The evidence for a role of B cells in multiple sclerosis

Multiple sclerosis: an immune attack on astrocyte-mediated ion and water homeostasis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. The chain of events that results in demyelinating lesions is not understood, although most theories assume a primary immune attack on myelin. However, the glial cell adhesion molecule GlialCAM, which forms part of a protein complex in astrocytic endfeet that is crucial for brain ion and water homeostasis, was recently identified as a target for autoimmunity in patients with MS. This complex also includes the astrocytic transmembrane protein MLC1, the water channel aquaporin 4 (AQP4) and the potassium channel KIR4.1. Autoimmunity against AQP4 underlies another demyelinating disorder, neuromyelitis optica, and autoimmunity against KIR4.1 has been implicated in a subtype of MS. Genetic defects in any of these proteins cause leukodystrophies with disruption of brain ion and water homeostasis, which is regulated by astrocytes and secondarily affects myelin. In this Perspective, we argue that an immune attack on the ion and water homeostasis machinery in astrocytic endfeet, rather than directly on myelin, is the primary event in MS and that myelin damage is a consequence of astrocyte dysfunction. This hypothesis is supported by pathological studies on tissue from people with MS and has important implications for disease models and therapy targets.

Immune response profiling of HERV-W envelope proteins in multiple sclerosis: potential biomarkers for disease progression

Introduction

The envelope proteins syncytin-1 and pHERV-W from the Human Endogenous Retroviral family 'W' (HERV-W) have been identified as potential risk factors in multiple sclerosis (MS). This study aims to evaluate both humoral and cell-mediated immune response to antigenic peptides derived from these proteins across different clinical forms and inflammatory phases of MS.

Methods

Indirect enzyme-linked immunosorbent assay (ELISA) was employed to measure immunoglobulin G (IgG) responses to syncytin-1env 486-500 and pHERV-Wenv 486-504 peptides in MS patients. Discriminant analysis was used to assess whether clinical course prediction could be enhanced by integrating clinical variables with humoral response data against other MS-associated viral factors. Additionally, peripheral blood mononuclear cells from MS patients and healthy controls (HC) were analyzed for inflammatory responses following stimulation with these peptides.

Results

MS patients exhibited significantly elevated antibody titers against -pHERV-Wenv 486-504 and syncytin-1env 486-500 compared to HCs, with the highest levels observed in progressive MS forms. Discriminant analysis accurately predicted the clinical course in 75.3% of the cases, with an 85% accuracy rate for progressive MS. In vitro, stimulation with pHERV-Wenv 486-504 led to a notable increase in pro-inflammatory cytokine production by CD4, CD8, and CD19 cells compared to syncytin-1env 486-500. A strong correlation was found between pHERV- Wenv 486-504 induced cytokine production and EBV and CMV titers in MS patients.

Discussion

These findings suggest that the pHERV-W envelope protein could be a valuable biomarker for monitoring peripheral inflammation in MS.

The presence of Mott cells in the lymph nodes of rats with experimental autoimmune encephalomyelitis

Mott cells are plasma cells that have multiple spherical Russell bodies packed in their cytoplasm. Russell bodies are dilated endoplasmic reticulum cisternae filled with aggregates of immunoglobulins that are neither secreted nor degraded. Mott cells were observed in our study by light and electron microscope in the lymph nodes of rats with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Mott cells were detected on hematoxylin and eosin (HE)-stained lymph node sections as vacuolated cells with eccentrically positioned nuclei and large number of faint blue spherical inclusions in the cytoplasm. Electron microscopic investigation revealed the presence of Russell bodies of the "medusa" form inside Mott cells in lymph node ultra-thin sections of EAE animals. Mott cells expressed the plasma cell marker CD138 and either kappa or lambda immunoglobulin light chains, indicating their origin from polyclonally activated B cells. Finally, Mott cells were associated with active EAE, as they were not found in the lymph nodes of EAE-resistant Albino Oxford rats. The presence of Russell bodies implies an excessive production of immunoglobulins in EAE, thus further emphasizing the role of B cells, and among them Mott cells, in the pathogenesis of this animal model of multiple sclerosis.

How Early Is Early Multiple Sclerosis?

The development and further optimization of the diagnostic criteria for multiple sclerosis (MS) emphasize the establishment of an early and accurate diagnosis. So far, numerous studies have revealed the significance of early treatment administration for MS and its association with slower disease progression and better late outcomes of the disease with regards to disability accumulation. However, according to current research results, both neuroinflammatory and neurodegenerative processes may exist prior to symptom initiation. Despite the fact that a significant proportion of individuals with radiologically isolated syndrome (RIS) progress to MS, currently, there is no available treatment approved for RIS. Therefore, our idea of "early treatment administration" might be already late in some cases. In order to detect the individuals who will progress to MS, we need accurate biomarkers. In this review, we present notable research results regarding the underlying pathology of MS, as well as several potentially useful laboratory and neuroimaging biomarkers for the identification of high-risk individuals with RIS for developing MS. This review aims to raise clinicians' awareness regarding "subclinical" MS, enrich their understanding of MS pathology, and familiarize them with several potential biomarkers that are currently under investigation and might be used in clinical practice in the future for the identification of individuals with RIS at high risk for conversion to definite MS.

Cladribine Effects on T and B Cells and T Cell Reactivity in Multiple Sclerosis

OBJECTIVE

Cladribine tablet therapy is an efficacious treatment for multiple sclerosis (MS), however, its mechanism of action on T and B cell subsets remains unclear. The purpose of this study was to investigate the treatment effects of cladribine on the peripheral pool of T and B cells subsets and reactivity toward central nervous system (CNS) antigens.

METHODS

In this cross-sectional exploratory study, frequencies and absolute counts of peripheral T and B cell subsets and B cell cytokine production from untreated patients with relapsing-remitting MS (RRMS) and patients treated with cladribine for 1 year were measured using flow cytometry. Autoreactivity was assessed using a FluoroSpot assay.

RESULTS

We found that 1 year after initiation of cladribine treatment, a lower number of CD4+ T cells was persisting whereas CD19+ B cell counts were normalized compared to untreated patients with RRMS. Follicular helper T cells and their effecter subsets producing cytokines exerting distinct B cell helper activity were lower and, additionally, the peripheral B cell pool was skewed toward a naïve and anti-inflammatory phenotype. Finally, reactivity to the recently identified CNS-enriched autoantigen RAS guanyl-releasing protein 2 (RASGRP2), but not to myelin basic protein and myelin oligodendrocyte glycoprotein, was lower in cladribine-treated patients.

INTERPRETATION

Together, these investigations on T and B cell subsets suggest that cladribine treatment impairs the B-T cell crosstalk and reduces their ability to mediate pathogenic effector functions. This may result in specific reduction of autoreactivity to RASGRP2 which is expressed in B cells and brain tissue. ANN NEUROL 2023;94:518-530.

Quantification of the Therapeutic Antibody Ocrelizumab in Mouse Brain Interstitial Fluid Using Cerebral Open Flow Microperfusion and Simultaneous Monitoring of the Blood-Brain Barrier Integrity

The increasing relevance of improved therapeutic monoclonal antibodies (mAbs) to treat neurodegenerative diseases has strengthened the need to reliably measure their brain pharmacokinetic (PK) profiles. The aim of this study was, therefore, to absolutely quantify the therapeutic antibody ocrelizumab (OCR) as a model antibody in mouse brain interstitial fluid (ISF), and to record its PK profile by using cerebral open flow microperfusion (cOFM). Further, to monitor the blood-brain barrier (BBB) integrity using an endogenous antibody with a similar molecular size as OCR. The study was conducted on 13 male mice. Direct and absolute OCR quantification was performed with cOFM in combination with zero flow rate, and subsequent bioanalysis of the obtained cerebral ISF samples. For PK profile recording, cerebral ISF samples were collected bi-hourly, and brain tissue and plasma were collected once at the end of the sampling period. The BBB integrity was monitored during the entire PK profile recording by using endogenous mouse immunoglobulin G1. We directly and absolutely quantified OCR and recorded its brain PK profile over 96 h. The BBB remained intact during the PK profile recording. The resulting data provide the basis for reliable PK assessment of therapeutic antibodies in the brain thus favoring the further development of therapeutic monoclonal antibodies.

