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Aggio V, Fabbella L, Poletti S, Lorenzi C, Finardi A, Colombo C, Zanardi R, Furlan R, Benedetti F. Circulating cytotoxic immune cell composition, activation status and toxins expression associate with white matter microstructure in bipolar disorder. Sci Rep 2023; 13:22209. [PMID: 38097657 PMCID: PMC10721611 DOI: 10.1038/s41598-023-49146-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 12/05/2023] [Indexed: 12/17/2023] Open
Abstract
Patients with bipolar disorder (BD) show higher immuno-inflammatory setpoints, with in vivo alterations in white matter (WM) microstructure and post-mortem infiltration of T cells in the brain. Cytotoxic CD8+ T cells can enter and damage the brain in inflammatory disorders, but little is known in BD. Our study aimed to investigate the relationship between cytotoxic T cells and WM alterations in BD. In a sample of 83 inpatients with BD in an active phase of illness (68 depressive, 15 manic), we performed flow cytometry immunophenotyping to investigate frequencies, activation status, and expression of cytotoxic markers in CD8+ and tested for their association with diffusion tensor imaging (DTI) measures of WM microstructure. Frequencies of naïve and activated CD8+ cell populations expressing Perforin, or both Perforin and Granzyme, negatively associated with WM microstructure. CD8+ Naïve cells negative for Granzyme and Perforin positively associates with indexes of WM integrity, while the frequency of CD8+ memory cells negatively associates with index of WM microstructure, irrespective of toxins expression. The resulting associations involve measures representative of orientational coherence and myelination of the fibers (FA and RD), suggesting disrupted oligodendrocyte-mediated myelination. These findings seems to support the hypothesis that immunosenescence (less naïve, more memory T cells) can detrimentally influence WM microstructure in BD and that peripheral CD8+ T cells may participate in inducing an immune-related WM damage in BD mediated by killer proteins.
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Affiliation(s)
- Veronica Aggio
- Psychiatry and Clinical Psychobiology Unit, Division of Neurosciences, IRCCS San Raffaele Scientific Institute, San Raffaele Turro, Via Stamira d'Ancona 20, 20127, Milano, Italy.
- Vita-Salute San Raffaele University, Milan, Italy.
| | - Lorena Fabbella
- Clinical Neuroimmunology Unit, Division of Neuroscience, Institute of Experimental Neurology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Sara Poletti
- Psychiatry and Clinical Psychobiology Unit, Division of Neurosciences, IRCCS San Raffaele Scientific Institute, San Raffaele Turro, Via Stamira d'Ancona 20, 20127, Milano, Italy
| | - Cristina Lorenzi
- Psychiatry and Clinical Psychobiology Unit, Division of Neurosciences, IRCCS San Raffaele Scientific Institute, San Raffaele Turro, Via Stamira d'Ancona 20, 20127, Milano, Italy
| | - Annamaria Finardi
- Clinical Neuroimmunology Unit, Division of Neuroscience, Institute of Experimental Neurology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Cristina Colombo
- Vita-Salute San Raffaele University, Milan, Italy
- Mood Disorders Unit, IRCCS Scientific Institute Ospedale San Raffaele, Milano, Italy
| | - Raffaella Zanardi
- Mood Disorders Unit, IRCCS Scientific Institute Ospedale San Raffaele, Milano, Italy
| | - Roberto Furlan
- Vita-Salute San Raffaele University, Milan, Italy
- Clinical Neuroimmunology Unit, Division of Neuroscience, Institute of Experimental Neurology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Benedetti
- Psychiatry and Clinical Psychobiology Unit, Division of Neurosciences, IRCCS San Raffaele Scientific Institute, San Raffaele Turro, Via Stamira d'Ancona 20, 20127, Milano, Italy
- Vita-Salute San Raffaele University, Milan, Italy
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2
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Vizcarra EA, Ulu A, Landrith TA, Qiu X, Godzik A, Wilson EH. Group 1 metabotropic glutamate receptor expression defines a T cell memory population during chronic Toxoplasma infection that enhances IFN-gamma and perforin production in the CNS. Brain Behav Immun 2023; 114:131-143. [PMID: 37604212 DOI: 10.1016/j.bbi.2023.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 08/23/2023] Open
Abstract
Within the brain, a pro-inflammatory response is essential to prevent clinical disease due to Toxoplasma gondii reactivation. Infection in the immunocompromised leads to lethal Toxoplasmic encephalitis while in the immunocompetent, there is persistent low-grade inflammation which is devoid of clinical symptoms. This signifies that there is a well-balanced and regulated inflammatory response to T. gondii in the brain. T cells are the dominant immune cells that prevent clinical disease, and this is mediated through the secretion of effector molecules such as perforins and IFN-γ. The presence of cognate antigen, the expression of survival cytokines, and the alteration of the epigenetic landscape drive the development of memory T cells. However, specific extrinsic signals that promote the formation and maintenance of memory T cells within tissue are poorly understood. During chronic infection, there is an increase in extracellular glutamate that, due to its function as an excitatory neurotransmitter, is normally tightly controlled in the CNS. Here we demonstrate that CD8+ T cells from the T. gondii-infected brain parenchyma are enriched for metabotropic glutamate receptors (mGluR's). Characterization studies determined that mGluR+ expression by CD8+ T cells defines a distinct memory population at the transcriptional and protein level. Finally, using receptor antagonists and agonists we demonstrate mGluR signaling is required for optimal CD8+ T cell production of the effector cytokine IFNγ. This work suggests that glutamate is an important environmental signal of inflammation that promotes T cell function. Understanding glutamate's influence on T cells in the brain can provide insights into the mechanisms that govern protective immunity against CNS-infiltrating pathogens and neuroinflammation.
