scholarly journals Fc receptor-mediated phagocytosis occurs in macrophages at exceedingly low cytosolic Ca2+ levels.

1988 ◽  
Vol 106 (3) ◽  
pp. 657-666 ◽  
Author(s):  
F Di Virgilio ◽  
B C Meyer ◽  
S Greenberg ◽  
S C Silverstein
Keyword(s):  
Direct Evidence ◽  
Fc Receptors ◽  
Peritoneal Macrophages ◽  
Fc Receptor ◽  
Fura 2 ◽  
Monolayer Cultures ◽  
Low Concentrations ◽  
High Concentrations ◽  
Macrophage Populations ◽  
Mouse Peritoneal Macrophages

Cytosolic free Ca2+ ([Ca2+]i) homeostasis was investigated in mouse peritoneal macrophages and in the macrophage-like cell line J774. [Ca2+]i measurements were performed in both cells in suspension and cells in monolayers loaded with either quin2 or fura-2. Resting [Ca2+]i was 110-140 and 85-120 nM for cell suspensions and monolayers, respectively. There were no significant differences in [Ca2+]i between the two macrophage populations whether quin2 or fura-2 were used as Ca2+ indicators. Addition of heat-aggregated IgG, IgG-coated erythrocyte ghosts, or a rat monoclonal antibody (2.4G2) directed against mouse Fc receptor II induced a rise in [Ca2+]i. This [Ca2+]i increase was consistently observed in J774 and peritoneal macrophage suspensions and in J774 macrophage monolayers; in contrast it was observed inconsistently in peritoneal macrophages in monolayer cultures. The increase in [Ca2+]i induced by ligation of Fc receptors was inhibited totally in macrophages in suspension and by 80% in macrophages in monolayers by a short preincubation of macrophages with PMA; however, phagocytosis itself was unaffected. The effect of reducing cytosolic Ca2+ to very low concentrations on Fc receptor-mediated phagocytosis was also investigated. By incubating macrophages with high concentrations of quin2/AM in the absence of extracellular Ca2+, or by loading EGTA into the cytoplasm, the [Ca2+]i was buffered and clamped to 1-10 nM. Despite this, the phagocytosis of IgG-coated erythrocytes proceeded normally. These observations confirm the report of Young et al. (Young, J. D., S. S. Ko, and Z. A. Cohn. 1984. Proc. Natl. Acad. Sci. USA. 81:5430-5434) that ligation of Fc receptors causes Ca2+ mobilization in macrophages. However, these results confirm and extend the findings of McNeil et al. (McNeil, P. L., J. A. Swanson, S. D. Wright, S. C. Silverstein, and D. L. Taylor. 1986. J. Cell Biol. 102:1586-1592) that a rise in [Ca2+]i is not required for Fc receptor-mediated phagocytosis; and they provide direct evidence that Fc receptor-mediated phagocytosis occurs normally even at exceedingly low [Ca2+]i.

scholarly journals Structural evidence for distinct IgG subclass-specific Fc receptors on mouse peritoneal macrophages

1980 ◽  
Vol 152 (5) ◽  
pp. 1147-1161 ◽  
Author(s):  
BC Lane ◽  
J Kan-Mitchell ◽  
MS Mitchell ◽  
SM Cooper
Keyword(s):  
Binding Proteins ◽  
Sodium Dodecyl ◽  
Fc Receptors ◽  
Peritoneal Macrophages ◽  
Fc Receptor ◽  
Rabbit Igg ◽  
Mouse Macrophages ◽  
Specific Proteins ◽  
Sepharose 4B ◽  
Mouse Peritoneal Macrophages

Membrane proteins which selectively bind to the Fc portion of IgG were identified in the Nonidet P-40 extracts of radiolabeled thioglycollate- elicited mouse peritoneal macrophages. Affinity columns of various IgG preparations coupled to Sepharose 4B were used to absorb the Fc-binding proteins. Analysis of the acetic acid or sodium dodecyl sulfate (SDS) eluates from aggregated human IgG or antigen-complexed rabbit IgG columns revealed two Fc(gamma)/-specific proteins with apparent 67,000 and 52,000 mol wt. These proteins were not detected in acid or SDS eluates from F(ab')(2) columns or in eluates from IgG column, over which were passed lysates of Fc receptor-negative cells. With the use of affinity columns that contained aggregated mouse myeloma proteins of different IgG subclasses, we found that the 67,000-dahon protein selectively binds to IgG2a, whereas the 52,000-dalton protein binds to IgG1 and IgG2b. Neither protein was found in SDS eluates from IgG3 columns. Trypsin treatment of the macrophages before detergent lysis removed the 67,000-dalton protein, although it leaves intact the 52,000-dalton protein. These results provide structural confirmation for the existence of separate Fc receptors on mouse macrophages and indicate that the two Fc-binding proteins identified in this study represent all or part of the trypsin- sensitive Fc receptor which binds IgG2a and the trypsin-resistant Fc receptor which binds IgG2b and IgG1.

