Immunomodulatory kits generating leukaemia derived dendritic cells do not induce blast proliferation ex vivo: IPO-38 as a novel marker to quantify proliferating blasts in acute myeloid leukaemia.

(Leukaemia derived) dendritic cells (DC, DCleu) are potent stimulators of anti-leukaemic activity in acute myeloid leukaemia (AML) and can be generated with immunomodulatory kits containing granulocyte-macrophage-colony-stimulating-factor (GM-CSF), prostaglandin-E1 (PGE1), prostaglandin-E2 (PGE2) and/or picibanil (OK-321). Potential adverse effects initiated through kits, especially the proliferation of blasts, must be ruled out to ensure treatment safety. We quantified proliferating blasts with the proliferation markers CD71 and Ki-67 and the novel proliferation marker IPO-38 before and after kit treatment ex vivo. IPO-38 hereby appeared to be the most sensitive marker; a combination with CD71 may add value when assessing proliferation kinetics. Kit treatment did not or only slightly (<5%) induce blast proliferation in most cases. An induction of blast proliferation was only found in single cases and could be compensated by DCleu-induced anti-leukaemic activity in most times. Overall, we appraise kit treatment to be safe in vivo.

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

Dendritic cells (DC) and leukaemia derived DC (DCleu) are potent stimulators of anti-leukaemic activity in acute myeloid leukaemia (AML) and can be generated from mononuclear cells in vitro following standard DC/DCleu-generating protocols. With respect to future clinical applications though, DC/DCleu-generating protocols specifically designed for application in a whole-blood-(WB)-environment must be established. Therefore, we developed ten new DC/DCleu-generating protocols (kits; Kit-A/-C/-D/-E/-F/-G/-H/-I/-K/-M) for the generation of DC/DCleu from leukaemic WB, containing calcium-ionophore, granulocyte-macrophage-colony-stimulating-factor (GM-CSF), tumour-necrosis-factor-alpha, prostaglandin-E1 (PGE1), prostaglandin-E2 (PGE2) and/or picibanil (OK-432). All protocols were evaluated regarding their performance in generating DC/DCleu using refined classification and/or ranking systems; DC/DCleu 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/DCleu from leukaemic WB. Through refined classification and ranking systems, we were able to select Kit-I (GM-CSF + OK-432), -K (GM-CSF + PGE2) and -M (GM-CSF + PGE1) as the most efficient kits in generating (mature) DC/DCleu, 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/DCleu-based anti-leukaemic immunity in a WB-environment in vitro constitutes an important and directive step for translating DC/DCleu-based immunotherapy of AML into clinical application.