Longitudinal analysis reveals high prevalence of Epstein-Barr virus associated with multiple sclerosis

Lysate of Parabacteroides distasonis prevents severe forms of experimental autoimmune encephalomyelitis by modulating the priming of T cell response

The gut microbiota influences the reactivity of the immune system, and Parabacteroides distasonis has emerged as an anti-inflammatory commensal. Here, we investigated whether its lysate could prevent severe forms of neuroinflammation in experimental autoimmune encephalomyelitis (EAE) in mice and how this preventive strategy affects the gut microbiota and immune response. Lysate of anaerobically cultured P. distasonis (Pd lysate) was orally administered to C57BL/6 mice in four weekly doses. One week later, EAE was induced and disease severity was assessed three weeks after induction. Fecal microbiota changes in both vehicle- and Pd lysate-treated animals was analyzed by 16S V3-V4 amplicon sequencing and qPCR, antimicrobial peptide expression in the intestinal mucosa was measured by qPCR, and immune cell composition in the mesenteric and inguinal lymph nodes was measured by multicolor flow cytometry. Pd lysate significantly delayed the development of EAE and reduced its severity when administered prior to disease induction. EAE induction was the main factor in altering the gut microbiota, decreasing the abundance of lactobacilli and segmented filamentous bacteria. Pd lysate significantly increased the intestinal abundance of the genera Anaerostipes, Parabacteroides and Prevotella, and altered the expression of antimicrobial peptides in the intestinal mucosa. It significantly increased the frequency of regulatory T cells, induced an anti-inflammatory milieu in mesenteric lymph nodes, and reduced the activation of T cells at the priming site. Pd lysate prevents severe forms of EAE by triggering a T regulatory response and modulating T cell priming to autoantigens. Pd lysate could thus be a future modulator of neuroinflammation that increases the resistance to multiple sclerosis.

Prophylactic administration of PEPITEM in experimental autoimmune encephalomyelitis delays disease onset, inhibits leukocyte infiltration, and alleviates severity

BACKGROUND

Multiple sclerosis (MS) is a chronic, immune-mediated neurological disorder in which the immune system mistakenly attacks the myelin sheath, affecting the communication between the brain and the rest of the body.

OBJECTIVE

This study investigated the prophylactic use of peptide inhibitor of trans-endothelial migration (PEPITEM), a novel peptide, in alleviating experimental autoimmune encephalomyelitis (EAE), a mouse model for Multiple Sclerosis (MS).

METHODS

Female C57BL/6 female mice were assigned to the control, untreated EAE, or PEPITEM group. EAE was induced in mice in the untreated EAE and PEPITEM groups through immunization by injecting an emulsion containing myelin oligodendrocyte glycoprotein 35-55 in complete Freund's adjuvant. Mice in these groups subsequently received PEPITEM or scramble peptide injections daily for 21 days. Then, all mice were euthanized to obtain samples for histologic and immunohistochemical analyses of central nervous system lymphocytic infiltrate. Levels of biomarkers, including myelin basic protein, microtubule-associated protein 2 (MAP-2), interleukin-17 (IL-17), and forkhead box P3 (Foxp3), were evaluated in both serum and spinal cord lysates using western blotting and enzyme-linked immunosorbent assay.

RESULTS

In the PEPITEM group, EAE onset was significantly delayed and disease severity was reduced compared to the untreated EAE group. Analysis of spinal cord tissues revealed a marked reduction in inflammatory cell infiltration following PEPITEM administration. Furthermore, PEPITEM treatment led to significantly reduced IL-17 and Foxp3 levels, highlighting its potential in mitigating inflammatory responses.

CONCLUSION

PEPITEM has potent prophylactic potential against MS, providing a robust foundation for further exploration.

Sp140L Is a Novel Herpesvirus Restriction Factor

Herpesviruses, including the oncogenic Epstein-Barr Virus (EBV), must bypass host DNA sensing mechanisms to establish infection. The first viral latency protein expressed, EBNA-LP, is essential for transformation of naïve B cells, yet its role in evading host defenses remains unclear. Using single-cell RNA sequencing of EBNA-LP-Knockout (LPKO)-infected B cells, we reveal an antiviral response landscape implicating the 'speckled proteins' as key restriction factors countered by EBNA-LP. Specifically, loss of SP100 or the primate-specific SP140L reverses the restriction of LPKO, suppresses a subset of canonically interferon-stimulated genes, and restores viral gene transcription and cellular proliferation. Notably, we also identify Sp140L as a restriction target of the herpesvirus saimiri ORF3 protein, implying a role in immunity to other DNA viruses. This study reveals Sp140L as a restriction factor that we propose links sensing and transcriptional suppression of viral DNA to an IFN-independent innate immune response, likely relevant to all nuclear DNA viruses.

Increased EBNA1-specific antibody response in primary-progressive multiple sclerosis

BACKGROUND AND OBJECTIVES

The impact of viral infections on disease susceptibility and progression has predominantly been studied in patients with relapse-onset MS (RMS). Here, we determined immune responses to ubiquitous viruses in patients with primary progressive MS (PPMS).

METHODS

Antibody responses to Epstein-Barr virus (EBV), specifically to the latent EBV nuclear antigen 1 and the lytic viral capsid antigen VCA, human herpesvirus 6 (HHV-6), human cytomegalovirus (HCMV), and measles virus were determined in a cohort of 68 PPMS patients with a mean follow-up of 8 years and compared with 66 healthy controls matched for sex and age.

RESULTS

Compared with controls, PPMS patients showed increased humoral immune responses to the EBV-encoded nuclear antigen-1 (EBNA1), but not to the lytic EBV capsid antigen (VCA) or to other viral antigens. Seroprevalence rates for HCMV were significantly higher in PPMS. Antiviral immune responses at baseline did not correlate with disability progression over time.

DISCUSSION

Elevated immune responses toward EBNA1 are selectively increased in people with primary progressive disease, indicating a link between EBNA1-targeting immune responses and the development of both RMS and PPMS. Our data also suggest that chronic HCMV infection is associated with progressive MS.

MMPred: a tool to predict peptide mimicry events in MHC class II recognition

We present MMPred, a software tool that integrates epitope prediction and sequence alignment algorithms to streamline the computational analysis of molecular mimicry events in autoimmune diseases. Starting with two protein or peptide sets (e.g., from human and SARS-CoV-2), MMPred facilitates the generation, investigation, and testing of mimicry hypotheses by providing epitope predictions specifically for MHC class II alleles, which are frequently implicated in autoimmunity. However, the tool is easily extendable to MHC class I predictions by incorporating pre-trained models from CNN-PepPred and NetMHCpan. To evaluate MMPred's ability to produce biologically meaningful insights, we conducted a comprehensive assessment involving i) predicting associations between known HLA class II human autoepitopes and microbial-peptide mimicry, ii) interpreting these predictions within a systems biology framework to identify potential functional links between the predicted autoantigens and pathophysiological pathways related to autoimmune diseases, and iii) analyzing illustrative cases in the context of SARS-CoV-2 infection and autoimmunity. MMPred code and user guide are made freely available at https://github.com/ComputBiol-IBB/MMPRED.

Senolytic Vaccines from the Central and Peripheral Tolerance Perspective

Preventive medicine has proven its long-term effectiveness and economic feasibility. Over the last century, vaccination has saved more lives than any other medical technology. At present, preventative measures against most infectious diseases are successfully used worldwide; in addition, vaccination platforms against oncological and even autoimmune diseases are being actively developed. At the same time, the development of medicine led to an increase in both life expectancy and the proportion of age-associated diseases, which pose a heavy socio-economic burden. In this context, the development of vaccine-based approaches for the prevention or treatment of age-related diseases opens up broad prospects for extending the period of active longevity and has high economic potential. It is well known that the development of age-related diseases is associated with the accumulation of senescent cells in various organs and tissues. It has been demonstrated that the elimination of such cells leads to the restoration of functions, rejuvenation, and extension of the lives of experimental animals. However, the development of vaccines against senescent cells is complicated by their antigenic heterogeneity and the lack of a unique marker. In addition, senescent cells are the body's own cells, which may be the reason for their low immunogenicity. This mini-review discusses the mechanisms of central and peripheral tolerance that may influence the formation of an anti-senescent immune response and be responsible for the accumulation of senescent cells with age.

