Complex interaction between mutant HNRNPA1 and gE of varicella zoster virus in pathogenesis of multiple sclerosis

The association between various viral infections and multiple sclerosis: An umbrella review on systematic review and meta-analysis

Multiple Sclerosis (MS) is one of the immune-mediated demyelinating disorders. Multiple components, including the environment and genetics, are possible factors in the pathogenesis of MS. Also, it can be said that infections are a key component of the host's response to MS development. Finally, we evaluated the relationship between different pathogens and MS disease in this umbrella research. We systematically collected and analysed multiple meta-analyses focused on one particular topic. We utilised the Scopus, PubMed, and Web of Science databases starting with inception until 30 May 2023. The methodological quality of the analysed meta-analysis has been determined based on Assessing the Methodological Quality of Systematic Reviews 2 and Grade, and graph construction and statistical analysis were conducted using Comprehensive Meta-Analysis. The Confidence Interval of effect size was 95% in meta-analyses, and p < 0.05 indicated a statistically meaningful relationship. The included studies evaluated the association between MS and 12 viruses containing SARS-CoV-2, Epstein-Barr virus (EBV), Hepatitis B virus, varicella-zoster virus (VZV), human herpesvirus 6 (HHV-6), HHV-7, HHV-8, HSV-1, HSV-2, Cytomegalovirus, Human Papillomavirus, and influenza. SARS-CoV-2, with a 3.74 odds ratio, has a significantly more potent negative effect on MS among viral infections. After that, EBV, HHV-6, HSV-2, and VZV, respectively, with 3.33, 2.81, 1.76, and 1.72 odds ratios, had a significantly negative relationship with MS (p < 0.05). Although the theoretical evidence mostly indicates that EBV has the greatest effect on MS, recent epidemiological studies have challenged this conclusion and put forward possibilities that SARS-CoV-2 is the culprit. Hence, it was necessary to investigate the effects of SARS-CoV-2 and EBV on MS.

Undervalued and novel roles of heterogeneous nuclear ribonucleoproteins in autoimmune diseases: Resurgence as potential biomarkers and targets

Autoimmune diseases are mainly characterized by the abnormal autoreactivity due to the loss of tolerance to specific autoantigens, though multiple pathways associated with the homeostasis of immune responses are involved in initiating or aggravating the conditions. The heterogeneous nuclear ribonucleoproteins (hnRNPs) are a major category of RNA-binding proteins ubiquitously expressed in a multitude of cells and have attracted great attentions especially with their distinctive roles in nucleic acid metabolisms and the pathogenesis in diseases like neurodegenerative disorders and cancers. Nevertheless, the interplay between hnRNPs and autoimmune disorders has not been fully elucidated. Virtually various family members of hnRNPs are increasingly identified as immune players and are pertinent to all kinds of immune-related processes including immune system development and innate or adaptive immune responses. Specifically, hnRNPs have been extensively recognized as autoantigens within and even beyond a myriad of autoimmune diseases, yet their diagnostic and prognostic values are seemingly underestimated. Molecular mimicry, epitope spreading and bystander activation may represent major putative mechanisms underlying the presence of autoantibodies to hnRNPs. Besides, hnRNPs play critical parts in regulating linchpin genes expressions that control genetic susceptibility, disease-linked functional pathways, or immune responses by interacting with other components particularly like microRNAs and long non-coding RNAs, thereby contributing to inflammation and autoimmunity as well as specific disease phenotypes. Therefore, comprehensive unraveling of the roles of hnRNPs is conducive to establishing potential biomarkers and developing better intervention strategies by targeting these hnRNPs in the corresponding disorders. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.

Immunopathogenesis of viral infections in neurological autoimmune disease

Autoimmune diseases develop due to self-tolerance failure in recognizing self and non-self-antigens. Several factors play a role in inducing autoimmunity, including genetic and environmental elements. Several studies demonstrated the causative role of viruses; however, some studies showed the preventive effect of viruses in the development of autoimmunity. Neurological autoimmune diseases are classified based on the targets of autoantibodies, which target intracellular or extracellular antigens rather than neurons. Several theories have been hypothesized to explain the role of viruses in the pathogenesis of neuroinflammation and autoimmune diseases. This study reviewed the current data on the immunopathogenesis of viruses in autoimmunity of the nervous system.

Case report: Varicella associated neuropsychiatric syndrome (VANS) in two pediatric cases

Background

Viral or bacterial infections can trigger auto-immune inflammatory reactions and conditions in children. Self-reactivity arises due to similarities in molecular structures between pathogenic microorganisms and regular body structures with consequent immune-cross reactions. Reactivation of latent Varicella Zoster Virus (VZV) infections can cause neurological sequalae, including cerebellitis, post-herpetic neuralgias, meningo/encephalitis, vasculopathy and myelopathy. We propose a syndrome caused by auto-immune reactivity triggered by molecular mimicry between VZV and the brain, culminating in a post-infectious psychiatric syndrome with childhood VZV infections.

