(A and B) Macrophages were cultured in chamber slides pre-coated with 4 µg/ml C1q (black bars) or the control protein human serum albumin (HSA) (white bars) for 30 minutes and then fed sheep erythrocytes suboptimally opsonized with IgG (EAIgG) for an additional 30 minutes (A, n=4) or apoptotic Jurkat cell sat a 1:3 macrophage to apoptotic cell ratio for 1 hour (B, n=3). Bars represent the average ± SEM. ***p< 0.001, Student’s t test.(C and D) Phagocytosis assays were performed as in A and B except macrophages were adhered to protein coated wells for five hours instead of 30 minutes prior to feeding EAIgG (C) or apoptotic cells (D). Bars represent the average ± SEM from three to six experiments. *p < 0.05; ***p< 0.001, Student’s t test. (E and F) BMDM were cultured as in C and D in the presence and absence of 100 µM cycloheximide. Bars represent the average ± SEM from three independent experiments. **p< 0.01; ***p< 0.001, two-way ANOVA, Bonferroni multiple comparison tests.