Background:
Dendritic cells (DCs) are increasingly being utilized for anti-cancer immunotherapy. Acute myeloid leukemia (AML) blasts are able to generate leukemia-derived DC. Advances in culture techniques and AML-DC characterization justify possible clinical applications. We investigated the ability of AML, acute lymphoblastic leukemia (ALL) and biphenotypic acute leukemia (BAL) blasts to differentiate into DCs in vitro and the qualified function of the leukemia-derived DCs.
Methods:
Leukemia cells from 11 patients with AML, 3 patients with ALL and 2 patients with BAL were cultured with GM-CSF, IL-4 and with or without SCF. Cultured leukemia cells were evaluated by phenotype, mixed lymphocyte reaction (MLR), cytokine production and cytotoxic T cell (CTL) inducing activity.
Results:
DCs were generated with GM-CSF and IL-4 from the leukemic blasts in 72% of the AML patient cells. MHC class I/II, CD11c and ICAM-1 were highly expressed in the AML-derived DCs. MLR and enzyme linked immunospot (ELISPOT) assays demonstrated that AML-DCs were able to induce T cell proliferation and activation into IFN-γ secreting effector cells. The ALL blasts from two out of three patients differentiated into DCs with MHC class I/II+, CD11c+ only in the presence of GM-CSF, SCF and IL-4 for 14 days.
Conclusion:
These results suggest that functionallyactive DCs can be differentiated from AML blasts using GM-GSF and IL-4 and ALL, BAL blasts were differentiated into DCs only under stem cell-DC culture conditions.

Keywords: Acute leukemia, Acute myeloid leukaemia, Dendritic cells, Immunotherapy