Similar sensitivity of regulatory T cells towards CD95L-mediated apoptosis in patients with multiple sclerosis and healthy individuals

Abstract Impaired suppressive function of CD4 + CD25 high regulatory T cells (T reg ) has been reported as a novel pathogenetic mechanism in Multiple sclerosis (MS). We addressed if high apoptosis sensitivity of MS-T reg could explain this functional T reg defect. T reg from treatment-naive MS patients showed high sensitivity towards CD95Ligand-mediated apoptosis and exhibited enhanced cell death to IL-2 and TCR-signal deprivation. Since susceptibility of T reg to cell death was similar in MS patients and healthy controls, this cannot explain the inhibitory dysfunction of T reg associated with MS. Furthermore, as cell death is not enhanced, therapeutic expansion of MS-T reg in vitro should be a reasonable and novel therapeutic option.