Suppression of experimental allergic encephalomyelitis by intraventricular administration of interferon-gamma in...

Experimental allergic encephalomyelitis (EAE) is an autoimmune inflammatory disease of the central nervous system (CNS) which causes paralysis. Several studies have reported the involvement of Ia antigen-expressing cells in the pathogenesis of EAE. Interferon-gamma (IFN-gamma) can induce Ia antigen expression on a wide range of cells. We examined the effect of IFN-gamma on EAE in Lewis rats. Systemically administered IFN-gamma did not change the disease course of EAE, whereas IFN-gamma applied locally into the ventricular system of the CNS resulted in complete suppression of clinical signs. Furthermore, we found that systemic administration of anti-IFN-gamma just prior to the onset of clinical symptoms resulted in a more severe disease course. We conclude that IFN-gamma is capable of exerting a suppressive action in EAE, possibly through induction of Ia antigen expression or through the induction of suppressive mechanisms locally in the CNS.