scholarly journals Regulation of elastase and plasminogen activator secretion in resident and inflammatory macrophages by receptors for the Fc domain of immunoglobulin G.

1984 ◽  
Vol 159 (1) ◽  
pp. 152-166 ◽  
Author(s):  
R Takemura ◽  
Z Werb
Keyword(s):  
Plasminogen Activator ◽  
Control Level ◽  
Fc Receptors ◽  
Fc Receptor ◽  
Complement Receptor ◽  
Complement Receptors ◽  
Membrane Bound ◽  
Inflammatory Macrophages ◽  
Secretion Rates ◽  
Stimulation Of

We have determined that the interaction of IgG-coated erythrocytes (EIgG) and complement-coated erythrocytes (EIgMC) with macrophage Fc and complement receptors, respectively, modulates the secretion of the neutral proteinases, elastase, and plasminogen activator. EIgG binding and ingestion stimulated secretion of elastase and plasminogen activator less than or equal to 6-fold and 20-fold, respectively, over the 3 d following treatment. Stimulation was dependent on the IgG titer bound to each erythrocyte and was detectable at greater than 6.2 X 10(3) molecules IgG/ erythrocyte (total 0.99 nM IgG in the culture). Cytochalasin B did not inhibit stimulation, indicating that the ingestion of ligands was not necessary. Binding of EIgG to the three subclass-specific Fc receptors (IgG2a, IgG2b/IgG1, IgG3) was effective. Stimulation of elastase secretion required continued exposure of ligands to cells for up to 24 h, whereas production of plasminogen activator, which has plasma membrane-bound forms as well as secreted forms, was stimulated by exposure for 2 h. The stimulated production of elastase and plasminogen activator by triggering Fc receptors was seen only when the initial secretion rates were low. Periodate- or thioglycollate-elicited macrophages, which have high rates of proteinase secretion, were not stimulated further. EIgMC, which are bound but not ingested by resident macrophages, stimulated elastase secretion transiently, and the rate of secretion returned to the control level by 24 h. Therefore, the mode of stimulation of neutral proteinase secretion by complement receptor differed from that of Fc receptor; stimulation by complement receptor possibly involves a limited release of enzyme from intracellular stores, rather than stimulating accelerated synthesis of enzyme. Erythrocytes coated with both complement and IgG showed both the transient increase in elastase typical of complement-mediated secretion and the sustained increase typical of Fc receptor-mediated secretion. These results suggest that macrophage Fc and complement receptors regulate secretion of proteinases by receptor-specific mechanisms.

scholarly journals Effects of soluble immune complexes on Fc receptor- and C3b receptor-mediated phagocytosis by macrophages.

1980 ◽  
Vol 152 (4) ◽  
pp. 905-919 ◽  
Author(s):  
F M Griffin
Keyword(s):  
Immune Complexes ◽  
Fc Receptors ◽  
Fc Receptor ◽  
Complement Receptor ◽  
Complement Receptors ◽  
Phagocytic Function ◽  
Receptor Function ◽  
Coated Particles ◽  
C3b Receptor ◽  
Soluble Immune Complexes

The effects of ingestion of soluble immune complexes upon macrophage phagocytic function was studied. Ingestion of immune complexes severely impaired the macrophage's ability to ingest IgG-coated particles but did not alter its ability to interact with particles by means other than its Fc receptors. Treatment of macrophages that had ingested immune complexes with supernates containing the previously described lymphokine that augments macrophage complement receptor function failed to enhance the cells' interaction with either IgG-coated erythrocytes or zymosan particles but markedly enhanced their ability to phagocytize via their complement receptors. The possible significance of these findings in immunologically mediated inflammation is discussed.

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 Augmentation of macrophage complement receptor function in vitro. I. Characterization of the cellular interactions required for the generation of a T-lymphocyte product that enhances macrophage complement receptor function.

