Investigating the Role of Surface Materials and Three Dimensional Architecture on In Vitro Differentiation of Porcine Monocyte-Derived Dendritic Cells.

PubMed

Hartmann, Sofie Bruun; Mohanty, Soumyaranjan; Skovgaard, Kerstin; Brogaard, Louise; Flagstad, Frederikke Bjergvang; Emnéus, Jenny; Wolff, Anders; Summerfield, Artur; Jungersen, Gregers

2016-01-01

In vitro generation of dendritic-like cells through differentiation of peripheral blood monocytes is typically done using two-dimensional polystyrene culture plates. In the process of optimising cell culture techniques, engineers have developed fluidic micro-devises usually manufactured in materials other than polystyrene and applying three-dimensional structures more similar to the in vivo environment. Polydimethylsiloxane (PDMS) is an often used polymer for lab-on-a-chip devices but not much is known about the effect of changing the culture surface material from polystyrene to PDMS. In the present study the differentiation of porcine monocytes to monocyte-derived dendritic cells (moDCs) was investigated using CD172apos pig blood monocytes stimulated with GM-CSF and IL-4. Monocytes were cultured on surfaces made of two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS and carbonised three-dimensional PDMS. Cells cultured conventionally (on two-dimensional polystyrene) differentiated into moDCs as expected. Interestingly, gene expression of a wide range of cytokines, chemokines, and pattern recognition receptors was influenced by culture surface material and architecture. Distinct clustering of cells, based on similar expression patterns of 46 genes of interest, was seen for cells isolated from two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS. Changing the material from polystyrene to PDMS resulted in cells with expression patterns usually associated with macrophage expression (upregulation of CD163 and downregulation of CD1a, FLT3, LAMP3 and BATF3). However, this was purely based on gene expression level, and no functional assays were included in this study which would be necessary in order to classify the cells as being macrophages. When changing to three-dimensional culture the cells became increasingly activated in terms of IL6, IL8, IL10 and CCR5 gene expression. Further stimulation with LPS resulted in a slight increase in the expression of maturation markers (SLA-DRB1, CD86 and CD40) as well as cytokines (IL6, IL8, IL10 and IL23A) but the influence of the surfaces was unchanged. These findings highlights future challenges of combining and comparing data generated from microfluidic cell culture-devices made using alternative materials to data generated using conventional polystyrene plates used by most laboratories today.

Role of nanostructured gold surfaces on monocyte activation and Staphylococcus epidermidis biofilm formation

PubMed Central

Svensson, Sara; Forsberg, Magnus; Hulander, Mats; Vazirisani, Forugh; Palmquist, Anders; Lausmaa, Jukka; Thomsen, Peter; Trobos, Margarita

2014-01-01

The role of material surface properties in the direct interaction with bacteria and the indirect route via host defense cells is not fully understood. Recently, it was suggested that nanostructured implant surfaces possess antimicrobial properties. In the current study, the adhesion and biofilm formation of Staphylococcus epidermidis and human monocyte adhesion and activation were studied separately and in coculture in different in vitro models using smooth gold and well-defined nanostructured gold surfaces. Two polystyrene surfaces were used as controls in the monocyte experiments. Fluorescent viability staining demonstrated a reduction in the viability of S. epidermidis close to the nanostructured gold surface, whereas the smooth gold correlated with more live biofilm. The results were supported by scanning electron microscopy observations, showing higher biofilm tower formations and more mature biofilms on smooth gold compared with nanostructured gold. Unstimulated monocytes on the different substrates demonstrated low activation, reduced gene expression of pro- and anti-inflammatory cytokines, and low cytokine secretion. In contrast, stimulation with opsonized zymosan or opsonized live S. epidermidis for 1 hour significantly increased the production of reactive oxygen species, the gene expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-10, as well as the secretion of TNF-α, demonstrating the ability of the cells to elicit a response and actively phagocytose prey. In addition, cells cultured on the smooth gold and the nanostructured gold displayed a different adhesion pattern and a more rapid oxidative burst than those cultured on polystyrene upon stimulation. We conclude that S. epidermidis decreased its viability initially when adhering to nanostructured surfaces compared with smooth gold surfaces, especially in the bacterial cell layers closest to the surface. In contrast, material surface properties neither strongly promoted nor attenuated the activity of monocytes when exposed to zymosan particles or S. epidermidis. PMID:24550671

Gingival Tissue Inflammation Promotes Increased Matrix Metalloproteinase-12 Production by CD200Rlow Monocyte-Derived Cells in Periodontitis.

PubMed

Björnfot Holmström, Sofia; Clark, Reuben; Zwicker, Stephanie; Bureik, Daniela; Kvedaraite, Egle; Bernasconi, Eric; Nguyen Hoang, Anh Thu; Johannsen, Gunnar; Marsland, Benjamin J; Boström, Elisabeth A; Svensson, Mattias

2017-12-15

Irreversible tissue recession in chronic inflammatory diseases is associated with dysregulated immune activation and production of tissue degradative enzymes. In this study, we identified elevated levels of matrix metalloproteinase (MMP)-12 in gingival tissue of patients with the chronic inflammatory disease periodontitis (PD). The source of MMP12 was cells of monocyte origin as determined by the expression of CD14, CD68, and CD64. These MMP12-producing cells showed reduced surface levels of the coinhibitory molecule CD200R. Similarly, establishing a multicellular three-dimensional model of human oral mucosa with induced inflammation promoted MMP12 production and reduced CD200R surface expression by monocyte-derived cells. MMP12 production by monocyte-derived cells was induced by CSF2 rather than the cyclooxygenase-2 pathway, and treatment of monocyte-derived cells with a CD200R ligand reduced CSF2-induced MMP12 production. Further, MMP12-mediated degradation of the extracellular matrix proteins tropoelastin and fibronectin in the tissue model coincided with a loss of Ki-67, a protein strictly associated with cell proliferation. Reduced amounts of tropoelastin were confirmed in gingival tissue from PD patients. Thus, this novel association of the CD200/CD200R pathway with MMP12 production by monocyte-derived cells may play a key role in PD progression and will be important to take into consideration in the development of future strategies to diagnose, treat, and prevent PD. Copyright © 2017 by The American Association of Immunologists, Inc.

Modulation of Fc gamma receptors on I cells and monocytes by 15 hydroperoxyeicosatetranoic acid.

PubMed

Goodwin, J S; Gualde, N; Aldigier, J; Rigaud, M; Vanderhoek, J Y

1984-01-01

We investigated the effects of the 15-lipoxygenase products, 15 hydroperoxyeicosatetranoic acid (15 HPETE) and 15 hydroxyeicosatetranoic acid (15 HETE) on Fc gamma receptor expression on human T cells and monocytes. Incubation of these cells with 15 HPETE but not 15 HETE results in a shift to decreased density of Fc gamma receptors on the cell surface.

Role of CD40 and ADAMTS13 in von Willebrand factor-mediated endothelial cell-platelet-monocyte interaction.

PubMed

Popa, Miruna; Tahir, Sibgha; Elrod, Julia; Kim, Su Hwan; Leuschner, Florian; Kessler, Thorsten; Bugert, Peter; Pohl, Ulrich; Wagner, Andreas H; Hecker, Markus

2018-06-12

Monocyte extravasation into the vessel wall is a key step in atherogenesis. It is still elusive how monocytes transmigrate through the endothelial cell (EC) monolayer at atherosclerosis predilection sites. Platelets tethered to ultra-large von Willebrand factor (ULVWF) multimers deposited on the luminal EC surface following CD40 ligand (CD154) stimulation may facilitate monocyte diapedesis. Human ECs grown in a parallel plate flow chamber for live-cell imaging or Transwell permeable supports for transmigration assay were exposed to fluid or orbital shear stress and CD154. Human isolated platelets and/or monocytes were superfused over or added on top of the EC monolayer. Plasma levels and activity of the ULVWF multimer-cleaving protease ADAMTS13 were compared between coronary artery disease (CAD) patients and controls and were verified by the bioassay. Two-photon intravital microscopy was performed to monitor CD154-dependent leukocyte recruitment in the cremaster microcirculation of ADAMTS13-deficient versus wild-type mice. CD154-induced ULVWF multimer-platelet string formation on the EC surface trapped monocytes and facilitated transmigration through the EC monolayer despite high shear stress. Two-photon intravital microscopy revealed CD154-induced ULVWF multimer-platelet string formation preferentially in venules, due to strong EC expression of CD40, causing prominent downstream leukocyte extravasation. Plasma ADAMTS13 abundance and activity were significantly reduced in CAD patients and strongly facilitated both ULVWF multimer-platelet string formation and monocyte trapping in vitro. Moderate ADAMTS13 deficiency in CAD patients augments CD154-mediated deposition of platelet-decorated ULVWF multimers on the luminal EC surface, reinforcing the trapping of circulating monocytes at atherosclerosis predilection sites and promoting their diapedesis.

Role of monocyte-lineage cells in prostate cancer cell invasion and tissue factor expression.

PubMed

Lindholm, Paul F; Lu, Yi; Adley, Brian P; Vladislav, Tudor; Jovanovic, Borko; Sivapurapu, Neela; Yang, Ximing J; Kajdacsy-Balla, André

2010-11-01

Tissue factor (TF) is a cell surface glycoprotein intricately related to blood coagulation and inflammation. This study was performed to investigate the role of monocyte-lineage cells in prostate cancer cell TF expression and cell invasion. Prostate cancer cell invasion was tested with and without added peripheral blood monocytes or human monocyte-lineage cell lines. TF neutralizing antibodies were used to determine the TF requirement for prostate cancer cell invasion activity. Immunohistochemistry was performed to identify prostate tissue CD68 positive monocyte-derived cells and prostate epithelial TF expression. Co-culture of PC-3, DU145, and LNCaP cells with isolated human monocytes significantly stimulated prostate cancer cell invasion activity. TF expression was greater in highly invasive prostate cancer cells and was induced in PC-3, DU145, and LNCaP cells by co-culture with U-937 cells, but not with THP-1 cells. TF neutralizing antibodies inhibited PC-3 cell invasion in co-cultures with monocyte-lineage U-937 or THP-1 cells. Prostate cancer tissues contained more CD68 positive cells in the stroma and epithelium (145 ± 53/mm(2)) than benign prostate (108 ± 31/mm(2)). Samples from advanced stage prostate cancer tended to contain more CD68 positive cells when compared with lower stage lesions. Prostatic adenocarcinoma demonstrated significantly increased TF expression compared with benign prostatic epithelium. This study shows that co-culture with monocyte-lineage cells induced prostate cancer cell invasion activity. PC-3 invasion and TF expression was induced in co-culture with U-937 cells and partially inhibited with TF neutralizing antibodies.

Elevated concentrations of nonesterified fatty acids increase monocyte expression of CD11b and adhesion to endothelial cells.

PubMed

Zhang, Wei-Yang; Schwartz, Eric; Wang, Yingjie; Attrep, Jeanne; Li, Zhi; Reaven, Peter

2006-03-01

Monocyte proinflammatory activity has been demonstrated in obesity, insulin resistance, and type 2 diabetes, metabolic conditions that are frequently associated with elevated levels of nonesterified fatty acids (NEFA). We therefore tested the hypothesis that NEFA may induce monocyte inflammation. Monocytes exposed to NEFA for 2 days demonstrated a dose-related increase in intracellular reactive oxygen species (ROS) formation and adhesion to endothelial cells. All of these effects were inhibited by the coaddition of antioxidants such as glutathione or butylated hydroxytoluene, by inhibition of ROS generation by NADPH oxidase inhibitors, and by inhibition of protein kinase C, a recognized stimulator of NAPDH oxidase. Monocytes exposed to NEFA also demonstrated a significant increase in CD11b message expression. Stimulation of monocyte adhesion to endothelial cells by NEFA was inhibited by addition of neutralizing antibodies to either CD11b or CD18. Finally, surface expression of CD11b increased significantly on monocytes as measured by flow cytometry, after their incubation with NEFA. These studies indicate that elevated concentrations of NEFA may enhance integrin facilitated monocyte adhesion to endothelial cells and these effects appear mediated, in part, through activation of NADPH oxidase and oxidative stress.

IL-10-dependent down-regulation of MHC class II expression level on monocytes by peritoneal fluid from endometriosis patients.

PubMed

Lee, Kyu-Sup; Baek, Dae-Won; Kim, Ki-Hyung; Shin, Byoung-Sub; Lee, Dong-Hyung; Kim, Ja-Woong; Hong, Young-Seoub; Bae, Yoe-Sik; Kwak, Jong-Young

2005-11-01

Endometriosis is a gynecologic disorder characterized by the ectopic growth of misplaced endometrial cells. Moreover, immunological abnormalities of cell-mediated and humoral immunity may be associated with the pathogenesis of endometriosis. The effects of peritoneal fluid (PF) from endometriosis patients on the expression levels of MHC class II and costimulatory molecules on the cell surfaces of monocytes were investigated. Compared to the PF of controls, the addition of 10% PF (n=10) from patients with endometriosis to culture medium significantly reduced the percentage of MHC class II-positive cells in cultures of a THP-1, monocytic cell line at 48 h. The effect of endometriosis patient PF (EPF) was dose-dependent, and similar effect was observed in peripheral blood monocytes. An inverse correlation was found between MHC class II expression level and IL-10 concentration in EPF (r=-0.518; p=0.019) and in the supernatant of peripheral blood monocyte cultured in EPF (r=-0.459; p=0.042) (n=20). The expression levels of costimulatory molecules (CD80 and CD86), but not of CD54 and B7-H1, were down-regulated by EPF. The mRNA level of HLA-DR was unaffected by EPF but protein level was reduced by EPF. Neutralizing IL-10 antibody abrogated MHC class II down-regulation on monocytes, which had been induced by EPF. However, in a functional assay, monocytes treated with EPF failed to stimulate T cell in mixed leukocyte reaction, although T cell proliferation was increased with EPF-treated monocytes and Staphylococcus enterotoxin B. These results suggest that MHC class II expression level on monocytes is down-regulated by EPF, but the cell stimulatory ability of monocytes does not coincide with MHC class II expression level.

Prion protein induced signaling cascades in monocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krebs, Bjarne; Dorner-Ciossek, Cornelia; Schmalzbauer, Ruediger

2006-02-03

Prion proteins play a central role in transmission and pathogenesis of transmissible spongiform encephalopathies. The cellular prion protein (PrP{sup C}), whose physiological function remains elusive, is anchored to the surface of a variety of cell types including neurons and cells of the lymphoreticular system. In this study, we investigated the response of a mouse monocyte/macrophage cell line to exposure with PrP{sup C} fusion proteins synthesized with a human Fc-tag. PrP{sup C} fusion proteins showed an attachment to the surface of monocyte/macrophages in nanomolar concentrations. This was accompanied by an increase of cellular tyrosine phosphorylation as a result of activated signalingmore » pathways. Detailed investigations exhibited activation of downstream pathways through a stimulation with PrP fusion proteins, which include phosphorylation of ERK{sub 1,2} and Akt kinase. Macrophages opsonize and present antigenic structures, contact lymphocytes, and deliver cytokines. The findings reported here may become the basis of understanding the molecular function of PrP{sup C} in monocytes and macrophages.« less

Dexamethasone inhibits activation of monocytes/macrophages in a milieu rich in 27-oxygenated cholesterol.

PubMed

Kim, Bo-Young; Son, Yonghae; Lee, Jeonga; Choi, Jeongyoon; Kim, Chi Dae; Bae, Sun Sik; Eo, Seong-Kug; Kim, Koanhoi

2017-01-01

Molecular mechanisms underlying the decreased number of macrophages and T cells in the arteries of cholesterol-fed-rabbits following dexamethasone administration are unknown. We investigated the possibility that dexamethasone could affect activation of monocytic cells induced by oxygenated derivatives of cholesterol (oxysterols) using THP-1 monocyte/macrophage cells. 27-Hydroxycholesterol (27OHChol), an oxysterol elevated with hypercholesterolemia, enhanced production of CCL2, known as MCP1, chemokine from monocytes/macrophages and migration of the monocytic cells, but the CCL2 production and the cell migration were reduced by treatment with dexamethasone. Dexamethasone inhibited superproduction of CCL2 induced by 27OHChol plus LPS and attenuated transcription of matrix metalloproteinase 9 as well as secretion of its active gene product induced by 27OHChol. The drug downregulated cellular and surface levels of CD14 and blocked release of soluble CD14 without altering transcription of the gene. Dexamethasone also inhibited expression and phosphorylation of the NF-κB p65 subunit enhanced by 27OHChol. Collectively, these results indicate that dexamethasone inhibits activation of monocytes/macrophages in response to 27OHChol, thereby leading to decreased migration of inflammatory cells in milieu rich in oxygenated derivatives of cholesterol.

Dexamethasone inhibits activation of monocytes/macrophages in a milieu rich in 27-oxygenated cholesterol

PubMed Central

Kim, Bo-Young; Son, Yonghae; Lee, Jeonga; Choi, Jeongyoon; Kim, Chi Dae; Bae, Sun Sik; Eo, Seong-Kug

2017-01-01

Molecular mechanisms underlying the decreased number of macrophages and T cells in the arteries of cholesterol-fed-rabbits following dexamethasone administration are unknown. We investigated the possibility that dexamethasone could affect activation of monocytic cells induced by oxygenated derivatives of cholesterol (oxysterols) using THP-1 monocyte/macrophage cells. 27-Hydroxycholesterol (27OHChol), an oxysterol elevated with hypercholesterolemia, enhanced production of CCL2, known as MCP1, chemokine from monocytes/macrophages and migration of the monocytic cells, but the CCL2 production and the cell migration were reduced by treatment with dexamethasone. Dexamethasone inhibited superproduction of CCL2 induced by 27OHChol plus LPS and attenuated transcription of matrix metalloproteinase 9 as well as secretion of its active gene product induced by 27OHChol. The drug downregulated cellular and surface levels of CD14 and blocked release of soluble CD14 without altering transcription of the gene. Dexamethasone also inhibited expression and phosphorylation of the NF-κB p65 subunit enhanced by 27OHChol. Collectively, these results indicate that dexamethasone inhibits activation of monocytes/macrophages in response to 27OHChol, thereby leading to decreased migration of inflammatory cells in milieu rich in oxygenated derivatives of cholesterol. PMID:29236764

Chronic psoriatic skin inflammation leads to increased monocyte adhesion and aggregation

PubMed Central

Golden, Jackelyn B.; Groft, Sarah G.; Squeri, Michael V.; Debanne, Sara M.; Ward, Nicole L.; McCormick, Thomas S.; Cooper, Kevin D.

2015-01-01

Psoriasis patients exhibit an increased risk of death by cardiovascular disease (CVD) and have elevated levels of circulating intermediate (CD14++CD16+) monocytes. This elevation could represent evidence of monocyte dysfunction in psoriasis patients at risk of CVD, as increases in circulating CD14++CD16+ monocytes are predictive of myocardial infarction and death. An elevation in the CD14++CD16+ cell population has been previously reported in patients with psoriatic disease, which has been confirmed in the cohort of our human psoriasis patients. CD16 expression was induced in CD14++CD16neg classical monocytes following plastic adhesion, which also elicited enhanced β2 but not β1 integrin surface expression, suggesting increased adhesive capacity. Indeed, we found that psoriasis patients have increased monocyte aggregation among circulating PBMCs which is recapitulated in the KC-Tie2 murine model of psoriasis. Visualization of human monocyte aggregates using imaging cytometry revealed that classical CD14++CD16neg monocytes are the predominant cell type participating in these aggregate pairs. Many of these pairs also included CD16+ monocytes, which could account for apparent elevations of intermediate monocytes. Additionally, intermediate monocytes and monocyte aggregates were the predominant cell type to adhere to TNF-α and IL-17A-stimulated dermal endothelium. Ingenuity Pathway Analysis (IPA) demonstrated that monocyte aggregates have a distinct transcriptional profile from singlet monocytes and monocytes following plastic adhesion, suggesting that circulating monocyte responses to aggregation are not fully accounted for by homotypic adhesion, and that further factors influence their functionality. PMID:26223654

Association of Canine Osteosarcoma and Monocyte Phenotype and Chemotactic Function.

PubMed

Tuohy, J L; Lascelles, B D X; Griffith, E H; Fogle, J E

2016-07-01

Monocytes/macrophages are likely key cells in immune modulation in dogs with osteosarcoma (OSA). Increased peripheral monocyte counts are negatively correlated with shorter disease-free intervals in dogs with OSA. Understanding the monocyte/macrophage's modulatory role in dogs with OSA can direct further studies in immunotherapy development for OSA. That OSA evades the immune response by down-regulating monocyte chemokine receptor expression and migratory function, and suppresses host immune responses. Eighteen dogs with OSA that have not received definitive treatment and 14 healthy age-matched controls Clinical study-expression of peripheral blood monocyte cell surface receptors, monocyte mRNA expression and cytokine secretion, monocyte chemotaxis, and survival were compared between clinical dogs with OSA and healthy control dogs. Cell surface expression of multiple chemokine receptors is significantly down-regulated in peripheral blood monocytes of dogs with OSA. The percentage expression of CCR2 (median 58%, range 2-94%) and CXCR2 expression (median 54%, range 2-92%) was higher in control dogs compared to dogs with OSA (CCR2 median 29%, range 3-45%, P = 0.0006; CXCR2 median 23%, range 0.2-52%, P = 0.0007). Prostaglandin E2 (PGE2 ) (OSA, median 347.36 pg/mL, range 103.4-1268.5; control, 136.23 pg/mL, range 69.93-542.6, P = .04) and tumor necrosis factor-alpha (TNF-α) (P = .02) levels are increased in OSA monocyte culture supernatants compared to controls. Peripheral blood monocytes of dogs with OSA exhibit decreased chemotactic function when compared to control dogs (OSA, median 1.2 directed to random migration, range 0.8-1.25; control, 1.6, range of 0.9-1.8, P = .018). Dogs with OSA have decreased monocyte chemokine receptor expression and monocyte chemotaxis, potential mechanisms by which OSA might evade the immune response. Reversal of monocyte dysfunction using immunotherapy could improve survival in dogs with OSA. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Surface topography of hairy cell leukemia cells compared to other leukemias as seen by scanning electron microscopy.

PubMed

Polliack, Aaron; Tadmor, Tamar

2011-06-01

This short review deals with the ultrastructural surface architecture of hairy cell leukemia (HCL) compared to other leukemic cells, as seen by scanning electron microscopy (SEM). The development of improved techniques for preparing blood cells for SEM in the 1970s readily enabled these features to be visualized more accurately. This review returns us to the earlier history of SEM, when the surface topography of normal and neoplastic cells was visualized and reported for the first time, in an era before the emergence and use of monoclonal antibodies and flow cytometry, now used routinely to define cells by their immunophenotype. Surface microvilli are characteristic for normal and leukemic lymphoid cells, myelo-monocytic cells lack microvilli and show surface ruffles, while leukemic plasma and myeloma cells and megakaryocytes display large surface blebs. HCL cell surfaces are complex and typically 'hybrid' in nature, displaying both lymphoid and monocytic features with florid ruffles of varying sizes interspersed with clumps of short microvilli cytoplasm. The surface features of other leukemic cells and photomicrographs of immuno-SEM labeling of cells employing antibodies and colloidal gold, reported more than 20 years ago, are shown.

Tumour necrosis factor-alpha expression by activated monocytes and altered T-cell homeostasis in ascitic alcoholic cirrhosis: amelioration with norfloxacin.

PubMed

Albillos, Agustín; Hera Ad, Antonio de la; Reyes, Eduardo; Monserrat, Jorge; Muñoz, Leticia; Nieto, Mónica; Prieto, Alfredo; Sanz, Eva; Alvarez-Mon, Melchor

2004-04-01

To investigate the distribution and activation state of circulating monocytes and T-cell subsets, their contribution to tumour necrosis factor-alpha (TNFalpha) production, and their potential relationship with bacterial products of enteric origin in alcoholic cirrhosis. Peripheral blood monocytes and T-lymphocytes from 60 cirrhotic patients and 24 controls were characterized by four-color flow-cytometry after labelling of differentiation antigens and cytokines, before and after a 4-week course of norfloxacin or placebo. Monocytes from ascitic patients showed increased number, enhanced CD80 and HLA-DR surface levels, and spontaneous intracytoplasmic TNFalpha expression, when compared to non-ascitic patients and controls. Blood TNFalpha levels directly correlated with the amount of TNFalpha expressed by monocytes. In ascitic patients, there was a collapse of virgin CD4(+) and CD8(+) T-cell subsets; and, an expansion of activated CD4(+) T-cells. The above abnormalities were mainly restricted to ascitic patients with high serum levels of lypolysaccharide-binding-protein. Norfloxacin normalized the number of monocytes, reduced their activated phenotype and ability to produce TNFalpha and improved the abnormal T-cell homeostasis. In ascitic cirrhosis with high lipolysaccharide-binding-protein, monocytes are spontaneously activated to produce TNFalpha and are major contributors to the elevated serum TNFalpha. The T-cell compartment is profoundly depleted. Enteric bacterial products play a relevant role in these immune cellular abnormalities.

Chemical and physical effects on the adhesion, maturation, and survival of monocytes, macrophages, and foreign body giant cells

NASA Astrophysics Data System (ADS)

Collier, Terry Odell, III

Injury caused by biomedical device implantation initiates inflammatory and wound healing responses. Cells migrate to the site of injury to degrade bacteria and toxins, create new vasculature, and form new and repair injured tissue. Blood-proteins rapidly adsorb onto the implanted material surface and express adhesive ligands which mediate cell adhesion on the material surface. Monocyte-derived macrophages and multi-nucleated foreign body giant cells adhere to the surface and degrade the surface of the material. Due to the role of macrophage and foreign body giant cell on material biocompatibility and biostability, the effects of surface chemistry, surface topography and specific proteins on the maturation and survival of monocytes, macrophages and foreign body giant cells has been investigated. Novel molecularly designed materials were used to elucidate the dynamic interactions which occur between inflammatory cells, proteins and surfaces. The effect of protein and protein adhesion was investigated using adhesive protein depleted serum conditions on RGD-modified and silane modified surfaces. The effects of surface chemistry were investigated using temperature responsive surfaces of poly (N-isopropylacrylamide) and micropatterned surfaces of N-(2 aminoethyl)-3-aminopropyltrimethoxysilane regions on an interpenetrating polymer network of polyacrylamide and poly(ethylene glycol). The physical effects were investigated using polyimide scaffold materials and polyurethane materials with surface modifying end groups. The depletion of immunoglobulin G caused decreased levels of macrophage adhesion, foreign body giant cell formation and increased levels of apoptosis. The temporal nature of macrophage adhesion was observed with changing effectiveness of adherent cell detachment with time, which correlated to increased expression of beta1 integrin receptors on detached macrophages with time. The limited ability of the micropatterned surface, polyimide scaffold and surface modified polyurethane materials to control macrophage adhesion indicates the complexity of macrophage adhesion and protein adsorption onto a surface. These studies have indicated components and adhesive mechanisms which can be utilized to create materials with enhanced resistance to macrophage adhesion and/or degradative abilities.

