Casey M. M. Pfluger

Decreased T cell reactivity to Epstein–Barr virus infected lymphoblastoid cell lines in multiple sclerosis

Objective: To investigate T cell and antibody immunity to Epstein–Barr virus (EBV) in multiple sclerosis (MS). Methods: Immunoglobulin G (IgG) immunity to EBV nuclear antigen 1 (EBNA1) and viral capsid antigen was measured by enzyme linked immunosorbent assays, and T cell immunity was assessed using enzyme linked immunospot assays to measure the frequency of peripheral blood mononuclear cells (PBMC) producing interferon γ in response to autologous EBV infected B cell lymphoblastoid cell lines (LCL) in 34 EBV seropositive healthy subjects and 34 EBV seropositive patients with MS who had not received immunomodulatory therapy in the previous 3 months. Results: Patients with MS had increased levels of anti-EBNA1 IgG but a decreased frequency of LCL specific T cells compared with healthy subjects. Using purified populations of CD4+ T cells and CD8+ T cells, we showed that the LCL specific response resides predominantly in the CD8+ population, with a frequency 5–7-fold higher than in the CD4+ population. The decreased CD8+ T cell response to LCL in MS was not caused by decreased HLA class I expression by LCL, and LCL from MS patients could be killed normally by HLA matched EBV specific cytotoxic CD8+ T cell clones from healthy subjects. Furthermore, the decreased CD8+ T cell immunity to EBV was not due to a primary defect in the function of CD8+ T cells because EBV specific cytotoxic CD8+ T cell lines could be generated normally from the PBMC of patients with MS. Conclusion: This quantitative deficiency in CD8+ T cell immunity to EBV might be responsible for the accumulation of EBV infected B cells in the brains of patients with MS.

Deficiency of CD8 + effector memory T cells is an early and persistent feature of multiple sclerosis

Background: Patients with multiple sclerosis (MS) have a deficiency of circulating CD8+ T cells, which might impair control of Epstein–Barr virus (EBV) and predispose to MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system. Based on the expression of CD45RA and CD62L, CD4+ T cells and CD8+ T cells can be subdivided into four subsets with distinct homing and functional properties, namely: naïve, central memory, effector memory (EM) and effector memory re-expressing CD45RA (EMRA) cells. Objective: Our aim was to determine which memory subsets are involved in the CD8+ T cell deficiency and how these relate to clinical course. Methods: We used flow cytometry to analyze the memory phenotypes of T cells in the blood of 118 MS patients and 112 healthy subjects. Results: MS patients had a decreased frequency of EM (CD45RA–CD62L–) and EMRA (CD45RA+CD62L–) CD8+ T cells, which was present at the onset of disease and persisted throughout the clinical course. The frequencies of CD4+ EM and EMRA T cells were normal. Conclusion: Deficiency of effector memory CD8+ T cells is an early and persistent feature of MS and might underlie the impaired CD8+ T cell control of EBV.

CD8 T cell deficiency impairs control of Epstein–Barr virus and worsens with age in multiple sclerosis

A large body of evidence indicates that infection with the Epstein–Barr virus (EBV) has a role in the pathogenesis of multiple sclerosis (MS).1 We have previously hypothesised that a genetically determined defect in the elimination of EBV-infected B cells by cytotoxic CD8 T cells might predispose to the development of MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system (CNS).1 2 Recently, we have shown that patients with MS have a decreased frequency of CD8 T cells reactive to their own EBV-infected B cells.3 Since 1980, it has been recognised that MS patients have a decreased proportion and number of CD8 T cells in peripheral blood.4 This was initially interpreted as a decrease in CD8 suppressor T cells leading to disinhibition of autoimmune responses but was later attributed to sequestration of CD8 T cells in the CNS. An alternative explanation is that the CD8 T cell deficiency is genetically determined and causes the decreased CD8 T cell response to EBV,3 which allows the accumulation of EBV-infected B cells in the CNS and the consequent development of MS. In the present study, we have used flow cytometry to determine the frequency of CD8 T cells in the blood and its relationship to the EBV-specific T cell response and clinical features of MS. Blood was collected from 64 MS patients and 68 age- and sex-matched healthy subjects after obtaining informed consent. This study was approved by the Royal Brisbane & Womens Hospital …

Altered expression of metabolic proteins and adipokines in patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterized by the loss of upper cortical and lower motor neurons. ALS causes death within 2-5years of diagnosis. Diet and body mass index influence the clinical course of disease, however there is limited information about the expression of metabolic proteins and fat-derived cytokines (adipokines) in ALS. In healthy controls and subjects with ALS, we have measured levels of proteins and adipokines that influence metabolism. We find altered levels of active ghrelin, gastric inhibitory peptide (GIP), pancreatic polypeptide (PP), lipocalin-2, plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6) and 8 (IL-8), and tumor necrosis factor alpha (TNFα) in the plasma of ALS patients relative to controls. We also observe a positive correlation between the expression of plasma nerve growth factor (NGF) relative to disease duration, and an inverse correlation between plasma glucagon and the ALS functional rating scale-revised (ALSFRS-R). Further studies are required to determine whether altered expression of metabolic proteins and adipokines contribute to motor neuron vulnerability and how these factors act to modify the course of disease.

