siRNA mediated knock-down of the 72-5ptase enhances FcγR-mediated but not CR3-mediated phagocytosis in RAW264.7 macrophages and primary BMM. RAW264.7 macrophages or primary bone marrow macrophages (BMM) differentiated for 6 days were transiently transfected with siCON or si72-5ptase oligonucleotides. (A) After 72 hours cells were lysed and immunoblotted with 72-5ptase-specific antibodies or β-tubulin-specific antibodies, the latter to detect protein loading. The relative 72-5ptase protein expression in RAW264.7 macrophages and primary BMM was determined by densitometry and normalized to β-tubulin loading control and expressed as percentage of siCON, which was designated 100%. Data represent the mean (± SEM) of 3 (RAW264.7) or 2 (primary BMM) independent experiments. Cells transfected with siCON or si72-5ptase were stimulated with (B) eIgG or (C) SOZ for 10 minutes. Phagocytic index represents the number of particles phagocytosed per 100 cells and normalized to vector, which was designated 100%. Data are expressed as the mean (± SEM) of 3 independent experiments. *P ≤ .05.