Stabilin-1 and stabilin-2 in HSECs significantly enhance PS-bead engulfment by macrophages. (A-B) Blockade of stabilin-1 and stabilin-2 abolishes the HSEC-mediated enhancement of PS-bead engulfment in coculture. P388D1 cells were seeded on the BMQC-labeled HSEC monolayer, and the next day, NBD-PC–labeled PS beads were added to the coculture of P388D1 and HSEC cells in the presence or absence of anti-stabilin-1 and/or anti-stabilin-2 Abs. After incubation for 1 hour, engulfment of PS beads by P388D1 cells (Q4 regions) was quantified by FACS analysis. A representative result is shown in panel A. Data represent mean ± SD from at least 3 experiments in panel B; t test: *P < .01 versus P388D1 only; #P < .01 versus untreated control. (C) Phagocytosis assays were performed in a coculture of P388D1 and stabilin-1 or stabilin-2 shRNA-treated HSECs. Data represent mean ± SD from at least 3 experiments; t test: *P < .01 versus P388D1 only; #P < .01 versus untreated control.