Title: Use of use of dimethyl fumarate for targeting autoimmunity in type 1 diabetes Abstract: Type 1 diabetes (T1D) in an autoimmune disease characterized by T-cell mediated destruction of insulin producing pancreatic beta-cells. Both innate and adaptive innate immunity are involved in this process. Immunotherapies so far have failed to achieve long-lasting effects on islet autoimmunity, so that prevention and reversal of T1D remain an unmet goal. Dimethyl fumarate (DMF) is an FDA-approved treatment for relapsing remitting multiple sclerosis. Multiple sclerosis data in both animal models and human subjects have shown that DMF targets innate and adaptive immune responses through several mechanisms, including the downregulation of aerobic glycolysis in activated myeloid and lymphoid cells (metabolic inhibition). Our preliminary data strongly suggests that DMF is a promising drug for the treatment of islet autoimmunity, and our long-term goal is to launch a clinical trial to test whether DMF preserves insulin secretion in T1D. As a pre-requisite, a clinical trial would have to be supported by preclinical data that demonstrate its efficacy in a disease-relevant model. Thus, the goal of this proposal is to conduct preclinical investigations in the NOD mouse model, a widely accepted model of T1D, to test whether DMF can antagonize autoimmunity at diabetes onset (diabetes reversal). This approach is the directly relevant to the clinical setting, where most new therapies being considered for islet autoimmunity are first tested in clinical trials of patients with recent T1D onset. Therefore, our specific aims are: 1) To fully test the hypothesis that DMF therapy reverses diabetes and obtain definitive reproducible efficacy data in NOD mice; 2) To characterize the effects and mechanisms of action of DMF therapy by studying immune subsets, autoantigen specific responses, pancreas pathology and β-cell function. This study is significant since DMF has not been tested in T1D and yet is appears to possess many desirable properties. The proposed project is also innovative since represents a new approach in treating the disease through a mechanism of action which includes metabolic inhibition. 0

Project narrative: Type 1 diabetes (T1D) is an autoimmune disease where both innate and adaptive immunity are involved in the T-cell mediated destruction of insulin-producing pancreatic beta-cells. Dimethyl fumarate (DMF) was recently approved by the FDA (Tecfidera) for the treatment of relapsing remitting multiple sclerosis and is able to target innate and adaptive immunity. DMF is a promising drug for the treatment of islet autoimmunity and the goal of this proposal is to test the effect of DMF in the NOD mouse model, a widely accepted model of T1D, with the long-term goal of launching a clinical trial.