32Dp210-IL-15/IL-15Rα/CD80 vaccines administered postremission induction have efficacy in eradicating MRD. (A) Leukemic burden of groups 32Dp210-luc-HSV-TK leukemic mice before and after 5 days of GCV treatment destined for postremission vaccination with 32Dp210-IL-15/IL-15Rα/CD80 or no further therapy. Mice were inoculated with 1 × 105 32Dp210 cells on day 0 as indicated by the schema at the top of the figure. On day 10, mice underwent in vivo bioluminescence imaging, and average photon counts per animal were plotted (upper set of bar graphs). N1 to N5 represent normal, non-tumor-bearing mice injected with luciferin on the same day, to establish background luminescence levels. Lanes 1 to 13 indicate mice inoculated with leukemia and subsequently treated with GCV according to the schema at the top of the figure. Blue bars in lanes 1 to 5 indicate analyses of mice that would receive 14 days GCV treatment and no further intervention. Green bars in lanes 6 to 13 depict analyses of mice treated with 14 days of GCV treatment that would undergo serial vaccination with irradiated 32Dp210-IL-15/IL-15Rα/CD80 cells beginning at day 17. Lower panel of bar graphs depicts semiquantitative IVIS studies after 5 days of GCV administration (day 15) in the same animals analyzed in the upper panel of bar graphs. (B) Survival of 32Dp210-luc-HSV-TK leukemia bearing mice after remission induction with GCV treatment is predicated on administration of irradiated 32Dp210-IL-15/IL-15Rα/CD80 vaccine. Purple filled circles: leukemia inoculation with no treatment (n = 5); open circles: 14 days GCV treatment beginning day 10 after leukemia injection with no additional treatment (n = 5); filled green squares: GCV-mediated remission induction followed by serial vaccination with irradiated 32Dp210-IL-15/IL-15Rα/CD80 cells (n = 10).