TY - JOUR A1 - Hohnmann, Christopher A1 - Milles, Bianca A1 - Schinke, Michael A1 - Schroeter, Michael A1 - Ulzheimer, Jochen A1 - Kraft, Peter A1 - Kleinschnitz, Christoph A1 - Lehmann, Paul V. A1 - Kuerten, Stefanie T1 - Categorization of multiple sclerosis relapse subtypes by B cell profiling in the blood JF - Acta Neuropathologica Communications N2 - Introduction B cells are attracting increasing attention in the pathogenesis of multiple sclerosis (MS). B cell-targeted therapies with monoclonal antibodies or plasmapheresis have been shown to be successful in a subset of patients. Here, patients with either relapsing-remitting (n = 24) or secondary progressive (n = 6) MS presenting with an acute clinical relapse were screened for their B cell reactivity to brain antigens and were re-tested three to nine months later. Enzyme-linked immunospot technique (ELISPOT) was used to identify brain-reactive B cells in peripheral blood mononuclear cells (PBMC) directly ex vivo and after 96 h of polyclonal stimulation. Clinical severity of symptoms was determined using the Expanded Disability Status Scale (EDSS). Results Nine patients displayed B cells in the blood producing brain-specific antibodies directly ex vivo. Six patients were classified as B cell positive donors only after polyclonal B cell stimulation. In 15 patients a B cell response to brain antigens was absent. Based on the autoreactive B cell response we categorized MS relapses into three different patterns. Patients who displayed brain-reactive B cell responses both directly ex vivo and after polyclonal stimulation (pattern I) were significantly younger than patients in whom only memory B cell responses were detectable or entirely absent (patterns II and III; p = 0.003). In one patient a conversion to a positive B cell response as measured directly ex vivo and subsequently also after polyclonal stimulation was associated with the development of a clinical relapse. The evaluation of the predictive value of a brain antigen-specific B cell response showed that seven of eight patients (87.5%) with a pattern I response encountered a clinical relapse during the observation period of 10 months, compared to two of five patients (40%) with a pattern II and three of 14 patients (21.4%) with a pattern III response (p = 0.0005; hazard ratio 6.08 (95% confidence interval 1.87-19.77). Conclusions Our data indicate actively ongoing B cell-mediated immunity against brain antigens in a subset of MS patients that may be causative of clinical relapses and provide new diagnostic and therapeutic options for a subset of patients. KW - predictive value KW - MS KW - ELISPOT KW - B cells KW - relapse Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126124 VL - 2 IS - 138 ER - TY - JOUR A1 - Hohmann, Christopher A1 - Milles, Bianca A1 - Schinke, Michael A1 - Schroeter, Michael A1 - Ulzheimer, Jochen A1 - Kraft, Peter A1 - Kleinschnitz, Christoph A1 - Lehmann, Paul V. A1 - Kuerten, Stefanie T1 - Categorization of multiple sclerosis relapse subtypes by B cell profiling in the blood JF - Acta Neuropathologica Communications N2 - INTRODUCTION: B cells are attracting increasing attention in the pathogenesis of multiple sclerosis (MS). B cell-targeted therapies with monoclonal antibodies or plasmapheresis have been shown to be successful in a subset of patients. Here, patients with either relapsing-remitting (n = 24) or secondary progressive (n = 6) MS presenting with an acute clinical relapse were screened for their B cell reactivity to brain antigens and were re-tested three to nine months later. Enzyme-linked immunospot technique (ELISPOT) was used to identify brain-reactive B cells in peripheral blood mononuclear cells (PBMC) directly ex vivo and after 96 h of polyclonal stimulation. Clinical severity of symptoms was determined using the Expanded Disability Status Scale (EDSS). RESULTS: Nine patients displayed B cells in the blood producing brain-specific antibodies directly ex vivo. Six patients were classified as B cell positive donors only after polyclonal B cell stimulation. In 15 patients a B cell response to brain antigens was absent. Based on the autoreactive B cell response we categorized MS relapses into three different patterns. Patients who displayed brain-reactive B cell responses both directly ex vivo and after polyclonal stimulation (pattern I) were significantly younger than patients in whom only memory B cell responses were detectable or entirely absent (patterns II and III; p = 0.003). In one patient a conversion to a positive B cell