A hormone map of human immune cells showing the presence of adrenocorticotropic hormone, triiodothyronine and endorphin in immunophenotyped white blood cells

PubMed Central

Pállinger, Éva; Csaba, György

2008-01-01

The amounts of adrenocorticotropic hormone (ACTH), endorphin and triiodothyronine (T3) in twenty-six blood samples from men and women who were healthy or had non-haematological diseases were determined by flow cytometry. Lymphocytes were immunophenotyped using monoclonal antibodies against cell surface antigens, and monocytes and granulocytes were separated by their size and granularity (using forward-scatter versus side-scatter dot plots). Each hormone was found in each cell type. The hormone content of lymphocytes was balanced, but the concentration of ACTH was significantly lower in activated T cells, that of endorphin was significantly lower in natural killer (NK) cells, and that of T3 was lower in both cell types compared with values for all lymphocytes. Monocytes and granulocytes contained very significantly more hormones than lymphocytes or monocytes. The concentration of endorphin was an order of magnitude higher in granulocytes than in monocytes or lymphocytes, reflecting the pain-relieving role of granulocytes during inflammation. Compared with monocytes, in granulocytes there was a higher concentration of ACTH and a lower concentration of T3, which suggests selective hormone production by these cells. PMID:18005034

Complement C3 participation in monocyte adhesion to different surfaces.

PubMed Central

McNally, A K; Anderson, J M

1994-01-01

As part of an ongoing investigation into the role of the monocyte/macrophage in biocompatibility, a major goal is to identify the adhesion mechanisms that initiate and promote the observed in vivo morphologic progression of monocyte-to-macrophage-to-foreign body giant cell on biomaterials. We have exploited differently modified polystyrenes, specific component-depleted sera, and monoclonal antibodies (mAbs) to leukocyte integrins to ask what adhesion mechanisms mediate human blood monocyte adhesion to different surfaces in vitro. Preliminary findings are that monocyte interactions with fluorinated, siliconized, nitrogenated, and oxygenated surfaces are reduced by 50-100% when complement component C3-depleted serum is used for adsorption; reductions vary with material surface properties. Adhesion is restored on all surfaces when C3-depleted serum is replenished with purified C3. Monocyte adhesion to serum-adsorbed surfaces is inhibited by mAbs to the leukocyte integrin beta subunit, CD18 (mAbs 60.3 and MHM23), and partially inhibited by a mAb to the alpha subunit, CD11b (mAb 60.1), suggesting adhesive interactions between adsorbed C3bi (the hemolytically inactive form of the C3b fragment) and the leukocyte integrin CD11b/CD18. However, adsorbed fibrinogen reduces the effectiveness of these mAbs, indicating that alternative adhesion mechanisms may operate depending on the propensities of critical adhesion-mediating components to be adsorbed onto different surfaces. Images PMID:7937848

Changes in Monocyte Functions of Astronauts

NASA Technical Reports Server (NTRS)

Kaur, I.; Simons, E.; Castro, V.; Ott, C. Mark; Pierson, Duane L.

2004-01-01

Monocyte cell numbers and functions, including phagocytosis, oxidative burst capacity, and degranulation and expression of related surface molecules, were studied in blood specimens from 25 astronauts and 9 healthy control subjects. Blood samples were obtained 10 days before a space flight, 3 hours after landing and 3 days after landing. The number of monocytes in astronauts did not change significantly among the three sample collection periods. Following space flight, the monocytes ability to phagocytize Escherichia coli, to exhibit an oxidative burst, and to degranulate was reduced as compared to monocytes from control subjects. These alterations in monocyte functions after space flight correlated with alterations in the expression of CD32 and CD64.

The continuum of monocyte phenotypes: Experimental evidence and prognostic utility in assessing cardiovascular risk.

PubMed

Cignarella, Andrea; Tedesco, Serena; Cappellari, Roberta; Fadini, Gian Paolo

2018-03-30

The monocyte-macrophage cell lineage represents a major player in innate immunity, and is involved in many physiologic and pathologic conditions. Particularly, monocyte-macrophages play a very important role in atherosclerosis and cardiovascular disease. Monocyte heterogeneity is well recognized but the biologic and clinical meaning of the various monocyte subtypes is not entirely understood. Traditionally, monocytes can be divided in classical, intermediate, and nonclassical based on expression of the surface antigens CD14 and CD16. While macrophage diversity is now well recognized to organize as a continuum, monocyte subsets have long been considered as separated entities. However, mounting evidence obtained by tracking the ontology of human monocytes help clarifying that monocytes mature from classical to nonclassical ones, through an intermediate phenotype. This concept is therefore best depicted as a continuum, whereas the subdivision into discrete CD14/CD16 subsets appears an oversimplification. In this review, we discuss the evidence supporting the existence of a monocyte continuum along with the technical challenges of monocyte characterization. In particular, we describe the advantage of considering monocytes along a continuous distribution for the evaluation of cardiovascular risk. We make the point that small transition along the monocyte continuum better reflects cardiovascular risk than a simplified analysis of discrete monocyte subsets. Recognizing the monocyte continuum can be helpful to model other pathophysiologic conditions where these cells are involved. ©2018 Society for Leukocyte Biology.

Increased adherence of sickled and phosphatidylserine-enriched human erythrocytes to cultured human peripheral blood monocytes.

PubMed

Schwartz, R S; Tanaka, Y; Fidler, I J; Chiu, D T; Lubin, B; Schroit, A J

1985-06-01

The precise mechanism by which sickle erythrocytes (RBC) are removed from the circulation is controversial, although it is possible that enhanced recognition of these cells by circulating mononuclear phagocytes could contribute to this process. We investigated this possibility by interacting sickle cells with cultured human peripheral blood monocytes. Our results show that both irreversibly sickled cells (ISC) and deoxygenated reversibly sickled cells (RSC) had a higher avidity for adherence to monocytes than did oxygenated sickle and normal RBC. ISC were the most adherent cell type. Adherence of RSC to monocytes was found to be reversible; reoxygenation of deoxygenated RSC resulted in a significant decrease in RSC--monocyte adherence. Concomitant with alterations in sickle RBC adherence were alterations in the organization and bilayer distribution of membrane phospholipids in these cells. Specifically, enhanced adherence was associated with increased exposure of RBC membrane outer leaflet phosphatidylserine (PS) and phosphatidylethanolamine, whereas lack of adherence was associated with normal patterns of membrane phospholipid distribution. To investigate the possibility of whether the exposure of PS in the outer membrane leaflet of these cells might be responsible for their recognition by monocytes, the membranes of normal RBC were enriched with the fluorescent PS analogue 1-acyl-2[(N-4-nitro-benzo-2-oxa-1,3-diazole)aminocaproyl]-phosphatidy lse rine (NBD-PS) via transfer of the exogenous lipid from a population of donor phospholipid vesicles (liposomes). RBC enriched with NBD-PS exhibited enhanced adherence to monocytes, whereas adherence of RBC enriched with similar amounts of NBD-phosphatidylcholine (NBD-PC) was not increased. Furthermore, preincubation of monocytes with PS liposomes resulted in a approximately 60% inhibition of ISC adherence to monocytes, whereas no inhibition occurred when monocytes were preincubated with PC liposomes. These findings strongly suggest that erythrocyte surface PS may be a ligand recognized by receptors on human peripheral blood monocytes and that abnormal exposure of PS in the outer leaflet of the RBC membrane, as found in sickle RBC, might serve to trigger their recognition by circulating monocytes. Our results further suggest that abnormalities in the organization of erythrocyte membrane phospholipids may have significant pathophysiologic implications, possibly including shortened cell survival.

Biomaterial adherent macrophage apoptosis is increased by hydrophilic and anionic substrates in vivo

NASA Astrophysics Data System (ADS)

Brodbeck, William G.; Patel, Jasmine; Voskerician, Gabriela; Christenson, Elizabeth; Shive, Matthew S.; Nakayama, Yasuhide; Matsuda, Takehisa; Ziats, Nicholas P.; Anderson, James M.

2002-08-01

An in vivo rat cage implant system was used to identify potential surface chemistries that prevent failure of implanted biomedical devices and prostheses by limiting monocyte adhesion and macrophage fusion into foreign-body giant cells while inducing adherent-macrophage apoptosis. Hydrophobic, hydrophilic, anionic, and cationic surfaces were used for implantation. Analysis of the exudate surrounding the materials revealed no differences between surfaces in the types or levels of cells present. Conversely, the proportion of adherent cells undergoing apoptosis was increased significantly on anionic and hydrophilic surfaces (46 ± 3.7 and 57 ± 5.0%, respectively) when compared with the polyethylene terephthalate base surface. Additionally, hydrophilic and anionic substrates provided decreased rates of monocyte/macrophage adhesion and fusion. These studies demonstrate that biomaterial-adherent cells undergo material-dependent apoptosis in vivo, rendering potentially harmful macrophages nonfunctional while the surrounding environment of the implant remains unaffected.

EMMPRIN (CD147/basigin) mediates platelet-monocyte interactions in vivo and augments monocyte recruitment to the vascular wall.

PubMed

Schulz, C; von Brühl, M-L; Barocke, V; Cullen, P; Mayer, K; Okrojek, R; Steinhart, A; Ahmad, Z; Kremmer, E; Nieswandt, B; Frampton, J; Massberg, S; Schmidt, R

2011-05-01

Platelets play a central role in hemostasis, in inflammatory diseases such as atherosclerosis, and during thrombus formation following vascular injury. Thereby, platelets interact intensively with monocytes and enhance their recruitment to the vascular wall. To investigate the role of the extracellular matrix metalloproteinase inducer (EMMPRIN) in platelet-monocyte interactions. Isolated human monocytes were perfused in vitro over firmly adherent platelets to allow investigation of the role of EMMPRIN in platelet-monocyte interactions under flow conditions. Monocytes readily bound to surface-adherent platelets. Both antibody blockade and gene silencing of monocyte EMMPRIN substantially attenuated firm adhesion of monocytes to platelets at arterial and venous shear rates. In vivo, platelet interactions with the murine monocyte cell line ANA-1 were significantly decreased when ANA-1 cells were pretreated with EMMPRIN-silencing small interfering RNA prior to injection into wild-type mice. Using intravital microscopy, we showed that recruitment of EMMPRIN-silenced ANA-1 to the injured carotid artery was significantly reduced as compared with control cells. Further silencing of EMMPRIN resulted in significantly fewer ANA-1-platelet aggregates in the mouse circulation as determined by flow cytometry. Finally, we identified glycoprotein (GP)VI as a critical corresponding receptor on platelets that mediates interaction with monocyte EMMPRIN. Thus, blocking of GPVI inhibited the effect of EMMPRIN on firm monocyte adhesion to platelets under arterial flow conditions in vitro, and abrogated EMMPRIN-mediated platelet-monocyte aggregate formation in vivo. EMMPRIN supports platelet-monocyte interactions and promotes monocyte recruitment to the arterial wall. Therefore, EMMPRIN might represent a novel target to reduce vascular inflammation and atherosclerotic lesion development. © 2011 International Society on Thrombosis and Haemostasis.

Inhibition of the Differentiation of Monocyte-Derived Dendritic Cells by Human Gingival Fibroblasts

PubMed Central

Séguier, Sylvie; Tartour, Eric; Guérin, Coralie; Couty, Ludovic; Lemitre, Mathilde; Lallement, Laetitia; Folliguet, Marysette; Naderi, Samah El; Terme, Magali; Badoual, Cécile; Lafont, Antoine; Coulomb, Bernard

2013-01-01

We investigated whether gingival fibroblasts (GFs) can modulate the differentiation and/or maturation of monocyte-derived dendritic cells (DCs) and analyzed soluble factors that may be involved in this immune modulation. Experiments were performed using human monocytes in co-culture with human GFs in Transwell® chambers or using monocyte cultures treated with conditioned media (CM) from GFs of four donors. The four CM and supernatants from cell culture were assayed by ELISA for cytokines involved in the differentiation of dendritic cells, such as IL-6, VEGF, TGFβ1, IL-13 and IL-10. The maturation of monocyte-derived DCs induced by LPS in presence of CM was also studied. Cell surface phenotype markers were analyzed by flow cytometry. In co-cultures, GFs inhibited the differentiation of monocyte-derived DCs and the strength of this blockade correlated with the GF/monocyte ratio. Conditioned media from GFs showed similar effects, suggesting the involvement of soluble factors produced by GFs. This inhibition was associated with a lower stimulatory activity in MLR of DCs generated with GFs or its CM. Neutralizing antibodies against IL-6 and VEGF significantly (P<0.05) inhibited the inhibitory effect of CM on the differentiation of monocytes-derived DCs and in a dose dependent manner. Our data suggest that IL-6 is the main factor responsible for the inhibition of DCs differentiation mediated by GFs but that VEGF is also involved and constitutes an additional mechanism. PMID:23936476

Heterogeneity of clonogenic cells in acute myeloblastic leukemia.

PubMed Central

Sabbath, K D; Ball, E D; Larcom, P; Davis, R B; Griffin, J D

1985-01-01

The expression of differentiation-associated surface antigens by the clonogenic leukemic cells from 20 patients with acute myeloblastic leukemia (AML) was studied with a panel of seven cytotoxic monoclonal antibodies (anti-Ia, -MY9, -PM-81, -AML-2-23, -Mol, -Mo2, and -MY3). The surface antigen phenotypes of the clonogenic cells were compared with the phenotypes of the whole leukemic cell population, and with the phenotypes of normal hematopoietic progenitor cells. In each case the clonogenic leukemic cells were found within a distinct subpopulation that was less "differentiated" than the total cell population. Clonogenic leukemic cells from different patients could be divided into three phenotype groups. In the first group (7 of 20 cases), the clonogenic cells expressed surface antigens characteristic of the normal multipotent colony-forming cell (Ia, MY9). These cases tended to have "undifferentiated" (FAB M1) morphology, and the total cell population generally lacked expression of "late" monocyte antigens such as MY3 and Mo2. A second group (seven cases) of clonogenic cells expressed surface antigens characteristic of an "early" (day 14) colony-forming unit granulocyte-monocyte (CFU-GM), and a third group (six cases) was characteristic of a "late" (day 7) CFU-GM. The cases in these latter two groups tended to have myelomonocytic (FAB M4) morphology and to express monocyte surface antigens. These results suggest that the clonogenic cells are a distinct subpopulation in all cases of AML, and may be derived from normal hematopoietic progenitor cells at multiple points in the differentiation pathway. The results further support the possibility that selected monoclonal antibodies have the potential to purge leukemic clonogenic cells from bone marrow in some AML patients without eliminating critical normal progenitor cells. PMID:3855866

Heterogeneity of clonogenic cells in acute myeloblastic leukemia.

PubMed

Sabbath, K D; Ball, E D; Larcom, P; Davis, R B; Griffin, J D

1985-02-01

The expression of differentiation-associated surface antigens by the clonogenic leukemic cells from 20 patients with acute myeloblastic leukemia (AML) was studied with a panel of seven cytotoxic monoclonal antibodies (anti-Ia, -MY9, -PM-81, -AML-2-23, -Mol, -Mo2, and -MY3). The surface antigen phenotypes of the clonogenic cells were compared with the phenotypes of the whole leukemic cell population, and with the phenotypes of normal hematopoietic progenitor cells. In each case the clonogenic leukemic cells were found within a distinct subpopulation that was less "differentiated" than the total cell population. Clonogenic leukemic cells from different patients could be divided into three phenotype groups. In the first group (7 of 20 cases), the clonogenic cells expressed surface antigens characteristic of the normal multipotent colony-forming cell (Ia, MY9). These cases tended to have "undifferentiated" (FAB M1) morphology, and the total cell population generally lacked expression of "late" monocyte antigens such as MY3 and Mo2. A second group (seven cases) of clonogenic cells expressed surface antigens characteristic of an "early" (day 14) colony-forming unit granulocyte-monocyte (CFU-GM), and a third group (six cases) was characteristic of a "late" (day 7) CFU-GM. The cases in these latter two groups tended to have myelomonocytic (FAB M4) morphology and to express monocyte surface antigens. These results suggest that the clonogenic cells are a distinct subpopulation in all cases of AML, and may be derived from normal hematopoietic progenitor cells at multiple points in the differentiation pathway. The results further support the possibility that selected monoclonal antibodies have the potential to purge leukemic clonogenic cells from bone marrow in some AML patients without eliminating critical normal progenitor cells.

Extracellular calcium elicits a chemokinetic response from monocytes in vitro and in vivo

NASA Technical Reports Server (NTRS)

Olszak, I. T.; Poznansky, M. C.; Evans, R. H.; Olson, D.; Kos, C.; Pollak, M. R.; Brown, E. M.; Scadden, D. T.; O'Malley, B. W. (Principal Investigator)

2000-01-01

Recruitment of macrophages to sites of cell death is critical for induction of an immunologic response. Calcium concentrations in extracellular fluids vary markedly, and are particularly high at sites of injury or infection. We hypothesized that extracellular calcium participates in modulating the immune response, perhaps acting via the seven-transmembrane calcium-sensing receptor (CaR) on mature monocytes/macrophages. We observed a dose-dependent increase in monocyte chemotaxis in response to extracellular calcium or the selective allosteric CaR activator NPS R-467. In contrast, monocytes derived from mice deficient in CaR lacked the normal chemotactic response to a calcium gradient. Notably, CaR activation of monocytes bearing the receptor synergistically augmented the transmigration response of monocytes to the chemokine MCP-1 in association with increased cell-surface expression of its cognate receptor, CCR2. Conversely, stimulation of monocytes with MCP-1 or SDF-1alpha reciprocally increased CaR expression, suggesting a dual-enhancing interaction of Ca(2+) with chemokines in recruiting inflammatory cells. Subcutaneous administration in mice of Ca(2+), MCP-1, or (more potently) the combination of Ca(2+) and MCP-1, elicited an inflammatory infiltrate consisting of monocytes/macrophages. Thus extracellular calcium functions as an ionic chemokinetic agent capable of modulating the innate immune response in vivo and in vitro by direct and indirect actions on monocytic cells. Calcium deposition may be both consequence and cause of chronic inflammatory changes at sites of injury, infection, and atherosclerosis.

Similarities and differences between helminth parasites and cancer cell lines in shaping human monocytes: Insights into parallel mechanisms of immune evasion.

PubMed

Narasimhan, Prakash Babu; Akabas, Leor; Tariq, Sameha; Huda, Naureen; Bennuru, Sasisekhar; Sabzevari, Helen; Hofmeister, Robert; Nutman, Thomas B; Tolouei Semnani, Roshanak

2018-04-01

A number of features at the host-parasite interface are reminiscent of those that are also observed at the host-tumor interface. Both cancer cells and parasites establish a tissue microenvironment that allows for immune evasion and may reflect functional alterations of various innate cells. Here, we investigated how the phenotype and function of human monocytes is altered by exposure to cancer cell lines and if these functional and phenotypic alterations parallel those induced by exposure to helminth parasites. Thus, human monocytes were exposed to three different cancer cell lines (breast, ovarian, or glioblastoma) or to live microfilariae (mf) of Brugia malayi-a causative agent of lymphatic filariasis. After 2 days of co-culture, monocytes exposed to cancer cell lines showed markedly upregulated expression of M1-associated (TNF-α, IL-1β), M2-associated (CCL13, CD206), Mreg-associated (IL-10, TGF-β), and angiogenesis associated (MMP9, VEGF) genes. Similar to cancer cell lines, but less dramatically, mf altered the mRNA expression of IL-1β, CCL13, TGM2 and MMP9. When surface expression of the inhibitory ligands PDL1 and PDL2 was assessed, monocytes exposed to both cancer cell lines and to live mf significantly upregulated PDL1 and PDL2 expression. In contrast to exposure to mf, exposure to cancer cell lines increased the phagocytic ability of monocytes and reduced their ability to induce T cell proliferation and to expand Granzyme A+ CD8+ T cells. Our data suggest that despite the fact that helminth parasites and cancer cell lines are extraordinarily disparate, they share the ability to alter the phenotype of human monocytes.

Antiretroviral therapy in HIV-1-infected individuals with CD4 count below 100 cells/mm3 results in differential recovery of monocyte activation

PubMed Central

Patro, Sean C.; Azzoni, Livio; Joseph, Jocelin; Fair, Matthew G.; Sierra-Madero, Juan G.; Rassool, Mohammed S.; Sanne, Ian; Montaner, Luis J.

2016-01-01

Reversal of monocyte and macrophage activation and the relationship to viral suppression and T cell activation are unknown in patients with advanced HIV-1 infection, initiating antiretroviral therapy. This study aimed to determine whether reduction in biomarkers of monocyte and macrophage activation would be reduced in conjunction with viral suppression and resolution of T cell activation. Furthermore, we hypothesized that the addition of CCR5 antagonism (by maraviroc) would mediate greater reduction of monocyte/macrophage activation markers than suppressive antiretroviral therapy alone. In the CCR5 antagonism to decrease the incidence of immune reconstitution inflammatory syndrome study, antiretroviral therapy-naïve patients received maraviroc or placebo in addition to standard antiretroviral therapy. PBMCs and plasma from 65 patients were assessed during 24 wk of antiretroviral therapy for biomarkers of monocyte and macrophage activation. Markers of monocyte and macrophage activation were reduced significantly by 24 wk, including CD14++CD16+ intermediate monocytes (P < 0.0001), surface CD163 (P = 0.0004), CD169 (P < 0.0001), tetherin (P = 0.0153), and soluble CD163 (P < 0.0001). A change in CD38+, HLA-DR+ CD8 T cells was associated with changes in CD169 and tetherin expression. Maraviroc did not affect biomarkers of monocyte/macrophage activation but resulted in greater percentages of CCR5-positive monocytes in PBMC. HIV-1 suppression after 24 wk of antiretroviral therapy, with or without maraviroc, demonstrates robust recovery in monocyte subset activation markers, whereas soluble markers of activation demonstrate minimal decrease, qualitatively differentiating markers of monocyte/macrophage activation in advanced disease. PMID:26609048

In vitro uptake of apoptotic body mimicking phosphatidylserine-quantum dot micelles by monocytic cell line

NASA Astrophysics Data System (ADS)

Maiseyeu, Andrei; Bagalkot, Vaishali

2014-04-01

A new quantum dot (QD) PEGylated micelle laced with phosphatidylserine (PS) for specific scavenger receptor-mediated uptake by macrophages is reported. The size and surface chemistry of PS-QD micelles were characterized by standard methods and the effects of their physicochemical properties on specific targeting and uptake were comprehensively studied in a monocytic cell line (J774A.1).

Evidence for a link between sphingolipid metabolism and expression of CD1d and MHC-class II: monocytes from Gaucher disease patients as a model.

PubMed

Balreira, Andrea; Lacerda, Lúcia; Miranda, Clara Sá; Arosa, Fernando A

2005-06-01

Gaucher disease (GD) is an autosomal recessive inherited defect of the lysosomal enzyme glucocerebrosidase (GluCerase) that leads to glucosylceramide (GluCer) accumulation. We previously demonstrated the existence of imbalances in certain lymphocyte populations in GD patients. We now show that GluCerase-deficient monocytes from GD patients or monocytes from healthy subjects treated with conduritol-B-epoxide (CBE), an irreversible inhibitor of GluCerase activity, display high levels of surface expression of the lipid-binding molecule CD1d. GluCerase-deficient monocytes from GD patients also showed increased surface expression of major histocompatibility complex (MHC)-class II, but not of other lysosomal trafficking molecules, such as CD63 and MHC-class I. However, CD1d and MHC-class II mRNA levels were not increased. GluCerase-deficient monocytes from GD patients undergoing enzyme replacement therapy also exhibited increased levels of CD1d and MHC-class II and imbalances in the percentage of CD4+, CD8+, and Valpha24+ T cells. Interestingly, follow-up studies revealed that enzyme replacement therapy induced a decrease in MHC-class II expression and partial correction of the CD4+ T cell imbalances. These results reveal a new link between sphingolipid accumulation in monocytes and the expression of certain MHC molecules that may result in imbalances of regulatory T cell subsets. These immunological anomalies may contribute to the clinical heterogeneity in GD patients.

Adhesion kinetics of human primary monocytes, dendritic cells, and macrophages: Dynamic cell adhesion measurements with a label-free optical biosensor and their comparison with end-point assays.

PubMed

Orgovan, Norbert; Ungai-Salánki, Rita; Lukácsi, Szilvia; Sándor, Noémi; Bajtay, Zsuzsa; Erdei, Anna; Szabó, Bálint; Horvath, Robert

2016-09-01

Monocytes, dendritic cells (DCs), and macrophages (MFs) are closely related immune cells that differ in their main functions. These specific functions are, to a considerable degree, determined by the differences in the adhesion behavior of the cells. To study the inherently and essentially dynamic aspects of the adhesion of monocytes, DCs, and MFs, dynamic cell adhesion assays were performed with a high-throughput label-free optical biosensor [Epic BenchTop (BT)] on surfaces coated with either fibrinogen (Fgn) or the biomimetic copolymer PLL-g-PEG-RGD. Cell adhesion profiles typically reached their maximum at ∼60 min after cell seeding, which was followed by a monotonic signal decrease, indicating gradually weakening cell adhesion. According to the biosensor response, cell types could be ordered by increasing adherence as monocytes, MFs, and DCs. Notably, all three cell types induced a larger biosensor signal on Fgn than on PLL-g-PEG-RGD. To interpret this result, the molecular layers were characterized by further exploiting the potentials of the biosensor: by measuring the adsorption signal induced during the surface coating procedure, the authors could estimate the surface density of adsorbed molecules and, thus, the number of binding sites potentially presented for the adhesion receptors. Surfaces coated with PLL-g-PEG-RGD presented less RGD sites, but was less efficient in promoting cell spreading than those coated with Fgn; hence, other binding sites in Fgn played a more decisive role in determining cell adherence. To support the cell adhesion data obtained with the biosensor, cell adherence on Fgn-coated surfaces 30-60 min after cell seeding was measured with three complementary techniques, i.e., with (1) a fluorescence-based classical adherence assay, (2) a shear flow chamber applying hydrodynamic shear stress to wash cells away, and (3) an automated micropipette using vacuum-generated fluid flow to lift cells up. These techniques confirmed the results obtained with the high-temporal-resolution Epic BT, but could only provide end-point data. In contrast, complex, nonmonotonic cell adhesion kinetics measured by the high-throughput optical biosensor is expected to open a window on the hidden background of the immune cell-extracellular matrix interactions.

Degraded carrageenan causing colitis in rats induces TNF secretion and ICAM-1 upregulation in monocytes through NF-kappaB activation.

PubMed

Benard, Claudine; Cultrone, Antonietta; Michel, Catherine; Rosales, Carlos; Segain, Jean-Pierre; Lahaye, Marc; Galmiche, Jean-Paul; Cherbut, Christine; Blottière, Hervé M

2010-01-13

Carrageenan (CGN) is a high molecular weight sulphated polysaccharide derived from red seaweeds. In rodents, its degraded forms (dCGN) can induce intestinal inflammation associated with macrophage recruitment and activation. The aim of this study was: 1) to analyze the size-dependent effects of dCGN on colon inflammation in vivo, and 2) to correlate these effects with monocyte/macrophage proliferation, cytokine production and expression of various cell surface antigens including ICAM-1 adhesion molecule. Peripheral blood monocytes (PBM) and THP-1 monocytic cells were cultured in the presence of either 10 or 40 kDa, dCGN. The 40 kDa, but not the 10 kDa dCGN, induced colitis in in vivo. Degraded CGN inhibited THP-1 cell proliferation in vitro, arresting the cells in G1 phase. In addition, dCGN increased ICAM-1 expression in both PBM and THP-1 cells with a major effect seen after 40 kDa dCGN exposure. Also, dCGN stimulated monocyte aggregation in vitro that was prevented by incubation with anti-ICAM-1 antibody. Finally, dCGN stimulated TNF-alpha expression and secretion by both PBM and THP-1 cells. All these effects were linked to NF-kappaB activation. These data strongly suggest that the degraded forms of CGN have a pronounced effect on monocytes, characteristic of an inflammatory phenotype.