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 of the macrophage complement receptor. Alteration of receptor function upon macrophage activation.

1975 ◽  
Vol 141 (6) ◽  
pp. 1278-1290 ◽  
Author(s):  
C Bianco ◽  
F M Griffin ◽  
S C Silverstein
Keyword(s):  
Macrophage Activation ◽  
Quantitative Difference ◽  
Qualitative Difference ◽  
Fc Receptors ◽  
Significant Degree ◽  
Peritoneal Macrophages ◽  
Fc Receptor ◽  
Complement Receptor ◽  
Complement Receptors ◽  
Activated Macrophages

We have examined the roles of Fc receptors and complement receptors in mediating the interaction of sensitized sheep erythrocytes (E) with activated and with nonactivated mouse peritoneal macrophages. Both activated and nonactivated macrophages ingest IgG-coated erythrocytes [E(IgG)]; activated cells intest 1.5-2 times as man E(IgG) as do nonactivated macrophages. Thus, there is a quantitative difference in Fc receptor-mediated ingestion between activated and nonactivated macrophages. There is, however, a qualitative difference in function of complement receptors of activated and nonactivated macrophages. Nonactivated macrophages avidly bind complement-coated E [E(IgM)Ia1, but do not ingest them to a significant degree. Activated macrophages, on the other hand, bind and ingest E(IgM)C. The possibility of Fc receptor participation in mediating ingestion of E(IgM)C by activated macrophages was eliminated by blocking Fc receptors with an antimacrophage IgG fraction. Activated macrophages treated with antimacrophage IgG did not ingest E(igG) but did ingest both E(IgM)C AND E(IgM)C. Nonactivated macrophages treated with antimacrophage IgG did not interact at all with E(IgG). These cells bound, but did not ingest, E(IgM)C and E(IgM)C. Complement receptor-mediated ingestion is a marker for macrophage activation and may be physiologically important in the elimination of complement-coated particles.

scholarly journals THE INTERACTION IN VITRO OF MYCOPLASMA PULMONIS WITH MOUSE PERITONEAL MACROPHAGES AND L-CELLS

1971 ◽  
Vol 133 (2) ◽  
pp. 231-259 ◽  
Author(s):  
Thomas C. Jones ◽  
James G. Hirsch
Keyword(s):  
Tritiated Thymidine ◽  
Calf Serum ◽  
Peritoneal Macrophages ◽  
Mycoplasma Pulmonis ◽  
Cultural Conditions ◽  
Low Concentrations ◽  
Mouse Macrophages ◽  
Similar Growth ◽  
Mouse Peritoneal Macrophages

Methods have been devised for establishing infection in vitro of mouse macrophages and fibroblasts with Mycoplasma pulmonis. The mycoplasmas attached to the cells and under appropriate cultural conditions grew into a lawn of microorganisms covering most of the cell surface. The mycoplasmas grew abundantly on fibroblasts cultured in minimal essential medium containing 20% fetal calf serum; supplementation of this medium with heart infusion broth was necessary to obtain similar growth on macrophages. The infection of these cells appeared to be essentially an extracellular process; only rarely were partially degraded mycoplasmas seen with phagocytic vacuoles. The addition to heavily infected macrophage cultures of low concentrations of anti-mycoplasma antibody stimulated rapid, massive phagocytosis of the surface microorganisms. In sharp contrast, the same antiserum had no discernable effect on the mycoplasma-fibroblast relationship. The antibody effect in the macrophage system was apparently a direct opsonic one rather than an indirect result of microbial killing, since the mycoplasmas in macrophage or fibroblast cultures incorporated labelled thymidine into DNA after the addition of antiserum to the medium. The phagocytic event and the subsequent fate of the mycoplasmas were studied in detail after the addition of antibody to the macrophage cultures. Phase-contrast cinemicrophotography revealed membrane ruffles surrounding the surface mycoplasmas and disappearance from view of the organisms; 10–30 min later translucent grapelike clusters were seen in large phagocytic vacuoles. On electronmicroscopic study the surface mycoplasmas were surrounded by pincers-like projections of the macrophage. Numerous mycoplasmas were seen in phagocytic vacuoles; in the early minutes after the addition of antibody the intracellular mycoplasmas appeared normal, but within 2 hr they appeared partially degraded with a central electron-lucent area and electron-opaque deposits at the microbial cell margin. 24 hr after the addition of antiserum, digestion of the mycoplasmas was nearly complete; the cells appeared normal except for large residual bodies composed of amorphous moderately dense material and increased lipid deposits. Degradation of mycoplasmas within macrophages was also studied using infected cultures in which the mycoplasmas, but not the macrophages, had incorporated tritiated thymidine into DNA. The appearance of large amounts of acid-soluble radiolabel after phagocytosis stimulated by antibody confirmed the degradation of the intracellular mycoplasmas.

