Phagocytosis mediated by three distinct Fc gamma receptor classes on human leukocytes.
We have evaluated the capacity of the three major classes of human Fc gamma R to mediate phagocytosis by measuring the ability of adherent phagocytes to internalize erythrocytes coated with anti-Fc gamma R mAb. Five different cell types were studied, freshly purified monocytes, cultured monocytes, alveolar macrophages, freshly purified polymorphonuclear neutrophilic leukocytes, and PMNs cultured in IFN-gamma. Fc gamma RI and Fc gamma RII on whichever cells they were expressed were capable of phagocytosing anti-Fc gamma R mAb-coated erythrocytes. Furthermore, Fc gamma RIII on mononuclear phagocytes, which appears to be a conventional integral membrane protein that spans the lipid bilayer, was capable of phagocytosing anti-Fc gamma RIII-coated erythrocytes. However, Fc gamma RIII on neutrophils, a molecule linked to the membrane by a phosphatidylinositol-glycan moiety, although binding anti-Fc gamma RIII-coated erythrocytes vigorously was incapable of mounting a phagocytic response. This deficiency correlates with the limited capacity of Fc gamma RIII on neutrophils to mediate superoxide generation and antibody-dependent cell-mediated cytotoxicity and it may be related to the unique structural features of Fc gamma RIII.
Anderson
C L
CL
Department of Internal Medicine, Ohio State University College of Medicine, Columbus 43210.
Shen
L
L
Eicher
D M
DM
Wewers
M D
MD
Gill
J K
JK
D000906:Antibodies; D015703:Antigens, CD / Q000276:immunology; D000943:Antigens, Differentiation / Q000276:immunology / Q000502:physiology*; D002448:Cell Adhesion; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000502:physiology; D007962:Leukocytes / Q000276:immunology* / Q000502:physiology; D008264:Macrophages / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis; D011961:Receptors, Fc / Q000276:immunology / Q000502:physiology*; D017452:Receptors, IgG
D000906:Antibodies; D015703:Antigens, CD; D000943:Antigens, Differentiation; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG