Nonopsonic PE phagocytosis is inhibited with anti-CD36 antibodies.

(A) Fc receptor–blocked monocytes were pretreated with 10-μg/mL monoclonal anti-CD36 (OKM5, FA6-152), anti-CD49d (HP2.1), or anti–PECAM-1 (HEC7) antibodies for 20 minutes at room temperature and then washed. Phagocytosis assays with synchronized PE cultures were performed as before. (B) Fc receptor–blocked monocytes were pretreated with 10-μg/mL monoclonal anti-TSP (C6.7), anti-α_vβ₃ (23C6), or anti-CD36 antibodies for 30 minutes and washed. Phagocytosis assays were performed as before. (C) Synchronized PEs were suspended in a 0.05% trypsin-EDTA solution and incubated at 37°C for 30 minutes. PEs were then washed twice, and phagocytosis assays were performed as before. Alternatively, Fc receptor–blocked monocytes were pretreated with 10-μg/mL monoclonal anti-CD36, and phagocytosis assays were performed as before. (D) Fc receptor–blocked monocytes were pretreated with 10-μg/mL monoclonal anti–ICAM-1 or anti-CD36 antibody for 30 minutes and washed. Phagocytosis assays were performed as before. In all cases, cumulative data from at least 3 independent experiments are presented as mean ± SEM; n ≥ 3 per group. **, P < .01; ***,P < .001 vs PEs (ANOVA with post hoc Tukey).