response as measured directly ex vivo and subsequently also after polyclonal stimulation was associated with the development of a clinical relapse. The evaluation of the predictive value of a brain antigen-specific B cell response showed that seven of eight patients (87.5%) with a pattern I response encountered a clinical relapse during the observation period of 10 months, compared to two of five patients (40%) with a pattern II and three of 14 patients (21.4%) with a pattern III response (p = 0.0005; hazard ratio 6.08 (95% confidence interval 1.87-19.77). CONCLUSIONS: Our data indicate actively ongoing B cell-mediated immunity against brain antigens in a subset of MS patients that may be causative of clinical relapses and provide new diagnostic and therapeutic options for a subset of patients. KW - ELISPOT KW - MS KW - predictive value KW - relapse KW - B cells Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120580 SN - 2051-5960 VL - 2 IS - 138 ER - TY - JOUR A1 - Kraft, Peter A1 - Drechsler, Christiane A1 - Gunreben, Ignaz A1 - Heuschmann, Peter Ulrich A1 - Kleinschnitz, Christoph T1 - Case-control study of platelet glycoprotein receptor Ib and IIb/IIIa expression in patients with acute and chronic cerebrovascular disease JF - PLoS ONE N2 - Background Animal models have been instrumental in defining thrombus formation, including the role of platelet surface glycoprotein (GP) receptors, in acute ischemic stroke (AIS). However, the involvement of GP receptors in human ischemic stroke pathophysiology and their utility as biomarkers for ischemic stroke risk and severity requires elucidation. Aims To determine whether platelet GPIb and GPIIb/IIIa receptors are differentially expressed in patients with AIS and chronic cerebrovascular disease (CCD) compared with healthy volunteers (HV) and to identify predictors of GPIb and GPIIb/IIIa expression. Methods This was a case-control study of 116 patients with AIS or transient ischemic attack (TIA), 117 patients with CCD, and 104 HV who were enrolled at our University hospital from 2010 to 2013. Blood sampling was performed once in the CCD and HV groups, and at several time points in patients with AIS or TIA. Linear regression and analysis of variance were used to analyze correlations between platelet GPIb and GPIIb/IIIa receptor numbers and demographic and clinical parameters. Results GPIb and GPIIb/IIIa receptor numbers did not significantly differ between the AIS, CCD, and HV groups. GPIb receptor expression level correlated significantly with the magnitude of GPIIb/IIIa receptor expression and the neutrophil count. In contrast, GPIIb/IIIa receptor numbers were not associated with peripheral immune-cell sub-population counts. Creactive protein was an independent predictor of GPIIb/IIIa (not GPIb) receptor numbers. Conclusions Platelet GPIb and GPIIb/IIIa receptor numbers did not distinguish between patient or control groups in this study, negating their potential use as a biomarker for predicting stroke risk. KW - von Willebrand factor KW - cardiovascular disease KW - increased risk KW - mice impact KW - polymorphisms inflammation KW - blood coagulability KW - atherosclerosis KW - acute ischemic stroke Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148806 VL - 10 IS - 3 ER - TY - JOUR A1 - Montellano, Felipe A. A1 - Kluter, Elisabeth J. A1 - Rücker, Viktoria A1 - Ungethüm, Kathrin A1 - Mackenrodt, Daniel A1 - Wiedmann, Silke A1 - Dege, Tassilo A1 - Quilitzsch, Anika A1 - Morbach, Caroline A1 - Frantz, Stefan A1 - Störk, Stefan A1 - Haeusler, Karl Georg A1 - Kleinschnitz, Christoph A1 - Heuschmann, Peter U. T1 - Cardiac dysfunction and high-sensitive C-reactive protein are associated with troponin T elevation in ischemic stroke: insights from the SICFAIL study JF - BMC Neurology N2 - Background Troponin elevation is common in ischemic stroke (IS) patients. The pathomechanisms involved are incompletely understood and comprise coronary and non-coronary causes, e.g. autonomic dysfunction. We investigated determinants of troponin elevation in acute IS patients including markers of autonomic dysfunction, assessed by heart rate variability (HRV) time domain variables. Methods Data were collected within the Stroke Induced Cardiac FAILure (SICFAIL) cohort study. IS patients admitted to the Department of Neurology, Würzburg University Hospital, underwent baseline investigation including cardiac history, physical examination, echocardiography, and blood sampling. Four HRV time domain variables were calculated in patients undergoing