Reinduction of experimental autoimmune encephalomyelitis in mice.

Experimental autoimmune encephalomyelitis (EAE) in Lewis rats and some strains of mice is typically a monophasic disease, and recovered animals are resistant to reinduction of disease. We demonstrate that SJL mice remain susceptible to disease after recovery, and suffer a second episode of disease when reinjected with spinal cord homogenate in complete Freund's adjuvant. Reinduced disease occurs earlier after injection than the initial disease (mean onset 7.3 days compared with 14.5 days), and has comparable severity and incidence. The susceptibility to reinduced disease is present for at least 20 weeks after the initial injection. If the initial episode of EAE is elicited using a synthetic peptide of proteolipid protein, then reinjection of the same peptide causes reinduced disease. PL/J mice and PL/J x SJL F1 mice are also susceptible to reinduced disease which occurs with an accelerated onset and higher incidence than the initial disease. We conclude that SJL and PL/J mice have a defect in immunoregulation which causes them to be susceptible to recurrent episodes of autoimmune disease.