ABSTRACT
Twenty plus years ago, a rapidly growing family of molecules emerged on the scene as secondary mediators of infl ammation. Many of these proteins are produced by immune as well as non-immune cells following exposure to microbial components during infection, or following injury or tissue damage. Many were thought to promote cell migration and recruitment of a wide variety of cells in both the innate and adaptive arms of immunity. These molecules were fi rst identifi ed as secreted basic, heparin binding proteins with the unique ability to attract and activate distinct leukocyte subsets to or at sites of infl ammation as well as to lymphoid organs as regulators of homing. These initial discoveries opened the door for these chemoattractant cytokines-or chemokines-as key regulators of infl ammatory events as well as non-immune cell migration and differentiation in processes of healing and repair. In this chapter, we will primarily review how chemokines and their receptors have been found to infl uence immune cell traffi cking and homeostastis to overcome what is classically considered the immune “privilege” of the central nervous system (CNS) at the blood-brain barrier
1 Department of Pathology and Laboratory Medicine, The University of British Columbia, G227-2211 Wesbrook Mall, Vancouver, Canada, V6T 2B5.
