The development of the immunomodulatory, disease-modifying therapies (DMT) represents a major advance for the treatment of multiple sclerosis (MS). To date, immunomodulatory agents approved for the treatment of MS in the United States include two forms of recombinant interferon-beta (IFN-beta-1a [Avonex, Rebif] and IFN-beta-1b [Betaseron]) and synthetic glatiramer acetate [Copaxone]. These drugs have been shown to favorably alter the natural history of relapsing remitting MS by slowing the progression of disability, reducing relapse rate, and decreasing brain inflammation as measured by MRI. There is evidence that the treatment effects of both IFN-beta and glatiramer acetate are related to their properties in regulating various components of the immune system, in particular, the T cell functions (e.g. proliferation and migratory behavior) and cytokine production.