Effect of Inositol-phosphatase on Fc Receptor-mediated Phagocytosis of Macrophages.
- Author:
Jong Hyun KIM
1
Author Information
- Publication Type:Original Article
- Keywords: Fc receptor; macrophage; SH2 domain-containing inositol-phosphatase (SHIP); phagocytosis
- MeSH: Cytophagocytosis; Cytoplasm; DNA, Complementary; Erythrocytes; Macrophages*; Phagocytosis*; Phosphatidylinositol 3-Kinases; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Receptors, Fc; Sheep; Ships; Tyrosine; Vaccinia
- From:Immune Network 2005;5(3):144-149
- CountryRepublic of Korea
- Language:Korean
- Abstract: BACKGROUND: Fc receptor-mediated phagocytosis is a complex process involving the activation of kinases and phosphatases. FcgammaRIIB has been known to transduces inhibitory signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) in cytoplasmic domains. In this study, we examined the involvement of inositol-phosphatase in the Fc receptor-mediated phagocytosis. METHODS: J774 cells were infected using vaccinia viral vector containing SH2 domain-containing inositol-phosphatase (SHIP) cDNA and stimulated with the sensitized sheep red blood cells. RESULTS: Stimulation of J774 cells induced the tyrosine phosphorylation of SHIP which was maximal at 5 minutes. Phosphatidylinositol-3 (PI-3) kinase inhibitor (wortmannin) inhibits J774 cell phagocytosis of sensitized sheep red blood cells in a dose-dependent manner. Heterologious expression of SHIP in J774 cells inhibits phagocytosis of sensitized sheep red blood cells in a dose-dependency manner, but catalytically dead mutants of SHIP has no effect on phagocytosis. CONCLUSION: These results strongly suggest that the active signals mediated by PI-3 kinase are opposed by inhibitory signals through SHIP in the regulation of Fc receptor-mediated phagocytosis.
