CD20+inflammatory T-cells are present in blood and brain of multiple sclerosis patients and can be selectively targeted for apoptotic elimination

• Published in: Multiple sclerosis and related disorders 2014-09, Vol.3 (5), p.650-658
• Main Authors: Holley, Janet E, Bremer, Edwin, Kendall, Alexandra C, de Bruyn, Marco, Helfrich, Wijnand, Tarr, Joanna M, Newcombe, Jia, Gutowski, Nicholas J, Eggleton, Paul
• Format: Article
• Language: English
• Subjects: Adult; Antigens, CD20 - immunology; Apoptosis - drug effects; Apoptosis - immunology; Biologics; Brain - drug effects; Brain - immunology; Cells, Cultured; Chronic lesions; Drug Delivery Systems - methods; Female; Human tissue; Humans; Immunosuppressive Agents - therapeutic use; Interleukin-17; Male; Middle Aged; Multiple Sclerosis - blood; Multiple Sclerosis - drug therapy; Multiple Sclerosis - immunology; Neurology; Rituximab - therapeutic use; T-cells; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; T-Lymphocytes - pathology; Treatment Outcome; Young Adult
• ISSN: 2211-0348; 2211-0356
• DOI: 10.1016/j.msard.2014.06.001

Abstract Background A subset of T-cells expresses the B-cell marker CD20 and in rheumatoid arthritis secretes Interleukin (IL)-17. IL-17 secreting T-cells (Th17) have also been implicated in the inflammatory response in the central nervous system in multiple sclerosis (MS) and may be a potential target for elimination by biologic therapeutics. ScFvRit:sFasL comprises of a rituximab-derived antibody fragment scFvRit genetically fused to human soluble FasL that specifically eliminated T-cells. Objective To determine the presence and phenotype of CD20+T-cells in blood and brain of MS patients. Second, to determine whether scFvRit:sFasL can selectively eliminate CD20+T-cells. After CD20-selective binding, scFvRit:sFasL is designed to trigger FasL-mediated activation-induced cell death of T-cells, but not B-cells. Methods Flow cytometry and immunohistochemistry were used to screen for CD20+inflammatory T-cells in MS blood and brain tissue. ScFvRit:sFasL pro-apoptotic activity was evaluated by Annexin-V/PI staining followed by flow cytometry assessment. Results Peripheral blood ( n =11) and chronic but not active lesions of MS patient brains ( n =5) contained CD20+inflammatory T-cells. Activated CD20+T-cells were predominantly CD4+and secreted both IL-17 and INF-γ. ScFvRit:sFasL triggered CD20-restricted FasL-mediated activation-induced cell death in peripheral blood CD20+T-cells, but not CD20+B-cells. Conclusion CD20+inflammatory T-cells are present in blood and chronic brain lesions of MS patients. ScFvRit:sFasL selectively eliminated CD20+T-cells and may eliminate pathogenic T-cells without B-cell depletion.