Anti-human CD47 monoclonal antibodies, B6H12 and SRF231 induce phagocytosis of TCL cells over nonmalignant T cells in vitro. (A) B6H12 induced phagocytosis of peripheral blood CD3⁺ T cells from 4 healthy donors using mBMDM and hMDM in comparison with isotype control (mIgG1κ) are presented. The human anti-CD20 mAb rituximab (Rit) and anti-CD52 mAb alemtuzumab (Alem) both with hIgG1 isotype were used as negative and positive controls, respectively. (B, C) B6H12-mIgG1κ and SRF231 mediated phagocytosis of HuT-78, Myla, and HH (cutaneous T-cell lymphoma) and SUP-M2, MAC2A, Karpas 299 (K-299) (peripheral T-cell lymphoma) cells compared with isotype controls (mIgG1κ and hIgG4). Fold change in CFSE⁺ of CD11b⁺ mBMDMs and of CD14⁺ hMDMs relative to the isotype control (mIgG1κ for B6H12-mIgG1κ, hIgG4 for SRF231, and hIgG1 for B6H12-hIgG1) for that cell line. Alemtuzumab was used as a positive control for induction of ADCP for CD52-expressing HuT-78 cell line and as a negative control for other lines. B6H12-mIgG1κ and B6H12-hIgG1 mediated phagocytosis of Myla and MAC2A relative to isotype controls is plotted for direct comparison between antibody isotypes. (D) Flow plots of mBMDM-engulfed CFSE⁺ tumor cells with SRF231 and hIgG4 isotype control upon incubation of tumor cells ex vivo harvested from PDXs (ALK+ ALCL [WCTL-81162], T-PLL [DFTL-28776], AITL [DFTL-47880], and PTCL-NOS [DFTL-84867]).