scholarly journals Activated Platelets Induce an Anti-Inflammatory Response of Monocytes/Macrophages through Cross-Regulation of PGE2and Cytokines

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Bona Linke ◽  
Yannick Schreiber ◽  
Bettina Picard-Willems ◽  
Patrick Slattery ◽  
Rolf M. Nüsing ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Innate Immune ◽  
Prostaglandin E ◽  
Murine Bone Marrow ◽  
Activated Platelets ◽  
Monocytes And Macrophages ◽  
Inflammatory Processes ◽  
Necrosis Factor

Platelets are well known for their role in hemostasis and are also increasingly recognized for their roles in the innate immune system during inflammation and their regulation of macrophage activation. Here, we aimed to study the influence of platelets on the production of inflammatory mediators by monocytes and macrophages. Analyzing cocultures of platelets and murine bone marrow-derived macrophages or human monocytes, we found that collagen-activated platelets release high amounts of prostaglandin E2(PGE2) that leads to an increased interleukin- (IL-) 10 release and a decreased tumor necrosis factor (TNF)αsecretion out of the monocytes or macrophages. Platelet PGE2mediated the upregulation of IL-10 in both cell types via the PGE2receptor EP2. Notably, PGE2-mediated IL-10 synthesis was also mediated by EP4 in murine macrophages. Inhibition of TNFαsynthesis via EP2 and EP4, but not EP1, was mediated by IL-10, since blockade of the IL-10 receptor abolished the inhibitory effect of both receptors on TNFαrelease. This platelet-mediated cross-regulation between PGE2and cytokines reveals one mechanism how monocytes and macrophages can attenuate excessive inflammatory responses induced by activated platelets in order to limit inflammatory processes.

scholarly journals Phagocytosis and activation of bone marrow‐derived macrophages by Plasmodium falciparum gametocytes

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yolanda Corbett ◽  
Silvia Parapini ◽  
Federica Perego ◽  
Valeria Messina ◽  
Serena Delbue ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bone Marrow ◽  
Plasmodium Falciparum ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Murine Bone Marrow ◽  
Inflammatory Protein ◽  
Life Cycle Stages ◽  
Cytokine Levels ◽  
Necrosis Factor

Abstract Background The innate immune response against various life cycle stages of the malaria parasite plays an important role in protection against the disease and regulation of its severity. Phagocytosis of asexual erythrocytic stages is well documented, but little and contrasting results are available about phagocytic clearance of sexual stages, the gametocytes, which are responsible for the transmission of the parasites from humans to mosquitoes. Similarly, activation of host macrophages by gametocytes has not yet been carefully addressed. Methods Phagocytosis of early or late Plasmodium falciparum gametocytes was evaluated through methanol fixed cytospin preparations of immortalized mouse C57Bl/6 bone marrow-derived macrophages treated for 2 h with P. falciparum and stained with Giemsa, and it was confirmed through a standardized bioluminescent method using the transgenic P. falciparum 3D7elo1-pfs16-CBG99 strain. Activation was evaluated by measuring nitric oxide or cytokine levels in the supernatants of immortalized mouse C57Bl/6 bone marrow-derived macrophages treated with early or late gametocytes. Results The results showed that murine bone marrow-derived macrophages can phagocytose both early and late gametocytes, but only the latter were able to induce the production of inflammatory mediators, specifically nitric oxide and the cytokines tumour necrosis factor and macrophage inflammatory protein 2. Conclusions These results support the hypothesis that developing gametocytes interact in different ways with innate immune cells of the host. Moreover, the present study proposes that early and late gametocytes act differently as targets for innate immune responses.

scholarly journals Inflammation and the Gut-Liver Axis in the Pathophysiology of Cholangiopathies

2018 ◽  
Vol 19 (10) ◽  
pp. 3003 ◽  
Author(s):  
Debora Giordano ◽  
Claudio Pinto ◽  
Luca Maroni ◽  
Antonio Benedetti ◽  
Marco Marzioni
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Enterohepatic Circulation ◽  
Intestinal Barrier ◽  
Cell Types ◽  
Innate Immune ◽  
Primary Biliary Cholangitis ◽  
Innate Immune Responses ◽  
Adaptive Immune Cells ◽  
Bacterial Products

