Expanded T lymphocytes in the cerebrospinal fluid of multiple sclerosis patients are specific for Epstein-Barr-virus-infected B cells.

Epstein-Barr virus (EBV) infection has long been associated with multiple sclerosis (MS), but the role of EBV in the pathogenesis of MS is not clear. Our hypothesis is that a major fraction of the expanded clones of T lymphocytes in the cerebrospinal fluid (CSF) are specific for autologous EBV-infected B cells. We obtained blood and CSF samples from eight relapsing-remitting patients in the process of diagnosis. We stimulated cells from the blood with autologous EBV-infected lymphoblastoid cell lines (LCL), EBV, varicella zoster virus, influenza, and candida and sorted the responding cells with flow cytometry after 6 d. We sequenced the RNA for T cell receptors (TCR) from CSF, unselected blood cells, and the antigen-specific cells. We used the TCR Vß CDR3 sequences from the antigen-specific cells to assign antigen specificity to the sequences from the CSF and blood. LCL-specific cells comprised 13.0 ± 4.3% (mean ± SD) of the total reads present in CSF and 13.3 ± 7.5% of the reads present in blood. The next most abundant antigen specificity was flu, which was 4.7 ± 1.7% of the reads in the CSF and 9.3 ± 6.6% in the blood. The prominence of LCL-specific reads was even more marked in the top 1% most abundant CSF clones with statistically significant 47% mean overlap with LCL. We conclude that LCL-specific sequences form a major portion of the TCR repertoire in both CSF and blood and that expanded clones specific for LCL are present in MS CSF. This has important implications for the pathogenesis of MS.

The concentrations of antibodies to Epstein-Barr virus decrease during ocrelizumab treatment.

BACKGROUND: Epstein-Barr Virus (EBV) is strongly associated with multiple sclerosis (MS). After initial infection, EBV maintains a life-long latent infection in B lymphocytes. Depletion of B lymphocytes from the blood with the anti-CD20 antibody ocrelizumab (OCR) markedly reduces disease activity in MS. Our objective was to measure the effect of OCR treatment on the antibody response to EBV and human antigens that are cross-reactive with EBV. METHODS: Blood was collected from MS patients before and during OCR treatment. Antibodies to three EBV antigens (EBNA-1, BFRF3, and gp350) and three human proteins that are cross-reactive with EBV (septin-9, DLST, and HNRNPL) were quantified with Western blots. Antibodies to EBNA-1 and BFRF3 were also quantified with ELISA. RESULTS: Antibodies to the EBV proteins BFRF3 and EBNA-1 measured on Western blot were significantly decreased after 12 months on OCR. Subsequent testing with ELISA confirmed the decrease for both BFRF3 and EBNA-1. With Western blots, there was a trend to decreased antibody response to septin-9 and DLST, but not HNRNPL. Total IgG concentration did not change. CONCLUSION: The antibody response to some EBV antigens decreases in OCR treated patients. The benefit of OCR for MS may be through removal of EBV antigenic stimulus.

Gene expression changes in multiple sclerosis relapse suggest activation of T and non-T cells.

A defining feature of multiple sclerosis (MS) is the occurrence of clinical relapses separated by periods of clinical stability. Better understanding of the events underlying clinical relapse might suggest new approaches to treatment. The objective of this study was to measure changes in the expression of RNA in the blood during relapse. We used microarrays to measure mRNA expression in paired samples from 14 MS patients during clinical relapse and while stable. Seventy-one transcripts changed expression at the P < 0.001 significance level. The most notable finding was decreased expression of transcripts with regulatory function, expressed primarily in non-T cells. These decreased transcripts included the interleukin-1 receptor antagonist, which had a corresponding decrease in the protein concentration in serum. Transcripts with increased expression were expressed primarily in T cells. Pathways analysis suggested involvement of the cytokine network, coagulation and complement cascades, IL-10 signaling and NF-κB signaling. We conclude that there are alterations of mRNA expression in both T cells and non-T cells during MS relapse.

The cellular immune response against Epstein-Barr virus decreases during ocrelizumab treatment.

