Infusion of soluble myelin basic protein protects long-term against induction of experimental autoimmune encephalomyelitis.

Protection against experimental autoimmune encephalomyelitis (EAE) induced by s.c. infusion of myelin basic protein (MBP) alone is dose dependent and long lived. Protection is not effective against passively induced disease nor is it transferable with lymphoid cells. The proliferative response of lymph node cells to MBP following encephalitogenic challenge is decreased in the EAE-protected animals as is the production of IL-2 and IFN-gamma by these cells. Treatment with soluble MBP promed rats for antibody production is evidenced by the early appearance of anti-MBP antibody following encephalitogenic challenge. Determination of antibody isotype following challenge revealed a change in the ratio of IgG1 to IgG2a with a significant increase in the amount of IgG1 produced. These data suggest that infusion of high dose soluble neuroantigen primes the immune response such that subsequent challenge with an encephalitogenic inoculum pushes the response down a non-destructive Th2 autoimmune pathway.