@article{LangenhorstTabaresGuldeetal.2018, author = {Langenhorst, Daniela and Tabares, Paula and Gulde, Tobias and Becklund, Bryan R. and Berr, Susanne and Surh, Charles D. and Beyersdorf, Niklas and H{\"u}nig, Thomas}, title = {Self-recognition sensitizes mouse and human regulatory T cells to low-dose CD28 superagonist stimulation}, series = {Frontiers in Immunology}, volume = {8}, journal = {Frontiers in Immunology}, number = {1985}, doi = {10.3389/fimmu.2017.01985}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159387}, year = {2018}, abstract = {In rodents, low doses of CD28-specific superagonistic monoclonal antibodies (CD28 superagonists, CD28SA) selectively activate regulatory T cells (Treg). This observation has recently been extended to humans, suggesting an option for the treatment of autoimmune and inflammatory diseases. However, a mechanistic explanation for this phenomenon is still lacking. Given that CD28SA amplify T cell receptor (TCR) signals, we tested the hypothesis that the weak tonic TCR signals received by conventional CD4\(^{+}\) T cells (Tconv) in the absence of cognate antigen require more CD28 signaling input for full activation than the stronger TCR signals received by self-reactive Treg. We report that in vitro, the response of mouse Treg and Tconv to CD28SA strongly depends on MHC class II expression by antigen-presenting cells. To separate the effect of tonic TCR signals from self-peptide recognition, we compared the response of wild-type Treg and Tconv to low and high CD28SA doses upon transfer into wild-type or H-2M knockout mice, which lack a self-peptide repertoire. We found that the superior response of Treg to low CD28SA doses was lost in the absence of self-peptide presentation. We also tested if potentially pathogenic autoreactive Tconv would benefit from self-recognition-induced sensitivity to CD28SA stimulation by transferring TCR transgenic OVA-specific Tconv into OVA-expressing mice and found that low-dose CD28SA application inhibited, rather than supported, their expansion, presumably due to the massive concomitant activation of Treg. Finally, we report that also in the in vitro response of human peripheral blood mononuclear cells to CD28SA, HLA II blockade interferes with the expansion of Treg by low-dose CD28SA stimulation. These results provide a rational basis for the further development of low-dose CD28SA therapy for the improvement of Treg activity.}, language = {en} } @article{KraftDrechslerSchuhmannetal.2015, author = {Kraft, Peter and Drechsler, Christiane and Schuhmann, Michael K. and Gunreben, Ignaz and Kleinschnitz, Christoph}, title = {Characterization of Peripheral Immune Cell Subsets in Patients with Acute and Chronic Cerebrovascular Disease: A Case-Control Study}, series = {International Journal of Molecular Science}, volume = {16}, journal = {International Journal of Molecular Science}, number = {10}, doi = {10.3390/ijms161025433}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126319}, pages = {25433-25449}, year = {2015}, abstract = {Immune cells (IC) play a crucial role in murine stroke pathophysiology. However, data are limited on the role of these cells in ischemic stroke in humans. We therefore aimed to characterize and compare peripheral IC subsets in patients with acute ischemic stroke/transient ischemic attack (AIS/TIA), chronic cerebrovascular disease (CCD) and healthy volunteers (HV). We conducted a case-control study of patients with AIS/TIA (n = 116) or CCD (n = 117), and HV (n = 104) who were enrolled at the University Hospital W{\"u}rzburg from 2010 to 2013. We determined the expression and quantity of IC subsets in the three study groups and performed correlation analyses with demographic and clinical parameters. The quantity of several IC subsets differed between the AIS/TIA, CCD, and HV groups. Several clinical and demographic variables independently predicted the quantity of IC subsets in patients with AIS/TIA. No significant changes in the quantity of IC subsets occurred within the first three days after AIS/TIA. Overall, these findings strengthen the evidence for a pathophysiologic role of IC in human ischemic stroke and the potential use of IC-based biomarkers for the prediction of stroke risk. A comprehensive description of IC kinetics is crucial to enable the design of targeted treatment strategies.