An interesting article on Epstein Barr Virus being the cause of MS and how the virus crosses the BBB.
Ashley

In the case of MS, EBV is carried across the blood-brain barrier by lymphocytes B - the cells of the immune system that make anti-bodies, Aloisi said.
"This is an extraordinary result," said ISS President Enrico Garaci.
"For the first time, the observation of a virus in the brain of MS patients has enabled researchers to explain both the characteristics and the mechanisms of the disease".

http://www.ansa.it/site/notizie/awnp...105142211.html