Comparative efficacy and tolerability of ublituximab vs. other monoclonal antibodies in the treatment of relapsing multiple sclerosis: a systematic review and network meta-analysis of randomized trials

Background

Relapsing multiple sclerosis (RMS) is a chronic, inflammatory disease of the central nervous system. Ublituximab, an anti-CD20 monoclonal antibody (mAb), is indicated for the treatment of RMS. We performed a systematic literature review (SLR) to identify randomized trials reporting the clinical efficacy and tolerability of ublituximab or comparator disease-modifying therapies (DMTs) for treatment of RMS, and assessed their comparative effects using network meta-analysis (NMA).

Methods

The SLR involved a comprehensive search across various medical databases to identify relevant studies. Included studies were randomized controlled trials (RCTs) of an adult RMS population, focusing on treatment with at least one of ublituximab, alemtuzumab, natalizumab, ocrelizumab, or ofatumumab. For outcomes included in the NMA (annualized relapse rate (ARR), confirmed disability progression (CDP), and treatment discontinuation rate), rate ratios (RR) or hazard ratios (HR), along with their 95% confidence intervals (CIs), were calculated. We performed NMA using a contrast-based random-effects model within a frequentist framework for all outcomes. Ranking probabilities among comparators, and intervention rankings for the NMA, were estimated using surface under the cumulative ranking curve (SUCRA).

Results

We included 15 RCTs in the review. For the ARR outcome, there was no statistically significant difference between ublituximab and the other included mAbs [ofatumumab (RR 1.02 (95% CI 0.64-1.62)), natalizumab (RR 0.99 (0.59-1.65)), alemtuzumab (RR 0.86 (0.51-1.46)), and ocrelizumab (RR 0.75 (0.44-1.28))]. For CDP at 6 months, our results showed no statistically significant difference between ublituximab and the comparator mAbs [ofatumumab (HR 0.97 (0.49-1.92)), natalizumab (HR 1.13 (0.53-2.40)), alemtuzumab (HR 1.25 (0.56-2.81)), and ocrelizumab (HR 1.29 (0.57-2.90))]. For CDP at 3 and 6 months, there was no statistically significant difference between ublituximab and placebo. The all-cause treatment discontinuation rate analysis showed no significant difference between ublituximab and other mAbs, except for alemtuzumab.

Conclusions

Results of this SLR-informed NMA showed that there is no statistically significant difference between ublituximab and the other mAbs in terms of clinical efficacy. Additionally, the findings show that there is no statistically significant difference in discontinuation rates with the exception of the comparison with alemtuzumab, which may be attributed to its unique dosing schedule.

Elucidating the causal nexus between antibody-mediated immunity and autoimmune diseases: Insights from bidirectional mendelian randomization, gene expression profiling, and drug sensitivity analysis

OBJECTIVE

This study aimed to elucidate the causal relationships between antibodies and autoimmune diseases using Mendelian randomization (MR).

METHODS

Data on 46 antibodies were obtained from genome-wide association studies (GWAS). Autoimmune disease data were sourced from the FinnGen consortium and the IEU OpenGWAS project. Inverse-variance weighted (IVW) analysis was the primary method, supplemented by heterogeneity and sensitivity analyses. We also examined gene expression near significant SNPs and conducted drug sensitivity analyses.

RESULTS

Antibodies and autoimmune diseases exhibit diverse interactions. Antibodies produced after Polyomavirus infection tend to increase the risk of several autoimmune diseases, while those following Human herpesvirus 6 infection generally reduce it. The impact of Helicobacter pylori infection varies, with different antibodies affecting autoimmune diseases in distinct ways. Overall, antibodies significantly influence the risk of developing autoimmune diseases, whereas autoimmune diseases have a lesser impact on antibody levels. Gene expression and drug sensitivity analyses identified multiple genes and drugs as potential treatment options for ankylosing spondylitis (AS), with the AIF1 gene being particularly promising.

CONCLUSIONS

Bidirectional MR analysis confirms complex causal relationships between various antibodies and autoimmune diseases, revealing intricate patterns of post-infection antibody interactions. Several drugs and genes, notably AIF1, show potential as candidates for AS treatment, offering new avenues for research. Further exploration of the underlying mechanisms is necessary.

HLA-transgenic mouse models to study autoimmune central nervous system diseases

It is known that certain human leukocyte antigen (HLA) genes are associated with autoimmune central nervous system (CNS) diseases, such as multiple sclerosis (MS), but their exact role in disease susceptibility and etiopathogenesis remains unclear. The best studied HLA-associated autoimmune CNS disease is MS, and thus will be the primary focus of this review. Other HLA-associated autoimmune CNS diseases, such as autoimmune encephalitis and neuromyelitis optica will be discussed. The lack of animal models to accurately capture the complex human autoimmune response remains a major challenge. HLA transgenic (tg) mice provide researchers with powerful tools to investigate the underlying mechanisms promoting susceptibility and progression of HLA-associated autoimmune CNS diseases, as well as for elucidating the myelin epitopes potentially targeted by T cells in autoimmune disease patients. We will discuss the potential role(s) of autoimmune disease-associated HLA alleles in autoimmune CNS diseases and highlight information provided by studies using HLA tg mice to investigate the underlying pathological mechanisms and opportunities to use these models for development of novel therapies.

Hidden liver-joint axis: HBV infection causes rheumatoid arthritis via TRAFD1 with imbalance of HBV X protein and trans-ferulic acid

Liver metabolites are involved in the progression of rheumatoid arthritis (RA), indicating a connection between the liver and joints. However, the impact and mechanism of Hepatitis B virus (HBV), a hepatotropic virus, on RA are still unclear. We investigated the correlation between HBV and RA using Mendelian randomization analysis. Single-cell transcriptome analysis was conducted to investigate changes in cell subtypes in synovial tissue of HBV-RA patients. Fibroblast-like synoviocytes (FLS) were used to create a cell model, and the transcriptome was examined to identify the key downstream molecules of FMT regulated by HBx. CIA model was constructed using HBV transgenic, HBx transgenic, and TRADF1 knockout mice to investigate the impact and mechanism of HBV on CIA. The results of our study revealed a significant positive correlation between HBV and RA. The functional studies identified a crucial role of fibroblast-myofibroblast transition (FMT) in the progression of RA. The results suggest that HBV-encoded HBx may promote FMT in RA by upregulating TRAFD1. Furthermore, trans-ferulic acid (TFA) was identified by screening for common metabolites in the liver, joints, and peripheral blood using the metabolome and WGCNA. Interestingly, we found that TFA ameliorated HBx-induced RA by suppressing TRAFD1 expression. Our study demonstrates that hidden liver-joint axis, an imbalance between TFA and HBx, plays a critical role in HBV-induced RA, which could be a potential strategy for preventing RA development.

Greater humoral EBV response may be associated with choroid plexus inflammation in progressive MS

Choroid plexus (CP) inflammation can be quantified in vivo with MRI in people with multiple sclerosis (pwMS). It remains unknown whether Epstein Barr Virus (EBV) is related to CP changes. Total of 170 pwMS (116 relapsing-remitting; RRMS and 54 progressive MS; PMS) underwent MRI examination and measurement of humoral anti-EBV response. CP volume and CP pseudo-T2 (pT2), a relaxation time indicative of edema and neuroinflammation, were measured. Moreover, anti-EBV nuclear antigen-1 (EBNA-1) IgG and anti-EBV capsid antigen (VCA) IgG antibodies were measured. The PMS group had greater CP pT2 value when compared to RRMS (1120ms vs. 954ms, p = 0.037). After adjusting for age and therapy effects, higher CP pT2 values were associated with higher anti-EBNA-1 IgG levels only in PMS (r = 0.352, p = 0.015). Higher Anti-EBV humoral response in pwMS may be associated with increased CP neuroinflammatory changes and may be more relevant for the later chronic stage of the disease. Large-scale studies should investigate whether these findings are generalizable to all types of progressive MS.

Herpesvirus Antibodies Are Correlated With Greater Expression of p16 in the T Cells of Humans

Background

There is an increasing awareness that aging of the immune system, or immunosenescence, is a key biological process underlying many of the hallmark diseases of aging and age-related decline broadly. While immunosenescence can be in part due to normal age-related changes in the immune system, emerging evidence posits that viral infections may be biological stressors of the immune system that accelerate the pace of immunosenescence.

Methods

We used a convenience sample of 42 individuals aged 65 years and older to examine correlations between antiviral immunoglobulin G (IgG) levels for 4 human herpesviruses (cytomegalovirus [CMV], herpes simplex virus [types 1 and 2], and Epstein-Barr virus) and multiple indicators of T-cell immunosenescence.

