FTY720 treatment reduces T cell infiltration into the CNS of JHMV-infected mice. S1P1 eGFP mice were i.c. infected with JHMV (150 PFU) and treated daily with FTY720 (3 mg/kg) starting on day 5 p.i. (A) Representative flow data and (B) frequencies of CD3+ T cells showing reduced expression of S1P1 (as determined by eGFP expression) in blood at day 7 p.i. (C) Representative flow data showing CD4+ and CD8+ T cell accumulation within the CNS of sham-infected and JHMV-infected eGFP S1P1 mice treated daily with vehicle or FTY720 (3 mg/kg) starting at day 5 p.i. Frequencies of CD4+ (D) and CD8+ T cells (E) present within the brains of either vehicle- or FTY720-treated infected mice as well as sham-infected controls at defined times p.i. Data in panels B, D and E are presented as average + SEM and represent three independent experiments with a minimum of five mice/group. *P <0.05, *** P <0.001. FSC, forward scatter.