EBV Mechanism Causing MS PDF

Cool facts about MS and EBV Cool facts about MS and EBV 99.5% of population have EBV Most people get EBV as a child Some can get infectious EBV leading to IM (especially as teens) ~100% of people with MS have had EBV Mechanisms of EBV-Driven MS William Yuan Stephanie Di Guglielmo...

Cool facts about MS and EBV Cool facts about MS and EBV 99.5% of population have EBV Most people get EBV as a child Some can get infectious EBV leading to IM (especially as teens) ~100% of people with MS have had EBV Mechanisms of EBV-Driven MS William Yuan Stephanie Di Guglielmo Jamie Kim  Mechanisms of EBV-Driven MS William Yuan Genetic Susceptibility Stephanie Di Guglielmo Immune Cell Driven Molecular Mimicry Autoimmunity Jamie Kim Could higher genetic susceptibility to EBV translate to increased MS susceptibility?  Hypothesis: Known: HLA-DRB1*15:01 Known: Class 2 allele HLA- increases MS risk: DRB1*15:01 is the it acts as a co- EBV increases the strongest genetic receptor for EBV, risk of MS. risk factor for MS. increasing EBV susceptibility.  Menegatti, J., Schub, D., Schäfer, M., Grässer, F.A. and Ruprecht, K. (2021), HLA-DRB1*15:01 is a co-receptor for Epstein–Barr virus, linking genetic and environmental risk factors for multiple sclerosis. Eur. J. Immunol., 51: 2348-2350. Take human B Transfect cell line Infect transfected lymphoblast cell with HLA- cells with EBV- line 721.174 DRB1*15:01 plasmid GFP The 721.174 cell line is an EBV resistant, HLA class II-negative, CD21+ cell line Infection numbers of transfected cells compared to un-transfected cells, cells transfected with empty plasmids, and cell transfected with the HLA-DRB1*01:01 allele (protective allele) Cells counted with flow cytometry  Findings pSG5 = empty vector Flow cytometry dot plots show one representation of 6 independent experiments with similar results allele protective Untransfected and pSG5 cells show little GFP activation Transfection with either allele made infection possible, with the *15:01 allele showing significantly more infection than the *01:01 allele (p=0.002).  Discussion Results show that HLA-DRB1*15:01 (and HLA-DRB1*01:01) act as coreceptors for EBV on B-cell lines. Mechanistic link between EBV and genetics as MS determinant Suspected that EBV-gp42 (glycoprotein 42) binds to β-1 chain of HLA-DRB1; more efficient binding = higher susceptibility Likely that HLA-DRB1*15:01 has very efficient binding with EBV-gp42 -> increased EBV susceptibility -> increased MS susceptibility Credit: McCarty, S. M., Syed, F., & Bayat, A. (2010). Influence of the Human Leukocyte Antigen Complex on the Development of Cutaneous Fibrosis: An Immunogenetic Perspective. Acta Dermato-Venereologica, 90(6), 563–574. https://doi.org/10.2340/00015555-0975  Is the driver of MS susceptibility more genetic or environmental?  Sundqvist, E., Sundström, P., Lindén, M. et al. Epstein-Barr virus and multiple sclerosis: interaction with HLA. Genes Immun 13, 14–20 (2012). Study: Background: Examine how different quantities of MS patients have EBNA1/EBVNA1 fragments interact with HLA-DRB1*15 and HLA-A*02 more sensitive antibodies against Study based on case-study in Sweden on EBV antigens like general population between ages 16-70. EBNA1 HLA-A*02 is a class I Why? fragment that protects against MS This will let us know if controlling environmental factors is an effective way of EBNA1 (EBV nuclear preventing MS, or if MS development primarily comes down antigen) to a genetic lottery.  Findings When compared to having none of the three risk factors (low EBNA1 IgG quantity, DRB1*15-negative, and A*02 16 x difference positive); having all three risk factors increases risk of MS 16x. High/Low determined by median titre amount in controls. High IgG titres against 385-420 domain had highest increase in risk (OR=3.79, 2.93–4.87 95% CI) Environmental factors are a greater contributor to MS risk than genetics Did we just solve MS? No.  