BACKGROUND: Epstein-Barr Virus (EBV) is strongly associated with multiple sclerosis (MS). After initial infection, EBV maintains a life-long latent infection in B lymphocytes. Depletion of B lymphocytes from the blood with the anti-CD20 antibody ocrelizumab markedly reduces disease activity in MS. Our objective was to measure the effect of ocrelizumab treatment on the cellular immune response to EBV. METHODS: Blood was collected from MS patients before and during ocrelizumab treatment. Peripheral blood mononuclear cells were stimulated with various antigens, and the response was measured using tritiated thymidine for proliferation and ELIspot for number of interferon-γ producing cells. RESULTS: The proliferation to autologous EBV-infected cells (LCL) was decreased after both 6 and 12 months of treatment. The number of interferon-γ producing cells on ELIspot in response to stimulation with either LCL or EBV also decreased. Responses to varicella zoster virus, influenza virus, and a mitogen did not change significantly. CONCLUSION: The cellular immune response to EBV and LCL decreases during treatment with ocrelizumab. The benefit of ocrelizumab for MS may be through removal of EBV antigenic stimulus.

Tumefactive demyelination: Clinical outcomes, lesion evolution and treatments.

OBJECTIVE: Large demyelinating lesions with possible mass effect (tumefactive multiple sclerosis or tumefactive demyelination) can be mistaken for tumour-like space-occupying lesions suggesting a malignant outcome. METHODS: We reviewed our own experience of multiple sclerosis subjects (n = 28) with tumefactive demyelination to determine the relationship between clinical outcomes and lesion evolution, clinical outcomes and their relationship to different therapies. Patients with central nervous system demyelinating disease were identified from our database over the last 10 years. RESULTS: No patient increased in extended disability status scale (EDSS). Overall, lesion regression was associated with improved EDSS. Lesion regression was also associated with therapy versus no therapy. No specific therapy or corticosteroid infusions improved EDSS over the long term. The absence of enhancement on follow up on magnetic resonance imaging portended lesion regression. CONCLUSION: Tumefactive demyelination may predict a more benign overall course and is susceptible to traditional immunomodulatory treatments.

Antibodies to the Epstein-Barr virus proteins BFRF3 and BRRF2 cross-react with human proteins.

We hypothesize that the immune response to Epstein-Barr virus (EBV) drives the autoimmune damage in multiple sclerosis (MS). We investigated whether antibodies to two EBV proteins targeted by MS patients cross-react with self proteins. Using affinity columns, immunoprecipitation, and mass spectrometry, we found that antibodies to the EBV protein BFRF3 cross-react with the cytoplasmic protein septin-9, and antibodies to BRRF2 also bind mitochondrial proteins. Using Western blots and ELISA, we demonstrated that MS patients were more likely to have high levels of antibodies to one or another of these self antigens.

Antibodies specific for Epstein-Barr virus nuclear antigen-1 cross-react with human heterogeneous nuclear ribonucleoprotein L.

Epstein-Barr virus (EBV) is associated with multiple sclerosis (MS), and antibodies to the EBV nuclear antigen-1 (EBNA-1) are consistently increased in MS patients. The hypothesis of this study is that anti-EBNA-1 antibodies cross-react with a self antigen in MS patients. We affinity purified anti-EBNA-1 antibodies from human plasma, used the anti-EBNA-1 to immunoprecipitate antigens from human brain, and identified bound antigens with mass spectrometry. Anti-EBNA-1 consistently bound heterogeneous nuclear ribonucleoprotein L (HNRNPL). We expressed both the long and short isoforms of this protein, and verified with Western blots and ELISA that the long isoform cross-reacts with EBNA-1. Immunohistochemistry demonstrated that anti-EBNA-1 bound to an antigen in the nucleus of cultured rat central nervous system cells. ELISA demonstrated the presence of antibodies to HNRNPL in the plasma of both healthy controls and MS patients, but anti-HNRNPL was not increased in MS patients. We conclude that HNRNPL is an autoantigen which cross-reacts with EBNA-1. The relevance of this autoantigen to MS and other autoimmune diseases remains to be investigated.

The increased antibody response to Epstein-Barr virus in multiple sclerosis is restricted to selected virus proteins.

Multiple sclerosis (MS) is associated with Epstein-Barr virus (EBV) infection, and the antibody response to EBV is reported to be increased in MS. EBV contains multiple antigens, and only a few have been investigated. Our hypothesis is that MS patients will have an increased antibody response to only selected EBV antigens. We used immunoprecipitation and quantitative mass spectrometry to identify candidate EBV antigens. We then measured the antibody response to 10 individual EBV proteins with quantitative ELISA. We found that the antibody response was increased in MS to three of the EBV proteins, but not to the other seven.

