Association of serum Epstein–Barr nuclear antigen-1 antibodies and intrathecal immunoglobulin synthesis in early multiple sclerosis

Antibody Content against Epstein-Barr Virus in Blood Extracellular Vesicles Correlates with Disease Activity and Brain Volume in Patients with Relapsing-Remitting Multiple Sclerosis

We aimed to analyze whether EVs carry antibodies against EBV antigens and the possibility that they could serve as diagnostic and disease activity blood biomarkers in RRMS. This was a prospective and observational study including patients with RRMS with active and inactive disease and healthy controls. Blood EVs were isolated by precipitation. Titers of antibodies against nuclear (anti-EBNA1) and capsid (anti-VCA) EBV antigens in EVs and in plasma, as well as content of myelin antibodies in EVs were determined by ELISA. An exploratory analysis of correlations with clinical and radiological data was performed. Patients with RRMS had higher titers of anti-VCA inside EVs and free in plasma than healthy controls. Patients with active disease showed higher levels of anti-EBNA1 in EVs, but not in plasma, than patients with inactive disease. EV anti-VCA levels correlated with disease duration and with decreased brain volume structures-total brain, white matter, gray matter, cerebellum, hippocampus, -but not with T2/FLAIR lesion volume or EDSS, SDMT, or 9HPT. In addition, EV anti-VCA correlated with EV anti-MBP. The anti-VCA and anti-EBNA1 content in EVs could represent diagnostic and disease activity blood biomarkers, respectively, in RRMS.

Shared Pathogenicity Features and Sequences between EBV, SARS-CoV-2, and HLA Class I Molecule-binding Motifs with a Potential Role in Autoimmunity

Epstein-Barr virus (EBV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are extraordinary in their ability to activate autoimmunity as well as to induce diverse autoimmune diseases. Here we reviewed the current knowledge on their relation. Further, we suggested that molecular mimicry could be a possible common mechanism of autoimmunity induction in the susceptible individuals infected with SARS-CoV-2. Molecular mimicry between SARS-CoV-2 and human proteins, and EBV and human proteins, are present. Besides, relation of the pathogenicity associated with both coronavirus diseases and EBV supports the notion. As a proof-of-the-concept, we investigated 8mer sequences with shared 5mers of SARS-CoV-2, EBV, and human proteins, which were predicted as epitopes binding to the same human leukocyte antigen (HLA) supertype representatives. We identified significant number of human peptide sequences with predicted-affinities to the HLA-A*02:01 allele. Rest of the peptide sequences had predicted-affinities to the HLA-A*02:01, HLA-B*40:01, HLA-B*27:05, HLA-A*01:01, and HLA-B*39:01 alleles. Carriers of these serotypes can be under a higher risk of autoimmune response induction upon getting infected, through molecular mimicry-based mechanisms common to SARS-CoV-2 and EBV infections. We additionally reviewed established associations of the identified proteins with the EBV-related pathogenicity and with the autoimmune diseases.

Markers of Epstein-Barr Virus Infection in Patients with Multiple Sclerosis

Viral infections have been suspected of being involved in the pathogenesis of certain autoimmune diseases for many years. Epstein-Barr virus (EBV), a DNA virus belonging to the Herpesviridae family, is thought to be associated with the onset and/or the progression of multiple sclerosis (MS), systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome and type 1 diabetes. The lifecycle of EBV consists of lytic cycles and latency programmes (0, I, II and III) occurring in infected B-cells. During this lifecycle, viral proteins and miRNAs are produced. This review provides an overview of the detection of EBV infection, focusing on markers of latency and lytic phases in MS. In MS patients, the presence of latency proteins and antibodies has been associated with lesions and dysfunctions of the central nervous system (CNS). In addition, miRNAs, expressed during lytic and latency phases, may be detected in the CNS of MS patients. Lytic reactivations of EBV can occur in the CNS of patients as well, with the presence of lytic proteins and T-cells reacting to this protein in the CNS of MS patients. In conclusion, markers of EBV infection can be found in MS patients, which argues in favour of a relationship between EBV and MS.

