Targeting CNS myeloid infiltrates provides neuroprotection in a progressive multiple sclerosis model.

Demyelination and axonal injury in chronic-progressive Multiple Sclerosis (MS) are presumed to be driven by a neurotoxic bystander effect of meningeal-based myeloid infiltrates. There is an unmet clinical need to attenuate disease progression in such forms of CNS-compartmentalized MS. The failure of systemic immune suppressive treatments has highlighted the need for neuroprotective and repair-inducing strategies. Here, we examined whether direct targeting of CNS myeloid cells and modulating their toxicity may prevent irreversible tissue injury in chronic immune-mediated demyelinating disease. To that end, we utilized the experimental autoimmune encephalomyelitis (EAE) model in Biozzi mice, a clinically relevant MS model. We continuously delivered intracerebroventricularly (ICV) a retinoic acid receptor alpha agonist (RARα), as a potent regulator of myeloid cells, in the chronic phase of EAE. We assessed disease severity and performed pathological evaluations, functional analyses of immune cells, and single-cell RNA sequencing on isolated spinal CD11b+ cells. Although initiating treatment in the chronic phase of the disease, the RARα agonist successfully improved clinical outcomes and prevented axonal loss. ICV RARα agonist treatment inhibited pro-inflammatory pathways and shifted CNS myeloid cells toward neuroprotective phenotypes without affecting peripheral infiltrating myeloid cell phenotypes, or peripheral immunity. The treatment regulated cell-death pathways across multiple myeloid cell populations and suppressed apoptosis, resulting in paradoxically marked increased neuroinflammatory infiltrates, consisting mainly of microglia and CNS / border-associated macrophages. This work establishes the notion of bystander neurotoxicity by CNS immune infiltrates in chronic demyelinating disease. Furthermore, it shows that targeting compartmentalized neuroinflammation by selective regulation of CNS myeloid cell toxicity and survival reduces irreversible tissue injury, and may serve as a novel disease-modifying approach.

atRA Attenuates High Salt-Driven EAE Mainly Through Suppressing Th17-Like Regulatory T Cell Response Mediated by the Inhibition of IL-23R Signaling Pathway.

High salt diet (HSD) is implicated in numerous disorders, which boosts Th17 cell development and weakens immunosuppressive function of regulatory T cells (Treg cells) Treg cells, leading to the exacerbation of EAE. However, little is known regarding the harness of excessive proinflammatory responses evoked by HSD. Here we show that atRA, a key vitamin A metabolite with multifaceted immunoregulatory properties has the potential in inhibiting the proinflammatory reaction of high salt. Treatment with atRA in vivo elicited the Treg generation in cervical and axillary lymph nodes (CALs), and in CNS of experimental autoimmune encephalomyelitis (EAE). Meanwhile, the proportion of Th17-like Treg cells (RORγt-positive or GM-CSF-positive Treg cells) decreased in CALs. atRA also inhibited IL-17A expression in CD4+ effector T cells. In-vitro mechanistic studies showed that atRA inhibit IL-23R but not SGK1 expression in Treg cells and this results in maintained immunosuppressive function of Treg cells even in the presence of IL-6 and high salt. Furthermore, treatment of EAE with anti-IL-23R mAb attenuated HSD-provoked EAE progress. This was associated with a reduction in the number of CNS-infiltrating Th17 cells and an increase of CAL-Treg cells. Mechanically, treatment with atRA significantly promoted LP-CD103+CD11c+ dendritic cells, a subgroup of cells most closely involved in endogenous retinoic acid metabolism, and enhanced intestinal Aldh1a1 and Rdh10 expression from HSD-fed EAE mice. Interestingly, anti-IL-23R mAb administration also reduced IL-23R expression in Treg cells, along with the increased proportion of LP-CD103+CD11c+ dendritic cells and Rdh10 mRNA expression. In conclusion, administration of atRA might be a way to combat the proinflammatory effects of HSD. Meanwhile, systematic inhibition of IL-23R also had a moderate therapeutic potential in inhibiting inflammatory effects of high salt, which may serve as a basis for the identification of novel therapeutic strategies against HSD-driven autoimmune disorders.

