Kerstin Göbel

Publications of Kerstin Göbel

• Blocking of bradykinin receptor B1 protects from focal closed head injury in mice by reducing axonal damage and astroglia activation.

  Authors: Christiane Albert-Weissenberger, Christian Stetter, Sven G Meuth, Kerstin Göbel, Michael Bader, Anna-Leena Sirén, Christoph Kleinschnitz

  Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. 05/2012;

  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 kininsThe 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.Journal of Cerebral Blood Flow & Metabolism advance online publication, 9 May 2012; doi:10.1038/jcbfm.2012.62.

• CD4+ CD25+ FoxP3+ regulatory T cells suppress cytotoxicity of CD8+ effector T cells: implications for their capacity to limit inflammatory central nervous system damage at the parenchymal level.

  Authors: Kerstin Göbel, Stefan Bittner, Nico Melzer, Susann Pankratz, Angela Dreykluft, Michael K Schuhmann, Sven G Meuth, Heinz Wiendl

  Journal of neuroinflammation. 02/2012; 9:41.

  ABSTRACT: CD4+ CD25+ forkhead box P3 (FoxP3)+ regulatory T cells (T reg cells) are known to suppress adaptive immune responses, key control tolerance and autoimmunity. We challenged the role of CD4+ABSTRACT: CD4+ CD25+ forkhead box P3 (FoxP3)+ regulatory T cells (T reg cells) are known to suppress adaptive immune responses, key control tolerance and autoimmunity. We challenged the role of CD4+ T reg cells in suppressing established CD8+ T effector cell responses by using the OT-I/II system in vitro and an OT-I-mediated, oligodendrocyte directed ex vivo model (ODC-OVA model). CD4+ T reg cells dampened cytotoxicity of an ongoing CD8+ T effector cell attack in vitro and within intact central nervous system tissue ex vivo. However, their suppressive effect was limited by the strength of the antigen signal delivered to the CD8+ T effector cells and the ratio of regulatory to effector T cells. CD8+ T effector cell suppression required T cell receptor-mediated activation together with costimulation of CD4+ T reg cells, but following activation, suppression did not require restimulation and was antigen non-specific. Our results suggest that CD4+ T reg cells are capable of suppressing CD8+ T effector cell responses at the parenchymal site, that is, limiting parenchymal damage in autoimmune central nervous system inflammation.

• Volume regulation of murine T lymphocytes relies on voltage-dependent and two-pore domain potassium channels.

  Authors: Nicole Bobak, Stefan Bittner, Joseph Andronic, Susanne Hartmann, Friederike Mühlpfordt, Tilman Schneider-Hohendorf, Karen Wolf, Carsten Schmelter, Kerstin Göbel, Patrick Meuth, Heiko Zimmermann, Frank Döring, Erhard Wischmeyer, Thomas Budde, Heinz Wiendl, Sven G Meuth, Vladimir L Sukhorukov

  Biochimica et biophysica acta. 08/2011; 1808(8):2036-44.

  A variety of ion channels are supposed to orchestrate the homoeostatic volume regulation in T lymphocytes. However, the relative contribution of different potassium channels to the osmotic volumeA variety of ion channels are supposed to orchestrate the homoeostatic volume regulation in T lymphocytes. However, the relative contribution of different potassium channels to the osmotic volume regulation and in particular to the regulatory volume decrease (RVD) in T cells is far from clear. This study explores a putative role of the newly identified K(2P) channels (TASK1, TASK2, TASK3 and TRESK) along with the voltage-gated potassium channel K(V)1.3 and the calcium-activated potassium channel K(Ca)3.1 in the RVD of murine T lymphocytes, using genetic and pharmacological approaches. K(2P) channel knockouts exerted profound effects on the osmotic properties of murine T lymphocytes, as revealed by reduced water and RVD-related solute permeabilities. Moreover, both genetic and pharmacological data proved a key role of K(V)1.3 and TASK2 channels in the RVD of murine T cells exposed to hypotonic saline. Our experiments demonstrate a leading role of potassium channels in the osmoregulation of T lymphocytes under different conditions. In summary, the present study sheds new light on the complex and partially redundant network of potassium channels involved in the basic physiological process of the cellular volume homeostasis and extends the repertoire of potassium channels by the family of K(2P) channels.

