CD44 MEDIATES EFFECTS OF HYALURONAN ON PHAGOCYTOSIS OF MACROPHAGES / 解剖学报

ABSTRACT

Objective To investigate the effects of hyaluronan(HA) on phagocytosis of macrophages and to explore the mechanism.Methods CD44 of macrophages was labeled with immunochemical method.In phagokinetic track assay,the areas without gold particles around the cells were measured with an image analyzer,shape of the cells was viewed under a scanning electron microscope.In fluorescent bead phagocytosis assay,the phagocytosed beads were conunted,the distribution of intracellular F-actin was viewed.In HA-coated bead phagocytosis assay,the phagocytosed beads were counted,shape of the cells was viewed with scanning electron microscope,the level of the intracellular Ca~(2+) was analyzed with confocal laser scanning microscope when the beads were phagocytosed.After treatment with anti-CD44 antibody,the changes of phagocytosis of the cells were examined.Results CD44 expressed on macrophages.The phagocytosing cells were round,their lamellipodia and filopodia were short.The membrane of the cells formed cup-like invagination when they engulfed particles and beads.In HA group,the phagocytosed gold particles and fluorescent beads increased.There was rich F-actin in the area where the fluorescent bead was engulfed.In HA-coated group,number of the phagocytosed HA-coated beads was great,the level of the intracellular Ca~(2+) in the area where the bead was engulfed increased significantly.After treatment with anti-CD44 antibody,the phagocytosed gold particles,fluorescent beads and HA-coated beads decreased.Conclusion HA promotes phagocytosis of macrophages,CD44 mediates effects of HA on phagocytosis of the cells.