FTY720 treatment does not impair T cell anti-viral effector function. Representative flow data (A) showing proliferation (CFSE staining) of virus specific CD4+ and CD8+ T cells in response to treatment with FTY720P (100 nM). (B) Exposure to FTY720 does not affect proliferation compared to vehicle-treated controls. Data are presented as average + SEM and represent two independent experiments. (C) Cytokine production by CD4+ and CD8+ T cells obtained from JHMV-infected mice and subsequently stimulated with either matrix (M) glycoprotein 133–144 CD4 immunodominant epitope or spike (S) glycoprotein 510–518 CD8 immunodominant epitope and incubated with or without FTY720P (100 nM) for 48 h, at which point supernatants were collected and indicated cytokine levels determined by ELISA. (D) LDH assay showing target cell lysis (RMA-S cells were pulsed with 5 μM S510-518 peptide) by CD8+ T cells pre-incubated with FTY720P 100 nM or vehicle. LDH release was determined after 4 h incubation at 37°C. Data are representative of two independent experiments and presented as average ± SEM.