ACTIVATION OF MICROGLIAL AND ENDOTHELIAL-CELLS IN THE RAT-BRAIN AFTERTREATMENT WITH INTERFERON-GAMMA IN-VIVO

Activation of microglial cells occurs during the pathogenesis of vario us neurologic diseases. However, the mechanisms of activation in vivo are still elusive. We infused adult rats intravenously with interferon -gamma and demonstrated microglial cell activation after three days of treatment. We show for the first time that microglial cells prolifera te inside the brain in response to a circulating cytokine. Microglial cells were induced to express major histocompatibility (MHC) class I a nd class II antigens and small amounts of leukocyte function-associate d molecule 1 (LFA-1, CD11a). On endothelial cells of the brain, MHC cl ass I and class II antigens and intercellular adhesion molecule 1 (ICA M-1, CD54) were enhanced. (C) 1997 Wiley-Liss, Inc.