• Natalizumab restores evoked potential abnormalities in patients with relapsing-remitting multiple sclerosis.

  Authors: Sven G Meuth, Stefan Bittner, Carola Seiler, Kerstin Göbel, Heinz Wiendl

  Multiple sclerosis (Houndmills, Basingstoke, England). 02/2011; 17(2):198-203.

  The objective of this study was to examine the effects of natalizumab on functional parameters assessed by evoked potentials (visual [VEP], somatosensory [SEP] and motor evoked potentials [MEP]) in aThe objective of this study was to examine the effects of natalizumab on functional parameters assessed by evoked potentials (visual [VEP], somatosensory [SEP] and motor evoked potentials [MEP]) in a cohort study in relapsing-remitting multiple sclerosis patients. EP data of 44 patients examined 12 months prior to natalizumab treatment, at the timepoint of treatment initiation and 1 year later were compared. Sum scores (VEP, MEP, SEP) were evaluated and correlated with the Expanded Disability Status Scale. Improvement of the VEP sum score was found in 33% of natalizumab-treated patients but only in 9% of the same patients prior to treatment (p = 0.041). A comparable situation was found for SEP (improvement: 32% versus 5%; worsening: 11% versus 37%; p = 0.027). For MEP no significant differences were seen (improvement: 10% versus 18%; worsening: 5% versus 29%; p = 0.60). EP recordings (VEP = SEP > MEP) have the capacity to demonstrate treatment effects of natalizumab on a functional level. Natalizumab therapy increases the percentage of patients showing stable or even ameliorated electrophysiological parameters in the investigated functional systems.

• Expression of K2P5.1 potassium channels on CD4+ T lymphocytes correlates with disease activity in rheumatoid arthritis patients.

  Authors: Stefan Bittner, Nicole Bobak, Martin Feuchtenberger, Alexander M Herrmann, Kerstin Göbel, Raimund W Kinne, Anker J Hansen, Thomas Budde, Christoph Kleinschnitz, Oliver Frey, Hans-Peter Tony, Heinz Wiendl, Sven G Meuth

  Arthritis research & therapy. 02/2011; 13(1):R21.

  CD4+ T cells express K(2P)5.1 (TWIK-related acid-sensitive potassium channel 2 (TASK2); KCNK5), a member of the two-pore domain potassium channel family, which has been shown to influence T cellCD4+ T cells express K(2P)5.1 (TWIK-related acid-sensitive potassium channel 2 (TASK2); KCNK5), a member of the two-pore domain potassium channel family, which has been shown to influence T cell effector functions. Recently, it was shown that K(2P)5.1 is upregulated upon (autoimmune) T cell stimulation. The aim of this study was to correlate expression levels of K(2P)5.1 on T cells from patients with rheumatoid arthritis (RA) to disease activity in these patients. Expression levels of K(2P)5.1 were measured by RT-PCR in the peripheral blood of 58 patients with RA and correlated with disease activity parameters (C-reactive protein levels, erythrocyte sedimentation rates, disease activity score (DAS28) scores). Twenty patients undergoing therapy change were followed-up for six months. Additionally, synovial fluid and synovial biopsies were investigated for T lymphocytes expressing K(2P)5.1. K(2P)5.1 expression levels in CD4+ T cells show a strong correlation to DAS28 scores in RA patients. Similar correlations were found for serological inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein). In addition, K(2P)5.1 expression levels of synovial fluid-derived T cells are higher compared to peripheral blood T cells. Prospective data in individual patients show a parallel behaviour of K(2P)5.1 expression to disease activity parameters during a longitudinal follow-up for six months. Disease activity in RA patients correlates strongly with K(2P)5.1 expression levels in CD4+ T lymphocytes in the peripheral blood in cross-sectional as well as in longitudinal observations. Further studies are needed to investigate the exact pathophysiological mechanisms and to evaluate the possible use of K(2P)5.1 as a potential biomarker for disease activity and differential diagnosis.

