scholarly journals In vivo activation of macrophage C3 receptors for phagocytosis.

1985 ◽  
Vol 162 (1) ◽  
pp. 352-357 ◽  
Author(s):  
F M Griffin ◽  
P J Mullinax
Keyword(s):  
T Lymphocytes ◽  
Immune Complexes ◽  
Fc Receptors ◽  
Peritoneal Macrophages ◽  
Fc Receptor ◽  
Athymic Mice ◽  
Receptor Function ◽  
C3 Receptors

We assessed the effects of exposure to immune complexes in vivo on macrophages' Fc receptor function and C3 receptor function. Peritoneal macrophages from mice injected intraperitoneally with immune complexes were markedly impaired in their ability to phagocytize via their Fc receptors but had acquired the ability to phagocytize via their C3 receptors. In vivo activation of macrophages' C3 receptors for phagocytosis required T lymphocytes, because macrophages from athymic mice could not be activated by injection of immune complexes. The requirement for both T lymphocytes and immune complexes for activation of macrophages' C3 receptors in vivo is identical to the requirements for activation of macrophages' C3 receptors in vitro, suggesting that the mechanisms we have identified for activation of these receptors in vitro are the same mechanisms by which the receptors are activated for phagocytosis in vivo. The susceptibility of macrophages' Fc receptors to blockade by immune complexes and the activation of their C3 receptors for phagocytosis in a milieu containing immune complexes suggest that it may be macrophages' C3 receptors, not their Fc receptors, that are primarily responsible for promoting phagocytosis of opsonized microorganisms in immune hosts.

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 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 Inhibition of Interleukin 10 Signaling after Fc Receptor Ligation and during Rheumatoid Arthritis

2003 ◽  
Vol 197 (11) ◽  
pp. 1573-1583 ◽  
Author(s):  
Jong-Dae Ji ◽  
Ioannis Tassiulas ◽  
Kyung-Hyun Park-Min ◽  
Ani Aydin ◽  
Ingrid Mecklenbräuker ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Immune Complexes ◽  
Inflammatory Responses ◽  
Fc Receptors ◽  
Interleukin 10 ◽  
Interferon Γ ◽  
Fc Receptor ◽  
Receptor Expression ◽  
Inflammatory Factors

Interleukin-10 (IL-10) is a potent deactivator of myeloid cells that limits the intensity and duration of immune and inflammatory responses. The activity of IL-10 can be suppressed during inflammation, infection, or after allogeneic tissue transplantation. We investigated whether inflammatory factors suppress IL-10 activity at the level of signal transduction. Out of many factors tested, only ligation of Fc receptors by immune complexes inhibited IL-10 activation of the Jak-Stat signaling pathway. IL-10 signaling was suppressed in rheumatoid arthritis joint macrophages that are exposed to immune complexes in vivo. Activation of macrophages with interferon-γ was required for Fc receptor–mediated suppression of IL-10 signaling, which resulted in diminished activation of IL-10–inducible genes and reversal of IL-10–dependent suppression of cytokine production. The mechanism of inhibition involved decreased cell surface IL-10 receptor expression and Jak1 activation and was dependent on protein kinase C delta. These results establish that IL-10 signaling is regulated during inflammation and identify Fc receptors and interferon-γ as important regulators of IL-10 activity. Generation of macrophages refractory to IL-10 can contribute to pathogenesis of inflammatory and infectious diseases characterized by production of interferon-γ and immune complexes.

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.

scholarly journals Modulation of Immune Complex–induced Inflammation In Vivo by the Coordinate Expression of Activation and Inhibitory Fc Receptors

1999 ◽  
Vol 189 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Raphael Clynes ◽  
Jay S. Maizes ◽  
Rodolphe Guinamard ◽  
Masao Ono ◽  
Toshiyuki Takai ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Immune Complexes ◽  
Inflammatory Responses ◽  
Fc Receptors ◽  
Inflammatory Cells ◽  
Neutrophil Infiltration ◽  
Calcium Flux ◽  
Deficient Mice