Cholangiocytes, the epithelial cells lining the bile ducts, represent the unique target of a group of progressive diseases known as cholangiopathies whose pathogenesis remain largely unknown. In normal conditions, cholangiocytes are quiescent and participate to the final bile volume and composition. Following exogenous or endogenous stimuli, cholangiocytes undergo extensive modifications of their phenotype. Reactive cholangiocytes actively proliferate and release a set of proinflammatory molecules, which act in autocrine/paracrine manner mediating the cross-talk with other liver cell types and innate and adaptive immune cells. Cholangiocytes themselves activate innate immune responses against gut-derived microorganisms or bacterial products that reach the liver via enterohepatic circulation. Gut microbiota has been implicated in the development and progression of the two most common cholangiopathies, i.e., primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), which have distinctive microbiota composition compared to healthy individuals. The impairment of intestinal barrier functions or gut dysbiosis expose cholangiocytes to an increasing amount of microorganisms and may exacerbate inflammatory responses thus leading to fibrotic remodeling of the organ. The present review focuses on the complex interactions between the activation of innate immune responses in reactive cholangiocytes, dysbiosis, and gut permeability to bacterial products in the pathogenesis of PSC and PBC.

scholarly journals P-selectin mediates Ca(2+)-dependent adhesion of activated platelets to many different types of leukocytes: detection by flow cytometry

Blood ◽  
1992 ◽  
Vol 80 (1) ◽  
pp. 134-142 ◽  
Author(s):  
LG de Bruijne-Admiraal ◽  
PW Modderman ◽  
AE Von dem Borne ◽  
A Sonnenberg
Keyword(s):  
T Cells ◽  
Divalent Cations ◽  
Phosphatidyl Inositol ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Immunofluorescence Assay ◽  
Cd8 Cells ◽  
Activated Platelets ◽  
Selectin Ligands ◽  
Different Types

Abstract Previous studies have shown that thrombin-activated platelets interact through the P-selectin with neutrophils and monocytes. To identify other types of leukocytes capable of such an interaction, eosinophils, basophils, and lymphocytes were isolated from whole blood. Binding of these cells to activated platelets was examined in a double immunofluorescence assay and the results show that activated platelets not only bind to neutrophils and monocytes, but also to eosinophils, basophils, and subpopulations of T lymphocytes. Using monoclonal antibodies (MoAbs) specific for subsets of T cells, we could further demonstrate that the T cells which bind activated platelets are natural killer (NK) cells and an undefined subpopulation of CD4+ and CD8+ cells. All these interactions were dependent on divalent cations and were completely inhibited by an MoAb against P-selectin. Thus, P- selectin mediates the binding of activated platelets to many different types of leukocytes. Studies with leukocytes treated with proteases or neuraminidase have shown that the structures recognized by P-selectin are glycoproteins carrying sialic acid residues. Because the loss of binding of activated platelets to neuraminidase-treated neutrophils was almost complete, but only partial to treated eosinophils, basophils, and monocytes, the latter cell types may have different P-selectin ligands in addition to those present on neutrophils. We found that two previously identified ligands for P-selectin, the oligosaccharides Le(x) and sialyl-Le(x), had little or no inhibitory effect on adhesion of activated platelets to leukocytes and that binding was not inhibited by MoAbs against these oligosaccharides. In addition, there was no correlation between the expression of Le(x) on several cell types and their capacity to bind activated platelets. In contrast, the expression of sialyl-Le(x) on cells was almost perfectly correlated with their ability to bind activated platelets. Thus, while Le(x) cannot be a major ligand for P-selectin, a possible role for sialyl-Le(x) in P- selectin-mediated adhesion processes cannot be dismissed. Finally, activated platelets were found to bind normally to monocytes and neutrophils of patients with paroxysmal nocturnal hemoglobulinuria (PNH) and to neutrophils from which phosphatidyl inositol (PI)-linked proteins had been removed by glycosylphosphatidyl inositol-specific phospholipase C (GPI-PLC) digestion. This suggests that at least part of the P-selectin ligands on these cells are not GPI-anchored.

