TY - JOUR A1 - Schmid, Tobias A1 - Falter, Lena A1 - Weber, Sabine A1 - Müller, Nils A1 - Molitor, Konstantin A1 - Zeller, David A1 - Weber-Steffens, Dorothea A1 - Hehlgans, Thomas A1 - Wajant, Harald A1 - Mostböck, Sven A1 - Männel, Daniela N. T1 - Chronic inflammation increases the sensitivity of mouse Treg for TNFR2 costimulation JF - Frontiers in Immunology N2 - TNF receptor type 2 (TNFR2) has gained attention as a costimulatory receptor for T cells and as critical factor for the development of regulatory T cells (Treg) and myeloid suppressor cells. Using the TNFR2-specific agonist TNCscTNF80, direct effects of TNFR2 activation on myeloid cells and T cells were investigated in mice. \(In\) \(vitro\), TNCscTNF80 induced T cell proliferation in a costimulatory fashion, and also supported \(in\) \(vitro\) expansion of Treg cells. In addition, activation of TNFR2 retarded differentiation of bone marrow-derived immature myeloid cells in culture and reduced their suppressor function. \(In\) \(vivo\) application of TNCscTNF80-induced mild myelopoiesis in naïve mice without affecting the immune cell composition. Already a single application expanded Treg cells and improved suppression of CD4 T cells in mice with chronic inflammation. By contrast, multiple applications of the TNFR2 agonist were required to expand Treg cells in naïve mice. Improved suppression of T cell proliferation depended on expression of TNFR2 by T cells in mice repeatedly treated with TNCscTNF80, without a major contribution of TNFR2 on myeloid cells. Thus, TNFR2 activation on T cells in naïve mice can lead to immune suppression \(in\) \(vivo\). These findings support the important role of TNFR2 for Treg cells in immune regulation. KW - molecular medicine KW - inflammation KW - immune regulation KW - costimulation KW - MDSC KW - TNFR2 KW - regulatory T cell Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173259 VL - 8 ER - TY - JOUR A1 - Schanbacher, Constanze A1 - Hermanns, Heike M. A1 - Lorenz, Kristina A1 - Wajant, Harald A1 - Lang, Isabell T1 - Complement 1q/tumor necrosis factor-related proteins (CTRPs): structure, receptors and signaling JF - Biomedicines N2 - Adiponectin and the other 15 members of the complement 1q (C1q)/tumor necrosis factor (TNF)-related protein (CTRP) family are secreted proteins composed of an N-terminal variable domain followed by a stalk region and a characteristic C-terminal trimerizing globular C1q (gC1q) domain originally identified in the subunits of the complement protein C1q. We performed a basic PubMed literature search for articles mentioning the various CTRPs or their receptors in the abstract or title. In this narrative review, we briefly summarize the biology of CTRPs and focus then on the structure, receptors and major signaling pathways of CTRPs. Analyses of CTRP knockout mice and CTRP transgenic mice gave overwhelming evidence for the relevance of the anti-inflammatory and insulin-sensitizing effects of CTRPs in autoimmune diseases, obesity, atherosclerosis and cardiac dysfunction. CTRPs form homo- and heterotypic trimers and oligomers which can have different activities. The receptors of some CTRPs are unknown and some receptors are redundantly targeted by several CTRPs. The way in which CTRPs activate their receptors to trigger downstream signaling pathways is largely unknown. CTRPs and their receptors are considered as promising therapeutic targets but their translational usage is still hampered by the limited knowledge of CTRP redundancy and CTRP signal transduction. KW - adiponectin KW - AMPK KW - C1q/TNF related protein (CTRP) KW - inflammation KW - metabolism Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304136 SN - 2227-9059 VL - 11 IS - 2 ER - TY - JOUR A1 - Pachel, Christina A1 - Mathes, Denise A1 - Bayer, Barbara A1 - Dienesch, Charlotte A1 - Wangorsch, Gaby A1 - Heitzmann, Wolfram A1 - Lang, Isabell A1 - Ardehali, Hossein A1 - Ertl, Georg A1 - Dandekar, Thomas A1 - Wajant, Harald A1 - Frantz, Stefan T1 - Exogenous Administration of a Recombinant Variant of TWEAK Impairs Healing after Myocardial Infarction by Aggravation of Inflammation JF - PLoS ONE N2 - Background: Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factorinducible 14 (Fn14) are upregulated after myocardial infarction (MI) in both humans and mice. They modulate inflammation and the extracellular matrix, and could therefore be important for healing and remodeling after MI. However, the function of TWEAK after MI remains poorly defined. Methods and results: Following ligation of the left coronary artery, mice were injected twice per week with a recombinant human serum albumin conjugated variant of TWEAK (HSA-Flag-TWEAK), mimicking the activity of soluble TWEAK. Treatment with HSA-Flag-TWEAK resulted in significantly increased mortality in comparison to the placebo group due to myocardial rupture. Infarct size, extracellular matrix remodeling, and apoptosis rates were not different after MI. However, HSA-Flag-TWEAK treatment increased infiltration of proinflammatory cells into the myocardium. Accordingly, depletion of neutrophils prevented cardiac ruptures without modulating all-cause mortality. Conclusion: Treatment of mice with HSA-Flag-TWEAK induces myocardial healing defects after experimental MI. This is mediated by an exaggerated neutrophil infiltration into the myocardium. KW - apoptosis KW - myocardial infarction KW - neutrophils KW - cytokines KW - inflammation KW - myocardium KW - heart KW - extracellular matrix Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129889 VL - 8 IS - 11 ER - TY - JOUR A1 - Knop, Janin A1 - Spilgies, Lisanne M. A1 - Rufli, Stefanie A1 - Reinhart, Ramona A1 - Vasilikos, Lazaros A1 - Yabal, Monica A1 - Owsley, Erika A1 - Jost, Philipp J. A1 - Marsh, Rebecca A. A1 - Wajant, Harald A1 - Robinson, Mark D. A1 - Kaufmann, Thomas A1 - W. Wei-Lynn, Wong T1 - TNFR2 induced priming of the inflammasome leads to a RIPK1-dependent cell death in the absence of XIAP JF - Cell Death & Disease N2 - The pediatric immune deficiency X-linked proliferative disease-2 (XLP-2) is a unique disease, with patients presenting with either hemophagocytic lymphohistiocytosis (HLH) or intestinal bowel disease (IBD). Interestingly, XLP-2 patients display high levels of IL-18 in the serum even while in stable condition, presumably through spontaneous inflammasome activation. Recent data suggests that LPS stimulation can trigger inflammasome activation through a TNFR2/TNF/TNFR1 mediated loop in xiap−/− macrophages. Yet, the direct role TNFR2-specific activation plays in the absence of XIAP is unknown. We found TNFR2-specific activation leads to cell death in xiap−/− myeloid cells, particularly in the absence of the RING domain. RIPK1 kinase activity downstream of TNFR2 resulted in a TNF/TNFR1 cell death, independent of necroptosis. TNFR2-specific activation leads to a similar inflammatory NF-kB driven transcriptional profile as TNFR1 activation with the exception of upregulation of NLRP3 and caspase-11. Activation and upregulation of the canonical inflammasome upon loss of XIAP was mediated by RIPK1 kinase activity and ROS production. While both the inhibition of RIPK1 kinase activity and ROS production reduced cell death, as well as release of IL-1β, the release of IL-18 was not reduced to basal levels. This study supports targeting TNFR2 specifically to reduce IL-18 release in XLP-2 patients and to reduce priming of the inflammasome components. KW - cell death and immune response KW - inflammation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-325946 VL - 10 ER -