Relative effectiveness of spinal cord and purified myelin basic protein in producing resistance to experimental allergic encephalomyelitis.

Isolated myelin basic protein (MBP) was less effective than an equivalent amount of spinal cord in inducing protection against experimental allergic encephalomyelitis produced by a challenge of either cord, purified myelin or MBP. Complete protection was only obtained when an MBP challenge was preceded by spinal cord treatment. There was a 100% incidence of disease in the guinea pigs pretreated with MBP before challenge with spinal cord or myelin, but the onset was delayed by 3--4 weeks and the disease was less severe than in the controls. Recurrent disease was seen in some control and pretreated animals challenged with spinal cord but not in animals challenged with MBP.