scholarly journals Tumor Necrosis Factor (TNF) Receptor Shedding Controls Thresholds of Innate Immune Activation That Balance Opposing TNF Functions in Infectious and Inflammatory Diseases

2004 ◽  
Vol 200 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Sofia Xanthoulea ◽  
Manolis Pasparakis ◽  
Stavroula Kousteni ◽  
Cord Brakebusch ◽  
David Wallach ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Bacterial Infections ◽  
Tumor Necrosis ◽  
Inflammatory Responses ◽  
Endotoxic Shock ◽  
Innate Immune ◽  
Disease Assessment ◽  
Recurrent Fever ◽  
Receptor Shedding ◽  
Necrosis Factor

Tumor necrosis factor (TNF) is a potent cytokine exerting critical functions in the activation and regulation of immune and inflammatory responses. Due to its pleiotropic activities, the amplitude and duration of TNF function must be tightly regulated. One of the mechanisms that may have evolved to modulate TNF function is the proteolytic cleavage of its cell surface receptors. In humans, mutations affecting shedding of the p55TNF receptor (R) have been linked with the development of the TNFR-associated periodic syndromes, disorders characterized by recurrent fever attacks and localized inflammation. Here we show that knock-in mice expressing a mutated nonsheddable p55TNFR develop Toll-like receptor–dependent innate immune hyperreactivity, which renders their immune system more efficient at controlling intracellular bacterial infections. Notably, gain of function for antibacterial host defenses ensues at the cost of disbalanced inflammatory reactions that lead to pathology. Mutant mice exhibit spontaneous hepatitis, enhanced susceptibility to endotoxic shock, exacerbated TNF-dependent arthritis, and experimental autoimmune encephalomyelitis. These results introduce a new concept for receptor shedding as a mechanism setting up thresholds of cytokine function to balance resistance and susceptibility to disease. Assessment of p55TNFR shedding may thus be of prognostic value in infectious, inflammatory, and autoimmune diseases.

scholarly journals Modulation of macrophage activation by prostaglandins

1996 ◽  
Vol 5 (1) ◽  
pp. 14-17 ◽  
Author(s):  
L. Sautebin ◽  
R. Carnuccio ◽  
F. D'Acquisto ◽  
M. Di Rosa
Keyword(s):  
Nitric Oxide ◽  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Prostaglandin E ◽  
Tumour Necrosis Factor Α ◽  
Nitric Oxide Release ◽  
Factor Α ◽  
Necrosis Factor

The effect of prostaglandtn E2, iloprost and cAMP on both nitric oxide and tumour necrosis factor-α release in J774 macrophages has been studied. Both prostaglandin E2and iloprost inhibited, in a concentration-dependent fashion, the lipopolysaccharide-induced generation of nitric oxide and tumour necrosis factor-α. The inhibitory effect of these prostanoids seems to be mediated by an increase of the second messenger cAMP since it was mimicked by dibutyryl cAMP and potentiated by the selective type IV phosphodiesterase inhibitor RO-20-1724. Our results suggest that the inhibition of nitric oxide release by prostaglandin E2and iloprost in lipopolysaccharide-activated J774 macrophages may be secondary to the inhibition of tumour necrosis factor-α generation, which in turn is likely to be mediated by cAMP.

scholarly journals Recent Advances on the Innate Immune Response to Coxiella burnetii

2021 ◽  
Vol 11 ◽  
Author(s):  
Guido Sireci ◽  
Giusto Davide Badami ◽  
Diana Di Liberto ◽  
Valeria Blanda ◽  
Francesca Grippi ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Coxiella Burnetii ◽  
Q Fever ◽  
Cell Types ◽  
Innate Immune ◽  
Host Cells ◽  
Experimental Systems ◽  
Monocytes And Macrophages ◽  
Review Reports