Ephrin-A1/EphA4-mediated adhesion of monocytes to endothelial cells.

PubMed

Jellinghaus, Stefanie; Poitz, David M; Ende, Georg; Augstein, Antje; Weinert, Sönke; Stütz, Beryl; Braun-Dullaeus, Rüdiger C; Pasquale, Elena B; Strasser, Ruth H

2013-10-01

The Eph receptors represent the largest family of receptor tyrosine kinases. Both Eph receptors and their ephrin ligands are cell-surface proteins, and they typically mediate cell-to-cell communication by interacting at sites of intercellular contact. The major aim of the present study was to investigate the involvement of EphA4-ephrin-A1 interaction in monocyte adhesion to endothelial cells, as this process is a crucial step during the initiation and progression of the atherosclerotic plaque. Immunohistochemical analysis of human atherosclerotic plaques revealed expression of EphA4 receptor and ephrin-A1 ligand in major cell types within the plaque. Short-time stimulation of endothelial cells with the soluble ligand ephrin-A1 leads to a fourfold increase in adhesion of human monocytes to endothelial cells. In addition, ephrin-A1 further increases monocyte adhesion to already inflamed endothelial cells. EphrinA1 mediates its effect on monocyte adhesion via the activated receptor EphA4. This ephrinA1/EphA4 induced process involves the activation of the Rho signaling pathway and does not require active transcription. Rho activation downstream of EphA4 leads to increased polymerization of actin filaments in endothelial cells. This process was shown to be crucial for the proadhesive effect of ephrin-A1. The results of the present study show that ephrin-A1-induced EphA4 forward signaling promotes monocyte adhesion to endothelial cells via activation of RhoA and subsequent stress-fiber formation by a non-transcriptional mechanism. Copyright © 2013 Elsevier B.V. All rights reserved.

Mono vs multilayer fibronectin coatings on polar/hydrophobic/ionic polyurethanes: Altering surface interactions with human monocytes.

PubMed

Gossart, Audrey; Battiston, Kyle G; Gand, Adeline; Pauthe, Emmanuel; Santerre, J Paul

2018-01-15

Monocyte interactions with materials that are biofunctionalized with fibronectin (Fn) are of interest because of the documented literature which associates this protein with white blood cell function at implant sites. A degradable-polar hydrophobic ionic polyurethane (D-PHI), has been reported to promote an anti-inflammatory response from human monocytes. The aim of the current work was to study the influence of intrinsic D-PHI material chemistry on Fn adsorption (mono and multi-layer structures), and to investigate the influence of such chemistry on the structural state of the Fn, as well as the latter's influence on the activity of human monocytes on the protein coated substrates. Significant differences in Fn adsorption, surface hydrophobicity and the availability of defined peptide sequences (N terminal, C terminal or Cell Binding Domain) for the Fn in mono vs multilayer structures were observed as a function of the changes in intrinsic material chemistry. A D-PHI-formulated polyurethane substrate with subtle changes in anionic and hydrophobic domain content relative to the polar non-ionic urethane/carbonate groups within the polymer matrix promoted the lowest activation of monocytes, in the presence of multi-layer Fn constructs. These results highlight the importance of chemical heterogeneity as a design parameter for biomaterial surfaces, and establishes a desired strategy for controlling human monocyte activity at the surface of devices, when these are coated with multi-layer Fn structures. The latter is an important step towards functionalizing the materials with multi-layer protein drug carriers as interventional therapeutic agents. The control of the behavior of monocytes, especially migration and activation, is of crucial interest to modulate the inflammatory response at the site of implanted biomaterial. Several studies report the influence of adsorbed serum proteins on the behavior of monocytes on biomaterials. However, few studies show the influence of surface chemical group distribution on the controlled adsorption and the subsequent induced conformation- of mono versus multi-layer assembled structures generated from specific proteins implicated in wound repair. The current research considered the role of Fn adsorption and conformation in thin films while interacting with the intrinsic chemistry of segmented block polyurethanes; and the influence of the former on modulation and activation of human monocytes. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Identification of a Monocyte Receptor on Herpesvirus-Infected Endothelial Cells

NASA Astrophysics Data System (ADS)

Etingin, Orli R.; Silverstein, Roy L.; Hajjar, David P.

1991-08-01

The adhesion of circulating blood cells to vascular endothelium may be an initial step in atherosclerosis, inflammation, and wound healing. One mechanism for promoting cell-cell adhesion involves the expression of adhesion molecules on the surface of the target cell. Herpes simplex virus infection of endothelium induces arterial injury and has been implicated in the development of human atherosclerosis. We now demonstrate that HSV-infected endothelial cells express the adhesion molecule GMP140 and that this requires cell surface expression of HSV glycoprotein C and local thrombin generation. Monocyte adhesion to HSV-infected endothelial cells was completely inhibited by anti-GMP140 antibodies but not by antibodies to other adhesion molecules such as VCAM and ELAM-1. The induction of GMP140 expression on HSV-infected endothelium may be an important pathophysiological mechanism in virus-induced cell injury and inflammation.

Decreased Superoxide Production, Degranulation, Tumor Necrosis Factor Alpha Secretion, and CD11b/CD18 Receptor Expression by Adherent Monocytes from Preterm Infants

PubMed Central

Kaufman, David; Kilpatrick, Laurie; Hudson, R. Guy; Campbell, Donald E.; Kaufman, Ann; Douglas, Steven D.; Harris, Mary C.

1999-01-01

Preterm infants have an increased incidence of infection, which is principally due to deficiencies in neonatal host defense mechanisms. Monocyte adherence is important in localizing cells at sites of infection and is associated with enhanced antimicrobial functions. We isolated cord blood monocytes from preterm and full-term infants to study their adhesion and immune functions, including superoxide (O2−) generation, degranulation, and cytokine secretion and their adhesion receptors. O2− production and degranulation were significantly diminished, by 28 and 37%, respectively, in adherent monocytes from preterm infants compared to full-term infants (P < 0.05); however, these differences were not seen in freshly isolated cells. We also observed a significant decrease of 35% in tumor necrosis factor alpha secretion by lipopolysaccharide-stimulated adherent monocytes from preterm infants compared to full-term infants (P < 0.05); however, this difference was not observed in interleukin-1β or interleukin-6 production by the monocytes. The cell surface expression of the CD11b/CD18 adhesion receptor subunits was significantly decreased (by 60 and 52%, respectively) in monocytes from preterm infants compared to full-term infants (P < 0.01). The cascade of the immune response to infection involves monocyte upregulation and adherence via CD11b/CD18 receptors followed by cell activation and the release of cytokines and bactericidal products. We speculate that monocyte adherence factors may be important in the modulation of immune responses in preterm infants. PMID:10391855

Methylglyoxal-bis-guanylhydrazone inhibits osteopontin expression and differentiation in cultured human monocytes.

PubMed

Jin, Xia; Xu, Hua; McGrath, Michael S

2018-01-01

Monocyte activation and polarization play essential roles in many chronic inflammatory diseases. An imbalance of M1 and M2 macrophage activation (pro-inflammatory and alternatively activated, respectively) is believed to be a key aspect in the etiology of these diseases, thus a therapeutic approach that regulates macrophage activation could be of broad clinical relevance. Methylglyoxal-bis-guanylhydrazone (MGBG), a regulator of polyamine metabolism, has recently been shown to be concentrated in monocytes and macrophages, and interfere with HIV integration into the DNA of these cells in vitro. RNA expression analysis of monocytes from HIV+ and control donors with or without MGBG treatment revealed the only gene to be consistently down regulated by MGBG to be osteopontin (OPN). The elevated expression of this pro-inflammatory cytokine and monocyte chemoattractant is associated with various chronic inflammatory diseases. We demonstrate that MGBG is a potent inhibitor of secreted OPN (sOPN) in cultured monocytes with 50% inhibition achieved at 0.1 μM of the drug. Furthermore, inhibition of OPN RNA transcription in monocyte cultures occurs at similar concentrations of the drug. During differentiation of monocytes into macrophages in vitro, monocytes express cell surface CD16 and the cells undergo limited DNA synthesis as measured by uptake of BrdU. MGBG inhibited both activities at similar doses to those regulating OPN expression. In addition, monocyte treatment with MGBG inhibited differentiation into both M1 and M2 classes of macrophages at non-toxic doses. The inhibition of differentiation and anti-OPN effects of MGBG were specific for monocytes in that differentiated macrophages were nearly resistant to MGBG activities. Thus MGBG may have potential therapeutic utility in reducing or normalizing OPN levels and regulating monocyte activation in diseases that involve chronic inflammation.

Distinct abnormalities in the innate immune system of children with Down syndrome.

PubMed

Bloemers, Beatrijs L P; van Bleek, Grada M; Kimpen, Jan L L; Bont, Louis

2010-05-01

To analyze the frequency and phenotype of cells of the innate immune system in the peripheral blood of children with Down syndrome (DS). Flow cytometric analysis of expression of cell surface markers was performed in children with DS (n = 41) and healthy age-matched controls (n = 41). Compared with controls, children with DS had significantly lower absolute total leukocyte counts, lymphocytes, monocytes, and granulocytes, but 1.5-times higher absolute numbers of CD14(dim)CD16(+) monocytes (147 x 10(6)/L vs 93 x 10(6)/L; P = .02). This difference is fully explained by a higher percentage of CD14(dim)CD16(+) monocytes within the monocyte compartment (28.7% vs 13.4%; P <.001). The absolute numbers of myeloid dendritic cells were lower in DS (13.8 x 10(6)/L vs 22.7 x 10(6)/L; P <.001). The numbers of plasmacytoid dendritic cells and natural killer cells were normal. Absolute numbers of invariant natural killer T cells were very low overall, but significantly lower in children with DS than in controls (1.2 x 10(6)/L vs 3.7 x 10(6)/L; P = .01). Children with DS exhibited distinct abnormalities in cells of the innate immune system. Most strikingly, they had a high number of proinflammatory CD14(dim)CD16(+) monocytes. This elevated level of CD14(dim)CD16(+) monocytes may play an important role in the onset and maintenance of chronic inflammatory disease in DS.

Activated Monocytes Enhance Platelet-Driven Contraction of Blood Clots via Tissue Factor Expression.

PubMed

Peshkova, Alina D; Le Minh, Giang; Tutwiler, Valerie; Andrianova, Izabella A; Weisel, John W; Litvinov, Rustem I

2017-07-11

Platelet-driven reduction in blood clot volume (clot contraction or retraction) has been implicated to play a role in hemostasis and thrombosis. Although these processes are often linked with inflammation, the role of inflammatory cells in contraction of blood clots and thrombi has not been investigated. The aim of this work was to study the influence of activated monocytes on clot contraction. The effects of monocytes were evaluated using a quantitative optical tracking methodology to follow volume changes in a blood clot formed in vitro. When a physiologically relevant number of isolated human monocytes pre-activated with phorbol-12-myristate-13-acetate (PMA) were added back into whole blood, the extent and rate of clot contraction were increased compared to addition of non-activated cells. Inhibition of tissue factor expression or its inactivation on the surface of PMA-treated monocytes reduced the extent and rate of clot contraction back to control levels with non-activated monocytes. On the contrary, addition of tissue factor enhanced clot contraction, mimicking the effects of tissue factor expressed on the activated monocytes. These data suggest that the inflammatory cells through their expression of tissue factor can directly affect hemostasis and thrombosis by modulating the size and density of intra- and extravascular clots and thrombi.

Human mesenchymal stromal cell-secreted lactate induces M2-macrophage differentiation by metabolic reprogramming

PubMed Central

Civini, Sara; Pacelli, Consiglia; Dieng, Mame Massar; Lemieux, William; Jin, Ping; Bazin, Renée; Patey, Natacha; Marincola, Francesco M.; Moldovan, Florina; Zaouter, Charlotte; Trudeau, Louis-Eric; Benabdhalla, Basma; Louis, Isabelle; Beauséjour, Christian; Stroncek, David; Le Deist, Françoise; Haddad, Elie

2016-01-01

Human mesenchymal stromal cells (MSC) have been shown to dampen immune response and promote tissue repair, but the underlying mechanisms are still under investigation. Herein, we demonstrate that umbilical cord-derived MSC (UC-MSC) alter the phenotype and function of monocyte-derived dendritic cells (DC) through lactate-mediated metabolic reprogramming. UC-MSC can secrete large quantities of lactate and, when present during monocyte-to-DC differentiation, induce instead the acquisition of M2-macrophage features in terms of morphology, surface markers, migratory properties and antigen presentation capacity. Microarray expression profiling indicates that UC-MSC modify the expression of metabolic-related genes and induce a M2-macrophage expression signature. Importantly, monocyte-derived DC obtained in presence of UC-MSC, polarize naïve allogeneic CD4+ T-cells into Th2 cells. Treatment of UC-MSC with an inhibitor of lactate dehydrogenase strongly decreases lactate concentration in culture supernatant and abrogates the effect on monocyte-to-DC differentiation. Metabolic analysis further revealed that UC-MSC decrease oxidative phosphorylation in differentiating monocytes while strongly increasing the spare respiratory capacity proportional to the amount of secreted lactate. Because both MSC and monocytes are recruited in vivo at the site of tissue damage and inflammation, we propose the local increase of lactate concentration induced by UC-MSC and the consequent enrichment in M2-macrophage generation as a mechanism to achieve immunomodulation. PMID:27070086

CXCL4/Platelet Factor 4 is an agonist of CCR1 and drives human monocyte migration.

PubMed

Fox, James M; Kausar, Fahima; Day, Amy; Osborne, Michael; Hussain, Khansa; Mueller, Anja; Lin, Jessica; Tsuchiya, Tomoko; Kanegasaki, Shiro; Pease, James E

2018-06-21

Activated platelets release micromolar concentrations of the chemokine CXCL4/Platelet Factor-4. Deposition of CXCL4 onto the vascular endothelium is involved in atherosclerosis, facilitating monocyte arrest and recruitment by an as yet, unidentified receptor. Here, we demonstrate that CXCL4 drives chemotaxis of the monocytic cell line THP-1. Migration and intracellular calcium responses induced by CXCL4 were pertussis toxin-sensitive, implicating a GPCR in signal transduction. Cell treatment with chondroitinase ABC ablated migration, suggesting that cis presentation of CXCL4 by cell surface glycosaminoglycans to a GPCR is required. Although CXCR3 has been previously described as a CXCL4 receptor, THP-1 cells were unresponsive to CXCR3 ligands and CXCL4-induced migration was insensitive to a CXCR3 antagonist, suggesting that an alternative receptor is involved. Interrogating CC-class chemokine receptor transfectants, we unexpectedly found that CXCL4 could induce the migration of CCR1-expressing cells and also induce CCR1 endocytosis. Extending our findings to primary human monocytes, we observed that CXCL4 induced CCR1 endocytosis and could induce monocyte chemotaxis in a CCR1 antagonist-sensitive manner. Collectively, our data identify CCR1 as a previously elusive monocyte CXCL4 receptor and suggest that CCR1 may play a role in inflammation where the release of CXCL4 is implicated.

Glia Maturation Factor-γ Regulates Monocyte Migration through Modulation of β1-Integrin*

PubMed Central

Aerbajinai, Wulin; Liu, Lunhua; Zhu, Jianqiong; Kumkhaek, Chutima; Chin, Kyung; Rodgers, Griffin P.

2016-01-01

Monocyte migration requires the dynamic redistribution of integrins through a regulated endo-exocytosis cycle, but the complex molecular mechanisms underlying this process have not been fully elucidated. Glia maturation factor-γ (GMFG), a novel regulator of the Arp2/3 complex, has been shown to regulate directional migration of neutrophils and T-lymphocytes. In this study, we explored the important role of GMFG in monocyte chemotaxis, adhesion, and β1-integrin turnover. We found that knockdown of GMFG in monocytes resulted in impaired chemotactic migration toward formyl-Met-Leu-Phe (fMLP) and stromal cell-derived factor 1α (SDF-1α) as well as decreased α5β1-integrin-mediated chemoattractant-stimulated adhesion. These GMFG knockdown impaired effects could be reversed by cotransfection of GFP-tagged full-length GMFG. GMFG knockdown cells reduced the cell surface and total protein levels of α5β1-integrin and increased its degradation. Importantly, we demonstrate that GMFG mediates the ubiquitination of β1-integrin through knockdown or overexpression of GMFG. Moreover, GMFG knockdown retarded the efficient recycling of β1-integrin back to the plasma membrane following normal endocytosis of α5β1-integrin, suggesting that the involvement of GMFG in maintaining α5β1-integrin stability may occur in part by preventing ubiquitin-mediated degradation and promoting β1-integrin recycling. Furthermore, we observed that GMFG interacted with syntaxin 4 (STX4) and syntaxin-binding protein 4 (STXBP4); however, only knockdown of STXBP4, but not STX4, reduced monocyte migration and decreased β1-integrin cell surface expression. Knockdown of STXBP4 also substantially inhibited β1-integrin recycling in human monocytes. These results indicate that the effects of GMFG on monocyte migration and adhesion probably occur through preventing ubiquitin-mediated proteasome degradation of α5β1-integrin and facilitating effective β1-integrin recycling back to the plasma membrane. PMID:26895964

Exposure of T lymphocytes to leflunomide but not to dexamethasone favors the production by monocytic cells of interleukin-1 receptor antagonist and the tissue-inhibitor of metalloproteinases-1 over that of interleukin-1beta and metalloproteinases.

PubMed

Déage, V; Burger, D; Dayer, J M

1998-12-01

On direct cell-cell contact, stimulated T lymphocytes potently trigger the production of pro-inflammatory factors such as interleukin-1beta (IL-1beta) and matrix metalloproteinases (MMP-1 and MMP-9), as well as anti-inflammatory factors such as IL-1 receptor antagonist (IL-1Ra) and the tissue inhibitor of metalloproteinases (TIMP-1) in peripheral blood monocytes and the monocytic cell line THP-1. Such mechanisms might play an important part in many inflammatory diseases where tissue destruction occurs. To assess whether anti-inflammatory agents such as dexamethasone (DEX) and leflunomide (LF) would affect contact-activation of monocytic cells, T lymphocytes were stimulated by PMA and PHA in the presence or absence of increasing concentrations of drug. LF and DEX (10- 4 M) inhibited the ability of stimulated T lymphocytes to activate monocytic cells by 66-97% and 43-70%, respectively, depending on the readout product. Upon contact with T lymphocytes stimulated in the presence of 10- 5 M LF, the molar ratio of IL-1Ra/IL-1beta and TIMP-1/MMP-1 produced by THP-1 cells was enhanced 3.6- and 1.9-fold, respectively, whereas it was enhanced only 1.3- and 1.4-fold upon contact with T lymphocytes stimulated in the presence of 10- 4 M DEX. Therefore, LF tends to favor the inhibition of pro-inflammatory and matrix-destructive factors over that of anti-inflammatory factors and metalloproteinase inhibitors, thus interfering with both inflammation and tissue destruction. These experiments indicate that LF and DEX have the potential to affect the capacity of stimulated T lymphocytes to activate, on direct cell-cell contact, monocytic cells. Furthermore, flow cytometric analysis revealed that surface molecules of T lymphocytes that were partially involved in contact-signaling of monocytes (i.e., CD69 and CD11) were not modulated by either LF or DEX, suggesting that factors which remain to be identified were mainly involved in the activation of monocytes on direct cell-cell contact.

Leishmania infection modulates beta-1 integrin activation and alters the kinetics of monocyte spreading over fibronectin.

PubMed

Figueira, Cláudio Pereira; Carvalhal, Djalma Gomes Ferrão; Almeida, Rafaela Andrade; Hermida, Micely d' El-Rei; Touchard, Dominique; Robert, Phillipe; Pierres, Anne; Bongrand, Pierre; dos-Santos, Washington L C

2015-08-07

Contact with Leishmania leads to a decreases in mononuclear phagocyte adherence to connective tissue. In this work, we studied the early stages of bond formation between VLA4 and fibronectin, measured the kinetics of membrane alignment and the monocyte cytoplasm spreading area over a fibronectin-coated surface, and studied the expression of high affinity integrin epitope in uninfected and Leishmania-infected human monocytes. Our results show that the initial VLA4-mediated interaction of Leishmania-infected monocyte with a fibronectin-coated surface is preserved, however, the later stage, leukocyte spreading over the substrate is abrogated in Leishmania-infected cells. The median of spreading area was 72 [55-89] μm(2) for uninfected and 41 [34-51] μm(2) for Leishmania-infected monocyte. This cytoplasm spread was inhibited using an anti-VLA4 blocking antibody. After the initial contact with the fibronectrin-coated surface, uninfected monocyte quickly spread the cytoplasm at a 15 μm(2) s(-1) ratio whilst Leishmania-infected monocytes only made small contacts at a 5.5 μm(2) s(-1) ratio. The expression of high affinity epitope by VLA4 (from 39 ± 21% to 14 ± 3%); and LFA1 (from 37 ± 32% to 18 ± 16%) molecules was reduced in Leishmania-infected monocytes. These changes in phagocyte function may be important for parasite dissemination and distribution of lesions in leishmaniasis.

Imatinib and Nilotinib Off-Target Effects on Human NK Cells, Monocytes, and M2 Macrophages.

PubMed

Bellora, Francesca; Dondero, Alessandra; Corrias, Maria Valeria; Casu, Beatrice; Regis, Stefano; Caliendo, Fabio; Moretta, Alessandro; Cazzola, Mario; Elena, Chiara; Vinti, Luciana; Locatelli, Franco; Bottino, Cristina; Castriconi, Roberta

2017-08-15

Tyrosine kinase inhibitors (TKIs) are used in the clinical management of hematological neoplasms. Moreover, in solid tumors such as stage 4 neuroblastomas (NB), imatinib showed benefits that might depend on both on-target and immunological off-target effects. We investigated the effects of imatinib and nilotinib on human NK cells, monocytes, and macrophages. High numbers of monocytes died upon exposure to TKI concentrations similar to those achieved in patients. Conversely, NK cells were highly resistant to the TKI cytotoxic effect, were properly activated by immunostimulatory cytokines, and degranulated in the presence of NB cells. In NB, neither drug reduced the expression of ligands for activating NK receptors or upregulated that of HLA class I, B7-H3, PD-L1, and PD-L2, molecules that might limit NK cell function. Interestingly, TKIs modulated the chemokine receptor repertoire of immune cells. Acting at the transcriptional level, they increased the surface expression of CXCR4, an effect observed also in NK cells and monocytes of patients receiving imatinib for chronic myeloid leukemia. Moreover, TKIs reduced the expression of CXCR3 (in NK cells) and CCR1 (in monocytes). Monocytes also decreased the expression of M-CSFR, and low numbers of cells underwent differentiation toward macrophages. M0 and M2 macrophages were highly resistant to TKIs and maintained their phenotypic and functional characteristics. Importantly, also in the presence of TKIs, the M2 immunosuppressive polarization was reverted by TLR engagement, and M1-oriented macrophages fully activated autologous NK cells. Our results contribute to better interpreting the off-target efficacy of TKIs in tumors and to envisaging strategies aimed at facilitating antitumor immune responses. Copyright © 2017 by The American Association of Immunologists, Inc.

The cachectic mediator proteolysis inducing factor activates NF-kappaB and STAT3 in human Kupffer cells and monocytes.

PubMed

Watchorn, Tammy M; Dowidar, Nabil; Dejong, Cornelis H C; Waddell, Ian D; Garden, O James; Ross, James A

2005-10-01

A novel proteoglycan, proteolysis inducing factor (PIF), is capable of inducing muscle proteolysis during the process of cancer cachexia, and of inducing an acute phase response in human hepatocytes. We investigated whether PIF is able to activate pro-inflammatory pathways in human Kupffer cells, the resident macrophages of the liver, and in monocytes, resulting in the production of pro-inflammatory cytokines. Normal liver tissue was obtained from patients undergoing partial hepatectomy and Kupffer cells were isolated. Monocytes were isolated from peripheral blood. Following exposure to native PIF, pro-inflammatory cytokine production from Kupffer cells and monocytes was measured and the NF-kappaB and STAT3 transcriptional pathways were investigated using electrophoretic mobility shift assays. We demonstrate that PIF is able to activate the transcription factor NF-kappaB and NF-kappaB-inducible genes in human Kupffer cells, and in monocytes, resulting in the production of pro-inflammatory cytokines such as TNF-alpha, IL-8 and IL-6. PIF enhances the expression of the cell surface molecules LFA-1 and CD14 on macrophages. PIF also activates the transcription factor STAT3 in Kupffer cells. The pro-inflammatory effects of PIF, mediated via NF-kappaB and STAT3, are important in macrophage behaviour and may contribute to the inflammatory pro-cachectic process in the liver.

The distribution of IL-13 receptor alpha1 expression on B cells, T cells and monocytes and its regulation by IL-13 and IL-4.

PubMed

Graber, P; Gretener, D; Herren, S; Aubry, J P; Elson, G; Poudrier, J; Lecoanet-Henchoz, S; Alouani, S; Losberger, C; Bonnefoy, J Y; Kosco-Vilbois, M H; Gauchat, J F

1998-12-01

To study the expression of IL-13 receptor alpha1 (IL-13Ralpha1), specific monoclonal antibodies (mAb) were generated. Surface expression of the IL-13Ralpha1 on B cells, monocytes and T cells was assessed by flow cytometry using these specific mAb. Among tonsillar B cells, the expression was the highest on the IgD+ CD38- B cell subpopulation which is believed to represent naive B cells. Expression was also detectable on a large fraction of the IgD-CD38- B cells but not on CD38+ B cells. Activation under conditions which promote B cell Ig class switching up-regulated the expression of the receptor. However, the same stimuli had an opposite effect for IL-13Ralpha1 expression levels on monocytes. While IL-13Ralpha1 mRNA was clearly detectable in T cell preparations, no surface expression was detected. However, permeabilization of the T cells showed a clear intracellular expression of the receptor. A soluble form of the receptor was immunoprecipitated from the supernatant of activated peripheral T cells, suggesting that T cell IL-13Ralpha1 might have functions unrelated to the capacity to form a type II IL-4/IL-13R with IL-4Ralpha.

Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

PubMed Central

Messlinger, Helena; Sebald, Heidi; Heger, Lukas; Dudziak, Diana; Bogdan, Christian; Schleicher, Ulrike

2018-01-01

Activated natural killer (NK) cells release interferon (IFN)-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani). When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis) were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL)-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs) of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells reduced the expression of CD56 mRNA and protein on NK cells. We conclude that Leishmania activate NK cells via trans-presentation of IL-18 by monocytes and by a monocyte-derived soluble factor. IL-12 is needed to elicit the IFN-γ-response of NK cells, which is likely to be an important component of the innate control of the parasite. PMID:29472914

Amyloid-β peptide on sialyl-Lewis(X)-selectin-mediated membrane tether mechanics at the cerebral endothelial cell surface.

