Multiple sclerosis (MS) is a chronic, debilitating disease in which the body's immune system attacks the insulation surrounding nerves in the brain and spinal cord. It is an autoimmune disorder in which T cells of the immune system mistakenly attack the protective covering (myelin) that surrounds nerve cells (neurons). Canada has one of the highest rates of multiple sclerosis in the world. The causes and triggers of multiple sclerosis remain incompletely understood. Using a mouse model of MS called EAE, I aim to better understand the function of specific genes that could shape the immune response in MS. The function of helper T cells (CD4+) in MS has been extensively studied. However, while killer T cells (CD8+) play a role in the development of MS, much less is known about their precise function in disease. I have identified two molecules (Bat3 and Serpine1) that influence the function of T cells. While Bat3 enhances T cell inflammation, Serpine1 reduces it. By combining EAE with gene therapy approaches, I will study the role of these two molecules in regulating the disease-causing potential of CD4+ and CD8+ T cells. These studies will help us better understand the complex immune processes that shape MS, a disease that is a significant burden to the Canadian population.