FcγRIIIA is functional on PMNs. PMNs were purified from FcγRIIIB WT donors and the null individual, and their functional activity was measured. (A) Activation was measured by CD11b induction after stimulation with 10 µg/mL anti-CD16 F(ab′)2, whole antibody (MAb), or anti-CD32 F(ab′)2 antibodies. (B) Phagocytosis was measured by coincubation of PMNs for 1 hour with RTX-coated beads in the absence (CTRL) or presence of 10 µg/mL anti-CD16 F(ab′)2 or anti-CD32 F(ab′)2 antibodies. The percentage of PMNs having phagocytosed ≥1 bead was measured. (C) Trogocytosis was measured by coincubation of purified PMNs with PKH67-labeled CLL B cells in the presence of 1 µg/mL RTX and presence or absence of 10 µg/mL blocking anti-CD32 and anti-CD16 IgG antibodies. The percentage of PKH67+ PMNs was then measured after 4 hours by flow cytometry. The results are the means and standard deviations of 5 to 8 independent experiments. *P < .05, **P < .01, ***P < .001 vs the respective controls without antibody (CTRL).