PubMed

Askarova, Sholpan; Sun, Zhe; Sun, Grace Y; Meininger, Gerald A; Lee, James C-M

2013-01-01

Increased deposition of amyloid-β peptide (Aβ) at the cerebral endothelial cell (CEC) surface has been implicated in enhancement of transmigration of monocytes across the brain blood barrier (BBB) in Alzheimer's disease (AD). In this study, quantitative immunofluorescence microscopy (QIM) and atomic force microscopy (AFM) with cantilevers biofunctionalized by sialyl-Lewis(x) (sLe(x)) were employed to investigate Aβ-altered mechanics of membrane tethers formed by bonding between sLe(x) and p-selectin at the CEC surface, the initial mechanical step governing the transmigration of monocytes. QIM results indicated the ability for Aβ to increase p-selectin expression at the cell surface and promote actin polymerization in both bEND3 cells (immortalized mouse CECs) and human primary CECs. AFM data also showed the ability for Aβ to increase cell stiffness and adhesion probability in bEND3 cells. On the contrary, Aβ lowered the overall force of membrane tether formation (Fmtf ), and produced a bimodal population of Fmtf , suggesting subcellular mechanical alterations in membrane tethering. The lower Fmtf population was similar to the results obtained from cells treated with an F-actin-disrupting drug, latrunculin A. Indeed, AFM results also showed that both Aβ and latrunculin A decreased membrane stiffness, suggesting a lower membrane-cytoskeleton adhesion, a factor resulting in lower Fmtf . In addition, these cerebral endothelial alterations induced by Aβ were abrogated by lovastatin, consistent with its anti-inflammatory effects. In sum, these results demonstrated the ability for Aβ to enhance p-selectin expression at the CEC surface and induce cytoskeleton reorganization, which in turn, resulted in changes in membrane-cytoskeleton adhesion and membrane tethering, mechanical factors important in transmigration of monocytes through the BBB.

Amyloid-β Peptide on Sialyl-LewisX-Selectin-Mediated Membrane Tether Mechanics at the Cerebral Endothelial Cell Surface

PubMed Central

Askarova, Sholpan; Sun, Zhe; Sun, Grace Y.; Meininger, Gerald A.; Lee, James C-M.

2013-01-01

Increased deposition of amyloid-β peptide (Aβ) at the cerebral endothelial cell (CEC) surface has been implicated in enhancement of transmigration of monocytes across the brain blood barrier (BBB) in Alzheimer's disease (AD). In this study, quantitative immunofluorescence microscopy (QIM) and atomic force microscopy (AFM) with cantilevers biofunctionalized by sialyl-Lewisx (sLex) were employed to investigate Aβ-altered mechanics of membrane tethers formed by bonding between sLex and p-selectin at the CEC surface, the initial mechanical step governing the transmigration of monocytes. QIM results indicated the ability for Aβ to increase p-selectin expression at the cell surface and promote actin polymerization in both bEND3 cells (immortalized mouse CECs) and human primary CECs. AFM data also showed the ability for Aβ to increase cell stiffness and adhesion probability in bEND3 cells. On the contrary, Aβ lowered the overall force of membrane tether formation (Fmtf), and produced a bimodal population of Fmtf, suggesting subcellular mechanical alterations in membrane tethering. The lower Fmtf population was similar to the results obtained from cells treated with an F-actin-disrupting drug, latrunculin A. Indeed, AFM results also showed that both Aβ and latrunculin A decreased membrane stiffness, suggesting a lower membrane-cytoskeleton adhesion, a factor resulting in lower Fmtf. In addition, these cerebral endothelial alterations induced by Aβ were abrogated by lovastatin, consistent with its anti-inflammatory effects. In sum, these results demonstrated the ability for Aβ to enhance p-selectin expression at the CEC surface and induce cytoskeleton reorganization, which in turn, resulted in changes in membrane-cytoskeleton adhesion and membrane tethering, mechanical factors important in transmigration of monocytes through the BBB. PMID:23593361

Pancreatic cancer cell/fibroblast co-culture induces M2 like macrophages that influence therapeutic response in a 3D model

PubMed Central

Kuen, Janina; Darowski, Diana; Kluge, Tobias

2017-01-01

Pancreatic cancer (PC) remains one of the most challenging solid tumors to treat with a high unmet medical need as patients poorly respond to standard-of-care-therapies. Prominent desmoplastic reaction involving cancer-associated fibroblasts (CAFs) and the immune cells in the tumor microenvironment (TME) and their cross-talk play a significant role in tumor immune escape and progression. To identify the key cellular mechanisms induce an immunosuppressive tumor microenvironment, we established 3D co-culture model with pancreatic cancer cells, CAFs and monocytes. Using this model, we analyzed the influence of tumor cells and fibroblasts on monocytes and their immune suppressive phenotype. Phenotypic characterization of the monocytes after 3D co-culture with tumor/fibroblast spheroids was performed by analyzing the expression of defined cell surface markers and soluble factors. Functionality of these monocytes and their ability to influence T cell phenotype and proliferation was investigated. 3D co-culture of monocytes with pancreatic cancer cells and fibroblasts induced the production of immunosuppressive cytokines which are known to promote polarization of M2 like macrophages and myeloid derived suppressive cells (MDSCs). These co-culture spheroid polarized monocyte derived macrophages (MDMs) were poorly differentiated and had an M2 phenotype. The immunosuppressive function of these co-culture spheroids polarized MDMs was demonstrated by their ability to inhibit CD4+ and CD8+ T cell activation and proliferation in vitro, which we could partially reverse by 3D co-culture spheroid treatment with therapeutic molecules that are able to re-activated spheroid polarized MDMs or block immune suppressive factors such as Arginase-I. PMID:28750018

Lipoprotein lipase-dependent binding and uptake of low density lipoproteins by THP-1 monocytes and macrophages: possible involvement of lipid rafts.

PubMed

Makoveichuk, Elena; Castel, Susanna; Vilaró, Senen; Olivecrona, Gunilla

2004-11-08

Lipoprotein lipase (LPL) is produced by cells in the artery wall and can mediate binding of lipoproteins to cell surface heparan sulfate proteoglycans (HSPG), resulting in endocytosis (the bridging function). Active, dimeric LPL may dissociate to inactive monomers, the main form found in plasma. We have studied binding/internalization of human low density lipoprotein (LDL), mediated by bovine LPL, using THP-1 monocytes and macrophages. Uptake of (125)I-LDL was similar in monocytes and macrophages and was not affected by the LDL-receptor family antagonist receptor-associated protein (RAP) or by the phagocytosis inhibitor cytochalasin D. In contrast, uptake depended on HSPG and on membrane cholesterol. Incubation in the presence of dexamethasone increased the endogenous production of LPL by the cells and also increased LPL-mediated binding of LDL to the cell surfaces. Monomeric LPL was bound to the cells mostly in a heparin-resistant fashion. We conclude that the uptake of LDL mediated by LPL dimers is receptor-independent and involves cholesterol-enriched membrane areas (lipid rafts). Dimeric and monomeric LPL differ in their ability to mediate binding/uptake of LDL, probably due to different mechanisms for binding/internalization.

Directional budding of human immunodeficiency virus from monocytes.

PubMed Central

Perotti, M E; Tan, X; Phillips, D M

1996-01-01

Time-lapse cinematography revealed that activated human immunodeficiency virus (HIV)-infected monocytes crawl along surfaces, putting forward a leading pseudopod. Scanning electron micrographs showed monocyte pseudopods associated with spherical structures the size of HIV virions, and transmission electron micrographs revealed HIV virions budding from pseudopods. Filamentous actin (F-actin) was localized by electron microscopy in the pseudopod by heavy meromyosin decoration. Colocalization of F-actin and p24 viral antigen by light microscopy immunofluorescence indicated that F-actin and virus were present on the same pseudopod. These observations indicate that monocytes produce virus from a leading pseudopod. We suggest that HIV secretion at the leading edges of donor monocytes/macrophages may be an efficient way for HIV to infect target cells. PMID:8709212

The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur.

PubMed

Kim, Su-Han; Ko, Hyun-Chang; Kim, Moon-Bum; Kwon, Kyung-Sool; Oh, Chang-Keun

2009-05-01

Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-alpha, IL-6 and IL-1beta in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-alpha were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done.

Expression of myeloid differentiation antigens on normal and malignant myeloid cells.

PubMed Central

Griffin, J D; Ritz, J; Nadler, L M; Schlossman, S F

1981-01-01

A series of monoclonal antibodies have been characterized that define four surface antigens (MY3, MY4, MY7, and MY8) of human myeloid cells. They were derived from a fusion of the NS-1 plasmacytoma cell line with splenocytes from a mouse immunized with human acute myelomonocytic leukemia cells. MY3 and MY4 are expressed by normal monocytes and by greater than 90% of patients with acute monocytic leukemia or acute myelomonocytic leukemia, but are detected much less often on other types of myeloid leukemia. MY7 is expressed by granulocytes, monocytes, and 5% of normal bone marrow cells. 79% of all acute myeloblastic leukemia (AML) patients tested (72 patients) express MY7 without preferential expression by any AML subtype. MY8 is expressed by normal monocytes, granulocytes, all peroxidase-positive bone marrow cells, and 50% of AML patients. MY3, MY4, and MY8 define myeloid differentiation antigens in that they are not detected on myeloid precursor cells and appear at discrete stages of differentiation. These antigens are not expressed by lymphocytes, erythrocytes, platelets, or lymphoid malignancies. The monoclonal antisera defining these antigens have been used to study differentiation of normal myeloid cells and malignant cell lines. Images PMID:6945311

The role of proteinase 3 (PR3) and the protease-activated receptor-2 (PAR-2) pathway in dendritic cell (DC) maturation of human-DC-like monocytes and murine DC.

PubMed

Jiang, Bo; Grage-Griebenow, Evelin; Csernok, Elena; Butherus, Kristine; Ehlers, Stefan; Gross, Wolfgang L; Holle, Julia U

2010-01-01

The aim of the study was to assess PAR-2 expression on dendritic cell (DC) subsets and other immune cells of Wegener's granulomatosis (WG) patients and healthy controls (HC) and to investigate whether Proteinase 3 (PR3, a serine protease which can activate PAR2) induces maturation of human DC-like monocytes and murine Flt-3 ligand- and GM-CSF-generated DC. Human peripheral blood cells including DC subsets and Flt-3l- and GM-CSF-generated mouse DC were analysed for expression of PAR-2 and DC maturation markers by flow cytometry before and after stimulation with PR3, trypsin, PAR-2 agonist or LPS for 24 h. There was no difference of PAR-2 expression on PMNs, monocytes, lymphocytes and DC between all WG samples and HC. However, in inactive WG, expression of PAR-2 was downregulated on the cell surface of PMNs, monocytes, lymphocytes, and CD11c+DC compared to active WG and HC. PR3 and PAR2-agonists did not induce upregulation of PAR-2 or maturation markers of human DC-like monocytes in WG and HC. Likewise, murine PR3 did not induce upregulation of PAR-2 or maturation markers in murine DC. PAR-2 expression is downregulated on human peripheral blood cells including CD11c+ DC in inactive WG compared to active WG and HC, possibly reflecting a non-activated status of these cells in inactive disease. PR3 and PAR-2- agonists did not induce maturation of human ex vivo DC-like monocytes in WG and HC and of murine DC, suggesting this pathway is not singularly involved in the maturation of these cell subsets.

Leishmania infection modulates beta-1 integrin activation and alters the kinetics of monocyte spreading over fibronectin

PubMed Central

Figueira, Cláudio Pereira; Carvalhal, Djalma Gomes Ferrão; Almeida, Rafaela Andrade; Hermida, Micely d’ El-Rei; Touchard, Dominique; Robert, Phillipe; Pierres, Anne; Bongrand, Pierre; dos-Santos, Washington LC

2015-01-01

Contact with Leishmania leads to a decreases in mononuclear phagocyte adherence to connective tissue. In this work, we studied the early stages of bond formation between VLA4 and fibronectin, measured the kinetics of membrane alignment and the monocyte cytoplasm spreading area over a fibronectin-coated surface, and studied the expression of high affinity integrin epitope in uninfected and Leishmania-infected human monocytes. Our results show that the initial VLA4-mediated interaction of Leishmania-infected monocyte with a fibronectin-coated surface is preserved, however, the later stage, leukocyte spreading over the substrate is abrogated in Leishmania-infected cells. The median of spreading area was 72 [55–89] μm2 for uninfected and 41 [34–51] μm2 for Leishmania-infected monocyte. This cytoplasm spread was inhibited using an anti-VLA4 blocking antibody. After the initial contact with the fibronectrin-coated surface, uninfected monocyte quickly spread the cytoplasm at a 15 μm2 s−1 ratio whilst Leishmania-infected monocytes only made small contacts at a 5.5 μm2 s−1 ratio. The expression of high affinity epitope by VLA4 (from 39 ± 21% to 14 ± 3%); and LFA1 (from 37 ± 32% to 18 ± 16%) molecules was reduced in Leishmania-infected monocytes. These changes in phagocyte function may be important for parasite dissemination and distribution of lesions in leishmaniasis. PMID:26249106

Regulation of ICAM-1 in cells of the monocyte/macrophage system in microgravity.

PubMed

Paulsen, Katrin; Tauber, Svantje; Dumrese, Claudia; Bradacs, Gesine; Simmet, Dana M; Gölz, Nadine; Hauschild, Swantje; Raig, Christiane; Engeli, Stephanie; Gutewort, Annett; Hürlimann, Eva; Biskup, Josefine; Unverdorben, Felix; Rieder, Gabriela; Hofmänner, Daniel; Mutschler, Lisa; Krammer, Sonja; Buttron, Isabell; Philpot, Claudia; Huge, Andreas; Lier, Hartwin; Barz, Ines; Engelmann, Frank; Layer, Liliana E; Thiel, Cora S; Ullrich, Oliver

2015-01-01

Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells.

Regulation of ICAM-1 in Cells of the Monocyte/Macrophage System in Microgravity

PubMed Central

Paulsen, Katrin; Tauber, Svantje; Dumrese, Claudia; Bradacs, Gesine; Simmet, Dana M.; Gölz, Nadine; Hauschild, Swantje; Raig, Christiane; Engeli, Stephanie; Gutewort, Annett; Hürlimann, Eva; Biskup, Josefine; Rieder, Gabriela; Hofmänner, Daniel; Mutschler, Lisa; Krammer, Sonja; Philpot, Claudia; Huge, Andreas; Lier, Hartwin; Barz, Ines; Engelmann, Frank; Layer, Liliana E.; Thiel, Cora S.

2015-01-01

Cells of the immune system are highly sensitive to altered gravity, and the monocyte as well as the macrophage function is proven to be impaired under microgravity conditions. In our study, we investigated the surface expression of ICAM-1 protein and expression of ICAM-1 mRNA in cells of the monocyte/macrophage system in microgravity during clinostat, parabolic flight, sounding rocket, and orbital experiments. In murine BV-2 microglial cells, we detected a downregulation of ICAM-1 expression in clinorotation experiments and a rapid and reversible downregulation in the microgravity phase of parabolic flight experiments. In contrast, ICAM-1 expression increased in macrophage-like differentiated human U937 cells during the microgravity phase of parabolic flights and in long-term microgravity provided by a 2D clinostat or during the orbital SIMBOX/Shenzhou-8 mission. In nondifferentiated U937 cells, no effect of microgravity on ICAM-1 expression could be observed during parabolic flight experiments. We conclude that disturbed immune function in microgravity could be a consequence of ICAM-1 modulation in the monocyte/macrophage system, which in turn could have a strong impact on the interaction with T lymphocytes and cell migration. Thus, ICAM-1 can be considered as a rapid-reacting and sustained gravity-regulated molecule in mammalian cells. PMID:25654110

Biophysical regulation of Chlamydia pneumoniae-infected monocyte recruitment to atherosclerotic foci

NASA Astrophysics Data System (ADS)

Evani, Shankar J.; Ramasubramanian, Anand K.

2016-01-01

Chlamydia pneumoniae infection is implicated in atherosclerosis although the contributory mechanisms are poorly understood. We hypothesize that C. pneumoniae infection favors the recruitment of monocytes to atherosclerotic foci by altering monocyte biophysics. Primary, fresh human monocytes were infected with C. pneumoniae for 8 h, and the interactions between monocytes and E-selectin or aortic endothelium under flow were characterized by video microscopy and image analysis. The distribution of membrane lipid rafts and adhesion receptors were analyzed by imaging flow cytometry. Infected cells rolled on E-selectin and endothelial surfaces, and this rolling was slower, steady and uniform compared to uninfected cells. Infection decreases cholesterol levels, increases membrane fluidity, disrupts lipid rafts, and redistributes CD44, which is the primary mediator of rolling interactions. Together, these changes translate to higher firm adhesion of infected monocytes on endothelium, which is enhanced in the presence of LDL. Uninfected monocytes treated with LDL or left untreated were used as baseline control. Our results demonstrate that the membrane biophysical changes due to infection and hyperlipidemia are one of the key mechanisms by which C. pneumoniae can exacerbate atherosclerotic pathology. These findings provide a framework to characterize the role of ‘infectious burden’ in the development and progression of atherosclerosis.

Cytokines and macrophage function in humans - role of stress

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald (Principal Investigator)

1996-01-01

We have begun this study to commence the determination of the role of mild chronic stress in the effects of space flight on macrophage/monocyte function, a component of the immune response. Medical students undergoing regular periods of stress and relaxation have been shown to be an excellent model for determining the effects of stress on immune responses. We have begun using this model using the macrophage/monocyte as model leukocyte. The monocyte/macrophage plays a central role in immunoregulation. The studies to be included in this three year project are the effects of stress on: (1) interactions of monocytes with microbes, (2) monocyte production of cytokines, (3) monocyte phagocytosis and activity, and (4) monocyte expression of cell surface antigens important in immune responses. Stress hormone levels will also be carried out to determine if there is a correlation between stress effects on immune responses and hormonal levels. Psychological testing to insure subjects are actually stressed or relaxed at the time of testing will also be carried out. The results obtained from the proposed studies should be comparable with space flight studies with whole animals and isolated cell cultures. When complete this study should allow the commencement of the establishment of the role of stress as one compartment of the induction of immune alterations by space flight.

Effect of gold nanoparticle size and coating on labeling monocytes for CT tracking

PubMed Central

Chhour, Peter; Kim, Johoon; Benardo, Barbara; Tovar, Alfredo; Mian, Shaameen; Litt, Harold I.; Ferrari, Victor A.; Cormode, David P.

2017-01-01

With advances in cell therapies, interest in cell tracking techniques to monitor the migration, localization and viability of these cells continues to grow. X-ray computed tomography (CT) is a cornerstone of medical imaging but has been limited in cell tracking applications due to its low sensitivity towards contrast media. In this study, we investigate the role of size and surface functionality of gold nanoparticles for monocyte uptake to optimize the labeling of these cells for tracking in CT. We synthesized gold nanoparticles (AuNP) that range from 15 to 150 nm in diameter and examined several capping ligands, generating 44 distinct AuNP formulations. In vitro cytotoxicity and uptake experiments were performed with the RAW 264.7 monocyte cell line. The majority of formulations at each size were found to be biocompatible, with only certain 150 nm PEG functionalized particles reducing viability at high concentrations. High uptake of AuNP was found using small capping ligands with distal carboxylic acids (11-MUA and 16-MHA). Similar uptake values were found with intermediate sizes (50 and 75 nm) of AuNP when coated with 2000 MW poly(ethylene-glycol) carboxylic acid ligands (PCOOH). Low uptake values were observed with 15, 25, 100, and 150 nm PCOOH AuNP, revealing interplay between size and surface functionality. TEM and CT performed on cells revealed similar patterns of high gold uptake for 50 nm PCOOH and 75 nm PCOOH AuNP. These results demonstrate that highly negatively charged carboxylic acid coatings for AuNP provide the greatest internalization of AuNP in monocytes, with a complex dependency on size. PMID:28095688

JAM-A and ALCAM are therapeutic targets to inhibit diapedesis across the BBB of CD14+CD16+ monocytes in HIV-infected individuals.

PubMed

Williams, Dionna W; Anastos, Kathryn; Morgello, Susan; Berman, Joan W

2015-02-01

Monocyte transmigration across the BBB is a critical step in the development of cognitive deficits termed HAND that affect 40-70% of HIV-infected individuals, even with successful antiretroviral therapy. The monocyte subsets that enter the CNS during HIV infection are not fully characterized. We examined PBMC from HIV-positive individuals from 2 distinct cohorts and enumerated monocyte populations, characterized their transmigration properties across an in vitro human BBB model, and identified surface proteins critical for the entry of these cells into the CNS. We demonstrated that the frequency of peripheral blood CD14(+)CD16(+) and CD14(low)CD16(+) monocytes was increased in HIV-seropositive compared with -seronegative individuals, despite virologic control. We showed that CD14(+)CD16(+) monocytes selectively transmigrated across our BBB model as a result of their increased JAM-A and ALCAM expression. Antibody blocking of these proteins inhibited diapedesis of CD14(+)CD16(+) monocytes but not of T cells from the same HIV-infected people across the BBB. Our data indicate that JAM-A and ALCAM are therapeutic targets to decrease the entry of CD14(+)CD16(+) monocytes into the CNS of HIV-seropositive individuals, contributing to the eradication of neuroinflammation, HAND, and CNS viral reservoirs. © Society for Leukocyte Biology.

Inhibition of cell surface mediated plasminogen activation by a monoclonal antibody against alpha-Enolase.

PubMed

López-Alemany, Roser; Longstaff, Colin; Hawley, Stephen; Mirshahi, Massoud; Fábregas, Pere; Jardí, Merce; Merton, Elizabeth; Miles, Lindsey A; Félez, Jordi

2003-04-01

Localization of plasmin activity on leukocyte surfaces plays a critical role in fibrinolysis as well as in pathological and physiological processes in which cells must degrade the extracellular matrix in order to migrate. The binding of plasminogen to leukocytic cell lines induces a 30- to 80-fold increase in the rate of plasminogen activation by tissue-type (tPA) and urokinase-type (uPA) plasminogen activators. In the present study we have examined the role of alpha-enolase in plasminogen activation on the cell surface. We produced and characterized a monoclonal antibody (MAb) 11G1 against purified alpha-enolase, which abrogated about 90% of cell-dependent plasminogen activation by either uPA or tPA on leukocytoid cell lines of different lineages: B-lymphocytic, T-lymphocytic, granulocytic, and monocytic cells. In addition, MAb 11G1 also blocked enhancement of plasmin formation by peripheral blood neutrophils and monocytes. In contrast, MAb 11G1 did not affect plasmin generation in the presence of fibrin, indicating that this antibody did not interact with fibrinolytic components in the absence of cells. These data suggest that, although leukocytic cells display several molecules that bind plasminogen, alpha-enolase is responsible for the majority of the promotion of plasminogen activation on the surfaces of leukocytic cells. Copyright 2003 Wiley-Liss, Inc.

ADMA induces monocyte adhesion via activation of chemokine receptors in cultured THP-1 cells.

PubMed

Chen, Meifang; Li, Yuanjian; Yang, Tianlun; Wang, Yongjin; Bai, Yongping; Xie, Xiumei

2008-08-01

Asymmetric dimethylarginine (ADMA), an endogenous NOS inhibitor, is also an important inflammatory factor contributing to the development of atherosclerosis (AS). The present study was to test the effect of ADMA on angiotensin (Ang) II-induced monocytic adhesion. Human monocytoid cells (THP-1) or isolated peripheral blood monocyte cells (PBMCs) were incubated with Ang II (10(-6)M) or exogenous ADMA (30 microM) for 4 or 24h in the absence or presence of losartan or antioxidant PDTC. In cultured THP-1 cells, Ang II (10(-6)M) for 24h elevated the level of ADMA in the medium, upregulated the protein expression of protein arginine methyltransferase (PRMT) and decreased the activity of dimethylarginine dimethylaminohydrolase (DDAH). Both of Ang II and ADMA increased monocytic adhesion to human umbilical vein endothelial cells (HUVECs), elevated the levels of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha and upregulated CCR(2) and CXCR(2) mRNA expression, concomitantly with increase in reactive oxygen species (ROS) generation and activation of nuclear factor (NF)-kappaB. Pretreatment with losartan (10 microM) or PDTC (10 microM) abolished the effects mediated by Ang II or ADMA. In isolated PBMCs from healthy individuals, ADMA upregulated the expression of CXCR(2) mRNA, which was attenuated by losartan (10 microM), however, ADMA had no effect on surface protein expression of CCR(2). The present results suggest that ADMA may be involved in monocytic adhesion induced by Ang II via activation of chemokine receptors by ROS/NF-kappaB pathway.

Estradiol coupling to human monocyte nitric oxide release is dependent on intracellular calcium transients: evidence for an estrogen surface receptor.

PubMed

Stefano, G B; Prevot, V; Beauvillain, J C; Fimiani, C; Welters, I; Cadet, P; Breton, C; Pestel, J; Salzet, M; Bilfinger, T V

1999-10-01

We tested the hypothesis that estrogen acutely stimulates constitutive NO synthase (cNOS) activity in human peripheral monocytes by acting on an estrogen surface receptor. NO release was measured in real time with an amperometric probe. 17beta-estradiol exposure to monocytes stimulated NO release within seconds in a concentration-dependent manner, whereas 17alpha-estradiol had no effect. 17beta-estradiol conjugated to BSA (E2-BSA) also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor inhibitor, antagonized the action of both 17beta-estradiol and E2-BSA, whereas ICI 182,780, a selective inhibitor of the nuclear estrogen receptor, had no effect. We further showed, using a dual emission microfluorometry in a calcium-free medium, that the 17beta-estradiol-stimulated release of monocyte NO was dependent on the initial stimulation of intracellular calcium transients in a tamoxifen-sensitive process. Leeching out the intracellular calcium stores abolished the effect of 17beta-estradiol on NO release. RT-PCR analysis of RNA obtained from the cells revealed a strong estrogen receptor-alpha amplification signal and a weak beta signal. Taken together, a physiological dose of estrogen acutely stimulates NO release from human monocytes via the activation of an estrogen surface receptor that is coupled to increases in intracellular calcium.

In vitro study on bone formation and surface topography from the standpoint of biomechanics.

PubMed

Kawahara, H; Soeda, Y; Niwa, K; Takahashi, M; Kawahara, D; Araki, N

2004-12-01

Effect of surface topography upon cell-adhesion, -orientation and -differentiation was investigated by in vitro study on cellular responses to titanium substratum with different surface roughness. Cell-shape, -function and -differentiation depending upon the surface topography were clarified by use of bone formative group cells (BFGCs) derived from bone marrow of beagle's femur. BFGCs consisted of hematopoietic stem cells (HSC) and osteogenetic stem cells (OSC). Cell differentiation of BFGCs was expressed and promoted by structural changes of cytoskeleton, and cell-organella, which was caused by mechanical stress with cytoplasmic stretching of cell adhesions to the substratum. Phagocytic monocytes of HSC differentiated to osteomediator cells (OMC) by cytoplasmic stretching with cell adhesion to the substratum. The OMC mediated and promoted cell differentiation from OSC to osteoblast through osteoblastic phenotype cell (OBC) by cell-aggregation of nodules with "pile up" phenomenon of OBC onto OMC. The osteogenesis might be performed by coupling work of both cells, OMC originated from monocyte of HSC and OBC originated from OSC, which were explained by SEM, TEM and fluorescent probe investigation on BFGCs on the test plate of cp titanium plates with different topographies. This osteogenetic process was proved by investigating cell proliferation, DNA contents, cell-adhesion, alkaline phosphatase activity and osteocalcine productivity for cells on the titanium plates with different topographies. The study showed increased osteogenic effects for cells cultured on Ti with increased surface roughness. Possible mechanisms were discussed from a biomechanical perspective.