Results

We found that most of the sample (n = 33) was antiviral IgG positive for 2 or more of the 4 herpesvirus infections. We also examined correlations between both the total number of viruses for which an individual had antiviral IgG and each individual virus and multiple indicators of T-cell immunosenescence, particularly p16 expression. The strongest correlations were observed between the total number of viruses for which an individual had detectable antiviral IgG and p16 mean fluorescent intensity (MFI) among CD27-CD28-CD57+ CD4+ cells (r = 0.60; P < .001) and between anti-CMV IgG and p16 MFI of CD27-CD57+ CD4+ cells (r = 0.59; P < .001).

Conclusions

Broadly, our findings offer compelling preliminary evidence for future investigations to incorporate multiple indicators of persistent viral infections and a more comprehensive set of markers of T-cell immunosenescence in population-based studies of aging.

Alarm Functions of PD-1+ Brain-Resident Memory T Cells

Resident memory T cells (TRM cells) have been described in barrier tissues as having a "sensing and alarm" function where, upon sensing cognate Ag, they alarm the surrounding tissue and orchestrate local recruitment and activation of immune cells. In the immunologically unique and tightly restricted CNS, it remains unclear whether and how brain TRM cells, which express the inhibitory receptor programmed cell death protein 1 (PD-1), alarm the surrounding tissue during Ag re-encounter. Using mouse models, we reveal that TRM cells are sufficient to drive the rapid remodeling of the brain immune landscape through activation of microglia, dendritic cells, NK cells, and B cells, expansion of regulatory T cells, and recruitment of macrophages and monocytic dendritic cells. Moreover, we report that although PD-1 restrained granzyme B upregulation in brain TRM cells reactivated via viral peptide, we observed no apparent effect on cytotoxicity in vivo, or downstream alarm responses within 48 h of TRM reactivation. We conclude that TRM cells are sufficient to trigger rapid immune activation and recruitment in the CNS and may have an unappreciated role in driving neuroinflammation.

Microglial Mayhem NLRP3 Inflammasome's Role in Multiple Sclerosis Pathology

INTRODUCTION

This review delves into the intricate relationship between NLR inflammasomes, particularly the NLRP3 inflammasome, and the immune-mediated neurodegenerative disease, multiple sclerosis (MS). While the precise etiology of MS remains elusive, compelling research underscores the pivotal role of the immune response in disease progression. Notably, recent investigations highlight the significant involvement of NLRP3 inflammasomes in various autoimmune diseases, prompting an in-depth exploration of their impact on MS.

METHOD

The review focuses on elucidating the activation mechanism of NLRP3 inflammasomes within microglia/macrophages (MG/MФ), examining how this activation promotes an inflammatory response that exacerbates neuronal damage in MS. A comprehensive analysis of existing literature and research findings forms the basis for understanding the intricate interplay between NLRP3 inflammasomes and MS pathogenesis.

RESULTS

Synthesizing current research, the review provides insight into the pivotal role played by NLR inflammasomes, specifically NLRP3, in MS. Emphasis is placed on the inflammatory response orchestrated by activated MG/MФ, elucidating the cascade that perpetuates neuronal damage in the disease.

CONCLUSIONS

This review concludes by consolidating key findings and offering a nuanced perspective on the role of NLRP3 inflammasomes in MS pathogenesis. The detailed exploration of the activation process within MG/MФ provides a foundation for understanding the disease's underlying mechanisms. Furthermore, the review sets the stage for potential therapeutic strategies targeting NLRP3 inflammasomes in the pursuit of MS treatment.

Epstein-Barr nuclear antigen 1 antibody-based indices are increased in patients with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic central nervous system (CNS) disease, which is diagnosed by a combination of clinical symptoms and magnetic resonance imaging and measurement of an increased intrathecal antibody synthesis. Genetic as well as environmental factors influence onset of the disease, where especially Epstein-Barr virus (EBV) infection is directly involved in MS development. In this open retrospective study, we aimed to elaborate whether various serum and cerebrospinal fluid (CSF)-based EBV antibody indices may aid in the diagnosis of MS.

METHODS

Epstein-Barr nuclear antigen (EBNA)1 IgG concentrations in serum and CSF of relapsing-remitting (RR)MS patients (n=61) (M:F 28:33, average 40 years), optic neuritis patients (n=26) (M:F 9:17, average 47 years) and healthy controls (HCs) (n=15) (M:F 8:7, average 43 years) were determined by enzyme-linked immunosorbent assay. The obtained EBNA1 IgG levels were compared to factors such as total IgG, albumin concentrations, specific antibody index, and various serum- and CSF-based indices.

RESULTS

Significantly elevated EBNA1 IgG levels were detected in serum and CSF of RRMS patients compared to HCs. CSF EBNA1 IgG and indices based on specific CSF EBNA1 IgG associated with CSF albumin or serum EBNA1 IgG associated with total serum IgG obtained the highest sensitivities and complemented the IgG index and oligoclonal bands.

CONCLUSION

These findings indicate that aforementioned indices may supplement existing indices and aid in the diagnosis of MS.

Sarcoidosis and its relation to other immune-mediated diseases: Epidemiological insights

Several epidemiological studies show a co-occurrence of sarcoidosis with other immune-mediated diseases (IMD). There are many similarities between sarcoidosis and IMDs in their geographical distribution and risk factors. Understanding these similarities and identifying the differences can help us to better understand sarcoidosis and put it into context with other IMDs. In this review, we present the current knowledge about the overlap between sarcoidosis and other IMDs derived from epidemiological studies. Epidemiologic methods utilize study design and statistical analysis to describe the patterns in data and, ideally, identify causal relationships between an exposure and a health outcome. We discuss how study design and analysis may affect the interpretation of epidemiological studies on this topic and highlight some theories that attempt to explain the relation between sarcoidosis and other IMDs.

TianTan vaccinia virus-based EBV vaccines targeting both latent and lytic antigens elicits potent immunity against lethal EBV challenge in humanized mice

Epstein-Barr virus (EBV) infection has been related to multiple epithelial cancers and lymphomas. Current efforts in developing a prophylactic EBV vaccine have focused on inducing neutralizing antibodies. However, given the lifelong and persistent nature of EBV infection following primary infection, it is rationalized that an ideal vaccine should elicit both humoral and cellular immune responses targeting multiple stages of the EBV lifecycle. This study used a DNA vector and a TianTan vaccinia virus to express key EBV antigens, including BZLF1, EBNA1, EBNA3B, and gH/gL, to generate multi-antigen vaccines. The multi-antigen vaccine expressing all four antigens and the multi-antigen vaccine expressing BZLF1, EBNA1, and EBNA3B showed comparable protection effects and prevented 100% and 80% of humanized mice, respectively, from EBV-induced fatal B cell lymphoma by activating BZLF1, EBNA1, and EBNA3B specific T cell. The vaccine expressing lytic protein BZLF1 elicited stronger T cell responses and conferred superior protection compared to vaccines targeting single latent EBNA1 or EBNA3B. The vaccine solely expressing gH/gL exhibited no T cell protective effects in our humanized mice model. Our study implicates the potential of EBV vaccines that induce potent cellular responses targeting both latent and lytic phases of the EBV life cycle in the prevention of EBV-induced B cell lymphoma.

Clinical correlates of lifetime and current comorbidity patterns in autoimmune and inflammatory diseases

BACKGROUND

Autoimmune and inflammatory diseases (AIDs) are a heterogeneous group of disorders with diverse etiopathogenic mechanisms. This study explores the potential utility of family history, together with present and past comorbidities, in identifying distinct etiopathogenic subgroups. This approach may facilitate more accurate diagnosis, prognosis and personalized therapy.

METHODS

We performed a multiple correspondence analysis on patients' comorbidities, followed by hierarchical principal component clustering of clinical data from 48 healthy volunteers and 327 patients with at least one of 19 selected AIDs included in the TRANSIMMUNOM cross-sectional study.

RESULTS

We identified three distinct clusters characterized by: 1) the absence of comorbidities, 2) polyautoimmunity, and 3) polyinflammation. These clusters were further distinguished by specific comorbidities and biological parameters. Autoantibodies, allergies, and viral infections characterized the polyautoimmunity cluster, while older age, BMI, depression, cancer, hypertension, periodontal disease, and dyslipidemia characterized the polyinflammation cluster. Rheumatoid arthritis patients were distributed across all three clusters. They had higher DAS28 and prevalence of extra-articular manifestations when belonging to the polyinflammation and polyautoimmunity clusters, and also lower ACPA and RF seropositivity and higher pain scores within the polyinflammation cluster. We developed a model allowing to classify AID patients into comorbidity clusters.

CONCLUSIONS

In this study, we have uncovered three distinct comorbidity profiles among AID patients. These profiles suggest the presence of distinct etiopathogenic mechanisms underlying these subgroups. Validation, longitudinal stability assessment, and exploration of their impact on therapy efficacy are needed for a comprehensive understanding of their potential role in personalized medicine.