Unstable EBV latency drives inflammation in multiple sclerosis patient derived spontaneous B cells

Epidemiological studies have demonstrated that Epstein-Barr virus (EBV) is a known etiologic risk factor, and perhaps prerequisite, for the development of MS. EBV establishes life-long latent infection in a subpopulation of memory B cells. Although the role of memory B cells in the pathobiology of MS is well established, studies characterizing EBV-associated mechanisms of B cell inflammation and disease pathogenesis in EBV (+) B cells from MS patients are limited. Accordingly, we analyzed spontaneous lymphoblastoid cell lines (SLCLs) from multiple sclerosis patients and healthy controls to study host-virus interactions in B cells, in the context of an individual's endogenous EBV. We identify differences in EBV gene expression and regulation of both viral and cellular genes in SLCLs. Our data suggest that EBV latency is dysregulated in MS SLCLs with increased lytic gene expression observed in MS patient B cells, especially those generated from samples obtained during "active" disease. Moreover, we show increased inflammatory gene expression and cytokine production in MS patient SLCLs and demonstrate that tenofovir alafenamide, an antiviral that targets EBV replication, decreases EBV viral loads, EBV lytic gene expression, and EBV-mediated inflammation in both SLCLs and in a mixed lymphocyte assay. Collectively, these data suggest that dysregulation of EBV latency in MS drives a pro-inflammatory, pathogenic phenotype in memory B cells and that this response can be attenuated by suppressing EBV lytic activation. This study provides further support for the development of antiviral agents that target EBV-infection for use in MS.

Human endogenous retrovirus and multiple sclerosis: A review and transcriptome findings

Multiple Sclerosis is an autoimmune disease with an unknown etiology. Both genetic and environmental factors are believed to trigger MS autoimmunity. Among the environmental factors, infectious agents have been extensively investigated, and the Human Endogenous Retroviruses (HERVs), especially HERV-W, are believed to be associated with MS pathogenesis. HERVs are derived from ancestral infections and comprise around 8% of the human genome. Although most HERVs are silenced, retroviral genes may be expressed with virion formation. There is extensive evidence of the relationship between HERV-W and MS, including higher levels of HERV-W expression in MS patients, HERV-W protein detection in MS plaques, and the HERV-W env protein inducing an inflammatory response in in vitro and in vivo models. Here we discuss possible links of HERVs and the pathogenesis of MS and present new data regarding the diversity of HERVs expression in samples derived from MS patients.

Intrathecal Antibody Production Against Epstein-Barr, Herpes Simplex, and Other Neurotropic Viruses in Autoimmune Encephalitis

Background and Objectives

Neurotropic viruses are suspected to play a role in the pathogenesis of autoimmune diseases of the CNS such as the association between the Epstein-Barr virus (EBV) and multiple sclerosis (MS). A group of autoimmune encephalitis (AE) is linked to antibodies against neuronal cell surface proteins. Because CNS infection with the herpes simplex virus can trigger anti–NMDA receptor (NMDAR) encephalitis, a similar mechanism for EBV and other neurotropic viruses could be postulated. To investigate for previous viral infections of the CNS, intrathecally produced virus-specific antibody synthesis was determined in patients with AE.

Methods

Antibody-specific indices (AIs) against EBV and measles, rubella, varicella zoster, herpes simplex virus, and cytomegalovirus were determined in 27 patients having AE (anti-NMDAR encephalitis, n = 21, and LGI1 encephalitis, n = 6) and in 2 control groups comprising of 30 patients with MS and 21 patients with noninflammatory CNS diseases (NIND), which were sex and age matched.

Results

An intrathecal synthesis of antibodies against EBV was found in 5/27 (19%) patients with AE and 2/30 (7%) of the patients with MS. All these patients had also at least 1 additional elevated virus-specific AI. In contrast, in none of the patients with NIND, an elevated virus-specific AI was detected.

Discussion

Intrathecally produced antibodies against EBV can be found in patients with AE and MS but only together with antibodies against different neurotropic viruses. Evidence of these antibodies is the result of a polyspecific immune response similar yet distinct from MS response rather than an elapsed infection of the CNS.