Peripheral blood "endothelial progenitor cells" are derived from monocyte/macrophages and secrete angiogenic growth factors.

PubMed

Rehman, Jalees; Li, Jingling; Orschell, Christie M; March, Keith L

2003-03-04

Endothelial progenitor cells (EPCs) have been isolated from peripheral blood and can enhance angiogenesis after infusion into host animals. It is not known whether the proangiogenic effects are a result of such events as endothelial differentiation and subsequent proliferation of EPCs or secondary to secretion of angiogenic growth factors. Human EPCs were isolated as previously described, and their phenotypes were confirmed by uptake of acetylated LDL and binding of ulex-lectin. EPC proliferation and surface marker expression were analyzed by flow cytometry, and conditioned medium was assayed for growth factors. The majority of EPCs expressed monocyte/macrophage markers such as CD14 (95.7+/-0.3%), Mac-1 (57.6+/-13.5%), and CD11c (90.8+/-4.9%). A much lower percentage of cells expressed the specific endothelial marker VE-cadherin (5.2+/-0.7%) or stem/progenitor-cell markers AC133 (0.16+/-0.05%) and c-kit (1.3+/-0.7%). Compared with circulating monocytes, cultured EPCs showed upregulation of monocyte activation and macrophage differentiation markers. EPCs did not demonstrate any significant proliferation but did secrete the angiogenic growth factors vascular endothelial growth factor, hepatocyte growth factor, granulocyte colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor. Our findings suggest that acetylated LDL(+)ulex-lectin(+) cells, commonly referred to as EPCs, do not proliferate but release potent proangiogenic growth factors. The majority of acetylated LDL(+)ulex-lectin(+) cells are derived from monocyte/macrophages. The findings of low proliferation and endothelial differentiation suggest that their angiogenic effects are most likely mediated by growth factor secretion. These findings may allow for development of novel angiogenic therapies relying on secreted growth factors or on recruitment of endogenous monocytes/macrophages to sites of ischemia.

Cell–specific Variation in E-selectin Ligand Expression Among Human Peripheral Blood Mononuclear Cells: Implications for Immunosurveillance and Pathobiology

PubMed Central

Silva, Mariana; Fung, Ronald Kam Fai; Donnelly, Conor Brian; Videira, Paula Alexandra; Sackstein, Robert

2017-01-01

Both host defense and immunopathology are shaped by the ordered recruitment of circulating leukocytes to affected sites, a process initiated by binding of blood-borne cells to E-selectin displayed at target endothelial beds. Accordingly, knowledge of the expression and function of leukocyte E-selectin ligands is key to understanding the tempo and specificity of immunoreactivity. Here, we performed E-selectin adherence assays under hemodynamic flow conditions coupled with flow cytometry and western blot analysis to elucidate the function and structural biology of glycoprotein E-selectin ligands expressed on human peripheral blood mononuclear cells (PBMCs). Circulating monocytes uniformly express high levels of the canonical E-selectin binding determinant sLeX and display markedly greater adhesive interactions with E-selectin than do circulating lymphocytes, which exhibit variable E-selectin binding among CD4+ and CD8+ T-cells but no binding by B-cells. Monocytes prominently present sLeX decorations on an array of protein scaffolds including PSGL-1, CD43, and CD44 (rendering the E-selectin ligands CLA, CD43E, and HCELL, respectively), and B-cells altogether lack E-selectin ligands. Quantitative PCR gene expression studies of glycosyltransferases that regulate display of sLeX reveal high transcript levels among circulating monocytes and low levels among circulating B-cells, and, commensurately, cell surface α(1,3)-fucosylation reveals that acceptor sialyllactosaminyl glycans convertible into sLeX are abundantly expressed on human monocytes yet are relatively deficient on B-cells. Collectively, these findings unveil distinct cell-specific patterns of E-selectin ligand expression among human PBMCs, indicating that circulating monocytes are specialized to engage E-selectin and providing key insights into the molecular effectors mediating recruitment of these cells at inflammatory sites. PMID:28330896

Activation of Coagulation by Lenalidomide-Based Regimens for the Treatment of Multiple Myeloma

PubMed Central

Isozumi, Yu; Arai, Reina; Fujimoto, Kazumi; Koyama, Takatoshi

2013-01-01

We investigated the procoagulant effects of lenalidomide (Len)-based regimens in vitro focusing on tissue factor (TF) and phosphatidylserine (PS). We examined the effects of a pharmacological concentration of Len with or without the corticosteroid dexamethasone (Dex) and the proteasome inhibitor bortezomib (Bor) using the human vascular endothelial cell line EAhy926 and the monocytic cell lines THP-1 and U937. Cell-surface procoagulant activity (PCA) was induced by Dex-containing regimens in all lines. Expression of TF antigen on the cell surface and of TF mRNA was markedly increased by Dex-containing regimens. PS exposure was increased modestly by a Len-based regimen. PS exposure was increased modestly in EAhy926 cells, and markedly increased in THP-1 and U937 cells by Bor-containing treatment. An anti-TF monoclonal antibody almost completely blocked the induced PCA. When Len is given in combination with Dex, PCA may be induced on endothelial cells and monocytes through TF expression and PS exposure. PMID:23696885

Activation of coagulation by lenalidomide-based regimens for the treatment of multiple myeloma.

PubMed

Isozumi, Yu; Arai, Reina; Fujimoto, Kazumi; Koyama, Takatoshi

2013-01-01

We investigated the procoagulant effects of lenalidomide (Len)-based regimens in vitro focusing on tissue factor (TF) and phosphatidylserine (PS). We examined the effects of a pharmacological concentration of Len with or without the corticosteroid dexamethasone (Dex) and the proteasome inhibitor bortezomib (Bor) using the human vascular endothelial cell line EAhy926 and the monocytic cell lines THP-1 and U937. Cell-surface procoagulant activity (PCA) was induced by Dex-containing regimens in all lines. Expression of TF antigen on the cell surface and of TF mRNA was markedly increased by Dex-containing regimens. PS exposure was increased modestly by a Len-based regimen. PS exposure was increased modestly in EAhy926 cells, and markedly increased in THP-1 and U937 cells by Bor-containing treatment. An anti-TF monoclonal antibody almost completely blocked the induced PCA. When Len is given in combination with Dex, PCA may be induced on endothelial cells and monocytes through TF expression and PS exposure.

Complement-Mediated Enhancement of Monocyte Adhesion to Endothelial Cells by HLA Antibodies, and Blockade by a Specific Inhibitor of the Classical Complement Cascade, TNT003

PubMed Central

Valenzuela, Nicole M.; Thomas, Kimberly A.; Mulder, Arend; Parry, Graham C.; Panicker, Sandip; Reed, Elaine F.

2017-01-01

Background Antibody-mediated rejection (AMR) of most solid organs is characterized by evidence of complement activation and/or intragraft macrophages (C4d + and CD68+ biopsies). We previously demonstrated that crosslinking of HLA I by antibodies triggered endothelial activation and monocyte adhesion. We hypothesized that activation of the classical complement pathway at the endothelial cell surface by HLA antibodies would enhance monocyte adhesion through soluble split product generation, in parallel with direct endothelial activation downstream of HLA signaling. Methods Primary human aortic endothelial cells (HAEC) were stimulated with HLA class I antibodies in the presence of intact human serum complement. C3a and C5a generation, endothelial P-selectin expression, and adhesion of human primary and immortalized monocytes (Mono Mac 6) were measured. Alternatively, HAEC or monocytes were directly stimulated with purified C3a or C5a. Classical complement activation was inhibited by pretreatment of complement with an anti-C1s antibody (TNT003). Results Treatment of HAEC with HLA antibody and human complement increased the formation of C3a and C5a. Monocyte recruitment by human HLA antibodies was enhanced in the presence of intact human serum complement or purified C3a or C5a. Specific inhibition of the classical complement pathway using TNT003 or C1q-depleted serum significantly reduced adhesion of monocytes in the presence of human complement. Conclusions Despite persistent endothelial viability in the presence of HLA antibodies and complement, upstream complement anaphylatoxin production exacerbates endothelial exocytosis and leukocyte recruitment. Upstream inhibition of classical complement may be therapeutic to dampen mononuclear cell recruitment and endothelial activation characteristic of microvascular inflammation during AMR. PMID:28640789

Monocyte-mediated delivery of polymeric backpacks to inflamed tissues: a generalized strategy to deliver drugs to treat inflammation.

PubMed

Anselmo, Aaron C; Gilbert, Jonathan B; Kumar, Sunny; Gupta, Vivek; Cohen, Robert E; Rubner, Michael F; Mitragotri, Samir

2015-02-10

Targeted delivery of drugs and imaging agents to inflamed tissues, as in the cases of cancer, Alzheimer's disease, Parkinson's disease, and arthritis, represents one of the major challenges in drug delivery. Monocytes possess a unique ability to target and penetrate into sites of inflammation. Here, we describe a broad approach to take advantage of the natural ability of monocytes to target and deliver flat polymeric particles ("Cellular Backpacks") to inflamed tissues. Cellular backpacks attach strongly to the surface of monocytes but do not undergo phagocytosis due to backpack's size, disk-like shape and flexibility. Following attachment of backpacks, monocytes retain important cellular functions including transmigration through an endothelial monolayer and differentiation into macrophages. In two separate in vivo inflammation models, backpack-laden monocytes exhibit increased targeting to inflamed tissues. Cellular backpacks, and their abilities to attach to monocytes without impairing monocyte functions and 'hitchhike' to a variety of inflamed tissues, offer a new platform for both cell-mediated therapies and broad targeting of inflamed tissues. Copyright © 2014 Elsevier B.V. All rights reserved.

Galectin-3 expression in response to LPS, immunomodulatory drugs and exogenously added galectin-3 in monocyte-like THP-1 cells.

PubMed

Dabelic, Sanja; Novak, Ruder; Goreta, Sandra Supraha; Dumic, Jerka

2012-09-01

Galectin-3, a structurally unique beta-galactoside-binding lectin, through the specific protein-protein and protein-carbohydrate interactions participates in numerous biological processes, such as cell proliferation and apoptosis, adhesion and activation. Its expression and secretion by until now an unknown mechanism are modulated by diverse molecules and are dependent on different physiological and pathophysiological conditions. By autocrine and paracrine actions, galectin-3 modulates many immune reactions and affects various immune cells, particularly those of monocyte-macrophage lineage. This is why galectin-3 has recently become an attractive therapeutic target. However, molecular mechanisms of its actions as well as regulatory mechanism of its expression and activation are still largely unknown. In this study, we show that lipopolysaccharide (LPS) provokes upregulation of galectin-3 expression on both gene and protein level in monocyte-like THP-1 cells, which can be inhibited by dexamethasone, but not with non-steroidal anti-inflammatory drugs aspirin and indomethacin. Resting and LPS-challenged monocyte-like THP-1 cells do not have detectable amount of surface-bound galectin-3, but are able to bind exogenously added galectin-3 with the same capacity. Although galectin-3 is generally considered to be a pro-inflammatory molecule, here we show that the exogenously added galectin-3 does not affect interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α production in resting and LPS-activated monocyte-like THP-1 cells nor influences its own gene expression level in those cells.

Tracking the Spatial and Functional Gradient of Monocyte-To-Macrophage Differentiation in Inflamed Lung.

PubMed

Sen, Debasish; Jones, Stephen M; Oswald, Erin M; Pinkard, Henry; Corbin, Kaitlin; Krummel, Matthew F

2016-01-01

Myeloid-derived cells such as monocytes, dendritic cells (DCs), and macrophages are at the heart of the immune effector function in an inflammatory response. But because of the lack of an efficient imaging system to trace these cells live during their migration and maturation in their native environment at sub-cellular resolution, our knowledge is limited to data available from specific time-points analyzed by flow cytometry, histology, genomics and other immunological methods. Here, we have developed a ratiometric imaging method for measuring monocyte maturation in inflamed mouse lungs in situ using real-time using 2-photon imaging and complementary methods. We visualized that while undifferentiated monocytes were predominantly found only in the vasculature, a semi-differentiated monocyte/macrophage population could enter the tissue and resembled more mature and differentiated populations by morphology and surface phenotype. As these cells entered and differentiated, they were already selectively localized near inflamed airways and their entry was associated with changes in motility and morphology. We were able to visualize these during the act of differentiation, a process that can be demonstrated in this way to be faster on a per-cell basis under inflammatory conditions. Finally, our in situ analyses demonstrated increases, in the differentiating cells, for both antigen uptake and the ability to mediate interactions with T cells. This work, while largely confirming proposed models for in situ differentiation, provides important in situ data on the coordinated site-specific recruitment and differentiation of these cells and helps elaborate the predominance of immune pathology at the airways. Our novel imaging technology to trace immunogenic cell maturation in situ will complement existing information available on in situ differentiation deduced from other immunological methods, and assist better understanding of the spatio-temporal cellular behavior during an inflammatory response.

Characterization of synthetic lung surfactant activity against proinflammatory cytokines in human monocytes.

PubMed

Otsubo, Eiji; Irimajiri, Kiyohiro; Takei, Tsunetomo; Nomura, Masato

2002-03-01

Our previous study demonstrated that the smallest synthetic peptide with the sequence CPVHLKRLLLLLLLLLLLLLLLL, SP-CL16(6-28), admixed with phospholipid (synthetic lung surfactant, SLS) showed strong surface activity. In this study, we attempted to develop a dual-type surfactant with both anti inflammatory and surface activities. SP-CL16(6-28) was first chemically synthesized and then purified for use by centrifugal partition chromatography. A mixture of SP-CL16(6-28) and phospholipid complex was tested for anti inflammatory activity using the human monocyte cell line THP-1. Whether the suppression of tumor necrosis factor-alpha (TNF-a), interleukin (IL)-8, IL-6, IL-1beta, and macrophage migration inhibitory factor (MIF) was reduced by lipopolysaccharide (LPS) in monocytes was examined. Levels of these cytokines were measured by enzyme-linked immunosorbent assay. It was found that SLS significantly and dose dependently inhibited the secretion of TNF-alpha by THP-1 cells following stimulation with LPS. Dipalmitoylphosphatidylcoline did not inhibit the release of cytokines. These findings suggest that SLS has anti inflammatory activity. Therefore it should be possible to develop a SLS with both anti inflammatory activity and surface activity.

A positive feedback loop between IL-1β, LPS and NEU1 may promote atherosclerosis by enhancing a pro-inflammatory state in monocytes and macrophages.

PubMed

Sieve, Irina; Ricke-Hoch, Melanie; Kasten, Martina; Battmer, Karin; Stapel, Britta; Falk, Christine S; Leisegang, Matthias S; Haverich, Axel; Scherr, Michaela; Hilfiker-Kleiner, Denise

2018-04-01

Inflammation plays an important role in atherosclerosis, a notion supported by the beneficial effects of the IL-1β inhibitor canakinumab in the CANTOS trial. Sialic acids (Sias), components of the surface glycocalyx, regulate intercellular and intermolecular interactions. We investigated the expression of the Sia cleaving enzyme neuraminidase-1 (NEU1) in atherosclerotic plaques and its potential role in inflammatory processes. In isolated mononuclear blood cells from patients with myocardial infarction, NEU1 expression was increased compared to healthy controls. High expression of NEU1 in macrophages located on the intima layer, in calcified regions and the adventitia of the plaque was observed in human carotid arteries' atherectomies. IL-1β and LPS induced NEU1 expression in THP-1 monocytic cells. Lentiviral NEU1-overexpression in THP-1-cells enhanced expression of CD80, TNF-α, IL-1β, number of multinuclear cells, phagocytosis and chemotaxis indicative for M1 monocyte/macrophage polarization. CRISPR/Cas9-mediated knock-out of NEU1 in THP-1-cells did not affect differentiation of monocytes to macrophages but attenuated LPS- and IL-1β -induced TNF-α and IL-1β expression. SiRNA-mediated knock-down of NEU1 in M1-macrophages differentiated from primary human CD14 + monocytes reduced the expression of TNF-α and IL-1β. Thus, in monocytes/macrophages, LPS, NEU1 and IL-1β act in a positive feedback loop as enhancers of inflammation and may therefore promote atherosclerosis and plaque instability. Copyright © 2018 Elsevier Inc. All rights reserved.

Visualization of T Cell-Regulated Monocyte Clusters Mediating Keratinocyte Death in Acquired Cutaneous Immunity.

PubMed

Liu, Zheng; Yang, Fei; Zheng, Hao; Fan, Zhan; Qiao, Sha; Liu, Lei; Tao, Juan; Luo, Qingming; Zhang, Zhihong

2018-06-01

It remains unclear how monocytes are mobilized to amplify inflammatory reactions in T cell-mediated adaptive immunity. Here, we investigate dynamic cellular events in the cascade of inflammatory responses through intravital imaging of a multicolor-labeled murine contact hypersensitivity model. We found that monocytes formed clusters around hair follicles in the contact hypersensitivity model. In this process, effector T cells encountered dendritic cells under regions of monocyte clusters and secreted IFN-γ, which mobilizes CCR2-dependent monocyte interstitial migration and CXCR2-dependent monocyte cluster formation. We showed that hair follicles shaped the inflammatory microenvironment for communication among the monocytes, keratinocytes, and effector T cells. After disrupting the T cell-mobilized monocyte clusters through CXCR2 antagonization, monocyte activation and keratinocyte apoptosis were significantly inhibited. Our study provides a new perspective on effector T cell-regulated monocyte behavior, which amplifies the inflammatory reaction in acquired cutaneous immunity. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Insights into deregulated TNF and IL-10 production in malaria: implications for understanding severe malarial anaemia.

PubMed

Boeuf, Philippe S; Loizon, Séverine; Awandare, Gordon A; Tetteh, John K A; Addae, Michael M; Adjei, George O; Goka, Bamenla; Kurtzhals, Jørgen A L; Puijalon, Odile; Hviid, Lars; Akanmori, Bartholomew D; Behr, Charlotte

2012-08-01

Severe malarial anaemia (SMA) is a major life-threatening complication of paediatric malaria. Protracted production of pro-inflammatory cytokines promoting erythrophagocytosis and depressing erythropoiesis is thought to play an important role in SMA, which is characterized by a high TNF/IL-10 ratio. Whether this TNF/IL-10 imbalance results from an intrinsic incapacity of SMA patients to produce IL-10 or from an IL-10 unresponsiveness to infection is unknown. Monocytes and T cells are recognized as the main sources of TNF and IL-10 in vivo, but little is known about the activation status of those cells in SMA patients. The IL-10 and TNF production capacity and the activation phenotype of monocytes and T cells were compared in samples collected from 332 Ghanaian children with non-overlapping SMA (n = 108), cerebral malaria (CM) (n = 144) or uncomplicated malaria (UM) (n = 80) syndromes. Activation status of monocytes and T cells was ascertained by measuring HLA-DR+ and/or CD69+ surface expression by flow cytometry. The TNF and IL-10 production was assessed in a whole-blood assay after or not stimulation with lipopolysaccharide (LPS) or phytohaemaglutinin (PHA) used as surrogate of unspecific monocyte and T cell stimulant. The number of circulating pigmented monocytes was also determined. Monocytes and T cells from SMA and CM patients showed similar activation profiles with a comparable decreased HLA-DR expression on monocytes and increased frequency of CD69+ and HLA-DR+ T cells. In contrast, the acute-phase IL-10 production was markedly decreased in SMA compared to CM (P = .003) and UM (P = .004). Although in SMA the IL-10 response to LPS-stimulation was larger in amplitude than in CM (P = .0082), the absolute levels of IL-10 reached were lower (P = .013). Both the amplitude and levels of TNF produced in response to LPS-stimulation were larger in SMA than CM (P = .019). In response to PHA-stimulation, absolute levels of IL-10 produced in SMA were lower than in CM (P = .005) contrasting with TNF levels, which were higher (P = .001). These data reveal that SMA patients have the potential to mount efficient IL-10 responses and that the TNF/IL-10 imbalance may reflect a specific monocyte and T cell programming/polarization pattern in response to infection.

The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur

PubMed Central

Kim, Su-Han; Ko, Hyun-Chang; Kwon, Kyung-Sool; Oh, Chang-Keun

2009-01-01

Background Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-α, IL-6 and IL-1β in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. Objective We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Methods Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. Results The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-α were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). Conclusion According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done. PMID:20523770

Calcium-Binding Proteins S100A8 and S100A9: Investigation of Their Immune Regulatory Effect in Myeloid Cells.

PubMed

Yang, Jianxin; Anholts, Jacqueline; Kolbe, Ulrike; Stegehuis-Kamp, Janine A; Claas, Frans H J; Eikmans, Michael

2018-06-21

High expression levels of the calcium-binding proteins S100A8 and S100A9 in myeloid cells in kidney transplant rejections are associated with a favorable outcome. Here we investigated the myeloid cell subset expressing these molecules, and their function in inflammatory reactions. Different monocyte subsets were sorted from buffy coats of healthy donors and investigated for S100A8 and S100A9 expression. To characterize S100A9high and S100A9low subsets within the CD14+ classical monocyte subset, intracellular S100A9 staining was combined with flow cytometry (FACS) and qPCR profiling. Furthermore, S100A8 and S100A9 were overexpressed by transfection in primary monocyte-derived macrophages and the THP-1 macrophage cell line to investigate the functional relevance. Expression of S100A8 and S100A9 was primarily found in classical monocytes and to a much lower extent in intermediate and non-classical monocytes. All S100A9+ cells expressed human leukocyte antigen—antigen D related (HLA-DR) on their surface. A small population (<3%) of CD14+ CD11b+ CD33+ HLA-DR− cells, characterized as myeloid derived suppressor cells (MDSCs), also expressed S100A9 to high extent. Overexpression of S100A8 and S00A9 in macrophages led to enhanced extracellular reactive oxygen species (ROS) production, as well as elevated mRNA expression of anti-inflammatory IL-10 . The results suggest that the calcium-binding proteins S100A8 and S100A9 in myeloid cells have an immune regulatory effect.

Modulation of tumor necrosis factor (TNF) receptor expression during monocytic differentiation by glucocorticoids.

PubMed

Goppelt-Struebe, M; Reiser, C O; Schneider, N; Grell, M

1996-10-01

Regulation of tumor necrosis factor receptors by glucocorticoids was investigated during phorbol ester-induced monocytic differentiation. As model system the human monocytic cell lines U937 and THP-1, which express both types of TNF receptors (TNF-R60 and TNF-R80), were differentiated with tetradecanoyl phorbol-13-acetate (TPA, 5 x 10(-9) M) in the presence or absence of dexamethasone (10(-9) - 10(-6) M). Expression of TNF receptors was determined at the mRNA level by Northern blot analysis and at the protein level by FACS analysis. During differentiation, TNF-R60 mRNA was down-regulated, whereas TNF-R80 mRNA levels were increased. Dexamethasone had no effect on TNF-R60 mRNA expression but attenuated TNF-R80 mRNA expression in both cell lines. Cell surface expression of TNF-R60 protein remained essentially unchanged during differentiation of THP-1 cells, whereas a rapid down-regulation of TNF-R80 was observed that was followed by a slow recovery. Surface expression of TNF-R80 was not affected by dexamethasone, whereas TNF-R60 expression was reduced by about 25%. These results indicate differential regulation of the two types of TNF receptors at the mRNA and protein level during monocytic differentiation. Glucocorticoids interfered with mRNA expression of TNF-R80 and protein expression of TNF-R60, but the rather limited effect leaves the question of its functional relevance open. In contrast to other cytokine systems, TNF receptors do not appear to be major targets of glucocorticoid action.

Monoclonal antibodies to the equine CD2 T lymphocyte marker, to a pan-granulocyte/monocyte marker and to a unique pan-B lymphocyte marker.

PubMed

Tumas, D B; Brassfield, A L; Travenor, A S; Hines, M T; Davis, W C; McGuire, T C

1994-12-01

Murine monoclonal antibodies, HB88A, B29A and DH59B separately identify the CD2 T lymphocyte molecule, a unique pan-B lymphocyte surface marker and a pan-granulocyte/monocyte surface molecule, respectively, in the horse. Specificity was shown by two-color immunofluorescent flow cytometry and immunofluorescent microscopy. MAb HB88A reacted with a 52 kDa pan-T lymphocyte molecule present on 75% +/- 7 of peripheral blood lymphocytes (PBL) (n = 15 horses). It also reacted with lymphocytes restricted to T lymphocyte dependent areas of lymph node and spleen. Specificity of mAb HB88A to CD2 was demonstrated by its reactivity to COS7 cells which expressed a transfected 1.5 kb equine lymphocyte c-DNA clone having 77.5% overall sequence homology with human CD2 c-DNA. MAb B29A reacted with a pan-B lymphocyte specific cell surface complex, 143, 72, 50, 40, 27 and 14.5 kDa, present on 19% +/- 7 of PBL (n = 15 horses). This complex has not been described in the horse or other species. MAb DH59B reacted with a 96 kDa pan-granulocyte/monocyte specific surface protein and identified macrophages and Kupffer cells in equine tissue sections. Together these mAbs can be used to identify and quantitate the major constituents of equine leukocytes.

Antiviral Regulation in Porcine Monocytic Cells at Different Activation States

PubMed Central

Rowland, Raymond R. R.

2014-01-01

ABSTRACT Monocytic cells, including macrophages and dendritic cells, exist in different activation states that are critical to the regulation of antimicrobial immunity. Many pandemic viruses are monocytotropic, including porcine reproductive and respiratory syndrome virus (PRRSV), which directly infects subsets of monocytic cells and interferes with antiviral responses. To study antiviral responses in PRRSV-infected monocytic cells, we characterized inflammatory cytokine responses and genome-wide profiled signature genes to investigate response pathways in uninfected and PRRSV-infected monocytic cells at different activation states. Our findings showed suppressed interferon (IFN) production in macrophages in non-antiviral states and an arrest of lipid metabolic pathways in macrophages at antiviral states. Importantly, porcine monocytic cells at different activation states were susceptible to PRRSV and responded differently to viral infection. Based on Gene Ontology (GO) analysis, two approaches were used to potentiate antiviral activity: (i) pharmaceutical modulation of cellular lipid metabolism and (ii) in situ PRRSV replication-competent expression of interferon alpha (IFN-α). Both approaches significantly suppressed exogenous viral infection in monocytic cells. In particular, the engineered IFN-expressing PRRSV strain eliminated exogenous virus infection and sustained cell viability at 4 days postinfection in macrophages. These findings suggest an intricate interaction of viral infection with the activation status of porcine monocytic cells. An understanding and integration of antiviral infection with activation status of monocytic cells may provide a means of potentiating antiviral immunity. IMPORTANCE Activation statuses of monocytic cells, including monocytes, macrophages (Mϕs), and dendritic cells (DCs), are critically important for antiviral immunity. Unfortunately, the activation status of porcine monocytic cells or how cell activation status functionally interacts with antiviral immunity remains largely unknown. This is a significant omission because many economically important porcine viruses are monocytotropic, including our focus, PRRSV, which alone causes nearly $800 million economic loss annually in the U.S. swine industries. PRRSV is ideal for deciphering how monocytic cell activation statuses interact with antiviral immunity, because it directly infects subsets of monocytic cells and subverts overall immune responses. In this study, we systematically investigate the activation status of porcine monocytic cells to determine the intricate interaction of viral infection with activation statuses and functionally regulate antiviral immunity within the framework of the activation paradigm. Our findings may provide a means of potentiating antiviral immunity and leading to novel vaccines for PRRS prevention. PMID:25056886

The effects of monocytes on tumor cell extravasation in a 3D vascularized microfluidic model.

