Abstract
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS), the etiology of which is poorly understood. The most common laboratory abnormality associated with MS is increased intrathecal immunoglobulin G (IgG) synthesis and the presence of oligoclonal bands (OCBs) in the brain and cerebrospinal fluid (CSF). However, the major antigenic targets of these antibody responses are unknown. The risk of MS is increased after infectious mononucleosis (IM) due to EBV infection, and MS patients have higher serum titers of anti-EBV antibodies than control populations. Our goal was to identify disease-relevant epitopes of IgG antibodies in MS; to do so, we screened phage-displayed random peptide libraries (12-mer) with total IgG antibodies purified from the brain of a patient with acute MS. We identified and characterized the phage peptides for binding specificity to intrathecal IgG from patients with MS and from controls by ELISA, phage-mediated Immuno-PCR, and isoelectric focusing. We identified two phage peptides that share sequence homologies with EBV nuclear antigens 1 and 2 (EBNA1 and EBNA2), respectively. The specificity of the EBV epitopes found by panning with MS brain IgG was confirmed by ELISA and competitive inhibition assays. Using a highly sensitive phage-mediated immuno-PCR assay, we determined specific bindings of the two EBV epitopes to IgG from CSF from 46 MS and 5 inflammatory control (IC) patients. MS CSF IgG have significantly higher bindings to EBNA1 epitope than to EBNA2 epitope, whereas EBNA1 and EBNA2 did not significantly differ in binding to IC CSF IgG. Further, the EBNA1 epitope was recognized by OCBs from multiple MS CSF as shown in blotting assays with samples separated by isoelectric focusing. The EBNA1 epitope is reactive to MS intrathecal antibodies corresponding to oligoclonal bands. This reinforces the potential role of EBV in the etiology of MS. Graphical abstractAntibodies purified from an MS brain plaque were panned by phage display peptide libraries to discern potential antigens. Phage displaying peptide sequences resembling Epstein-Barr Virus Nuclear Antigens 1 & 2 (EBNA1 & 2) epitopes were identified. Antibodies from sera and CSF from other MS patients also reacted to those epitopes. Electronic supplementary materialThe online version of this article (10.1007/s11481-020-09948-1) contains supplementary material, which is available to authorized users.
Highlights
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by demyelination and gliosis, with various degrees of axonal pathology and episodic or progressive neurological disability (Compston and Coles, 2008)
In MS patients, longitudinal analyses of serum samples collected more than 10 years before the onset of clinical symptoms consistently showed that the risk of developing the disease increased significantly with the level of Epstein-Barr virus (EBV) antibody titers, with the strongest association being found for immunoglobulin G (IgG) antibodies binding to an EBV latent antigen, nuclear antigen 1 (EBNA1) (Ascherio et al, 2001; Levin et al, 2005; DeLorenze et al, 2006)
We have shown in this study that phage peptides discovered by panning with IgG antibodies derived from a lesion in an acute MS brain (MS 95–2 IgG) shared high sequence and putative structural homologies with Epstein-Barr virus antigens EBNA1 and EBNA2
Summary
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by demyelination and gliosis, with various degrees of axonal pathology and episodic or progressive neurological disability (Compston and Coles, 2008). A persistent synthesis of IgG antibodies (manifested as oligoclonal bands) in the cerebrospinal fluid (CSF) and brain is an immunological hallmark usually seen in MS (Compston and Coles, 2008). In MS patients, longitudinal analyses of serum samples collected more than 10 years before the onset of clinical symptoms consistently showed that the risk of developing the disease increased significantly with the level of EBV antibody titers, with the strongest association being found for IgG antibodies binding to an EBV latent antigen, nuclear antigen 1 (EBNA1) (Ascherio et al, 2001; Levin et al, 2005; DeLorenze et al, 2006). EBNA1, the crucial EBV antigen for latency of the virus, constitutes a dominant antigen for both humoral and cell-mediated immune responses to the virus, and the deregulation of EBV-specific immunity in MS has been reported primarily for this antigen (Lunemann et al, 2007)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
