THE EFFECTS OF INTERFERON-GAMMA ON THE CENTRAL-NERVOUS-SYSTEM

Interferon-gamma (IFN-gamma) is a pleotropic cytokine released by T-ly mphocytes and natural killer cells. Normally, these cells do not trave rse the blood-brain barrier at appreciable levels and, as such, IFN-ga mma is generally undetectable within the central nervous system (CNS). Nevertheless, in response to CNS infections, as well as during certai n disorders in which the CNS is affected, T-cell traffic across the bl ood-brain barrier increases considerably, thereby exposing neuronal an d glial cells to the potent effects of IFN-gamma. A large portion of t his article is devoted to the substantial circumstantial and experimen tal evidence that suggests that IFN-gamma plays an important role in t he pathogenesis of the demyelinating disorder multiple sclerosis (MS) and its animal model experimental allergic encephalomyelitis (EAE). Mo reover, the biochemical and physiological effects of IFN-gamma are dis cussed in the context of the potential consequences of such activities on the developing and mature nervous systems.