Mouse CD47 expression attenuates phagocytosis of porcine cells in vitro by mouse macrophages. (A) CFSE-labeled LCL-mCD47 or LCL-neo cells (2.5 × 104/well) were incubated with mouse intraperitoneal macrophages (5 × 105/well) in 96-well plate at 37°C or 4°C (controls); cultures were harvested 3 hours later and phagocytosis was determined by flow cytometry. (Left panel) Percent engulfment in Mac-1+ cells (mean ± SDs of 4 experiments); (right panel) representative staining profiles showing engulfment (at 37°C, top) or background (4°C, bottom). (B) LCL-mCD47 and LCL-neo cells labeled with different colors (CFSE or PKH-26) were mixed at a 1:1 ratio (2.5 × 104 each) and cultured with 5 × 105 CMAC-labeled mouse intraperitoneal macrophages (blue) for 3 hours; then nonengulfed target cells were washed off and phagocytosis was assessed by fluorescence microscopy. Pictures shown are images taken from an experiment, in which LCL-mCD47 and LCL-neo cells were labeled with CFSE (green) and PKH-26 (red), respectively. Data are representative of 3 experiments.