}, 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} } @article{HeuserGototPiotrowskietal.2017, author = {Heuser, Christoph and Gotot, Janine and Piotrowski, Eveline Christina and Philipp, Marie-Sophie and Courr{\`e}ges, Christina Johanna Felicia and Otte, Martin Sylvester and Guo, Linlin and Schmid-Burgk, Jonathan Leo and Hornung, Veit and Heine, Annkristin and Knolle, Percy Alexander and Garbi, Natalio and Serfling, Edgar and Evaristo, C{\´e}sar and Thaiss, Friedrich and Kurts, Christian}, title = {Prolonged IKK\(\beta\) Inhibition Improves Ongoing CTL Antitumor Responses by Incapacitating Regulatory T Cells}, series = {Cell Reports}, volume = {21}, journal = {Cell Reports}, number = {3}, doi = {10.1016/j.celrep.2017.09.082}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173643}, pages = {578-586}, year = {2017}, abstract = {Regulatory T cells (Tregs) prevent autoimmunity but limit antitumor immunity. The canonical NF-\(\kappa\)B signaling pathway both activates immunity and promotes thymic Treg development. Here, we report that mature Tregs continue to require NF-\(\kappa\)B signaling through I\(\kappa\)B-kinase \(\beta\) (IKK\(\beta\)) after thymic egress. Mice lacking IKK\(\beta\) in mature Tregs developed scurfy-like immunopathology due to death of peripheral FoxP3\(^+\) Tregs. Also, pharmacological IKK\(\beta\) inhibition reduced Treg numbers in the circulation by ~50\% and downregulated FoxP3 and CD25 expression and STAT5 phosphorylation. In contrast, activated cytotoxic T lymphocytes (CTLs) were resistant to IKK\(\beta\) inhibition because other pathways, in particular nuclear factor of activated T cells (NFATc1) signaling, sustained their survival and expansion. In a melanoma mouse model, IKK\(\beta\) inhibition after CTL cross-priming improved the antitumor response and delayed tumor growth. In conclusion, prolonged IKK\(\beta\) inhibition decimates circulating Tregs and improves CTL responses when commenced after tumor vaccination, indicating that IKK\(\beta\) represents a druggable checkpoint.}, language = {en} } @article{DoehlerSchneiderEckertetal.2017, author = {D{\"o}hler, Anja and Schneider, Theresa and Eckert, Ina and Ribechini, Eliana and Andreas, Nico and Riemann, Marc and Reizis, Boris and Weih, Falk and Lutz, Manfred B.}, title = {RelB\(^{+}\) Steady-State Migratory Dendritic Cells Control the Peripheral Pool of the Natural Foxp3\(^{+}\) Regulatory T Cells}, series = {Frontiers in Immunology}, volume = {8}, journal = {Frontiers in Immunology}, number = {726}, doi = {10.3389/fimmu.2017.00726}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158121}, year = {2017}, abstract = {Thymus-derived natural Foxp3\(^{+}\) CD4\(^{+}\) regulatory T cells (nTregs) play a key role in maintaining immune tolerance and preventing autoimmune disease. Several studies indicate that dendritic cells (DCs) are critically involved in the maintenance and proliferation of nTregs. However, the mechanisms how DCs manage to keep the peripheral pool at constant levels remain poorly understood. Here, we describe that the NF-κB/Rel family transcription factor RelB controls the frequencies of steady-state migratory DCs (ssmDCs) in peripheral lymph nodes and their numbers control peripheral nTreg homeostasis. DC-specific RelB depletion was