Fig. 1.

a Blast count change in BM of patients during therapy. Maximal change of BM blast count (%) from baseline of available patients who reached response assessment after 3 months of TAL treatment (n = 10). b Distribution of mature NK cells in patients compared with HC. At baseline, patients expressed lower levels of CD56dim NK cells compared with HC in PB. (p = 0.065) (pretreatment (pre); posttreatment (post)), patients n = 24, HC = 24. c Expression of PD-1 on lymphocytes in patients compared to HC. During screening, expression of PD-1 on lymphocytes in PB was significantly higher in patients compared to HC. patients n = 24, HC = 24. d Expression of PD-L1 on blasts in patients compared with HC. Expression of the corresponding ligand PD-L1 on blasts was significantly higher in patients than in HC. patients n = 24, HC = 24. e Expression of CD123 on iMDSCs in patients compared with HC. Pre treatment expression (percentage) of CD123 on immature MDSC (iMDSC) was higher in HC than in patients. A reduction of CD123+ iMDSC (p = 0.07) was detected during treatment. We determined iMDSC as LIN−, HLA-DR−, CD11b+, and CD33+. Patients baseline n = 24, HC n = 24, patients post treatment n = 10. Analysis for patients pre and post treatment was undertaken with those patients who reached three months of therapy (n = 10). f Expression of CD123 on BM blasts in patients compared with HC. Patients showed higher expression (MFI) of CD123 on BM blasts compared with HC. Under treatment, those MFI levels showed a nonsignificant reduction. (pretreatment (pre); posttreatment (post)) patients n = 24, HC = 24