Evaluating the Clinical Utility of Epstein-Barr Virus Antibodies as Biomarkers in Multiple Sclerosis: A Systematic Review.

BACKGROUND: EBV is a necessary but not sufficient factor in the pathophysiology of multiple sclerosis (MS). EBV antibodies to the nuclear antigen (EBNA1) and viral capsid antigen (VCA) rise rapidly prior to MS disease manifestations, and their absence has clinical utility with a high negative predictive value. It remains unclear whether EBV levels act as prognostic, monitoring, or pharmacodynamic/response biomarkers. Substantial literature on this topic exists but has not been systematically reviewed. We hypothesized that EBV levels against EBNA1 and VCA are potential prognostic and monitoring biomarkers in MS, and that patient population, MS clinical phenotype, and EBV assay method may play important roles in explaining variation among study outcomes. METHODS: We systematically searched PubMed and EMBASE from inception to April 1, 2022. After removal of duplicates, records were screened by abstract. Remaining full-text articles were reviewed. Clinical and MRI data were extracted from full-text articles for comparison and synthesis. RESULTS: Searches yielded 696 unique results; 285 were reviewed in full, and 36 met criteria for data extraction. Heterogeneity in sample population, clinical outcome measures, assay methods and statistical analyses precluded a meta-analysis. EBV levels were not consistently associated with clinical disease markers including conversion from CIS to RRMS, neurological disability, or disease phenotype. Studies using repeated-measures design suggest that EBNA1 levels may temporarily reflect inflammatory disease activity as assessed by gadolinium-enhancing Magnetic Resonance Imaging (MRI) lesions. Limited data also suggest a decrease in EBV levels following initiation of certain disease-modifying therapies. CONCLUSION: Heterogeneous methodology limited generalization and meta-analysis. EBV antibody levels are unlikely to represent prognostic biomarkers in MS. The areas of highest ongoing promise relate to diagnostic exclusion and pharmacodynamic/disease response. Use of EBV antibodies as biomarkers in clinical practice remains additionally limited by lack of methodological precision, reliability, and validation.

Humoral response to Epstein-Barr virus in patients with multiple sclerosis treated with B cell depletion therapy.

BACKGROUND: B cell depletion therapy is highly effective in relapsing-remitting multiple sclerosis (RRMS). However, the precise underlying mechanisms of action for its biological effects in MS have still not been clarified. Epstein-Barr virus (EBV) is a known risk factor for MS and seems to be a prerequisite for disease development. EBV resides latently in the memory B cells, and may not only increase the risk of developing MS, but also contribute to disease activity and disability progression. Therefore, the effects of B cell depletion in MS could be associated with the depletion of EBV-infected cells and the altered immune response to the virus. In this study, we investigate the impact of B cell depletion on the humoral immune response specific to EBV in patients with MS. METHODS: Newly diagnosed, treatment-naïve patients with RRMS were followed up to 18 months after initiation of B-cell depletion therapy in the Overlord-MS study, a phase III trial (NCT04578639). We analyzed serum sampled before treatment and after 3, 6, 12 and 18 months for immunoglobulin γ (IgG) against Epstein-Barr nuclear antigen 1 (EBNA1) and Epstein-Barr viral capsid antigen (VCA). We analyzed antibodies to cytomegalovirus (CMV) and total IgG in serum, as controls for viral and overall humoral immunity. The risk allele, HLA-DRB1*15:01, and the protective allele, HLA-A*02:01, were determined in all participants. In addition, polymerase chain reaction (PCR) for circulating EBV-DNA was performed in the first 156 samples drawn. The associations between time on B cell-depletion therapy and serum anti-EBV antibody levels were estimated using linear mixed-effects models. RESULTS: A total of 290 serum samples from 99 patients were available for analysis. After 6, 12 and 18 months, the EBNA1 IgG levels decreased by 12.7 % (95 % CI -18.8 to -6.60, p < 0.001), 12.1 % (95 % CI -19.8 to -3.7, p = 0.006) and 14.6 % (95 % CI to -25.3 to -2.4, p = 0.02) respectively, compared to baseline level. Carriers of the HLA-DRB1*15:01 allele had higher EBNA1 IgG levels at baseline (p = 0.02). The VCA IgG levels significantly increased by 13.7 % (95 % CI 9.4 to 18.1, p < 0.001) after 3 months, compared to baseline, and persisted at this level throughout the follow-up. CMV IgG levels decreased, but to a lesser extent than the decrease of EBNA1 IgG, and total IgG levels decreased during therapy. Circulating EBV-DNA was found in only three of 156 samples from 64 patients. CONCLUSIONS: EBNA1 IgG levels decreased, while VCA IgG levels increased, during B cell depletion therapy. This supports the hypothesis that the mechanism of action for B cell depletion therapy might be mediated by effects on EBV infection, which, in turn, mitigate immune cross-reactivity and disease perpetuation.