electrocardiographic Holter monitoring. Multivariable logistic regression with corresponding odds ratios (OR) and 95% confidence intervals (CI) was used to investigate the determinants of high-sensitive troponin T (hs-TnT) levels ≥14 ng/L. Results We report results from 543 IS patients recruited between 01/2014–02/2017. Of those, 203 (37%) had hs-TnT ≥14 ng/L, which was independently associated with older age (OR per year 1.05; 95% CI 1.02–1.08), male sex (OR 2.65; 95% CI 1.54–4.58), decreasing estimated glomerular filtration rate (OR per 10 mL/min/1.73 m2 0.71; 95% CI 0.61–0.84), systolic dysfunction (OR 2.79; 95% CI 1.22–6.37), diastolic dysfunction (OR 2.29; 95% CI 1.29–4.02), atrial fibrillation (OR 2.30; 95% CI 1.25–4.23), and increasing levels of C-reactive protein (OR 1.48 per log unit; 95% CI 1.22–1.79). We did not identify an independent association of troponin elevation with the investigated HRV variables. Conclusion Cardiac dysfunction and elevated C-reactive protein, but not a reduced HRV as surrogate of autonomic dysfunction, were associated with increased hs-TnT levels in IS patients independent of established cardiovascular risk factors. KW - echocardiography KW - ischemic stroke KW - troponin KW - heart failure KW - biomarkers Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300119 VL - 22 IS - 1 ER - TY - JOUR A1 - Albert-Weissenberger, Christiane A1 - Mencl, Stine A1 - Schuhmann, Michael K. A1 - Salur, Irmak A1 - Göb, Eva A1 - Langhauser, Friederike A1 - Hopp, Sarah A1 - Hennig, Nelli A1 - Meuth, Sven G. A1 - Nolte, Marc W. A1 - Sirén, Anna-Leena A1 - Kleinschnitz, Christoph T1 - C1-Inhibitor protects from focal brain trauma in a cortical cryolesion mice model by reducing thrombo-inflammation JF - Frontiers in Cellular Neuroscience N2 - Traumatic brain injury (TBI) induces a strong inflammatory response which includes blood-brain barrier damage, edema formation and infiltration of different immune cell subsets. More recently, microvascular thrombosis has been identified as another pathophysiological feature of TBI. The contact-kinin system represents an interface between inflammatory and thrombotic circuits and is activated in different neurological diseases. C1-Inhibitor counteracts activation of the contact-kinin system at multiple levels. We investigated the therapeutic potential of C1-Inhibitor in a model of TBI. Male and female C57BL/6 mice were subjected to cortical cryolesion and treated with C1-Inhibitor after 1 h. Lesion volumes were assessed between day 1 and day 5 and blood-brain barrier damage, thrombus formation as well as the local inflammatory response were determined post TBI. Treatment of male mice with 15.0 IU C1-Inhibitor, but not 7.5 IU, 1 h after cryolesion reduced lesion volumes by ~75% on day 1. This protective effect was preserved in female mice and at later stages of trauma. Mechanistically, C1-Inhibitor stabilized the blood-brain barrier and decreased the invasion of immune cells into the brain parenchyma. Moreover, C1-Inhibitor had strong antithrombotic effects. C1-Inhibitor represents a multifaceted anti-inflammatory and antithrombotic compound that prevents traumatic neurodegeneration in clinically meaningful settings. KW - thrombosis KW - traumatic brain injury KW - C1-inhibitor KW - blood-brain barrier KW - contact-kinin system KW - edema KW - inflammation Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119263 SN - 1662-5102 VL - 8 ER - TY - JOUR A1 - Koeniger, Tobias A1 - Bell, Luisa A1 - Mifka, Anika A1 - Enders, Michael A1 - Hautmann, Valentin A1 - Mekala, Subba Rao A1 - Kirchner, Philipp A1 - Ekici, Arif B. A1 - Schulz, Christian A1 - Wörsdörfer, Philipp A1 - Mencl, Stine A1 - Kleinschnitz, Christoph A1 - Ergün, Süleyman A1 - Kuerten, Stefanie T1 - Bone marrow‐derived myeloid progenitors in the leptomeninges of adult mice JF - Stem Cells N2 - Although the bone marrow contains most hematopoietic activity during adulthood, hematopoietic stem and progenitor cells can be recovered from various extramedullary sites. Cells with hematopoietic progenitor properties have even been reported in the adult brain under steady‐state conditions, but their nature and localization remain insufficiently defined. Here, we describe a heterogeneous population of myeloid progenitors in the leptomeninges of adult C57BL/6 mice. This cell pool included common myeloid, granulocyte/macrophage, and megakaryocyte/erythrocyte progenitors. Accordingly, it gave rise to all major myelo‐erythroid lineages in clonogenic culture assays. Brain‐associated progenitors