Case presentation

Two individuals, a 6-year-old male and 10-year-old female developed a neuro-psychiatric syndrome 3-6 weeks following a confirmed VZV infection with intrathecal oligoclonal bands. The 6-year-old male presented with a myasthenic syndrome, behavior deterioration and regression in school, he was poorly responsive to IVIG and risperidone, however had a pronounced response to steroid treatment. The 10-year-old female presented with marked insomnia, agitation, and behavioral regression as well as mild bradykinesia. A trial of neuroleptics and sedatives resulted in a mild unsustained reduction in psychomotor agitation and IVIG was also unsuccessful, however the patient was very responsive to steroid therapy.

Conclusion

Psychiatric syndromes with evidence of intrathecal inflammation temporally related to VZV infections that are responsive to immune modulation have not been described before. Here we report two cases demonstrating neuro-psychiatric symptoms following VZV infection, with evidence of persistent CNS inflammation following the resolution of infection, and response to immune modulation.

T-Cell Response against Varicella Zoster Virus in Patients with Multiple Sclerosis during Relapse and Remission

An association between varicella zoster virus (VZV) and multiple sclerosis (MS) has been reported in Mexican populations. The aim of this study was to compare the response of T cells from MS patients, during relapse and remission, to in vitro stimulation with VZV, adenovirus (AV) and Epstein–Barr virus (EBV). Proliferation and cytokine secretion of T cells from 29 relapsing-remitting MS patients and 38 healthy controls (HC) were analyzed by flow cytometry after stimulating with VZV, AV or EBV. IgG and IgM levels against VZV and EBV were quantified using Enzyme-Linked Immunosorbent Assay. Relapsing MS patients showed a higher percentage of responding CD4+ and CD8+ T cells against VZV compared to AV. In HC and remitting MS patients, proliferation of CD4+ T cells was higher when stimulated with VZV as compared to EBV. Moreover, T cells isolated from remitting patients secreted predominantly Th1 cytokines when cell cultures were stimulated with VZV. Finally, high concentration of anti-VZV IgG was found in sera from patients and controls. The results support previous studies of an VZV-MS association in the particular population studied and provide additional information about the possible role of this virus in the pathogenesis of MS.

Geographic heterogeneity in the association of varicella-zoster virus seropositivity and multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Although there has long been a suspected association between varicella-zoster virus (VZV) and multiple sclerosis (MS), the connection has remained unclear. In this study, we performed a meta-analysis in an attempt to assess the association between VZV IgG serostatus and MS.

METHODS

A literature search was performed using three databases: MEDLINE, EMBASE, and Cochrane. Eligible results included observational studies investigating the seroprevalence of VZV immunoglobulin G (IgG) in adults with MS versus non-MS controls. Two authors performed a screen of the search results, evaluating them for quality and relevant outcomes. Using a random-effect model, we estimated pooled odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The literature search yielded 1,268 articles, 8 of which (2,266 MS patients and 1,818 controls) were eligible for inclusion in the meta-analysis. Evaluation of all included studies together showed no significant association between VZV IgG seropositivity and MS (OR 1.439; 95%CI, 0.503-4.118; p 0.497). However, when analyzed in subgroups based on geographical area, studies performed in Asian countries showed VZV IgG seropositivity was more common in MS patients than in controls (OR 4.470; 95%CI 1.959-10.203; p < 0.001). No significant association was found in European countries.

CONCLUSIONS

This study found evidence of an association between VZV IgG seropositivity and MS in Asian countries. Additional studies are warranted to ascertain factors impacting this association.

Exome-Wide Search for Genes Associated With Central Nervous System Inflammatory Demyelinating Diseases Following CHIKV Infection: The Tip of the Iceberg

Chikungunya virus (CHIKV) is a re-emergent arbovirus that causes a disease characterized primarily by fever, rash and severe persistent polyarthralgia, although <1% of cases develop severe neurological manifestations such as inflammatory demyelinating diseases (IDD) of the central nervous system (CNS) like acute disseminated encephalomyelitis (ADEM) and extensive transverse myelitis. Genetic factors associated with host response and disease severity are still poorly understood. In this study, we performed whole-exome sequencing (WES) to identify HLA alleles, genes and cellular pathways associated with CNS IDD clinical phenotype outcomes following CHIKV infection. The cohort includes 345 patients of which 160 were confirmed for CHIKV. Six cases presented neurological manifestation mimetizing CNS IDD. WES data analysis was performed for 12 patients, including the CNS IDD cases and 6 CHIKV patients without any neurological manifestation. We identified 29 candidate genes harboring rare, pathogenic, or probably pathogenic variants in all exomes analyzed. HLA alleles were also determined and patients who developed CNS IDD shared a common signature with diseases such as Multiple sclerosis (MS) and Neuromyelitis Optica Spectrum Disorders (NMOSD). When these genes were included in Gene Ontology analyses, pathways associated with CNS IDD syndromes were retrieved, suggesting that CHIKV-induced CNS outcomesmay share a genetic background with other neurological disorders. To our knowledge, this study was the first genome-wide investigation of genetic risk factors for CNS phenotypes in CHIKV infection. Our data suggest that HLA-DRB1 alleles associated with demyelinating diseases may also confer risk of CNS IDD outcomes in patients with CHIKV infection.