PubMed

Boussommier-Calleja, A; Atiyas, Y; Haase, K; Headley, M; Lewis, C; Kamm, R D

2018-03-05

Metastasis is the leading cause of cancer-related deaths. Recent developments in cancer immunotherapy have shown exciting therapeutic promise for metastatic patients. While most therapies target T cells, other immune cells, such as monocytes, hold great promise for therapeutic intervention. In our study, we provide primary evidence of direct engagement between human monocytes and tumor cells in a 3D vascularized microfluidic model. We first characterize the novel application of our model to investigate and visualize at high resolution the evolution of monocytes as they migrate from the intravascular to the extravascular micro-environment. We also demonstrate their differentiation into macrophages in our all-human model. Our model replicates physiological differences between different monocyte subsets. In particular, we report that inflammatory, but not patrolling, monocytes rely on actomyosin based motility. Finally, we exploit this platform to study the effect of monocytes, at different stages of their life cycle, on cancer cell extravasation. Our data demonstrates that monocytes can directly reduce cancer cell extravasation in a non-contact dependent manner. In contrast, we see little effect of monocytes on cancer cell extravasation once monocytes transmigrate through the vasculature and are macrophage-like. Taken together, our study brings novel insight into the role of monocytes in cancer cell extravasation, which is an important step in the metastatic cascade. These findings establish our microfluidic platform as a powerful tool to investigate the characteristics and function of monocytes and monocyte-derived macrophages in normal and diseased states. We propose that monocyte-cancer cell interactions could be targeted to potentiate the anti-metastatic effect we observe in vitro, possibly expanding the milieu of immunotherapies available to tame metastasis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Regulation of monocyte cell fate by blood vessels mediated by Notch signalling.

PubMed

Gamrekelashvili, Jaba; Giagnorio, Roberto; Jussofie, Jasmin; Soehnlein, Oliver; Duchene, Johan; Briseño, Carlos G; Ramasamy, Saravana K; Krishnasamy, Kashyap; Limbourg, Anne; Kapanadze, Tamar; Ishifune, Chieko; Hinkel, Rabea; Radtke, Freddy; Strobl, Lothar J; Zimber-Strobl, Ursula; Napp, L Christian; Bauersachs, Johann; Haller, Hermann; Yasutomo, Koji; Kupatt, Christian; Murphy, Kenneth M; Adams, Ralf H; Weber, Christian; Limbourg, Florian P

2016-08-31

A population of monocytes, known as Ly6C(lo) monocytes, patrol blood vessels by crawling along the vascular endothelium. Here we show that endothelial cells control their origin through Notch signalling. Using combinations of conditional genetic deletion strategies and cell-fate tracking experiments we show that Notch2 regulates conversion of Ly6C(hi) monocytes into Ly6C(lo) monocytes in vivo and in vitro, thereby regulating monocyte cell fate under steady-state conditions. This process is controlled by Notch ligand delta-like 1 (Dll1) expressed by a population of endothelial cells that constitute distinct vascular niches in the bone marrow and spleen in vivo, while culture on recombinant DLL1 induces monocyte conversion in vitro. Thus, blood vessels regulate monocyte conversion, a form of committed myeloid cell fate regulation.

Regulation of monocyte cell fate by blood vessels mediated by Notch signalling

PubMed Central

Gamrekelashvili, Jaba; Giagnorio, Roberto; Jussofie, Jasmin; Soehnlein, Oliver; Duchene, Johan; Briseño, Carlos G.; Ramasamy, Saravana K.; Krishnasamy, Kashyap; Limbourg, Anne; Häger, Christine; Kapanadze, Tamar; Ishifune, Chieko; Hinkel, Rabea; Radtke, Freddy; Strobl, Lothar J.; Zimber-Strobl, Ursula; Napp, L. Christian; Bauersachs, Johann; Haller, Hermann; Yasutomo, Koji; Kupatt, Christian; Murphy, Kenneth M.; Adams, Ralf H.; Weber, Christian; Limbourg, Florian P.

2016-01-01

A population of monocytes, known as Ly6Clo monocytes, patrol blood vessels by crawling along the vascular endothelium. Here we show that endothelial cells control their origin through Notch signalling. Using combinations of conditional genetic deletion strategies and cell-fate tracking experiments we show that Notch2 regulates conversion of Ly6Chi monocytes into Ly6Clo monocytes in vivo and in vitro, thereby regulating monocyte cell fate under steady-state conditions. This process is controlled by Notch ligand delta-like 1 (Dll1) expressed by a population of endothelial cells that constitute distinct vascular niches in the bone marrow and spleen in vivo, while culture on recombinant DLL1 induces monocyte conversion in vitro. Thus, blood vessels regulate monocyte conversion, a form of committed myeloid cell fate regulation. PMID:27576369

Immunomodulatory properties of carbon nanotubes are able to compensate immune function dysregulation caused by microgravity conditions

NASA Astrophysics Data System (ADS)

Crescio, Claudia; Orecchioni, Marco; Ménard-Moyon, Cécilia; Sgarrella, Francesco; Pippia, Proto; Manetti, Roberto; Bianco, Alberto; Delogu, Lucia Gemma

2014-07-01

Spaceflights lead to dysregulation of the immune cell functionality affecting the expression of activation markers and cytokine production. Short oxidized multi-walled carbon nanotubes functionalized by 1,3-dipolar cycloaddition have been reported to activate immune cells. In this Communication we have performed surface marker assays and multiplex ELISA on primary monocytes and T cells under microgravity. We have discovered that carbon nanotubes, through their immunostimulatory properties, are able to fight spaceflight immune system dysregulations.Spaceflights lead to dysregulation of the immune cell functionality affecting the expression of activation markers and cytokine production. Short oxidized multi-walled carbon nanotubes functionalized by 1,3-dipolar cycloaddition have been reported to activate immune cells. In this Communication we have performed surface marker assays and multiplex ELISA on primary monocytes and T cells under microgravity. We have discovered that carbon nanotubes, through their immunostimulatory properties, are able to fight spaceflight immune system dysregulations. Electronic supplementary information (ESI) available: Experimental section, structures of f-MWCNTs and uptake by human primary immune cells. See DOI: 10.1039/c4nr02711f

Robust and Highly-Efficient Differentiation of Functional Monocytic Cells from Human Pluripotent Stem Cells under Serum- and Feeder Cell-Free Conditions

PubMed Central

Yanagimachi, Masakatsu D.; Niwa, Akira; Tanaka, Takayuki; Honda-Ozaki, Fumiko; Nishimoto, Seiko; Murata, Yuuki; Yasumi, Takahiro; Ito, Jun; Tomida, Shota; Oshima, Koichi; Asaka, Isao; Goto, Hiroaki; Heike, Toshio; Nakahata, Tatsutoshi; Saito, Megumu K.

2013-01-01

Monocytic lineage cells (monocytes, macrophages and dendritic cells) play important roles in immune responses and are involved in various pathological conditions. The development of monocytic cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is of particular interest because it provides an unlimited cell source for clinical application and basic research on disease pathology. Although the methods for monocytic cell differentiation from ESCs/iPSCs using embryonic body or feeder co-culture systems have already been established, these methods depend on the use of xenogeneic materials and, therefore, have a relatively poor-reproducibility. Here, we established a robust and highly-efficient method to differentiate functional monocytic cells from ESCs/iPSCs under serum- and feeder cell-free conditions. This method produced 1.3×106±0.3×106 floating monocytes from approximately 30 clusters of ESCs/iPSCs 5–6 times per course of differentiation. Such monocytes could be differentiated into functional macrophages and dendritic cells. This method should be useful for regenerative medicine, disease-specific iPSC studies and drug discovery. PMID:23573196

Evaluation of suppressive and pro-resolving effects of EPA and DHA in human primary monocytes and T-helper cells[S

PubMed Central

Jaudszus, Anke; Gruen, Michael; Watzl, Bernhard; Ness, Christina; Roth, Alexander; Lochner, Alfred; Barz, Dagmar; Gabriel, Holger; Rothe, Michael; Jahreis, Gerhard

2013-01-01

Despite their beneficial anti-inflammatory properties, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may increase the infection risk at high doses, likely by generating an immune-depressed state. To assess the contribution of different immune cell populations to the immunomodulatory fatty acid effect, we comparatively investigated several aspects of inflammation in human T-helper (Th) cells and monocytes. Both fatty acids, but DHA to a lesser extent compared with EPA, selectively and dose-dependently reduced the percentage of cytokine-expressing Th cells in a peroxisome proliferator-activated receptor (PPAR)γ-dependent fashion, whereas the expression of the cell surface marker CD69 was unaltered on activated T cells. In monocytes, both EPA and DHA increased interleukin (IL)-10 without affecting tumor necrosis factor (TNF)-α and IL-6. Cellular incorporation of EPA and DHA occurred mainly at the expense of arachidonic acid. Concomitantly, thromboxane B (TXB)2 and leukotriene B (LTB)4 in supernatants decreased, while levels of TXB3 and LTB5 increased. This increase was independent of activation and in accordance with cyclooxygenase expression patterns in monocytes. Moreover, EPA and DHA gave rise to a variety of mono- and trihydroxy derivatives of highly anti-inflammatory potential, such as resolvins and their precursors. Our results suggest that EPA and DHA do not generally affect immune cell functions in an inhibitory manner but rather promote pro-resolving responses. PMID:23349208

7α-Hydroxycholesterol Elicits TLR6-Mediated Expression of IL-23 in Monocytic Cells.

PubMed

Seo, Hyun Chul; Kim, Sun-Mi; Eo, Seong-Kug; Rhim, Byung-Yong; Kim, Koanhoi

2015-01-01

We investigated the question of whether 7-oxygenated cholesterol derivatives could affect inflammatory and/or immune responses in atherosclerosis by examining their effects on expression of IL-23 in monocytic cells. 7α-Hydroxycholesterol (7αOHChol) induced transcription of the TLR6 gene and elevated the level of cell surface TLR6 protein in THP-1 monocytic cells. Addition of an agonist of TLR6, FSL-1, to TLR6-expressing cells by treatment with 7αOHChol resulted in enhanced production of IL-23 and transcription of genes encoding the IL-23 subunit α (p19) and the IL-12 subunit β (p40). However, treatment with 7-ketocholesterol (7K) and 7β-hydroxycholesterol (7βOHChol) did not affect TLR6 expression, and addition of FSL-1 to cells treated with either 7K or 7βOHChol did not influence transcription of the genes. Pharmacological inhibition of ERK, Akt, or PI3K resulted in attenuated transcription of TLR6 induced by 7αOHChol as well as secretion of IL-23 enhanced by 7αOHChol plus FSL-1. Inhibition of p38 MAPK or JNK resulted in attenuated secretion of IL-23. These results indicate that a certain type of 7-oxygenated cholesterol like 7αOHChol can elicit TLR6-mediated expression of IL-23 by monocytic cells via PI3K/Akt and MAPKs pathways.

7α-Hydroxycholesterol Elicits TLR6-Mediated Expression of IL-23 in Monocytic Cells

PubMed Central

Seo, Hyun Chul; Kim, Sun-Mi; Eo, Seong-Kug; Rhim, Byung-Yong; Kim, Koanhoi

2015-01-01

We investigated the question of whether 7-oxygenated cholesterol derivatives could affect inflammatory and/or immune responses in atherosclerosis by examining their effects on expression of IL-23 in monocytic cells. 7α-Hydroxycholesterol (7αOHChol) induced transcription of the TLR6 gene and elevated the level of cell surface TLR6 protein in THP-1 monocytic cells. Addition of an agonist of TLR6, FSL-1, to TLR6-expressing cells by treatment with 7αOHChol resulted in enhanced production of IL-23 and transcription of genes encoding the IL-23 subunit α (p19) and the IL-12 subunit β (p40). However, treatment with 7-ketocholesterol (7K) and 7β-hydroxycholesterol (7βOHChol) did not affect TLR6 expression, and addition of FSL-1 to cells treated with either 7K or 7βOHChol did not influence transcription of the genes. Pharmacological inhibition of ERK, Akt, or PI3K resulted in attenuated transcription of TLR6 induced by 7αOHChol as well as secretion of IL-23 enhanced by 7αOHChol plus FSL-1. Inhibition of p38 MAPK or JNK resulted in attenuated secretion of IL-23. These results indicate that a certain type of 7-oxygenated cholesterol like 7αOHChol can elicit TLR6-mediated expression of IL-23 by monocytic cells via PI3K/Akt and MAPKs pathways. PMID:25593648

An in vitro monocyte culture method and establishment of a human monocytic cell line (K63).

PubMed

Kadoi, Katsuyuki

2011-01-01

A novel method of monocyte culture in vitro was developed. The fraction of monocytes was obtained by density centrifugation of heparinised human venous blood samples. Monocytes were suspended in a modified Rosewell Park Memorial Institute medium (RPMI)-1640 (mRPMI) supplemented with 10% non-inactivated autologous serum added to the feeder cells. An avian cell line was used for feeder cells. Only those monocytes that settled on feeder cells grew rapidly at 37°C-38°C into a formation of clumped masses within two to three days. The cell mass was harvested and subcultures were made without feeder cells. A stable cell line (K63) was established from subcultures using a limited dilution method and cell cloning in microplates. K63 cells were adapted for later growth in the mRPMI medium supplemented with 10% foetal calf serum. The cells were well maintained at over 50th passage levels. This method proved to be applicable for monocyte cultures of animals as well.

Improved Cognitive Performance and Reduced Monocyte Activation in Virally Suppressed Chronic HIV Following Dual CCR2 and CCR5 Antagonism.

PubMed

D'Antoni, Michelle L; Paul, Robert H; Mitchell, Brooks I; Kohorn, Lindsay; Fischer, Laurent; Lefebvre, Eric; Seyedkazemi, Star; Nakamoto, Beau K; Walker, Maegen; Kallianpur, Kalpana J; Ogata-Arakaki, Debra; Ndhlovu, Lishomwa C; Shikuma, Cecilia

2018-05-16

To evaluate changes in neuropsychological (NP) performance and in plasma and cell surface markers of peripheral monocyte activation/migration following treatment with cenicriviroc (CVC), a dual C-C chemokine receptor type 2 (CCR2) and type 5 (CCR5) antagonist, in treatment-experienced, HIV-infected individuals. Single-arm, 24-week, open-label clinical trial. HIV-infected individuals on antiretroviral therapy (ART) >1 year with plasma HIV RNA <50 copies/ml and below-normal cognitive performance [defined as age, gender and education-adjusted NP performance (NPZ) <-0.5 in a single cognitive domain or in global performance] were enrolled. Changes over 24 weeks were assessed for global and domain-specific NPZ scores, plasma markers of monocyte/macrophage activation [neopterin, soluble (s)CD14 and sCD163] quantified by ELISA, and CCR2 and CCR5 expression on monocytes and T cells measured by flow cytometry. Seventeen of 20 enrolled participants completed the study. Improvements over 24 weeks were observed in global NPZ [median change (Δ)=0.24; p=0.008], and in cognitive domains of attention (Δ0.23; p=0.011) and working memory (Δ0.44; p=0.017). Plasma levels of sCD163, sCD14, and neopterin decreased significantly (p's<0.01). CCR2 and CCR5 monocyte expression remained unchanged; however, CCR5 levels on CD4 and CD8 T cells and CCR2 expression on CD4 T cells increased (p's<0.01). CVC given over 24 weeks was associated with improved NP test performance and decreased plasma markers of monocyte immune activation in virally-suppressed, HIV-infected participants. These data potentially link changes in monocyte activation to cognitive performance. Further study of CVC for HIV cognitive impairment in a randomized controlled study is warranted.

Mesenchymal Stem/Multipotent Stromal Cells from Human Decidua Basalis Reduce Endothelial Cell Activation.

PubMed

Alshabibi, Manal A; Al Huqail, Al Joharah; Khatlani, Tanvir; Abomaray, Fawaz M; Alaskar, Ahmed S; Alawad, Abdullah O; Kalionis, Bill; Abumaree, Mohamed Hassan

2017-09-15

Recently, we reported the isolation and characterization of mesenchymal stem cells from the decidua basalis of human placenta (DBMSCs). These cells express a unique combination of molecules involved in many important cellular functions, which make them good candidates for cell-based therapies. The endothelium is a highly specialized, metabolically active interface between blood and the underlying tissues. Inflammatory factors stimulate the endothelium to undergo a change to a proinflammatory and procoagulant state (ie, endothelial cell activation). An initial response to endothelial cell activation is monocyte adhesion. Activation typically involves increased proliferation and enhanced expression of adhesion and inflammatory markers by endothelial cells. Sustained endothelial cell activation leads to a type of damage to the body associated with inflammatory diseases, such as atherosclerosis. In this study, we examined the ability of DBMSCs to protect endothelial cells from activation through monocyte adhesion, by modulating endothelial proliferation, migration, adhesion, and inflammatory marker expression. Endothelial cells were cocultured with DBMSCs, monocytes, monocyte-pretreated with DBMSCs and DBMSC-pretreated with monocytes were also evaluated. Monocyte adhesion to endothelial cells was examined following treatment with DBMSCs. Expression of endothelial cell adhesion and inflammatory markers was also analyzed. The interaction between DBMSCs and monocytes reduced endothelial cell proliferation and monocyte adhesion to endothelial cells. In contrast, endothelial cell migration increased in response to DBMSCs and monocytes. Endothelial cell expression of adhesion and inflammatory molecules was reduced by DBMSCs and DBMSC-pretreated with monocytes. The mechanism of reduced endothelial proliferation involved enhanced phosphorylation of the tumor suppressor protein p53. Our study shows for the first time that DBMSCs protect endothelial cells from activation by inflammation triggered by monocyte adhesion and increased endothelial cell proliferation. These events are manifest in inflammatory diseases, such as atherosclerosis. Therefore, our results suggest that DBMSCs could be usefully employed as a therapeutic strategy for atherosclerosis.

Plasmacytoid monocytes in epithelioid cell granulomas: ultrastructural and immunoelectron microscopic study.

PubMed

De Vos, R; De Wolf-Peeters, C; Facchetti, F; Desmet, V

1990-01-01

Plasmacytoid monocytes, the so-called plasmacytoid T cells, were originally described in rare cases of lymphadenitis. Recent immunohistochemical studies have demonstrated their monocytic origin. Plasmacytoid monocytes have in common with epithelioid cells and multinucleated giant cells the expression of several antigens; they also occur in close topographic association with epithelioid and multinucleated giant cells in epithelioid cell granulomas. On the basis of these data it has been suggested that plasmacytoid monocytes may transform into epithelioid cells. The present ultrastructural and immunoelectron microscopic study of epithelioid cell granulomas provides further arguments in favor of this hypothesis. Moreover, the existence of a transitional cell type with characteristics of plasmacytoid monocytes and epithelioid cells is documented. Subplasmalemmal linear densities present on focal areas of the plasma membrane of the main cell components of granulomas are also discussed.

Comparative genotypic and phenotypic analysis of human peripheral blood monocytes and surrogate monocyte-like cell lines commonly used in metabolic disease research.

PubMed

Riddy, Darren M; Goy, Emily; Delerive, Philippe; Summers, Roger J; Sexton, Patrick M; Langmead, Christopher J

2018-01-01

Monocyte-like cell lines (MCLCs), including THP-1, HL-60 and U-937 cells, are used routinely as surrogates for isolated human peripheral blood mononuclear cells (PBMCs). To systematically evaluate these immortalised cells and PBMCs as model systems to study inflammation relevant to the pathogenesis of type II diabetes and immuno-metabolism, we compared mRNA expression of inflammation-relevant genes, cell surface expression of cluster of differentiation (CD) markers, and chemotactic responses to inflammatory stimuli. Messenger RNA expression analysis suggested most genes were present at similar levels across all undifferentiated cells, though notably, IDO1, which encodes for indoleamine 2,3-dioxygenase and catabolises tryptophan to kynureninase (shown to be elevated in serum from diabetic patients), was not expressed in any PMA-treated MCLC, but present in GM-CSF-treated PBMCs. There was little overall difference in the pattern of expression of CD markers across all cells, though absolute expression levels varied considerably and the correlation between MCLCs and PBMCs was improved upon MCLC differentiation. Functionally, THP-1 and PBMCs migrated in response to chemoattractants in a transwell assay, with varying sensitivity to MCP-1, MIP-1α and LTB-4. However, despite similar gene and CD expression profiles, U-937 cells were functionally impaired as no migration was observed to any chemoattractant. Our analysis reveals that the MCLCs examined only partly replicate the genotypic and phenotypic properties of human PBMCs. To overcome such issues a universal differentiation protocol should be implemented for these cell lines, similar to those already used with isolated monocytes. Although not perfect, in our hands the THP-1 cells represent the closest, simplified surrogate model of PBMCs for study of inflammatory cell migration.

Induction of endothelial cell proliferation by angiogenic factors released by activated monocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pakala, Rajbabu; Watanabe, Takuya; Benedict, Claude R

2002-06-01

Introduction: Cell-cell interaction is an essential component of atherosclerotic plaque development. Activated monocytes appear to play a central role in the development of atherosclerosis, not only through foam cell formation but also via the production of various growth factors that induce proliferation of different cell types that are involved in the plaque development. Using serum free co-culture method, we determined the effect of monocytes on endothelial cell proliferation. Methods: Endothelial cell proliferation is determined by the amount of [{sup 3}H]thymidine incorporated in to the DNA. Basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) levels inmore » the conditioned medium were determined by ELISA. Results: Conditioned medium from unactivated monocytes partially inhibited endothelial cell proliferation, whereas conditioned medium from activated monocytes promoted endothelial cell proliferation. The mitogenic effect of conditioned medium derived from activated monocytes is due to the presence of b-FGF, VEGF and IL-8. Neutralizing antibodies against b-FGF, VEGF and IL-8 partially reversed the mitogenic effect of conditioned medium derived from activated monocytes. When b-FGF, VEGF and IL-8 were immunoprecipitated from conditioned medium derived from activated monocytes, it is less mitogenic to endothelial cells. Conclusion: Activated monocytes may play an important role in the development of atherosclerotic plaque by producing endothelial cell growth factors.« less

Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique

Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4{sup +} T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependentmore » phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The activated monocyte-like phenotype is mediated by TLR2/TLR4 signaling.« less

Silver nanoparticles impede phorbol myristate acetate-induced monocyte-macrophage differentiation and autophagy

NASA Astrophysics Data System (ADS)

Xu, Yingying; Wang, Liming; Bai, Ru; Zhang, Tianlu; Chen, Chunying

2015-09-01

Monocytes/macrophages are important constituents of the innate immune system. Monocyte-macrophage differentiation is not only crucial for innate immune responses, but is also related to some cardiovascular diseases. Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials because of their broad-spectrum antimicrobial properties. However, the effect of AgNPs on the functions of blood monocytes is scarcely reported. Here, we report the impedance effect of AgNPs on THP-1 monocyte differentiation, and that this effect was mediated by autophagy blockade and lysosomal impairment. Firstly, AgNPs inhibit phorbol 12-myristate 13-acetate (PMA)-induced monocyte differentiation by down-regulating both expression of surface marker CD11b and response to lipopolysaccharide (LPS) stimulation. Secondly, autophagy is activated during PMA-induced THP-1 monocyte differentiation, and the autophagy inhibitor chloroquine (CQ) can inhibit this process. Thirdly, AgNPs block the degradation of the autophagy substrate p62 and induce autophagosome accumulation, which demonstrates the blockade of autophagic flux. Fourthly, lysosomal impairments including alkalization and decrease of lysosomal membrane stability were observed in AgNP-treated THP-1 cells. In conclusion, we demonstrate that the impedance of monocyte-macrophage differentiation by AgNPs is mediated by autophagy blockade and lysosomal dysfunction. Our results suggest that crosstalk exists in different biological effects induced by AgNPs.

Cell Surface Trafficking of TLR1 Is Differentially Regulated by the Chaperones PRAT4A and PRAT4B*

PubMed Central

Hart, Bryan E.; Tapping, Richard I.

2012-01-01

The subcellular localization of Toll-like receptors (TLRs) is critical to their ability to function as innate immune sensors of microbial infection. We previously reported that an I602S polymorphism of human TLR1 is associated with aberrant trafficking of the receptor to the cell surface, loss of responses to TLR1 agonists, and differential susceptibility to diseases caused by pathogenic mycobacteria. Through an extensive analysis of receptor deletion and point mutants we have discovered that position 602 resides within a short 6 amino acid cytoplasmic region that is required for TLR1 surface expression. This short trafficking motif, in conjunction with the adjacent transmembrane domain, is sufficient to direct TLR1 to the cell surface. A serine at position 602 interrupts this trafficking motif and prevents cell surface expression of TLR1. Additionally, we have found that ER-resident TLR chaperones, PRAT4A and PRAT4B, act as positive and negative regulators of TLR1 surface trafficking, respectively. Importantly, either over-expression of PRAT4A or knock-down of PRAT4B rescues cell surface expression of the TLR1 602S variant. We also report that IFN-γ treatment of primary human monocytes derived from homozygous 602S individuals rescues TLR1 cell surface trafficking and cellular responses to soluble agonists. This event appears to be mediated by PRAT4A whose expression is strongly induced in human monocytes by IFN-γ. Collectively, these results provide a mechanism for the differential trafficking of TLR1 I602S variants, and highlight the distinct roles for PRAT4A and PRAT4B in the regulation of TLR1 surface expression. PMID:22447933

The sow endometrium at different stages of the oestrous cycle: immunohistochemical study on the distribution of SWC3-expressing cells (granulocytes, monocytes and macrophages).

PubMed

Kaeoket, K; Dalin, A M; Magnusson, U; Persson, E

2001-10-01

Uterine samples from sows taken immediately after slaughter at late di-oestrus, pro-oestrus, oestrus, early di-oestrus and di-ocstrus, were analysed by immunohistochemistry with an avidinbiotin-peroxidase method using a monoclonal antibody (anti-SWC3) to granulocyte, monocyte and macrophage populations. The endometrium was then examined by light microscopy. In the surface and glandular epithelium, the largest numbers of SWC3-expressing cells (P < or = 0.01 and P < or = 0.05) were found at oestrus, and at pro-oestrus and oestrus, respectively. The numbers of SWC3-expressing cells in the epithelium were positively correlated with the plasma levels of oestradiol-17beta. In the connective tissue of the subepithelial and glandular layers, no significant effect of the oestrous Cycle stage was found on the number of SWC3-expressing cells. The present study showed a variation in the distribution of SWC3-expressing cells in the sow endometrium, especially in the surface and glandular epithelium, during different stages of the oestrous cycle.

Bone morphogenetic protein 9 (BMP9) and BMP10 enhance tumor necrosis factor-α-induced monocyte recruitment to the vascular endothelium mainly via activin receptor-like kinase 2.

