Differential requirements of naive and memory T cells for CD28 costimulation in autoimmune pathogenesis

Experimental autoimmune encephalomyelitis (EAE) is the most extensively studied animal model of the human disease multiple sclerosis (MS). In EAE, CNS demyelination is induced by immunization with myelin proteins or adoptive transfer of myelin-reactive C D ~ +T cells. Since the antigen specificity of the immune response believed to be responsible for the pathology of MS is not well defined, therapies that target aspects of T cell activation that are not antigen specific may be more applicable to the treatment of MS. As a result, understanding the role of costimulatory molecules in the activation of nai've and memory T cells has become an area of extensive investigation. Naive T cells require two signals for activation. Signal one is provided by engagement of the T cell receptor (TCR) with MHCIpeptide complexes and provides antigen specificity to the immune response. The second signal, termed costimulation, is usually provided by B7 molecules on APC to CD28 molecules expressed on T cells and is antigen-independent. This review will discuss our current understanding of costimulation in the induction and perpetuation of EAE, as well as the potential of costimulaton blockade in the treatment of MS

New and Emerging Disease-Modifying Therapies for Relapsing-Remitting Multiple Sclerosis: What is New and What is to Come

The therapeutic landscape for multiple sclerosis (MS) is rapidly changing. Currently, there are eight FDA approved disease modifying therapies for MS including: IFN-β-1a (Avonex, Rebif), IFN-β-1b (Betaseron, Extavia), glatiramer acetate (Copaxone), mitoxantrone (Novantrone), natalizumab (Tysabri), and fingolimod (Gilenya). This review will highlight the experience to date and key clinical trials of the newest FDA approved agents, natalizumab and fingolimod. It will also review available efficacy and safety data on several promising therapies under active investigation including four monoclonal antibody therapies: alemtuzumab, daclizumab, ocrelizumab and ofatumumab and three oral agents: BG12, laquinimod, and teriflunomide. To conclude, we will discuss where each of these new therapies may best fit into treatment algorithms