Interleukin-10 contrasts inflammatory synaptopathy and central neurodegenerative damage in multiple sclerosis.

Proinflammatory cytokines are implicated in promoting neurodegeneration in multiple sclerosis (MS) by affecting excitatory and inhibitory transmission at central synapses. Conversely, the synaptic effects of anti-inflammatory molecules remain underexplored, despite their potential neuroprotective properties and their presence in the cerebrospinal fluid (CSF) of patients. In a study involving 184 newly diagnosed relapsing-remitting (RR)-MS patients, we investigated whether CSF levels of the anti-inflammatory interleukin (IL)-10 were linked to disease severity and neurodegeneration measures. Additionally, we examined IL-10 impact on synaptic transmission in striatal medium spiny neurons and its role in counteracting inflammatory synaptopathy induced by IL-1ß in female C57BL/6 mice with experimental autoimmune encephalomyelitis (EAE). Our findings revealed a significant positive correlation between IL-10 CSF levels and changes in EDSS (Expanded Disability Status Scale) scores one year after MS diagnosis. Moreover, IL-10 levels in the CSF were positively correlated with volumes of specific subcortical brain structures, such as the nucleus caudate. In both MS patients' CSF and EAE mice striatum, IL-10 and IL-1ß expressions were upregulated, suggesting possible antagonistic effects of these cytokines. Notably, IL-10 exhibited the ability to decrease glutamate transmission, increase GABA transmission in the striatum, and reverse IL-1ß-induced abnormal synaptic transmission in EAE. In conclusion, our data suggest that IL-10 exerts direct neuroprotective effects in MS patients by modulating both excitatory and inhibitory transmission and attenuating IL-1ß-induced inflammatory synaptopathy. These findings underscore the potential therapeutic significance of IL-10 in mitigating neurodegeneration in MS.

The Antidepressant- and Anxiolytic-Like Effects of the Phosphodiesterase Type-5 Inhibitor Tadalafil are Associated with the Modulation of the Gut-Brain Axis During CNS Autoimmunity.

Multiple Sclerosis (MS) is a debilitating disease that severely affects the central nervous system (CNS). Apart from neurological symptoms, it is also characterized by neuropsychiatric comorbidities, such as anxiety and depression. Phosphodiesterase-5 inhibitors (PDE5Is) such as Sildenafil and Tadalafil have been shown to possess antidepressant-like effects, but the mechanisms underpinning such effects are not fully characterized. To address this question, we used the EAE model of MS, behavioral tests, immunofluorescence, immunohistochemistry, western blot, and 16 S rRNA sequencing. Here, we showed that depressive-like behavior in Experimental Autoimmune Encephalomyelitis (EAE) mice is due to neuroinflammation, reduced synaptic plasticity, dysfunction in glutamatergic neurotransmission, glucocorticoid receptor (GR) resistance, increased blood-brain barrier (BBB) permeability, and immune cell infiltration to the CNS, as well as inflammation, increased intestinal permeability, and immune cell infiltration in the distal colon. Furthermore, 16 S rRNA sequencing revealed that behavioral dysfunction in EAE mice is associated with changes in the gut microbiota, such as an increased abundance of Firmicutes and Saccharibacteria and a reduction in Proteobacteria, Parabacteroides, and Desulfovibrio. Moreover, we detected an increased abundance of Erysipelotrichaceae and Desulfovibrionaceae and a reduced abundance of Lactobacillus johnsonii. Surprisingly, we showed that Tadalafil likely exerts antidepressant-like effects by targeting all aforementioned disease aspects. In conclusion, our work demonstrated that anxiety- and depressive-like behavior in EAE is associated with a plethora of neuroimmune and gut microbiota-mediated mechanisms and that Tadalafil exerts antidepressant-like effects probably by targeting these mechanisms. Harnessing the knowledge of these mechanisms of action of Tadalafil is important to pave the way for future clinical trials with depressed patients.