Specific antibodies to EBNA1 epitopes as risk factors for multiple sclerosis, a systematic review.

Seroprevalence of anti-EBV antibodies was found to be almost 100% and 90% for multiple sclerosis patients and normal people, respectively. Furthermore, anti EBNA1 antibody which is an indicator of past EBV infection has a higher titer in the serum of Persons with MS (pwMS) compared to the EBV-infected subjects without MS. Though, this difference in anti-EBNA1 antibody titer between pwMS and non-MS controls is not a reliable marker to be used for discriminating pwMS and non-MS individuals. Some Studies have revealed specific epitopes on EBNA1 as the target for anti-EBNA1 antibodies in pwMS. Measuring antibody response against such specific epitopes can help better discriminate pwMS and non-MS individuals. This systematic review aims to obtain conclusive data from the studies which have sought to identify and map such epitopes on EBNA1. Five databases, including PubMed, Google Scholar, web of Science, Scopus, and Elsevier were searched for this purpose. Overall, 12 articles were finally included. Despite different articles describing not exactly the same epitopes, most of the epitopes described are within the amino acid sequence 385-420 of EBNA1. Among these epitopes, most of the epitopes have overlapping amino acid sequences with one another. The most highly overlapping sequence is RRPFF, which encompasses the amino acid 402 to 406 of EBNA1.

Co-infection relationship with Epstein-Barr virus in gastroduodenal diseases with Helicobacter Pylori. Quantitative PCR and EBNA-1 gene-based approach.

Objective: Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) are involved in gastric cancer (GC) etiology. EBV/Hp co- infection was thought synergistically increase gastroduodenal disease occurence. We aimed to determine the presence of EBV/Hp co-infection in gastroduodenal diseases. Methods: The study group had 68 Hp (+) cases [25 GC, 13 IM (intestinal metaplasia), 30 PU (peptic ulcer)], and the control group had 40 NUD (non-ulcer dyspepsia) cases [20 Hp+, 20 Hp-]. EBV-DNA was detected by non-polymorphic EBNA-1 gene-based qPCR. EBV/EBNA-1 IgG levels were determined by quantitative and qualitative ELISA methods, respectively. Results: EBV-DNA positivity was 32% (8/25), 6.6% (2/30) and 5% (1/20) in GC, PU and NUD Hp (+) cases, respectively. There was a significant difference (p = 0.001) between GC (32%) and NUD Hp (+) (5%) cases in terms of EBV-DNA positivity. Mean EBV-DNA copy numbers were 6568.54 ± 20351, 30.60 ± 159.88 and 13.85 ± 61.93 for GC, PU, and NUD, respectively. In terms of the mean EBV-DNA copy number, a significant difference was found between the groups (p = 0.005). In terms of EBV/EBNA-1 IgG antibody positivity, no significant difference was found between GC and NUD cases (p = 0.248). EBV DNA positivity was found to be significant (odds ration [OR] = 26.71 (p=0.009, %95CI 2.286- 312.041) in multivariate logistic regression. Conclusioin: Although we had a small number of GC cases, it can be suggested that the estimated risk created by the synergistic effect based on the addition of EBV increased 26 times in the presence of Hp in GC.

