Astrocytes induce several blood-brain barrier properties in non-neural endothelial cells

THE passage of immunocompetent cells across the blood-brain barrier (BBB) i s regulated at the level of the cerebral capillaries which have specific mo rphological and biochemical properties. We have developed and characterized an in vitro model of the BBB using immortalized human endothelial cells (E CV 304) induced by rat astrocytes. In this model, endothelial cells are att ached together by continuous intercellular junctions with numerous tight ju nctions, develop a permeability barrier having a significant transcellular electrical resistance, possess high activities of gamma-glutamyl transpepti dase (gamma-GTP) and express the brain-type glucose transporter 1 (GLUT-1). These parameters are also characteristic of brain capillary endothelial ce lls. Under the culture conditions used, the ECV 304 cells express the inter cellular adhesion molecule-1 (ICAM-1) on the external plasma membrane at co ncentrations which could permit lymphocyte adhesion to be studied. (C) 1999 Lippincott Williams & Wilkins.