scholarly journals Selected Clostridia Strains from The Human Microbiota and their Metabolite, Butyrate, Improve Experimental Autoimmune Encephalomyelitis

2021 ◽  
Author(s):  
Laura Calvo-Barreiro ◽  
Herena Eixarch ◽  
Thais Cornejo ◽  
Carme Costa ◽  
Mireia Castillo ◽  
...  
Keyword(s):  
Experimental Autoimmune Encephalomyelitis ◽  
Therapeutic Effect ◽  
Clinical Effect ◽  
Short Chain Fatty Acid ◽  
Human Gut ◽  
Autoimmune Encephalomyelitis ◽  
Gut Dysbiosis ◽  
Cns Autoimmunity ◽  
The Central Nervous System ◽  
Experimental Autoimmune

SummaryGut microbiome studies in multiple sclerosis (MS) patients are unravelling some consistent but modest patterns of gut dysbiosis. Among these, a significant decrease of Clostridia cluster IV and XIVa has been reported. In the present study, we investigated the therapeutic effect of a previously selected mixture of human gut-derived 17 Clostridia strains, which belong to Clostridia clusters IV, XIVa, and XVIII, on the clinical outcome of experimental autoimmune encephalomyelitis (EAE). The observed clinical improvement was related to lower demyelination and astrocyte reactivity as well as a tendency to lower microglia reactivity/infiltrating macrophages and axonal damage in the central nervous system (CNS), and to an enhanced immunoregulatory response of regulatory T cells in the periphery. Transcriptome studies also highlighted increased antiinflammatory responses related to interferon beta in the periphery and lower immune responses in the CNS. Since Clostridia-treated mice were found to present higher levels of the immunomodulatory short-chain fatty acid (SCFA) butyrate in the serum, we studied if this clinical effect could be reproduced by butyrate administration alone. Further EAE experiments proved its preventive but slight therapeutic impact on CNS autoimmunity. Thus, this smaller therapeutic effect highlighted that the Clostridia-induced clinical effect was not exclusively related to the SCFA and could not be reproduced by butyrate administration alone. Although it is still unknown if these Clostridia strains will have the same effect on MS patients, gut dysbiosis in MS patients could be partially rebalanced by these commensal bacteria and their immunoregulatory properties could have a beneficial effect on MS clinical course.

AIM2 inflammasome activation in astrocytes occurs during the late phase of EAE

2021 ◽  
Author(s):  
William E. Barclay ◽  
M. Elizabeth Deerhake ◽  
Makoto Inoue ◽  
Toshiaki Nonaka ◽  
Kengo Nozaki ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Central Nervous System ◽  
Animal Model ◽  
Cell Death ◽  
Nervous System ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Inflammasome Activation ◽  
Autoimmune Encephalomyelitis ◽  
The Central Nervous System ◽  
Experimental Autoimmune

ABSTRACTInflammasomes are a class of innate immune signaling platforms that activate in response to an array of cellular damage and pathogens. Inflammasomes promote inflammation under many circumstances to enhance immunity against pathogens and inflammatory responses through their effector cytokines, IL-1β and IL-18. Multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), are such autoimmune conditions influenced by inflammasomes. Despite work investigating inflammasomes during EAE, little remains known concerning the role of inflammasomes in the central nervous system (CNS) during the disease. Here we use multiple genetically modified mouse models to monitor activated inflammasomes in situ based on ASC oligomerization in the spinal cord. Using inflammasome reporter mice, we found heightened inflammasome activation in astrocytes after the disease peak. In contrast, microglia and CNS-infiltrated myeloid cells had few activated inflammasomes in the CNS during EAE. Astrocyte inflammasome activation was dependent on AIM2, but low IL-1β expression and no significant signs of cell death were found in astrocytes during EAE. Thus, the AIM2 inflammasome activation in astrocytes may have a distinct role from traditional inflammasome-mediated inflammation.SIGNIFICANCE STATEMENTInflammasome activation in the peripheral immune system is pathogenic in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). However, inflammasome activity in the central nervous system (CNS) is largely unexplored. Here, we used genetically modified mice to determine inflammasome activation in the CNS during EAE. Our data indicated heightened AIM2 inflammasome activation in astrocytes after the disease peak. Unexpectedly, neither CNS-infiltrated myeloid cells nor microglia were the primary cells with activated inflammasomes in SC during EAE. Despite AIM2 inflammasome activation, astrocytes did not undergo apparent cell death and produced little of the proinflammatory cytokine, IL-1β, during EAE. This study showed that CNS inflammasome activation occurs during EAE without associating with IL-1β-mediated inflammation.