Dosage and organic acid residue of MOG35-55 peptide influences immunopathology and development of BCG induced experimental autoimmune encephalomyelitis (EAE).

Experimental autoimmune encephalomyelitis (EAE) serves as a model for studying multiple sclerosis, with immunization strategies utilizing MOG35-55 peptide, emulsified in adjuvant enriched with mycobacterium tuberculosis (Mtb). This study examined the effects of Bacillus Calmette-Guérin (BCG) as an adjuvant, alongside the impact of MOG35-55 peptide doses and their residual counter ions on EAE development. We found that BCG can be effectively used to induce EAE with similar incidence and severity as heat-killed H37Ra, contingent upon the appropriate MOG35-55 peptide dose. Different immunization doses of MOG35-55 peptide significantly affect EAE development, with higher doses leading to a paradoxical reduction in disease activity, probably due to peripheral tolerance mechanisms. Furthermore, doses of MOG35-55 peptides with acetate showed a more pronounced effect on disease development compared to those containing trifluoroacetic acid (TFA), suggesting the potential influence of residual counter ions on EAE activity. We highlighted the feasibility of applying BCG to the establishment of EAE for the first time. Our findings emphasized the importance of MOG peptide dosage and composition in modulating EAE development, offering insights into the mechanisms of autoimmunity and tolerance. This could have implications for autoimmune disease research and the design of therapeutic strategies.

Methylprednisolone Modulates the Tfr/Tfh ratio in EAE-Induced Neuroinflammation through the PI3K/AKT/FoxO1 and PI3K/AKT/mTOR Signalling Pathways.

Methylprednisolone (MP) is a potent glucocorticoid that can effectively inhibit immune system inflammation and brain tissue damage in Multiple sclerosis (MS) patients. T follicular helper (Tfh) cells are a subpopulation of activated CD4 + T cells, while T follicular regulatory (Tfr) cells, a novel subset of Treg cells, possess specialized abilities to suppress the Tfh-GC response and inhibit antibody production. Dysregulation of either Tfh or Tfr cells has been implicated in the pathogenesis of MS. However, the molecular mechanism underlying the anti-inflammatory effects of MP therapy on experimental autoimmune encephalomyelitis (EAE), a representative model for MS, remains unclear. This study aimed to investigate the effects of MP treatment on EAE and elucidate the possible underlying molecular mechanisms involed. We evaluated the effects of MP on disease progression, CNS inflammatory cell infiltration and myelination, microglia and astrocyte activation, as well as Tfr/Tfh ratio and related molecules/inflammatory factors in EAE mice. Additionally, Western blotting was used to assess the expression of proteins associated with the PI3K/AKT pathway. Our findings demonstrated that MP treatment ameliorated clinical symptoms, inflammatory cell infiltration, and myelination. Furthermore, it reduced microglial and astrocytic activation. MP may increase the number of Tfr cells and the levels of cytokine TGF-ß1, while reducing the number of Tfh cells and the levels of cytokine IL-21, as well as regulate the imbalanced Tfr/Tfh ratio in EAE mice. The PI3K/AKT/FoxO1 and PI3K/AKT/mTOR pathways were found to be involved in EAE development. However, MP treatment inhibited their activation. MP reduced neuroinflammation in EAE by regulating the balance between Tfr/Tfh cells via inhibition of the PI3K/AKT/FoxO1 and PI3K/AKT/mTOR signalling pathways.

Amniotic fluid stem cell-derived extracellular vesicles educate type 2 conventional dendritic cells to rescue autoimmune disorders in a multiple sclerosis mouse model.