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Affiliation(s)
- Edward A Vizcarra
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Arzu Ulu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Tyler A Landrith
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Xinru Qiu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Adam Godzik
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Emma H Wilson
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States.
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3
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Klotz L, Antel J, Kuhlmann T. Inflammation in multiple sclerosis: consequences for remyelination and disease progression. Nat Rev Neurol 2023; 19:305-320. [PMID: 37059811 DOI: 10.1038/s41582-023-00801-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2023] [Indexed: 04/16/2023]
Abstract
Despite the large number of immunomodulatory or immunosuppressive treatments available to treat relapsing-remitting multiple sclerosis (MS), treatment of the progressive phase of the disease has not yet been achieved. This lack of successful treatment approaches is caused by our poor understanding of the mechanisms driving disease progression. Emerging concepts suggest that a combination of persisting focal and diffuse inflammation within the CNS and a gradual failure of compensatory mechanisms, including remyelination, result in disease progression. Therefore, promotion of remyelination presents a promising intervention approach. However, despite our increasing knowledge regarding the cellular and molecular mechanisms regulating remyelination in animal models, therapeutic increases in remyelination remain an unmet need in MS, which suggests that mechanisms of remyelination and remyelination failure differ fundamentally between humans and demyelinating animal models. New and emerging technologies now allow us to investigate the cellular and molecular mechanisms underlying remyelination failure in human tissue samples in an unprecedented way. The aim of this Review is to summarize our current knowledge regarding mechanisms of remyelination and remyelination failure in MS and in animal models of the disease, identify open questions, challenge existing concepts, and discuss strategies to overcome the translational roadblock in the field of remyelination-promoting therapies.
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Affiliation(s)
- Luisa Klotz
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Jack Antel
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Québec, Canada
| | - Tanja Kuhlmann
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Québec, Canada.
- Institute of Neuropathology, University Hospital Münster, Münster, Germany.
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4
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Birkner K, Wasser B, Ruck T, Thalman C, Luchtman D, Pape K, Schmaul S, Bitar L, Krämer-Albers EM, Stroh A, Meuth SG, Zipp F, Bittner S. β1-Integrin- and KV1.3 channel-dependent signaling stimulates glutamate release from Th17 cells. J Clin Invest 2020; 130:715-732. [PMID: 31661467 DOI: 10.1172/jci126381] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 10/22/2019] [Indexed: 12/22/2022] Open
Abstract
Although the impact of Th17 cells on autoimmunity is undisputable, their pathogenic effector mechanism is still enigmatic. We discovered soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) complex proteins in Th17 cells that enable a vesicular glutamate release pathway that induces local intracytoplasmic calcium release and subsequent damage in neurons. This pathway is glutamine dependent and triggered by binding of β1-integrin to vascular cell adhesion molecule 1 (VCAM-1) on neurons in the inflammatory context. Glutamate secretion could be blocked by inhibiting either glutaminase or KV1.3 channels, which are known to be linked to integrin expression and highly expressed on stimulated T cells. Although KV1.3 is not expressed in CNS tissue, intrathecal administration of a KV1.3 channel blocker or a glutaminase inhibitor ameliorated disability in experimental neuroinflammation. In humans, T cells from patients with multiple sclerosis secreted higher levels of glutamate, and cerebrospinal fluid glutamine levels were increased. Altogether, our findings demonstrate that β1-integrin- and KV1.3 channel-dependent signaling stimulates glutamate release from Th17 cells upon direct cell-cell contact between Th17 cells and neurons.