scholarly journals Vaccination with DNA Encoding an Immunodominant Myelin Basic Protein Peptide Targeted to Fc of Immunoglobulin G Suppresses Experimental Autoimmune Encephalomyelitis

1998 ◽  
Vol 187 (9) ◽  
pp. 1543-1548 ◽  
Author(s):  
Anna Lobell ◽  
Robert Weissert ◽  
Maria K. Storch ◽  
Cecilia Svanholm ◽  
Katrien L. de Graaf ◽  
...  
Keyword(s):  
Autoimmune Disease ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Cell Epitope ◽  
Interferon Γ ◽  
Dna Encoding ◽  
Autoimmune Encephalomyelitis ◽  
The Central Nervous System ◽  
Experimental Autoimmune

We explore here if vaccination with DNA encoding an autoantigenic peptide can suppress autoimmune disease. For this purpose we used experimental autoimmune encephalomyelitis (EAE), which is an autoaggressive disease in the central nervous system and an animal model for multiple sclerosis. Lewis rats were vaccinated with DNA encoding an encephalitogenic T cell epitope, guinea pig myelin basic protein peptide 68–85 (MBP68–85), before induction of EAE with MBP68–85 in complete Freund's adjuvant. Compared to vaccination with a control DNA construct, the vaccination suppressed clinical and histopathological signs of EAE, and reduced the interferon γ production after challenge with MBP68–85. Targeting of the gene product to Fc of IgG was essential for this effect. There were no signs of a Th2 cytokine bias. Our data suggest that DNA vaccines encoding autoantigenic peptides may be useful tools in controlling autoimmune disease.

scholarly journals Dectin-1 limits central nervous system autoimmunity through a non-canonical pathway

2020 ◽  
Author(s):  
M. Elizabeth Deerhake ◽  
Keiko Danzaki ◽  
Makoto Inoue ◽  
Emre D. Cardakli ◽  
Toshiaki Nonaka ◽  
...  
Keyword(s):  
Experimental Autoimmune Encephalomyelitis ◽  
Myeloid Cells ◽  
Oncostatin M ◽  
List Type ◽  
Autoimmune Encephalomyelitis ◽  
Protective Function ◽  
Lectin Receptor ◽  
Neurologic Disorders ◽  
Cns Autoimmunity ◽  
Experimental Autoimmune

ABSTRACTPathologic roles for innate immunity in neurologic disorders are well-described, but protective aspects of the immune response are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely known to induce inflammation. However, we found that Dectin-1 is protective in experimental autoimmune encephalomyelitis (EAE), while its canonical signaling mediator, Card9, promotes the disease. Notably, Dectin-1 does not respond to heat-killed Mycobacteria, an adjuvant to induce EAE. Myeloid cells mediate the protective function of Dectin-1 in EAE and upregulate gene expression of neuroprotective molecules, including Oncostatin M (Osm) through a non-canonical Card9-independent pathway, mediated by NFAT. Furthermore, we found that the Osm receptor (OsmR) functions specifically in astrocytes to reduce EAE severity. Our study revealed a new mechanism of protective myeloid-astrocyte crosstalk regulated by a non-canonical Dectin-1 pathway and identifies novel therapeutic targets for CNS autoimmunity.Graphical AbstractDectin-1 is a protective C-type lectin receptor (CLR) in experimental autoimmune encephalomyelitis (EAE)Dectin-1 promotes expression of Osm, a neuroprotective IL-6 family cytokine, in myeloid cellsOsmR signaling in astrocytes limits EAE progression and promotes remissionNon-canonical Card9-independent signaling drives a distinct Dectin-1-mediated transcriptional program to induce expression of Osm and other factors with protective or anti-inflammatory functions

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