@article{ChopraBiehlSteinfattetal.2016, author = {Chopra, Martin and Biehl, Marlene and Steinfatt, Tim and Brandl, Andreas and Kums, Juliane and Amich, Jorge and Vaeth, Martin and Kuen, Janina and Holtappels, Rafaela and Podlech, J{\"u}rgen and Mottok, Anja and Kraus, Sabrina and Jord{\´a}n-Garotte, Ana-Laura and B{\"a}uerlein, Carina A. and Brede, Christian and Ribechini, Eliana and Fick, Andrea and Seher, Axel and Polz, Johannes and Ottmueller, Katja J. and Baker, Jeannette and Nishikii, Hidekazu and Ritz, Miriam and Mattenheimer, Katharina and Schwinn, Stefanie and Winter, Thorsten and Sch{\"a}fer, Viktoria and Krappmann, Sven and Einsele, Hermann and M{\"u}ller, Thomas D. and Reddehase, Matthias J. and Lutz, Manfred B. and M{\"a}nnel, Daniela N. and Berberich-Siebelt, Friederike and Wajant, Harald and Beilhack, Andreas}, title = {Exogenous TNFR2 activation protects from acute GvHD via host T reg cell expansion}, series = {Journal of Experimental Medicine}, volume = {213}, journal = {Journal of Experimental Medicine}, number = {9}, doi = {10.1084/jem.20151563}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187640}, pages = {1881-1900}, year = {2016}, abstract = {Donor CD4\(^+\)Foxp3\(^+\) regulatory T cells (T reg cells) suppress graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (HCT allo-HCT]). Current clinical study protocols rely on the ex vivo expansion of donor T reg cells and their infusion in high numbers. In this study, we present a novel strategy for inhibiting GvHD that is based on the in vivo expansion of recipient T reg cells before allo-HCT, exploiting the crucial role of tumor necrosis factor receptor 2 (TNFR2) in T reg cell biology. Expanding radiation-resistant host T reg cells in recipient mice using a mouse TNFR2-selective agonist before allo-HCT significantly prolonged survival and reduced GvHD severity in a TNFR2-and T reg cell-dependent manner. The beneficial effects of transplanted T cells against leukemia cells and infectious pathogens remained unaffected. A corresponding human TNFR2-specific agonist expanded human T reg cells in vitro. These observations indicate the potential of our strategy to protect allo-HCT patients from acute GvHD by expanding T reg cells via selective TNFR2 activation in vivo.}, language = {en} } @article{MuellerQuandtMarienfeldetal.2013, author = {Mueller, Kerstin and Quandt, Jasmin and Marienfeld, Ralf B. and Weihrich, Petra and Fiedler, Katja and Claussnitzer, Melina and Laumen, Helmut and Vaeth, Martin and Berberich-Siebelt, Frederike and Serfling, Edgar and Wirth, Thomas and Brunner, Cornelia}, title = {Octamer-dependent transcription in T cells is mediated by NFAT and \(NF-\kappa B\)}, series = {Nucleic Acids Research}, volume = {41}, journal = {Nucleic Acids Research}, number = {4}, issn = {1362-4962}, doi = {10.1093/nar/gks1349}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123280}, pages = {2138-2154}, year = {2013}, abstract = {The transcriptional co-activator BOB.1/OBF.1 was originally identified in B cells and is constitutively expressed throughout B cell development. BOB.1/OBF.1 associates with the transcription factors Oct1 and Oct2, thereby enhancing octamer-dependent transcription. In contrast, in T cells, BOB.1/OBF.1 expression is inducible by treatment of cells with PMA/Ionomycin or by antigen receptor engagement, indicating a marked difference in the regulation of BOB.1/OBF.1 expression in B versus T cells. The molecular mechanisms underlying the differential expression of BOB.1/OBF.1 in T and B cells remain largely unknown. Therefore, the present study focuses on mechanisms controlling the transcriptional regulation of BOB.1/OBF.1 and Oct2 in T cells. We show that both calcineurin- and \(NF-\kappa B\)-inhibitors efficiently attenuate the expression of BOB.1/OBF.1 and Oct2 in T cells. In silico analyses of the BOB.1/OBF.1 promoter revealed the presence of previously unappreciated combined NFAT/\(NF-\kappa B\) sites. An array of genetic and biochemical analyses illustrates the involvement of the \(Ca^{2+}\)/calmodulin-dependent phosphatase calcineurin as well as NFAT and \(NF-\kappa B\) transcription factors in the transcriptional regulation of octamer-dependent transcription in T cells. Conclusively, impaired expression of BOB.1/OBF.1 and Oct2 and therefore a hampered octamer-dependent transcription may participate in T cell-mediated immunodeficiency caused by the deletion of NFAT or \(NF-\kappa B\) transcription factors.