PALM: a powerful and adaptive latent model for prioritizing risk variants with functional annotations

MOTIVATION

The findings from genome-wide association studies (GWASs) have greatly helped us to understand the genetic basis of human complex traits and diseases. Despite the tremendous progress, much effects are still needed to address several major challenges arising in GWAS. First, most GWAS hits are located in the non-coding region of human genome, and thus their biological functions largely remain unknown. Second, due to the polygenicity of human complex traits and diseases, many genetic risk variants with weak or moderate effects have not been identified yet.

RESULTS

To address the above challenges, we propose a powerful and adaptive latent model (PALM) to integrate cell-type/tissue-specific functional annotations with GWAS summary statistics. Unlike existing methods, which are mainly based on linear models, PALM leverages a tree ensemble to adaptively characterize non-linear relationship between functional annotations and the association status of genetic variants. To make PALM scalable to millions of variants and hundreds of functional annotations, we develop a functional gradient-based expectation-maximization algorithm, to fit the tree-based non-linear model in a stable manner. Through comprehensive simulation studies, we show that PALM not only controls false discovery rate well, but also improves statistical power of identifying risk variants. We also apply PALM to integrate summary statistics of 30 GWASs with 127 cell type/tissue-specific functional annotations. The results indicate that PALM can identify more risk variants as well as rank the importance of functional annotations, yielding better interpretation of GWAS results.

AVAILABILITY AND IMPLEMENTATION

The source code is available at https://github.com/YangLabHKUST/PALM.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Ocrelizumab effect on humoral and cellular immunity in multiple sclerosis and its clinical correlates: a 3-year observational study

OBJECTIVE

We aim to evaluate 3-year effects of ocrelizumab (humanized anti-CD20 monoclonal antibody for the treatment of multiple sclerosis (MS)) on lymphocytes, neutrophils and immunoglobulins: (1) when compared with pre-infusion assessment; (2) over the course of treatment; and (3) possible clinical correlates of the observed immunological modifications.

METHODS

This real-world observational cohort study has been conducted on prospectively collected data from 78 MS patients (mean age 47.8 ± 10.5 years; females 48.7%) commencing on ocrelizumab from 2018, with mean follow-up of 36.5 ± 6.8 months. Clinical data and blood samples were collected every three months. Total lymphocyte count and subpopulations were assessed on peripheral blood using flow cytometry. Serum immunoglobulins were evaluated with nephelometry.

RESULTS

When compared with pre-infusion values, we observed reduction of total, CD19 and CD20 lymphocyte counts; however, after the first infusion, their levels remained substantially stable. Over time we observed a progressive reduction of CD8 lymphocytes, while no changes were observed for CD4, CD27, CD3CD27, and CD19CD27. After the first infusion, we observed reduction in IgG, which further decreased during the follow-up. Higher probability of EDSS progression was associated with reduced modulation of CD8 lymphocytes.

INTERPRETATION

Ocrelizumab affects both humoral and cellular immune responses. Disability progression over the follow-up was associated with lower CD8 cytotoxic T-lymphocyte reduction. Changes in humoral response are immediate and sustained, while modulation of cellular immunity occurs progressively through regular re-treatment, and is related to clinical stability.

Current Perspectives: Evidence to Date on BTK Inhibitors in the Management of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system leading to demyelination and neurodegeneration. Basic and translational studies have shown that B cells and myeloid cells are critical players for the development and course of the disease. Bruton's tyrosine kinase (BTK) is essential for B cell receptor-mediated B cell activation and for normal B cell development and maturation. In addition to its role in B cells, BTK is also involved in several functions of myeloid cells. Although significant number of disease-modifying treatments (DMTs) have been approved for clinical use in MS patients, novel targeted therapies should be studied in refractory patients and patients with progressive forms of the disease. On the basis of its role in B cells and myeloid cells, BTK inhibitors can provide attractive therapeutic benefits for MS. In this article, we review the main effects of BTK inhibitors on different cell types involved in the pathogenesis of MS and summarise recent advances in the development of BTK inhibitors as novel therapeutic approaches in different MS clinical trials. Available data regarding the efficacy and safety of these drugs are described.

Nanoformulated Recombinant Human Myelin Basic Protein and Rituximab Modulate Neuronal Perturbations in Experimental Autoimmune Encephalomyelitis in Mice

Introduction

Rituximab (RTX) and recombinant human myelin basic protein (rhMBP) were proven to be effective in ameliorating the symptoms of multiple sclerosis (MS). In this study, a nanoformulation containing rhMBP with RTX on its surface (Nano-rhMBP-RTX) was prepared and investigated in comparison with other treatment groups to determine its potential neuro-protective effects on C57BL/6 mice after inducing experimental autoimmune encephalomyelitis (EAE).

Methods

EAE was induced in the corresponding mice by injecting 100 μL of an emulsion containing complete Freund's adjuvant (CFA) and myelin oligodendrocyte glycoprotein (MOG). The subjects were weighed, scored and subjected to behavioural tests. After reaching a clinical score of 3, various treatments were given to corresponding EAE-induced and non-induced groups including rhMBP, RTX, empty nanoparticle prepared by poly (lactide-co-glycolide) (PLGA) or the prepared nanoformulation (Nano-rhMBP-RTX). At the end of the study, biochemical parameters were also determined as interferon-γ (IFN-γ), myeloperoxidase (MPO), interleukin-10 (IL-10), interleukin-4 (IL-4), tumor necrosis factor alpha (TNF-α), nuclear factor kappa B (NF-kB), brain derived neurotrophic factor (BDNF), 2', 3' cyclic nucleotide 3' phosphodiesterase (CNP) and transforming growth factor beta (TGF-β) along with some histopathological analyses.

Results

The results of the Nano-rhMBP-RTX group showed promising outcomes in terms of reducing the clinical scores, improving the behavioural responses associated with improved histopathological findings. Elevation in the levels of IL-4, CNP and TGF-β was also noticed along with marked decline in the levels of NF-kB and TNF-α.

Conclusion

Nano-rhMBP-RTX treated group ameliorated the adverse effects induced in the EAE model. The effectiveness of this formulation was demonstrated by the normalization of EAE-induced behavioral changes and aberrant levels of specific biochemical markers as well as reduced damage of hippocampal tissues and retaining higher levels of myelination.

Unmet Needs and Treatment of Relapsing-Remitting Multiple Sclerosis in Saudi Arabia: Focus on the Role of Ofatumumab

Treatment-pattern data suggest that some patients with multiple sclerosis (MS) in the Kingdom of Saudi Arabia (KSA) may not be receiving optimal treatment. A virtual meeting of ten expert Saudi neurologists, held on October 23, 2020, discussed unmet needs in relapsing-remitting MS (RRMS), and the role of ofatumumab as a suitable treatment in the KSA. Multiple unmet needs were identified: poor quality of life, with high rates of depression and anxiety; a negative impact of MS on work ability; treatment choices that may compromise efficacy for safety or vice versa; inconvenient or complex dosage regimens; and limited access to patient education and support. Early use of highly effective disease-modifying treatments (DMTs) results in better patient outcomes than starting with less effective treatments and downstream escalation, but this strategy may be underutilized in the KSA. B cells are important in MS pathogenesis, and treatments targeting these may improve clinical outcomes. Ofatumumab differs from other B cell-depleting therapies, being a fully human monoclonal antibody that binds to CD20 at a completely separate site from the epitope bound by ocrelizumab, and being administered by subcutaneous injection. When compared with teriflunomide in two randomized, phase 3 clinical trials in patients with RRMS, ofatumumab was associated with significant reductions in annualized relapse rates, rates of confirmed disability worsening, and active lesions on magnetic resonance imaging. The incidence of adverse events, including serious infections, was similar with the two treatments. Ofatumumab is a valuable first- or second-line treatment option for RRMS in the KSA, particularly for patients who would benefit from highly effective DMTs early in the disease course, and for those who prefer the convenience of self-injection. Future research will clarify the position of ofatumumab in RRMS treatment, and comparative cost data may support the broad inclusion of ofatumumab in formularies across the KSA.

