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

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 treatmentnaive 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. (c) 2006 Elsevier B.V. All rights reserved.