Antigen-specific immunosuppression: nasal tolerance to P0 protein peptidesfor the prevention and treatment of experimental autoimmune neuritis in Lewis rats

Experimental autoimmune neuritis (EAN) is an autoimmune inflammatory demyel inating disease of the peripheral nervous system (PNS), and represents an a nimal model of the human Guillain-Barre syndrome (GBS). In this study, we r eport that nasal administration of the neuritogenic peptide 180-199 and of the cryptic peptide 56-71 of the rat neuritogenic PO protein of peripheral nerve myelin prevents EAN and attenuates ongoing EAN. Both peptides effecti vely decreased the severity and shortened clinical EAN. Both a prophylactic and st therapeutic approach proved to be beneficial. These effects were as sociated with T and B cells hyporesponsiveness to the peptide antigens, ref lected by downregulated Th1 cell responses (interferon-gamma secretion) and macrophage function, whereas Th2 cell responses (IL-4 secretion) and trans forming growth factor-beta mRNA expression were upregulated. (C) 1999 Elsev ier Science B.V. All rights reserved.