AML cells cultured in the triple cytokine combinations upregulate expression of costimulatory molecules. PBMNC from AML patients were cultured in the triple cytokine cocktail for 14 days. Cells were labeled with fluorescent monoclonal antibodies and analyzed by flow cytometry. (A) Results obtained with the cells of patient 18 cultured for 14 days in Aim-V alone. (B) Cells cultured in GM-CSF, IL-4, and TNF-. (C) Cells cultured in GM-CSF, IL-4, and CD40L. Cells from patients 7 and 10 through 13 were also studied in similar experiments and comparable increases in CD1a and costimulatory molecule expression were observed.