FTY720 is a prodrug for FTY-phosphate, an agonist at four of the five known 
receptors for sphingosine-1-phosphate (S1P). We show that administration of 
either FTY720 or FTY-P to SJL mice with established relapsing-remitting 
experimental autoimmune encephalitis (EAE) results in a rapid and sustained 
improvement in their clinical status, and a reversal of changes in expression of 
mRNAs encoding some myelin proteins and inflammatory mediators. EAE produced by 
adoptively transferring lymph node cells from immunized mice to naïve hosts is 
similarly ameliorated by FTY-P. Treatment with FTY-P is accompanied by a 
dose-responsive peripheral lymphopoenia.