Increased Intrathecal Activity of Follicular Helper T Cells in Patients With Relapsing-Remitting Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Follicular helper T (Tfh) cells play a critical role in protective immunity helping B cells produce antibodies against foreign pathogens and are likely implicated in the pathogenesis of various autoimmune diseases. The purpose of this study was to investigate the role of Tfh cells in the pathogenesis of multiple sclerosis (MS).

METHODS

Using flow cytometry, we investigated phenotype, prevalence, and function of Tfh cells in blood and CSF from controls and patients with relapsing-remitting MS (RRMS) and primary progressive MS (PPMS). In addition, an in vitro blood-brain barrier coculture assay of primary human astrocytes and brain microvascular endothelial cells grown in a Boyden chamber was used to assess the migratory capacity of peripheral Tfh cells.

RESULTS

This study identified 2 phenotypically and functionally distinct Tfh cell populations: CD25^- Tfh cells (Tfh1-like) and CD25^int Tfh cells (Tfh17-like). Whereas minor differences in Tfh cell populations were found in blood between patients with MS and controls, we observed an increased frequency of CD25^- Tfh cells in CSF of patients with RRMS and PPMS and CD25^int Tfh cells in patients with RRMS, compared with controls. Increasing frequencies of CSF CD25^- Tfh cells and the CD25^- Tfh/Tfr ratio scaled with increasing IgG index in patients with RRMS. Despite an increased prevalence of intrathecal Tfh cells in patients with MS, no difference in the migratory capacity of circulating Tfh cells was observed between controls and patients with MS. Instead, CSF concentrations of CXCL13 scaled with total counts of Tfh and Tfr cell subsets in the CSF.

DISCUSSION

Our study indicates substantial changes in intrathecal Tfh dynamics, particularly in patients with RRMS, and suggests that the intrathecal inflammatory environment in patients with RRMS promotes recruitment of peripheral Tfh cells rather than the Tfh cells having an increased capacity to migrate to CNS.

Biological Markers in Early Multiple Sclerosis: the Paved Way for Radiologically Isolated Syndrome

Radiologically Isolated Syndrome (RIS) is characterized by MRI-typical brain lesions fulfilling the 2009 Okuda criteria, detected in patients without clinical conditions suggestive of MS. Half of all RIS patients convert to MS within 10 years. The individual course of the disease, however, is highly variable with 12% of RIS converting directly to progressive MS. Demographic and imaging markers have been associated with the risk of clinical MS in RIS: male sex, younger age, infra-tentorial, and spinal cord lesions on the index scan and gadolinium-enhancing lesions on index or follow-up scans. Although not considered as a distinct MS phenotype, RIS certainly shares common pathological features with early active and progressive MS. In this review, we specifically focus on biological markers that may help refine the risk stratification of clinical MS and disability for early treatment. Intrathecal B-cell activation with cerebrospinal fluid (CSF) oligoclonal bands, elevated kappa free light chains, and cytokine production is specific to MS, whereas neurofilament light chain (NfL) levels reflect disease activity associated with neuroaxonal injury. Specific microRNA profiles have been identified in RIS converters in both CSF and blood. CSF levels of chitinases and glial acidic fibrillary protein (GFAP) reflecting astrogliosis might help predict the evolution of RIS to progressive MS. Innovative genomic, proteomic, and metabolomic approaches have provided several new candidate biomarkers to be explored in RIS. Leveraging data from randomized controlled trials and large prospective RIS cohorts with extended follow-up to identify, as early as possible, biomarkers for predicting greater disease severity would be invaluable for counseling patients, managing treatment, and monitoring.

Peripheral helper T cells in the pathogenesis of multiple sclerosis

BACKGROUND

Peripheral helper T cells (Tph) are likely implicated in the pathogenesis of various inflammatory diseases. Tph cells share functions with follicular helper T cells, including plasma cell differentiation and antibody production.

OBJECTIVE AND METHODS

To investigate a possible role of Tph cells in the pathogenesis of multiple sclerosis (MS), we used flow cytometry to analyze the function, phenotype, and central nervous system (CNS)-recruitment of Tph cells in the blood and cerebrospinal fluid (CSF) from controls and patients with relapsing-remitting (RR) and primary progressive (PP) MS.

RESULT

This study identified two functionally distinct Tph cell populations and a regulatory counterpart, Tpr cells. No differences in blood frequencies, cytokine production, or potential to interact with B cells were found between controls and patients with MS. Along with an equal CNS-migration potential, we found both Tph cell populations enriched in the CSF; and surprisingly, an increased frequency of intrathecal Tph cells in the control group compared to patients with MS.

CONCLUSION

Altogether, we did not find an increased frequency of CSF Tph cells in patients with RRMS or PPMS. Our findings indicate that rather than being involved in MS pathogenesis, Tph cells may be implicated in normal CNS immunosurveillance.

The Molecular Mechanisms Through Which Placental Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Myelin Regeneration

Multiple sclerosis (MS) is a debilitating degenerative disease characterized by an immunological attack on the myelin sheath leading to demyelination and axon degeneration. Mesenchymal stem/stromal cells (MSCs) and secreted extracellular vesicles (EVs) have become attractive targets as therapies to treat neurodegenerative diseases such as MS due to their potent immunomodulatory and regenerative properties. The placenta is a unique source of MSCs (PMSCs), demonstrates "fetomaternal" tolerance during pregnancy, and serves as a novel source of MSCs for the treatment of neurodegenerative diseases. PMSCs and PMSC-EVs have been shown to promote remyelination in animal models of MS, however, the molecular mechanisms by which modulation of autoimmunity and promotion of myelination occurs have not been well elucidated. The current review will address the molecular mechanisms by which PMSC-EVs can promote remyelination in MS.

Cerebrospinal fluid evaluation in patients with progressive motor impairment due to critical central nervous system demyelinating lesions

Background

Elevated intrathecal immunoglobulin G (IgG; oligoclonal bands (OCBs)) or IgG in people with progressive motor impairment due to “critical” demyelinating lesions are of uncertain significance.

Objective

Compare clinical/radiological features of people with “critical” demyelinating lesion-induced progressive motor impairment with/without elevated intrathecal IgG synthesis.

Methods

A total of 133 people with progressive motor impairment attributable to “critical” demyelinating lesions (corticospinal tract location, consistent with the progressive motor deficit) were compared regarding clinical and radiological presentation with and without ≥2 unique cerebrospinal fluid (CSF) OCB and/or IgG index ≥0.85.

Results

Ninety-eight (74%) had CSF-elevated OCB and/or IgG index, higher with increased magnetic resonance imaging-lesion burden. No differences were found with/without CSF abnormalities in sex (46 of 98 female (47%) vs. 22 of 35 (63%), p = 0.11), onset-age (median 49 vs. 50 years, p = 0.5), progression from onset (62 of 98 (63%) vs. 25 of 35 (71%)), progression post-relapse (36 of 98 (37%) vs. 10 of 35 (29%), p = 0.4), and duration between demyelinating disease onset and CSF examination (30 (0–359) vs. 48 (0–323) months p = 0.7). “Critical” lesions were radiologically similar, most commonly cervical spine located (72 of 98 (74%) vs. 19 of 35 (54%), p = 0.18) both with/without CSF abnormalities.

Conclusions

People with “critical” demyelinating lesion-induced progressive motor impairment typically have elevated intrathecal IgG (OCB and/or IgG) and similar clinical and radiological presentation regardless of CSF findings, therefore representing valid presentations of progressive demyelinating disease.