Epigenetic Plasticity Enables CNS-Trafficking of EBV-infected B Lymphocytes

Subpopulations of B-lymphocytes traffic to different sites and organs to provide diverse and tissue-specific functions. Here, we provide evidence that epigenetic differences confer a neuroinvasive phenotype. An EBV+ B cell lymphoma cell line (M14) with low frequency trafficking to the CNS was neuroadapted to generate a highly neuroinvasive B-cell population (MUN14). MUN14 B cells efficiently infiltrated the CNS within one week and produced neurological pathologies. We compared the gene expression profiles of viral and cellular genes using RNA-Seq and identified one viral (EBNA1) and several cellular gene candidates, including secreted phosphoprotein 1/osteopontin (SPP1/OPN), neuron navigator 3 (NAV3), CXCR4, and germinal center-associated signaling and motility protein (GCSAM) that were selectively upregulated in MUN14. ATAC-Seq and ChIP-qPCR revealed that these gene expression changes correlated with epigenetic changes at gene regulatory elements. The neuroinvasive phenotype could be attenuated with a neutralizing antibody to OPN, confirming the functional role of this protein in trafficking EBV+ B cells to the CNS. These studies indicate that B-cell trafficking to the CNS can be acquired by epigenetic adaptations and provide a new model to study B-cell neuroinvasion associated CNS lymphoma and autoimmune disease of the CNS, including multiple sclerosis (MS).

The role of Epstein-Barr virus in the etiology of multiple sclerosis: a current review

Introduction: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. While its exact etiology is unknown, it is generally believed that MS is caused by environmental triggers in genetically predisposed individuals. Strong and consistent evidence suggests a key role of Epstein-Barr virus (EBV), a B lymphotropic human gammaherpesvirus, in the etiology of MS. Areas covered: This review summarizes recent developments in the field of EBV and MS with a focus on potential mechanisms underlying the role of EBV in MS. PubMed was searched for the terms 'Epstein-Barr virus' and 'multiple sclerosis'. Expert opinion: The current evidence is compatible with the working hypothesis that MS is a rare complication of EBV infection. Under the premise of a causative role of EBV in MS, it needs to be postulated that EBV causes a specific, and likely persistent, change(s) that is necessarily required for the development of MS. However, although progress has been made, the nature of that change and thus the precise mechanism explaining the role of EBV in MS remain elusive. The mechanism of EBV in MS therefore is a pressing question, whose clarification may substantially advance the pathophysiological understanding, rational therapies, and prevention of MS.

Epstein-Barr Virus Infection in the Development of Neurological Disorders

Epstein-Barr Virus (EBV) is a ubiquitous human herpesvirus that contributes to the etiology of diverse human cancers and auto-immune diseases. EBV establishes a relatively benign, long-term latent infection in over 90 percent of the adult population. Yet, it also increases risk for certain cancers and auto-immune disorders depending on complex viral, host, and environmental factors that are only partly understood. EBV latent infection is found predominantly in memory B-cells, but the natural infection cycle and pathological aberrations enable EBV to infect numerous other cell types, including oral, nasopharyngeal, and gastric epithelia, B-, T-, and NK-lymphoid cells, myocytes, adipocytes, astrocytes, and neurons. EBV infected cells, free virus, and gene products can also be found in the CNS. In addition to the direct effects of EBV on infected cells and tissue, the effect of chronic EBV infection on the immune system is also thought to contribute to pathogenesis, especially auto-immune disease. Here, we review properties of EBV infection that may shed light on its potential pathogenic role in neurological disorders.

Ozanimod for the treatment of relapsing remitting multiple sclerosis

INTRODUCTION

Ozanimod is a selective sphingosine 1-phosphate receptor 1 and 5 modulator under development by Celgene, for the treatment of relapsing remitting multiple sclerosis. Extensive clinical experience has become available for the related compound fingolimod, favoring the sphingosine 1-phosphate therapeutic concept. Off-target effects have been attributed to its low receptor specificity and have prompted the development of next generation sphingosine 1-phosphate receptor modulators. Areas covered: The authors evaluate the literature of ozanimod, using the PubMed database as well as repositories of the European Committee for Treatment and Research in Multiple Sclerosis and the American and European Academy of Neurology. Specifically, the authors cover and discuss the preclinical data on ozanimod, pharmacokinetics and dynamics, and data on efficacy and safety from the pivotal trials. Expert opinion: Superiority of ozanimod over intramuscular interferon β-1a with regard to reduction in annualized relapse rate and magnetic resonance imaging outcomes has been shown in two phase III trials. The beneficial effect on brain volume and gray matter loss are encouraging and in line with data on other newer immunomodulators. Ozanimod is a valuable contribution to the therapeutic armamentarium in MS, although the effect on disability progression is unclear and requires further investigations.