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Affiliation(s)
- Katharina Birkner
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Beatrice Wasser
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Tobias Ruck
- Department of Neurology, University of Muenster, Muenster, Germany
| | - Carine Thalman
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Luchtman
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Katrin Pape
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Samantha Schmaul
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Lynn Bitar
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Albrecht Stroh
- Institute for Pathophysiology, FTN, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sven G Meuth
- Department of Neurology, University of Muenster, Muenster, Germany
| | - Frauke Zipp
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Bittner
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2, ), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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5
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Low CSF CD4/CD8+ T-cell proportions are associated with blood-CSF barrier dysfunction in limbic encephalitis. Epilepsy Behav 2020; 102:106682. [PMID: 31846897 DOI: 10.1016/j.yebeh.2019.106682] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 10/10/2019] [Accepted: 11/02/2019] [Indexed: 11/23/2022]
Abstract
PURPOSE Investigating immune cells in autoimmune limbic encephalitis (LE) will contribute to our understanding of its pathophysiology and may help to develop appropriate therapies. The aim of the present study was to analyze immune cells to reveal underlying immune signatures in patients with temporal lobe epilepsy (TLE) with LE. METHODS We investigated 68 patients with TLE with LE compared with 7 control patients with TLE with no signs of LE screened from 154 patients with suspected LE. From the patients with TLE-LE, we differentiated early seizure onset (<20 years, n = 9) and late seizure onset group (≥20 years, n = 59) of patients. Patients underwent neuropsychological assessment, electroencephalography (EEG), brain magnetic resonance imaging (MRI), and peripheral blood (PB) and cerebrospinal fluid (CSF) analysis including flow cytometry. RESULTS We identified a higher CD4/8+ T-cell ratio in the PB in all patients with TLE-LE and in patients with late-onset TLE-LE each compared with controls (Kruskal-Wallis one-way ANOVA (analysis of variance) with Dunn's test, p < 0.05). Moreover, a lower CD4/CD8+ T-cell ratio is detected in all patients with TLE-LE with blood-CSF barrier dysfunction, unlike in those with none (Kruskal-Wallis one-way ANOVA with Dunn's test, p < 0.05). CONCLUSIONS These findings suggest that the proportion of CD4+ and CD8+ T-cells in the CSF of patients with LE associated with blood-CSF barrier dysfunction plays a potential role in CNS (central nervous system) inflammation in these patients. Thus, flow cytometry as a methodology reveals novel insights into LE's genesis and symptomatology. The CD4/8+ T-cell ratio in PB as a biomarker for LE requires further investigation.
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Cerebral Ischemic Postconditioning Plays a Neuroprotective Role through Regulation of Central and Peripheral Glutamate. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6316059. [PMID: 30112410 PMCID: PMC6077516 DOI: 10.1155/2018/6316059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/12/2018] [Indexed: 01/30/2023]
Abstract
Following cerebral ischemia/reperfusion (I/R) injury, a series of pathophysiological processes are stimulated in both the central nervous system (CNS) and the periphery, including, but not limited to, the peripheral immune and endocrine systems and underregulation of the neuroendocrine-immune network. Glutamate (Glu) is an important excitatory neurotransmitter in the CNS; its excitotoxicity following cerebral ischemia has been a focus of study for several decades. In addition, as a novel immunoregulator, Glu also regulates immune activity in both the CNS and periphery and may connect the CNS and periphery through regulation of the neuroendocrine-immune network. Ischemic postconditioning (IPostC) is powerful and activates various endogenous neuroprotective mechanisms following cerebral I/R, but only a few studies have focused on the mechanisms associated with Glu to date. Given that Glu plays an important and complex pathophysiological role, the understanding of Glu-related mechanisms of IPostC is an interesting area of research, which we review here.
