COMPLEXITIES OF APPLYING NASAL TOLERANCE INDUCTION AS A THERAPY FOR ONGOING RELAPSING EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS (EAE) IN DARATS

EAE is an autoimmune disease of the central nervous system (CNS) that serves as an experimental model for the human inflammatory demyelinati ng disease multiple sclerosis (MS). Antigen-based immunotherapy includ ing soluble antigen administration via feeding has been shown to be su ccessful in treating EAE in rodents. In the present study, we explore nasal administration of small amounts of myelin basic protein (MBP) as a potential means of treatment of protracted, relapsing EAE (PR-EAE) in a novel DA rat system. We found that nasal administration of MBP pr evented EAE induced with whole spinal cord homogenate + Freund's incom plete adjuvant (FIA), and strongly down-regulated levels of MBP-reacti ve interferon-gamma (IFN-gamma)-secreting Th1-like cells. However, in rats with ongoing PR-EAE receiving the same regimen of MBP, a trend of aggravated disease was recorded, in conjunction with augmented levels of MBP-reactive IFN-gamma-secreting Th1-like splenocytes during the a cute phase of EAE. These data have implications for the clinical appli cation of nasal tolerance to autoimmune diseases.