Coxiella burnetii is an obligate intracellular Gram-negative bacterium and the causative agent of a worldwide zoonosis known as Q fever. The pathogen invades monocytes and macrophages, replicating within acidic phagolysosomes and evading host defenses through different immune evasion strategies that are mainly associated with the structure of its lipopolysaccharide. The main transmission routes are aerosols and ingestion of fomites from infected animals. The innate immune system provides the first host defense against the microorganism, and it is crucial to direct the infection towards a self-limiting respiratory disease or the chronic form. This review reports the advances in understanding the mechanisms of innate immunity acting during C. burnetii infection and the strategies that pathogen put in place to infect the host cells and to modify the expression of specific host cell genes in order to subvert cellular processes. The mechanisms through which different cell types with different genetic backgrounds are differently susceptible to C. burnetii intracellular growth are discussed. The subsets of cytokines induced following C. burnetii infection as well as the pathogen influence on an inflammasome-mediated response are also described. Finally, we discuss the use of animal experimental systems for studying the innate immune response against C. burnetii and discovering novel methods for prevention and treatment of disease in humans and livestock.

Differential gene expressions of NLRC5 signaling pathway in chicken macrophages cells response to Salmonella Enteritidisderived lipopplysaccharides stimulation

2016 ◽  
Author(s):  
Guobin Chang ◽  
Lingling Qiu ◽  
Xiangping Liu ◽  
Zhiteng Li ◽  
Wei Lu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Host Defense ◽  
Inflammatory Responses ◽  
Cell Types ◽  
Innate Immune ◽  
Gene Expressions ◽  
Mhc I ◽  
Chicken Macrophage ◽  
Differential Gene ◽  
Molecular Patterns

As we all known, NLRC5 recognizes intracellular pathogen-associated molecular patterns (PAMPs) and provokes innate immune system. Its role in innate immune response, NF-kB activation and MHC-I expression remains controversial. In the present study, it was detected that differential gene expressions in NLRC5 signaling pathway at 2, 4, 6 and 8 hours after exposure to LPS using qRT-PCR technology, then analyzed its roles in host defense. The results showed that, comparing to control groups, the expression of NLRC5, MHC-I and IL-18 in LPS-treated groups were significantly up-regulated at 2 hours post stimulation (hps), TLR4 and NF-kB showed conspicuously up-regulated at 4 hps, while STAT1 was significantly down-regulated at 8 hps. Collectively, LPS did evoke inflammatory responses and NLRC5 may negatively regulate NF-kB and critically regulate MHC-I to control intracellular PAMPs in chicken macrophage cell line but the specific role of NLRC5 in host defense relates to cell types and species tested.

scholarly journals Inhibitory Effect of Methyleugenol on IgE-Mediated Allergic Inflammation in RBL-2H3 Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Feng Tang ◽  
Feilong Chen ◽  
Xiao Ling ◽  
Yao Huang ◽  
Xiaomei Zheng ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Allergic Inflammation ◽  
Allergic Diseases ◽  
Inhibitory Effect ◽  
Prostaglandin E ◽  
Therapeutic Drugs ◽  
Cytosolic Phospholipase ◽  
Ige Mediated ◽  
Cox 2 ◽  
Mast Cell Line

