Tumor-pulsed DCs or Flt3L treatment induces antileukemia immunity in syngeneic BMT recipients.
B6 recipients were lethally irradiated on day −1 and infused with syngeneic B6 BM on day 0. Cohorts of recipients (n = 8-10) received either 3 weekly doses of tumor-pulsed DCs (days 59, 66, and 72), or daily Flt3L injections (day 70 to 91) or no treatment (controls) with lethal (105) C1498 challenge on day 80. (A) A Kaplan-Meier survival plot shows days post-BMT on the x-axis and the proportion surviving on the y-axis. The actuarial survival rate of tumor-pulsed DC or Flt3L recipients was significantly higher (P < .001, P = .01, respectively) than control animals receiving BMT only. (B) On day 80, 2 mice in each group were killed for splenic C1498 leukemia-reactive CTLP frequency estimation. The mean absolute splenic CTLP number ± SD for each group is shown on the y-axis. Significant (P = .01) CTLP increase was detected in the DC-treated group as compared with BMT-only controls or Flt3L-treated mice. Recipients of only syngeneic BMT had significantly (P = .05) lower CTLP frequency than naive animals.