}, language = {en} } @article{DmochewitzFoertschZwergeretal.2013, author = {Dmochewitz, Lydia and F{\"o}rtsch, Christina and Zwerger, Christian and Vaeth, Martin and Felder, Edward and Huber-Lang, Markus and Barth, Holger}, title = {A Recombinant Fusion Toxin Based on Enzymatic Inactive C3bot1 Selectively Targets Macrophages}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0054517}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131189}, pages = {e54517}, year = {2013}, abstract = {Background: The C3bot1 protein (~23 kDa) from Clostridium botulinum ADP-ribosylates and thereby inactivates Rho. C3bot1 is selectively taken up into the cytosol of monocytes/macrophages but not of other cell types such as epithelial cells or fibroblasts. Most likely, the internalization occurs by a specific endocytotic pathway via acidified endosomes. Methodology/Principal Findings: Here, we tested whether enzymatic inactive C3bot1E174Q serves as a macrophage-selective transport system for delivery of enzymatic active proteins into the cytosol of such cells. Having confirmed that C3bot1E174Q does not induce macrophage activation, we used the actin ADP-ribosylating C2I (~50 kDa) from Clostridium botulinum as a reporter enzyme for C3bot1E174Q-mediated delivery into macrophages. The recombinant C3bot1E174Q-C2I fusion toxin was cloned and expressed as GST-protein in Escherichia coli. Purified C3bot1E174Q-C2I was recognized by antibodies against C2I and C3bot and showed C2I-specific enzyme activity in vitro. When applied to cultured cells C3bot1E174Q-C2I ADP-ribosylated actin in the cytosol of macrophages including J774A.1 and RAW264.7 cell lines as well as primary cultured human macrophages but not of epithelial cells. Together with confocal fluorescence microscopy experiments, the biochemical data indicate the selective uptake of a recombinant C3-fusion toxin into the cytosol of macrophages. Conclusions/Significance: In summary, we demonstrated that C3bot1E174Q can be used as a delivery system for fast, selective and specific transport of enzymes into the cytosol of living macrophages. Therefore, C3-based fusion toxins can represent valuable molecular tools in experimental macrophage pharmacology and cell biology as well as attractive candidates to develop new therapeutic approaches against macrophage-associated diseases.}, language = {en} } @misc{SerflingAvotsKleinHesslingetal.2012, author = {Serfling, Edgar and Avots, Andris and Klein-Hessling, Stefan and Rudolf, Ronald and Vaeth, Martin and Berberich-Siebelt, Friederike}, title = {NFATc1/alphaA: The other Face of NFAT Factors in Lymphocytes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75748}, year = {2012}, abstract = {In effector T and B cells immune receptor signals induce within minutes a rise of intracellular Ca++, the activation of the phosphatase calcineurin and the translocation of NFAT transcription factors from cytosol to nucleus. In addition to this first wave of NFAT activation, in a second step the occurrence of NFATc1/αA, a short isoform of NFATc1, is strongly induced. Upon primary stimulation of lymphocytes the induction of NFATc1/αA takes place during the G1 phase of cell cycle. Due to an auto-regulatory feedback circuit high levels of NFATc1/αA are kept constant during persistent immune receptor stimulation. Contrary to NFATc2 and further NFATc proteins which dampen lymphocyte proliferation, induce anergy and enhance activation induced cell death (AICD), NFATc1/αA supports antigenmediated proliferation and protects lymphocytes against rapid AICD. Whereas high concentrations of NFATc1/αA can also lead to apoptosis, in collaboration with NF-κB-inducing co-stimulatory signals they support the survival of mature lymphocytes in late phases after their activation. However, if dysregulated, NFATc1/αA appears to contribute to lymphoma genesis and - as we assume - to further disorders of the lymphoid system. While the molecular details of NFATc1/αA action and its contribution to lymphoid disorders have to be investigated, NFATc1/αA differs in its generation and function markedly from all the other NFAT proteins which are expressed in lymphoid cells. Therefore, it represents a prime target for causal therapies of immune disorders in future.}, subject = {Medizin}, language = {en} } @article{SaintFleurLominyMausVaethetal.2018, author = {Saint Fleur-Lominy, Shella and Maus, Mate and Vaeth, Martin and Lange, Ingo and Zee, Isabelle and Suh, David and Liu, Cynthia and Wu, Xiaojun and Tikhonova, Anastasia and Aifantis, Iannis and Feske, Stefan}, title = {STIM1 and STIM2 Mediate Cancer-Induced Inflammation in T Cell Acute Lymphoblastic Leukemia}, series = {Cell Reports}, volume = {24}, journal = {Cell Reports}, number = {11}, doi = {10.1016/j.celrep.2018.08.030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227259}, pages = {3045-3060}, year = {2018}, abstract = {T cell acute lymphoblastic leukemia (T-ALL) is commonly associated with activating mutations in the NOTCH1 pathway. Recent reports have shown a link between NOTCH1 signaling and intracellular Ca2+ homeostasis in T-ALL. Here, we investigate the role of