Ideally, our immune system functions to protect us from dangerous substances. In MS, however, the immune mistakenly targets the brain and spinal cord, damaging the myelin insulation of nerve fibers. Nerve fibers are damaged as well. "T cells" are a major player in the immune response, so therapeutic strategies that could prevent activation of T cells are key to treating and possibly preventing MS. This grant aims to boost our understanding of the immune attack and chronic damage to nervous system tissue in MS, yielding potential targets for new treatments.