Menegatti, J., Schub, D., Schäfer, M., Grässer, F.A. and Ruprecht, K. (2021), HLA-DRB1*15:01 is a co-receptor for Epstein–Barr virus, linking genetic and environmental risk factors for multiple sclerosis. Eur. J. Immunol., 51: 2348-2350. Study: Meta-analysis on HLA-DRB1*15:01 and EBV on MS across publications on PubMed Web of Science CHKI (China National Knowledge Infrastructure) Wanfan 5 studies out of 659 were deemed eligible  Findings HLA-DRB1*15:01 increased MS (OR=3.06; C.I 95% 2.30-4.08) EBV infection increased MS (OR=2.60; C.I 95% e risk 1.48-4.59) use HLA-DRB1*15:01 + EBV infection had an additive score of 1.43; C.I 95% 1.05-1.95 – insignificant OR of 0.86; C.I 95% 0.59 - 1.26  Discussion Potential Mechanism DRB1*15:01 interferes Limited T-cell In previous study we said that environmental with CD4+ T-cell EBV recognition antigen presentation factors and EBV infection were the main driver of MS; This study says that the HLA-DRB1*15:01 has a greater impact on MS susceptibility. It is possible the reason behind this is the Infected B-cells in CNS previous study looks at the extremes Accumulation of EBV present CNS antigens (above/below the median of control), whereas infected B-cells to CD8+ T-cells the meta-analysis examines the data holistically The extremes of the confidence interval (2.30- 4.08 for genetics; 1.48-4.59 for EBV) would reconcile this perceived inconsistency Autoimmune response MS B Cell Immortalization and Autoimmune Activation of T Cells  Infection of B cells from EBV Viral Proteins EBV infects naïve T cells o CD21 cellular receptors to EBV gp350 Bu, G.-L., Xie, C., Kang, Y.-F., Zeng, M.-S., & Sun, C. (2022). How EBV infects: The tropism and underlying molecular mechanism for viral infection. Kimura, H., Kawada, J., & Ito, Y. (2013). Epstein-Barr virus-associated lymphoid Viruses, 14(11), malignancies: the expanding spectrum of hematopoietic neoplasms. Nayoga 2372. Journal of Medical Science, 75(3-4). https://pubmed.ncbi.nlm.nih.gov/24640173/ https://doi.org/10.3 Immortalization and Proliferation of B cells Latent Membrane Protein 1 (LMP1) o Surrogate signals of costimulatory molecule CD40 > - functional homologue o Induces c-FLIP expression o Upregulate anti-apoptotic factors Latent Membrane Protein 2a (LMP2a) o Mimics BCR signaling o Works with LMP1 to ensure B cell survival IL-10 pathway ↓ CFIP-interferes ws all death pathway Infected Tonsillar Infected Peripheral Infected GC B cells Naïve B cells Memory B cells Modified from: Hatton, O. L., Harris-Arnold, A., Schaffert, S., Krams, S. M., & Martinez, O. M. (2014). Th interplay between Epstein–Barr virus and B lymphocytes: Implications for infection, immunity, and disease. Immunologic Research, 58(2–3), 268–276. https://doi.org/10.1007/s12026-014-8496-1 But how does this relate to MS?  Infected B cells and Autoreactivity 1. 2. EBNA3C-induced AID activation ↓ B cells as main APC for needed for SUM CD4+ T cells and class switching o Infected B cells o Functional Affinity for myelin antigens Kalchschmi dt, J. S., et al. (2016a). Journal of Experiment al Medicine, 213(6), 921– 928. https://doi.o rg/10.1084/j associated to + cells em.201601 may present is - antigens 20 Modified from: Veroni, C., & Aloisi, F. (2021). Frontiers in Immunology, 12. B cells as APCs LMP1 enhances antigen presentation B cells > Dendritic cells o DEC-205 prolonged AP increased MAC class I R&D Systems. https://www.rndsystems.com/resources/articles/dec-205- and-antigen-presentation How do EBV-infected B-cells transmigrate to the CNS? Enhanced chemotaxis via chemoattractants o Increased expression in CSF cerebrospiral fluid > - CXCR5 and CXCL13 upregulated for possible local organization ↓ van Langelaar, J., Rijvers, L., Janssen, M., Wierenga-Wolf, A. F., Melief, M., Siepman, T. A., Lesions may demyelinate MS de Vries, H. E., Unger, P. A., van Ham, S. M., Hintzen, R. Q., & van Luijn, M. M. (2019). Induction of brain-infiltrating t-bet–expressing B cells in multiple sclerosis. Annals of Neurology, 86(2), 264–278. https://doi.org/10.1002/ana.25508 Molecular mimicry How do we know antibodies are important in MS? Increased antibody levels in the CSF Oligoclonal bands – a hallmark of the disease matry autoonebat present What are these antibodies targeting? EBV seems to be a prerequisite for getting MS ~100% of MS patients are infected Anti-EBV antibody levels are higher in MS Self molecules! Modified from: MS Trust. 