A potential role for CD8+ T-cells as regulators of CNS vascular permeability.

The role of immune cells in promoting central nervous system (CNS) vascular permeability is poorly understood. In recent years, there is a growing body of literature that suggests CD8+ T-cells are potent mediators of vascular permeability in peripheral viral infections as well as in immune mediated neurological diseases. This review outlines the recent advances in tissue culture and animal models used to study vascular permeability. In addition, we put forth our hypothesis that CD8+ T-cells promote the opening of tight junctions between cerebral endothelial cells, enabling the infiltration of white blood cells and in certain models even leading to microhemorrhages in the CNS. Determining the mechanism by which CD8+ T-cells and other immune cells promote CNS vascular permeability in animal models could define new targets for immune mediated neurological conditions characterized by vascular permeability.