Antigen-specific therapy of multiple sclerosis: the long-sought magic bullet.

The adaptive immune response in multiple sclerosis (MS) targets various myelin proteins and even some inducible heat shock proteins. A few attempts have been made to tolerize relapsing-remitting patients with MS to either full-length myelin basic protein or to a key peptide epitope between residues 83-99. These trials have demonstrated that this approach may potentially provide benefit to patients with relapsing- remitting MS. However, manipulation of responses to myelin proteins can have deleterious effects. The immune response to myelin components is positioned at a key tipping point in the pathophysiology of the disease. Clarification of the key target antigens in MS, and better understanding of practical methods to attain tolerance to a wide variety of myelin and neuronal molecules will provide the basis for the ultimately successful antigen specific therapy.