Three major mechanisms contribute to the pathogenesis of multiple sclerosis (MS): 1) persistent central nervous system (CNS) multifocal inflammation; 2) demyelination and neuron loss; and 3) accumulation of inhibitors of neuroregeneration. Current MS medications target mainly inflammation, and are thus only partially effective. A therapeutic strategy that targets all three mechanisms simultaneously is highly desirable. Neural stem cells (NSCs) can promote multifocal remyelination and functional recovery in experimental autoimmune encephalomyelitis (EAE), an animal model of MS, by cell replenishment and a modest anti-inflammatory effect. Furthermore, NSCs migrate exclusively into inflamed CNS foci upon systemic transplantation, making them a unique tool for delivering therapeutic molecules in situ. Our central hypothesis is that NSCs engineered to produce a cocktail of three therapeutic molecules that target all three main mechanisms of MS pathogenesis will be a novel and highly effective approach in EAE/MS therapy. To test this hypothesis, we will engineer bone marrow (BM)-NSCs to produce IL-10, a potent anti-inflammatory cytokine; NT-3, a potent neurotrophic factor for myelination and neuron survival; and LINGO-1-Fc, a soluble LINGO-1 antagonist that blocks neuroregeneration inhibitors. Their therapeutic effect in chronic and relapsing-remitting EAE and the mechanisms of action in immunomodulation and neural protection will be tested in three specific aims. Additional advantages of this approach include: the intrinsic properties of NSCs for remyelination and neural cell re-population; the ready availability and autologous capacity of BM-NSCs (from patients' own BM), and controllable expression of transduced genes by the Tet-on system. We believe that BM-NSCs engineered to target all three major mechanisms of MS/EAE should pave the way to a novel, easily accessible, autologous, and highly effective MS therapy. PUBLIC HEALTH RELEVANCE: We will modify neural stem cells with a triply effective cocktail to enhance their myelin repair capacity and expect that this approach will more effectively suppress multiple sclerosis (MS). Neural stem cells derived from bone marrow will be used because they are easily accessible and ethically acceptable. Our studies thus may provide a novel and effective approach for MS therapy.