Fig. 1: Characterization of CD276 expression in AML cell lines and patient-derived leukemia cells.

A CD276 mRNA expression in AML bone marrow (BM) (n = 350) and AML peripheral blood (PB) (n = 318) and healthy BM (n = 16) samples were analyzed using the public data sets of the BeatAML program [29]. B Flow cytometric analysis of surface CD276 expression on the indicated AML cell lines using chimeric mouse anti-human 8H8 mAb against CD276 and corresponding isotype control. Example histograms of one representative experiment out of three with similar results are shown. C The gating strategy for two representative patient-derived AML samples is outlined as follows: singlets, viable (7-AAD^-), leukemic blast marker (CD33⁺), and the percentage of CD276 expression. D CD276 expression on AML patient blasts (n = 68) is shown as percentage of CD276⁺ AML blasts and E as SFI levels. Expression levels above SFI of 1.5 and 10% for positive cells were considered as positive expression (indicated by the dotted line and shown by the corresponding pie chart). F Schematic representation of the generated CD276 antibody with a modified Fc part optimized for increased affinity to CD16 (8H8_SDIE) and the corresponding control mAb (MOPC_SDIE). G Titration of the 8H8_SDIE mAb indicated AML cell lines and H on AML patient sample analyzed by flow cytometry. MOPC_SDIE was used as an isotype control. The example data show the MFI values of one representative experiment out of a total of three with comparable results.