain tumor in childhood. Medulloblastomas with c-myc amplification, classified as group 3, are the most aggressive among the four disease subtypes resulting in a 5-year overall survival of just above 50\%. Despite current intensive therapy regimens, patients suffering from group 3 medulloblastoma urgently require new therapeutic options. Using a recently established c-myc amplified human medulloblastoma cell line, we performed an in-vitro-drug screen with single and combinatorial drugs that are either already clinically approved or agents in the advanced stage of clinical development. Candidate drugs were identified in vitro and then evaluated in vivo. Tumor growth was closely monitored by BLI. Vessel development was assessed by 3D light-sheet-fluorescence-microscopy. We identified the combination of gemcitabine and axitinib to be highly cytotoxic, requiring only low picomolar concentrations when used in combination. In the orthotopic model, gemcitabine and axitinib showed efficacy in terms of tumor control and survival. In both models, gemcitabine and axitinib were better tolerated than the standard regimen comprising of cisplatin and etoposide phosphate. 3D light-sheet-fluorescence-microscopy of intact tumors revealed thinning and rarefication of tumor vessels, providing one explanation for reduced tumor growth. Thus, the combination of the two drugs gemcitabine and axitinib has favorable effects on preventing tumor progression in an orthotopic group 3 medulloblastoma xenograft model while exhibiting a favorable toxicity profile. The combination merits further exploration as a new approach to treat high-risk group 3 medulloblastoma.}, language = {en} } @article{BaeuerleinQureischiMokhtarietal.2021, author = {B{\"a}uerlein, Carina A. and Qureischi, Musga and Mokhtari, Zeinab and Tabares, Paula and Brede, Christian and Jord{\´a}n Garrote, Ana-Laura and Riedel, Simone S. and Chopra, Martin and Reu, Simone and Mottok, Anja and Arellano-Viera, Estibaliz and Graf, Carolin and Kurzwart, Miriam and Schmiedgen, Katharina and Einsele, Hermann and W{\"o}lfl, Matthias and Schlegel, Paul-Gerhardt and Beilhack, Andreas}, title = {A T-Cell Surface Marker Panel Predicts Murine Acute Graft-Versus-Host Disease}, series = {Frontiers in Immunology}, volume = {11}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2020.593321}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224290}, year = {2021}, abstract = {Acute graft-versus-host disease (aGvHD) is a severe and often life-threatening complication of allogeneic hematopoietic cell transplantation (allo-HCT). AGvHD is mediated by alloreactive donor T-cells targeting predominantly the gastrointestinal tract, liver, and skin. Recent work in mice and patients undergoing allo-HCT showed that alloreactive T-cells can be identified by the expression of α4β7 integrin on T-cells even before manifestation of an aGvHD. Here, we investigated whether the detection of a combination of the expression of T-cell surface markers on peripheral blood (PB) CD8\(^+\) T-cells would improve the ability to predict aGvHD. To this end, we employed two independent preclinical models of minor histocompatibility antigen mismatched allo-HCT following myeloablative conditioning. Expression profiles of integrins, selectins, chemokine receptors, and activation markers of PB donor T-cells were measured with multiparameter flow cytometry at multiple time points before the onset of clinical aGvHD symptoms. In both allo-HCT models, we demonstrated a significant upregulation of α4β7 integrin, CD162E, CD162P, and conversely, a downregulation of CD62L on donor T-cells, which could be correlated with the development of aGvHD. Other surface markers, such as CD25, CD69, and CC-chemokine receptors were not found to be predictive markers. Based on these preclinical data from mouse models, we propose a surface marker panel on peripheral blood T-cells after allo-HCT combining α4β7 integrin with CD62L, CD162E, and CD162P (cutaneous lymphocyte antigens, CLA, in humans) to identify patients at risk for developing aGvHD early after allo-HCT.}, language = {en} }