scholarly journals MACROPHAGE-MELANOMA CELL HETEROKARYONS

1971 ◽  
Vol 134 (4) ◽  
pp. 947-962 ◽  
Author(s):  
Saimon Gordon ◽  
Zanvil Cohn
Keyword(s):  
Melanoma Cell ◽  
Peritoneal Macrophages ◽  
Red Cells ◽  
Similar Treatment ◽  
Coated Particles ◽  
Macrophage Receptors ◽  
Ehrlich Ascites ◽  
Surface Receptor ◽  
Plasma Membrane Receptor ◽  
Mouse Peritoneal Macrophages

Mouse peritoneal macrophages possess a specific plasma membrane receptor for antibody-coated particles. Sheep red cells coated with rabbit 7S antibody attach readily to the macrophage surface and are subsequently interiorized. The fusion of macrophage with nonphagocytic mouse melanoma cells produces heterokaryons in which the macrophage receptor is drastically altered. The receptor is present shortly after fusion and heterokaryons are actively phagocytic. The ability to bind and ingest red cells is, however, progressively lost over the next 12–24 hr and does not reappear thereafter. Exposure of heterokaryons to trypsin (1–100 µg/ml for 30 min at 37°C) results in the reappearance of initial receptor activity and the unmasking of the surface receptor. This property is again lost upon subsequent cultivation. The masking process takes place when cells are cultivated in the absence of IgG so that the adsorption of antibody from the medium is not responsible for this phenomenon. Inhibition of heterokaryon protein synthesis preserves phagocytic activity in a reversible fashion and prevents the masking of macrophage receptors. Inhibition of melanoma RNA synthesis before fusion is also able to block subsequent masking, but is ineffective if delayed until after fusion. Ultraviolet irradiation of the melanoma cell before fusion prevents subsequent masking, whereas similar treatment of the macrophage has no effect. Cells differ markedly in their ability to mask the macrophage phagocytic receptor after fusion. Ehrlich ascites tumor cells mask the receptor rapidly, primary chick fibroblasts minimally, and embryonic chick erythrocytes not at all.

scholarly journals Internalization and degradation of macrophage Fc receptors during receptor-mediated phagocytosis.

1983 ◽  
Vol 96 (3) ◽  
pp. 887-895 ◽  
Author(s):  
I S Mellman ◽  
H Plutner ◽  
R M Steinman ◽  
J C Unkeless ◽  
Z A Cohn
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Rabbit Antiserum ◽  
Fc Receptors ◽  
Peritoneal Macrophages ◽  
Fc Receptor ◽  
Plasma Membrane Proteins ◽  
Coated Particles ◽  
Macrophage Receptors ◽  
Mouse Peritoneal Macrophages

Macrophage receptors for the Fc domain of immunoglobulin G (IgG) can mediate the efficient binding and phagocytosis of IgG-coated particles. After internalization, phagocytic vacuoles fuse with lysosomes, initiating the degradation of their contents. Using specific monoclonal and polyclonal antireceptor antibodies, we have now analyzed the internalization and fate of Fc receptors during the uptake of IgG-coated erythrocytes and erythrocyte ghosts by mouse peritoneal macrophages. Receptor-mediated phagocytosis led to the selective and largely irreversible removal of Fc receptors (greater than 50%) from the macrophage plasma membrane. The expression of several other plasma membrane proteins (including a receptor for complement), recognized by a series of antimacrophage monoclonal antibodies, was affected only slightly. Interiorized Fc receptors were rapidly and selectively degraded. This was demonstrated by a series of turnover studies in which Fc receptor was immunoprecipitated from lysates of 125I-labeled macrophages. These experiments were made possible by the development of a polyclonal rabbit antiserum, raised against isolated Fc receptor, which recognized the receptor even in the presence of bound ligand. In control cells, the receptor turned over with a t1/2 of approximately 10 h; after phagocytosis, greater than 50% of the receptors were degraded with a t1/2 of less than 2 h. The turnover of other unrelated plasma membrane proteins was unaffected (t1/2 of 18-23 h) under these conditions.

scholarly journals Characterization of murine peritoneal macrophage receptors for fibrin(ogen) degradation products

Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1224-1228 ◽  
Author(s):  
S Rajagopalan ◽  
SV Pizzo
Keyword(s):  
Degradation Products ◽  
Peritoneal Macrophages ◽  
Receptor System ◽  
Human Fibrinogen ◽  
Murine Peritoneal Macrophage ◽  
High Affinity ◽  
Macrophage Receptors ◽  
Low Concentrations ◽  
Mouse Peritoneal Macrophages

Abstract The binding of human fibrinogen degradation fragments D1, E, X, and Y, as well as fibrin fragment D1 dimer, to mouse peritoneal macrophages was examined. A Scatchard plot of fragment D1 binding was biphasic, suggesting two classes of receptors. Fragments D1, D1 dimer, X, and Y in low concentrations bound to macrophages with high affinity (Kd = 23 to 73 X 10(-11) mol/L). Fragment E bound specifically but at a much lower level than the other fragments. Fragment D1 was able to compete for the binding of radiolabeled fragments X and Y but not radiolabeled fragment E. These studies indicate that fragments D and E are recognized by separate receptor systems but that all of the fibrinogen degradation products that contain the D domain are recognized by the same receptor system.

scholarly journals Studies on the mechanism of phagocytosis. I. Requirements for circumferential attachment of particle-bound ligands to specific receptors on the macrophage plasma membrane.