Low intrathecal antibody production despite high seroprevalence of Epstein-Barr virus in multiple sclerosis: a review of the literature

BACKGROUND

Patients with multiple sclerosis (MS) frequently have an intrathecal production of antibodies to different common viruses, which can be detected by elevated antiviral antibody indices (AIs). There is a strong and consistent association of MS and Epstein-Barr virus (EBV) infection.

OBJECTIVE

To systematically compare the frequencies of intrathecal antibody production to EBV, measles virus, rubella virus, varicella zoster virus (VZV) and herpes simplex virus (HSV) in patients with MS.

METHODS

Review of the English and German literature on the frequencies of intrathecal immunoglobulin (Ig)G antibody production, as defined by an elevated AI, to EBV, measles virus, rubella virus, VZV and HSV in adult and pediatric patients with MS.

RESULTS

In nine original studies identified, the frequencies of an intrathecal production of antibodies to Epstein-Barr nuclear antigen-1 (33/340, 9.7%), EBV viral capsid antigen (12/279, 4.3%) and antigens from EBV-infected cell lines (14/90, 15.6%) in adult patients with MS were clearly lower (p ≤ 0.03 for all pairwise comparisons) than the frequencies of an intrathecal production of antibodies to measles virus (612/922, 66.4%), rubella virus (521/922, 56.5%), VZV (470/922, 51%; data from 17 original studies) and HSV (78/291, 26.8%; data from 6 original studies). Though based on a lower number of original studies and patients, findings in children with MS were essentially similar. As in adults and children with MS the seroprevalence of EBV is higher than the seroprevalences of the other investigated viruses, the lower frequency of elevated EBV AIs became even more pronounced after correction of the frequencies of elevated antiviral AIs for the seroprevalences of the respective viruses.

CONCLUSIONS

Given the very high seroprevalence of EBV in MS, the frequency of intrathecally produced antibodies to EBV in patients with MS is paradoxically low compared to that of other common viruses. These findings are compatible with the recently proposed hypothesis that in individuals going on to develop MS antiviral antibody-producing cells may invade the brain predominantly at the time of and triggered by acute primary EBV infection, before anti-EBV IgG producing cells have yet occurred.

How compelling are the data for Epstein-Barr virus being a trigger for systemic lupus and other autoimmune diseases?

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is caused by a combination of genetic and acquired immunodeficiencies and environmental factors including infections. An association with Epstein-Barr virus (EBV) has been established by numerous studies over the past decades. Here, we review recent experimental studies on EBV, and present our integrated theory of SLE development.

RECENT FINDINGS

SLE patients have dysfunctional control of EBV infection resulting in frequent reactivations and disease progression. These comprise impaired functions of EBV-specific T-cells with an inverse correlation to disease activity and elevated serum levels of antibodies against lytic cycle EBV antigens. The presence of EBV proteins in renal tissue from SLE patients with nephritis suggests direct involvement of EBV in SLE development. As expected for patients with immunodeficiencies, studies reveal that SLE patients show dysfunctional responses to other viruses as well. An association with EBV infection has also been demonstrated for other autoimmune diseases, including Sjögren's syndrome, rheumatoid arthritis, and multiple sclerosis.

SUMMARY

Collectively, the interplay between an impaired immune system and the cumulative effects of EBV and other viruses results in frequent reactivation of EBV and enhanced cell death, causing development of SLE and concomitant autoreactivities.

Multiple sclerosis: an example of pathogenic viral interaction?