Autoantibodies and immune complexes are major pathogenic factors in autoimmune injury, responsible for initiation of the inflammatory cascade and its resulting tissue damage. This activation results from the interaction of immunoglobulin (Ig)G Fc receptors containing an activation motif (ITAM) with immune complexes (ICs) and cytotoxic autoantibodies which initiates and propagates an inflammatory response. In vitro, this pathway can be interrupted by coligation to FcγRIIB, an IgG Fc receptor containing an inhibitory motif (ITIM). In this report, we describe the in vivo consequences of FcγRII deficiency in the inflammatory response using a mouse model of IC alveolitis. At subthreshold concentrations of ICs that fail to elicit inflammatory responses in wild-type mice, FcγRII-deficient mice developed robust inflammatory responses characterized by increased hemorrhage, edema, and neutrophil infiltration. Bronchoalveolar fluids from FcγRII−/− stimulated mice contain higher levels of tumor necrosis factor and chemotactic activity, suggesting that FcγRII deficiency lowers the threshold of IC stimulation of resident cells such as the alveolar macrophage. In contrast, complement- and complement receptor–deficient mice develop normal inflammatory responses to suprathreshold levels of ICs, while FcRγ−/− mice are completely protected from inflammatory injury. An inhibitory role for FcγRII on macrophages is demonstrated by analysis of FcγRII−/− macrophages which show greater phagocytic and calcium flux responses upon FcγRIII engagement. These data reveal contrasting roles for the cellular receptors for IgG on inflammatory cells, providing a regulatory mechanism for setting thresholds for IC sensitivity based on the ratio of ITIM to ITAM FcγR expression. Exploiting the FcγRII inhibitory pathway could thus provide a new therapeutic approach for modulating antibody-triggered inflammation.

scholarly journals The concentration of IgG in the serum is a major determinant of Fc- dependent reticuloendothelial function

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 490-495 ◽  
Author(s):  
JG Kelton ◽  
J Singer ◽  
C Rodger ◽  
J Gauldie ◽  
P Horsewood ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Immune Complexes ◽  
Fc Receptors ◽  
Secondary Effect ◽  
Macrophage Receptors ◽  
Healthy Control ◽  
Rapid Clearance ◽  
High Concentrations

Abstract Defective Fc receptor-specific reticuloendothelial (RE) function has been reported in certain patients with a variety of immunologic and nonimmunologic diseases. The mechanism responsible for the impaired RE function is uncertain, but it could be caused by immune complexes that are present in many of these disorders. Alternatively, the impaired RE function could be a secondary effect of the high concentrations of monomeric IgG in the serum of these patients, since monomeric IgG can compete with complexed IgG for macrophage receptors in vitro. We studied the Fc-dependent RE function in 30 healthy control subjects and 27 patients using IgG-coated radiolabeled autologous red cells. There was a significant relationship between the concentration of IgG in the serum and the rate of clearance of antibody-sensitized cells (r = 0.51, P less than .01). Patients with hypergammaglobulinemia had the slowest Fc-dependent clearance, whereas those with hypogammaglobulinemia had the most rapid clearance. Immune complexes (Raji or polyethylene glycol) could not be shown to contribute to Fc-dependent RE clearance above the effect of the IgG in the serum. The unusually rapid clearance in a patient with hypogammaglobulinemia could be returned to normal by raising the concentration of IgG in the serum. This study supports the concept that serum (monomeric) IgG competes with immune complexed IgG for macrophage Fc receptors in vivo. The competition for Fc receptors determines the level of competence of Fc-dependent RE function. Based on the results of this study, one can predict that a number of disorders characterized by hypergammaglobulinemia also will have impaired Fc-dependent RE function.

Platelet Fc Receptor as a Mechanism for Ag-Ab Complex-induced Platelet Injury

1973 ◽  
Vol 29 (02) ◽  
pp. 434-444 ◽  
Author(s):  
E.D Israels ◽  
G Nisli ◽  
F Paraskevas ◽  
L.G Israels
Keyword(s):  
Platelet Aggregation ◽  
Immune Complexes ◽  
Test System ◽  
Fc Receptor ◽  
Rabbit Platelet ◽  
Immune Adherence ◽  
Platelet Receptor ◽  
Antigen Antibody