Identification of hub lncRNA ceRNAs in multiple sclerosis based on ceRNA mechanisms

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system, and the pathogenesis is influenced by genetic susceptibility. Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) play essential roles in complex diseases, including acting as competing endogenous RNAs (ceRNAs). However, the functional roles and regulatory mechanisms of lncRNAs acting as ceRNAs in MS are still unclear. In this study, we identified hub lncRNA ceRNAs in MS based on ceRNA mechanisms and annotated their functions. The lncRNA-associated ceRNA network (LACN) was constructed by integrating the expression profiles of lncRNA/mRNA and miRNA in MS and normal samples, and the experimentally validated interactions of lncRNA-miRNA and mRNA-miRNA. We found three hub lncRNA ceRNAs (XIST, OIP5-AS1, and CTB-89H12.4) using the network analysis and obtained 96 lncRNA-mediated competing triplets (LCTs, lncRNA-miRNA-mRNA) with the hub lncRNA ceRNAs, which constituted 3 hub ceRNA modules. The functional analysis identified 12 pathways enriched by the 3 hub lncRNA ceRNAs, of which 6 were confirmed to be related to MS. For example, XIST was enriched in the 'spliceosome' and 'RNA transport' related to the typing of MS, and CTB-89H12.4 was enriched in the 'mTOR signaling pathway,' a potential therapeutic target for MS. We dissected the expression patterns of the 96 LCTs in MS individually. LCT XIST-miR-326-HNRNPA1, for which the expression pattern in MS revealed that XIST and HNRNPA1 were up-regulated and miR-326 was down-regulated, consisted of risk RNAs for MS that were validated by other research. Therefore, XIST-miR-326-HNRNPA1 might play a central role in the pathogenesis of MS. These results will contribute to the discovery of novel biomarkers and the development of new therapeutic methods for MS.

Prevalence of seropositivity of selected herpesviruses in patients with multiple sclerosis in the North of Jordan

Background

Multiple sclerosis (MS) is a neurological disease that is caused by an autoimmune response that results in the neuron’s demyelination in the central nervous system. The exact etiology of MS is not clear; however, several environmental and genetic factors are believed to participate in its initiation and development, including exposure to viruses. This study aims to investigate the association between the seropositivity and antibody titer of selected herpesviruses and MS in Jordanian MS patients.

Method

In this study, 55 MS patients and 40 age- and gender-matching apparently healthy volunteers were recruited from two main hospitals in the north of Jordan. MS patients were grouped into three types of MS based on the clinical presentation of the disease. Blood samples were collected from the participants and the IgG antibodies for human herpesvirus 6 (HHV-6), Epstein-Barr virus (EBV) nuclear antigen (EBNA), EBV viral capsid antigen (VCA) and varicella-zoster virus (VZV) were assayed by ELISA. The prevalence of seropositivity and the antibody level for each of the antibodies were compared between MS patients and controls and between the three types of MS.

Results

There was no significant difference in the prevalence of seropositivity and in the levels of antibodies for HHV-6, EBNA and VCA between MS patients and controls and between the three types of MS. In contrast, the number of seropositive patients and the level of IgG antibodies for VZV were significantly higher in MS patients compared to the control.

Conclusion

This study showed that patients with MS in the north of Jordan were more likely to be seropositive for VZV than the general population. Based on this finding, we recommend further studies to evaluate the seropositivity to VZV to be carried out in other parts of Jordan and the greater middle east to find out if there is a correlation between MS and previous infection with VZV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-020-01977-w.

In-Depth Bioinformatic Analyses of Nidovirales Including Human SARS-CoV-2, SARS-CoV, MERS-CoV Viruses Suggest Important Roles of Non-canonical Nucleic Acid Structures in Their Lifecycles

Non-canonical nucleic acid structures play important roles in the regulation of molecular processes. Considering the importance of the ongoing coronavirus crisis, we decided to evaluate genomes of all coronaviruses sequenced to date (stated more broadly, the order Nidovirales) to determine if they contain non-canonical nucleic acid structures. We discovered much evidence of putative G-quadruplex sites and even much more of inverted repeats (IRs) loci, which in fact are ubiquitous along the whole genomic sequence and indicate a possible mechanism for genomic RNA packaging. The most notable enrichment of IRs was found inside 5'UTR for IRs of size 12+ nucleotides, and the most notable enrichment of putative quadruplex sites (PQSs) was located before 3'UTR, inside 5'UTR, and before mRNA. This indicates crucial regulatory roles for both IRs and PQSs. Moreover, we found multiple G-quadruplex binding motifs in human proteins having potential for binding of SARS-CoV-2 RNA. Non-canonical nucleic acids structures in Nidovirales and in novel SARS-CoV-2 are therefore promising druggable structures that can be targeted and utilized in the future.