Activation of DNA methyltransferase 3a by Epstein-Barr nuclear antigen 1 in gastric carcinoma.

BACKGROUND: Epstein-Barr nuclear antigen 1 (EBNA1) is expressed in all Epstein-Barr virus (EBV)-infected cells. It interacts with a variety of cellular proteins and activates the transcription of other EBV latency genes, which plays an important role in the persistence of the EBV genome during latent infection. AIM: Several studies have shown that EBV infection induces the expression of DNA methyltransferases (DNMTs) and causes extensive methylation of the whole genome in EBV-associated gastric carcinoma (EBVaGC). However, the specific mechanism by which EBV regulates DNMTs expression is still unclear. METHODS AND RESULTS: EBNA1 plasmid and siRNA were transfected to evaluate the effect of EBNA1 on DNMT3a expression. Molecular biology experiments were used to detect the biological function of DNMT3a and its effect on EBV latency in gastric carcinoma cells. We showed that EBNA1 upregulated DNMT3a expression through the E2F1 transcription factor (E2F1) in EBVaGC. DNMT3a knockdown restrained cell proliferation, induced cell cycle arrest, promoted cell apoptosis and suppressed cell migration in vitro. CONCLUSIONS: Our results showed a new mechanism for EBV to regulate the expression of DNMT3a. Targeting the EBNA1/E2F1/DNMT3a axis may provide an alternative therapeutic strategy in the treatment of EBVaGC with high DNMT3a expression.

Immunogenicity study of engineered ferritins with C- and N-terminus insertion of Epstein-Barr nuclear antigen 1 epitope.

Human ferritin heavy chain, an example of a protein nanoparticle, has recently been used as a vaccine delivery platform. Human ferritin has advantages of uniform architecture, robust thermal and chemical stabilities, and good biocompatibility and biodegradation. There is however a lack of understanding about the relationship between insertion sites in ferritin (N-terminus and C-terminus) and the corresponding humoral and cell-mediated immune responses. To bridge this gap, we utilized an Epstein-Barr Nuclear Antigen 1 (EBNA1) epitope as a model to produce engineered ferritin-based vaccines E1F1 (N-terminus insertion) and F1E1 (C-terminus insertion) for the prevention of Epstein-Barr virus (EBV) infections. X-ray crystallography confirmed the relative positions of the N-terminus insertion and C-terminus insertion. For N-terminus insertion, the epitopes were located on the exterior surface of ferritin, while for C-terminus insertion, the epitopes were inside the ferritin cage. Based on the results of antigen-specific antibody titers from in-vivo tests, we found that there was no obvious difference on humoral immune responses between N-terminus and C-terminus insertion. We also evaluated splenocyte proliferation and memory lymphocyte T cell differentiation. Both results suggested C-terminus insertion produced a stronger proliferative response and cell-mediated immune response than N-terminus insertion. C-terminus insertion of EBNA1 epitope was also processed more efficiently by dendritic cells (DCs) than N-terminus insertion. This provides new insight into the relationship between the insertion site and immunogenicity of ferritin nanoparticle vaccines.

Engineering of Chinese Hamster Ovary Cells With NDPK-A to Enhance DNA Nuclear Delivery Combined With EBNA1 Plasmid Maintenance Gives Improved Exogenous Transient Reporter, mAb and SARS-CoV-2 Spike Protein Expression.