Rituximab for the treatment of multiple sclerosis: a review

In the last decades, evidence suggesting the direct or indirect involvement of B cells on multiple sclerosis (MS) pathogenesis has accumulated. The increased amount of data on the efficacy and safety of B-cell-depleting therapies from several studies has suggested the addition of these drugs as treatment options to the current armamentarium of disease modifying therapies (DMTs) for MS. Particularly, rituximab (RTX), a chimeric monoclonal antibody directed at CD20 positive B lymphocytes resulting in cell-mediated apoptosis, has been demonstrated to reduce inflammatory activity, incidence of relapses and new brain lesions on magnetic resonance imaging (MRI) in patients with relapsing-remitting MS (RRMS). Additional evidence also demonstrated that patients with progressive MS (PMS) may benefit from RTX, which also showed to be well tolerated, with acceptable safety risks and favorable cost-effectiveness profile.Despite these encouraging results, RTX is currently approved for non-Hodgkin's lymphoma, chronic lymphocytic leukemia, several forms of vasculitis and rheumatoid arthritis, while it can only be administered off-label for MS treatment. Between Northern European countries exist different rules for using not licensed drug for treating MS. The Sweden MS register reports a high rate (53.5%) of off-label RTX prescriptions in relation to other annually started DMTs to treat MS patients, while Danish and Norwegian neurologists have to use other anti-CD20 drugs, as ocrelizumab, in most of the cases.In this paper, we review the pharmacokinetics, pharmacodynamics, clinical efficacy, safety profile and cost effectiveness aspects of RTX for the treatment of MS. Particularly, with the approval of new anti-CD20 DMTs, the recent worldwide COVID-19 emergency and the possible increased risk of infection with this class of drugs, this review sheds light on the use of RTX as an alternative treatment option for MS management, while commenting the gaps of knowledge regarding this drug.

B cell modulation with anti-CD79bantibodies ameliorates experimental autoimmune encephalitis in mice

B cells play a major role in the pathogenesis of many autoimmune diseases like multiple sclerosis, rheumatoid arthritis or systemic lupus erythematosus. Depletion of B cells with anti-CD20 antibodies is an established therapy for multiple sclerosis. However, total B cell depletion will also affect regulatory B cells that are known to suppress autoimmune responses. In our studies we describe an alternative approach based on targeting of CD79b that induces only partial B cell depletion and achieves therapeutic effects by B cell modulation. Prophylactic and therapeutic treatment with an antibody against CD79b and also a deglycosylated variant of this antibody, lacking effector function like antibody-dependent cellular cytotoxicity or complement activation, significantly reduced the development and progression of experimental autoimmune encephalitis (EAE) in mice. Our data show that modulation of B cells via CD79b is equally effective as almost complete B cell depletion with anti-CD20 antibodies and may constitute an alternative approach to treat multiple sclerosis. This article is protected by copyright. All rights reserved.

Expression of Akt1 and p-Akt1 in peripheral T cell subsets of multiple sclerosis patients

Multiple sclerosis is an autoimmune disorder induced by the infiltration of autoreactive immune cells into the central nervous system. Akt/PKB signaling pathway is crucially involved in T cell development and survival. We aimed to determine whether Akt1 expression levels of regulatory T (Treg) cells are altered in MS and are associated with disease activity. Relapsing-remitting multiple sclerosis (RR-MS, n = 17) patients and healthy individuals (n = 20) were enrolled. Peripheral blood mononuclear cells were isolated and anti-CD3, -CD4, -CD8, -CD25, -CD127 monoclonal antibodies were used to identify the T cell subsets. After stimulation with phorbol myristate acetate/ionomycin, the Akt1 and phosphorylated-Akt1 (p-Akt1) levels of T cell subsets were detected with intracellular staining using flow cytometry. Total Akt1 and p-Akt1 expression levels were found to be suppressed in CD4⁺ T cell and Treg populations of RR-MS patients. Progression indices were positively correlated with Akt1 expression levels of Tregs indicating that the Akt pathway might partake in the progression of multiple sclerosis. Flow cytometry may effectively be used for the evaluation of the Akt pathway activity. Our findings suggest that the magnitude of suppression of the Akt pathway might serve as a biomarker for the prognosis of multiple sclerosis.

Investigation of neuro-inflammatory parameters in a cuprizone induced mouse model of multiple sclerosis

Cuprizone, copper chelator, treatment of mouse is a toxic model of multiple sclerosis (MS) in which oligodendrocyte death, demyelination and remyelination can be observed. Understanding T and B cell subset as well as their cytokines involved in MS pathogenesis still requires further scrutiny to better understand immune component of MS. The study presented here, aimed to evaluate relevant cytokines, lymphocytes, and gene expressions profiles during demyelination and remyelination in the cuprizone mouse model of MS. Eighty male C57BL/6J mice fed with 0.2% cuprizone for eight weeks. Cuprizone has been removed from the diet in the following eight weeks. Cuprizone treated and control mice sacrificed biweekly, and corpus callosum of the brain was investigated by staining. Lymphocyte cells of mice analyzed by flow cytometry with CD3e, CD11b, CD19, CD80, CD86, CD4, CD25 and FOXP3 antibodies. IFN-gamma, IL-1alpha, IL-2, IL-5, IL-6, IL-10, IL-17, TNF-alpha cytokines were analyzed in plasma samples. Neuregulin 1 (Nrg1), ciliary neurotrophic factor (Cntf) and C-X-C chemokine receptor type 4 (Cxcr4) gene expressions in corpus callosum sections of the mice brain were quantified. Histochemistry analysis showed that demyelination began at the fourth week of cuprizone administration and total demyelination occurred at the twelfth week in chronic model. Remyelination occurred at the fourth week of following withdrawal of cuprizone from diet. The level of mature and activated T cells, regulatory T cells, T helper cells and mature B cells increased during demyelination and decreased when cuprizone removed from diet. Further, both type 1 and type 2 cytokines together with the proinflammatory cytokines increased. The level of oligodendrocyte maturation and survival genes showed differential gene expression in parallel to that of demyelination and remyelination. In conclusion, for the first-time, involvement of both cellular immune response and antibody response as well as oligodendrocyte maturation and survival factors having role in demyelination and remyelination of cuprizone mouse model of MS have been shown.

CD19 Cell Count at Baseline Predicts B Cell Repopulation at 6 and 12 Months in Multiple Sclerosis Patients Treated with Ocrelizumab

BACKGROUND

The kinetics of B cell repopulation in MS patients treated with Ocrelizumab is highly variable, suggesting that a fixed dosage and time scheduling might be not optimal. We aimed to investigate whether B cell repopulation kinetics influences clinical and radiological outcomes and whether circulating immune asset at baseline affects B cell repopulation kinetics.

METHODS

218 MS patients treated with Ocrelizumab were included. Every six months we collected data on clinical and magnetic resonance imaging (MRI) activity and lymphocyte subsets at baseline. According to B cell counts at six and twelve months, we identified two groups of patients, those with fast repopulation rate (FR) and those with slow repopulation rate (SR).

RESULTS

A significant reduction in clinical and radiological activity was found. One hundred fifty-five patients had complete data and received at least three treatment cycles (twelve-month follow-up). After six months, the FR patients were 41/155 (26.45%) and 10/41 (29.27%) remained non-depleted after twelve months. FR patients showed a significantly higher percentage of active MRI scan at twelve months (17.39% vs. 2.53%; p = 0,008). Furthermore, FR patients had a higher baseline B cell count compared to patients with an SR (p = 0.02 and p = 0.002, at the six- and twelve-month follow-ups, respectively).

CONCLUSION

A considerable proportion of MS patients did not achieve a complete CD19 cell depletion and these patients had a higher baseline CD19 cell count. These findings, together with the higher MRI activity found in FR patients, suggest that the Ocrelizumab dosage could be tailored depending on CD19 cell counts at baseline in order to achieve complete disease control in all patients.

The Assessment of Serum Concentrations of AGEs and Their Soluble Receptor (sRAGE) in Multiple Sclerosis Patients

BACKGROUND

Advanced glycation end products (AGEs) are involved in the pathogenesis of many diseases, including neurodegenerative diseases such as multiple sclerosis (MS). The aim of the study was to determine serum concentrations of AGEs and their soluble receptor (sRAGE) in MS patients and healthy controls and to investigate their possible influence on disease activity.