• Glucocorticoid insensitivity at the hypoxic blood-brain barrier can be reversed by inhibition of the proteasome.

  Authors: Christoph Kleinschnitz, Kinga Blecharz, Timo Kahles, Tobias Schwarz, Peter Kraft, Kerstin Göbel, Sven G Meuth, Malgorzata Burek, Thomas Thum, Guido Stoll, Carola Förster

  Stroke; a journal of cerebral circulation. 02/2011; 42(4):1081-9.

  Glucocorticoids potently stabilize the blood-brain barrier and ameliorate tissue edema in certain neoplastic and inflammatory disorders of the central nervous system, but they are largely ineffectiveGlucocorticoids potently stabilize the blood-brain barrier and ameliorate tissue edema in certain neoplastic and inflammatory disorders of the central nervous system, but they are largely ineffective in patients with acute ischemic stroke. The reasons for this discrepancy are unresolved. To address the molecular basis for the paradox unresponsiveness of the blood-brain barrier during hypoxia, we used murine brain microvascular endothelial cells exposed to O(2)/glucose deprivation as an in vitro model. In an in vivo approach, mice were subjected to transient middle cerebral artery occlusion to induce brain infarctions. Blood-brain barrier damage and edema formation were chosen as surrogate markers of glucocorticoid sensitivity in the presence or absence of proteasome inhibitors. O(2)/glucose deprivation reduced the expression of tight junction proteins and transendothelial resistance in murine brain microvascular endothelial cells in vitro. Dexamethasone treatment failed to reverse these effects during hypoxia. Proteasome-dependent degradation of the glucocorticoid receptor impaired glucocorticoid receptor transactivation thereby preventing physiological glucocorticoid activity. Inhibition of the proteasome, however, fully restored the blood-brain barrier stabilizing properties of glucocorticoid during O(2)/glucose deprivation. Importantly, mice treated with the proteasome inhibitor Bortezomib in combination with steroids several hours after stroke developed significantly less brain edema and functional deficits, whereas respective monotherapies were ineffective. We for the first time show that inhibition of the proteasome can overcome glucocorticoid resistance at the hypoxic blood-brain barrier. Hence, combined treatment strategies may help to combat stroke-induced brain edema formation in the future and prevent secondary clinical deterioration.

• Blockade of the kinin receptor B1 protects from autoimmune CNS disease by reducing leukocyte trafficking.

  Authors: Kerstin Göbel, Susann Pankratz, Tilman Schneider-Hohendorf, Stefan Bittner, Michael K Schuhmann, Harald F Langer, Guido Stoll, Heinz Wiendl, Christoph Kleinschnitz, Sven G Meuth

  Journal of autoimmunity. 01/2011; 36(2):106-14.

  Disruption of the blood brain barrier (BBB) and transendothelial trafficking of immune cells into the central nervous system (CNS) are pathophysiological hallmarks of Multiple Sclerosis (MS) and itsDisruption of the blood brain barrier (BBB) and transendothelial trafficking of immune cells into the central nervous system (CNS) are pathophysiological hallmarks of Multiple Sclerosis (MS) and its animal model, Experimental Autoimmune Encephalomyelitis (EAE). Kinins are proinflammatory peptides which are released during tissue injury including EAE. They increase vascular permeability and enhance inflammation by acting on distinct bradykinin receptors, B1R and B2R. We studied the expression of B1R and B2R and the effect of their inhibition on the disease course, BBB integrity and T cell migration following myelin oligodendrocyte glycoprotein (MOG(35-55))-induced EAE. B1R, but not B2R expression was markedly enhanced in inflammatory CNS lesions in mice and humans. Brain endothelial cells could be identified as major source of B1R protein. The severity of EAE was significantly alleviated in B1R(-/-) mice compared with wild-type (WT) controls (P<0.05). Treatment of WT mice with the B1R antagonist R715 before and after disease onset was equally effective (P<0.05) while B1R activation by R838 promoted EAE (P<0.05). B1R inhibition was accompanied by a remarkable reduction of BBB disruption and tissue inflammation. In vitro analyses revealed that B1R suppression reverses the upregulation of ICAM-I and VCAM-I at the inflamed BBB thereby limiting T cell transmigration. In contrast, blocking B2R had no significant impact on EAE. We conclude that B1R inhibition can reduce BBB damage and cell invasion during autoimmune CNS disease and may offer a novel anti-inflammatory strategy for the treatment of MS.

