FIGURE 1.

IgG-opsonized latex beads induce FcγR-mediated phagocytosis via ADPR-cyclase activation in J774A.1 murine macrophages. ADPR-cyclase activity was assessed in J774A.1 murine macrophages through an NGD⁺ assay where 200 μm NGD⁺ was used as a substrate as described in “Experimental Procedures.” A, a decrease in ADPR-cyclase activity at the membrane surface was observed in a time-dependent manner after initiating FcγR-mediated phagocytosis with IgG-opsonized latex beads. The data represent the mean ± S.D. cGDPR formation of three experiments. p < 0.05 (*) versus zero time. p < 0.01 (**) versus zero time. Closed squares and closed circles are latex bead and IgG-opsonized latex bead groups, respectively. B, unaffected J774A.1 macrophages (upper left panel) were preincubated with 3.0 μm latex beads without IgG opsonization (LB) (upper right panel) or with IgG opsonization (IgG-LB) (lower left panel) for 30 min at 37 °C in 5% CO₂ (magnification ×40). Lower right panel, statistic analysis of phagocytosis in J774A.1 cells. p < 0.001 (#) versus no-ingested latex bead group of J774.A1 cells.