Phagocytosis assay
Latex beads (L3030, Sigma, St. Louis, USA) were used to detect the potential influence of LILRA3 on the phagocytosis capacity of U937 cells. U937 cell lines harboring pWSLV-02-LILRA3 or pWSLV-02 were seeded in 6-well plates (1.0×105cells/well) in RPMI-1640 medium containing 1% FBS, followed by incubation at 37°C in humidified 5% CO2 for 20 hours. A mixture of FBS and latex beads (FBS: latex beads = 20:1) was added to each well. The percentage of GFP+ Texas Red+ cells was then analyzed by FCM at 0.5, 6, 12 and 24 hours.