Transient gene expression (TGE) in mammalian cells is a method of rapidly generating recombinant protein material for initial characterisation studies that does not require time-consuming processes associated with stable cell line construction. High TGE yields are heavily dependent on efficient delivery of plasmid DNA across both the plasma and nuclear membranes. Here, we harness the protein nucleoside diphosphate kinase (NDPK-A) that contains a nuclear localisation signal (NLS) to enhance DNA delivery into the nucleus of CHO cells. We show that co-expression of NDPK-A during transient expression results in improved transfection efficiency in CHO cells, presumably due to enhanced transportation of plasmid DNA into the nucleus via the nuclear pore complex. Furthermore, introduction of the Epstein Barr Nuclear Antigen-1 (EBNA-1), a protein that is capable of inducing extrachromosomal maintenance, when coupled with complementary oriP elements on a transient plasmid, was utilised to reduce the effect of plasmid dilution. Whilst there was attenuated growth upon introduction of the EBNA-1 system into CHO cells, when both NDPK-A nuclear import and EBNA-1 mediated technologies were employed together this resulted in enhanced transient recombinant protein yields superior to those generated using either approach independently, including when expressing the complex SARS-CoV-2 spike (S) glycoprotein.

EBNA1 inhibitors have potent and selective antitumor activity in xenograft models of Epstein-Barr virus-associated gastric cancer.

BACKGROUND AND AIMS: Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is the most common EBV-associated cancer and accounts for ~ 10% of all gastric cancers (GC). Epstein-Barr virus nuclear antigen 1 (EBNA1), which is critical for the replication and maintenance of the EBV latent genome, is consistently expressed in all EBVaGC tumors. We previously developed small molecule inhibitors of EBNA1. In this study, we investigated the efficacy and selectivity of an EBNA1 inhibitor in cell-based and animal xenograft models of EBV-positive and EBV-negative gastric carcinoma. METHODS: We tested the potency of an EBNA1 inhibitor, VK-1727, in vitro and in xenograft studies, using EBV-positive (SNU719 and YCCEL1) and EBV-negative (AGS and MKN74) GC cell lines. After treatment, we analyzed cell viability, proliferation, and RNA expression of EBV genes by RT-qPCR. RESULTS: Treatment with VK-1727 selectively inhibits cell cycle progression and proliferation in vitro. In animal studies, treatment with an EBNA1 inhibitor resulted in a significant dose-dependent decrease in tumor growth in EBVaGC xenograft models, but not in EBV-negative GC xenograft studies. Gene expression analysis revealed that short term treatment in cell culture tended towards viral gene activation, while long-term treatment in animal xenografts showed a significant decrease in viral gene expression. CONCLUSIONS: EBNA1 inhibitors are potent and selective inhibitors of cell growth in tissue culture and animal models of EBV-positive GC. Long-term treatment with EBNA1 inhibitors may lead to loss of EBV in mouse xenografts. These results suggest that pharmacological targeting of EBNA1 may be an effective strategy to treat patients with EBVaGC.

Abrogation of USP7 is an alternative strategy to downregulate PD-L1 and sensitize gastric cancer cells to T cells killing.

Targeting immune checkpoints such as programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved for treating melanoma, gastric cancer (GC) and bladder cancer with clinical benefit. Nevertheless, many patients failed to respond to anti-PD-1/PD-L1 treatment, so it is necessary to seek an alternative strategy for traditional PD-1/PD-L1 targeting immunotherapy. Here with the data from The Cancer Genome Atlas (TCGA) and our in-house tissue library, PD-L1 expression was found to be positively correlated with the expression of ubiquitin-specific processing protease 7 (USP7) in GC. Furthermore, USP7 directly interacted with PD-L1 in order to stabilize it, while abrogation of USP7 attenuated PD-L1/PD-1 interaction and sensitized cancer cells to T cell killing in vitro and in vivo. Besides, USP7 inhibitor suppressed GC cells proliferation by stabilizing P53 in vitro and in vivo. Collectively, our findings indicate that in addition to inhibiting cancer cells proliferation, USP7 inhibitor can also downregulate PD-L1 expression to enhance anti-tumor immune response simultaneously. Hence, these data posit USP7 inhibitor as an anti-proliferation agent as well as a novel therapeutic agent in PD-L1/PD-1 blockade strategy that can promote the immune response of the tumor.

The Epstein-Barr Virus-Encoded EBNA1 Protein Activates the Bone Morphogenic Protein (BMP) Signalling Pathway to Promote Carcinoma Cell Migration.

