E- and P-selectin are not involved in the recruitment of inflammatory cells across the blood-brain barrier in experimental autoimmune encephalomyelitis

In experimental autoimmune encephalomyelitis (EAE) inflammatory cells cross the endothelial blood-brain barrier (BBB) and gain access to the central nervous system (CNS). Here we show that E-and P-selectin are not involved in the recruitment of inflammatory cells across the BBB. Neither expression of E-nor P-selectin is induced in BBB-forming endothelium at any time after initiation of EAE. Some of the inflammatory cells present in the CNS during EAE express ligands for E-or P-selectin. However, anti-E-and P-selectin antibodies influence neither immigration of inflammatory cells across the BBB nor the development of EAE, In general, suppression of E-and P-selectin expression on BBB endothelium is dependent on factors derived from the CNS microenvironment, eg, astrocytes. Our results suggest that during EAE suppression of E- and P-selectin expression on the BBB provides a CNS-specific mechanism to reduce leukocyte recruitment into the CNS. (C) 1997 by The American Society of Hematology.