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Mykicki N, Herrmann AM, Schwab N, Deenen R, Sparwasser T, Limmer A, Wachsmuth L, Klotz L, Köhrer K, Faber C, Wiendl H, Luger TA, Meuth SG, Loser K. Melanocortin-1 receptor activation is neuroprotective in mouse models of neuroinflammatory disease. Sci Transl Med 2017; 8:362ra146. [PMID: 27797962 DOI: 10.1126/scitranslmed.aaf8732] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 10/07/2016] [Indexed: 12/21/2022]
Abstract
In inflammation-associated progressive neuroinflammatory disorders, such as multiple sclerosis (MS), inflammatory infiltrates containing T helper 1 (TH1) and TH17 cells cause demyelination and neuronal degeneration. Regulatory T cells (Treg) control the activation and infiltration of autoreactive T cells into the central nervous system (CNS). In MS and experimental autoimmune encephalomyelitis (EAE) in mice, Treg function is impaired. We show that a recently approved drug, Nle4-d-Phe7-α-melanocyte-stimulating hormone (NDP-MSH), induced functional Treg, resulting in amelioration of EAE progression in mice. NDP-MSH also prevented immune cell infiltration into the CNS by restoring the integrity of the blood-brain barrier. NDP-MSH exerted long-lasting neuroprotective effects in mice with EAE and prevented excitotoxic death and reestablished action potential firing in mouse and human neurons in vitro. Neuroprotection by NDP-MSH was mediated via signaling through the melanocortin-1 and orphan nuclear 4 receptors in mouse and human neurons. NDP-MSH may be of benefit in treating neuroinflammatory diseases such as relapsing-remitting MS and related disorders.
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Affiliation(s)
- Nadine Mykicki
- Department of Dermatology, University of Münster, 48149 Münster, Germany.,Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany
| | - Alexander M Herrmann
- Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany.,Department of Neurology, University of Münster, 48149 Münster, Germany
| | - Nicholas Schwab
- Department of Neurology, University of Münster, 48149 Münster, Germany
| | - René Deenen
- Biological and Medical Research Center, University of Düsseldorf, 40225 Düsseldorf, Germany
| | - Tim Sparwasser
- Institute of Infection Immunology, TWINCORE Centre for Experimental and Clinical Infection Research, 30625 Hannover, Germany
| | - Andreas Limmer
- Clinic for Orthopedic and Trauma Surgery, University Clinic of Bonn, 53127 Bonn, Germany
| | - Lydia Wachsmuth
- Department of Clinical Radiology, University of Münster, 48149 Münster, Germany
| | - Luisa Klotz
- Department of Neurology, University of Münster, 48149 Münster, Germany
| | - Karl Köhrer
- Biological and Medical Research Center, University of Düsseldorf, 40225 Düsseldorf, Germany
| | - Cornelius Faber
- Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany.,Department of Clinical Radiology, University of Münster, 48149 Münster, Germany.,CRC1009 Breaking Barriers and CRC-TR 128 Multiple Sclerosis, University of Münster, 48149 Münster, Germany
| | - Heinz Wiendl
- Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany.,Department of Neurology, University of Münster, 48149 Münster, Germany.,CRC1009 Breaking Barriers and CRC-TR 128 Multiple Sclerosis, University of Münster, 48149 Münster, Germany
| | - Thomas A Luger
- Department of Dermatology, University of Münster, 48149 Münster, Germany.,Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany
| | - Sven G Meuth
- Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany.,Department of Neurology, University of Münster, 48149 Münster, Germany.,CRC1009 Breaking Barriers and CRC-TR 128 Multiple Sclerosis, University of Münster, 48149 Münster, Germany
| | - Karin Loser
- Department of Dermatology, University of Münster, 48149 Münster, Germany. .,Cells in Motion-Cluster of Excellence, University of Münster, 48149 Münster, Germany.,CRC1009 Breaking Barriers and CRC-TR 128 Multiple Sclerosis, University of Münster, 48149 Münster, Germany
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Abstract
There is an increasing recognition that inflammation plays a critical role in neurodegenerative diseases of the CNS, including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and the prototypic neuroinflammatory disease multiple sclerosis (MS). Differential immune responses involving the adaptive versus the innate immune system are observed at various stages of neurodegenerative diseases, and may not only drive disease processes but could serve as therapeutic targets. Ongoing investigations into the specific inflammatory mechanisms that play roles in disease causation and progression have revealed lessons about inflammation-driven neurodegeneration that can be applied to other neurodegenerative diseases. An increasing number of immunotherapeutic strategies that have been successful in MS are now being applied to other neurodegenerative diseases. Some approaches suppress CNS immune mechanisms, while others harness the immune system to clear deleterious products and cells. This Review focuses on the mechanisms by which inflammation, mediated either by the peripheral immune response or by endogenous CNS immune mechanisms, can affect CNS neurodegeneration.
