Binding of monomeric immunoglobulins to fc receptors of mouse macrophages.
J C Unkeless,H N Eisen +1 more
TLDR
From the rapidity of association and dissociation, it appears that the surface of the macrophage is in a dynamic equilibrium with IgG2a molecules in the cell's immediate microenvironment.Abstract:
The binding properties of surface receptors of immunoglobulins on mouse macrophages were studied with mouse myeloma proteins and normal peritoneal macrophages, thioglycollate-stimulated macrophages, and a macrophage cell line, P388D1. Primary cultures of mouse embryo fibroblasts served as controls. IgG2a proteins were bound strongly;IgG2b was bound weakly (one-twentieth as well as IgG2a);IgM, IgA, and IgG1 were not bound significantly. The number of binding sites per cell for IgG2a was 4 X 10(5) for thioglycollate-stimulated cells and 1 X 10(5) for normal and P388D1 cells. Binding was exothermal: with decreasing temperature the equilibrium (association) constants increased and dissociation rate constants decreased (at 37degreesC the respective values were 2 X 10(7) M-1 and 0.26 min-1, the latter value corresponds to a half time for dissociation of 2.6 min). From the rapidity of association and dissociation, it appears that the surface of the macrophage is in a dynamic equilibrium with IgG2a molecules in the cell's immediate microenvironment. The receptors for IgG2a are clearly specific for determinants in the immunoglobulin constant domain: two IgG2a proteins with greatly different isoelectric points (determined by isoelectric focusing) were bound with the same affinity to the same receptors; moreover, the Fc fragment was bound and Fab fragments were not. The Fc receptors for IgG2a proteins were readily eliminated by exposing macrophages briefly to trypsin. The receptors were regenerated during subsequent cultivation in serum-free medium; regeneration was inhibited totally by cycloheximide and partially by actinomycin D.read more
Citations
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Journal ArticleDOI
Fc RECEPTOR BIOLOGY
TL;DR: In this paper, a review of membrane Fc receptors (FcR) of the immunoglobulin superfamily is presented, focusing on the mechanisms by which FcR trigger and regulate biological responses of cells on which they are expressed.
Journal ArticleDOI
Characterization of a monoclonal antibody directed against mouse macrophage and lymphocyte Fc receptors.
TL;DR: The ability of the hybridoma IgG to inhibit mouse FcRII was independent of the major histocompatibility complex and the monoclonal 2.4G2 IgG antigenic determinant was not present on rat, guinea pig, rabbit, or human F cR-bearing cells.
Journal ArticleDOI
Identification of the membrane glycoprotein that is the C3b receptor of the human erythrocyte, polymorphonuclear leukocyte, B lymphocyte, and monocyte.
TL;DR: Direct evidence for the identity of gp205 as the C3b receptor of the four cell types was obtained when detergent-solubilized membrane proteins of the surface-radioiodinated cells were reacted with anti- gp205 and the immunoprecipitate was analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate.
Book ChapterDOI
Molecular basis of Fc receptor function.
Mark D. Hulett,P. Mark Hogarth +1 more
TL;DR: The structural analysis of the functional basis of FcγR and FCɛR signaling is beginning to shed some light on the way these receptors trigger biological responses, and the molecular dissection of the pathways involved in signaling is also underway.
Journal ArticleDOI
Structure and function of human and murine receptors for IgG.
TL;DR: TheFCyRs provide a crucial link between the phagocytic effector cells and the lymphocytes that secrete Ig, since the macro phage/monocyte, polymorphonuclear leukocyte, and NK cell FCyRs confer an element of specific recognition mediated by IgG.
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Properties of antibodies cytophilic for macrophages
Arthur Berken,Baruj Benacerraf +1 more
TL;DR: Cytophilic activity is not complement dependent, and was shown to be that property of opsonizing antibody which provides the receptors that permit the binding of the antibody to the macrophage cell membrane in preparation for phagocytosis.