store-operated Ca2+ entry (SOCE) mediated by the Ca2+ channel ORAI1 and its activators STIM1 and STIM2 in T-ALL. Deletion of STIM1 and STIM2 in leukemic cells abolishes SOCE and significantly prolongs the survival of mice in a NOTCH1-dependent model of T-ALL. The survival advantage is unrelated to the leukemic cell burden but is associated with the SOCE-dependent ability of malignant T lymphoblasts to cause inflammation in leukemia-infiltrated organs. Mice with STIM1/STIM2-deficient T-ALL show a markedly reduced necroinflammatory response in leukemia-infiltrated organs and downregulation of signaling pathways previously linked to cancer-induced inflammation. Our study shows that leukemic T lymphoblasts cause inflammation of leukemia-infiltrated organs that is dependent on SOCE.}, language = {en} } @article{KleinHesslingMuhammadKleinetal.2017, author = {Klein-Hessling, Stefan and Muhammad, Khalid and Klein, Matthias and Pusch, Tobias and Rudolf, Ronald and Fl{\"o}ter, Jessica and Qureischi, Musga and Beilhack, Andreas and Vaeth, Martin and Kummerow, Carsten and Backes, Christian and Schoppmeyer, Rouven and Hahn, Ulrike and Hoth, Markus and Bopp, Tobias and Berberich-Siebelt, Friederike and Patra, Amiya and Avots, Andris and M{\"u}ller, Nora and Schulze, Almut and Serfling, Edgar}, title = {NFATc1 controls the cytotoxicity of CD8\(^{+}\) T cells}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, number = {511}, doi = {10.1038/s41467-017-00612-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170353}, year = {2017}, abstract = {Cytotoxic T lymphocytes are effector CD8\(^{+}\) T cells that eradicate infected and malignant cells. Here we show that the transcription factor NFATc1 controls the cytotoxicity of mouse cytotoxic T lymphocytes. Activation of Nfatc1\(^{-/-}\) cytotoxic T lymphocytes showed a defective cytoskeleton organization and recruitment of cytosolic organelles to immunological synapses. These cells have reduced cytotoxicity against tumor cells, and mice with NFATc1-deficient T cells are defective in controlling Listeria infection. Transcriptome analysis shows diminished RNA levels of numerous genes in Nfatc1\(^{-/-}\) CD8\(^{+}\) T cells, including Tbx21, Gzmb and genes encoding cytokines and chemokines, and genes controlling glycolysis. Nfatc1\(^{-/-}\), but not Nfatc2\(^{-/-}\) CD8\(^{+}\) T cells have an impaired metabolic switch to glycolysis, which can be restored by IL-2. Genome-wide ChIP-seq shows that NFATc1 binds many genes that control cytotoxic T lymphocyte activity. Together these data indicate that NFATc1 is an important regulator of cytotoxic T lymphocyte effector functions.}, language = {en} } @article{JostKleinBrandetal.2023, author = {Jost, Priska and Klein, Franziska and Brand, Benjamin and Wahl, Vanessa and Wyatt, Amanda and Yildiz, Daniela and Boehm, Ulrich and Niemeyer, Barbara A. and Vaeth, Martin and Alansary, Dalia}, title = {Acute downregulation but not genetic ablation of murine MCU impairs suppressive capacity of regulatory CD4 T cells}, series = {International Journal of Molecular Sciences}, volume = {24}, journal = {International Journal of Molecular Sciences}, number = {9}, issn = {1422-0067}, doi = {10.3390/ijms24097772}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313621}, year = {2023}, abstract = {By virtue of mitochondrial control of energy production, reactive oxygen species (ROS) generation, and maintenance of Ca\(^{2+}\) homeostasis, mitochondria play an essential role in modulating T cell function. The mitochondrial Ca\(^{2+}\) uniporter (MCU) is the pore-forming unit in the main protein complex mediating mitochondrial Ca\(^{2+}\) uptake. Recently, MCU has been shown to modulate Ca\(^{2+}\) signals at subcellular organellar interfaces, thus fine-tuning NFAT translocation and T cell activation. The mechanisms underlying this modulation and whether MCU has additional T cell subpopulation-specific effects remain elusive. However, mice with germline or tissue-specific ablation of Mcu did not show impaired T cell responses in vitro or in vivo, indicating that 'chronic' loss of MCU can be functionally compensated in lymphocytes. The current work aimed to specifically investigate whether and how MCU influences the suppressive potential of regulatory CD4 T cells (Treg). We show that, in contrast to genetic ablation, acute siRNA-mediated downregulation of Mcu in murine Tregs results in a significant reduction both in mitochondrial Ca\(^{2+}\) uptake and in the suppressive capacity of Tregs, while the ratios of Treg subpopulations and the expression of hallmark transcription factors were not affected. These findings suggest that permanent genetic inactivation of MCU may result in compensatory adaptive mechanisms, masking the effects on the suppressive capacity of Tregs.}, language = {en} }