Regulation of T-cell activation and migration by the kinase TBK1 during neuroinflammation.

Development of an immune or autoimmune response involves T-cell activation in lymphoid organs and subsequent migration to peripheral tissues. Here we show that T-cell-specific ablation of the kinase TBK1 promotes T-cell activation but causes retention of effector T cells in the draining lymph node in a neuroinflammatory autoimmunity model, experimental autoimmune encephalomyelitis (EAE). At older ages, the T-cell-conditional TBK1-knockout mice also spontaneously accumulate T cells with activated phenotype. TBK1 controls the activation of AKT and its downstream kinase mTORC1 by a mechanism involving TBK1-stimulated AKT ubiquitination and degradation. The deregulated AKT-mTORC1 signalling in turn contributes to enhanced T-cell activation and impaired effector T-cell egress from draining lymph nodes. Treatment of mice with a small-molecule inhibitor of TBK1 inhibits EAE induction. These results suggest a role for TBK1 in regulating T-cell migration and establish TBK1 as a regulator of the AKT-mTORC1 signalling axis.

Epstein-Barr virus and multiple sclerosis: cellular immune response and cross-reactivity.

We investigated T cell immunity to Epstein-Barr virus (EBV) in multiple sclerosis (MS) and assessed cross-reactivity of the anti-EBV cellular response with brain antigens. We measured the proliferation, cytotoxicity, and number of interferon-γ secreting cells following stimulation with autologous EBV-infected lymphoblastoid cell lines (LCL) in MS patients and matched controls. There were no statistically significant differences for any of the measured responses, but there was a trend towards decreased proliferative responses in MS patients. There was no measured cross-reactivity between LCL and brain antigens. We conclude that the cellular immune response against EBV-infected cells is neither increased nor decreased in MS.

Soluble Nogo-A in CSF is not a useful biomarker for multiple sclerosis.

OBJECTIVE: To determine whether the presence of Nogo-A protein in CSF is a useful biomarker for multiple sclerosis (MS). METHODS: We performed Western blots on CSF from patients with MS and controls with the commercially available Nogo-A antibody and secondary antibody used in a prior report. We used densitometry to measure band density on Western blot. Controls included blots without primary antibody, samples without dithiothreitol (DTT), CSF passed through a protein G column, and Western blots with anti-Ig-light chain antibody. IgG concentration in CSF was measured by ELISA. RESULTS: A band at about 25 kD band was detectable in almost all CSF specimens, but was darker in samples from patients with MS. The density relative to a reference sample (mean +/- SD) was 0.84 +/- 0.67 for relapsing MS (n = 17), 1.16 +/- 0.74 for primary progressive MS (n = 11), and 0.49 +/- 0.22 in controls (n = 12). This band was still present when the primary antibody was omitted, but was absent if the sample buffer did not include DTT or if the CSF was first adsorbed with protein G. IgG concentration was higher in MS CSF and correlated closely with the 25 kD band density (r = 0.78). CONCLUSIONS: A 25 kD band is detectable on Western blots stained with Nogo-A antibody in almost all CSF specimens, but is darker in MS specimens. Our results suggest this band is immunoglobulin light chains rather than Nogo-A. It is not likely to be a useful biomarker for multiple sclerosis.

Familial recurrence rates and genetic models of multiple sclerosis.

Susceptibility to multiple sclerosis (MS) is determined by both inherited and non-inherited factors. The importance of genetic factors is demonstrated by the increased risk of disease in relatives of MS patients. Our objective was to determine the implications of the observed familial recurrence risks for the genetic basis of MS. We developed a computer program which calculates recurrence risks for monozygotic (MZ) twins, siblings, and second degree relatives, and used it to calculate recurrence risks for a wide variety of genetic models. We investigated models with different numbers of genes, different patterns of interaction between the genes, and dominant or recessive inheritance. The models that best reproduced the observed values had multiple loci with strongly synergistic interaction and autosomal dominant (AD) inheritance. At least six loci were required, and we found no upper limit on the number of loci. Models with genetic heterogeneity, where only a fraction of the risk loci are required for disease, are possible. In models with large numbers of loci the "abnormal" alleles conferring risk of disease are the most common allele. We conclude that a variety of genetic models with multiple genes, dominant inheritance, and synergistic interaction between risk genes are consistent with the observed familial recurrence rates in MS.