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9
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Levite M. Glutamate, T cells and multiple sclerosis. J Neural Transm (Vienna) 2017; 124:775-798. [PMID: 28236206 DOI: 10.1007/s00702-016-1661-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/25/2016] [Indexed: 12/18/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the nervous system, where it induces multiple beneficial and essential effects. Yet, excess glutamate, evident in a kaleidoscope of acute and chronic pathologies, is absolutely catastrophic, since it induces excitotoxicity and massive loss of brain function. Both the beneficial and the detrimental effects of glutamate are mediated by a large family of glutamate receptors (GluRs): the ionotropic glutamate receptors (iGluRs) and the metabotropic glutamate receptors (mGluRs), expressed by most/all cells of the nervous system, and also by many non-neural cells in various peripheral organs and tissues. T cells express on their cell surface several types of functional GluRs, and so do few other immune cells. Furthermore, glutamate by itself activates resting normal human T cells, and induces/elevates key T cell functions, among them: T cell adhesion, chemotactic migration, cytokine secretion, gene expression and more. Glutamate has also potent effects on antigen/mitogen/cytokine-activated T cells. Furthermore, T cells can even produce and release glutamate, and affect other cells and themselves via their own glutamate. Multiple sclerosis (MS) and its animal model Experimental Autoimmune Encephalomyelitis (EAE) are mediated by autoimmune T cells. In MS and EAE, there are excess glutamate levels, and multiple abnormalities in glutamate degrading enzymes, glutamate transporters, glutamate receptors and glutamate signaling. Some GluR antagonists block EAE. Enhancer of mGluR4 protects from EAE via regulatory T cells (Tregs), while mGluR4 deficiency exacerbates EAE. The protective effect of mGluR4 on EAE calls for testing GluR4 enhancers in MS patients. Oral MS therapeutics, namely Fingolimod, dimethyl fumarate and their respective metabolites Fingolimod-phosphate and monomethyl fumarate, can protect neurons against acute glutamatergic excitotoxic damage. Furthermore, Fingolimod reduce glutamate-mediated intracortical excitability in relapsing-remitting MS. Glatiramer acetate -COPAXONE®, an immunomodulator drug for MS, reverses TNF-α-induced alterations of striatal glutamate-mediated excitatory postsynaptic currents in EAE-afflicted mice. With regard to T cells of MS patients: (1) The cell surface expression of a specific GluR: the AMPA GluR3 is elevated in T cells of MS patients during relapse and with active disease, (2) Glutamate and AMPA (a selective agonist for glutamate/AMPA iGluRs) augment chemotactic migration of T cells of MS patients, (3) Glutamate augments proliferation of T cells of MS patients in response to myelin-derived proteins: MBP and MOG, (4) T cells of MS patients respond abnormally to glutamate, (5) Significantly higher proliferation values in response to glutamate were found in MS patients assessed during relapse, and in those with gadolinium (Gd)+ enhancing lesions on MRI. Furthermore, glutamate released from autoreactive T cells induces excitotoxic cell death of neurons. Taken together, the evidences accumulated thus far indicate that abnormal glutamate levels and signaling in the nervous system, direct activation of T cells by glutamate, and glutamate release by T cells, can all contribute to MS. This may be true also to other neurological diseases. It is postulated herein that the detrimental activation of autoimmune T cells by glutamate in MS could lead to: (1) Cytotoxicity in the CNS: T cell-mediated killing of neurons and glia cells, which would subsequently increase the extracellular glutamate levels, and by doing so increase the excitotoxicity mediated by excess glutamate, (2) Release of proinflammatory cytokines, e.g., TNFα and IFNγ that increase neuroinflammation. Finally, if excess glutamate, abnormal neuronal signaling, glutamate-induced activation of T cells, and glutamate release by T cells are indeed all playing a key detrimental role in MS, then optional therapeutic tolls include GluR antagonists, although these may have various side effects. In addition, an especially attractive therapeutic strategy is the novel and entirely different therapeutic approach to minimize excess glutamate and excitotoxicity, titled: 'brain to blood glutamate scavenging', designed to lower excess glutamate levels in the CNS by 'pumping it out' from the brain to the blood. The glutamate scavanging is achieved by lowering glutamate levels in the blood by intravenous injection of the blood enzyme glutamate oxaloacetate transaminase (GOT). The glutamate-scavenging technology, which is still experimental, validated so far for other brain pathologies, but not tested on MS or EAE yet, may be beneficial for MS too, since it could decrease both the deleterious effects of excess glutamate on neural cells, and the activation of autoimmune T cells by glutamate in the brain. The topic of glutamate scavenging, and also its potential benefit for MS, are discussed towards the end of the review, and call for research in this direction.