persisted after tissue perfusion and were partially inaccessible to intravenous antibodies, suggesting their localization behind continuous blood vessel endothelium such as the blood‐arachnoid barrier. Flt3\(^{Cre}\) lineage tracing and bone marrow transplantation showed that the precursors were derived from adult hematopoietic stem cells and were most likely continuously replaced via cell trafficking. Importantly, their occurrence was tied to the immunologic state of the central nervous system (CNS) and was diminished in the context of neuroinflammation and ischemic stroke. Our findings confirm the presence of myeloid progenitors at the meningeal border of the brain and lay the foundation to unravel their possible functions in CNS surveillance and local immune cell production. KW - hematopoietic KW - meninges KW - mouse KW - myeloid KW - progenitor Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224452 VL - 39 IS - 2 SP - 227 EP - 239 ER - TY - JOUR A1 - Göbel, Kerstin A1 - Pankratz, Susann A1 - Asaridou, Chloi-Magdalini A1 - Herrmann, Alexander M. A1 - Bittner, Stefan A1 - Merker, Monika A1 - Ruck, Tobias A1 - Glumm, Sarah A1 - Langhauser, Friederike A1 - Kraft, Peter A1 - Krug, Thorsten F. A1 - Breuer, Johanna A1 - Herold, Martin A1 - Gross, Catharina C. A1 - Beckmann, Denise A1 - Korb-Pap, Adelheid A1 - Schuhmann, Michael K. A1 - Kuerten, Stefanie A1 - Mitroulis, Ioannis A1 - Ruppert, Clemens A1 - Nolte, Marc W. A1 - Panousis, Con A1 - Klotz, Luisa A1 - Kehrel, Beate A1 - Korn, Thomas A1 - Langer, Harald F. A1 - Pap, Thomas A1 - Nieswandt, Bernhard A1 - Wiendl, Heinz A1 - Chavakis, Triantafyllos A1 - Kleinschnitz, Christoph A1 - Meuth, Sven G. T1 - Blood coagulation factor XII drives adaptive immunity during neuroinflammation via CD87-mediated modulation of dendritic cells JF - Nature Communications N2 - Aberrant immune responses represent the underlying cause of central nervous system (CNS) autoimmunity, including multiple sclerosis (MS). Recent evidence implicated the crosstalk between coagulation and immunity in CNS autoimmunity. Here we identify coagulation factor XII (FXII), the initiator of the intrinsic coagulation cascade and the kallikrein–kinin system, as a specific immune cell modulator. High levels of FXII activity are present in the plasma of MS patients during relapse. Deficiency or pharmacologic blockade of FXII renders mice less susceptible to experimental autoimmune encephalomyelitis (a model of MS) and is accompanied by reduced numbers of interleukin-17A-producing T cells. Immune activation by FXII is mediated by dendritic cells in a CD87-dependent manner and involves alterations in intracellular cyclic AMP formation. Our study demonstrates that a member of the plasmatic coagulation cascade is a key mediator of autoimmunity. FXII inhibition may provide a strategy to combat MS and other immune-related disorders. KW - blood coagulation KW - factor XII KW - neuroinflammation KW - dendric cells Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165503 VL - 7 IS - 11626 ER - TY - JOUR A1 - Schuhmann, Michael K. A1 - Guthmann, Josua A1 - Stoll, Guido A1 - Nieswandt, Bernhard A1 - Kraft, Peter A1 - Kleinschnitz, Christoph T1 - Blocking of platelet glycoprotein receptor Ib reduces “thrombo-inflammation” in mice with acute ischemic stroke JF - Journal of Neuroinflammation N2 - Background: Ischemic stroke causes a strong inflammatory response that includes T cells, monocytes/macrophages, and neutrophils. Interaction of these immune cells with platelets and endothelial cells facilitates microvascular dysfunction and leads to secondary infarct growth. We recently showed that blocking of platelet glycoprotein (GP) receptor Ib improves stroke outcome without increasing the risk of intracerebral hemorrhage. Until now, it has been unclear whether GPIb only mediates thrombus formation or also contributes to the pathophysiology of local inflammation. Methods: Focal cerebral ischemia was induced in C57BL/6 mice by a 60-min transient middle cerebral artery occlusion (tMCAO). Animals were treated with antigen-binding fragments (Fab) against the platelet surface molecules GPIb (p0p/B Fab). Rat immunoglobulin G (IgG) Fab was used as control treatment. Stroke outcome, including infarct size and functional deficits as well as the local inflammatory response, was assessed on day 1 after tMCAO. Results: Blocking of GPIb reduced stroke size and improved functional outcome on day 1 after tMCAO without increasing the risk of intracerebral hemorrhage. As expected, disruption of GPIb-mediated