Fig. 2.

Chemotherapy pre-treatment sensitizes AML cells to DNT-mediated cytotoxicity. a AML3 and b KG1a cells were treated with media, 0.25 μg/mL AraC, or 0.4 μg/mL DNR for 24 h before co-culture with DNTs at a 1:1 or 4:1 E:T ratio, respectively. % Specific killing by DNTs was measured by the flow-based killing assay as described in the Methods section. These experiments were repeated 3 times with similar results. c & d Primary AML blasts collected from 13 AML patients were cultured for 24 h in complete media and either 0.25 μg/mL AraC, or 0.4 μg/mL DNR, followed by a 2 h incubation with DNTs at an E:T ratio of 2:1. Percentages of viable c AML cells or d CD34⁺ AML cells were determined by flow cytometry analysis. **, p < 0.01; ***, p < 0.001; ****, p < 0.0001