Dendritic cells (DCs) are essential orchestrators of immune responses and represent potential targets for immunomodulation in autoimmune diseases. Human amniotic fluid secretome is abundant in immunoregulatory factors, with extracellular vesicles (EVs) being a significant component. However, the impact of these EVs on dendritic cells subsets remain unexplored. In this study, we investigated the interaction between highly purified dendritic cell subsets and EVs derived from amniotic fluid stem cell lines (HAFSC-EVs). Our results suggest that HAFSC-EVs are preferentially taken up by conventional dendritic cell type 2 (cDC2) through CD29 receptor-mediated internalization, resulting in a tolerogenic DC phenotype characterized by reduced expression and production of pro-inflammatory mediators. Furthermore, treatment of cDC2 cells with HAFSC-EVs in coculture systems resulted in a higher proportion of T cells expressing the regulatory T cell marker Foxp3 compared to vehicle-treated control cells. Moreover, transfer of HAFSC-EV-treated cDC2s into an EAE mouse model resulted in the suppression of autoimmune responses and clinical improvement. These results suggest that HAFSC-EVs may serve as a promising tool for reprogramming inflammatory cDC2s towards a tolerogenic phenotype and for controlling autoimmune responses in the central nervous system, representing a potential platform for the study of the effects of EVs in DC subsets.

Pin1 maintains the effector program of pathogenic Th17 cells in autoimmune neuroinflammation.

Th17 cells mediated immune response is the basis of a variety of autoimmune diseases, including multiple sclerosis and its mouse model of immune aspects, experimental autoimmune encephalomyelitis (EAE). The gene network that drives both the development of Th17 and the expression of its effector program is dependent on the transcription factor RORγt. In this report, we showed that Peptidylprolyl Cis/Trans Isomerase, NIMA-Interacting 1 (Pin1) formed a complex with RORγt, and enhanced its transactivation activity, thus sustained the expression of the effector genes as well as RORγt in the EAE-pathogenic Th17 cells. We first found out that PIN1 was highly expressed in the samples from patients of multiple sclerosis, and the expression of Pin1 by the infiltrating lymphocytes in the central nerve system of EAE mice was elevated as well. An array of experiments with transgenic mouse models, cellular and molecular assays was included in the study to elucidate the role of Pin1 in the pathology of EAE. It turned out that Pin1 promoted the activation and maintained the effector program of EAE-pathogenic Th17 cells in the inflammation foci, but had little effect on the priming of Th17 cells in the draining lymph nodes. Mechanistically, Pin1 stabilized the phosphorylation of STAT3 induced by proinflammatory stimuli, and interacted with STAT3 in the nucleus of Th17 cells, which resulted in the increased expression of Rorc. Moreover, Pin1 formed a complex with RORγt, and enhanced the transactivation of RORγt to the +11 kb enhancer of Rorc, which enforced and maintained the expression of both Rorc and the effector program of pathogenic Th17 cells in EAE. Finally, the inhibition of Pin1, by genetic knockdown or by small molecule inhibitor, deceased the population of Th17 cells and the neuroinflammation, and alleviated the symptoms of EAE. These findings suggest that Pin1 is a potential therapeutic target for MS and other autoimmune inflammatory diseases.

Autoantibodies-Abzymes with Phosphatase Activity in Experimental Autoimmune Encephalomyelitis Mice.

