Various ‘Dendritic Cell Antigens‘ are Already Expressed on Uncultured Blasts in Acute Myeloid Leukemia and Myelodysplastic Syndromes

Abstract

Individual DCA-expression profiles should be evaluated before culture to evaluate DC counts/subtypes (mature/viableDC, DC(leu)) in individual patients.

Cytokine Release Patterns in Mixed Lymphocyte Culture (MLC) of T-Cells with Dendritic Cells (DC) Generated from AML Blasts Contribute to Predict anti-Leukaemic T-Cell Reactions and Patients’ Response to Immunotherapy

“…DLIs can be applied therapeutically for treatment of relapse after SCT or prophylactically in order to stabilize remissions -indicating again the central role of T-cells (Roddie et al 2006;Barrett & Savani 2006;Schmid et al 2007). For an improvement of therapy of AML-/MDS-pts at relapse after SCT GM-CSF might be applied in the context of DLI in order to facilitate the generation of APC from leukaemic blasts and thereby to increase antileukaemic activities of donor T-cells against myeloid blasts, as already shown by others and us in ex vivo settings (Kufner et al 2005;Kremser et al 2010;Schmid et al 2011;Dreyßig et al 2011). We could already show that compared to 'MNC'-stimulation stimulation of T-cells with 'DC'/DC leu , as effective APCs presenting the complete leukaemic antigenic repertoire, gives rise to a better mediation of an antileukaemic T-cell response in vitro thereby potentially contributing to a better response to DLI after allogeneic SCT in vivo (Kufner et al 2005;Kremser et al 2010;Grabrucker et al 2010;Dreyßig et al 2011;Buhmann et al 2016).…”

“…On average, 16 ± 8% DC (range 10-30%) and 10 ± 10% DC leu (range 5-29%) could be generated from MNC of AML/MDS-pts using the best of the above mentioned converting methods . The criteria for a successful generation of DC and DC leu were percentages above 10% DC and 5% DC leu detected in the suspension after DC generation as postulated previously by us Dreyßig et al 2011). …”

“…DC were generated from blast rich mononuclear cells (MNC) separated from whole blood samples by density gradient centrifugation using Ficoll-Hypaque (Biochrom, Berlin, Germany) with the previously described converting methods MCM-Mimic, Ca-Ionophore and Picibanil as described by us Dreyßig et al 2011). On average, 16 ± 8% DC (range 10-30%) and 10 ± 10% DC leu (range 5-29%) could be generated from MNC of AML/MDS-pts using the best of the above mentioned converting methods .…”

“…Proportions of positive events in defined gates compared with the isotype controls were calculated using Cell Quest software (Becton Dickinson, BD, Heidelberg, Germany). Quantification and characterization of DC and DC leu were performed by Flow cytometry according to our gating strategy already described by former groups (Schmetzer et al 2007;Kremser et al 2010;Liepert et al 2010;Grabrucker et al 2010;Dreyßig et al 2011). Flow cytometric analyses were carried out on day 0 and 10 followed by a functional cytotoxic fluorolysis assay on day 10 as described below.…”

“…We and others could generate leukaemia derived DC (DC leu ) by transforming leukaemic cells from every given AML-patient in vitro directly to mature APC co-presenting 'DC'-typical antigens (DCA, e.g. CD40, CD86) using the best of three previously tested DC-generating methods (Choudhury et al 1999;Stripecke et al 2002;Kremser et al 2010;Dreyßig et al 2011;Schmetzer & Schmid 2012). Accordingly, we could show that autologous T-cells obtained from AML-pts or allogeneic donor T-cells can be stimulated by DC leu resulting in a very efficient lysis of naive blasts.…”