High heterogeneity of cross-reactive immunoglobulins in multiple sclerosis presumes combining of B-cell epitopes for diagnostics: a case-control study

Background

Multiple sclerosis (MS) is a neuroinflammatory disease triggered by a combination of genetic traits and external factors. Autoimmune nature of MS is proven by the identification of pathogenic T cells, but the role of autoantibody-producing B cells is less clear. A comprehensive understanding of the development of neuroinflammation and the identification of targeted autoantigens are crucial for timely diagnosis and appropriate treatment.

Methods

An expression library of 44-mer overlapping peptides from a panel of putative autoantigenic human proteins was employed for modified Phage ImmunoPrecipitation Sequencing (PhIP-Seq) to identify B cell peptide epitopes from MS patients. Individual peptides extracted by PhIP-Seq were tested by ELISA to characterize their affinity towards IgG from both MS patients and healthy donors (HD). Three candidate auto-peptides were used for isolating autoreactive antigen-specific IgGs from the serum of MS patients.

Results

Autoantibody screening revealed high heterogeneity of IgG response in MS. The autoantigenic genesis of the PhIP-Seq-identified peptides was further strengthened by clinical ELISA testing of 11 HD and 16 MS donors. Validation experiments on independent cohorts of 22 HD and 28 MS patients confirmed statistically significant elevated titers of IgG specific to spectrin alpha chain (SPTAN1) in the serum of MS patients compared to HD. The levels of anti-SPTAN1 IgG correlated in serum and cerebrospinal fluid (CSF). Isolated autoreactive antigen-specific IgG exhibited increased cross-reactivity to a panel of PhIP-Seq-identified antigenic peptides. Serum IgG from MS patients were reactive to latent membrane protein (LMP1) of Epstein-Barr virus, a potential trigger of MS. Discovered antigenic peptides from SPTAN1, protein-tyrosine kinase 6 (PTK6), periaxin (PRX), and LMP1 were tested as potential biomarker panel for MS diagnostics. We concluded that the combination of particular peptides from SPTAN1, PTK6, PRX and LMP1 could be implemented as a four-peptide biomarker panel for MS diagnosis (area under the curve (AUC) of 0.818 for discriminating between HD and MS).

Conclusions

This study supports the concept that the specificity of autoreactive IgG in MS is highly heterogeneous. Despite that we suggest that the combination of several B-cell epitopes could be employed as reliable and simple test for MS diagnostics.

SARS-CoV-2 and HSV-1 Induce Amyloid Aggregation in Human CSF Resulting in Drastic Soluble Protein Depletion

The corona virus (SARS-CoV-2) pandemic and the resulting long-term neurological complications in patients, known as long COVID, have renewed interest in the correlation between viral infections and neurodegenerative brain disorders. While many viruses can reach the central nervous system (CNS) causing acute or chronic infections (such as herpes simplex virus 1, HSV-1), the lack of a clear mechanistic link between viruses and protein aggregation into amyloids, a characteristic of several neurodegenerative diseases, has rendered such a connection elusive. Recently, we showed that viruses can induce aggregation of purified amyloidogenic proteins via the direct physicochemical mechanism of heterogeneous nucleation (HEN). In the current study, we show that the incubation of HSV-1 and SARS-CoV-2 with human cerebrospinal fluid (CSF) leads to the amyloid aggregation of several proteins known to be involved in neurodegenerative diseases, such as APLP1 (amyloid β precursor like protein 1), ApoE, clusterin, α2-macroglobulin, PGK-1 (phosphoglycerate kinase 1), ceruloplasmin, nucleolin, 14-3-3, transthyretin, and vitronectin. Importantly, UV-inactivation of SARS-CoV-2 does not affect its ability to induce amyloid aggregation, as amyloid formation is dependent on viral surface catalysis via HEN and not its ability to replicate. Additionally, viral amyloid induction led to a dramatic drop in the soluble protein concentration in the CSF. Our results show that viruses can physically induce amyloid aggregation of proteins in human CSF and result in soluble protein depletion, thus providing a potential mechanism that may account for the association between persistent and latent/reactivating brain infections and neurodegenerative diseases.

Surface different charge ligands for modulating selenium nanoparticles formation and activating the interaction with proteins for effective anti-Herpes simplex virus l infection

Selenium-based nanoparticles exhibit antiviral activity by directly modulating immune function. Despite recent promising developments in utilizing selenium nanoparticles (Se NPs) against viral infections, the impact of surface ligand charge on the conformation and interaction with viral proteins, as well as the effectiveness of Se NPs in anti-Herpes simplex virus 1 (HSV-1) infection remains unexplored. In this study, three types of selenium nanoparticles (CTAB-Se, PVP-Se, SDS-Se) with distinct surface charges were synthesized by modifying the surface ligands. We found that apart from differences in surface charge, the size, morphology, and crystal structure of the three types of Se NPs were similar. Notably, although the lipophilicity and cellular uptake of SDS-Se with a negative charge were lower compared to positively charged CTAB-Se and neutrally charged PVP-Se, SDS-Se exhibited the strongest protein binding force during interaction with HSV-1. Consequently, SDS-Se demonstrated the most potent anti-HSV-1 activity and safeguarded normal cells from damage. The mechanistic investigation further revealed that SDS-Se NPs effectively inhibited the proliferation and assembly of HSV-1 by powerfully suppressing the key genes and proteins of HSV-1 at various stages of viral development. Hence, this study highlights the significant role of surface ligand engineering in the antiviral activity of Se NPs, presenting a viable approach for synthesizing Se NPs with tailored antiviral properties by modulating surface charge. This method holds promise for advancing research on the antiviral capabilities of Se NPs.

Structures of Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus virions reveal species-specific tegument and envelope features

Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are classified into the gammaherpesvirus subfamily of Herpesviridae, which stands out from its alpha- and betaherpesvirus relatives due to the tumorigenicity of its members. Although structures of human alpha- and betaherpesviruses by cryogenic electron tomography (cryoET) have been reported, reconstructions of intact human gammaherpesvirus virions remain elusive. Here, we structurally characterize extracellular virions of EBV and KSHV by deep learning-enhanced cryoET, resolving both previously known monomorphic capsid structures and previously unknown pleomorphic features beyond the capsid. Through subtomogram averaging and subsequent tomogram-guided sub-particle reconstruction, we determined the orientation of KSHV nucleocapsids from mature virions with respect to the portal to provide spatial context for the tegument within the virion. Both EBV and KSHV have an eccentric capsid position and polarized distribution of tegument. Tegument species span from the capsid to the envelope and may serve as scaffolds for tegumentation and envelopment. The envelopes of EBV and KSHV are less densely populated with glycoproteins than those of herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV), representative members of alpha- and betaherpesviruses, respectively. Also, we observed fusion protein gB trimers exist within triplet arrangements in addition to standalone complexes, which is relevant to understanding dynamic processes such as fusion pore formation. Taken together, this study reveals nuanced yet important differences in the tegument and envelope architectures among human herpesviruses and provides insights into their varied cell tropism and infection.

IMPORTANCE

Discovered in 1964, Epstein-Barr virus (EBV) is the first identified human oncogenic virus and the founding member of the gammaherpesvirus subfamily. In 1994, another cancer-causing virus was discovered in lesions of AIDS patients and later named Kaposi's sarcoma-associated herpesvirus (KSHV), the second human gammaherpesvirus. Despite the historical importance of EBV and KSHV, technical difficulties with isolating large quantities of these viruses and the pleiomorphic nature of their envelope and tegument layers have limited structural characterization of their virions. In this study, we employed the latest technologies in cryogenic electron microscopy (cryoEM) and tomography (cryoET) supplemented with an artificial intelligence-powered data processing software package to reconstruct 3D structures of the EBV and KSHV virions. We uncovered unique properties of the envelope glycoproteins and tegument layers of both EBV and KSHV. Comparison of these features with their non-tumorigenic counterparts provides insights into their relevance during infection.