pathways in platelets significantly reduced thrombus burden in the cerebral microvasculature. In addition, inhibition of GPIb limited the local inflammatory response in the ischemic brain as indicated by lower numbers of infiltrating T cells and macrophages and lower expression levels of inflammatory cytokines compared with rat IgG Fab-treated controls. Conclusion: In acute ischemic stroke, thrombus formation and inflammation are closely intertwined (“thrombo-inflammation”). Blocking of platelet GPIb can ameliorate thrombo-inflammation. KW - ischemic stroke KW - occlusion KW - transient middle cerebral artery KW - glycoprotein receptor Ib KW - thrombo-inflammation Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-157582 VL - 14 IS - 18 ER - TY - JOUR A1 - Albert-Weissenberger, Christiane A1 - Stetter, Christian A1 - Meuth, Sven G. A1 - Göbel, Kerstin A1 - Bader, Michael A1 - Sirén, Anna-Leena A1 - Kleinschnitz, Christoph T1 - Blocking of Bradykinin Receptor B1 Protects from Focal Closed Head Injury in Mice by Reducing Axonal Damage and Astroglia Activation JF - Journal of Cerebral Blood Flow and Metabolism N2 - The two bradykinin receptors B1R and B2R are central components of the kallikrein–kinin system with different expression kinetics and binding characteristics. Activation of these receptors by kinins triggers inflammatory responses in the target organ and in most situations enhances tissue damage. We could recently show that blocking of B1R, but not B2R, protects from cortical cryolesion by reducing inflammation and edema formation. In the present study, we investigated the role of B1R and B2R in a closed head model of focal traumatic brain injury (TBI; weight drop). Increased expression of B1R in the injured hemispheres of wild-type mice was restricted to the later stages after brain trauma, i.e. day 7 (P<0.05), whereas no significant induction could be observed for the B2R (P>0.05). Mice lacking the B1R, but not the B2R, showed less functional deficits on day 3 (P<0.001) and day 7 (P<0.001) compared with controls. Pharmacological blocking of B1R in wild-type mice had similar effects. Reduced axonal injury and astroglia activation could be identified as underlying mechanisms, while inhibition of B1R had only little influence on the local inflammatory response in this model. Inhibition of B1R may become a novel strategy to counteract trauma-induced neurodegeneration. KW - R-715 KW - kinin receptors KW - closed head injury KW - β-APP KW - astrocytes KW - TNF-α Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125903 VL - 32 IS - 9 ER - TY - JOUR A1 - Schuhmann, Michael K. A1 - Langhauser, Friederike A1 - Kraft, Peter A1 - Kleinschnitz, Christoph T1 - B cells do not have a major pathophysiologic role in acute ischemic stroke in mice JF - Journal of Neuroinflammation N2 - Background Lymphocytes have been shown to play an important role in the pathophysiology of acute ischemic stroke, but the properties of B cells remain controversial. The aim of this study was to unravel the role of B cells during acute cerebral ischemia using pharmacologic B cell depletion, B cell transgenic mice, and adoptive B cell transfer experiments. Methods Transient middle cerebral artery occlusion (60 min) was induced in wild-type mice treated with an anti-CD20 antibody 24 h before stroke onset, JHD\(^{−/−}\) mice and Rag1\(^{−/−}\) mice 24 h after adoptive B cell transfer. Stroke outcome was assessed at days 1 and 3. Infarct volumes were calculated from 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain sections, and neurological scores were evaluated. The local inflammatory response was determined by real-time PCR and immunohistochemistry. Apoptosis was analyzed by TUNEL staining, and astrocyte activation was revealed using immunohistochemistry and Western blot. Results Pharmacologic depletion of B cells did not influence infarct volumes and functional outcome at day 1 after stroke. Additionally, lack of circulating B cells in JHD\(^{−/−}\) mice also failed to influence stroke outcome at days 1 and 3. Furthermore, reconstitution of Rag1\(^{−/−}\) mice with B cells had no influence on infarct volumes. Conclusion Targeting B cells in experimental stroke did not influence lesion volume and functional outcome during the acute phase. Our findings argue against a major pathophysiologic role of B cells during acute ischemic stroke. KW - ischemic stroke KW - transient middle cerebral artery occlusion KW - B cells Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158155 VL - 14 IS - 112 ER -