• Active immunization with proteolipid protein (190-209) induces ascending paralysing experimental autoimmune encephalomyelitis in C3H/HeJ mice.

  Authors: Kerstin Göbel, Stefan Bittner, Tobias Ruck, Thomas Budde, Erhard Wischmeyer, Frank Döring, Heinz Wiendl, Sven G Meuth

  Journal of immunological methods. 12/2010; 367(1-2):27-32.

  Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system (CNS) that shares clinical and pathophysiological feature with multiple sclerosis (MS) and isExperimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system (CNS) that shares clinical and pathophysiological feature with multiple sclerosis (MS) and is commonly used as an animal model for the human disease. Upon active immunization, different myelin proteins and other neuronal antigens are known to induce EAE in susceptible mouse strains. However, there are rodent strains reputed to be resistant to actively-induced EAE and the correct combination of animal strains and their respective autoantigen is absolutely critical as some antigens are encephalitogenic in one animal strain, but not in another. Here we describe actively-induced EAE in C3H/HeJ mice with different myelin peptides. Whereas no clinical signs could be found by immunization with myelin oligodendrocyte glycoprotein 35-55, significant weight loss as well as rapidly occurring severe ascending paralysis was found in animals immunized with proteolipid protein 190-209 (PLP(190-209)). Histologically, this form of EAE was characterized by predominant involvement of the spinal cord. As PLP is one of the major lipid antigens putatively involved in the pathogenesis of MS, this model may be useful for further studies of the disease.

• Glatiramer acetate attenuates pro-inflammatory T cell responses but does not directly protect neurons from inflammatory cell death.

  Authors: Alexander M Herrmann, Kerstin Göbel, Ole J Simon, Nico Melzer, Michael K Schuhmann, Max-Philipp Stenner, Andreas Weishaupt, Christoph Kleinschnitz, Stefan Bittner, Patrick Meuth, Olaf Stuve, Thomas Budde, Bernd C Kieseier, Heinz Wiendl, Sven G Meuth

  The American journal of pathology. 10/2010; 177(6):3051-60.

  Glatiramer acetate (GA) is a synthetic, random, basic copolymer capable of modulating adaptive T cell responses. In animal models of various inflammatory and degenerative central nervous systemGlatiramer acetate (GA) is a synthetic, random, basic copolymer capable of modulating adaptive T cell responses. In animal models of various inflammatory and degenerative central nervous system disorders, GA-induced T cells cross the blood-brain barrier, secrete high levels of anti-inflammatory cytokines and neurotrophins, and thus both reduce neuronal damage and promote neurogenesis. Recently, it has been suggested that GA itself may permeate the (impaired) blood-brain-barrier and directly protect neurons under conditions of inflammation-mediated neurodegeneration. To test this hypothesis, we examined the direct effects of GA on neuronal functionality and T cell-mediated neuronal apoptosis in culture, acute brain slices, and focal experimental autoimmune encephalomyelitis. GA caused a depolarization of the resting membrane potential and led to an immediate impairment of action potential generation in neurons. Moreover, GA-incubated neurons underwent dose-dependent apoptosis. Apoptosis of ovalbumin peptide-loaded major histocompatibility complex class I-expressing neurons induced by ovalbumin-specific effector T cells could be reduced by pre-incubation of T cells, but not neurons with GA. Similar results could be found using acute brain slices. In focal experimental autoimmune encephalomyelitis, lesion size and neuronal apoptosis could be limited by pretreating rats with GA, whereas intracerebral GA application into the inflammatory lesion had no effect on neuronal survival. Our data suggest that GA attenuates adaptive pro-inflammatory T cell responses, but does not exert direct neuroprotective effects.

• Upregulation of K2P5.1 potassium channels in multiple sclerosis.

