Activation-induced cell death in T lymphocytes from multiple sclerosis patients.

Apoptosis is a major mechanism regulating immune tolerance by the elimination of autoreactive T lymphocytes. A failure of activation induced cell-death (AICD) has been described in T lymphocytes from patients with multiple sclerosis (MS). The aims of this study were to evaluate AICD in T lymphocytes from patients with MS and healthy controls, and to explore the molecular mechanisms underlying the deregulation observed in apoptosis induction. PHA-induced AICD was reduced in T lymphocytes from patients with relapsing-remitting MS compared with controls. This finding was associated with a diminished expression of Fas and a failure in caspase 3 activation