investigated in CD11c-Cre × RelB\(^{fl/fl}\) mice (RelB\(^{DCko}\)), which showed normal frequencies of resident DCs in lymph nodes and spleen while the subsets of CD103\(^{-}\) Langerin\(^{-}\) dermal DCs (dDCs) and Langerhans cells but not CD103\(^{+}\) Langerin\(^{+}\) dDC of the ssmDCs in skin-draining lymph nodes were increased. Enhanced frequencies and proliferation rates were also observed for nTregs and a small population of CD4\(^{+}\) CD44\(^{high}\) CD25\(^{low}\) memory-like T cells (Tml). Interestingly, only the Tml but not DCs showed an increase in IL-2-producing capacity in lymph nodes of RelB\(^{DCko}\) mice. Blocking of IL-2 in vivo reduced the frequency of nTregs but increased the Tml frequencies, followed by a recovery of nTregs. Taken together, by employing RelB\(^{DCko}\) mice with increased frequencies of ssmDCs our data indicate a critical role for specific ssmDC subsets for the peripheral nTreg and IL-2\(^{+}\) Tml frequencies during homeostasis.}, language = {en} } @article{CochainChaudhariKochetal.2014, author = {Cochain, Clement and Chaudhari, Sweena M. and Koch, Miriam and Wiendl, Heinz and Eckstein, Hans-Henning and Zernecke, Alma}, title = {Programmed Cell Death-1 Deficiency Exacerbates T Cell Activation and Atherogenesis despite Expansion of Regulatory T Cells in Atherosclerosis-Prone Mice}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {4}, issn = {1932-6203}, doi = {10.1371/journal.pone.0093280}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119823}, pages = {e93280}, year = {2014}, abstract = {T cell activation represents a double-edged sword in atherogenesis, as it promotes both pro-inflammatory T cell activation and atheroprotective Foxp3(+) regulatory T cell (Treg) responses. Here, we investigated the role of the co-inhibitory receptor programmed cell death-1 (PD-1) in T cell activation and CD4(+) T cell polarization towards pro-atherogenic or atheroprotective responses in mice. Mice deficient for both low density lipoprotein receptor and PD-1 (Ldlr(-/-)Pd1(-/-)) displayed striking increases in systemic CD4(+) and CD8(+) T cell activation after 9 weeks of high fat diet feeding, associated with an expansion of both pro-atherogenic IFNγ-secreting T helper 1 cells and atheroprotective Foxp3+ Tregs. Importantly, PD-1 deficiency did not affect Treg suppressive function in vitro. Notably, PD-1 deficiency exacerbated atherosclerotic lesion growth and entailed a massive infiltration of T cells in atherosclerotic lesions. In addition, aggravated hypercholesterolemia was observed in Ldlr(-/-)Pd1(-/-) mice. In conclusion, we here demonstrate that although disruption of PD-1 signaling enhances both pro- and anti-atherogenic T cell responses in Ldlr(-/-) mice, pro-inflammatory T cell activation prevails and enhances dyslipidemia, vascular inflammation and atherosclerosis.}, language = {en} } @article{ChopraLangSalzmannetal.2013, author = {Chopra, Martin and Lang, Isabell and Salzmann, Steffen and Pachel, Christina and Kraus, Sabrina and B{\"a}uerlein, Carina A. and Brede, Christian and Jord{\´a}n Garrote, Ana-Laura and Mattenheimer, Katharina and Ritz, Miriam and Schwinn, Stefanie and Graf, Carolin and Sch{\"a}fer, Viktoria and Frantz, Stefan and Einsele, Hermann and Wajant, Harald and Beilhack, Andreas}, title = {Tumor Necrosis Factor Induces Tumor Promoting and Anti-Tumoral Effects on Pancreatic Cancer via TNFR1}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075737}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97246}, year = {2013}, abstract = {Multiple activities are ascribed to the cytokine tumor necrosis factor (TNF) in health and disease. In particular, TNF was shown to affect carcinogenesis in multiple ways. This cytokine acts via the activation of two cell surface receptors, TNFR1, which is associated with inflammation, and