PubMed

Mitrofan, Claudia-Gabriela; Appleby, Sarah L; Nash, Gerard B; Mallat, Ziad; Chilvers, Edwin R; Upton, Paul D; Morrell, Nicholas W

2017-08-18

Bone morphogenetic proteins 9 and 10 (BMP9/BMP10) are circulating cytokines with important roles in endothelial homeostasis. The aim of this study was to investigate the roles of BMP9 and BMP10 in mediating monocyte-endothelial interactions using an in vitro flow adhesion assay. Herein, we report that whereas BMP9/BMP10 alone had no effect on monocyte recruitment, at higher concentrations both cytokines synergized with tumor necrosis factor-α (TNFα) to increase recruitment to the vascular endothelium. The BMP9/BMP10-mediated increase in monocyte recruitment in the presence of TNFα was associated with up-regulated expression levels of E-selectin, vascular cell adhesion molecule (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) on endothelial cells. Using siRNAs to type I and II BMP receptors and the signaling intermediaries (Smads), we demonstrated a key role for ALK2 in the BMP9/BMP10-induced surface expression of E-selectin, and both ALK1 and ALK2 in the up-regulation of VCAM-1 and ICAM-1. The type II receptors, BMPR-II and ACTR-IIA were both required for this response, as was Smad1/5. The up-regulation of cell surface adhesion molecules by BMP9/10 in the presence of TNFα was inhibited by LDN193189, which inhibits ALK2 but not ALK1. Furthermore, LDN193189 inhibited monocyte recruitment induced by TNFα and BMP9/10. BMP9/10 increased basal IκBα protein expression, but did not alter p65/RelA levels. Our findings suggest that higher concentrations of BMP9/BMP10 synergize with TNFα to induce the up-regulation of endothelial selectins and adhesion molecules, ultimately resulting in increased monocyte recruitment to the vascular endothelium. This process is mediated mainly via the ALK2 type I receptor, BMPR-II/ACTR-IIA type II receptors, and downstream Smad1/5 signaling. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Mycobacterium leprae alters classical activation of human monocytes in vitro.

PubMed

Fallows, Dorothy; Peixoto, Blas; Kaplan, Gilla; Manca, Claudia

2016-01-01

Macrophages play a central role in the pathogenesis of leprosy, caused by Mycobacterium leprae. The polarized clinical presentations in leprosy are associated with differential immune activation. In tuberculoid leprosy, macrophages show a classical activation phenotype (M1), while macrophages in lepromatous disease display characteristics of alternative activation (M2). Bacille Calmette-Guérin (BCG) vaccination, which protects against leprosy, can promote sustained changes in monocyte response to unrelated pathogens and may preferentially direct monocytes towards an M1 protective phenotype. We previously reported that M. leprae can dampen the response of naïve human monocytes to a strong inducer of pro-inflammatory cytokines, such as BCG. Here, we investigated the ability of the pathogen to alter the direction of macrophage polarization and the impact of BCG vaccination on the monocyte response to M. leprae. We show that in vitro exposure of monocytes from healthy donors to M. leprae interferes with subsequent M1 polarization, indicated by lower levels of M1-associated cytokine/chemokines released and reduced expression of M1 cell surface markers. Exposure to M. leprae phenolic glycolipid (PGL) 1, instead of whole bacteria, demonstrated a similar effect on M1 cytokine/chemokine release. In addition, we found that monocytes from 10-week old BCG-vaccinated infants released higher levels of the pro-inflammatory cytokines TNF-α and IL-1β in response to M. leprae compared to those from unvaccinated infants. Exposure to M. leprae has an inhibitory effect on M1 macrophage polarization, likely mediated through PGL-1. By directing monocyte/macrophages preferentially towards M1 activation, BCG vaccination may render the cells more refractory to the inhibitory effects of subsequent M. leprae infection.

Latency-Associated Expression of Human Cytomegalovirus US28 Attenuates Cell Signaling Pathways To Maintain Latent Infection

PubMed Central

Krishna, Benjamin A.; Poole, Emma L.; Smit, Martine J.; Wills, Mark R.

2017-01-01

ABSTRACT Reactivation of human cytomegalovirus (HCMV) latent infection from early myeloid lineage cells constitutes a threat to immunocompromised or immune-suppressed individuals. Consequently, understanding the control of latency and reactivation to allow targeting and killing of latently infected cells could have far-reaching clinical benefits. US28 is one of the few viral genes that is expressed during latency and encodes a cell surface G protein-coupled receptor (GPCR), which, during lytic infection, is a constitutive cell-signaling activator. Here we now show that in monocytes, which are recognized sites of HCMV latency in vivo, US28 attenuates multiple cell signaling pathways, including mitogen-activated protein (MAP) kinase and NF-κB, and that this is required to establish a latent infection; viruses deleted for US28 initiate a lytic infection in infected monocytes. We also show that these monocytes then become potent targets for the HCMV-specific host immune response and that latently infected cells treated with an inverse agonist of US28 also reactivate lytic infection and similarly become immune targets. Consequently, we suggest that the use of inhibitors of US28 could be a novel immunotherapeutic strategy to reactivate the latent viral reservoir, allowing it to be targeted by preexisting HCMV-specific T cells. PMID:29208743

Monocytic leukemias.

PubMed

Shaw, M T

1980-05-01

The monocytic leukemias may be subdivided into acute monocytic leukemia, acute myelomonocytic leukemia, and subacute and chronic myelomonocytic leukemia. The clinical features of acute monocytic and acute myelomonocytic leukemias are similar and are manifestations of bone marrow failure. Gingival hypertrophy and skin infiltration are more frequent in acute monocytic leukemia. Cytomorphologically the blast cells in acute monocytic leukemia may be undifferentiated or differentiated, whereas in the acute myelomonocytic variety there are mixed populations of monocytic and myeloblastic cells. Cytochemical characteristics include strongly positive reactions for nonspecific esterase, inhibited by fluoride. The functional characteristics of acute monocytic and acute myelomonocytic cells resemble those of monocytes and include glass adherence and phagocytoses, the presence of Fc receptors for IgG and C'3, and the production of colony stimulating activity. Subacute and chronic myelomonocytic leukemias are insidious and slowly progressive diseases characterized by anemia and peripheral blood monocytosis. Atypical monocytes called paramyeloid cells are characteristic. The drugs used in the treatment of acute monocytic and acute myelomonocytic leukemias include cytosine arabinoside, the anthracyclines, and VP 16-213. Drug therapy in subacute and chronic myelomonocytic leukemias is not usually indicated, although VP 16-213 has been claimed to be effective.

C/EBP epsilon directs granulocytic versus monocytic lineage determination and confers chemotactic function via Hlx

PubMed Central

Halene, Stephanie; Gaines, Peter; Sun, Hong; Zibello, Theresa; Lin, Sharon; Khanna-Gupta, Arati; Williams, Simon C.; Perkins, Archibald; Krause, Diane; Berliner, Nancy

2010-01-01

Objective Mutations in the C/EBPε gene have been identified in the cells of patients with neutrophil specific granule deficiency (SGD), a rare congenital disorder marked by recurrent bacterial infections. Their neutrophils, in addition to lacking specific granules required for normal respiratory burst activity, also lack normal phagocytosis and chemotaxis. Although the SGD phenotype has been replicated in C/EBPε−/− (KO) mice, the mechanisms by which C/EBPε mutations act to decrease neutrophil function are not entirely clear. Methods In order to determine the role of C/EBPε in neutrophil differentiation and migration, we generated immortalized progenitor cell lines from C/EBPε KO and wild type (WT) mice and performed expression and flow cytometric analysis and functional studies. Results Expression of lineage specific cell surface antigens on our in vitro differentiated cell lines revealed persistent expression of monocytic markers on KO granulocytes. We verified this in primary murine peripheral blood and bone marrow cells. In addition, KO BM had an increase in immature myeloid precursors at the common myeloid progenitor (CMP) and granulocyte monocyte progenitor (GMP) level suggesting a critical role for C/EBPε not only in granulocyte maturation beyond the promyelocyte stage, but also in the monocyte/granulocyte lineage decision. We found that restoration of Hlx (H2.0-like homeo box 1) expression, which was decreased in C/EBPε KO cells, rescued chemotaxis, but not the other defects of C/EBPε KO neutrophils. Summary We show two new regulatory functions of C/EBPε in myelopoiesis: in the absence of C/EBPε, there is not only incomplete differentiation of granulocytes, but myelopoiesis is disrupted with the appearance of an intermediate cell type with monocyte and granulocyte features, and the neutrophils have abnormal chemotaxis. Restoration of expression of Hlx provides partial recovery of function; it has no effect on neutrophil maturation, but can completely ameliorate the chemotaxis defect in C/EBPe KO cells. PMID:19925846

Differential procoagulant activity of microparticles derived from monocytes, granulocytes, platelets and endothelial cells: impact of active tissue factor.

PubMed

Shustova, Olga N; Antonova, Olga A; Golubeva, Nina V; Khaspekova, Svetlana G; Yakushkin, Vladimir V; Aksuk, Svetlana A; Alchinova, Irina B; Karganov, Mikhail Y; Mazurov, Alexey V

2017-07-01

: Microparticles released by activated/apoptotic cells exhibit coagulation activity as they express phosphatidylserine and some of them - tissue factor. We compared procoagulant properties of microparticles from monocytes, granulocytes, platelets and endothelial cells and assessed the impact of tissue factor in observed differences. Microparticles were sedimented (20 000g, 30 min) from the supernatants of activated monocytes, monocytic THP-1 cells, granulocytes, platelets and endothelial cells. Coagulation activity of microparticles was examined using plasma recalcification assay. The size of microparticles was evaluated by dynamic light scattering. Tissue factor activity was measured by its ability to activate factor X. All microparticles significantly accelerated plasma coagulation with the shortest lag times for microparticles derived from monocytes, intermediate - for microparticles from THP-1 cells and endothelial cells, and the longest - for microparticles from granulocytes and platelets. Average diameters of microparticles ranged within 400-600 nm. The largest microparticles were produced by endothelial cells and granulocytes, smaller - by monocytes, and the smallest - by THP-1 cells and platelets. The highest tissue factor activity was detected in microparticles from monocytes, lower activity - in microparticles from endothelial cells and THP-1 cells, and no activity - in microparticles from platelets and granulocytes. Anti-tissue factor antibodies extended coagulation lag times for microparticles from monocytes, endothelial cells and THP-1 cells and equalized them with those for microparticles from platelets and granulocytes. Higher coagulation activity of microparticles from monocytes, THP-1 cells and endothelial cells in comparison with microparticles from platelets and granulocytes is determined mainly by the presence of active tissue factor.

Immunoregulatory Profile of Monocytes from Cutaneous Leishmaniasis Patients and Association with Lesion Size

PubMed Central

Vieira, Érica L. M.; Keesen, Tatjana S. L.; Machado, Paulo R.; Guimarães, Luiz H.; Carvalho, Edgar M.; Dutra, Walderez O.; Gollob, Kenneth J.

2013-01-01

Leishmaniasis is an important tropical disease composed of several clinical forms that adversely affect millions of people globally. Critical cells involved in the host-Leishmania interaction are monocytes and macrophages, which act to protect against infections due to their ability to both control intracellular infections and regulate the subsequent adaptive immune response. Both soluble factors and cell surface receptors are key in directing the immune response following interaction with pathogens such as Leishmania. Toll like receptors (TLRs) have an essential role in immune responses against infections, but little is known about their role in human infection with Leishmania braziliensis. In this work, we evaluated peripheral blood CD14+ monocytes for expression of immunoregulatory cytokines, co-stimulatory molecules and TLR9 from cutaneous leishmaniasis patients infected with L. braziliensis and non-infected individuals. Our results showed that patients present decreased expression of co-stimulatory molecules, such as CD80 and CD86 following culture with media alone or after stimulus with soluble Leishmania antigen. Interestingly, TLR9 expression was higher after culture with SLA suggesting a role for this molecule in immunoregulation of active disease. Lastly, higher frequencies of TLR9+ monocytes were correlated with greater lesion size. These findings demonstrate a peripheral monocytes profile compatible with important immunoregulatory potential. PMID:23050581

Abnormalities in iNKT cells are associated with impaired ability of monocytes to produce IL-10 and suppress T-cell proliferation in sarcoidosis.

PubMed

Crawshaw, Anjali; Kendrick, Yvonne R; McMichael, Andrew J; Ho, Ling-Pei

2014-07-01

Sarcoidosis is a multisystem granulomatous disorder characterized by marked T-cell expansion of T helper 1 (Th1) cells. The cause of T-cell overactivity is unknown. We hypothesized that interleukin-10 (IL-10) production by a yet undefined cell type might be defective, resulting in loss of regulation of T-cell activity. Focusing on IL-10-producing monocytes, we first showed that monocytes isolated from the peripheral blood of corticosteroid-naïve sarcoidosis patients (n = 51) produced less IL-10 compared to controls, and were less able to suppress T-cell proliferation. In addition, monocytic IL-10 production correlated negatively with disease activity score. As invariant natural killer T (iNKT) cells are known to both interact with monocytes and be reduced in sarcoidosis patients, we then asked whether iNKT-specific defects might be responsible for this reduced IL-10 production. We found that greater numbers of circulating iNKT cells was associated with higher IL-10 production. Moreover, iNKT cells enhanced monocytic IL-10 production in vitro. Defective IL-10 production and T-cell suppression by sarcoidosis monocytes could be restored following their coculture with iNKT cells, in a CD1d- and cell contact-dependent process. We suggest that reduced iNKT-cell numbers in sarcoidosis may lead to impaired monocytic IL-10 production and unchecked T-cell expansion in sarcoidosis. These findings provide fresh insight into the mechanism of sarcoidosis disease, and interaction between iNKT cells and monocytes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Changes of monocyte and monocyte-platelet aggregates in different subgroups of thrombotic events in patients with acute myocardial infarction during PCI].

PubMed

Wang, Sheng; Sun, Cuifang; Liao, Wang; Wu, Zhongwei; Wang, Yudai; Huang, Xiuxian; Lu, Sijia; Dong, Xiaoli; Shuai, Fujie; Li, Bin

2017-07-01

Objective To investigate the impact of thrombotic events on the alterations of monocyte and monocyte-platelet aggregates (MPAs) in patients with acute myocardial infarction (AMI) during percutaneous coronary intervention (PCI). Methods Blood was collected before PCI for flow cytometry. Monocyte subsets and MPAs were detected by four-color platform (CDl4-APC, CDl6-PE-Cy7, CD86-PE and CD41-Alexa Fluor R 488). According to the expression of the platelet surface marker CD41, the number of monocyte subsets and MPAs was analyzed using the fluorescent microspheres of absolute counting tube. The Wilcoxon rank sum test and receiver operating characteristic (ROC) curve analysis were performed. Results CD14 + CD16 ++ monocytes in intraprocedural thrombotic events (IPTE) group were significantly fewer than those in non-IPTE group, and the percentage in total mononuclear cells decreased. Compared with non-IPTE group, MPA binding ratio and monocyte subset MPA binding ratio were significantly higher in IPTE group. ROC analysis showed that MPA binding ratio and subgroup MPA binding ratio had a better predictive value for IPTE in patients with AMI. Conclusion The CD14 + CD16 ++ monocytes in IPTE group were significantly fewer than those in the non-IPTE group. MPA binding ratio and MPA binding ratio of monocyte subsets were significantly higher in the IPTE group than in the non-IPTE group, so they have a good predictive value for IPTE in patients with AMI.

ERAP1 reduces accumulation of aberrant and disulfide-linked forms of HLA-B27 on the cell surface.

PubMed

Tran, Tri M; Hong, Sohee; Edwan, Jehad H; Colbert, Robert A

2016-06-01

Endoplasmic reticulum (ER) aminopeptidase 1 (ERAP1) variants contribute to the risk of ankylosing spondylitis in HLA-B27 positive individuals, implying a disease-related interaction between these gene products. The aim of this study was to determine whether reduced ERAP1 expression would alter the cell surface expression of HLA-B27 and the formation of aberrant disulfide-linked forms that have been implicated in the pathogenesis of spondyloarthritis. ERAP1 expression was knocked down in monocytic U937 cells expressing HLA-B27 and endogenous HLA class I. The effect of ERAP1 knockdown on the accumulation HLA-B alleles (B18, B51, and B27) was assessed using immunoprecipitation, isoelectric focusing, and immunoblotting, as well as flow cytometry with antibodies specific for different forms of HLA-B27. Cell surface expression of aberrant disulfide-linked HLA-B27 dimers was assessed by immunoprecipitation and electrophoresis on non-reducing polyacrylamide gels. ERAP1 knockdown increased the accumulation of HLA-B27 on the cell surface including disulfide-linked dimers, but had no effect on levels of HLA-B18 or -B51. Antibodies with unique specificity for HLA-B27 confirmed increased cell surface expression of complexes shown previously to contain long peptides. IFN-γ treatment resulted in striking increases in the expression of disulfide-linked HLA-B27 heavy chains, even in cells with normal ERAP1 expression. Our results suggest that normal levels of ERAP1 reduce the accumulation of aberrant and disulfide-linked forms of HLA-B27 in monocytes, and thus help to maintain the integrity of cell surface HLA-B27 complexes. Published by Elsevier Ltd.

ERAP1 Reduces Accumulation of Aberrant and Disulfide-Linked Forms of HLA-B27 on the Cell Surface

PubMed Central

Tran, Tri; Hong, Sohee; Edwan, Jehad; Colbert, Robert A.

2016-01-01

Objective Endoplasmic reticulum (ER) aminopeptidase 1 (ERAP1) variants contribute to the risk of ankylosing spondylitis in HLA-B27 positive individuals, implying a disease-related interaction between these gene products. The aim of this study was to determine whether reduced ERAP1 expression would alter the cell surface expression of HLA-B27 and the formation of aberrant disulfide-linked forms that have been implicated in the pathogenesis of spondyloarthritis. Methods ERAP1 expression was knocked down in monocytic U937 cells expressing HLA-B27 and endogenous HLA class I. The effect of ERAP1 knockdown on the accumulation HLA-B alleles (B18, B51, and B27) was assessed using immunoprecipitation, isoelectric focusing, and immunoblotting, as well as flow cytometry with antibodies specific for different forms of HLA-B27. Cell surface expression of aberrant disulfide-linked HLA-B27 dimers was assessed by immunoprecipitation and electrophoresis on non-reducing polyacrylamide gels. Results ERAP1 knockdown increased the accumulation of HLA-B27 on the cell surface including disulfide-linked dimers, but had no effect on levels of HLA-B18 or -B51. Antibodies with unique specificity for HLA-B27 confirmed increased cell surface expression of complexes shown previously to contain long peptides. IFN-γ treatment resulted in striking increases in the expression of disulfide-linked HLA-B27 heavy chains, even in cells with normal ERAP1 expression. Conclusions Our results suggest that normal levels of ERAP1 reduce the accumulation of aberrant and disulfide-linked forms of HLA-B27 in monocytes, and thus help to maintain the integrity of cell surface HLA-B27 complexes. PMID:27107845

Protective role of klotho protein on epithelial cells upon co-culture with activated or senescent monocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mytych, Jennifer, E-mail: jennifermytych@gmail.com; Centre of Applied Biotechnology and Basic Sciences, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa; Wos, Izabela

Monocytes ensure proper functioning and maintenance of epithelial cells, while good condition of monocytes is a key factor of these interactions. Although, it was shown that in some circumstances, a population of altered monocytes may appear, there is no data regarding their effect on epithelial cells. In this study, using direct co-culture model with LPS-activated and Dox-induced senescent THP-1 monocytes, we reported for the first time ROS-induced DNA damage, reduced metabolic activity, proliferation inhibition and cell cycle arrest followed by p16-, p21- and p27-mediated DNA damage response pathways activation, premature senescence and apoptosis induction in HeLa cells. Also, we showmore » that klotho protein possessing anti-aging and anti-inflammatory characteristics reduced cytotoxic and genotoxic events by inhibition of insulin/IGF-IR and downregulation of TRF1 and TRF2 proteins. Therefore, klotho protein could be considered as a protective factor against changes caused by altered monocytes in epithelial cells. - Highlights: • Activated and senescent THP-1 monocytes induced cyto- and genotoxicity in HeLa cells. • Altered monocytes provoked oxidative and nitrosative stress-induced DNA damage. • DNA damage activated DDR pathways and lead to premature senescence and apoptosis. • Klotho reduced ROS/RNS-mediated toxicity through insulin/IGF-IR pathway inhibition. • Klotho protects HeLa cells from cyto- and genotoxicity induced by altered monocytes.« less

Interaction studies reveal specific recognition of an anti-inflammatory polyphosphorhydrazone dendrimer by human monocytes

NASA Astrophysics Data System (ADS)

Ledall, Jérémy; Fruchon, Séverine; Garzoni, Matteo; Pavan, Giovanni M.; Caminade, Anne-Marie; Turrin, Cédric-Olivier; Blanzat, Muriel; Poupot, Rémy

2015-10-01

Dendrimers are nano-materials with perfectly defined structure and size, and multivalency properties that confer substantial advantages for biomedical applications. Previous work has shown that phosphorus-based polyphosphorhydrazone (PPH) dendrimers capped with azabisphosphonate (ABP) end groups have immuno-modulatory and anti-inflammatory properties leading to efficient therapeutic control of inflammatory diseases in animal models. These properties are mainly prompted through activation of monocytes. Here, we disclose new insights into the molecular mechanisms underlying the anti-inflammatory activation of human monocytes by ABP-capped PPH dendrimers. Following an interdisciplinary approach, we have characterized the physicochemical and biological behavior of the lead ABP dendrimer with model and cell membranes, and compared this experimental set of data to predictive computational modelling studies. The behavior of the ABP dendrimer was compared to the one of an isosteric analog dendrimer capped with twelve azabiscarboxylate (ABC) end groups instead of twelve ABP end groups. The ABC dendrimer displayed no biological activity on human monocytes, therefore it was considered as a negative control. In detail, we show that the ABP dendrimer can bind both non-specifically and specifically to the membrane of human monocytes. The specific binding leads to the internalization of the ABP dendrimer by human monocytes. On the contrary, the ABC dendrimer only interacts non-specifically with human monocytes and is not internalized. These data indicate that the bioactive ABP dendrimer is recognized by specific receptor(s) at the surface of human monocytes.Dendrimers are nano-materials with perfectly defined structure and size, and multivalency properties that confer substantial advantages for biomedical applications. Previous work has shown that phosphorus-based polyphosphorhydrazone (PPH) dendrimers capped with azabisphosphonate (ABP) end groups have immuno-modulatory and anti-inflammatory properties leading to efficient therapeutic control of inflammatory diseases in animal models. These properties are mainly prompted through activation of monocytes. Here, we disclose new insights into the molecular mechanisms underlying the anti-inflammatory activation of human monocytes by ABP-capped PPH dendrimers. Following an interdisciplinary approach, we have characterized the physicochemical and biological behavior of the lead ABP dendrimer with model and cell membranes, and compared this experimental set of data to predictive computational modelling studies. The behavior of the ABP dendrimer was compared to the one of an isosteric analog dendrimer capped with twelve azabiscarboxylate (ABC) end groups instead of twelve ABP end groups. The ABC dendrimer displayed no biological activity on human monocytes, therefore it was considered as a negative control. In detail, we show that the ABP dendrimer can bind both non-specifically and specifically to the membrane of human monocytes. The specific binding leads to the internalization of the ABP dendrimer by human monocytes. On the contrary, the ABC dendrimer only interacts non-specifically with human monocytes and is not internalized. These data indicate that the bioactive ABP dendrimer is recognized by specific receptor(s) at the surface of human monocytes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03884g

TLR8-driven IL-12-dependent reciprocal and synergistic activation of NK cells and monocytes by immunostimulatory RNA.

PubMed

Berger, Michael; Ablasser, Andrea; Kim, Sarah; Bekeredjian-Ding, Isabelle; Giese, Thomas; Endres, Stefan; Hornung, Veit; Hartmann, Gunther

2009-04-01

Immunostimulatory RNA (isRNA) depending on sequence and structure can function as a ligand for Toll-like receptor (TLR) 7 and TLR8. Here we show that isRNA induces high levels of bioactive interleukin-12 in purified human monocytes, whereas purified natural killer (NK) cells did not respond. However, in a coculture of monocytes and NK cells, isRNA dramatically increased NK cell function. Activation of monocytes and NK cells was bidirectional, as monocytes in the presence of NK cells produced higher levels of bioactive interleukin-12. As a result of the monocyte-NK cell interaction in peripheral blood mononuclear cells isRNA induced high levels of interferon (IFN)-gamma in NK cells and strong NK cell-mediated cytotoxic activity. Induction of simultaneous IFN-gamma production and lytic activity by isRNA in NK cells was higher as compared with other established nucleic acid or small molecule TLR ligands. Our studies demonstrate that monocytes play a pivotal role in the orchestration of a strong NK cell response. With early NK cell-dependent IFN-gamma production being critical for the development of antigen-specific cytotoxic T lymphocyte responses, newly developed isRNA-based TLR8 ligands join the list of promising oligonucleotides for immunotherapy of viral infection and cancer.

Osteoblast and monocyte responses to 444 ferritic stainless steel intended for a magneto-mechanically actuated fibrous scaffold.

PubMed

Malheiro, Vera N; Spear, Rose L; Brooks, Roger A; Markaki, Athina E

2011-10-01

The rationale behind this work is to design an implant device, based on a ferromagnetic material, with the potential to deform in vivo promoting osseointegration through the growth of a healthy periprosthetic bone structure. One of the primary requirements for such a device is that the material should be non-inflammatory and non-cytotoxic. In the study described here, we assessed the short-term cellular response to 444 ferritic stainless steel; a steel, with a very low interstitial content and a small amount of strong carbide-forming elements to enhance intergranular corrosion resistance. Two different human cell types were used: (i) foetal osteoblasts and (ii) monocytes. Austenitic stainless steel 316L, currently utilised in many commercially available implant designs, and tissue culture plastic were used as the control surfaces. Cell viability, proliferation and alkaline phosphatase activity were measured. In addition, cells were stained with alizarin red and fluorescently-labelled phalloidin and examined using light, fluorescence and scanning electron microscopy. Results showed that the osteoblast cells exhibited a very similar degree of attachment, growth and osteogenic differentiation on all surfaces. Measurement of lactate dehydrogenase activity and tumour necrosis factor alpha protein released from human monocytes indicated that 444 stainless steel did not cause cytotoxic effects or any significant inflammatory response. Collectively, the results suggest that 444 ferritic stainless steel has the potential to be used in advanced bone implant designs. Copyright © 2011 Elsevier Ltd. All rights reserved.

