
<ArticleTitle>Calcium ionophore: a single reagent for the differentiation of primary human acute myelogenous leukaemia cells towards dendritic cells.</ArticleTitle>
<AbstractText>Blood monocytes and <prot>CD34</prot>(+) haemopoietic progenitor cells, as well as certain leukaemic cell lines, acquire characteristics of mature dendritic cells (DC) after stimulation with calcium ionophore (CI). We studied whether the in vitro treatment of primary human acute myelogenous leukaemia (AML) cells with CI leads to differentiation towards DC. Blast cells derived from nine AML patients were cultured in the presence of either CI or an established differentiation cocktail consisting of <prot>granulocyte-macrophage colony-stimulating factor</prot> plus <prot>interleukin 4</prot> and <prot>tumour necrosis factor-alpha</prot> for 5-7 d. Microscopic examination revealed that under both conditions, AML cells were shifted along the DC pathway. In seven out of nine cases, CI-cultivation led to a higher proportion of cells with dendritic morphology. The percentage of <prot>CD40</prot> and <prot>CD86</prot> expressing cells was significantly increased upon CI treatment compared with cytokine-cultured cells. DC molecules as <prot>CD80</prot> and <prot>CD83</prot> were up-regulated upon calcium mobilization of AML cells in four out of nine samples. In four cases, CI-treated stimulator cells induced an enhanced proliferative allogeneic T-cell response compared with cytokine-treated stimulator cells. In conclusion, these data demonstrate that CI treatment is an alternative in vitro strategy to differentiate human AML cells into DC.</AbstractText>
