Different membrane anchors of Fc gamma RIII (CD16) on K/NK-lymphocytes and neutrophils. Protein- vs lipid-anchor.
Fc gamma RIII (CD16), the type three receptor for the Fc portion of IgG, is expressed on neutrophils, killer (K)/NK lymphocytes and macrophages. K/NK lymphocyte Fc gamma RIII, which plays a role in antibody-dependent cellular cytotoxicity, is an efficient signal transducing molecule, whereas neutrophil Fc gamma RIII, which plays a role in immune-complex clearance, seems less efficient in signal transduction. Neutrophil Fc gamma RIII has been reported to be a glycan-phosphatidylinositol-anchored membrane protein. Our studies suggest that K/NK lymphocyte Fc gamma RIII is protein-anchored rather than glycan-phosphatidylinositol-anchored. That is, K/NK lymphocyte Fc gamma RIII was resistant to phosphatidylinositol-specific phospholipase C and surface expression of Fc gamma RIII was not affected on K/NK lymphocytes from patients with paroxysmal nocturnal hemoglobinuria, a disorder of hemopoietic stem cells resulting in deficient expression of glycan-phosphatidylinositol-anchored proteins. Different membrane anchoring mechanisms of the Fc gamma RIII may account for different consequences of the ligand binding to two cell types.
Ueda
E
E
Department of Clinical Research, Osaka University, Japan.
Kinoshita
T
T
Nojima
J
J
Inoue
K
K
Kitani
T
T
D000943:Antigens, Differentiation / Q000378:metabolism* / Q000502:physiology; D006457:Hemoglobinuria, Paroxysmal / Q000097:blood; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism* / Q000502:physiology; D008565:Membrane Proteins / Q000378:metabolism* / Q000502:physiology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology; D011961:Receptors, Fc / Q000378:metabolism* / Q000502:physiology; D017452:Receptors, IgG; D015398:Signal Transduction / Q000187:drug effects
D000943:Antigens, Differentiation; D007074:Immunoglobulin G; D008563:Membrane Lipids; D008565:Membrane Proteins; D011961:Receptors, Fc; D017452:Receptors, IgG; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase