title: Fcgamma receptors exhibit different phagocytosis potential in human neutrophils.
abstract: In neutrophils, two receptors for IgG antibodies, namely FcgammaRIIA and FcgammaRIIIB are constitutively expressed, and a third one, FcgammaRI, can be upregulated by interferon-gamma. Whether FcgammaRIIIB is capable of triggering phagocytosis by itself is still controversial. The main role of FcgammaRI has not been clearly established in these cells. To address this problem, neutrophils were treated with interferon-gamma, and then phagocytosis mediated by each type of Fcgamma receptor was evaluated by flow cytometry. FcgammaRIIA was the most efficient receptor for phagocytosis. FcgammaRIIIB could mediate phagocytosis but much less efficiently than FcgammaRIIA. Both FcgammaRIIA- and FcgammaRIIIB-mediated phagocytosis were blocked by inhibitors of Src family kinases, Syk, PI 3-K, and ERK. In contrast, interferon-gamma-induced FcgammaRI was not able to mediate phagocytosis. Also, FcgammaRI did not activate ERK in the nucleus, but was however able to stimulate an efficient calcium rise. These data show that different neutrophil Fcgamma receptors possess different phagocytosis capabilities: FcgammaRIIA and FcgammaRIIIB, but not FcgammaRI, promote phagocytosis.
authors.affiliation: Programa de Doctorado en Ciencias Biomédicas, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Selma
authors.initials: S
authors.lastname: Rivas-Fuentes
authors.forename: Erick
authors.initials: E
authors.lastname: García-García
authors.forename: Georgina
authors.initials: G
authors.lastname: Nieto-Castañeda
authors.forename: Carlos
authors.initials: C
authors.lastname: Rosales
mesh_terms: D000906:Antibodies; D020013:Calcium Signaling / Q000276:immunology; D002469:Cell Separation; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D010587:Phagocytosis / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D000906:Antibodies; D017452:Receptors, IgG; D007371:Interferon-gamma; D019061:src-Family Kinases