Engineered Immune Constructs Alter Antigen-Specific Immune Tolerance and Confer Durable Protection in Myelin-Driven Autoimmunity

Autoimmune diseases are broadly characterized as a failure in immune tolerance. In multiple sclerosis (MS), autoreactive immune cells attack the protective myelin sheath lining neurons in the central nervous system. Therapeutic strategies that selectively and durably restore immune tolerance without broad immunosuppression are urgently needed for MS. Our lab has developed assemblies of immune constructs built entirely from myelin antigen (MOG35-55 or PLP139-151) and regulatory innate immune cues (GpG) using layer-by-layer self-assembly. Here, we present mechanistic and translational data showing these assemblies confer therapeutic benefits in a range of clinically relevant disease contexts, including progressive disease in male mice and in relapsing-remitting disease that mimics the intermittent bouts of disease and remission most MS patients initially experience. Here, the antigen component in the complexes is matched to the disease-causing antigen, resulting in a decrease in paralysis in these models. We show that subcutaneous delivery of assemblies durably prevents diseases and drives tolerance by regulatory remodeling of the draining lymph node. Importantly, we show that subcutaneously delivered assemblies recruit and expand antigen-specific regulatory T cells (TREGS) in draining lymph nodes. Finally, we find a shift of these recruited TREGS from a resting to an activated phenotype. Taken together, these data inform the design of therapeutics for antigen-specific tolerance that could combat autoimmunity by exploiting the role of innate pathways in a disease.

Comprehensive phage display viral antibody profiling using VirScan: potential applications in chronic immune-mediated disease

Phage immunoprecipitation sequencing (PhIP-Seq) is a high-throughput platform that uses programmable phage display for serology. VirScan, a specific PhIP-Seq library encoding viral peptides from all known human viruses, enables comprehensive quantification of past viral exposures. We review its use in immune-mediated diseases (IMDs), highlighting its utility in identifying viral exposures in the context of IMD development. Finally, we evaluate its potential for precision medicine by integrating it with other large-scale omics data sets.

Chronic Viral Reactivation and Associated Host Immune Response and Clinical Outcomes in Acute COVID-19 and Post-Acute Sequelae of COVID-19

Chronic viral infections are ubiquitous in humans, with individuals harboring multiple latent viruses that can reactivate during acute illnesses. Recent studies have suggested that SARS-CoV-2 infection can lead to reactivation of latent viruses such as Epstein-Barr Virus (EBV) and cytomegalovirus (CMV), yet, the extent and impact of viral reactivation in COVID-19 and its effect on the host immune system remain incompletely understood. Here we present a comprehensive multi-omic analysis of viral reactivation of all known chronically infecting viruses in 1,154 hospitalized COVID-19 patients, from the Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC) study, who were followed prospectively for twelve months. We reveal significant reactivation of Herpesviridae, Enteroviridae, and Anelloviridae families during acute stage of COVID-19 (0-40 days post-hospitalization), each exhibiting distinct temporal dynamics. We also show that viral reactivation correlated with COVID-19 severity, demographic characteristics, and clinical outcomes, including mortality. Integration of cytokine profiling, cellular immunophenotyping, metabolomics, transcriptomics, and proteomics demonstrated virus-specific host responses, including elevated pro-inflammatory cytokines (e.g. IL-6, CXCL10, and TNF), increased activated CD4+ and CD8+ T-cells, and upregulation of cellular replication genes, independent of COVID-19 severity and SARS-CoV-2 viral load. Notably, persistent Anelloviridae reactivation during convalescence (≥3 months post-hospitalization) was associated with Post-Acute Sequelae of COVID-19 (PASC) symptoms, particularly physical function and fatigue. Our findings highlight a remarkable prevalence and potential impact of chronic viral reactivation on host responses and clinical outcomes during acute COVID-19 and long term PASC sequelae. Our data provide novel immune, transcriptomic, and metabolomic biomarkers of viral reactivation that may inform novel approaches to prognosticate, prevent, or treat acute COVID-19 and PASC.

Prokaryote- and Eukaryote-Based Expression Systems: Advances in Post-Pandemic Viral Antigen Production for Vaccines

This review addresses the ongoing global challenge posed by emerging and evolving viral diseases, underscoring the need for innovative vaccine development strategies. It focuses on the modern approaches to creating vaccines based on recombinant proteins produced in different expression systems, including bacteria, yeast, plants, insects, and mammals. This review analyses the advantages, limitations, and applications of these expression systems for producing vaccine antigens, as well as strategies for designing safer, more effective, and potentially 'universal' antigens. The review discusses the development of vaccines for a range of viral diseases, excluding SARS-CoV-2, which has already been extensively studied. The authors present these findings with the aim of contributing to ongoing research and advancing the development of antiviral vaccines.

Patient iPSC models reveal glia-intrinsic phenotypes in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease of the central nervous system (CNS), resulting in neurological disability that worsens over time. While progress has been made in defining the immune system's role in MS pathophysiology, the contribution of intrinsic CNS cell dysfunction remains unclear. Here, we generated a collection of induced pluripotent stem cell (iPSC) lines from people with MS spanning diverse clinical subtypes and differentiated them into glia-enriched cultures. Using single-cell transcriptomic profiling and orthogonal analyses, we observed several distinguishing characteristics of MS cultures pointing to glia-intrinsic disease mechanisms. We found that primary progressive MS-derived cultures contained fewer oligodendrocytes. Moreover, MS-derived oligodendrocyte lineage cells and astrocytes showed increased expression of immune and inflammatory genes, matching those of glia from MS postmortem brains. Thus, iPSC-derived MS models provide a unique platform for dissecting glial contributions to disease phenotypes independent of the peripheral immune system and identify potential glia-specific targets for therapeutic intervention.

How Epstein Barr Virus Causes Lymphomas

Since Epstein-Barr Virus (EBV) was isolated 60 years ago, it has been studied clinically, epidemiologically, immunologically, and molecularly in the ensuing years. These combined studies allow a broad mechanistic understanding of how this ubiquitous human pathogen which infects more than 90% of adults can rarely cause multiple types of lymphomas. We survey these findings to provide a coherent description of its oncogenesis.

Preclinical characterization of MTX-101: a novel bispecific CD8 Treg modulator that restores CD8 Treg functions to suppress pathogenic T cells in autoimmune diseases

Introduction

Regulatory CD8 T cells (CD8 Treg) are responsible for the selective killing of self-reactive and pathogenic CD4 T cells. In autoimmune disease, CD8 Treg may accumulate in the peripheral blood but fail to control the expansion of pathogenic CD4 T cells that subsequently cause tissue destruction. This CD8 Treg dysfunction is due in part to the expression of inhibitory killer immunoglobulin-like receptors (KIR; KIR2DL isoforms [KIR2DL1, KIR2DL2, and KIR2DL3]); these molecules serve as autoimmune checkpoints and limit CD8 Treg activation.

Methods

Here we describe the pre-clinical characterization of MTX-101, a bispecific antibody targeting inhibitory KIR and CD8. Using human peripheral blood mononuculear cells (PBMC) derived from healthy donors and autoimmune patients, humanized mouse models, and human derived tissue organoids, we evaluated the molecular mechanisms and functional effects of MTX-101.

Results

By binding to KIR, MTX-101 inhibited KIR signaling that can restore CD8 Treg ability to eliminate pathogenic CD4 T cells. MTX-101 bound and activated CD8 Treg in human peripheral blood mononuclear cells (PBMC), resulting in increased CD8 Treg cytolytic capacity, activation, and prevalence. Enhancing CD8 Treg function with MTX-101 reduced pathogenic CD4 T cell expansion and inflammation, without increasing pro-inflammatory cytokines or activating immune cells that express either target alone. MTX-101 reduced antigen induced epithelial cell death in disease affected tissues, including in tissue biopsies from individuals with autoimmune disease (i.e., celiac disease, Crohn's disease). The effects of MTX-101 were specific to autoreactive CD4 T cells and did not suppress responses to viral and bacterial antigens. In a human PBMC engrafted Graft versus Host Disease (GvHD) mouse model of acute inflammation, MTX-101 bound CD8 Treg and delayed onset of disease. MTX-101 induced dose dependent binding, increased prevalence and cytolytic capacity of CD8 Treg, as well as increased CD4 T cell death. MTX-101 selectively bound CD8 Treg without unwanted immune cell activation or increase of pro-inflammatory serum cytokines and exhibited an antibody-like half-life in pharmacokinetic and exploratory tolerability studies performed using IL-15 transgenic humanized mice with engrafted human lymphocytes, including CD8 Treg at physiologic ratios.

Conclusion

Collectively, these data support the development of MTX-101 for the treatment of autoimmune diseases.

Coeliac disease as a model for understanding multiple sclerosis

The genetic architecture of multiple sclerosis (MS) is similar to that of coeliac disease, with human leukocyte antigen (HLA) being the greatest genetic determinant in both diseases. Furthermore, similar to the involvement of gluten in coeliac disease, Epstein-Barr virus (EBV) infection is now widely considered to be an important environmental factor in MS. The molecular basis for the HLA association in coeliac disease is well defined, and B cells have a clear role in antigen presentation to gluten-specific CD4+ T cells. By contrast, the mechanisms underlying the HLA association of MS are unknown but accumulating evidence indicates a similar role of B cells acting as antigen-presenting cells. The growing parallels suggest that much could be learned about the mechanisms of MS by using coeliac disease as a model. In this Perspective article, we discuss the insights that could be gained from these parallels and consider the possibility of antiviral treatment against EBV as a therapy for MS that is analogous to the gluten-free diet in coeliac disease.

New insights in the pathogenic mechanism of multiple sclerosis: Is Epstein-Barr virus associated with optic nerve involvement?

INTRODUCTION

There are no reports in the literature studying the possible relationship between Epstein-Barr virus (EBV) and optic nerve involvement in multiple sclerosis (MS). The aim of our study was to analyze the association between EBV antibodies titres and optical coherence tomography (OCT) and OCT angiography (OCTA) quantitative parameters.

METHODS

We conducted a retrospective study. The study included 98 eyes of 49 patients with MS. Years of MS duration, relapse count, history of optic neuritis (ON), and immunoglobulin (Ig) G antibodies to the EBV viral capsid antigen (VCA) were recorded from each patient. Also, OCT analysis (including retinal nerve fibre layer (RNFL) thickness and ganglion cell-inner plexiform layer (GCIPL) thickness) and OCTA analysis (including perfusion density (PD) and flux index (FI) of the radial peripapillary capillary plexus) were performed in each participant.

RESULTS

No significant associations were observed between anti-EBV antibody levels and OCT or OCTA parameters (p > 0,05). Correlation analysis between OCT and OCTA measurements showed a significant positive correlation between RNFL thickness and GCIPL thickness with peripapillary PD and FI (p < 0,035). Subgroup analysis revealed a significant diminution of RNFL thickness, GCIPL thickness and peripapillary PD and FI (p < 0,05) in the ON group.

CONCLUSION

We were unable to demonstrate a significant association between anti-EBV VCA IgG antibody titres and OCT or OCTA parameters. Nonetheless, further longitudinal studies are needed to explore the possible association of EBV with optic nerve involvement in MS.

mRNA vaccines for infectious diseases - advances, challenges and opportunities

The concept of mRNA-based vaccines emerged more than three decades ago. Groundbreaking discoveries and technological advancements over the past 20 years have resolved the major roadblocks that initially delayed application of this new vaccine modality. The rapid development of nucleoside-modified COVID-19 mRNA vaccines demonstrated that this immunization platform is easy to develop, has an acceptable safety profile and can be produced at a large scale. The flexibility and ease of antigen design have enabled mRNA vaccines to enter development for a wide range of viruses as well as for various bacteria and parasites. However, gaps in our knowledge limit the development of next-generation mRNA vaccines with increased potency and safety. A deeper understanding of the mechanisms of action of mRNA vaccines, application of novel technologies enabling rational antigen design, and innovative vaccine delivery strategies and vaccination regimens will likely yield potent novel vaccines against a wide range of pathogens.

Epstein-Barr virus as a potentiator of autoimmune diseases

The Epstein-Barr virus (EBV) is epidemiologically associated with development of autoimmune diseases, including systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis and multiple sclerosis. Although there is well-established evidence for this association, the underlying mechanistic basis remains incompletely defined. In this Review, we discuss the role of EBV infection as a potentiator of autoimmune rheumatic diseases. We review the EBV life cycle, viral transcription programmes, serological profiles and lytic reactivation. We discuss the epidemiological and mechanistic associations of EBV with systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis and multiple sclerosis. We describe the potential mechanisms by which EBV might promote autoimmunity, including EBV nuclear antigen 1-mediated molecular mimicry of human autoantigens; EBV-mediated B cell reprogramming, including EBV nuclear antigen 2-mediated dysregulation of autoimmune susceptibility genes; EBV and host genetic factors, including the potential for autoimmunity-promoting strains of EBV; EBV immune evasion and insufficient host responses to control infection; lytic reactivation; and other mechanisms. Finally, we discuss the therapeutic implications and potential therapeutic approaches to targeting EBV for the treatment of autoimmune disease.

Molecular mimicry as a mechanism of viral immune evasion and autoimmunity

Mimicry of host protein structures, or 'molecular mimicry', is a common mechanism employed by viruses to evade the host's immune system. Short linear amino acid (AA) molecular mimics can elicit cross-reactive antibodies and T cells from the host, but the prevalence of such mimics throughout the human virome has not been fully explored. Here we evaluate 134 human-infecting viruses and find significant usage of linear mimicry across the virome, particularly those in the Herpesviridae and Poxviridae families. Furthermore, host proteins related to cellular replication and inflammation, autosomes, the X chromosome, and thymic cells are enriched as viral mimicry targets. Finally, we find that short linear mimicry from Epstein-Barr virus (EBV) is higher in auto-antibodies found in patients with multiple sclerosis than previously appreciated. Our results thus hint that human-infecting viruses leverage mimicry in the course of their infection, and that such mimicry may contribute to autoimmunity, thereby prompting potential targets for therapies.

Evidence that autoantibody production may be driven by acute Epstein-Barr virus infection in Sjögren's disease

OBJECTIVES

Sjögren's disease (SD) is an autoimmune disease affecting the exocrine glands that is associated with autoantibodies against Ro60/SS-A, anti-Ro52/TRIM21, La/SS-B and others. We examined the role of acute Epstein-Barr virus (EBV) infection in the pathogenesis of these autoantibodies in a previously healthy patient (patient 1) with primary EBV infection who developed SD with anti-Ro/La and anti-Smith/U1 ribonucleoprotein (Sm/U1RNP) autoantibodies and had lymphoplasmacytic foci on labial salivary gland biopsy.

METHODS

Immune responses to Epstein-Barr nuclear antigen-1 (EBNA1) and the Ro52/Ro60/La and Sm/U1RNP autoantigens and peptides were examined by immunoassay in patient 1, healthy and disease controls.

RESULTS

Anti-Ro52 and anti-Ro60 autoantibodies were present 7 days after primary infection and underwent IgM to IgG switching, suggesting that EBV infection promoted their production. More than 7 months after primary infection, new and increasing levels of antibodies against EBNA1 and the U1RNP autoantigen appeared concomitantly. These antibodies bound homologous peptide sequences shared by EBNA1, SmB' and the U1-C (U1RNP) protein, consistent with induction by molecular mimicry. Although Ro60 and EBNA1 crossreact immunologically, we found that anti-Ro60/anti-Ro52 antibody production was stimulated by acute EBV infection long before the onset of anti-EBNA1. Unexpectedly, a subset of healthy control sera had anti-SmB' peptide antibodies that were not correlated with anti-EBNA1 peptide antibodies. In contrast, anti-SmB' and EBNA1 peptide antibody levels correlated in anti-Sm/U1RNP+ lupus sera.

CONCLUSIONS

Primary EBV infection can promote anti-Ro60/anti-Ro52 and anti-U1RNP responses, though by different mechanisms. Some healthy individuals produce anti-SmB' peptide autoantibodies independently of a response to EBNA1.

CD4 T cells restricted to DRB1*15:01 recognize two Epstein-Barr virus glycoproteins capable of intracellular antigen presentation

Both genetic and environmental factors contribute to multiple sclerosis (MS) risk. Infection with the Epstein-Barr virus (EBV) is the strongest environmental risk factor, and HLA-DR15 is the strongest genetic risk factor for MS. We employed computational methods and in vitro assays for CD4 T cell activation to investigate the DR15-restricted response to EBV. Using a machine learning-based HLA ligand predictor, the EBV glycoprotein B (gB) was predicted to be enriched in epitopes restricted to presentation by DRB1*15:01. In DR15-positive individuals, two epitopes comprised the major CD4 T cell response to gB. Surprisingly, the expression of recombinant gB in a DR15-homozygous B cell line or primary autologous B cells elicited a CD4 T cell response, indicating that intracellular gB was loaded onto HLA class II molecules. By deleting the signal sequence of gB, we determined that this pathway for direct activation of CD4 T cells was dependent on trafficking to the endoplasmic reticulum (ER) within the B cell. We screened seven recombinant EBV antigens from the ER compartment for immune responses in DR15-negative vs. DR15-homozygous individuals. In addition to gB, gH was a key CD4 T cell target in individuals homozygous for DR15. Compared to non-DR15 controls, DR15-homozygotes had significantly higher T cell responses to both gB and gH but not to EBV latent or lytic antigens overall. Responses to gB and gH were slightly elevated in DR15 homozygotes with MS. Our results link MS environmental and genetic risk factors by demonstrating that HLA-DR15 dictates CD4 T cell immunity to EBV antigens.