METHODS

Serum concentrations of AGE and sRAGE in patients with MS and healthy controls were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean serum AGE concentration in patients with MS was higher than in healthy controls, whereas the mean serum sRAGE concentration was lower than in the control group. However, the differences were not statistically significant. In MS patients, serum AGE and sRAGE concentrations did not differ significantly, depending on the duration of the disease and the Expanded Disability Status Scale (EDSS) score.

CONCLUSIONS

Multiple sclerosis may be accompanied by disturbances of the AGE-sRAGE axis. However, further studies are warranted to confirm it. The duration of the disease and the degree of disability do not seem to affect the progression of the glycation process, particularly in the stable phase of the disease.

Connecting Neuroinflammation and Neurodegeneration in Multiple Sclerosis: Are Oligodendrocyte Precursor Cells a Nexus of Disease?

The pathology in neurodegenerative diseases is often accompanied by inflammation. It is well-known that many cells within the central nervous system (CNS) also contribute to ongoing neuroinflammation, which can promote neurodegeneration. Multiple sclerosis (MS) is both an inflammatory and neurodegenerative disease in which there is a complex interplay between resident CNS cells to mediate myelin and axonal damage, and this communication network can vary depending on the subtype and chronicity of disease. Oligodendrocytes, the myelinating cell of the CNS, and their precursors, oligodendrocyte precursor cells (OPCs), are often thought of as the targets of autoimmune pathology during MS and in several animal models of MS; however, there is emerging evidence that OPCs actively contribute to inflammation that directly and indirectly contributes to neurodegeneration. Here we discuss several contributors to MS disease progression starting with lesion pathology and murine models amenable to studying particular aspects of disease. We then review how OPCs themselves can play an active role in promoting neuroinflammation and neurodegeneration, and how other resident CNS cells including microglia, astrocytes, and neurons can impact OPC function. Further, we outline the very complex and pleiotropic role(s) of several inflammatory cytokines and other secreted factors classically described as solely deleterious during MS and its animal models, but in fact, have many neuroprotective functions and promote a return to homeostasis, in part via modulation of OPC function. Finally, since MS affects patients from the onset of disease throughout their lifespan, we discuss the impact of aging on OPC function and CNS recovery. It is becoming clear that OPCs are not simply a bystander during MS progression and uncovering the active roles they play during different stages of disease will help uncover potential new avenues for therapeutic intervention.

Herpesviruses and the hidden links to Multiple Sclerosis neuropathology

Herpesviruses like Epstein-Barr virus, human herpesvirus (HHV)-6, HHV-1, VZV, and human endogenous retroviruses, have an age-old clinical association with multiple sclerosis (MS). MS is an autoimmune disease of the nervous system wherein the myelin sheath deteriorates. The most popular mode of virus mediated immune system manipulation is molecular mimicry. Numerous herpesvirus antigens are similar to myelin proteins. Other mechanisms described here include the activity of cytokines and autoantibodies produced by the autoreactive T and B cells, respectively, viral déjà vu, epitope spreading, CD46 receptor engagement, impaired remyelination etc. Overall, this review addresses the host-parasite association of viruses with MS.

Neuroprotective Effect of Apolipoprotein D in Cuprizone-Induced Cell Line Models: A Potential Therapeutic Approach for Multiple Sclerosis and Demyelinating Diseases

Apolipoprotein D (Apo D) overexpression is a general finding across neurodegenerative conditions so the role of this apolipoprotein in various neuropathologies such as multiple sclerosis (MS) has aroused a great interest in last years. However, its mode of action, as a promising compound for the development of neuroprotective drugs, is unknown. The aim of this work was to address the potential of Apo D to prevent the action of cuprizone (CPZ), a toxin widely used for developing MS models, in oligodendroglial and neuroblastoma cell lines. On one hand, immunocytochemical quantifications and gene expression measures showed that CPZ compromised neural mitochondrial metabolism but did not induce the expression of Apo D, except in extremely high doses in neurons. On the other hand, assays of neuroprotection demonstrated that antipsychotic drug, clozapine, induced an increase in Apo D synthesis only in the presence of CPZ, at the same time that prevented the loss of viability caused by the toxin. The effect of the exogenous addition of human Apo D, once internalized, was also able to directly revert the loss of cell viability caused by treatment with CPZ by a reactive oxygen species (ROS)-independent mechanism of action. Taken together, our results suggest that increasing Apo D levels, in an endo- or exogenous way, moderately prevents the neurotoxic effect of CPZ in a cell model that seems to replicate some features of MS which would open new avenues in the development of interventions to afford MS-related neuroprotection.

Intrathecally produced CXCL13: A predictive biomarker in multiple sclerosis

Background

Clinicians caring for patients with Multiple Sclerosis (MS) need improved biomarkers to aid them in disease management.

Objective

We assessed the predictive value of the candidate biomarker CXCL13 index in comparison to oligoclonal bands (OCBs) and CSF neurofilament light (NfL) concentration, examining the ability of each biomarker to predict future disease activity in clinically and radiologically isolated syndromes, relapsing-remitting MS, and progressive MS.

Methods

Matched serum and CSF samples were obtained from 67 non-inflammatory neurologic disease patients and 67 MS patients. CSF and serum CXCL13 and CSF NfL were analyzed by Luminex and ELISA, respectively. CXCL13 data were also analyzed as CSF/serum ratios and indices. Electronic medical records were accessed to determine diagnosis, CSF profiles, and disease activity after the lumbar puncture.

Results

Among CXCL13 measures, CXCL13 index was the best predictor of future disease activity in MS patients (AUC = 0.82; CI = 0.69–0.95; p = 0.0002). CXCL13 index values were significantly elevated in activity-positive MS patients compared to activity-negative patients (p < 0.0001). As a single predictor, CXCL13 index outperformed both OCBs and CSF NfL in sensitivity, specificity, and positive and negative predictive value, for future disease activity in MS patients. Moreover, combining CXCL13 index and CSF NfL status improved sensitivity and predictive values for disease activity in MS patients.

Conclusions

The CXCL13 index is an excellent candidate prognostic biomarker for disease activity in patients with MS.

Modulation by Anisakis simplex antigen of inflammatory response generated in experimental autoimmune encephalomyelitis

The impact of immunization with Anisakis simplex larval antigen on the occurrence and progression of experimental autoimmune encephalomyelitis (EAE) induced in mice was studied. C57BL/6J mice were immunized with the MOG_35-55 peptide and one batch was treated with A. simplex total larval antigen on days 1, 8, 10 and 12 after EAE induction. Significantly higher values were obtained in the EAE clinical parameters of the antigen-treated group. Likewise, there was a significant decrease in the weights of the animals. Anisakis-treatment produced a significant decrease in anti-MOG_35-55 specific IgG1 on day 21. On day 14 there was an increase in serum IL-2, IL-6, IL-10, IL-17A, and TGF-β in the treated group. On day 21, a decrease in IL-4, IL-6, TNF-α, TGF-β was observed. All brain determinations were made on day 21. The treatment decreased values of IL-6, IL-10, IL-17A and TNF-α. A. simplex antigen caused a significantly higher incidence of EAE and an advance in the appearance of the disease manifestations. However, treatment with the antigen was able to cause a decrease in proinflammatory cytokines (IL-6, IL-17A, and TNF-α) in nervous tissue that could establish a future preventive scenario for myelin damage.

Tumefactive Acute Disseminated Encephalomyelitis

Tumefactive demyelination is a phenomenon involving the radiographic resemblance of an acute demyelinating process in the central nervous system to neoplasia. Although this has been described and characterized for multiple sclerosis, it has been reported in a few cases in patients with acute disseminated encephalomyelitis (ADEM) within the past decade. While it may be challenging to establish a diagnosis of tumefactive ADEM according to clinical and radiological data alone, a thorough review of the clinical history and following the patient over time can be supportive of the same. The principal diagnostic confounds include neoplastic disease and a first attack of multiple sclerosis. A definitive diagnosis can be made by biopsy, which reveals perivenular demyelination and mononuclear cell infiltration in ADEM, in contrast to confluent plaque-like areas of demyelination in patients with multiple sclerosis. Histopathologic evidence of neoplastic disease includes characteristic features, including nuclear atypia and polymorphism, cellular hyperproliferation, mitoses, necrosis, endothelial proliferation, rosettes, and/or pseudorosettes. ADEM responds excellently to treatment with corticosteroids and is monophasic, with recurrence occurring infrequently. We review the literature on tumefactive ADEM and discuss the clinical manifestations, imaging characteristics, and histopathologic findings used to distinguish it from other conditions.

