Fig. 3

SIRPα-αCD123 fusion antibodies block CD47 and stimulate phagocytosis of MOLM-13. A CD47 blockade on MOLM-13 cells with 100 nM antibodies determined by FITC αCD47 binding using flow cytometry. Background fluorescence was subtracted from the FITC αCD47 signal and normalized to isotype to calculate the CD47 blockade. Mean ± SEM of n = 4 independent experiments. B ADCP of MOLM-13 cells at a 50 pM concentration of antibodies after 3 h at an E:T ratio of 1:1. ADCP was measured as the percentage of double-positive cells from macrophages and normalized to the isotype control. Bar charts represent the mean ± SEM from n = 7 different donors. Statistical differences were determined by one-way ANOVA using Holm-Sidak's post hoc test. *p < 0.05, ***p < 0.001, ****p < 0.0001, not significant (ns)