Intrathecal IgG and IgM synthesis correlates with neurodegeneration markers and corresponds to meningeal B cell presence in MS

Intrathecal synthesis of immunoglobulins (Igs) is a key hallmark of multiple sclerosis (MS). B cells are known to accumulate in the leptomeninges of MS patients and associate with pathology in the underlying cortex and a more severe disease course. However, the role of locally produced antibodies in MS brain pathology is poorly understood. Here, we quantified the protein levels of IgA, IgM, IgG and albumin in serum and cerebrospinal fluid (CSF) samples of 80 MS patients and 28 neurological controls to calculate Ig indices. In addition, we quantified presence of meningeal IgA+, IgM+ and IgG+ B cells in post-mortem brain tissue of 20 MS patients and 6 controls using immunostainings. IgM and IgG, but not IgA, indices were increased in CSF of MS patients compared to controls, with no observed differences between MS disease types. Both IgM and IgG indices correlated significantly with neurofilament light (NfL) levels in CSF, but not with clinical or radiological parameters of disease. Similarly, IgG+ and IgM+ B cells were increased in MS meninges compared to controls, whereas IgA+ B cells were not. Neuronal loss did not differ between sections with low or high IgA+, IgM+ and IgG+ B cells, but was increased in sections with high numbers of all CD19+ meningeal B cells. Similarly, high presence of CD19+ meningeal B cells and IgG+ meningeal B cells associated with increased microglial density in the underlying cortex. Taken together, intrathecal synthesis of IgG and IgM is elevated in MS, which corresponds to an increased number of IgG+ and IgM+ B cells in MS meninges. The significant correlation between intrathecal IgG and IgM production and NfL levels, and increased microglial activation in cortical areas adjacent to meningeal infiltrates with high levels of IgG+ B cells indicate a role for intrathecal IgM- and IgG-producing B cells in neuroinflammatory and degenerative processes in MS.

Epstein-Barr virus induces host shutoff extensively via BGLF5-independent mechanisms

Epstein-Barr virus (EBV) is a ubiquitous oncogenic virus associated with multiple cancers and autoimmune diseases. Unlike most herpesviruses, EBV reactivation from latency occurs asymptomatically, allowing it to spread efficiently to other hosts. However, available models are limited by the inefficient and asynchronous reactivation from latency into lytic replication. To address this problem, we develop a dual-fluorescent lytic reporter (DFLR) EBV that specifically labels cells in the early and late stages of replication. Using lymphoblastoid cell lines transformed by DFLR EBV as a model for EBV reactivation in B cells, we observe extensive reprogramming of the host cell transcriptome during lytic cycle progression. This includes widespread shutoff of host gene expression and disruption of mRNA processing. Unexpectedly, host shutoff remains extensive even in cells infected with DFLR EBV deleted for the BGLF5 nuclease. These findings implicate BGLF5-independent mechanisms as the primary drivers of host transcriptome remodeling during EBV lytic replication.

Epstein-Barr virus replication within differentiated epithelia requires pRb sequestration of activator E2F transcription factors

Epstein-Barr virus (EBV) co-infections with human papillomavirus (HPV) have been observed in oropharyngeal squamous cell carcinoma. Modeling EBV/HPV co-infection in organotypic epithelial raft cultures revealed that HPV16 E7 inhibited EBV productive replication through the facilitated degradation of the retinoblastoma protein pRb/p105. To further understand how pRb is required for EBV productive replication, we generated CRISPR-Cas9 pRb knockout (KO) normal oral keratinocytes (NOKs) in the context of wild-type and mutant K120E p53. EBV replication was examined in organotypic rafts as a physiological correlate for epithelial differentiation. In pRb KO rafts, EBV DNA copy number was statistically decreased compared to vector controls, regardless of p53 context. Loss of pRb did not affect EBV binding or internalization of calcium-treated NOKs or early infection of rafts. Rather, the block in EBV replication correlated with impaired immediate early gene expression. An EBV infection time course in rafts with mutant p53 demonstrated that pRb-positive basal cells were initially infected with delayed replication occurring in differentiated layers. Loss of pRb showed increased S-phase progression makers and elevated activator E2F activity in raft tissues. Complementation with a panel of pRb/E2F binding mutants showed that wild type or pRb∆685 mutant capable of E2F binding reduced S-phase marker gene expression, rescued EBV DNA replication, and restored BZLF1 expression in pRb KO rafts. However, pRb KO complemented with pRb661W mutant, unable to bind E2Fs, failed to rescue EBV replication in raft culture. These findings suggest that EBV productive replication in differentiated epithelium requires pRb inhibition of activator E2Fs to restrict S-phase progression.IMPORTANCEA subset of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma is co-positive for Epstein-Barr virus (EBV). Potential oncogenic viral interactions revealed that HPV16 E7 inhibited productive EBV replication within the differentiated epithelium. As E7 mediates the degradation of pRb, we aimed to establish how pRb is involved in EBV replication. In the context of differentiated epithelium using organotypic raft culture, we evaluated how the loss of pRb affects EBV lytic replication to better comprehend EBV contributions to carcinogenesis. In this study, ablation of pRb interfered with EBV replication at the level of immediate early gene expression. Loss of pRb increased activator E2Fs and associated S-phase gene expression throughout the differentiated epithelium. Complementation studies showed that wild type and pRb mutant capable of binding to E2F rescued EBV replication, while pRb mutant lacking E2F binding did not. Altogether, these studies support that in differentiated tissues, HPV16 E7-mediated degradation of pRb inhibits EBV replication through unregulated E2F activity.

Transactivation of Human Endogenous Retroviruses by Viruses

Human endogenous retroviruses (HERVs) are remnants of ancient retroviral infections that are part the human genome and are normally silenced through epigenetic mechanisms. However, HERVs can be induced by various host and environmental factors, including viral infection, and transcriptionally active HERVs have been implicated in various physiological processes. In this review, we summarize mounting evidence of transactivation of HERVs by a wide range of DNA and RNA viruses. Though a mechanistic understanding of this phenomenon and the biological implications are still largely missing, the link between exogenous and endogenous viruses is intriguing. Considering the increasing recognition of the role of viral infections in disease, understanding these interactions provides novel insights into human health.

Antigen specificity of clonally-enriched CD8+ T cells in multiple sclerosis

CD8+ T cells are the dominant lymphocyte population in multiple sclerosis (MS) lesions where they are highly clonally expanded. The clonal identity, function, and antigen specificity of CD8+ T cells in MS are not well understood. Here we report a comprehensive single-cell RNA-seq and T cell receptor (TCR)-seq analysis of the cerebrospinal fluid (CSF) and blood from a cohort of treatment-naïve MS patients and control participants. A small subset of highly expanded and activated CD8+ T cells were enriched in the CSF in MS that displayed high activation, cytotoxicity and tissue-homing transcriptional profiles. Using a combination of unbiased and targeted antigen discovery approaches, MS-derived CD8+ T cell clonotypes recognizing Epstein-Barr virus (EBV) antigens and multiple novel mimotopes were identified. These findings shed vital insight into the role of CD8+ T cells in MS and pave the way towards disease biomarkers and therapeutic targets.

Neoself-antigens are the primary target for autoreactive T cells in human lupus

Major histocompatibility complex class II (MHC-II) is the most significant genetic risk factor for systemic lupus erythematosus (SLE), but the nature of the self-antigens that trigger autoimmunity remains unclear. Unusual self-antigens, termed neoself-antigens, are presented on MHC-II in the absence of the invariant chain essential for peptide presentation. Here, we demonstrate that neoself-antigens are the primary target for autoreactive T cells clonally expanded in SLE. When neoself-antigen presentation was induced by deleting the invariant chain in adult mice, neoself-reactive T cells were clonally expanded, leading to the development of lupus-like disease. Furthermore, we found that neoself-reactive CD4+ T cells were significantly expanded in SLE patients. A high frequency of Epstein-Barr virus reactivation is a risk factor for SLE. Neoself-reactive lupus T cells were activated by Epstein-Barr-virus-reactivated cells through downregulation of the invariant chain. Together, our findings imply that neoself-antigen presentation by MHC-II plays a crucial role in the pathogenesis of SLE.

Pathogenesis of multiple sclerosis: genetic, environmental and random mechanisms

BACKGROUND

The pathogenesis of multiple sclerosis (MS) requires both genetic factors and environmental events. The question remains, however, whether these factors and events completely describe the MS disease process. This question was addressed using the Canadian MS data, which includes 29 478 individuals, estimated to represent 65-83% of all Canadian patients with MS.

METHOD

The 'genetically-susceptible' subset of the population, (G), includes everyone who has any non-zero life-time chance of developing MS, under some environmental conditions. A 'sufficient' environmental exposure, for any genetically-susceptible individual, includes every set of environmental conditions, each of which is 'sufficient', by itself, to cause MS in that person. This analysis incorporates many epidemiological parameters, involved in MS pathogenesis, only some of which are directly observable, and establishes 'plausible' value ranges for each parameter. Those parameter value combinations (ie, solutions) that fall within these plausible ranges are then determined.

RESULTS

Only a small proportion of the population (≤52%) has any possibility of developing MS, regardless of any environmental conditions that they could experience. Moreover, some of these genetically-susceptible individuals, despite their experiencing a 'sufficient' environmental exposure, will still not develop disease.

CONCLUSIONS

This analysis explicitly includes all of those genetic factors and environmental events (including their interactions), which are necessary for MS pathogenesis, regardless of whether these factors, events and interactions are known, suspected or as yet unrecognised. Nevertheless, in addition, a 'truly' random mechanism also seems to play a critical role in disease pathogenesis. This observation provides empirical evidence, which undermines the widely-held deterministic view of nature. Moreover, both sexes seem to share a similar genetic and environmental disease basis. If so, then it is this random mechanism, which is primarily responsible for the currently-observed differences in MS disease expression between susceptible women and susceptible men.

Glatiramer Acetate for the Treatment of Multiple Sclerosis: From First-Generation Therapy to Elucidation of Immunomodulation and Repair

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), with a putative autoimmune origin and complex pathogenesis. Modification of the natural history of MS by reducing relapses and slowing disability accumulation was first attained in the 1990 s with the development of the first-generation disease-modifying therapies. Glatiramer acetate (GA), a copolymer of L-alanine, L-lysine, L-glutamic acid, and L-tyrosine, was discovered due to its ability to suppress the animal model of MS, experimental autoimmune encephalomyelitis. Extensive clinical trials and long-term assessments established the efficacy and the safety of GA. Furthermore, studies of the therapeutic processes induced by GA in animal models and in MS patients indicate that GA affects various levels of the innate and the adaptive immune response, generating deviation from proinflammatory to anti-inflammatory pathways. This includes competition for binding to antigen presenting cells; driving dendritic cells, monocytes, and B-cells toward anti-inflammatory responses; and stimulating T-helper 2 and T-regulatory cells. The immune cells stimulated by GA reach the CNS and secrete in situ anti-inflammatory cytokines alleviating the pathological processes. Furthermore, cumulative findings reveal that in addition to its immunomodulatory effect, GA promotes neuroprotective repair processes such as neurotrophic factors secretion, remyelination, and neurogenesis. This review aims to provide an overview of MS pathology diagnosis and treatment as well as the diverse mechanism of action of GA. SIGNIFICANCE STATEMENT: Understanding the complex MS immune pathogenesis provided multiple targets for therapeutic intervention, resulting in a plethora of agents, with various mechanisms of action, efficacy, and safety profiles. However, promoting repair beyond the body's limited spontaneous extent is still a major challenge. GA, one of the first approved disease-modifying therapies, induces diverse immunomodulatory effects. Furthermore, GA treatment results in elevated neurotrophic factors secretion, remyelination and neurogenesis, supporting the notion that immunomodulatory treatment can support in situ a growth-promoting and repair environment.

Tertiary lymphoid structures and B-cell infiltration are IPF features with functional consequences

Background

Recent literature has shown the presence of B cells and autoantibodies in idiopathic pulmonary fibrosis (IPF) which would imply the presence of tertiary lymphoid structures (TLS, sites where the immune response is triggered), yet TLS are not considered features of the histological characteristics of IPF.

Aim

This study aims to quantify the presence, size, and degree of activation of TLS in biopsied and explanted lungs from patients with early- and late-IPF, never treated with antifibrotics, and relate their presence and activity to the clinical course, disease progression, and lung inflammation.

Methods

Immunohistochestry for B cells and CD4, CD8, and CD45 cells was performed in lung tissue from IPF patients: 18 at diagnosis (early), 39 explanted (end-stage), and 12 smoking controls. TLS activation was assessed by CD40 expression. Spirometry along 31 (12-72) months of follow-up was used to characterize end-stage IPF as slow progressors or rapid progressors.

Results

B cells, along with other inflammatory cells, were higher in early- and end-stage IPF than in controls (p < 0.001). In rapid progressors, all inflammatory cells were higher than in slow progressors (p < 0.05). TLS were present in 100% of early- and end-stage IPF and in 50% of controls. In end-stage IPF, the TLS area and activation score were higher than in early IPF (p < 0.0001; p = 0.005) and controls (p < 0.04; p < 0.002). TLS activation score correlated with FVC decline during follow-up in rapid progressors (r = 0.73; p = 0.007) but not in slow progressors.

Conclusions

A prominent B-cell infiltration, along with the presence of TLS, the activity of which correlates with FVC decline, is an important component of IPF from the beginning of the disease, likely playing an important role on its mechanism and progression.

Neurodegeneration and demyelination in multiple sclerosis

Progressive multiple sclerosis (PMS) is an immune-initiated neurodegenerative condition that lacks effective therapies. Although peripheral immune infiltration is a hallmark of relapsing-remitting MS (RRMS), PMS is associated with chronic, tissue-restricted inflammation and disease-associated reactive glial states. The effector functions of disease-associated microglia, astrocytes, and oligodendrocyte lineage cells are beginning to be defined, and recent studies have made significant progress in uncovering their pathologic implications. In this review, we discuss the immune-glia interactions that underlie demyelination, failed remyelination, and neurodegeneration with a focus on PMS. We highlight the common and divergent immune mechanisms by which glial cells acquire disease-associated phenotypes. Finally, we discuss recent advances that have revealed promising novel therapeutic targets for the treatment of PMS and other neurodegenerative diseases.

Epstein-Barr virus flare: A multiple sclerosis attack

Background

Multiple sclerosis (MS)-Epstein-Barr virus (EBV) relation is similar to doing a complicated puzzle: it consists of many pieces that become more and more clear as the issue is viewed from different sides. Based on the research findings, there is powerful evidence that EBV and MS have a strong relation where high levels of EBV DNA are able to be shown in all the spinal cord and the blood of the MS patients, but these are shown during disease relapses, and this implies a role in these illnesses. It kind of narrows the choices that you have to look for, just like how gathering evidence can lead to finding the missing person. In the analysis, new ways of EBV participation in MS progression are expected to be installed, and even new therapeutics are expected to be made.

Methods

A comprehensive literature search of PubMed was conducted until November 2023 to identify studies investigating the association between Epstein-Barr virus (EBV) infection and multiple sclerosis (MS). Only articles that met stringent criteria, including validation of EBV infection through laboratory testing, were included in the analysis.

Results

A total of 16 articles were identified as applicable for the background review, and this conformed with the discovery that the initiation of EBV/IM was consistent across various studies, namely, retrospective, cross-sectional, or prospective. The statistics reveal a glimpse into the need for prolonged research in studying the pattern of this link between EBV and MS. Novel treatment approaches targeting EBV, including adoptive T-cell therapy and gene-based immunotherapy, show promise in mitigating MS progression by targeting EBV-infected cells.

Conclusion

Clinical trials investigating antiviral therapies and vaccination strategies are underway, aiming to translate these findings into effective treatments for MS. Despite promising advances, challenges remain in developing EBV-targeted therapies for MS, including safety concerns and the multifactorial nature of MS pathogenesis. Advance treatment options that focus on EBV, such as adoptive T-cell therapy and gene-based immunotherapy, are shown to be effective in the improvement of MS management that targets the viral-infected cell. The clinical trials for antiviral drugs and vaccination tactics are going on to benefit from these findings and eventually to invent effective therapeutics for MS. While these new therapeutic directions may offer great promise, challenges remain in these approaches as safety concerns and complex factors that underlie MS pathology need to be taken care of. The ethical aspects linked to picking the patients and giving informed consent make the progress of EBV-related treatments are even more difficult. Future research is recommended so that the primary mechanisms through which EBV contributes to MS development will be elucidated; in addition, the main MS subtype sources must be addressed. Longitudinal studies and other advanced research technologies will provide hope because they can solve the complicated problems of MS due to viruses and look for new therapeutic targets. The review brings up EBV/IM disease as a vital aspect of MS susceptibility, encouraging research in the field of longitudinal studies. Although we have made advances, we are still far from clear on the labyrinthine pairing between EBV and MS and the development of therapeutic strategies to attack EBV infection in MS patients.