IL-2DT treatment followed by anti–AML-reactive CTLs significantly prolonged the survival of mice with advanced AML. B6 mice (10 mice/group) were injected with 10⁶ C1498FFDsR cells followed by IL-2DT and CTL treatment as described. (A) Dot plots showing depletion of Tregs 1 day after IL-2DT treatment in the liver and spleen of mice. (B-C) Kinetics of Treg depletion by IL-2DT. (D) Combination of IL-2DT and CTL treatment significantly decreased tumor burden 17 and 24 days after tumor injection (■ vs □, P < .01). (E) IL-2DT treatment alone significantly prolonged the survival mice compared with either control mice or mice treated with CTLs alone (▵ vs ■ or ▿, P < .01). Combined IL-2DT and CTLs had superior effect (by log-rank test, P < .005) compared with either control mice or mice receiving IL-2DT or CTLs alone. Representative data from 1 of 3 similar experiments are shown. (F) Combed IL-2DT and CTL treatment promotes anti-AML memory response. Naive C57BL/6 or surviving mice (7-8 mice/group) were challenged with either EL-4 (10⁵/dose) or C1498FFDsR (10⁶/dose) cells. Both naive and surviving mice succumbed to EL-4 challenge. Significant increases in survival were observed only in rechallenged recipients of C1498FFDsR (■ vs ▵, P < .001). Error bars represent SD.