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Affiliation(s)
- Mia Levite
- Faculty of Medicine, School of Pharmacy, The Hebrew University, Jerusalem, Israel. .,Institute of Gene Therapy, Hadassah Medical Center, 91120, Ein Karem, Jerusalem, Israel.
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10
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Protective Effects of Glutamine Antagonist 6-Diazo-5-Oxo-l-Norleucine in Mice with Alphavirus Encephalomyelitis. J Virol 2016; 90:9251-62. [PMID: 27489275 DOI: 10.1128/jvi.01045-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/28/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Inflammation is a necessary part of the response to infection but can also cause neuronal injury in both infectious and autoimmune diseases of the central nervous system (CNS). A neurovirulent strain of Sindbis virus (NSV) causes fatal paralysis in adult C57BL/6 mice during clearance of infectious virus from the CNS, and the virus-specific immune response is implicated as a mediator of neuronal damage. Previous studies have shown that survival is improved in T-cell-deficient mice and in mice with pharmacological inhibition of the inflammatory response and glutamate excitotoxicity. Because glutamine metabolism is important in the CNS for the generation of glutamate and in the immune system for lymphocyte proliferation, we tested the effect of the glutamine antagonist DON (6-diazo-5-oxo-l-norleucine) on the outcome of NSV infection in mice. DON treatment for 7 days from the time of infection delayed the onset of paralysis and death. Protection was associated with reduced lymphocyte proliferation in the draining cervical lymph nodes, decreased leukocyte infiltration into the CNS, lower levels of inflammatory cytokines, and delayed viral clearance. In vitro studies showed that DON inhibited stimulus-induced proliferation of lymphocytes. When in vivo treatment with DON was stopped, paralytic disease developed along with the inflammatory response and viral clearance. These studies show that fatal NSV-induced encephalomyelitis is immune mediated and that antagonists of glutamine metabolism can modulate the immune response and protect against virus-induced neuroinflammatory disease. IMPORTANCE Encephalomyelitis due to infection with mosquito-borne alphaviruses is an important cause of death and of long-term neurological disability in those who survive infection. This study demonstrates the role of the virus-induced immune response in the generation of neurological disease. DON, a glutamine antagonist, inhibited the proliferation of lymphocytes in response to infection, prevented the development of brain inflammation, and protected mice from paralysis and death during treatment. However, because DON inhibited the immune response to infection, clearance of the virus from the brain was also prevented. When treatment was stopped, the immune response was generated, brain inflammation occurred, virus was cleared, and mice developed paralysis and died. Therefore, more definitive treatment for alphaviral encephalomyelitis should inhibit virus replication as well as neuroinflammatory damage.
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11
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Griffin DE. Alphavirus Encephalomyelitis: Mechanisms and Approaches to Prevention of Neuronal Damage. Neurotherapeutics 2016; 13:455-60. [PMID: 27114366 PMCID: PMC4965404 DOI: 10.1007/s13311-016-0434-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Mosquito-borne viruses are important causes of death and long-term neurologic disability due to encephalomyelitis. Studies of mice infected with the alphavirus Sindbis virus have shown that outcome is dependent on the age and genetic background of the mouse and virulence of the infecting virus. Age-dependent susceptibility reflects the acquisition by neurons of resistance to virus replication and virus-induced cell death with maturation. In mature mice, the populations of neurons most susceptible to infection are in the hippocampus and anterior horn of the spinal cord. Hippocampal infection leads to long-term memory deficits in mice that survive, while motor neuron infection can lead to paralysis and death. Neuronal death is immune-mediated, rather than a direct consequence of virus infection, and associated with entry and differentiation of pathogenic T helper 17 cells in the nervous system. To modulate glutamate excitotoxicity, mice were treated with an N-methyl-D-aspartate receptor antagonist, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonists or a glutamine antagonist. The N-methyl-D-aspartate receptor antagonist MK-801 protected hippocampal neurons but not motor neurons, and mice still became paralyzed and died. α-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor antagonists GYKI-52466 and talampanel protected both hippocampal and motor neurons and prevented paralysis and death. Glutamine antagonist 6-diazo-5-l-norleucine protected hippocampal neurons and improved memory generation in mice surviving infection with an avirulent virus. Surprisingly, in all cases protection was associated with inhibition of the antiviral immune response, reduced entry of inflammatory cells into the central nervous system, and delayed virus clearance, emphasizing the importance of treatment approaches that include prevention of immunopathologic damage.