The exact mechanisms of MS (multiple sclerosis) evolution are still unknown. However, the development of EAE (experimental autoimmune encephalomyelitis simulating human MS) in C57BL/6 mice occurs due to the violation of bone marrow hematopoietic stem cell differentiation profiles, leading to the production of toxic for human autoantibody splitting MBP (myelin basic protein), MOG (mouse oligodendrocyte glycoprotein), five histones, DNA, and RNA. Here, we first analyzed the changes in the relative phosphatase activity of IgGs from C57BL/6 mice blood over time, corresponding to three stages of EAE: onset, acute, and remission. Antibodies have been shown to catalyze the hydrolysis of p-nitrophenyl phosphate at several optimal pH values, mainly in the range of 6.5-7.0 and 8.5-9.5. During the spontaneous development of EAE, the most optimal value is pH 6.5. At 50 days after the birth of mice, the phosphatase activity of IgGs at pH 8.8 is 1.6-fold higher than at pH 6.5. During spontaneous development of EAE from 50 to 100 days, an increase in phosphatase activity is observed at pH 6.5 but a decrease at pH 8.8. After mice were immunized with DNA-histone complex by 20 and 60 days, phosphatase activity increased respectively by 65.3 and 109.5 fold (pH 6.5) and 128.4 and 233.6 fold (pH 8.8). Treatment of mice with MOG at the acute phase of EAE development (20 days) leads to a maximal increase in the phosphatase activity of 117.6 fold (pH 6.5) and 494.7 fold (pH 8.8). The acceleration of EAE development after mice treatment with MOG and DNA-histone complex results in increased production of lymphocytes synthesizing antibodies with phosphatase activity. All data show that IgG phosphatase activity could be essential in EAE pathogenesis.

Chronic Inflammation Disrupts Circadian Rhythms in Splenic CD4+ and CD8+ T Cells in Mice.

Internal circadian clocks coordinate 24 h rhythms in behavior and physiology. Many immune functions show daily oscillations, and cellular circadian clocks can impact immune functions and disease outcome. Inflammation may disrupt circadian clocks in peripheral tissues and innate immune cells. However, it remains elusive if chronic inflammation impacts adaptive immune cell clock, e.g., in CD4+ and CD8+ T lymphocytes. We studied this in the experimental autoimmune encephalomyelitis (EAE), a mouse model for multiple sclerosis, as an established experimental paradigm for chronic inflammation. We analyzed splenic T cell circadian clock and immune gene expression rhythms in mice with late-stage EAE, CFA/PTx-treated, and untreated mice. In both treatment groups, clock gene expression rhythms were altered with differential effects for baseline expression and peak phase compared with control mice. Most immune cell marker genes tested in this study did not show circadian oscillations in either of the three groups, but time-of-day- independent alterations were observed in EAE and CFA/PTx compared to control mice. Notably, T cell effects were likely independent of central clock function as circadian behavioral rhythms in EAE mice remained intact. Together, chronic inflammation induced by CFA/PTx treatment and EAE immunization has lasting effects on circadian rhythms in peripheral immune cells.

Tumor necrosis factor receptor 2 activation elicits sex-specific effects on cortical myelin proteins and functional recovery in a model of multiple sclerosis.

Multiple sclerosis (MS), a demyelinating autoimmune disease of the central nervous system (CNS), predominately affects females compared to males. Tumor necrosis factor (TNF), a pro-inflammatory cytokine, signaling through TNF receptor 1 contributes to inflammatory disease pathogenesis. In contrast, TNF receptor 2 signaling is neuroprotective. Current anti-TNF MS therapies are shown to be detrimental to patients due to pleiotropic effects on both pro- and anti-inflammatory functions. Using a non-pertussis toxin (nPTX) experimental autoimmune encephalomyelitis (EAE) model in C57BL/6 mice, we systemically administered a TNFR2 agonist (p53-sc-mTNFR2) to investigate behavioral and pathophysiological changes in both female and male mice. Our data shows that TNFR2 activation alleviates motor and sensory symptoms in females. However, in males, the agonist only alleviates sensory symptoms and not motor. nPTX EAE induction in TNFR2 global knockout mice caused exacerbated motor symptoms in females along with an earlier day of onset, but not in males. Our data demonstrates that TNFR2 agonist efficacy is sex-specific for alleviation of motor symptoms, however, it effectively reduces mechanical hypersensitivity in both females and males. Altogether, these data support the therapeutic promise TNFR2 agonism holds as an MS therapeutic and, more broadly, to treat central neuropathic pain.

Active Induction of a Multiple Sclerosis-Like Disease in Common Laboratory Mouse Strains.