scholarly journals Antileishmanial Activity of a Linalool-Rich Essential Oil from Croton cajucara

2003 ◽  
Vol 47 (6) ◽  
pp. 1895-1901 ◽  
Author(s):  
Maria do Socorro S. Rosa ◽  
Ricardo R. Mendonça-Filho ◽  
Humberto R. Bizzo ◽  
Igor de Almeida Rodrigues ◽  
Rosangela Maria A. Soares ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Essential Oil ◽  
Mammalian Cells ◽  
Morphological Changes ◽  
Peritoneal Macrophages ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Mouse Peritoneal Macrophages ◽  
Croton Cajucara

ABSTRACT The in vitro leishmanicidal effects of a linalool-rich essential oil from the leaves of Croton cajucara against Leishmania amazonensis were investigated. Morphological changes in L. amazonensis promastigotes treated with 15 ng of essential oil per ml were observed by transmission electron microscopy; leishmanial nuclear and kinetoplast chromatin destruction, followed by cell lysis, was observed within 1 h. Pretreatment of mouse peritoneal macrophages with 15 ng of essential oil per ml reduced by 50% the interaction between these macrophages and L. amazonensis, with a concomitant increase by 220% in the level of nitric oxide production by the infected macrophages. Treatment of preinfected macrophages with 15 ng of essential oil per ml reduced by 50% the interaction between these cells and the parasites, which led to a 60% increase in the amount of nitric oxide produced by the preinfected macrophages. These results provide new perspectives on the development of drugs with activities against Leishmania, as linalool-rich essential oil is a strikingly potent leishmanicidal plant extract (50% lethal doses, 8.3 ng/ml for promastigotes and 8.7 ng/ml for amastigotes) which inhibited the growth of L. amazonensis promastigotes at very low concentrations (MIC, 85.0 pg/ml) and which presented no cytotoxic effects against mammalian cells.

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 Regulation of macrophage eicosanoid production by hydroperoxy-and hydroxy-eicosatetraenoic acids

1986 ◽  
Vol 233 (1) ◽  
pp. 199-206 ◽  
Author(s):  
J L Humes ◽  
E E Opas ◽  
M Galavage ◽  
D Soderman ◽  
R J Bonney
Keyword(s):  
Cell Culture ◽  
Arachidonic Acid ◽  
Peritoneal Macrophages ◽  
Lipoxygenase Pathway ◽  
Reversible Inhibitors ◽  
Irreversible Inhibitors ◽  
Intracellular Regulation ◽  
Macrophage Populations ◽  
Mouse Peritoneal Macrophages ◽  
Hydroxyeicosatetraenoic Acids

Resident mouse peritoneal macrophages when exposed to zymosan during the first day of cell culture synthesize and secrete large amounts of prostaglandin E2 (PGE2) and leukotriene C4 (LTC4), the respective products of cyclo-oxygenase- and 5-lipoxygenase-catalysed oxygenations of arachidonic acid. Under these conditions of cell stimulation only small amounts of hydroxyeicosatetraenoic acids (HETEs) are concomitantly produced. However, exogenously added arachidonic acid is metabolized to large amounts of 12- and 15-HETE and only relatively small amounts of PGE2. No LTC4 is formed under these conditions. In contrast, resident mouse peritoneal macrophages in cell culture for 4 days synthesized less PGE2 and LTC4 when exposed to zymosan. However, these macrophage populations continue to synthesize 12-HETE from exogenously added arachidonic acid. Zymosan induced the secretion of a lysosomal enzyme, N-acetyl-beta-glucosaminidase, equally in both 1- and 4-day cultures. Both 12- and 15-hydroperoxyeicosatetraenoic acids (HPETEs), the precursors of 12- and 15-HETE, were found to be irreversible inhibitors of the cyclo-oxygenase pathway and reversible inhibitors of the 5-lipoxygenase pathway in macrophages. 15-HETE were found to be reversible inhibitors of both pathways. Thus the oxidation of arachidonic oxidation of arachidonic acid to both prostaglandins and leukotrienes may be under intracellular regulation by products of 12- and 15-lipoxygenases.

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