Induction of synchronized relapses in SJL/J mice with chronic relapsing experimental allergic encephalomyelitis.

Chronic relapsing experimental allergic encephalomyelitis (CR-EAE) was induced in SJL/J mice by two injections of encephalitogenic emulsion. The majority of mice developed multiple relapses from day 22 to day 367 post injection. To induce synchronized relapses a third injection of the encephalitogenic emulsion was given. Almost all mice that received the third injection developed an acute, synchronized relapse with severe clinical signs within 7 to 11 days. Histologically, there was no difference between the lesions in the spontaneous versus the precipitated relapse. CR-EAE in SJL/J mice modified with the third injection offers an advantage of a reproducible and well-timed acute relapse, which allows precise dissection of the immunological events governing spontaneous relapses in chronic EAE.