Experimental autoimmune encephalomyelitis (EAE) is a neuroinflammatory disease with facets in common with multiple sclerosis (MS). It is induced in susceptible mammalian species, with rodents as the preferred hosts, and has been used for decades as a model to investigate the immunopathogenesis of MS as well as for preclinical evaluation of candidate MS therapeutics. Most commonly, EAE is generated by active immunization with central nervous system (CNS) antigens, such as whole CNS homogenate, myelin proteins, or peptides derived from these proteins. However, EAE actually represents a spectrum of diseases in which specific combinations of host/CNS antigen exhibit defined clinical profiles, each associated with unique immunological and pathological features. Similar to MS, EAE is a complex disease where development and progression are also modulated by environmental factors; therefore, the establishment of any given EAE variant can be challenging and requires careful optimization. Here, we describe protocols for three EAE variants, successfully generated in our laboratory, and provide additional information as to how to maintain their unique features and reproducibility.

ROS-Scavenging Lignin-Based Tolerogenic Nanoparticle Vaccine for Treatment of Multiple Sclerosis.

Multiple sclerosis (MS) is a demyelinating autoimmune disease, in which the immune system attacks myelin. Although systemic immunosuppressive agents have been used to treat MS, long-term treatment with these drugs causes undesirable side effects such as altered glucose metabolism, insomnia, and hypertension. Herein, we propose a tolerogenic therapeutic vaccine to treat MS based on lignin nanoparticles (LNP) with intrinsic reactive oxygen species (ROS)-scavenging capacity derived from their phenolic moieties. The LNP loaded with autoantigens of MS allowed for inducing tolerogenic DCs with low-level expression of costimulatory molecules while presenting antigenic peptides. Intravenous injection of an LNP-based tolerogenic vaccine into an experimental autoimmune encephalomyelitis (EAE) model led to durable antigen-specific immune tolerance via inducing regulatory T cells (Tregs). Autoreactive T helper type 1 cells, T helper type 17 cells, and inflammatory antigen presentation cells (APCs) were suppressed in the central nervous system (CNS), ameliorating ongoing MS in early and late disease states. Additionally, the incorporation of dexamethasone into an LNP-based tolerogenic nanovaccine could further improve the recovery of EAE mice in the severe chronic stage. As lignin is the most abundant biomass and waste byproduct in the pulping industry, a lignin-based tolerogenic vaccine could be a novel, cost-effective, high-value vaccine platform with potent therapeutic efficiency in treating autoimmune diseases.

Novel liposomal glatiramer acetate: Preparation and immunomodulatory evaluation in murine model of multiple sclerosis.

The frequent administration rate required for Glatiramer acetate (GA), a first-line therapy for Multiple sclerosis (MS), poses patient compliance issues. Only a small portion of the subcutaneously administered GA is available for phagocytosis by macrophages, as most of it is hydrolyzed at its administration site or excreted renally. To unravel these hurdles, we have prepared liposomal formulations of GA through thin film-hydration method plus extrusion. The clinical and histopathological efficacy of GA-loaded liposomes were assessed in prophylactic and therapeutic manners on murine model of MS (experimental autoimmune encephalomyelitis (EAE)). The selected GA liposomal formulation showed favorable size (275 nm on average), high loading efficiency, and high macrophage localization. Moreover, administration of GA-liposomes in mice robustly suppressed the inflammatory responses and decreased the inflammatory and demyelinated lesion regions in CNS compared to the free GA with subsequent reduction of the EAE clinical score. Our study indicated that liposomal GA could be served as a reliable nanomedicine-based platform to hopefully curb MS-related aberrant autoreactive immune responses with higher efficacy, longer duration of action, fewer administration frequencies, and higher delivery rate to macrophages. This platform has the potential to be introduced as a vaccine for MS after clinical translation and merits further investigations.

Early life stress aggravates disease pathogenesis in mice with experimental autoimmune encephalomyelitis: Support for a two-hit hypothesis of multiple sclerosis etiology.

