Immediate, long-lasting suppression of autoimmune encephalomyelitis by cell-bound neuroantigen

When lymphoid cells from rats recovered from experimental autoimmune encephalomyelitis (EAE) were incubated in vitro for 1 hr with myelin basic protein (BP), then washed and transferred along with anti-BP immune serum to naive recipients, those recipients immediately developed a solid, long-lasting resistance to active induction of EAE. To obtain this high level of suppression, both steps of BP-incubation of cells and transfer of immune serum were found to be essential, i.e., direct transfer of nonincubated cells plus immune serum had no comparable suppressive effect, nor had transfer of BP-incubated cells with nonimmune serum. Specificity of the suppressive effect was indicated by the finding that cells from BP-sensitized donors, incubated with BP, protected against BP-CFA-induced disease but not against disease induced with whole spinal cord homogenate (SCH-CFA). As expected, cells from SCH-CFA-sensitized donors incubated with SCH protected recipients against disease induced with either SCH-CFA or BP-CFA. The suppression appears to act early in the afferent stage of the immune response, since inoculation with incubated cells as little as 24 hr after active challenge was ineffective. There was no suppression of passively induced disease.