Coagulation/Complement Activation and Cerebral Hypoperfusion in Relapsing-Remitting Multiple Sclerosis

Introduction

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system with an underlying immune-mediated and inflammatory pathogenesis. Innate immunity, in addition to the adaptive immune system, plays a relevant role in MS pathogenesis. It represents the immediate non-specific defense against infections through the intrinsic effector mechanism “immunothrombosis” linking inflammation and coagulation. Moreover, decreased cerebral blood volume (CBV), cerebral blood flow (CBF), and prolonged mean transit time (MTT) have been widely demonstrated by MRI in MS patients. We hypothesized that coagulation/complement and platelet activation during MS relapse, likely during viral infections, could be related to CBF decrease. Our specific aims are to evaluate whether there are differences in serum/plasma levels of coagulation/complement factors between relapsing-remitting (RR) MS patients (RRMS) in relapse and those in remission and healthy controls as well as to assess whether brain hemodynamic changes detected by MRI occur in relapse compared with remission. This will allow us to correlate coagulation status with perfusion and demographic/clinical features in MS patients.

Materials and Methods

This is a multi-center, prospective, controlled study. RRMS patients (1° group: 30 patients in relapse; 2° group: 30 patients in remission) and age/sex-matched controls (3° group: 30 subjects) will be enrolled in the study. Patients and controls will be tested for either coagulation/complement (C3, C4, C4a, C9, PT, aPTT, fibrinogen, factor II, VIII, and X, D-dimer, antithrombin, protein C, protein S, von-Willebrand factor), soluble markers of endothelial damage (thrombomodulin, Endothelial Protein C Receptor), antiphospholipid antibodies, lupus anticoagulant, complete blood count, viral serological assays, or microRNA microarray. Patients will undergo dynamic susceptibility contrast-enhanced MRI using a 3.0-T scanner to evaluate CBF, CBV, MTT, lesion number, and volume.

Statistical Analysis

ANOVA and unpaired t-tests will be used. The level of significance was set at p ≤ 0.05.

Discussion

Identifying a link between activation of coagulation/complement system and cerebral hypoperfusion could improve the identification of novel molecular and/or imaging biomarkers and targets, leading to the development of new effective therapeutic strategies in MS.

Clinical Trial Registration

Clinicaltrials.gov, identifier NCT04380220.

Carboxymethyllysine and carboxyethyllysine in multiple sclerosis patients

Introduction

Advanced glycation end-products (AGE) are involved in the pathogenesis of many diseases, including neurodegenerative diseases such as multiple sclerosis (MS). The aim of the study was to evaluate the intensity of the protein glycation process in patients with multiple sclerosis and its possible involvement in disease activity.

Material and methods

The study group (n = 45) consisted of patients suffering from MS, and the control group (n = 31) consisted of healthy adults. Concentrations of selected glycation markers such as carboxymethyllysine (CML) and carboxyethyllysine (CEL) in sera of patients with MS and healthy volunteers were determined by enzyme-linked immunosorbent assay (ELISA).

Results

Serum CML and CEL concentrations in patients with MS were higher than in healthy volunteers but only for CML the difference was statistically significant. CML concentrations positively correlated with CEL concentrations only in the healthy persons. In MS patients the serum CML and CEL concentrations did not differ significantly depending on the duration of the disease and depending on the EDSS (Expanded Disability Status Scale) score.

Conclusions

Multiple sclerosis is accompanied by an intensification of protein glycation processes, especially within the pathways leading to the formation of carboxymethyllysine. The duration of the disease and the degree of motor impairment do not appear to affect the progression of the glycation processes. However, the disease process associated with multiple sclerosis may affect the relationship between CML and CEL concentrations.

Anti-neurofilament antibodies and neurodegeneration: Markers and generators

Neuroaxonal injury and loss result in the release of cytoskeleton components, including neurofilaments, into the cerebrospinal fluid and peripheral blood. Once released, neurofilaments are highly immunogenic, inducing a specific antibody response. Anti-neurofilament antibody levels correlate with the progression of diverse neurological diseases; however, their role both in the pathogenesis of disease and as a tool for monitoring disease progression is not well understood. This study reviews the current literature on anti-neurofilament antibodies. We suggest the testing of anti-neurofilament antibodies be further developed for diagnosis and targeted for treatment.

Towards a comprehensive etiopathogenetic and pathophysiological theory of multiple sclerosis

Background: Multiple sclerosis (MS) is a neurodegenerative disease caused by dysfunction of the immune system that affects the central nervous system (CNS). It is characterized by demyelination, chronic inflammation, neuronal and oligodendrocyte loss and reactive astrogliosis. It can result in physical disability and acute neurological and cognitive problems. Despite the gains in knowledge of immunology, cell biology, and genetics in the last five decades, the ultimate etiology or specific elements that trigger MS remain unknown. The objective of this review is to propose a theoretical basis for MS etiopathogenesis.Methods: Search was done by accessing PubMed/Medline, EBSCO, and PsycINFO databases. The search string used was "(multiple sclerosis* OR EAE) AND (pathophysiology* OR etiopathogenesis)". The electronic databases were searched for titles or abstracts containing these terms in all published articles between January 1, 1960, and June 30, 2019. The search was filtered down to 362 articles which were included in this review.Results: A framework to better understand the etiopathogenesis and pathophysiology of MS can be derived from four essential factors; mitochondria dysfunction (MtD) & oxidative stress (OS), vitamin D (VD), sex hormones and thyroid hormones. These factors play a direct role in MS etiopathogenesis and have a modulatory effect on many other factors involved in the disease.Conclusions: For better MS prevention and treatment outcomes, efforts should be geared towards treating thyroid problems, sex hormone alterations, VD deficiency, sleep problems and melatonin alterations. MS patients should be encouraged to engage in activities that boost total antioxidant capacity (TAC) including diet and regular exercise and discouraged from activities that promote OS including smoking and alcohol consumption.

B-cell related biomarkers associated with severity of the first demyelinating event of acute optic neuritis

BACKGROUND

Optic neuritis (ON) is the most common cause of acute unilateral visual loss in young adults and frequently occurs as the presenting symptom of multiple sclerosis (MS). Recently, we reported activation of peripheral blood CD19 + ‏ B-cells in the early stage of ON. In the current study we aimed to identify peripheral blood ‏B-cell molecular markers associated with ON severity and visual outcome.

METHODS

Expression of B-cell related biomarkers were analysed in patients with the first clinical presentation of acute unilateral ON. Logarithm of the Minimum Angle of Resolution (LogMAR). visual acuity, Optical Coherence Tomography (OCT) imaging, Expanded Disability Status Scale (EDSS) visual score and visual evoked responses were evaluated at onset and visual acuity and EDSS visual score were repeated at 6 months post-ON.

RESULTS

Thirty patients with acute unilateral ON, 77% female, mean age 33 ± 2.0 years, were enroled in the study. Expression of CD19, CD79A and CD20 B-cell markers significantly correlated with LogMAR visual acuity of the affected eye (r = 0.44, p = 0.01, r = 0.37, p = 0.01 and r = 0.36, p = 0.04, respectively). The marker levels were elevated between 1.5 and 2.2-folds in the group with worse visual acuity (LogMAR>1.0) at onset (CD79A:×1.5, p = 0.013; CD19:×2.25, p = 0.007; CD20:×1.5, p = 0.015) and not correlated with 6 month visual outcome.

CONCLUSIONS

Among patient with a first event of acute ON, expression of B-cell biomarkers correlated with the severity of the disease. These results could add information on the role of B-cell dysfunction in the early stages of ON.