Vision problems are one of the earliest diagnosed symptoms of multiple sclerosis (MS). The onset and progression of vision loss and the underlying pathogenesis in MS may be influenced by cumulative psychophysiological stress. Here, we used a two-hit model of stress in female mice to determine if early life stress (ELS, the first hit) influences the response to an immunization that induces experimental autoimmune encephalomyelitis (EAE, the second hit) later in life. We hypothesized that ELS caused by animal transportation from a vendor during early postnatal development represents a co-factor which can exacerbate the clinical severity of EAE. Indeed, adult EAE mice with a history of ELS displayed more severe clinical signs and delayed recovery compared to non-stressed EAE mice. ELS also diminished visual acuity measured by optokinetic responses, as well as locomotion and exploratory behaviours in EAE mice. Notably, ELS accelerated vision loss and caused earlier onset of visual impairments in EAE. Exacerbated functional impairments in stressed EAE mice were highly correlated with circulating corticosterone levels. The findings show that the progression of induced EAE in adulthood can be significantly impacted by adverse early life experiences. These observations emphasize the importance of comprehensive behavioural testing, including non-motor functions, to enhance the translational value of preclinical animal models of MS. Moreover, shipment stress of laboratory animals should be considered a necessary variable in preclinical MS research. The consideration of cumulative lifetime stresses provides a new perspective of MS pathogenesis within a personalized medicine framework.

Engineering chimeric autoantibody receptor T cells for targeted B cell depletion in multiple sclerosis model: An in-vitro study.

Background: Recent evidence suggests that B cells and autoantibodies have a substantial role in the pathogenesis of Multiple sclerosis. T cells could be engineered to express chimeric autoantibody receptors (CAARs), which have an epitope of autoantigens in their extracellular domain acting as bait for trapping autoreactive B cells. This study aims to assess the function of designed CAAR T cells against B cell clones reactive to the myelin basic protein (MBP) autoantigen. Methods: T cells were transduced to express a CAAR consisting of MBP as the extracellular domain. experimental autoimmune encephalomyelitis (EAE) was induced by injecting MBP into mice. The cytotoxicity, proliferation, and cytokine production of the MBP-CAAR T cells were investigated in co-culture with B cells. Results: MBP-CAAR T cells showed higher cytotoxic activity against autoreactive B cells in all effector-to-target ratios compared to Mock T cell (empty vector-transduced T cell) and Un-T cells (un-transduced T cell). In co-cultures containing CAAR T cells, there was more proliferation and inflammatory cytokine release as compared to Un-T and Mock T cell groups. Conclusion: Based on these findings, CAAR T cells are promising for curing or modulating autoimmunity and can be served as a new approach for clone-specific B cell depletion therapy in multiple sclerosis.

Astragaloside IV inhibits experimental autoimmune encephalomyelitis by modulating the polarization of both microglia/macrophages and astrocytes.

Astragaloside IV (AST IV), a major saponin component and active ingredient isolated from Astragalus membranaceus, has been well known to exhibit neuroprotective effects on diverse models of neurological diseases. Accumulating evidence suggests that dynamic balance of microglia/macrophages and astrocytes plays a vital role in neuroprotection and remyelination. However, dysregulation of microglia/macrophages and astrocytes orchestrate the pathogenesis of nervous system disorders. Therefore, we hypothesized that switching the transformation of microglia/macrophages and astrocytes into the neuroprotective M2 and A2 phenotypes, respectively, could be a potential target for therapeutic intervention. In the present study, we evaluate the efficacy of AST IV intervention on the effects of microglia/macrophages and astrocytes in an experimental autoimmune encephalomyelitis (EAE) model. AST IV improved paralysis and pathology of EAE by inhibiting the neurotoxic M1 microglia/macrophage phenotype, promoting M2 phenotype, shifting astrocytes towards a neuroprotective A2 phenotype, and protecting neurons from apoptosis through inhibition of TLR4/Myd88/NF-kB signalling pathway. Our study showed that AST IV could be a potential and promising drug for multiple sclerosis treatment.