Serial measurements of phosphorylated neurofilament-heavy in the serum of subjects with amyotrophic lateral sclerosis

There is a need for a blood biomarker of disease activity in ALS. This marker needs to measure the loss of motor neurones. Phosphorylated neurofilament heavy chain (pNfH) in the serum is a biomarker of axonal injury. Previous studies have found that levels of pNfH are elevated in ALS. We have performed a serial study of pNfH levels in 98 subjects from our ALS clinic. There was significant elevation of levels of pNfH in subjects with ALS compared to controls, although there was considerable variability. In studies of individuals who had two or more serial samples, we found that the levels of pNfH increased over time in the early stage of disease. Levels were low in subjects with long survival. The rate of rise of pNfH was inversely correlated with survival. We suggest that the initial level of pNfH is a marker of disease severity and that changes in pNfH levels are markers of disease progression.

Decreased CD8+ T cell response to Epstein-Barr virus infected B cells in multiple sclerosis is not due to decreased HLA class I expression on B cells or monocytes

BackgroundPatients with multiple sclerosis (MS) have a decreased frequency of CD8+ T cells reactive to their own Epstein-Barr virus (EBV) infected B cells. We have proposed that this might predispose to the development of MS by allowing EBV-infected autoreactive B cells to accumulate in the central nervous system. The decreased CD8+ T cell response to EBV results from a general CD8+ T cell deficiency and also a decreased proportion of EBV-specific T cells within the total CD8+ T cell population. Because decreased HLA class I expression on monocytes and B cells has been reported in MS and could influence the generation and effector function of EBV-specific CD8+ T cells, the present study was undertaken to measure the expression of HLA molecules on B cells and monocytes in patients with MS.MethodsWe used flow cytometry to determine the proportions of T cells, natural killer cells, B cells and monocytes in peripheral blood mononuclear cells (PBMC) and to quantify the expression of HLA molecules on T cells, B cells and monocytes of 59 healthy subjects and 62 patients with MS who had not received corticosteroids or immunomodulatory therapy in the previous 3 months.ResultsThe levels of HLA class I and class II molecules expressed on T cells, B cells and monocytes were normal in patients with MS, with the exception of two patients with secondary progressive MS with very low class II expression on B cells. In confirmation of previous studies we also found that the percentage of CD8+ T cells was significantly decreased whereas the percentage of CD4+ T cells and the CD4:CD8 ratio were significantly increased in patients with MS compared to healthy subjects.ConclusionsThe decreased CD8+ T cell response to EBV-infected B cells in MS patients is not due to decreased HLA class I expression on monocytes or B cells. In a small proportion of patients decreased HLA class II expression on B cells might impair the CD8+ T cell response to EBV by reducing CD4+ T cell help.

CD8(+) T cells far predominate over CD4(+) T cells in healthy immune response to Epstein-Barr virus infected lymphoblastoid cell lines

To the editor: Infection with EBV is normally kept in check by cellular immunity,[1][1],[2][2] which, if disrupted, may contribute to the important role of EBV in the pathogenesis of certain malignancies[3][3] and possibly chronic autoimmune diseases such as multiple sclerosis and systemic lupus

Whole exome sequencing and DNA methylation analysis in a clinical amyotrophic lateral sclerosis cohort

Gene discovery has provided remarkable biological insights into amyotrophic lateral sclerosis (ALS). One challenge for clinical application of genetic testing is critical evaluation of the significance of reported variants.

Levels of interleukin 33 and soluble suppression of tumorigenicity 2 in acute ischemic stroke

Interleukin 33 (IL‐33) functions as an alarmin and is produced by damaged tissue. It is reported that the levels of both IL‐33 and its receptor, soluble suppression of tumorigenicity 2 (sST2), are elevated in some inflammatory diseases. As acute ischemic stroke causes local inflammation and a systemic immune response, the aim of the present study was to examine the changes of IL‐33 and sST2 serum levels in patients with stroke.

Peripheral immune complement activation in neurodegenerative disease

This free journal suppl. entitled: Special Issue: 25th Biennial Meeting of the International Society for Neurochemistry jointly with the 13th Meeting of the Asian-Pacific Society for Neurochemistry in conjunction with the 35th Meeting of the Australasian Neuroscience Society 23–27 August 2015, Cairns, AustraliaThis free journal suppl. entitled: Special Issue: 25th Biennial Meeting of the International Society for Neurochemistry jointly with the 13th Meeting of the Asian-Pacific Society for Neurochemistry in conjunction with the 35th Meeting of the Australasian Neuroscience Society 23–27 August 2015, Cairns, Australia