Allergic diseases, such as asthma and allergic rhinitis, are common. Therefore, the discovery of therapeutic drugs for these conditions is essential. Methyleugenol (ME) is a natural compound with antiallergic, antianaphylactic, antinociceptive, and anti-inflammatory effects. This study examined the antiallergic effect of ME on IgE-mediated inflammatory responses and its antiallergy mechanism in the mast cell line, RBL-2H3. We found that ME significantly inhibited the release ofβ-hexosaminidase, tumor necrosis factor- (TNF-)α, and interleukin- (IL-) 4, and was not cytotoxic at the tested concentrations (0–100 μM). Additionally, ME markedly reduced the production of the proinflammatory lipid mediators prostaglandin E2(PGE2), prostaglandin D2(PGD2), leukotriene B4(LTB4), and leukotriene C4(LTC4). We further evaluated the effect of ME on the early stages of the FcεRI cascade. ME significantly inhibited Syk phosphorylation and expression but had no effect on Lyn. Furthermore, it suppressed ERK1/2, p38, and JNK phosphorylation, which is implicated in proinflammatory cytokine expression. ME also decreased cytosolic phospholipase A2(cPLA2) and 5-lipoxygenase (5-LO) phosphorylation and cyclooxygenase-2 (COX-2) expression. These results suggest that ME inhibits allergic response by suppressing the activation of Syk, ERK1/2, p38, JNK, cPLA2, and 5-LO. Furthermore, the strong inhibition of COX-2 expression may also contribute to the antiallergic action of ME. Our study provides further information about the biological functions of ME.

Cytokine release from innate immune cells: association with diverse membrane trafficking pathways

Blood ◽  
2011 ◽  
Vol 118 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Paige Lacy ◽  
Jennifer L. Stow
Keyword(s):  
Membrane Trafficking ◽  
Immune Cells ◽  
Inflammatory Responses ◽  
Cell Types ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Cytokine Release ◽  
Research Findings ◽  
Specific Receptors ◽  
Different Cell Types

AbstractCytokines released from innate immune cells play key roles in the regulation of the immune response. These intercellular messengers are the source of soluble regulatory signals that initiate and constrain inflammatory responses to pathogens and injury. Although numerous studies describe detailed signaling pathways induced by cytokines and their specific receptors, there is little information on the mechanisms that control the release of cytokines from different cell types. Indeed, the pathways, molecules, and mechanisms of cytokine release remain a “black box” in immunology. Here, we review research findings and new approaches that have begun to generate information on cytokine trafficking and release by innate immune cells in response to inflammatory or infectious stimuli. Surprisingly complex machinery, multiple organelles, and specialized membrane domains exist in these cells to ensure the selective, temporal, and often polarized release of cytokines in innate immunity.

scholarly journals Bcr and Abr Cooperate in Negatively Regulating Acute Inflammatory Responses

2009 ◽  
Vol 29 (21) ◽  
pp. 5742-5750 ◽  
Author(s):  
Jess M. Cunnick ◽  
Sabine Schmidhuber ◽  
Gang Chen ◽  
Min Yu ◽  
Sun-Ju Yi ◽  
...  
Keyword(s):  
Immune System ◽  
Innate Immune System ◽  
Inflammatory Responses ◽  
Small Gtpase ◽  
Innate Immune ◽  
Ros Production ◽  
Activated Neutrophils ◽  
Inflammatory Processes ◽  
Null Mutant Mice

ABSTRACT Bcr and Abr are GTPase-activating proteins for the small GTPase Rac. Both proteins are expressed in cells of the innate immune system, including neutrophils and macrophages. The function of Bcr has been linked to the negative regulation of neutrophil reactive oxygen species (ROS) production, but the function of Abr in the innate immune system was unknown. Here, we report that mice lacking both proteins are severely affected in two models of experimental endotoxemia, including exposure to Escherichia coli lipopolysaccharide and polymicrobial sepsis, with extensive microvascular leakage, resulting in severe pulmonary edema and hemorrhage. Additionally, in vivo-activated neutrophils of abr and bcr null mutant mice produced excessive tissue-damaging myeloperoxidase (MPO), elastase, and ROS. Moreover, the secretion of the tissue metalloproteinase MMP9 by monocytes and ROS by elicited macrophages was abnormally high. In comparison, ROS production from bone marrow monocytes was not significantly different from that of controls, and the exocytosis of neutrophil secondary and tertiary granule products, including lactoferrin, was normal. These data show that Abr and Bcr normally curb very specific functions of mature tissue innate immune cells, and that each protein has distinct as well as partly overlapping functions in the downregulation of inflammatory processes.

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