The Epstein-Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) protein is expressed in all virus-associated malignancies, where it performs an essential role in the maintenance, replication and transcription of the EBV genome. In recent years, it has become apparent that EBNA1 can also influence cellular gene transcription. Here, we demonstrate that EBNA1 is able to stimulate the expression of the Transforming growth factor-beta (TGFß) superfamily member, bone morphogenic protein 2 (BMP2), with consequential activation of the BMP signalling pathway in carcinoma cell lines. We show that BMP pathway activation is associated with an increase in the migratory capacity of carcinoma cells, an effect that can be ablated by the BMP antagonist, Noggin. Gene expression profiling of authentic EBV-positive nasopharyngeal carcinoma (NPC) tumours revealed the consistent presence of BMP ligands, established BMP pathway effectors and putative target genes, constituting a prominent BMP "signature" in this virus-associated cancer. Our findings show that EBNA1 is the major viral-encoded protein responsible for activating the BMP signalling pathway in carcinoma cells and supports a role for this pathway in promoting cell migration and possibly, metastatic spread.

Biophysical Screens Identify Fragments That Bind to the Viral DNA-Binding Proteins EBNA1 and LANA.

The human gamma-herpesviruses Epstein-Barr virus (EBV) (HHV-4) and Kaposi's sarcoma-associated herpesvirus (KSHV) (HHV-8) are responsible for a number of diseases, including various types of cancer. Epstein-Barr nuclear antigen 1 (EBNA1) from EBV and latency-associated nuclear antigen (LANA) from KSHV are viral-encoded DNA-binding proteins that are essential for the replication and maintenance of their respective viral genomes during latent, oncogenic infection. As such, EBNA1 and LANA are attractive targets for the development of small-molecule inhibitors. To this end, we performed a biophysical screen of EBNA1 and LANA using a fragment library by saturation transfer difference (STD)-NMR spectroscopy and surface plasmon resonance (SPR). We identified and validated a number of unique fragment hits that bind to EBNA1 or LANA. We also determined the high-resolution crystal structure of one fragment bound to EBNA1. Results from this screening cascade provide new chemical starting points for the further development of potent inhibitors for this class of viral proteins.

Molecular detection of Epstein-Barr virus in different types of lymphoma.

Epstein-Barr virus (EBV) is a member of the γ herpesvirus subfamily. It is widely spread, potentially oncogenic and has been studied in different human cancers such as gastric carcinoma, nasopharyngeal carcinoma and both Hodgkin's and non-Hodgkin's lymphomas. EBV replicates in the oral epithelium, and resting B lymphocytes trafficking through the pharynx develop a latent infection in which only EBV genes related to the B cell growth program are expressed: LMP1, -2a/b, BARTs, EBERs and EBNAs. EBNA1 binds a specific DNA sequence in the viral genome responsible for episome replication, segregation and persistence of the viral genome, and is involved in p53 degradation and oncogenesis. It is also involved in p53 degradation and oncogenesis. Since EBV infection is associated with the progression of malignancy in lymphoma, we used EBNA1-based PCR to determine the frequency of EBV infection in lymphoma specimens from patients with different types of lymphomas. Biopsies from lymphoma patients obtained from National Cancer Institute, Misurata and Tripoli Medical Centre (Libya) showed the presence of EBV in 31 of 40 cases (77%). EBV infection rates did not differ significantly between Hodgkin's lymphoma, and non-Hodgkin's lymphoma. The rates did not vary significantly between the sexes or age groups.

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

Multiple sclerosis (MS) is associated with Epstein-Barr virus (EBV) infection. A characteristic feature of MS is an intrathecal synthesis of immunoglobulin (Ig)G. In 90 patients with clinically isolated syndromes/early relapsing-remitting MS, serum antibodies to Epstein-Barr nuclear antigen-1, but not to EBV viral capsid antigen, rubella, or varicella zoster virus, were higher (p=0.03) in those with than those without a calculated intrathecal IgG synthesis >0% and correlated with the percentage (r=0.27, p=0.009) and concentration (r=0.27, p=0.012) of intrathecally produced IgG. These findings suggest a link between EBV infection and the events leading to intrathecal IgG synthesis in patients with MS.