TNFR2, which was shown to cause anti-inflammatory signaling. We assessed the effects of TNF and its two receptors on the progression of pancreatic cancer by in vivo bioluminescence imaging in a syngeneic orthotopic tumor mouse model with Panc02 cells. Mice deficient for TNFR1 were unable to spontaneously reject Panc02 tumors and furthermore displayed enhanced tumor progression. In contrast, a fraction of wild type (37.5\%), TNF deficient (12.5\%), and TNFR2 deficient mice (22.2\%) were able to fully reject the tumor within two weeks. Pancreatic tumors in TNFR1 deficient mice displayed increased vascular density, enhanced infiltration of CD4+ T cells and CD4+ forkhead box P3 (FoxP3)+ regulatory T cells (Treg) but reduced numbers of CD8+ T cells. These alterations were further accompanied by transcriptional upregulation of IL4. Thus, TNF and TNFR1 are required in pancreatic ductal carcinoma to ensure optimal CD8+ T cell-mediated immunosurveillance and tumor rejection. Exogenous systemic administration of human TNF, however, which only interacts with murine TNFR1, accelerated tumor progression. This suggests that TNFR1 has basically the capability in the Panc02 model to trigger pro-and anti-tumoral effects but the spatiotemporal availability of TNF seems to determine finally the overall outcome.}, language = {en} } @article{BadrMcFlederWuetal.2022, author = {Badr, Mohammad and McFleder, Rhonda L. and Wu, Jingjing and Knorr, Susanne and Koprich, James B. and H{\"u}nig, Thomas and Brotchie, Jonathan M. and Volkmann, Jens and Lutz, Manfred B. and Ip, Chi Wang}, title = {Expansion of regulatory T cells by CD28 superagonistic antibodies attenuates neurodegeneration in A53T-α-synuclein Parkinson's disease mice}, series = {Journal of Neuroinflammation}, volume = {19}, journal = {Journal of Neuroinflammation}, doi = {10.1186/s12974-022-02685-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300580}, year = {2022}, abstract = {Background Regulatory CD4\(^+\)CD25\(^+\)FoxP3\(^+\) T cells (Treg) are a subgroup of T lymphocytes involved in maintaining immune balance. Disturbance of Treg number and impaired suppressive function of Treg correlate with Parkinson's disease severity. Superagonistic anti-CD28 monoclonal antibodies (CD28SA) activate Treg and cause their expansion to create an anti-inflammatory environment. Methods Using the AAV1/2-A53T-α-synuclein Parkinson's disease mouse model that overexpresses the pathogenic human A53T-α-synuclein (hαSyn) variant in dopaminergic neurons of the substantia nigra, we assessed the neuroprotective and disease-modifying efficacy of a single intraperitoneal dose of CD28SA given at an early disease stage. Results CD28SA led to Treg expansion 3 days after delivery in hαSyn Parkinson's disease mice. At this timepoint, an early pro-inflammation was observed in vehicle-treated hαSyn Parkinson's disease mice with elevated percentages of CD8\(^+\)CD69\(^+\) T cells in brain and increased levels of interleukin-2 (IL-2) in the cervical lymph nodes and spleen. These immune responses were suppressed in CD28SA-treated hαSyn Parkinson's disease mice. Early treatment with CD28SA attenuated dopaminergic neurodegeneration in the SN of hαSyn Parkinson's disease mice accompanied with reduced brain numbers of activated CD4\(^+\), CD8\(^+\) T cells and CD11b\(^+\) microglia observed at the late disease-stage 10 weeks after AAV injection. In contrast, a later treatment 4 weeks after AAV delivery failed to reduce dopaminergic neurodegeneration. Conclusions Our data indicate that immune modulation by Treg expansion at a timepoint of overt inflammation is effective for treatment of hαSyn Parkinson's disease mice and suggest that the concept of early immune therapy could pose a disease-modifying option for Parkinson's disease patients.}, language = {en} }