2022. https://mstrust.org.uk/a-z/lumbar-puncture Nature Genetics. 2018, (50) 699–707. DOI: 10.1038/s41588-018-0102-3  Molecular mimicry Mediated by the Fab region of the antibody Recognizes a viral epitope that is similar to an epitope on a host protein Protein epitope Results in cross-reaction to self proteins/cells v Multiple different epitopes mimicked that might be involved in MS Modified from: Immunapedia. 2024; https://www.immunopaedia.org.za  CovalX. 2024. https://covalx.com/services/epitope-mapping-overview/ EBNA1 EBV nuclear antigen 1 EBV transcription factor EBNA1 Antibodies can be found before symptom onset Associated with increased MS risk Multiple types of antibodies can be generated to EBNA1 AN EXAMPLE: NOT EBNA1 ProImmune. https://www.proimmune.com/b- cell-linear-epitope-mapping/  Amino Acid 441-426 In EAE mice MBP Overview EBNA1 epitope Lanz et. Al 2020 Tengvall et. Al 2019 Thomas et. Al 2023 Amino Acid 394-399 Amino Acid 431-440 Amino Acid 402-406 (Pro-Arg rich region) MS (Pro-Arg rich region) patients ANO2 GlialCAM CRYAB How was this done? Epitope Expose Screen 80% Isolate mapping to the of the human CSF determine to clones proteome to from MS identify to EBV find cross- patients specific lysate reactivity epitopes Identify Identify the Isolate B which Isolate a homologous cell clones specific sequence in clones interact monoclonal the human with the antibody protein lysate  EBNA1 and GlialCAM GlialCAM Immunoglobulin superfamily cell adhesion molecule Expressed by Modified from: Lanz et. Al. (2022). Nature, 603(7900), 321–327. Astrocytes https://doi.org/10.1038/s41586-022-04432-7 Oligodendrocytes (produce myelin) Expressed in plaques in MS brain lesions Cross-reactive antibodies are found in 20-25% of MS patients Due to somatic hypermutation There are many EBNA1 epitopes that cross-react with different GlialCAM epitopes  EBNA1 and GlialCAM: who cares? Immunizing EAE model mice with the EBNA1 epitope results in: Generation of Ab against both EBNA1 and GlialCAM Stimulation of pro-inflammatory cytokines More severe Dx with more demyelination More immune cell infiltration into the CNS Modified from: Lanz et. Al. (2022). Nature, 603(7900), 321–327. https://doi.org/10.1038/s41586-022-04432-7  EBNA1 and Anoctamin 2 (ANO2) increased risk w/ANO2 LuLs ANO2 Ion channel protein Expressed by Neurons Glial cells Expressed in MS plaques ANO2 autoantibodies Increased levels in 14.6% of MS patients Elevated levels even before symptom onset Increase with increased EBNA1 antibody levels These antibodies are associated with high MS risk IF two or more other risk factors are present Modified from: Tengvall et. al. PNAS. 2019, 116 (34); https://doi.org/10.1073/pnas.1902623116 EBNA1 and alpha-crystallin B (CRYAB) CRYAB Heat shock protein Expressed by oligodendrocytes Expressed in MS brain lesions Involved in the regulation of inflammatory responses Increased CRYAB auto-antibodies in 13-27% of patients with all types of MS Increases the risk of MS It’s not just EBNA1 BFRF3 (capsid protein): cross-reacts with septin-9, a cytoplasmic filament protein BRRF2 (nucleocapsid protein): cross-reacts with mitochondrial proteins  Take-home Messages Genetic B-Cell Driven Molecular Mimicry: Susceptibility: Autoimmunity: EBV proteins share homology with different Having certain allele types EBV infects B cells and self-proteins resulting in makes you more or less creates viral proteins to autoimmune activity susceptible to MS. drive cell proliferation and survival. Different patients show DRB1*15:01 is the strongest different patterns of genetic link to MS. Autoimmunity can arise antibody expression through several It is suspected that methods, potentially The presence of these genetics can be linked to targeting MS-associated autoantibodies is linked to EBV-gp42 HLA binding self-antigens. increased MS risk and efficiency and contribute severity to EBV antigen sensitivity Autoimmune EBV- which can lead to higher infected B cells The specific role of these MS risk. transmigrate into CNS to autoantibodies in the induce MS. pathogenesis of MS is still unclear