1979 ◽  
Vol 150 (3) ◽  
pp. 653-675 ◽  
Author(s):  
J A Griffin ◽  
F M Griffin
Keyword(s):  
T Lymphocytes ◽  
Complex Disease ◽  
Peritoneal Macrophages ◽  
Fc Receptor ◽  
Microbial Pathogens ◽  
Complement Receptor ◽  
Complement Receptors ◽  
Cellular Interactions ◽  
Receptor Function

The function of complement receptors of mouse peritoneal macrophages was converted in vitro from mediating only attachment of macrophage complement receptor function was achieved by treating freshly explanted macrophages with supernates from cultures containing T lymphocytes and appropriately triggered macrophages. Fc receptor-mediated phagocyctosis by macrophages was required for the production of active supernates, for neither ingestion via the cells' complement receptors nor ingestion via nonimmunologic means was a sufficient stimulus for the macrophages' participation in the generation of supernatant activity. Fc receptor-triggered macrophages interacted by a contact dependent, but histocompatibility independent, mechanism with T lymphocytes, thereby signalling the lymphocytes to elaborate the active product. The possible significance of enhanced macrophage complement receptor function in inflammation, host defense against microbial pathogens, immune complex disease, and neoplasia is discussed.

scholarly journals Effects of immobilized immune complexes on Fc- and complement-receptor function in resident and thioglycollate-elicited mouse peritoneal macrophages.

1979 ◽  
Vol 150 (3) ◽  
pp. 607-621 ◽  
Author(s):  
J Michl ◽  
M M Pieczonka ◽  
J C Unkeless ◽  
S C Silverstein
Keyword(s):  
Immune Complexes ◽  
Fc Receptors ◽  
Cell Types ◽  
Peritoneal Macrophages ◽  
Complement Receptor ◽  
Complement Receptors ◽  
Receptor Function ◽  
Rabbit Antibody ◽  
Coated Surfaces ◽  
Mouse Peritoneal Macrophages

We have examined the Fc- and complement-receptor function of resident and thioglycollate-elicited mouse peritoneal macrophages plated on surfaces coated with rabbit antibody-antigen complexes and with complement. We derive four major conclusions from these studies. (a) The trypsin-resistant Fc receptors of resident and thioglycollate-elicited macrophages are completely modulated when these cells are plated on rabbit antibody-antigen complexes. Residual Fc receptor activity is a result of the incomplete modulation of trypsin-sensitive IgG2a receptors. (b) The complement receptors of thioglycollate-elicited macrophages, but not of resident macrophages, are modulated when these cells are plated on complement-coated surfaces. The capacity of the two cell types to modulate their complement receptors is correlated with their ability to ingest complement-coated erythrocytes. (c) The complement and Fc receptors of both types of macrophages move independently of one another. (d) Complement masks the Fc segments of IgG in immune complexes thereby rendering them ineffective as ligands for macrophage Fc receptors.

Adrenergic Stimulation of Regional Plasminogen Activator Release in Rabbits

1992 ◽  
Vol 68 (05) ◽  
pp. 545-549 ◽  
Author(s):  
W L Chandler ◽  
S C Loo ◽  
D Mornin
Keyword(s):  
Lower Extremity ◽  
Plasminogen Activator ◽  
Beta Blocker ◽  
Time Course ◽  
Vascular System ◽  
Adrenergic Stimulation ◽  
Epinephrine Administration ◽  
Adrenergic Antagonist ◽  
Vascular Beds ◽  
Stimulation Of

SummaryThe purpose of this study was to determine whether different regions of the rabbit vascular system show variations in the rate of plasminogen activator (PA) secretion. To start, we evaluated the time course, dose response and adrenergic specificity of PA release. Infusion of 1 µg/kg of epinephrine stimulated a 116 ± 60% (SD) increase in PA activity that peaked 30 to 60 s after epinephrine administration. Infusion of 1 µg/kg of norepinephrine, isoproterenol and phenylephrine had no effect on PA activity. Pretreatment with phentolamine, an alpha adrenergic antagonist, blocked the release of PA by epinephrine while pretreatment with the beta blocker propranolol had no effect. This suggests that PA release in the rabbit was mediated by some form of alpha receptor.Significant arterio-venous differences in basal PA activity were found across the pulmonary and splanchnic vascular beds but not the lower extremity/pelvic bed. After stimulation with epinephrine, PA activity increased 46% across the splanchnic bed while no change was seen across the lower extremity/pelvic bed. We conclude that several vascular beds contribute to circulating PA activity in the rabbit, and that these beds secrete PA at different rates under both basal and stimulated conditions.

scholarly journals Deficiency of decay-accelerating factor and complement receptor 1–related gene/protein y on murine platelets leads to complement-dependent clearance by the macrophage phagocytic receptor CRIg