SummaryAntigen-antibody complexes immunologically unrelated to platelet antigens may produce thrombocytopenia in vivo and platelet aggregation and release in vitro. An in vitro platelet system (rabbit and human) was used to study the platelet receptor that mediates the attachment of the immune complex. Platelet aggregation induced by 7 S immune complexes or aggregated gammaglobulin was blocked by prior exposure of the platelet to isolated antibody Fc. Fab from the same antibody was not inhibitory. 5S complexes lacking the Fc piece did not produce aggregation. Serum, as a source of complement was included in the rabbit platelet test system. However, the role of complement is thought to be secondary as it did not bind to platelets in the absence of 7 S complexes and was fixed only secondarily to 7 S binding. On the basis of these studies it is suggested that the platelet membrane contains an Fc receptor and that the primary fixing of immune complexes to the platelet is through the antibody Fc rather than by complement mediated non-specific immune adherence. Antibody Fc fixation to the Fc receptor site of the platelet is probably the common pathway for platelet injury induced by a number of antigen-antibody complexes immunologically unrelated to the platelet.

scholarly journals The concentration of IgG in the serum is a major determinant of Fc- dependent reticuloendothelial function

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 490-495
Author(s):  
JG Kelton ◽  
J Singer ◽  
C Rodger ◽  
J Gauldie ◽  
P Horsewood ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Immune Complexes ◽  
Fc Receptors ◽  
Secondary Effect ◽  
Macrophage Receptors ◽  
Healthy Control ◽  
Rapid Clearance ◽  
High Concentrations

Defective Fc receptor-specific reticuloendothelial (RE) function has been reported in certain patients with a variety of immunologic and nonimmunologic diseases. The mechanism responsible for the impaired RE function is uncertain, but it could be caused by immune complexes that are present in many of these disorders. Alternatively, the impaired RE function could be a secondary effect of the high concentrations of monomeric IgG in the serum of these patients, since monomeric IgG can compete with complexed IgG for macrophage receptors in vitro. We studied the Fc-dependent RE function in 30 healthy control subjects and 27 patients using IgG-coated radiolabeled autologous red cells. There was a significant relationship between the concentration of IgG in the serum and the rate of clearance of antibody-sensitized cells (r = 0.51, P less than .01). Patients with hypergammaglobulinemia had the slowest Fc-dependent clearance, whereas those with hypogammaglobulinemia had the most rapid clearance. Immune complexes (Raji or polyethylene glycol) could not be shown to contribute to Fc-dependent RE clearance above the effect of the IgG in the serum. The unusually rapid clearance in a patient with hypogammaglobulinemia could be returned to normal by raising the concentration of IgG in the serum. This study supports the concept that serum (monomeric) IgG competes with immune complexed IgG for macrophage Fc receptors in vivo. The competition for Fc receptors determines the level of competence of Fc-dependent RE function. Based on the results of this study, one can predict that a number of disorders characterized by hypergammaglobulinemia also will have impaired Fc-dependent RE function.

scholarly journals Design of a multi-epitope vaccine against cervical cancer using immunoinformatics approaches

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samira Sanami ◽  
Fatemeh Azadegan-Dehkordi ◽  
Mahmoud Rafieian-Kopaei ◽  
Majid Salehi ◽  
Maryam Ghasemi-Dehnoo ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
T Lymphocytes ◽  
Tertiary Structure ◽  
Therapeutic Vaccine ◽  
Epitope Prediction ◽  
Therapeutic Effects ◽  
Epitope Vaccine ◽  
In Vivo Experiments

AbstractCervical cancer, caused by human papillomavirus (HPV), is the fourth most common type of cancer among women worldwide. While HPV prophylactic vaccines are available, they have no therapeutic effects and do not clear up existing infections. This study aims to design a therapeutic vaccine against cervical cancer using reverse vaccinology. In this study, the E6 and E7 oncoproteins from HPV16 were chosen as the target antigens for epitope prediction. Cytotoxic T lymphocytes (CTL) and helper T lymphocytes (HTL) epitopes were predicted, and the best epitopes were selected based on antigenicity, allergenicity, and toxicity. The final vaccine construct was composed of the selected epitopes, along with the appropriate adjuvant and linkers. The multi-epitope vaccine was evaluated in terms of physicochemical properties, antigenicity, and allergenicity. The tertiary structure of the vaccine construct was predicted. Furthermore, several analyses were also carried out, including molecular docking, molecular dynamics (MD) simulation, and in silico cloning of the vaccine construct. The results showed that the final proposed vaccine could be considered an effective therapeutic vaccine for HPV; however, in vitro and in vivo experiments are required to validate the efficacy of this vaccine candidate.

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