Impaired responses of AMs or DCs to IgG-IC stimulation. (A-B) AMs were stimulated with (A) IgG-ICs preformed with a fixed concentration of rabbit IgG anti-OVA and 0.1 (IC-0.1), 1 (IC-1), or 10 (IC-10) μg/mL OVA or with (B) insoluble IgG-ICs (IIC), preformed using rabbit IgG anti-BSA and BSA, at different concentrations. (C-D) DCs were stimulated with (C) IgG-ICs prepared as in panel A or with (D) different concentrations of PMA. (A-D) Shown are mean concentrations of TNF-α released ± SEM of at least 3 independent experiments. (E) CD86 expression after incubation of DCs with IgG-ICs. Broken lines indicate control DCs; and bold lines, GPI-anchor-deficient DCs; shown are fluorescence intensity plots representative of 3 experiments. (F) IgG-IC induced presentation of OVA epitopes to OVA-specific T cells. DCs were incubated with medium (med), IgG-ICs prepared as for panel A, or 10 μg/mL OVA alone (ova-10) as control, and proliferation of OVA-specific T cells was assessed by measuring [³H]-thymidine uptake; shown are mean triplicate values ± SEM of a representative experiment. (A-D,F) ▪ indicates control cells (WT); ▦, GPI-anchor-deficient cells (KO). ^*Significant differences (P < .05) with values for WT cells.