TNFRSF13C/BAFFR P21R and H159Y polymorphisms in multiple sclerosis

Recent studies implicate B cells in multiple sclerosis (MS) pathogenesis, and consequently, several molecules participating in B cell survival and proliferation, including B-cell activating factor (BAFF), have recently been analyzed in MS patients. BAFF mediates its function through binding to three receptors; among them, its interaction with the BAFF receptor (BAFFR) is crucial in mediating its survival function. Interestingly, two common polymorphisms of the TNFRSF13C gene, encoding BAFFR, P21R (rs77874543) and H159Y (rs61756766), have been reported to affect BAFFR assembly and signaling. In order to evaluate the possible contribution of BAFFR in MS pathogenesis and/or phenotype, we analyzed both TNFRSF13C/BAFFR polymorphisms in 486 MS patients in relation to their disease severity, their disability status and the age of disease onset and duration. As control group, we used allele frequencies extracted from the Exome Aggregation Consortium (ExAC) Browser. Interestingly, we found a higher prevalence of the H159Y polymorphism in MS patients, suggesting that enhanced BAFFR-signaling might contribute to the disease pathogenesis.

Mesenchymal stromal cells attenuate multiple sclerosis via IDO-dependent increasing the suppressive proportion of CD5+ IL-10+ B cells

Multiple sclerosis (MS), one of the autoimmune and inflammatory diseases, is a major cause of neurological disability worldwide. The existing clinical treatments are not curable, and better treatments are urgently needed. Mesenchymal stromal cells (MSCs) have shown promise for treating MS, but the favorable effects and mechanism of MSC therapy on MS are still not fully understood. In this study, we analyzed the phenotypic feature of peripheral blood mononuclear cells (PBMCs) in MS patients and found that the patients exhibited an increase in the frequency of B cells, but a markedly decrease in frequency of CD5+ and IL-10+ B cells compared to healthy controls. Infusion of MSCs exhibited a significant therapeutic effect on the experimental autoimmune encephalomyelitis (EAE) mice, infiltration of mononuclear cells and demyelination of the spinal cords were both reduced in CNS of the mice, the frequency of CD5+ IL-10+ B cells in the mice was significantly increased. Additionally, when PBMCs or B cells from MS patients were co-cultured with MSCs, the frequency of CD5+ IL-10+ B cells also increased, the proliferative and immunosuppressive capacity of CD5+ B cells were significantly enhanced while the apoptosis ratio of this cellular subset significantly decreased. Moreover, those effects could be eliminated while the indoleamine 2,3-dioxygenase (IDO) inhibitor, D/L-1MT, was added to the co-cultured cells. In summary, this study suggests that MSCs can control EAE via IDO pathway to promote the proportion and function of CD5+ IL-10+ B cells, providing a promise to treat patients with MS in the clinical setting.

Behavioural phenotypes in the cuprizone model of central nervous system demyelination

The feeding of cuprizone (CPZ) to animals has been extensively used to model the processes of demyelination and remyelination, with many papers adopting a narrative linked to demyelinating conditions like multiple sclerosis (MS), the aetiology of which is unknown. However, no current animal model faithfully replicates the myriad of symptoms seen in the clinical condition of MS. CPZ ingestion causes mitochondrial and endoplasmic reticulum stress and subsequent apoptosis of oligodendrocytes leads to central nervous system demyelination and glial cell activation. Although there are a wide variety of behavioural tests available for characterizing the functional deficits in animal models of disease, including that of CPZ-induced deficits, they have focused on a narrow subset of outcomes such as motor performance, cognition, and anxiety. The literature has not been systematically reviewed in relation to these or other symptoms associated with clinical MS. This paper reviews these tests and makes recommendations as to which are the most important in order to better understand the role of this model in examining aspects of demyelinating diseases like MS.

Changes of B cell subsets in central pathological process of autoimmune encephalomyelitis in mice

Background

Multiple sclerosis is a demyelinating and autoimmune disease and its immune response is not fully elucidated. This study was conducted to examine the pathological changes and B cell subsets in experimental autoimmune encephalomyelitis (EAE) mice, and analyze the expression of triosephosphate isomerase (TPI) and GADPH to define the role of B cell subsets in the disease.

Results

Female C57BL/6 mice were randomly divided into EAE group (n = 18) and control (n = 18). During the experiments, the weight and nerve function scores were determined. The proportions of B cell subsets in the peripheral blood were measured by flow cytometry. Seven, 18 and 30 days after immunization, the brain and spinal cord tissues were examined for the infiltration of inflammatory cells using hematoxylin-eosin (HE) HE staining and the demyelination using Luxol fast blue staining. The expression of B cell-related proteins was detected immunohistochemistrially and the expression of antigenic TPI and GADPH was analyzed using enzyme-linked immunosorbent assay (ELISA). HE staining showed that mice had more severe EAE 18 d than 7 d after modelling, while the symptoms were significantly relieved at 30 d. The results were consistent with the weight measurements and neural function scores. Immunohistochemistry studies showed that B cells aggregated in the spinal cord, but not much in the brain. Flow cytometry studies showed that there were more B cells in control than in EAE models from day 7 and the difference was narrowed at day 30. The level of plasma cells increased continuously, reached the top at day 21 and obviously declined at day 30. On other hand, the numbers of memory B cells increased gradually over the experimental period. The numbers of plasma and memory B cells were similar between the control and EAE mice. ELISA data revealed that the brain contents of TPI and GAPDH were higher in EAE mice than in control at day 7, while at day 18, the levels were reversed.

Conclusions

In the central pathological process of EAE mice, B cells exert role through the mechanism other than producing antibodies and the levels of brain TPI and GADPH are related to the severity of autoimmune induced-damage.

Impact of B cells to the pathophysiology of multiple sclerosis

Introduction

Multiple sclerosis (MS) is a chronic autoimmune disorder that affects the central nervous system and compromises the health and well-being of millions of people worldwide. B cells have been linked to MS and its progression. This review aimed to determine the role of B cells in MS development.

Methods

Articles used in this review were obtained from PubMed, LILACS, and EBSCO. The search terms and phrases included “multiple sclerosis,” “MS,” “B-Cells,” “pathogenesis,” and “development.” Original research studies and articles on MS and B cells published between 2007 and 2018 were included.

Results

Results from the selected articles showed a significant connection between B cell groups and MS. B cells act as a significant source of plasma cells, which generate antibodies while also regulating autoimmune processes and T cell production. In addition, B cells regulate the release of molecules that affect the proinflammatory actions of other immune cells.

Discussion

B cells play key roles in immune system functioning and MS. The findings of this review illustrate the complex nature of B cell actions, their effects on the autoimmune system, and the method by which they contribute to MS pathogenesis.

Conclusion

Previous research implicates biological, genetic, and environmental factors in MS pathogenesis. This review suggests that B cells contribute to MS development and advancement by influencing and regulating autoimmune processes such as T cell production and APC activity.

Lower risk of multiple sclerosis in patients with chronic hepatitis C: a nationwide population-based registry study

Background

Multiple sclerosis (MS) is an immune-mediated neurological disease that causes demyelination. The etiology is unknown, but patients with a previous viral infection, such as Epstein–Barr virus, have been shown to be at a higher risk of developing MS. In contrast, people living with HIV have a lower risk of developing MS. Hepatitis C virus (HCV) mainly infects the liver, but patients with HCV can experience several extrahepatic manifestations and studies have shown an association with several autoimmune conditions such as neuropathy and myelitis. The present study aimed to investigate the risk of MS in patients with chronic HCV infection compared with matched comparators.

Methods

Patients were identified using the nationwide Swedish inpatient (2001–2013) and outpatient care registers (2001–2013) for HCV (B18.2) and MS (G35) according to the International Classification of Diseases-10. Up to five comparators (matched on age/sex/place of residency) were drawn from the general population for each HCV patient. Follow-up started at the first HCV visit from 2001 and the patients’ accrued person-time until death, emigration or 31 December 2013. Risk of MS diagnosis was calculated as standardized incidence ratio (SIR) with 95% confidence intervals (CIs).

Results

HCV patients were at lower risk of MS diagnosis (SIR 0.37; 95% CI 0.26–0.50). The incidence of MS during the study in the HCV cohort was 0.087% compared with 0.27% in the matched comparator cohort.

