FYI--
http://www.the-scientist.com/blog/display/55517/
Posted by Edyta Zielinska
Researchers have identified a novel mechanism by which immune cells wiggle their way across the blood-brain barrier in diseases such as multiple sclerosis (MS). A type of T-cell involved in autoimmune disease leads the way, entering the brain and perhaps priming the blood-brain barrier's membrane to attract other immune cells -- opening the door for those cells to do their inflammatory damage, according to a study published online yesterday (Mar 22) in Nature Immunology.