Search results for "Encephalomyelitis"

A T cell-specific deletion of HDAC1 protects against experimental autoimmune encephalomyelitis.

2017

Multiple sclerosis (MS) is a human neurodegenerative disease characterized by the invasion of autoreactive T cells from the periphery into the CNS. Application of pan-histone deacetylase inhibitors (HDACi) ameliorates experimental autoimmune encephalomyelitis (EAE), an animal model for MS, suggesting that HDACi might be a potential therapeutic strategy for MS. However, the function of individual HDAC members in the pathogenesis of EAE is not known. In this study we report that mice with a T cell-specific deletion of HDAC1 (using the Cd4-Cre deleter strain; HDAC1-cKO) were completely resistant to EAE despite the ability of HDAC1cKO CD4+ T cells to differentiate into Th17 cells. RNA sequencin…

Nutritional control of IL-23/Th17-mediated autoimmune disease through HO-1/STAT3 activation

2017

AbstractThe nutritional curcumin (CUR) is beneficial in cell-mediated autoimmune diseases. The molecular mechanisms underlying this food-mediated silencing of inflammatory immune responses are poorly understood. By investigating antigen-specific immune responses we found that dietary CUR impairs the differentiation of Th1/Th17 cells in vivo during encephalomyelitis and instead promoted Th2 cells. In contrast, feeding CUR had no inhibitory effect on ovalbumin-induced airway inflammation. Mechanistically, we found that CUR induces an anti-inflammatory phenotype in dendritic cells (DC) with enhanced STAT3 phosphorylation and suppressed expression of Il12b and Il23a. On the molecular level CUR …

Dimethyl fumarate alters intracellular Ca2+ handling in immune cells by redox-mediated pleiotropic effects

2019

Dimethyl fumarate (DMF) is widely used to treat the human autoimmune diseases multiple sclerosis (MS) and psoriasis. DMF causes short-term oxidative stress and activates the antioxidant response via the transcription factor Nrf2 but its immunosuppressive effect is not well understood. Immune cell activation depends on calcium signaling which itself is influenced by the cellular redox state. We therefore measured calcium, reactive oxygen species levels and glutathione content in lymphocytes from immunized mice before onset of experimental autoimmune encephalomyelitis, in peripheral blood mononuclear cells from MS patients treated with DMF, and in mouse splenocytes treated ex vivo with DMF. T…

RNase H2 Loss in Murine Astrocytes Results in Cellular Defects Reminiscent of Nucleic Acid-Mediated Autoinflammation

2018

Aicardi-Goutières syndrome (AGS) is a rare early onset childhood encephalopathy caused by persistent neuroinflammation of autoimmune origin. AGS is a genetic disorder and >50% of affected individuals bear hypomorphic mutations in ribonuclease H2 (RNase H2). All available RNase H2 mouse models so far fail to mimic the prominent CNS involvement seen in AGS. To establish a mouse model recapitulating the human disease, we deleted RNase H2 specifically in the brain, the most severely affected organ in AGS. Although RNase H2δGFAPmice lacked the nuclease in astrocytes and a majority of neurons, no disease signs were apparent in these animals. We additionally confirmed these results…

Peripherally Induced Regulatory T Cells: Recruited Protectors of the Central Nervous System against Autoimmune Neuroinflammation

2017

Defects in regulatory T cells (Treg cells) aggravate multiple sclerosis (MS) after its onset and the absence of Treg cell functions can also exacerbate the course of disease in an animal model of MS. However, autoimmune neuroinflammation in many MS models can be acutely provoked in healthy animals leading to an activation of encephalitogenic T cells despite the normal induction of immune tolerance in the thymus including thymically-produced (t)Treg cells. In contrast, neuroinflammation can be ameliorated or even completely prevented by the antigen-specific Treg cells formed extrathymically in the peripheral immune system (pTreg cells) during tolerogenic responses to relevant neuronal antige…

2020

The brain ventricles are part of the fluid compartments bridging the CNS with the periphery. Using MRI, we previously observed a pronounced increase in ventricle volume (VV) in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). Here, we examined VV changes in EAE and MS patients in longitudinal studies with frequent serial MRI scans. EAE mice underwent serial MRI for up to 2 months, with gadolinium contrast as a proxy of inflammation, confirmed by histopathology. We performed a time-series analysis of clinical and MRI data from a prior clinical trial in which RRMS patients underwent monthly MRI scans over 1 year. VV increased dramatically during preonset E…

Cellular mechanisms of IL-17-induced blood-brain barrier disruption.

2009

Recently T-helper 17 (Th17) cells were demonstrated to disrupt the blood-brain barrier (BBB) by the action of IL-17A. The aim of the present study was to examine the mechanisms that underlie IL-17A-induced BBB breakdown. Barrier integrity was analyzed in the murine brain endothelial cell line bEnd.3 by measuring the electrical resistance values using electrical call impedance sensing technology. Furthermore, in-cell Western blots, fluorescence imaging, and monocyte adhesion and transendothelial migration assays were performed. Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 mice. IL-17A induced NADPH oxidase- or xanthine oxidase-dependent reactive oxygen species (ROS)…

Genetic proof for the transient nature of the Th17 phenotype

2010

IL-17-producing CD4(+) T cells (Th17) have been classified as a new T helper cell subset. Using an IL-17 fate mapping mouse strain, which genetically fixes the memory of IL-17 expression, we demonstrate that IL-17A/F-expressing T helper cells generated either in vitro or in vivo are not a stable T-cell subset. Upon adoptive transfer of IL-17F-reporter-positive Th17 cells to RAG-deficient or WT animals, encephalitogenic Th17 cells partially lose IL-17 expression and upregulate IFN-γ. Additionally, we show that Th1 cells can convert in vivo to IL-17A/IFN-γ-coexpressing cells in the mesenteric lymph nodes (mLN). Our data classify IL-17A and IL-17F as cytokines produced transiently in response …

Lack of requirement for CD8+ cells in recovery from and resistance to experimental autoimmune encephalomyelitis.

1995

Abstract Experimental autoimmune encephalomyelitis (EAE) is a model of T-cell mediated autoimmune disease. Active disease is mediated by myelin basic protein specific CD4+T-cells, whose adoptive transfer can also induce passive disease. In the Lewis rat EAE is a transient disease inducing lasting resistance to rechallenge. The mechanisms of recovery and resistance are poorly understood. CD8+suppressor T-cells have mostly been thought to be central, especially in resistance to reinduction of the disease. In this study we showed by complete depletion of CD8+cells that this subset does not influence either recovery or resistance to EAE in the Lewis rat. This was further confirmed by depleting …

2014

Introduction We and others recently showed that IL-17-producing Th17 cells are highly unstable in their phenotype and swiftly upregulate T-bet and Th1-associated cytokines in the inflamed CNS of mice with EAE [1] . This inherent plasticity was recently associated with IL-23, IFN-γ or IL-12 signalling on effector T cells [2] , [3] . Aim To understand the role of IFN-γ and IL-27 signaling for plasticity of Th17 cells in vivo. Methods We use mice lacking the IFN-γ receptor 2 chain specifically in T cells (CD4cre × IFNγR2FL/FL) as well as blocking antibodies for IFN-γ and IL-27-p28 and knockout mice for IL-27-EBI3. Further we use IL-17 reporter mice to sort Th17 cells prior adoptive transfer. W…