Epstein-Barr Virus and memory B-cells in patients with multiple sclerosis 3538

Abstract Description Epstein-Barr Virus (EBV) is a human lymphotropic virus that establishes a latent infection over 90% of the world’s population. Multiple sclerosis (MS) is an autoimmune chronic inflammatory demyelinating disease of the central nervous system, leading to irreversible disabilities. In a large cohort study of young adults in the U.S. military, EBV infection increased the risk of MS by 32-fold. Epidemiological data support EBV as being necessary, but not sufficient, for the development of MS. We hypothesized that EBV-infected memory B-cells are responsible for driving MS disease activity. We therefore aimed to test whether there is evidence of increased ongoing EBV replication in the B-cells and saliva samples of people with MS compared to non-MS participants. The EBV viral load in the saliva and blood compartments was compared using quantitative polymerase chain reaction (qPCR) and digital PCR (dPCR) respectively. In addition, the EBV genome and the antibody biology of the groups was compared by single nucleotide polymorphism (SNP) and B-cell receptor (BCR) repertoire sequence analysis respectively. We found no significant difference in saliva EBV viral load between groups but higher EBV in Memory B-cells compared to naïve B-cells. EBV genomes were similar between groups. Lymphoblastoid cell lines from MS patients were more clonally diverse than non-MS, whereas the reverse was found for PBMC. Funding Sources OSupported by the Horne Family Charitable Foundation Sponsor Code: QMU_RS_HFC Topic Categories Viral Immunology (VIR)