1975 ◽  
Vol 142 (5) ◽  
pp. 1263-1282 ◽  
Author(s):  
F M Griffin ◽  
J A Griffin ◽  
J E Leider ◽  
S C Silverstein
Keyword(s):  
Plasma Membrane ◽  
Sheep Erythrocyte ◽  
Peritoneal Macrophages ◽  
Membrane Receptors ◽  
Macrophage Receptors ◽  
Specific Receptors ◽  
Particle Ingestion ◽  
Plasma Membrane Receptors ◽  
Mouse Peritoneal Macrophages

These experiments were designed to evaluate the role of macrophage plasma membrane receptors for the third component of complement (C) and for the Fc portion of IgG in the ingestion phase of phagocytosis. Sheep erythrocyte (E) were coated with anti-E IgG [E(IgG)]; these E(IgG) were then attached to cultivated monolayers of mouse peritoneal macrophages under conditions which reversibly inhibit ingestion of E(IgG). The E(IgG)-macrophage complexes were further incubated under similar conditions with an antimacrophage IgG fraction which blocks Fc receptor-mediated ingestion but has no effect upon ingestion mediated by other phagocytic receptors. When these cultures were subsequently incubated under conditions optimal for particle ingestion, phagocytosis of the IgG-coated erythrocytes did not occur; the erythrocytes remained bound to the Fc receptors of the macrophage plasma membrane. To determine whether ligands must cover the entire surface of an attached particle to permit ingestion of that particle, C-coated E [E(IgM)C] were bound to the C receptors of thioglycollate-induced (activated) macrophages at 4 degrees C. E(IgM)C-macrophage complexes were then trypsinized at 4 degrees C, a procedure which resulted in cleavage of erythrocyte-bound C3b molecules to a form of C3 not recognized by the macrophage receptors for C3b. Under the conditions used, trypsin did not affect the attachment of E(IgM)C to the macrophage surface or the macrophage receptors for C3b. When these trypsin treated E(IgM)C-macrophage complexes were incubated at 37 degrees C, the bound E(IgM)C were not ingested; the erythrocytes remained attached to the macrophage plasma membrane via the macrophage's C receptors. These results indicate that attachment of a particle to specific receptors on the macrophage plasma membrane is not sufficient to trigger ingestion of that particle. Rather, ingestion requires the sequential, circumferential interaction of particle-bound ligands with specific plasma membrane receptors not involved in the initial attachment process.

scholarly journals Characterization of murine peritoneal macrophage receptors for fibrin(ogen) degradation products

Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1224-1228 ◽  
Author(s):  
S Rajagopalan ◽  
SV Pizzo
Keyword(s):  
Degradation Products ◽  
Peritoneal Macrophages ◽  
Receptor System ◽  
Human Fibrinogen ◽  
Murine Peritoneal Macrophage ◽  
High Affinity ◽  
Macrophage Receptors ◽  
Low Concentrations ◽  
Mouse Peritoneal Macrophages

The binding of human fibrinogen degradation fragments D1, E, X, and Y, as well as fibrin fragment D1 dimer, to mouse peritoneal macrophages was examined. A Scatchard plot of fragment D1 binding was biphasic, suggesting two classes of receptors. Fragments D1, D1 dimer, X, and Y in low concentrations bound to macrophages with high affinity (Kd = 23 to 73 X 10(-11) mol/L). Fragment E bound specifically but at a much lower level than the other fragments. Fragment D1 was able to compete for the binding of radiolabeled fragments X and Y but not radiolabeled fragment E. These studies indicate that fragments D and E are recognized by separate receptor systems but that all of the fibrinogen degradation products that contain the D domain are recognized by the same receptor system.

scholarly journals Function and regulation of a murine macrophage-specific IgG Fc receptor, Fc gamma R-alpha.

1988 ◽  
Vol 167 (6) ◽  
pp. 1909-1925 ◽  
Author(s):  
R L Weinshank ◽  
A D Luster ◽  
J V Ravetch
Keyword(s):  
Ligand Binding ◽  
Cell Lines ◽  
Time Course ◽  
Peritoneal Macrophages ◽  
Raw 264.7 ◽  
Mrna Accumulation ◽  
Ifn Gamma ◽  
Coated Particles ◽  
Specific Igg ◽  
Mouse Peritoneal Macrophages

