Generation of Leukaemia-Derived Dendritic Cells (DC(leu)) to Improve Anti-Leukaemic Activity in AML: Selection of the Most Efficient Response Modifier Combinations

Dendritic cells (DC) and leukaemia derived DC (DC(leu)) are potent stimulators of anti-leukaemic activity in acute myeloid leukaemia (AML) and can be generated from mononuclear cells in vitro following standard DC/DC(leu)-generating protocols. With respect to future clinical applications though, DC/DC(leu)-generating protocols specifically designed for application in a whole-blood-(WB)-environment must be established. Therefore, we developed ten new DC/DC(leu)-generating protocols (kits; Kit-A/-C/-D/-E/-F/-G/-H/-I/-K/-M) for the generation of DC/DC(leu) from leukaemic WB, containing calcium-ionophore, granulocyte-macrophage-colony-stimulating-factor (GM-CSF), tumour-necrosis-factor-alpha, prostaglandin-E(1) (PGE(1)), prostaglandin-E(2) (PGE(2)) and/or picibanil (OK-432). All protocols were evaluated regarding their performance in generating DC/DC(leu) using refined classification and/or ranking systems; DC/DC(leu) were evaluated regarding their performance in stimulating anti-leukaemic activity using a cytotoxicity fluorolysis assay. Overall, we found the new kits capable to generate (mature) DC/DC(leu) from leukaemic WB. Through refined classification and ranking systems, we were able to select Kit-I (GM-CSF + OK-432), -K (GM-CSF + PGE(2)) and -M (GM-CSF + PGE(1)) as the most efficient kits in generating (mature) DC/DC(leu), which are further competent to stimulate immunoreactive cells to show an improved anti-leukaemic cytotoxicity as well. This great performance of Kit-I, -K and -M in mediating DC/DC(leu)-based anti-leukaemic immunity in a WB-environment in vitro constitutes an important and directive step for translating DC/DC(leu)-based immunotherapy of AML into clinical application.