Transcriptional profile and Epstein-Barr virus infection status of laser-cut immune infiltrates from the brain of patients with progressive multiple sclerosis

Abstract

BackgroundIt is debated whether multiple sclerosis (MS) might result from an immunopathological response toward an active Epstein-Barr virus (EBV) infection brought into the central nervous system (CNS) by immigrating B cells. Based on this model, a relationship should exist between the local immune milieu and EBV infection status in the MS brain. To test this hypothesis, we analyzed expression of viral and cellular genes in brain-infiltrating immune cells.MethodsTwenty-three postmortem snap-frozen brain tissue blocks from 11 patients with progressive MS were selected based on good RNA quality and prominent immune cell infiltration. White matter perivascular and intrameningeal immune infiltrates, including B cell follicle-like structures, were isolated from brain sections using laser capture microdissection. Enhanced PCR-based methods were used to investigate expression of 75 immune-related genes and 6 EBV genes associated with latent and lytic infection. Data were analyzed using univariate and multivariate statistical methods.ResultsGenes related to T cell activation, cytotoxic cell-mediated (or type 1) immunity, B cell growth and differentiation, pathogen recognition, myeloid cell function, type I interferon pathway activation, and leukocyte recruitment were found expressed at different levels in most or all MS brain immune infiltrates. EBV genes were detected in brain samples from 9 of 11 MS patients with expression patterns suggestive of in situ activation of latent infection and, less frequently, entry into the lytic cycle. Comparison of data obtained in meningeal and white matter infiltrates revealed higher expression of genes related to interferonγ production, B cell differentiation, cell proliferation, lipid antigen presentation, and T cell and myeloid cell recruitment, as well as more widespread EBV infection in the meningeal samples. Multivariate analysis grouped genes expressed in meningeal and white matter immune infiltrates into artificial factors that were characterized primarily by genes involved in type 1 immunity effector mechanisms and type I interferon pathway activation.ConclusionThese results confirm profound in situ EBV deregulation and suggest orchestration of local antiviral function in the MS brain, lending support to a model of MS pathogenesis that involves EBV as possible antigenic stimulus of the persistent immune response in the central nervous system.Electronic supplementary materialThe online version of this article (10.1186/s12974-017-1049-5) contains supplementary material, which is available to authorized users.

Epstein–Barr Virus in Multiple Sclerosis: Theory and Emerging Immunotherapies

“…In earlier studies, meningeal B cells within specific structures, referred to as tertiary lymphoid follicles with a GC-like architecture, were described as major sites of EBV persistence in MS brain [46,47]. More recently, the presence of EBV in both MS and healthy brains has been reported [108][109][110]. Veroni [109] identified widespread EBV infection in meninges of MS patients, and EBV-related gene expression profiles (associated with latent EBV infection) in both meningeal and white matter tissue.…”

“…More recently, the presence of EBV in both MS and healthy brains has been reported [108][109][110]. Veroni [109] identified widespread EBV infection in meninges of MS patients, and EBV-related gene expression profiles (associated with latent EBV infection) in both meningeal and white matter tissue. Of further interest was the reported detection of gene expression in EBV-infected cells associated with IFN-g signaling, type I immunity effector functions, B cell differentiation, proliferation, lipid-antigen presentation, and T cell and myeloid cell recruitment.…”

“…Several studies report detection of EBV-infected B cells and plasma cells in the brain of MS patients [30,35,[46][47][48][108][109][110][111]. In earlier studies, meningeal B cells within specific structures, referred to as tertiary lymphoid follicles with a GC-like architecture, were described as major sites of EBV persistence in MS brain [46,47].…”

Integrative analysis of Multiple Sclerosis using a systems biology approach

“…This is likely due to a response further downstream to the infection, and an apparent viral infection by EBV is not the direct causative agent of the changes we observed. Yet there is mounting evidence that MS is tightly linked to EBV infection, whereby viral expression was observed in the CNS of MS cases 27 , 28 . It is also of importance to note that EBV is capable to express latent endogenous retroviral genes in the human genome, some of which are pro-inflammatory and have super-antigenic properties and have been shown to cause neurotoxic effects 29 .…”

Molecular signature of Epstein-Barr virus infection in MS brain lesions

“…MS is a chronic, autoimmune-mediated disorder of the CNS, associated with neurodegeneration and progressive neurologic disability. 1 , 2 Some studies report Epstein-Barr virus (EBV) in MS, 3 – 7 whereas others find no association. 8 , 9 Contradictory results have been attributed to differences in methodology and tissue preservation.…”