Ligand binding specificities of two cloned murine Fc gamma Rs (Fc gamma R-alpha, Fc gamma R-beta [9]) were determined by gene transfer into Fc gamma R negative cell lines. Both receptors were expressed as full-length molecules capable of IgG immune complex binding that was inhibitable by the mAb 2.4G2. The ligand binding profiles of these receptors were indistinguishable whereby both bound immune-complexed mouse IgG1, IgG2a, and IgG2b, but not IgG3. Neither receptor could bind monomeric IgG2a, indicating these receptors to be low-affinity IgG Fc receptors. Accumulation of the Fc gamma R-alpha mRNA can be induced with murine IFN-gamma at a concentration of 200 U/ml in the macrophage-like cell lines RAW 264.7 and J774a. The time course for induction indicates that the mRNA accumulation is transient but does not return to the uninduced level even after 50 h of treatment. Fc gamma R-beta mRNA was not induced by IFN-gamma, rather its expression was down modulated in mouse peritoneal macrophages. Both RAW and J774a cells lines exhibited increased receptor levels after IFN-gamma stimulation as measured by 125I-2.4G2 and ligand binding. In the absence of IFN-gamma, the RAW and J774a cell lines were minimally phagocytic, while P388D1 cells were actively phagocytic. In the presence of IFN-gamma, however, RAW 264.7 and J774a cells were induced to become actively phagocytic. Induction of Fc gamma R-alpha mRNA and protein by IFN-gamma may be part of the process by which macrophages become activated to engulf antibody-coated particles.

Phagocytosis by macrophages. II. The dissociation of the attachment and ingestion steps

1981 ◽  
Vol 51 (1) ◽  
pp. 189-201
Author(s):  
T. Ito ◽  
M.J. Ueda ◽  
T.S. Okada ◽  
S. Ohnishi
Keyword(s):  
Cell Surface ◽  
Divalent Cations ◽  
Peritoneal Macrophages ◽  
Metabolic Inhibitors ◽  
Assay Method ◽  
Coated Particles ◽  
Spin Resonance ◽  
Mouse Peritoneal Macrophages ◽  
Phagocytic Reaction ◽  
Number Of Particles

The phagocytic process of mouse peritoneal macrophages was dissociated, using bovine serum albumin (BSA)-coated particles containing spin-labelled cholestanone, into 2 steps: attachment of particles to the cell surface and ingestion of the particles into the cytoplasm. The number of particles was estimated from electron spin resonance (e.s.r.) measurements. The particles ingested into the cytoplasm were distinguished from those attached to the cell surface by treatment with a membrane-impermeable reducing agent, ascorbate. The validity of the assay method was tested under various conditions. The measurements provided accurate and reproducible data. The phagocytic reaction was followed as a function of time and the rate constants for the attachment and ingestion steps were obtained from the initial phase. Both steps were highly dependent on temperature. Divalent cations in the incubation medium were essential for the attachment step but apparently had no effect on the ingestion step. The metabolic inhibitors, KCN and 2-deoxyglucose, inhibited both steps. Cytochalasin B inhibited both steps, while colchicine inhibited only the attachment step but apparently had no effect on the ingestion step.

scholarly journals RECEPTORS FOR COMPLEMENT ON LEUKOCYTES

1968 ◽  
Vol 128 (5) ◽  
pp. 991-1009 ◽  
Author(s):  
Waltraut H. Lay ◽  
Victor Nussenzweig
Keyword(s):  
Divalent Cations ◽  
Peritoneal Macrophages ◽  
Red Cells ◽  
Enzyme Treatment ◽  
Rabbit Serum ◽  
Mouse Serum ◽  
Polymorphonuclear Cells ◽  
Mouse Macrophages ◽  
Antibody Complex ◽  
Mouse Peritoneal Macrophages

Sheep red blood cells sensitized by 7S, but not by 19S rabbit anti-Forssman antibodies, adhere and form rosettes on mouse macrophages and on a few monocytes and polymorphonuclear cells (PMN). When, however, C' factors from mouse serum are added to the antigen-19S antibody complex (EAC'), rosettes are formed on most mouse peritoneal macrophages and PMN and on a few monocytes. In addition EAC' also adheres to 10–25% of lymph node lymphocytes but not to thymus lymphocytes. EAC' prepared with 7S anti-Forssman antibodies has identical properties. The adherence of red cells induces an increase in the membrane activity of the leukocytes and causes injury to the red cells which rapidly become deformed and fragmented. Adherence of EAC' occurs at 37°C and is minimal at 4°C. Probably only the first four C' components are involved in this phenomenon as mouse serum deficient in C'5 or rabbit serum, deficient in C'6 can be used as a source of C' components. Treatment of EAC' with EDTA does not modify its leukocyte-adherence properties. The adherence of EAC' to the leukocytes is not inhibited in the presence of serum. The receptors for C' on macrophages, PMN, and monocytes differ from those found on lymphocytes. Rosette formation by EAC' on macrophages, PMN, and monocytes depends on divalent cations (Mg++) and can be reversed by Na3H EDTA, while adherence to lymphocytes is independent of these ions and occurs in the presence of 0.01 M Na3H EDTA. Both types of receptors for C' components are destroyed by trypsin treatment of the leukocytes, in contrast with the receptors for 7S antibodies on the same cells which persist after enzyme treatment.

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