  Authors: Stefan Bittner, Nicole Bobak, Alexander M Herrmann, Kerstin Göbel, Patrick Meuth, Karin G Höhn, Max-Philipp Stenner, Thomas Budde, Heinz Wiendl, Sven G Meuth

  Annals of neurology. 07/2010; 68(1):58-69.

  Activation of T cells critically depends on potassium channels. We here characterize the impact of K(2P)5.1 (KCNK5; TASK2), a member of the 2-pore domain family of potassium channels, on T-cellActivation of T cells critically depends on potassium channels. We here characterize the impact of K(2P)5.1 (KCNK5; TASK2), a member of the 2-pore domain family of potassium channels, on T-cell function and demonstrate its putative relevance in a T-cell-mediated autoimmune disorder, multiple sclerosis (MS). Expression of K(2P)5.1 was investigated on RNA and protein level in different immune cells and in MS patients' biospecimens (peripheral blood mononuclear cells, cerebrospinal fluid cells, brain tissue specimen). Functional consequences of K(2P)5.1 expression were analyzed using pharmacological modulation, small interfering RNA (siRNA), overexpression, electrophysiological recordings, and computer modeling. Human T cells constitutively express K(2P)5.1. After T-cell activation, a significant and time-dependent upregulation of K(2P)5.1 channel expression was observed. Pharmacological blockade of K(2P)5.1 or knockdown with siRNA resulted in reduced T-cell functions, whereas overexpression of K(2P)5.1 had the opposite effect. Electrophysiological recordings of T cells clearly dissected K(2P)5.1-mediated effects from other potassium channels. The pathophysiological relevance of these findings was demonstrated by a significant K(2P)5.1 upregulation in CD4(+) and CD8(+) T cells in relapsing/remitting MS (RRMS) patients during acute relapses as well as higher levels on CD8(+) T cells of clinically isolated syndrome, RRMS, and secondary progressive multiple sclerosis patients during clinically stable disease. T cells in the cerebrospinal fluid from MS patients exhibit significantly elevated K(2P)5.1 levels. Furthermore, K(2P)5.1-positive T cells can be found in inflammatory lesions in MS tissue specimens. Selective targeting of K(2P)5.1 may hold therapeutic promise for MS and putatively other T-cell-mediated disorders.

• Deficiency of the negative immune regulator B7-H1 enhances inflammation and neuropathic pain after chronic constriction injury of mouse sciatic nerve.

  Authors: Nurcan Uçeyler, Kerstin Göbel, Sven G Meuth, Sonja Ortler, Guido Stoll, Claudia Sommer, Heinz Wiendl, Christoph Kleinschnitz

  Experimental neurology. 03/2010; 222(1):153-60.

  Peripheral nerve injury induces a profound local inflammatory response that involves T cells and macrophages and augments the generation of neuropathic pain. The mechanisms underlying immune cellPeripheral nerve injury induces a profound local inflammatory response that involves T cells and macrophages and augments the generation of neuropathic pain. The mechanisms underlying immune cell activation or inhibition in the peripheral nervous system, however, are unknown. The co-inhibitory molecule B7-H1 (PD-L1, CD274) attenuates immune cell proliferation and cytokine production and protects from inflammation-induced tissue damage. We analyzed the temporal gene expression profile of B7-H1 and different cytokines after chronic constriction injury (CCI) of the sciatic nerve, a lesion paradigm inducing neuropathic pain, by quantitative real-time polymerase chain reaction and immunohistochemistry in B7-H1(-/-) mice and wild-type (WT) controls. B7-H1 mRNA was markedly induced in WT nerves after CCI, and macrophages could be identified as major B7-H1 source. The proinflammatory mediators tumor necrosis factor alpha (TNFalpha) and monocyte chemoattractant protein-1 (MCP-1) displayed a strong, but transient expression in degenerating nerves on day 1 after CCI in WT mice, while a biphasic expression peak on day 1 and day 28 was found in B7-H1(-/-) mice. Overall, TNFalpha and MCP-1 levels in B7-H1-deficient nerves dramatically exceeded those in WT controls. In contrast, induction of the anti-inflammatory cytokine interleukin(IL)-10 was restricted to WT nerves. The observation that B7-H1 deficiency enhances inflammation upon CCI was further corroborated by immunohistochemistry showing increased numbers of T cells and macrophages in injured nerves from B7-H1(-/-) mice. Interestingly, mechanical hyperalgesia was more pronounced in the absence of B7-H1. Our study identifies B7-H1 as an important suppressor of the inflammatory response and neuropathic pain occurring after peripheral nerve injury.

