Down-regulation of survivin expression in T lymphocytes after interferon beta-1a treatment in patients with multiple sclerosis.

BACKGROUND: Treatment with interferon beta reduces clinical exacerbations in multiple sclerosis (MS) through several immunomodulatory mechanisms that involve the augmentation of programmed cell death (apoptosis) of peripheral T lymphocytes. The expression of survivin, a cell cycle-regulated antiapoptosis protein, is up-regulated in mitogen-stimulated T lymphocytes from patients with MS, and this expression correlates with MS disease activity.
OBJECTIVE: To evaluate the effect of interferon beta on the expression of survivin and other apoptosis regulatory molecules in peripheral T lymphocytes from patients with MS. PATIENTS AND METHODS: In a prospective, combined clinical and immunologic study, we evaluated the expression of survivin, Bcl-2 protein, and the death receptor Fas in mitogen-stimulated T lymphocytes from 26 patients with MS, before and serially after treatment with interferon beta-1a. We also investigated the long-term effects of interferon beta-1a on cellular expression of these proteins and T-lymphocyte apoptosis in a cross-sectional study of 19 patients with MS receiving long-term interferon beta-1a therapy.
RESULTS: Treatment with interferon beta-1a reduced the expression of survivin in in vitro stimulated T lymphocytes. This reduced expression correlated with augmented T-cell susceptibility to apoptosis and with clinical response to treatment. In contrast, interferon beta-1a therapy did not significantly alter cellular expression of Bcl-2 protein or Fas. This down-regulatory effect of interferon beta-1a on cellular expression of survivin was maintained after long-term therapy.
CONCLUSIONS: Our observations suggest that interferon beta exerts a regulatory effect on peripheral T lymphocytes through an antiapoptosis mechanism that involves the down-regulation of cellular survivin expression.