Experimental autoimmune encephalomyelitis (EAE) in mice closely resembles early multiple sclerosis disease pathology. Recently, the laboratory of Dr. Brad E. Hoffman has developed a pre-clinical gene immunotherapy using an adeno-associated virus (AAV) vector that is capable of restoring immune tolerance and abrogate the immune response in myelin oligodendrocyte glycoprotein (MOG) induced EAE by inducing antigen-specific regulatory T cells (Tregs). While the therapy has been shown to prevent and reverse disease, the exact quantity or concentration of antigen-specific Tregs needed to affect disease progression is unknown. The goal of this project is to elucidate the minimum number or concentration of antigen-specific Tregs to effectively suppress disease and restore tolerance. The information gained from the project will give important insight into the robustness of the novel gene therapy and could have future implications of the effective dosage of the therapy.