Combination of Dara and Hu5F9-IgG2σ increases in vitro phagocytosis in T-ALL cell lines. (A) CD47 and CD38 surface expression in P12, MOLT-13, and HSB-2 examined by using flow cytometry. (B) Antibody-dependent cellular phagocytosis analyzed in P12, MOLT-13, and HSB-2 treated with Dara, a CD47-blocking antibody (Hu5F9-IgG2σ), the combination (Dara + Hu5F9-IgG2σ [combi]), or no treatment (control) using live cell imaging. Graph illustrates 5 independent experiments with different human macrophages (n = 5, standard error of the mean). (C) Representative pictures of phagocytosed P12 cells (engulfed cells in red) subjected to Dara, Hu5F9-IgG2σ, the combination (Dara + Hu5F9-IgG2σ [combi]), or no treatment (control). (D-E) ADCP in CD47-depleted P12 (D) and MOLT-13 (E) cells subjected to Dara, Hu5F9-IgG2σ, the combination (Dara + Hu5F9-IgG2σ [combi]) of both antibodies, or untreated (control). Graph depicts 4 independent experiments with different human macrophages (n = 4, standard error of the mean). Statistical analysis: nonparametric Mann-Whitney U test (two-tailed). *P < .05, **P < .01. MFI, mean fluorescence intensity; ns, not significant; ROI, red object counts per image.