The impact of ketogenic diet on the onset and progression of multiple sclerosis.

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by inflammation and neurodegeneration. Current research suggests that diet may influence disease course, severity of symptoms, and quality of life in MS patients. The ketogenic diet (KD) has been used for more than a century as a therapeutic approach for various medical conditions. It was originally developed in the 1920s as a treatment option for epilepsy, and especially in the last 30 years, has gained popularity for its potential benefits in a variety of neurological conditions other than epilepsy. This prompted us to perform a literature survey regarding the effect of KD on the onset and progression of MS. The here reviewed 15 original research articles including in vitro, preclinical, and clinical studies provide evidence for the safety and feasibility of the KD in MS, showing potential neuroprotective effects and positive impacts on cellular metabolism and disease outcome. Since the literature is limited and most studies were conducted with low numbers of MS patients and rather exploratory in nature, further studies with larger cohorts are needed to gain a better understanding of the mechanisms by which the improvements of the MS disease course are achieved.

Methylglyoxal suppresses microglia inflammatory response through NRF2-IκBζ pathway.

Methylglyoxal (MGO) is a highly reactive metabolite generated by glycolysis. Although abnormal accumulation of MGO has been reported in several autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, the role of MGO in autoimmune diseases has not yet been fully investigated. In this study, we found that the intracellular MGO levels increased in activated immune cells, such as microglia and lymphocytes. Treatment with MGO inhibited inflammatory cell accumulation in the spinal cord and ameliorated the clinical symptoms in EAE mice. Further analysis indicated that MGO suppressed M1-polarization of microglia cells and diminished their inflammatory cytokine production. MGO also inhibited the ability of microglial cells to recruit and activate lymphocytes by decreasing chemokine secretion and expression of co-stimulatory molecules. Furthermore, MGO negatively regulated glycolysis by suppressing glucose transporter 1 expression. Mechanically, we found that MGO could activate nuclear factor erythroid 2-related factor 2 (NRF2) pathway and NRF2 could bind to the promoter of IκBζ gene and suppressed its transcription and subsequently pro-inflammatory cytokine production. In conclusion, our results showed that MGO acts as an immunosuppressive metabolite by activating the NRF2-IκBζ.

Osteopontin expression and the effect of anti-VLA-4 mAb treatment in experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis.

INTRODUCTION: Osteopontin (OPN) is involved in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). The aim of this study was to investigate the expression of OPN in spinal cords of mice in the successive phases of EAE, to compare it with the density of inflammatory cells, oligodendrocytes and with the expression of interleukin (IL)-17A and to assess the effect of anti-α4ß1 integrin (VLA-4) treatment. MATERIAL AND METHODS: Experimental autoimmune encephalomyelitis (EAE) mice were injected with anti-VLA-4 antibodies or, as treatment control, with immunoglobulin G (IgG). Spinal cords were sectioned and immunostained for OPN, CD45 (overall leukocytes), CD3 (T cells), Iba1 (activated macrophages/microglia), IL-17A, and CNP1 (oligodendrocytes). Microscopic images were analysed and the percentage of immunopositive areas encompassing the whole spinal cord cross-sectional area were assessed in images for each antigen. RESULTS: Osteopontin was expressed by inflammatory cells and by a minority of neurons and blood vessels. Most of the studied parameters followed the temporal pattern of clinical scores: increase in the peak phase and decrease in the chronic phase. Only OPN and IL-17A remained at a high level in the chronic phase, while CNP1 expression gradually decreased in the successive phases. Anti-VLA-4 treatment lowered the expression of the studied antigens in the peak and chronic phases with the exception of oligodendrocyte marker CNP1 which in both phases showed an increased expression. CONCLUSIONS: Involvement of OPN is particularly significant in advanced EAE. Anti-VLA-4 treatment not only inhibits migration of myelin-reactive T cells, but also downregulates OPN and inhibits loss of oligodendrocytes.