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

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 8 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 days. 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±standard deviation) 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. Overall design: T cell receptor sequences from cerebrospinal fluid, peripheral blood mononuclear cells (PBMC), and proliferating CD3+ cells from PBMC stimulated with Epstein-Barr virus, autologous EBV-infected cell lines, varicella zoster virus, influenza, or candida.