• Temporal pattern of ICAM-I mediated regulatory T cell recruitment to sites of inflammation in adoptive transfer model of multiple sclerosis.

  Authors: Sebastian Doerck, Kerstin Göbel, Gesa Weise, Tilman Schneider-Hohendorf, Michael Reinhardt, Peter Hauff, Nicholas Schwab, Ralf Linker, Mathias Mäurer, Sven G Meuth, Heinz Wiendl

  PloS one. 01/2010; 5(11):e15478.

  Migration of immune cells to the target organ plays a key role in autoimmune disorders like multiple sclerosis (MS). However, the exact underlying mechanisms of this active process during autoimmuneMigration of immune cells to the target organ plays a key role in autoimmune disorders like multiple sclerosis (MS). However, the exact underlying mechanisms of this active process during autoimmune lesion pathogenesis remain elusive. To test if pro-inflammatory and regulatory T cells migrate via a similar molecular mechanism, we analyzed the expression of different adhesion molecules, as well as the composition of infiltrating T cells in an in vivo model of MS, adoptive transfer experimental autoimmune encephalomyelitis in rats. We found that the upregulation of ICAM-I and VCAM-I parallels the development of clinical disease onset, but persists on elevated levels also in the phase of clinical remission. However, the composition of infiltrating T cells found in the developing versus resolving lesion phase changed over time, containing increased numbers of regulatory T cells (FoxP3) only in the phase of clinical remission. In order to test the relevance of the expression of cell adhesion molecules, animals were treated with purified antibodies to ICAM-I and VCAM-I either in the phase of active disease or in early remission. Treatment with a blocking ICAM-I antibody in the phase of disease progression led to a milder disease course. However, administration during early clinical remission aggravates clinical symptoms. Treatment with anti-VCAM-I at different timepoints had no significant effect on the disease course. In summary, our results indicate that adhesion molecules are not only important for capture and migration of pro-inflammatory T cells into the central nervous system, but also permit access of anti-inflammatory cells, such as regulatory T cells. Therefore it is likely to assume that intervention at the blood brain barrier is time dependent and could result in different therapeutic outcomes depending on the phase of CNS lesion development.

• Collateral neuronal apoptosis in CNS gray matter during an oligodendrocyte-directed CD8(+) T cell attack.

  Authors: Kerstin Göbel, Nico Melzer, Alexander M Herrmann, Michael K Schuhmann, Stefan Bittner, Chi Wang Ip, Thomas Hünig, Sven G Meuth, Heinz Wiendl

  Glia. 09/2009;

  Demyelination and death of oligodendrocytes accompanied by transection of neurites and neuronal apoptosis are pathological hallmarks of cortical and subcortical gray matter lesions in demyelinatingDemyelination and death of oligodendrocytes accompanied by transection of neurites and neuronal apoptosis are pathological hallmarks of cortical and subcortical gray matter lesions in demyelinating viral and autoimmune inflammatory CNS disorders. In these disorders, leukocortical lesions, containing the perikarya of most efferent neurons, display pronounced infiltration by CD8(+) T cells of putative specificity for oligodendrocyte- and myelin-related antigens. Hence, neuronal apoptosis in gray matter lesions may be a collateral effect of an oligodendrocyte-directed attack by CD8(+) T cells. To challenge this hypothesis, we transferred activated antigen-specific CD8(+) T cells (OT-I T cells) into acute coronal brain slices from mice selectively expressing ovalbumin as a cytosolic neo-self-antigen in oligodendrocytes (ODC-OVA mice). We studied mechanisms and kinetics of oligodendroglial and neuronal apoptosis in the neocortex and hippocampus, using multicolor staining for different cell types and activated caspase-3. Within the gray matter, a single OT-I T cell caused simultaneous caspase-3 activation in about 30 ODCs and 10 neurons within 6 h in a strictly antigen-dependent manner. Experiments with OT-I T cells genetically deficient for perforin or the granzyme B-cluster and with blocking anti-FasL antibodies as well as proinflammatory cytokines revealed, that collateral apoptosis of neurons was likely due to a spillover of perforin and granzyme(s) from the OT-I T cell itself or the immunological synapse that it selectively formed with antigen-presenting oligodendrocytes. Collateral neuronal apoptosis could contribute to substantial neuronal loss in gray matter lesions and cause persistent neurological impairment in both acute and chronic gray matter lesions in various inflammatory CNS disorders. (c) 2009 Wiley-Liss, Inc.

