FTY does not abrogate a GVL effect. Lethally irradiated B6 mice were given BALB/c BM and C1498ff (3 × 104 cells) on day 0. Cohorts received splenocytes (15 × 106) on day 0 and were administered water or FTY daily by oral gavage from day −1 to day 28. Mice were imaged on days 14 and 28 (n = 5 per group) as indicated in “Materials and methods” after injection with luciferin. Identical exposure times were taken for all pictures. Green indicates a greater tumor load than blue. C indicates a control mouse that did not receive C1498ff. A cross indicates that a mouse died. All mice receiving BM and tumor but no spleen died of tumor by day 28. Although spleen infusions protected most mice from widely metastic tumor growth, several mice died of GVHD. Overall tumor incidence for water-treated mice was 1 of 5 versus 3 of 5 for FTY-treated mice.
