B-cell lymphoma cells display a specific resistance toward anti-CD20–mediated neutrophil killing. (A) Neutrophil ADCC of wild type and Raji CD47KO cells opsonized with rituximab (rtx), obinutuzumab (obi), ofatumumab (ofa), or anti-HLA-DR (DR) (n = 6-8 donors from 3-4 independent experiments); all anti-CD20 opsonized conditions were not significant (ns) compared with the control condition. (B) Epitopes and characteristics of rituximab, obinutuzumab, and ofatumumab. Rituximab and obinutuzumab have overlapping but distinct epitopes; ofatumumab binds to the 2 outer loops of CD20. (C) Neutrophil trogocytosis of wild type and Raji CD47KO cells opsonized with rituximab, obinutuzumab, ofatumumab, or anti-HLA-DR (n = 4-11 donors from 2-5 independent experiments); statistics indicate the comparison between opsonized and control conditions of the wild type or CD47KO cells. (D) NK cell ADCC of wild-type Raji cells (NK cells do not express SIRPα) opsonized with rituximab (n = 14 donors from 7 independent experiments). (E) Macrophage ADCC of wild type Raji cells opsonized with rituximab (n = 3 donors from 2 independent experiments). Data analysis used paired Student t test. Data are mean ± standard error of the mean (SEM). *P ≤ .05; **P ≤ .01; ****P ≤ .0001. MFI, mean fluorescent intensity.