Interferon-beta Mechanisms of Action in Multiple Sclerosis

ABSTRACT Multiple sclerosis (MS) is a chronic autoimmune disease of the CNS characterized by inflammation, demyelination, and axonal injury. These pathologic effects are manifested in clinical symptoms of relapse and disability. Various disease-modifying therapies have been developed in recent years to modulate the body's immune response. Among the most widely used are the beta interferons (IFNbeta). All produce comparable biological effects and are approved for the treatment of relapsing-remitting MS (RRMS). Although the precise mechanisms through which IFNbeta achieves its antiinflammatory and immunomodulatory effects remain uncertain, several modes of action have been proposed, including inhibition of T-cell activation and proliferation; apoptosis of autoreactive T cells; induction of regulatory T cells; inhibition of leukocyte migration across the blood-brain barrier; cytokine modulation; and potential antiviral activity. Endogenously produced IFNbeta in the injured brain is also now believed to contribute to mediation of antiinflammatory and regenerative effects. All these mechanisms are believed to underlie the therapeutic effect of IFNbeta in the treatment of RRMS.