Methods Mol Med. 2003;89:83-94
Engelhardt B, Vajkoczy P, Laschinger M.
The central nervous system (CNS) is considered to be an immune-privileged site.
Entry of lymphocytes into the CNS is tightly controlled by endothelium, which is an important component of the blood-brain barrier (BBB).
Under physiologic conditions, lymphocyte traffic into the CNS is low, whereas during inflammatory diseases of the CNS such as multiple sclerosis (MS) or in the animal model experimental autoimmune encephalomyelitis (EAE) large numbers of circulating lymphocytes readily gain access to the CNS later during disease facilitated by the loss of BBB integrity.
Thus, the interaction of circulating inflammatory cells with endothelium is a critical step in the pathogenesis of EAE.
In general, lymphocyte recruitment across the vascular wall is regulated by the sequential interaction of different adhesion or signaling molecules on lymphocytes and endothelial cells lining the vessel wall.
An initial transient contact of the circulating leukocyte with the vascular endothelium, generally mediated by adhesion molecules of the selectin family and their respective carbohydrate ligands, slows down the leukocyte in the bloodstream.
Subsequently, the leukocyte rolls along the vascular wall with greatly reduced velocity.