Blood ◽  
2008 ◽  
Vol 112 (4) ◽  
pp. 1109-1119 ◽  
Author(s):  
David D. Kim ◽  
Takashi Miwa ◽  
Yuko Kimura ◽  
Reto A. Schwendener ◽  
Menno van Lookeren Campagne ◽  
...  
Keyword(s):  
Human Platelets ◽  
Transfer Model ◽  
Complement Receptor ◽  
Dependent Manner ◽  
Complement Receptors ◽  
Related Gene ◽  
Decay Accelerating Factor ◽  
Gene Ablation ◽  
Complement Receptor 1

Abstract Complement activation on human platelets is known to cause platelet degranulation and activation. To evaluate how normal platelets escape complement attack in vivo, we studied the fate of murine platelets deficient in 2 membrane complement regulatory proteins using an adoptive transfer model. We show here that deficiency of either decay-accelerating factor (DAF) or complement receptor 1–related gene/protein y (Crry) on murine platelets was inconsequential, whereas DAF and Crry double deficiency led to rapid clearance of platelets from circu-lation in a complement- and macrophage-dependent manner. This finding contrasted with the observation on erythrocytes, where Crry deficiency alone resulted in complement susceptibility. Quantitative flow cytometry revealed that DAF and Crry were expressed at similar levels on platelets, whereas Crry expression was 3 times higher than DAF on erythrocytes. Antibody blocking or gene ablation of the newly identified complement receptor CRIg, but not complement receptor 3 (CR3), rescued DAF/Crry-deficient platelets from complement-dependent elimination. Surprisingly, deficiency of CRIg, CR3, and other known complement receptors failed to prevent Crry-deficient erythrocytes from complement-mediated clearance. These results show a critical but redundant role of DAF and Crry in platelet survival and suggest that complement-opsonized platelets and erythrocytes engage different complement receptors on tissue macrophages in vivo.

The lymphocyte surface. II. Separation of Fc receptor, C'3 receptor and surface immunoglobulin-bearing lymphocytes

1974 ◽  
Vol 187 (1086) ◽  
pp. 65-81 ◽  
Keyword(s):  
Lymph Nodes ◽  
Thoracic Duct ◽  
Large Population ◽  
Fc Receptors ◽  
Fc Receptor ◽  
Substantial Proportion ◽  
Separation Procedure ◽  
Total Recovery ◽  
Surface Immunoglobulin ◽  
Spleen And Lymph Nodes

A one-step separation procedure is described for both depleting and obtaining in pure form Fc receptor (FcRL), C'3 receptor (CRL) and surface immunoglobulin bearing (IgL) lymphocytes from rat lymphoid populations. The method is a modification of the Bӧyum (1968) technique for separating lymphocytes from whole blood by sedimentation on Ficoll/Isopaque, and is based on the fact that when a lymphocyte forms a rosette with sensitized erythrocytes it will sediment with the red cells rather than float with the non-rosetting lymphocytes. The technique is > 99.5% efficient at depleting thoracic duct lymphocytes (TDL) of FcRL, CRL and IgL and these subpopulations can be recovered 93-98% pure. The total recovery of lymphocytes applied is usually > 90% and the separated lymphocytes are > 95% viable. This technique allowed the cellular distribution of Fc receptors, C'3 receptors and surface Ig to be determined. It was found that ( a ) Almost all CRL carry surface Ig, although a very small sub-population of CRL (0.2-0.8%) which lacks surface Ig could regularly be detected. ( b ) A substantial proportion of IgL (12-25%) lacks C'3 receptors. ( c ) IgL and CRL which lack Fc receptors are more frequent in spleen and lymph nodes than in TDL. The proportion of this subpopulation increases in TDL after prolonged thoracic duct drainage. ( d ) Some FcRL exist which lack both C'3 receptors and surface Ig. These cells are more evident in TDL after prolonged thoracic duct drainage and in lymph nodes (20-30% of FcRL) than in early TDL or spleen (5-10% of FcRL). ( e ) The thymus contains very few FcRL, CRL or IgL. ( f ) A large population of lymphocytes exists in B rats (32-42% of TDL) which is killed by an anti-B serum but which lacks surface Ig. These cells are much less frequent in normal TDL ( < 5%) and probably also lack Fc and C'3 receptors. ( g ) Large lymphocytes probably shed their Fc and C'3 receptors, but retain their surface Ig, during S-phase. ( h ) Studies on a secondary anti-DNP response showed that a substantial proportion of direct and indirect plaque forming cells (PFC) in the spleen express Fc receptors, whereas only indirect PFC carry C'3 receptors. Virtually all PFC ( > 98%) possess surface Ig.

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