• TASK1 modulates inflammation and neurodegeneration in autoimmune inflammation of the central nervous system.

  Authors: Stefan Bittner, Sven G Meuth, Kerstin Göbel, Nico Melzer, Alexander M Herrmann, Ole J Simon, Andreas Weishaupt, Thomas Budde, Douglas A Bayliss, Martin Bendszus, Heinz Wiendl

  Brain : a journal of neurology. 08/2009;

  We provide evidence that TWIK-related acid-sensitive potassium channel 1 (TASK1), a member of the family of two-pore domain potassium channels relevant for setting the resting membrane potential andWe provide evidence that TWIK-related acid-sensitive potassium channel 1 (TASK1), a member of the family of two-pore domain potassium channels relevant for setting the resting membrane potential and balancing neuronal excitability that is expressed on T cells and neurons, is a key modulator of T cell immunity and neurodegeneration in autoimmune central nervous system inflammation. After induction of experimental autoimmune encephalomyelitis, an experimental model mimicking multiple sclerosis, TASK1(-/-) mice showed a significantly reduced clinical severity and markedly reduced axonal degeneration compared with wild-type controls. T cells from TASK1(-/-) mice displayed impaired T cell proliferation and cytokine production, while the immune repertoire is otherwise normal. In addition to these effects on systemic T cell responses, TASK1 exhibits an independent neuroprotective effect which was demonstrated using both a model of acutely prepared brain slices cocultured with activated T cells as well as in vitro cultivation experiments with isolated optic nerves. Anandamide, an endogenous cannabinoid and inhibitor of TASK channels, reduced outward currents and inhibited effector functions of T cells (IFN-gamma production and proliferation); an effect completely abrogated in TASK1(-/-) mice. Accordingly, preventive blockade of TASK1 significantly ameliorated experimental autoimmune encephalomyelitis after immunization. Therapeutic application of anandamide significantly reduced disease severity and was capable of lowering progressive loss of brain parenchymal volume as assessed by magnetic resonance imaging. These data support the identification and characterization of TASK1 as potential molecular target for the therapy of inflammatory and degenerative central nervous system disorders.

• Accelerated Course of Experimental Autoimmune Encephalomyelitis in PD-1-Deficient Central Nervous System Myelin Mutants.

  Authors: Antje Kroner, Nicholas Schwab, Chi Wang Ip, Sonja Ortler, Kerstin Göbel, Klaus-Armin Nave, Mathias Mäurer, Rudolf Martini, Heinz Wiendl

  The American journal of pathology. 06/2009;

  It is assumed that the onset and course of autoimmune inflammatory central nervous system (CNS) disorders (eg, multiple sclerosis) are influenced by factors that afflict immune regulation as well asIt is assumed that the onset and course of autoimmune inflammatory central nervous system (CNS) disorders (eg, multiple sclerosis) are influenced by factors that afflict immune regulation as well as CNS vulnerability. We challenged this concept experimentally by investigating how genetic alterations that affect myelin (primary oligodendrocyte damage in PLPtg mice) and/or T-cell regulation (deficiency of PD-1) influence both the onset and course of an experimental autoimmune CNS inflammatory disease [MOG35-55-induced experimental autoimmune encephalomyelitis (EAE)]. We observed that double pathology was associated with a significantly earlier onset of disease, a slight increase in the neurological score, an increase in the number of infiltrating cells, and enhanced axonal degeneration compared with wild-type mice and the respective, single mutant controls. Double-mutant PLPtg/PD-1(-/-) mice showed an increased production of interferon-gamma by CNS immune cells at the peak of disease. Neither PD-1 deficiency nor oligodendropathy led to detectable spread of antigenic MHC class I- or class II-restricted epitopes during EAE. However, absence of PD-1 clearly increased the propensity of T lymphocytes to expand, and the number of clonal expansions reliably reflected the severity of the EAE disease course. Our data show that the interplay between immune dysregulation and myelinopathy results in a stable exacerbation of actively induced autoimmune CNS inflammation, suggesting that the combination of several pathological issues contributes significantly to disease susceptibility or relapses in human disease.