A hypothesis is formulated on viral interaction between HHV-6A and EBV as a pathogenic mechanism in Multiple Sclerosis (MS). Evidence of molecular and genetic mechanisms suggests a link between HHV-6A infection and EBV activation in the brain of MS patients leading to intrathecal B-cell transformation. Consequent T-cell immune response against the EBV-infected cells is postulated as a pathogenic basis for inflammatory lesion formation in the brain of susceptible individuals. A further link between HHV-6A and EBV involves their induction of expression of the human endogenous retrovirus HERV-K18-encoded superantigen. Such virally induced T-cell responses might secondarily also lead to local autoimmune phenomena. Finally, research recommendations are formulated for substantiating the hypothesis on several levels: epidemiologically, genetically, and viral expression in the brain.

Antibody producing B lineage cells invade the central nervous system predominantly at the time of and triggered by acute Epstein-Barr virus infection: A hypothesis on the origin of intrathecal immunoglobulin synthesis in multiple sclerosis

Patients with multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system (CNS), typically have an intrathecal synthesis of immunoglobulin (Ig)G. Intrathecal IgG is produced by B lineage cells that entered the CNS, but why and when these cells invade the CNS of patients with MS is unknown. The intrathecal IgG response in patients with MS is polyspecific and part of it is directed against different common viruses (e.g. measles virus, rubella virus, varicella zoster virus). Strong and consistent evidence suggests an association of MS and Epstein-Barr virus (EBV) infection and EBV seroprevalence in patients with MS is practically 100%. However, intriguingly, despite of the universal EBV seroprevalence, the frequency of intrathecally produced IgG to EBV in patients with MS is much lower than that of intrathecally produced IgG to other common viruses. The acute phase of primary EBV infection is characterized by a strong polyclonal B cell activation. As typical for humoral immune responses against viruses, EBV specific IgG is produced only with a temporal delay after acute EBV infection. Aiming to put the above facts into a logical structure, we here propose the hypothesis that in individuals going on to develop MS antibody producing B lineage cells invade the CNS predominantly at the time of and triggered by acute primary EBV infection. Because at the time of acute EBV infection EBV IgG producing B lineage cells have not yet occurred, the hypothesis could explain the universal EBV seroprevalence and the low frequency of intrathecally produced IgG to EBV in patients with MS. Evidence supporting the hypothesis could be provided by large prospective follow-up studies of individuals with symptomatic primary EBV infection (infectious mononucleosis). Furthermore, the clarification of the molecular mechanism underlying an EBV induced invasion of B lineage cells into the CNS of individuals going on to develop MS could corroborate it, too. If true, our hypothesis would link EBV infection, the most important environmental risk factor for MS, with intrathecal IgG synthesis, the most characteristic laboratory feature of MS. Besides explaining the origin of intrathecal IgG synthesis in patients with MS, the hypothesis could thus also provide a conceptual framework for clarifying the mechanism through which EBV contributes to the development of MS.

Virus-Induced Demyelination: The Case for Virus(es) in Multiple Sclerosis

Multiple Sclerosis (MS) is the most common demyelinating disease of man with over 400,000 cases in the United States and over 2.5 million cases worldwide. There are over 64,000 citations in Pubmed dating back as far as 1887. Much has been learned over the past 129 years with a recent burst in therapeutic options (mostly anti-inflammatory) with newer medications in development that are neuroprotective and/or neuroreparative. However, with all these advancements the cause of MS remains elusive. There is a clear interplay of genetic, immunologic, and environmental factors that influences both the development and progression of this disorder. This chapter will give a brief overview of the history and pathogenesis of MS with attention to how host immune responses in genetically susceptible individuals contribute to the MS disease process. In addition, we will explore the role of infectious agents in MS as potential “triggers” of disease. Models of virus-induced demyelination will be discussed, with an emphasis on the recent interest in human herpesviruses and the role they may play in MS disease pathogenesis. Although we remain circumspect as to the role of any microbial pathogen in MS, we suggest that only through well-controlled serological, cellular immune, molecular, and animal studies we will be able to identify candidate agents. Ultimately, clinical interventional trials that either target a specific pathogen or class of pathogens will be required to make definitive links between the suspected agent and MS.