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Affiliation(s)
- Diane E Griffin
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA.
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Athilingam P, Visovsky C, Elliott AF, Rogal PJ. Cognitive screening in persons with chronic diseases in primary care: challenges and recommendations for practice. Am J Alzheimers Dis Other Demen 2015; 30:547-58. [PMID: 25794511 PMCID: PMC10852828 DOI: 10.1177/1533317515577127] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
An integrative literature review was performed to identify the challenges in current cognitive screening. The aim of the review was to serve as an evaluative resource to guide clinicians in the selection of the best available cognitive screening measures for early assessment of mild cognitive impairment (MCI) in people with chronic diseases. The review classified the available cognitive screening measures according to purpose, time to administer, and cognitive domains assessed as: 1) simple/ brief cognitive screening measures, 2) disease specific screening measures, 3) domain specific screening measures, 4) self-administered screening measures, and 5) technology-based screening measures. There is no single optimal cognitive measure for all patient populations and settings. Although disease specific cognitive screening measures are optimal, there is a lack of validated screening measures for many chronic diseases. Technology-based screening measure is a promising avenue for increasing the accessibility of cognitive screening. Future work should focus on translating available screening measures to mobile technology format to enhance the utility in busy primary care settings. Early cognitive screening in persons with chronic disease should enhance appropriate referrals for detailed neurocognitive examination and cognitive interventions to preserve and or minimize cognitive decline.
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Melzer N, Budde T, Stork O, Meuth SG. Limbic Encephalitis: Potential Impact of Adaptive Autoimmune Inflammation on Neuronal Circuits of the Amygdala. Front Neurol 2015; 6:171. [PMID: 26284026 PMCID: PMC4522870 DOI: 10.3389/fneur.2015.00171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/20/2015] [Indexed: 12/31/2022] Open
Abstract
Limbic encephalitis is characterized by adaptive autoimmune inflammation of the gray matter structures of the limbic system. It has recently been identified as a major cause of temporal lobe epilepsy accompanied by progressive declarative – mainly episodic – memory disturbance as well as a variety of rather poorly defined emotional and behavioral changes. While autoimmune inflammation of the hippocampus is likely to be responsible for declarative memory disturbance, consequences of autoimmune inflammation of the amygdala are largely unknown. The amygdala is central for the generation of adequate homoeostatic behavioral responses to emotionally significant external stimuli following processing in a variety of parallel neuronal circuits. Here, we hypothesize that adaptive cellular and humoral autoimmunity may target and modulate distinct inhibitory or excitatory neuronal networks within the amygdala, and thereby strongly impact processing of emotional stimuli and corresponding behavioral responses. This may explain some of the rather poorly understood neuropsychiatric symptoms in limbic encephalitis.
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Affiliation(s)
- Nico Melzer
- Department of Neurology, University of Münster , Münster , Germany
| | - Thomas Budde
- Institute of Physiology I, University of Münster , Münster , Germany
| | - Oliver Stork
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg , Magdeburg , Germany
| | - Sven G Meuth
- Department of Neurology, University of Münster , Münster , Germany ; Department of Neuropathophysiology, Institute of Physiology I, University of Münster , Münster , Germany
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Ehling P, Melzer N, Budde T, Meuth SG. CD8(+) T Cell-Mediated Neuronal Dysfunction and Degeneration in Limbic Encephalitis. Front Neurol 2015; 6:163. [PMID: 26236280 PMCID: PMC4502349 DOI: 10.3389/fneur.2015.00163] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/02/2015] [Indexed: 12/31/2022] Open
Abstract
Autoimmune inflammation of the limbic gray matter structures of the human brain has recently been identified as major cause of mesial temporal lobe epilepsy with interictal temporal epileptiform activity and slowing of the electroencephalogram, progressive memory disturbances, as well as a variety of other behavioral, emotional, and cognitive changes. Magnetic resonance imaging exhibits volume and signal changes of the amygdala and hippocampus, and specific anti-neuronal antibodies binding to either intracellular or plasma membrane neuronal antigens can be detected in serum and cerebrospinal fluid. While effects of plasma cell-derived antibodies on neuronal function and integrity are increasingly becoming characterized, potentially contributing effects of T cell-mediated immune mechanisms remain poorly understood. CD8+ T cells are known to directly interact with major histocompatibility complex class I-expressing neurons in an antigen-specific manner. Here, we summarize current knowledge on how such direct CD8+ T cell–neuron interactions may impact neuronal excitability, plasticity, and integrity on a single cell and network level and provide an overview on methods to further corroborate the in vivo relevance of these mechanisms mainly obtained from in vitro studies.