Differentiation of blood T cells: Reprogramming human induced pluripotent stem cells into neuronal cells.

BACKGROUND: Human induced pluripotent stem cells (iPSCs) morphologically and functionally resemble human embryonic stem cells, which presents the opportunity to use patient-specific somatic cells for disease modeling and drug screening. In order to take one step closer to clinical applications, it is important to generate iPSCs through a less invasive approach and from any accessible tissue, including peripheral blood. Meanwhile, how to differentiate blood cell-derived iPSCs into neuron-like cells is still unclear. METHODS: We utilized Epstein-Barr nuclear antigen-1-based episomal vectors, a nonviral system that can reprogram somatic cells into iPSCs in both feeder-dependent and feeder-free conditions, to generate iPSCs from T cells via electroporation and then induce them into neuronal cells. RESULTS: We successfully isolated sufficient T cells from 20 mL peripheral blood of the donors and reprogrammed these T cells into iPSCs within 4 weeks. These iPSCs could be stably passaged to at least 50 passages, and exhibited the abilities of pluripotency and multiple-lineage differentiation. Notably, under the medium induction for 21 days, these T-cell-derived iPSCs could be differentiated into Nestin (neural progenitor marker)-, GFAP (glial cell marker)-, and MAP2 (neuron cell marker)-positive cells detected by immunofluorescence methods. CONCLUSION: We have developed a safer method to generate integration-free and nonviral human iPSCs from adult somatic cells. This induction method will be useful for the derivation of human integration-free iPSCs and will also be applicable to the generation of iPSCs-derived neuronal cells for drug screening or therapeutics in the near future.

The beneficial effects of vitamin D3 on reducing antibody titers against Epstein-Barr virus in multiple sclerosis patients.

Recently, the relationship between immunoreactivity to Epstein-Barr virus (EBV) and hypo-vitamin D in multiple sclerosis (MS) patients has been described. The aim of this study was to investigate whether vitamin D3 supplementation in MS patients could influence the immune response against latent EBV infection. Forty MS patients were recruited in this study. Twenty-seven patients were supplemented with 50,000 IU/week of vitamin D3 for 6 months and thirteen enrolled as controls. 25-Hydroxyvitamin D (25OHD) levels and IgG titers against EBNA1 and VCA were determined pre- and post-supplementation. All the patients were seropositive for EBV prior to vitamin D supplementation. In this cohort, 22.5% and 47.5% of the MS patients had deficient and insufficient levels of 25OHD, respectively. Our findings confirm that antibody titers against EBV in MS patients rise after the onset of the disease and indicate that vitamin D3 supplementation could limit augmentation of these titers in MS patients.

Conversion from clinically isolated syndrome to multiple sclerosis: A large multicentre study.

BACKGROUND AND OBJECTIVE: We explored which clinical and biochemical variables predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) in a large international cohort. METHODS: Thirty-three centres provided serum samples from 1047 CIS cases with at least two years' follow-up. Age, sex, clinical presentation, T2-hyperintense lesions, cerebrospinal fluid (CSF) oligoclonal bands (OCBs), CSF IgG index, CSF cell count, serum 25-hydroxyvitamin D3 (25-OH-D), cotinine and IgG titres against Epstein-Barr nuclear antigen 1 (EBNA-1) and cytomegalovirus were tested for association with risk of CDMS. RESULTS: At median follow-up of 4.31 years, 623 CIS cases converted to CDMS. Predictors of conversion in multivariable analyses were OCB (HR = 2.18, 95% CI = 1.71-2.77, p < 0.001), number of T2 lesions (two to nine lesions vs 0/1 lesions: HR = 1.97, 95% CI = 1.52-2.55, p < 0.001; >9 lesions vs 0/1 lesions: HR = 2.74, 95% CI = 2.04-3.68, p < 0.001) and age at CIS (HR per year inversely increase = 0.98, 95% CI = 0.98-0.99, p < 0.001). Lower 25-OH-D levels were associated with CDMS in univariable analysis, but this was attenuated in the multivariable model. OCB positivity was associated with higher EBNA-1 IgG titres. CONCLUSIONS: We validated MRI lesion load, OCB and age at CIS as the strongest independent predictors of conversion to CDMS in this multicentre setting. A role for vitamin D is suggested but requires further investigation.

