FcαRI monovalent targeting induces apoptosis more strongly than multimeric targeting. (A) FcαRIR209L/γ RBL transfectants were incubated with 10 μg/mL anti-FcαRI (A77) Fab or preformed complexes of anti-FcαRI (A77) F(ab′)2 and F(ab′)2 rabbit anti–mouse IgG. After 24 hours cells were analyzed for annexin V/PI double-positivity as described in “Materials and methods.” Values indicate the percentage of double-positive cells and are means ± SD of at least 3 separate experiments performed in duplicate. *P < .01. (B) FcαRIR209L/γ RBL transfectants were incubated with 50 μg/mL IgA or preformed complexes of 50 μg/mL IgA and 100 μg/mL goat anti–human IgA. After 10 hours cells were analyzed for annexin V/PI double-positive population as described in “Materials and methods.” Values indicate the percentage of double-positive cells and are means ± SD of at least 3 separate experiments performed in duplicate. *P < .01.