Conclusion

Surprisingly, these data suggest HCV patients to have a lower risk of MS diagnosis.

Electronic supplementary material

The online version of this article (10.1007/s00415-019-09397-8) contains supplementary material, which is available to authorized users.

Dimethyl fumarate, a two-edged drug: Current status and future directions

Dimethyl fumarate (DMF) is a fumaric acid ester registered for the treatment of relapsing-remitting multiple sclerosis (RRMS). It induces protein succination leading to inactivation of cysteine-rich proteins. It was first shown to possess cytoprotective and antioxidant effects in noncancer models, which appeared related to the induction of the nuclear factor erythroid 2 (NF-E2)-related factor 2 (NRF2) pathway. DMF also displays antitumor activity in several cellular and mice models. Recently, we showed that the anticancer mechanism of DMF is dose-dependent and is paradoxically related to the decrease in the nuclear translocation of NRF2. Some other studies performed indicate also the potential role of DMF in cancers, which are dependent on the NRF2 antioxidant and cellular detoxification program, such as KRAS-mutated lung adenocarcinoma. It, however, seems that DMF has multiple biological effects as it has been shown to also inhibit the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), thus blocking downstream targets that may be involved in the development and progression of inflammatory cascades leading to various disease processes, including tumors, lymphomas, diabetic retinopathy, arthritis, and psoriasis. Herein, we present the current status and future directions of the use of DMF in various diseases models with particular emphases on its targeting of specific intracellular signal transduction cascades in cancer; to shed some light on its possible mode of action.

Autoimmune Diseases and Psychotic Disorders

The notion of immunological pathways playing a role in the etiology of a subset of psychotic disorders has received increased interest in the last decades. One of the findings that has spiked interest herein, is an apparent link between autoimmune diseases and psychotic disorders. This is supported by genetic findings associating immune-related genetic markers with schizophrenia and clinical studies finding increased levels of inflammatory markers in patients with psychosis. Several large-scale epidemiologic studies have found positive associations between autoimmune diseases and psychosis. Particularly, autoimmune diseases as multiple sclerosis and lupus are known to have higher frequencies of neuropsychiatric symptoms, including psychosis, compared to healthy controls. Cross sectional studies have found higher prevalence of psychiatric diagnoses among those with autoimmune diseases, and longitudinal studies have shown bidirectional associations between several autoimmune diseases and increased risks associated with schizophrenia. Moreover, a family history of autoimmune diseases has been shown to be associated with an increased risk of psychotic disorders and vice versa. In this review we will summarize the epidemiologic evidence on associations between autoimmune diseases and psychosis. Possible mechanisms accountable for the association will be discussed, amongst others the probable role of shared genetic risk factors, the impact of infections on both autoimmunity and the development of psychotic disorders, and the potential role of the microbiome. We discuss the findings on and influence of autoantibodies and dysregulation of T- and B-cells in both disease categories, and why further research hereon is needed. In addition to the potential importance of autoimmunity in etiological mechanisms of psychotic disorders, the association also brings important attention to somatic comorbidity in patients with psychotic disorders.

Analysis of coding and non-coding transcriptome of peripheral B cells reveals an altered interferon response factor (IRF)-1 pathway in multiple sclerosis patients

Several evidences emphasize B-cell pathogenic roles in multiple sclerosis (MS). We performed transcriptome analyses on peripheral B cells from therapy-free patients and age/sex-matched controls. Down-regulation of two transcripts (interferon response factor 1-IRF1, and C-X-C motif chemokine 10-CXCL10), belonging to the same pathway, was validated by RT-PCR in 26 patients and 21 controls. IRF1 and CXCL10 transcripts share potential seeding sequences for hsa-miR-424, that resulted up-regulated in MS patients. We confirmed this interaction and its functional effect by transfection experiments. Consistent findings indicate down-regulation of IRF1/CXCL10 axis, that may plausibly contribute to a pro-survival status of B cells in MS.

Signaling pathways and therapeutic perspectives related to environmental factors associated with multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated demyelinating disorder of unknown etiology. Both genetic-susceptibility and environment exposures, including vitamin D deficiency, Epstein-Barr viral and Herpesvirus (HHV-6) infections are strongly implicated in the activation of T cells and MS-pathogenesis. Despite precise knowledge of how these factors could be operating alone or in combination to facilitate and aggravate the disease progression, it is clear that prolonged induction of inflammatory molecules and recruitment of other immune cells by the activated T cells results in demyelination and axonal damage. It is imperative to understand the risk factors associated with MS progression and how these factors contribute to disease pathology. Understanding of the underlying mechanisms of what factors triggers activation of T cells to attack myelin antigen are important to strategize therapeutics and therapies against MS. Current review provides a detailed literature to understand the role of both pathogenic and non-pathogenic factors on the impact of MS.

Expression Pattern of Myelin-Related Apolipoprotein D in Human Multiple Sclerosis Lesions

Apolipoprotein D (Apo D) is a key molecule in the lipid transport during homeostasis and repair processes in normal and pathological conditions of the nervous system with a putative neuroprotective effect. In the last decades, huge experimental efforts have been made to know the exact mechanism of action of Apo D, even though, it remains an open question. In this regard, studies in mammals and flies have suggested that Apo D seems to act through a variety of cellular mechanisms related with its ability to selectively bind different lipid ligands. For instance, this apolipoprotein is required to myelin compaction, it participates in axon regeneration/remyelination, and it can control the magnitude and timing of the inflammatory response after injury, promoting myelin clearance, and regulating the number of immune cells recruited to the damaged area. These, among others, are some of the reasons to study Apo D in multiple sclerosis (MS) pathology, where it could be particularly important since the autoimmune reaction against oligodendrocytes (OLGs) and myelin is generally assumed as the most plausible cause of this pathology. The aim of this work was to investigate the Apo D expression pattern in MS lesions, including active and inactive demyelinating plaques, and also remyelinating ones. Human brain tissues with inflammatory demyelination consistent with MS were used to quantify Apo D immunosignal in different lesions. Our results show a clear decrease of Apo D expression in all sclerosis plaques, being lower in the inactive than in active areas but recovers in the remyelination ones. Apo D is mainly produced by the matured OLGs of white matter and is located in cell processes surrounding the myelin sheath. All these data seem to indicate an important role of Apo D in myelination/remyelination processes as a molecule with a neuroprotective potential, and may serve as a good starting point for its study in MS.

Anti-CD52 antibody treatment depletes B cell aggregates in the central nervous system in a mouse model of multiple sclerosis

Background

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) for which several new treatment options were recently introduced. Among them is the monoclonal anti-CD52 antibody alemtuzumab that depletes mainly B cells and T cells in the immune periphery. Considering the ongoing controversy about the involvement of B cells and in particular the formation of B cell aggregates in the brains of progressive MS patients, an in-depth understanding of the effects of anti-CD52 antibody treatment on the B cell compartment in the CNS itself is desirable.

Methods

We used myelin basic protein (MBP)-proteolipid protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 (B6) mice as B cell-dependent model of MS. Mice were treated intraperitoneally either at the peak of EAE or at 60 days after onset with 200 μg murine anti-CD52 vs. IgG2a isotype control antibody for five consecutive days. Disease was subsequently monitored for 10 days. The antigen-specific B cell/antibody response was measured by ELISPOT and ELISA. Effects on CNS infiltration and B cell aggregation were determined by immunohistochemistry. Neurodegeneration was evaluated by Luxol Fast Blue, SMI-32, and Olig2/APC staining as well as by electron microscopy and phosphorylated heavy neurofilament serum ELISA.

Results

Treatment with anti-CD52 antibody attenuated EAE only when administered at the peak of disease. While there was no effect on the production of MP4-specific IgG, the treatment almost completely depleted CNS infiltrates and B cell aggregates even when given as late as 60 days after onset. On the ultrastructural level, we observed significantly less axonal damage in the spinal cord and cerebellum in chronic EAE after anti-CD52 treatment.

Conclusion

Anti-CD52 treatment abrogated B cell infiltration and disrupted existing B cell aggregates in the CNS.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1263-9) contains supplementary material, which is available to authorized users.