Multiple sclerosis: the elevated antibody response to Epstein-Barr virus primarily targets, but is not confined to, the glycine-alanine repeat of Epstein-Barr nuclear antigen-1.

Patients with multiple sclerosis (MS) have elevated antibodies against Epstein-Barr virus (EBV), but data on the epitope-resolved specificity of these antibodies are scarce. Using a peptide microarray containing 1465 peptides representing 8 full-length EBV proteins, we identified higher (p<0.001) antibody reactivities to 39 EBV-peptides in MS patients (n=29) compared to healthy controls (n=22). Seventeen of the 39 peptides were from EBNA-1 and 13 located within the glycine-alanine repeat of EBNA-1. Further reactivities were directed against EBNA-3, EBNA-4, EBNA-6, VP26, and LMP1. Thus, antibodies against EBV in MS patients primarily target, but are not confined to, the glycine-alanine repeat of EBNA-1.

Vitamin D in autoimmune liver disease.

The development of autoimmune disease is based on the interaction of genetic susceptibility and environmental causes. Environmental factors include infectious and non-infectious agents, with some of these factors being implicated in several autoimmune diseases. Vitamin D is now believed to play a role in the development (or prevention) of several autoimmune diseases, based on its immunomodulatory properties. As well, the increasing incidence of autoimmune disease as one moves away from the equator, may be due to the lack of sunlight, which is crucial for the maintenance of normal vitamin D levels. A deficiency in vitamin D levels or vitamin D receptors is commonly indicated in autoimmune diseases, with multiple sclerosis (MS) being one of the best-studied and well-known examples. However, the role of vitamin D in other autoimmune diseases is not well defined, including autoimmune liver diseases such as primary biliary cirrhosis, autoimmune hepatitis, and primary sclerosing cholangitis. This review will examine the role of vitamin D as an immunomodulator, followed by a comparison of vitamin D in MS versus autoimmune liver disease. From this comparison, it will become clear that vitamin D likely plays a role in the development of autoimmune liver disease, but this area requires further investigation.

Epstein-Barr virus antibodies and vitamin D in prospective multiple sclerosis biobank samples.

BACKGROUND: The antibody reactivity against Epstein-Barr nuclear antigen-1 (EBNA-1), and 25-hydroxyvitamin D (25(OH)D) status have been associated with multiple sclerosis (MS) risk. Interaction between these two factors has been proposed. OBJECTIVES: The objective of this paper is to examine the association between antibody reactivity against EBNA-1 and five EBNA-1 domains, and the risk of MS, and to examine if these antibodies and 25(OH)D status interact regarding MS risk in prospectively collected blood samples. METHODS: Antibody reactivity and 25(OH)D levels were measured using ELISAs in n = 192 MS cases and n = 384 matched controls. The risk of MS was analysed using matched logistic regression. Interaction on the additive scale was assessed. RESULTS: The risk of MS increased across tertiles of antibody reactivity against EBNA-1, domain EBNA-1(402-502), and domain EBNA-1(385-420); p trends < 0.001. In young individuals (below median age at sampling, < 26.4 years), these associations were stronger, and 25(OH)D levels correlated inversely to antibody reactivity against EBNA-1 and the EBNA-1 domains. No statistical interaction was found. CONCLUSIONS: We confirm that increased antibody reactivity against EBNA-1 is a risk factor of MS. 25(OH)D status might influence the immune response towards Epstein-Barr virus in young subjects, and thereby modulate MS risk.