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Affiliation(s)
- Petra Ehling
- Department of Neurology, Westfälische Wilhelms-University of Münster , Münster , Germany ; Institute of Physiology I - Neuropathophysiology, Westfälische Wilhelms-University , Münster , Germany
| | - Nico Melzer
- Department of Neurology, Westfälische Wilhelms-University of Münster , Münster , Germany
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-University , Münster , Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-University of Münster , Münster , Germany ; Institute of Physiology I - Neuropathophysiology, Westfälische Wilhelms-University , Münster , Germany
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Göbel K, Bittner S, Cerina M, Herrmann AM, Wiendl H, Meuth SG. An ex vivo model of an oligodendrocyte-directed T-cell attack in acute brain slices. J Vis Exp 2015. [PMID: 25741800 DOI: 10.3791/52205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Death of oligodendrocytes accompanied by destruction of neurons and axons are typical histopathological findings in cortical and subcortical grey matter lesions in inflammatory demyelinating disorders like multiple sclerosis (MS). In these disorders, mainly CD8+ T-cells of putative specificity for myelin- and oligodendrocyte-related antigens are found, so that neuronal apoptosis in grey matter lesions may be a collateral effect of these cells. Different types of animal models are established to study the underlying mechanisms of the mentioned pathophysiological processes. However, although they mimic some aspects of MS, it is impossible to dissect the exact mechanism and time course of ''collateral'' neuronal cell death. To address this course, here we show a protocol to study the mechanisms and time response of neuronal damage following an oligodendrocyte-directed CD8+ T cell attack. To target only the myelin sheath and the oligodendrocytes, in vitro activated oligodendrocyte-specific CD8+ T-cells are transferred into acutely isolated brain slices. After a defined incubation period, myelin and neuronal damage can be analysed in different regions of interest. Potential applications and limitations of this model will be discussed.
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Affiliation(s)
| | - Stefan Bittner
- Department of Neurology, University of Münster; Germany and Interdisciplinary Center for Clinical Research (IZKF) Münster
| | - Manuela Cerina
- Institute of Physiology I - Neuropathophysiology I, University of Münster
| | | | | | - Sven G Meuth
- Department of Neurology, University of Münster; Institute of Physiology I - Neuropathophysiology I, University of Münster
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Wang H, Liu S, Tang Z, Liu J. Some cross-talks between immune cells and epilepsy should not be forgotten. Neurol Sci 2014; 35:1843-9. [PMID: 25253631 DOI: 10.1007/s10072-014-1955-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 09/14/2014] [Indexed: 11/25/2022]
Abstract
Recent studies have reported that immune cells were not always found in brain specimens from epileptic patients, then should we stop investigating the relationship between these cells and epilepsy? The answer is no! In addition to immunocyte infiltration in brain parenchyma, a flurry of papers have demonstrated that there were significant alterations in peripheral blood cells (PBCs) immediately after seizure onset, especially changes in some specific transporters of neurotransmitters expressed on the membrane of immunocyte. These transporters may regulate neuronal excitability in mature neurons. Besides, many researchers did find activated leukocytes adhered to the endothelium of blood brain barrier or infiltrated into the brain parenchyma in several types of epilepsy both in human and animal studies; moreover, it is worth noting that different immune cells play different roles in epilepsy development, which was indicated by in vitro and in vivo evidence. This review is going to summarize available evidence supporting changes in PBCs after seizures, and will also focus on some specific effects of immune cells on epilepsy development.
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Affiliation(s)
- Hong Wang
- Dalian Municipal Central Hospital, No. 2 VIP Ward, Shahekou District, Dalian, 116000, Liaoning Province, China
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The neurotransmitter glutamate and human T cells: glutamate receptors and glutamate-induced direct and potent effects on normal human T cells, cancerous human leukemia and lymphoma T cells, and autoimmune human T cells. J Neural Transm (Vienna) 2014; 121:983-1006. [DOI: 10.1007/s00702-014-1167-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/19/2014] [Indexed: 12/26/2022]
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