Forget about requiring a rogue virus or some deranged auto immune reaction.
You don't need to inject mouse brains with foreign antigens and create EAE.
Just one bit of blood on brain tissue activates the immune system and creates MS demyelination.
From the Gladstone Institute Press Release:
In the current study, published in Nature Communications, the scientists created a new animal model of disease to determine if BBB (blood-brain barrier) leakage can cause autoimmunity. They discovered that injecting just one drop of blood into the brain set off the brain's immune response, kick-starting a chain reaction that resulted in inflammation and myelin damage.
These findings offer a completely new way of thinking about how the immune system attacks the brain--it puts the blood in the driver's seat of the onset and progression of disease," says senior author Katerina Akassoglou, PhD, a senior investigator at the Gladstone Institutes and professor of neurology at the University of California, San Francisco. "This opens up the possibility for new types of therapies that target blood coagulation factors, upstream of autoimmune processes."