• Antigen-specific blockade of lethal CD8 T-cell mediated autoimmunity in a mouse model of multiple sclerosis.

  Authors: Shin-Young Na, Heike Eujen, Kerstin Göbel, Sven G Meuth, Kati Martens, Heinz Wiendl, Thomas Hünig

  Journal of immunology (Baltimore, Md. : 1950). 06/2009; 182(10):6569-75.

  Increasing evidence implies CD8 T cells in tissue-specific autoimmune diseases including multiple sclerosis. mAbs specific for MHC class I molecules presenting a dominant autoantigenic peptide mayIncreasing evidence implies CD8 T cells in tissue-specific autoimmune diseases including multiple sclerosis. mAbs specific for MHC class I molecules presenting a dominant autoantigenic peptide may allow selective immunotherapy in such settings. We demonstrate the prophylactic and therapeutic efficacy of such a mAb in a transgenic mouse model of lethal demyelinating disease in which a neo-self Ag expressed by oligodendrocytes is targeted by CD8 T cells with transgenic Ag receptors. Mechanistic studies performed in vitro and in vivo indicate that it is the low expression of MHC class I on oligodendrocytes, which makes this form of Ag-specific intervention possible.

• Deficiency of the negative immune regulator B7-H1 enhances inflammation and neuropathic pain after chronic constriction injury of mouse sciatic nerve

  Authors: Nurcan Üçeyler, Kerstin Göbel, Sven G. Meuth, Sonja Ortler, Guido Stoll, Claudia Sommer, Heinz Wiendl, Christoph Kleinschnitz

  Experimental Neurology.

  Peripheral nerve injury induces a profound local inflammatory response that involves T cells and macrophages and augments the generation of neuropathic pain. The mechanisms underlying immune cellPeripheral nerve injury induces a profound local inflammatory response that involves T cells and macrophages and augments the generation of neuropathic pain. The mechanisms underlying immune cell activation or inhibition in the peripheral nervous system, however, are unknown. The co-inhibitory molecule B7-H1 (PD-L1, CD274) attenuates immune cell proliferation and cytokine production and protects from inflammation-induced tissue damage. We analyzed the temporal gene expression profile of B7-H1 and different cytokines after chronic constriction injury (CCI) of the sciatic nerve, a lesion paradigm inducing neuropathic pain, by quantitative real-time polymerase chain reaction and immunohistochemistry in B7-H1−/− mice and wild-type (WT) controls. B7-H1 mRNA was markedly induced in WT nerves after CCI, and macrophages could be identified as major B7-H1 source. The proinflammatory mediators tumor necrosis factor alpha (TNFα) and monocyte chemoattractant protein-1 (MCP-1) displayed a strong, but transient expression in degenerating nerves on day 1 after CCI in WT mice, while a biphasic expression peak on day 1 and day 28 was found in B7-H1−/− mice. Overall, TNFα and MCP-1 levels in B7-H1-deficient nerves dramatically exceeded those in WT controls. In contrast, induction of the anti-inflammatory cytokine interleukin(IL)-10 was restricted to WT nerves. The observation that B7-H1 deficiency enhances inflammation upon CCI was further corroborated by immunohistochemistry showing increased numbers of T cells and macrophages in injured nerves from B7-H1−/− mice. Interestingly, mechanical hyperalgesia was more pronounced in the absence of B7-H1. Our study identifies B7-H1 as an important suppressor of the inflammatory response and neuropathic pain occurring after peripheral nerve injury.