CXCL4 and CXCL4L1 Differentially Affect Monocyte Survival and Dendritic Cell Differentiation and Phagocytosis

PubMed Central

Gouwy, Mieke; Ruytinx, Pieter; Radice, Egle; Claudi, Federico; Van Raemdonck, Katrien; Bonecchi, Raffaella; Locati, Massimo; Struyf, Sofie

2016-01-01

Upon inflammation, circulating monocytes leave the bloodstream and migrate into the tissues, where they differentiate after exposure to various growth factors, cytokines or infectious agents. The best defined macrophage polarization types are M1 and M2. However, the platelet-derived CXC chemokine CXCL4 induces the polarization of macrophages into a unique phenotype. In this study, we compared the effect of CXCL4 and its variant CXCL4L1 on the differentiation of monocytes into macrophages and into immature monocyte-derived dendritic cells (iMDDC). Differently to M-CSF and CXCL4, CXCL4L1 is not a survival factor for monocytes. Moreover, the expression of the chemokine receptors CCR2, CCR5 and CXCR3 was significantly higher on CXCL4L1-treated monocytes compared to M-CSF- and CXCL4-stimulated monocytes. IL-1 receptor antagonist (IL-1RN) expression was upregulated by CXCL4 and downregulated by CXCL4L1, respectively, whereas both chemokines reduced the expression of the mannose receptor (MRC). Furthermore, through activation of CXCR3, CXCL4L1-stimulated monocytes released significantly higher amounts of CCL2 and CXCL8 compared to CXCL4-treated monocytes, indicating more pronounced inflammatory traits for CXCL4L1. In contrast, in CXCL4L1-treated monocytes, the production of CCL22 was lower. Compared to iMDDC generated in the presence of CXCL4L1, CXCL4-treated iMDDC showed an enhanced phagocytic capacity and downregulation of expression of certain surface markers (e.g. CD1a) and specific enzymes (e.g. MMP-9 and MMP-12). CXCL4 and CXCL4L1 did not affect the chemokine receptor expression on iMDDC and cytokine production (CCL2, CCL18, CCL22, CXCL8, IL-10) by CXCL4- or CXCL4L1-differentiated iMDDC was similar. We can conclude that both CXCL4 and CXCL4L1 exert a direct effect on monocytes and iMDDC. However, the resulting phenotypes are different, which suggests a unique role for the two CXCL4 variants in physiology and/or pathology. PMID:27828999

CXCL4 and CXCL4L1 Differentially Affect Monocyte Survival and Dendritic Cell Differentiation and Phagocytosis.

PubMed

Gouwy, Mieke; Ruytinx, Pieter; Radice, Egle; Claudi, Federico; Van Raemdonck, Katrien; Bonecchi, Raffaella; Locati, Massimo; Struyf, Sofie

2016-01-01

Upon inflammation, circulating monocytes leave the bloodstream and migrate into the tissues, where they differentiate after exposure to various growth factors, cytokines or infectious agents. The best defined macrophage polarization types are M1 and M2. However, the platelet-derived CXC chemokine CXCL4 induces the polarization of macrophages into a unique phenotype. In this study, we compared the effect of CXCL4 and its variant CXCL4L1 on the differentiation of monocytes into macrophages and into immature monocyte-derived dendritic cells (iMDDC). Differently to M-CSF and CXCL4, CXCL4L1 is not a survival factor for monocytes. Moreover, the expression of the chemokine receptors CCR2, CCR5 and CXCR3 was significantly higher on CXCL4L1-treated monocytes compared to M-CSF- and CXCL4-stimulated monocytes. IL-1 receptor antagonist (IL-1RN) expression was upregulated by CXCL4 and downregulated by CXCL4L1, respectively, whereas both chemokines reduced the expression of the mannose receptor (MRC). Furthermore, through activation of CXCR3, CXCL4L1-stimulated monocytes released significantly higher amounts of CCL2 and CXCL8 compared to CXCL4-treated monocytes, indicating more pronounced inflammatory traits for CXCL4L1. In contrast, in CXCL4L1-treated monocytes, the production of CCL22 was lower. Compared to iMDDC generated in the presence of CXCL4L1, CXCL4-treated iMDDC showed an enhanced phagocytic capacity and downregulation of expression of certain surface markers (e.g. CD1a) and specific enzymes (e.g. MMP-9 and MMP-12). CXCL4 and CXCL4L1 did not affect the chemokine receptor expression on iMDDC and cytokine production (CCL2, CCL18, CCL22, CXCL8, IL-10) by CXCL4- or CXCL4L1-differentiated iMDDC was similar. We can conclude that both CXCL4 and CXCL4L1 exert a direct effect on monocytes and iMDDC. However, the resulting phenotypes are different, which suggests a unique role for the two CXCL4 variants in physiology and/or pathology.

A new and efficient culture method for porcine bone marrow-derived M1- and M2-polarized macrophages.

PubMed

Gao, Jiye; Scheenstra, Maaike R; van Dijk, Albert; Veldhuizen, Edwin J A; Haagsman, Henk P

2018-06-01

Macrophages play an important role in the innate immune system as part of the mononuclear phagocyte system (MPS). They have a pro-inflammatory signature (M1-polarized macrophages) or anti-inflammatory signature (M2-polarized macrophages) based on expression of surface receptors and secretion of cytokines. However, very little is known about the culture of macrophages from pigs and more specific about the M1 and M2 polarization in vitro. Porcine monocytes or mononuclear bone marrow cells were used to culture M1- and M2-polarized macrophages in the presence of GM-CSF and M-CSF, respectively. Surface receptor expression was measured with flow cytometry and ELISA was used to quantify cytokine secretion in response to LPS and PAM 3 CSK 4 stimulation. Human monocyte-derived macrophages were used as control. Porcine M1- and M2-polarized macrophages were cultured best using porcine GM-CSF and murine M-CSF, respectively. Cultures from bone marrow cells resulted in a higher yield M1- and M2-polarized macrophages which were better comparable to human monocyte-derived macrophages than cultures from porcine monocytes. Porcine M1-polarized macrophages displayed the characteristic fried egg shape morphology, lower CD163 expression and low IL-10 production. Porcine M2-polarized macrophages contained the spindle-like morphology, higher CD163 expression and high IL-10 production. Porcine M1- and M2-polarized macrophages can be most efficiently cultured from mononuclear bone marrow cells using porcine GM-CSF and murine M-CSF. The new culture method facilitates more refined studies of porcine macrophages in vitro, important for both porcine and human health since pigs are increasingly used as model for translational research. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

INVOLVEMENT OF TOLL-LIKE RECEPTOR 4 AND MAPK PATHWAYS IN LPS-INDUCED CD40 EXPRESSION IN MONOCYTIC CELLS

EPA Science Inventory

CD40 is a co-stimulatory surface molecule actively expressed on mature dendritic cells (DC). Recent studies suggest that endotoxin (LPS) inhalation induces DC maturation in the airways of healthy volunteers. To characterize the effect of LPS on CD40 expression and underlying mech...

Zoledronic acid causes γδ T cells to target monocytes and down-modulate inflammatory homing

PubMed Central

Fowler, Daniel W; Copier, John; Dalgleish, Angus G; Bodman-Smith, Mark D

2014-01-01

Zoledronic acid (ZA) is a potential immunotherapy for cancer because it can induce potent γδ T-cell-mediated anti-tumour responses. Clinical trials are testing the efficacy of intravenous ZA in cancer patients; however, the effects of systemic ZA on the activation and migration of peripheral γδ T cells remain poorly understood. We found that γδ T cells within ZA-treated peripheral blood mononuclear cells were degranulating, as shown by up-regulated expression of CD107a/b. Degranulation was monocyte dependent because CD107a/b expression was markedly reduced in the absence of CD14+ cells. Consistent with monocyte-induced degranulation, we observed γδ T-cell-dependent induction of monocyte apoptosis, as shown by phosphatidylserine expression on monocytes and decreased percentages of monocytes in culture. Despite the prevailing paradigm that ZA promotes tumour homing in γδ T cells, we observed down-modulation of their tumour homing capacity, as shown by decreased expression of the inflammatory chemokine receptors CCR5 and CXCR3, and reduced migration towards the inflammatory chemokine CCL5. Taken together our data suggest that ZA causes γδ T cells to target monocytes and down-modulate the migratory programme required for inflammatory homing. This study provides novel insight into how γδ T cells interact with monocytes and the possible implications of systemic use of ZA in cancer. PMID:24912747

Thermo-responsive cell culture carrier: Effects on macrophage functionality and detachment efficiency.

PubMed

Rennert, Knut; Nitschke, Mirko; Wallert, Maria; Keune, Natalie; Raasch, Martin; Lorkowski, Stefan; Mosig, Alexander S

2017-01-01

Harvesting cultivated macrophages for tissue engineering purposes by enzymatic digestion of cell adhesion molecules can potentially result in unintended activation, altered function, or behavior of these cells. Thermo-responsive polymer is a promising tool that allows for gentle macrophage detachment without artificial activation prior to subculture within engineered tissue constructs. We therefore characterized different species of thermo-responsive polymers for their suitability as cell substrate and to mediate gentle macrophage detachment by temperature shift. Primary human monocyte- and THP-1-derived macrophages were cultured on thermo-responsive polymers and characterized for phagocytosis and cytokine secretion in response to lipopolysaccharide stimulation. We found that both cell types differentially respond in dependence of culture and stimulation on thermo-responsive polymers. In contrast to THP-1 macrophages, primary monocyte-derived macrophages showed no signs of impaired viability, artificial activation, or altered functionality due to culture on thermo-responsive polymers compared to conventional cell culture. Our study demonstrates that along with commercially available UpCell carriers, two other thermo-responsive polymers based on poly(vinyl methyl ether) blends are attractive candidates for differentiation and gentle detachment of primary monocyte-derived macrophages. In summary, we observed similar functionality and viability of primary monocyte-derived macrophages cultured on thermo-responsive polymers compared to standard cell culture surfaces. While this first generation of custom-made thermo-responsive polymers does not yet outperform standard culture approaches, our results are very promising and provide the basis for exploiting the unique advantages offered by custom-made thermo-responsive polymers to further improve macrophage culture and recovery in the future, including the covalent binding of signaling molecules and the reduction of centrifugation and washing steps. Optimizing these and other benefits of thermo-responsive polymers could greatly improve the culture of macrophages for tissue engineering applications.

Phenotypic and Functional Changes in Blood Monocytes Following Adherence to Endothelium

PubMed Central

Tso, Colin; Rye, Kerry-Anne; Barter, Philip

2012-01-01

Objective Blood monocytes are known to express endothelial-like genes during co-culture with endothelium. In this study, the time-dependent change in the phenotype pattern of primary blood monocytes after adhering to endothelium is reported using a novel HLA-A2 mistyped co-culture model. Methods and Results Freshly isolated human PBMCs were co-cultured with human umbilical vein endothelial cells or human coronary arterial endothelial cells of converse human leukocyte antigen A2 (HLA-A2) status. This allows the tracking of the PBMC-derived cells by HLA-A2 expression and assessment of their phenotype pattern over time. PBMCs that adhered to the endothelium at the start of the co-culture were predominantly CD11b+ blood monocytes. After 24 to 72 hours in co-culture, the endothelium-adherent monocytes acquired endothelial-like properties including the expression of endothelial nitric oxide synthase, CD105, CD144 and vascular endothelial growth factor receptor 2. The expression of monocyte/macrophage lineage antigens CD14, CD11b and CD36 were down regulated concomitantly. The adherent monocytes did not express CD115 after 1 day of co-culture. By day 6, the monocyte-derived cells expressed vascular cell adhesion molecule 1 in response to tumour necrosis factor alpha. Up to 10% of the PBMCs adhered to the endothelium. These monocyte-derived cells contributed up to 30% of the co-cultured cell layer and this was dose-dependent on the PBMC seeding density. Conclusions Human blood monocytes undergo rapid phenotype change to resemble endothelial cells after adhering to endothelium. PMID:22615904

Monocytes from HIV+ individuals show impaired cholesterol efflux and increased foam cell formation after transendothelial migration

PubMed Central

MAISA, Anna; HEARPS, Anna C.; ANGELOVICH, Thomas A.; PEREIRA, Candida F.; ZHOU, Jingling; SHI, Margaret D.Y.; PALMER, Clovis S.; MULLER, William A.; CROWE, Suzanne M.; JAWOROWSKI, Anthony

2016-01-01

Design HIV+ individuals have an increased risk of atherosclerosis and cardiovascular disease which is independent of antiretroviral therapy and traditional risk factors. Monocytes play a central role in the development of atherosclerosis, and HIV-related chronic inflammation and monocyte activation may contribute to increased atherosclerosis, but the mechanisms are unknown. Methods Using an in vitro model of atherosclerotic plaque formation, we measured the transendothelial migration of purified monocytes from age-matched HIV+ and uninfected donors and examined their differentiation into foam cells. Cholesterol efflux and the expression of cholesterol metabolism genes were also assessed. Results Monocytes from HIV+ individuals showed increased foam cell formation compared to controls (18.9% vs 0% respectively, p=0.004) and serum from virologically suppressed HIV+ individuals potentiated foam cell formation by monocytes from both uninfected and HIV+ donors. Plasma TNF levels were increased in HIV+ vs control donors (5.9 vs 3.5 pg/ml, p=0.02) and foam cell formation was inhibited by blocking antibodies to TNF receptors, suggesting a direct effect on monocyte differentiation to foam cells. Monocytes from virologically suppressed HIV+ donors showed impaired cholesterol efflux and decreased expression of key genes regulating cholesterol metabolism, including the cholesterol transporter ABCA1 (p=0.02). Conclusions Monocytes from HIV+ individuals show impaired cholesterol efflux and are primed for foam cell formation following trans-endothelial migration. Factors present in HIV+ serum, including elevated TNF levels, further enhance foam cell formation. The pro-atherogenic phenotype of monocytes persists in virologically suppressed HIV+ individuals and may contribute mechanistically to increased atherosclerosis in this population. PMID:26244384

Ex vivo foam cell formation is enhanced in monocytes from older individuals by both extrinsic and intrinsic mechanisms.

PubMed

Angelovich, Thomas A; Shi, Margaret D Y; Zhou, Jingling; Maisa, Anna; Hearps, Anna C; Jaworowski, Anthony

2016-07-01

Aging is the strongest predictor of cardiovascular diseases such as atherosclerosis, which are the leading causes of morbidity and mortality in elderly men. Monocytes play an important role in atherosclerosis by differentiating into foam cells (lipid-laden macrophages) and producing atherogenic proinflammatory cytokines. Monocytes from the elderly have an inflammatory phenotype that may promote atherosclerotic plaque development; here we examined whether they are more atherogenic than those from younger individuals. Using an in vitro model of monocyte transmigration and foam cell formation, monocytes from older men (median age [range]: 75 [58-85] years, n=20) formed foam cells more readily than those of younger men (32 [23-46] years, n=20) (P<0.003) following transmigration across a TNF-activated endothelial monolayer. Compared to young men, monocytes from the elderly had impaired cholesterol efflux and lower expression of regulators of cholesterol transport and metabolism. Foam cell formation was enhanced by soluble factors in serum from older men, but did not correlate with plasma lipid levels. Of the three subsets, intermediate monocytes formed the most foam cells. Therefore, both cellular changes to monocytes and soluble plasma factors in older men primes monocytes for foam cell formation following transendothelial migration, which may contribute to enhanced atherosclerosis in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

Generation of novel bone forming cells (monoosteophils) from the cathelicidin-derived peptide LL-37 treated monocytes.

PubMed

Zhang, Zhifang; Shively, John E

2010-11-15

Bone generation and maintenance involve osteoblasts, osteoclasts, and osteocytes which originate from unique precursors and rely on key growth factors for differentiation. However, an incomplete understanding of bone forming cells during wound healing has led to an unfilled clinical need such as nonunion of bone fractures. Since circulating monocytes are often recruited to sites of injury and may differentiate into various cell types including osteoclasts, we investigated the possibility that circulating monocytes in the context of tissue injury may also contribute to bone repair. In particular, we hypothesized that LL-37 (produced from hCAP-18, cathelicidin), which recruits circulating monocytes during injury, may play a role in bone repair. Treatment of monocytes from blood with LL-37 for 6 days resulted in their differentiation to large adherent cells. Growth of LL-37-differentiated monocytes on osteologic discs reveals bone-like nodule formation by scanning electron microscopy (SEM). In vivo transplantation studies in NOD/SCID mice show that LL-37-differentiated monocytes form bone-like structures similar to endochondral bone formation. Importantly, LL-37-differentiated monocytes are distinct from conventional monocyte-derived osteoclasts, macrophages, and dendritic cells and do not express markers of the mesenchymal stem cells (MSC) lineage, distinguishing them from the conventional precursors of osteoblasts. Furthermore, LL-37 differentiated monocytes express intracellular proteins of both the osteoblast and osteoclast lineage including osteocalcin (OC), osteonectin (ON), bone sialoprotein II (BSP II), osteopontin (OP), RANK, RANKL, MMP-9, tartrate resistant acid phosphatase (TRAP), and cathepsin K (CK). Blood derived monocytes treated with LL-37 can be differentiated into a novel bone forming cell that functions both in vitro and in vivo. We propose the name monoosteophil to indicate their monocyte derived lineage and their bone forming phenotype. These cells may have wide ranging implications in the clinic including repair of broken bones and treatment of osteoporosis.

Subcellular localization of Mitf in monocytic cells.

PubMed

Lu, Ssu-Yi; Wan, Hsiao-Ching; Li, Mengtao; Lin, Yi-Ling

2010-06-01

Microphthalmia-associated transcription factor (Mitf) is a transcription factor that plays an important role in regulating the development of several cell lineages. The subcellular localization of Mitf is dynamic and is associated with its transcription activity. In this study, we examined factors that affect its subcellular localization in cells derived from the monocytic lineage since Mitf is present abundantly in these cells. We identified a domain encoded by Mitf exon 1B1b to be important for Mitf to commute between the cytoplasm and the nucleus. Deletion of this domain disrupts the shuttling of Mitf to the cytoplasm and results in its retention in the nucleus. M-CSF and RANKL both induce nuclear translocation of Mitf. We showed that Mitf nuclear transport is greatly influenced by ratio of M-CSF/Mitf protein expression. In addition, cell attachment to a solid surface also is needed for the nuclear transport of Mitf.

Differential effects of HIV transmission from monocyte-derived dendritic cells vs. monocytes to IL-17+CD4+ T cells

PubMed Central

Mitsuki, Yu-ya; Tuen, Michael; Hioe, Catarina E.

2017-01-01

HIV infection leads to CD4 helper T cell (Th) loss, but not all Th cells are equally depleted. The contribution of other immune cells in the Th depletion also remains unclear. This study investigates HIV transmission from monocyte-derived dendritic cells (MDDCs) vs. monocytes to Th17 and Th1 cells using an allogeneic coculture model. The addition of HIV to MDDCs increased the expression of the negative regulatory molecule PD-L1 and decreased the expression of the activation markers HLA-DR and CD86, whereas the virus up-regulated HLA-DR and CD86, but not PD-L1, on monocytes. Coculturing of CD4+ T cells with MDDCs pretreated with HIV led to the decline of Th17, but not Th1, responses. In contrast, pretreatment of monocytes with HIV increased Th17 without affecting Th1 responses. The enhanced Th17 responses in the cocultures with HIV-treated monocytes were also accompanied by high numbers of virus-infected CD4+ T cells. The Th17 expansion arose from memory CD4+ T cells with minimal contribution from naïve CD4+ T cells. The Th17-enhancing activity was mediated by the HIV envelope and did not require productive virus infection. Comparison of MDDCs and monocytes further showed that, although HIV-treated MDDCs reduced Th proliferation and increased the activation of the apoptosis mediator caspase-3, HIV-treated monocytes enhanced Th proliferation without increasing the active caspase-3 levels. This study indicates the potential role of distinct myeloid cell populations in shaping Th17 responses during HIV infection. PMID:27531931

CXC chemokine ligand 4 (CXCL4) down-regulates CC chemokine receptor expression on human monocytes.

PubMed

Schwartzkopff, Franziska; Petersen, Frank; Grimm, Tobias Alexander; Brandt, Ernst

2012-02-01

During acute inflammation, monocytes are essential in abolishing invading micro-organisms and encouraging wound healing. Recruitment by CC chemokines is an important step in targeting monocytes to the inflamed tissue. However, cell surface expression of the corresponding chemokine receptors is subject to regulation by various endogenous stimuli which so far have not been comprehensively identified. We report that the platelet-derived CXC chemokine ligand 4 (CXCL4), a known activator of human monocytes, induces down-regulation of CC chemokine receptors (CCR) 1, -2, and -5, resulting in drastic impairment of monocyte chemotactic migration towards cognate CC chemokine ligands (CCL) for these receptors. Interestingly, CXCL4-mediated down-regulation of CCR1, CCR2 and CCR5 was strongly dependent on the chemokine's ability to stimulate autocrine/paracrine release of TNF-α. In turn, TNF-α induced the secretion CCL3 and CCL4, two chemokines selective for CCR1 and CCR5, while the secretion of CCR2-ligand CCL2 was TNF-α-independent. Culture supernatants of CXCL4-stimulated monocytes as well as chemokine-enriched preparations thereof reproduced CXCL4-induced CCR down-regulation. In conclusion, CXCL4 may act as a selective regulator of monocyte migration by stimulating the release of autocrine, receptor-desensitizing chemokine ligands. Our results stress a co-ordinating role for CXCL4 in the cross-talk between platelets and monocytes during early inflammation.

A dual positive and negative regulation of monocyte activation by leukocyte Ig-like receptor B4 depends on the position of the tyrosine residues in its ITIMs.

PubMed

Park, Mijeong; Liu, Robert W; An, Hongyan; Geczy, Carolyn L; Thomas, Paul S; Tedla, Nicodemus

2017-05-01

The leukocyte Ig-like receptor B4 (LILRB4) is an inhibitory cell surface receptor, primarily expressed on mono-myeloid cells. It contains 2 C-type Ig-like extracellular domains and a long cytoplasmic domain that contains three intracellular immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Data suggest that LILRB4 suppresses Fc receptor-dependent monocyte functions via its ITIMs, but relative contributions of the three ITIMs are not characterised. To address this, tyrosine (Tyr) residues at positions 337, 389 and 419 were single, double or triple mutated to phenylalanine and stably transfected into a human monocytic cell line, THP-1. Intact Tyr 389 was sufficient to maximally inhibit FcγRI-mediated TNF-α production in THP-1 cells, but, paradoxically, Tyr 337 significantly enhanced TNF-α production. In contrast, bactericidal activity was significantly enhanced in mutants containing Tyr 419 , while Tyr 337 markedly inhibited bacteria killing. Taken together, these results indicate that LILRB4 might have dual inhibitory and activating functions, depending on the position of the functional tyrosine residues in its ITIMs and/or the nature of the stimuli.

Autonomous TNF is critical for in vivo monocyte survival in steady state and inflammation

PubMed Central

Wolf, Yochai; Shemer, Anat; Polonsky, Michal; Gross, Mor; Mildner, Alexander; David, Eyal; Amit, Ido; Heikenwalder, Mathias; Nedospasov, Sergei; Prinz, Marco; Friedman, Nir

2017-01-01

Monocytes are circulating mononuclear phagocytes, poised to extravasate to sites of inflammation and differentiate into monocyte-derived macrophages and dendritic cells. Tumor necrosis factor (TNF) and its receptors are up-regulated during monopoiesis and expressed by circulating monocytes, as well as effector monocytes infiltrating certain sites of inflammation, such as the spinal cord, during experimental autoimmune encephalomyelitis (EAE). In this study, using competitive in vitro and in vivo assays, we show that monocytes deficient for TNF or TNF receptors are outcompeted by their wild-type counterpart. Moreover, monocyte-autonomous TNF is critical for the function of these cells, as TNF ablation in monocytes/macrophages, but not in microglia, delayed the onset of EAE in challenged animals and was associated with reduced acute spinal cord infiltration of Ly6Chi effector monocytes. Collectively, our data reveal a previously unappreciated critical cell-autonomous role of TNF on monocytes for their survival, maintenance, and function. PMID:28330904

MCSF expression is induced in healing myocardial infarcts and may regulate monocyte and endothelial cell phenotype.

PubMed

Frangogiannis, Nikolaos G; Mendoza, Leonardo H; Ren, Guofeng; Akrivakis, Spyridon; Jackson, Peggy L; Michael, Lloyd H; Smith, C Wayne; Entman, Mark L

2003-08-01

Myocardial infarction is associated with the rapid induction of mononuclear cell chemoattractants that promote monocyte infiltration into the injured area. Monocyte-to-macrophage differentiation and macrophage proliferation allow a long survival of monocytic cells, critical for effective healing of the infarct. In a canine infarction-reperfusion model, newly recruited myeloid leukocytes were markedly augmented during early reperfusion (5-72 h). By 7 days, the number of newly recruited myeloid cells was reduced, and the majority of the inflammatory cells remaining in the infarct were mature macrophages. Macrophage colony-stimulating factor (MCSF) is known to facilitate monocyte survival, monocyte-to-macrophage conversion, and macrophage proliferation. We demonstrated marked induction of MCSF mRNA in ischemic segments persisting for at least 5 days after reperfusion. MCSF expression was predominantly localized to mature macrophages infiltrating the infarcted myocardium; the expression of the MCSF receptor, c-Fms, a protein with tyrosine kinase activity, was found in these macrophages but was also observed in a subset of microvessels within the infarct. Many infarct macrophages expressed proliferating cell nuclear antigen, a marker of proliferative activity. In vitro MCSF induced monocyte chemoattractant protein-1 synthesis in canine venous endothelial cells. MCSF-induced endothelial monocyte chemoattractant protein-1 upregulation was inhibited by herbimycin A, a tyrosine kinase inhibitor, and by LY-294002, a phosphatidylinositol 3'-kinase inhibitor. We suggest that upregulation of MCSF in the infarcted myocardium may have an active role in healing not only through its effects on cells of monocyte/macrophage lineage, but also by regulating endothelial cell chemokine expression.

UVB radiation and human monocyte accessory function: Differential effects on pre-mitotic events in T-cell activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krutmann, J.K.; Kammer, G.M.; Toossi, Z.

Purified T lymphocytes fail to proliferate in response to antigenic and mitogenic stimuli when cultured in the presence of accessory cells that have been exposed in vitro to sublethal doses of UVB radiation. Because proliferation represents a final stage in the T-cell activation process, the present study was conducted to determine whether T cells were able to progress through any of the pre-mitotic stages when UVB-irradiated monocytes were used as model accessory cells. In these experiments, monoclonal anti-CD3 antibodies were employed as the mitogenic stimulus. Culture of T cells with UVB-irradiated monocytes did allow the T cells to undergo anmore » increase in intracellular free calcium, which is one of the first steps in the activation sequence. The T cells expressed interleukin-2 receptors, although at a reduced level. However, T cells failed to produce interleukin-2 above background levels when they were placed in culture with monocytes exposed to UVB doses as low as 50 J/m2. Incubation of T cells with UVB-irradiated monocytes did not affect the subsequent capacity of T cells to proliferate, since they developed a normal proliferative response in secondary culture when restimulated with anti-CD3 antibodies and unirradiated monocytes. These studies indicate that T lymphocytes become partially activated when cultured with UVB-irradiated monocytes and mitogenic anti-CD3 monoclonal antibodies. In addition, they suggest that interleukin-2 production is the T-cell activation step most sensitive to inhibition when UVB-irradiated monocytes are employed as accessory cells.« less

Labeling monocytes with gold nanoparticles to track their recruitment in atherosclerosis with computed tomography

PubMed Central

Chhour, Peter; Naha, Pratap C.; O’Neill, Sean M.; Litt, Harold I.; Reilly, Muredach P.; Ferrari, Victor A.; Cormode, David P.

2016-01-01

Monocytes are actively recruited from the circulation into developing atherosclerotic plaques. In the plaque, monocytes differentiate into macrophages and eventually form foam cells. Continued accumulation of foam cells can lead to plaque rupture and subsequent myocardial infarction. X-ray computed tomography (CT) is the best modality to image the coronary arteries non-invasively, therefore we have sought to track the accumulation of monocytes into atherosclerotic plaques using CT. Gold nanoparticles were synthesized and stabilized with a variety of ligands. Select formulations were incubated with an immortalized monocyte cell line in vitro and evaluated for cytotoxicity, effects on cytokine release, and cell uptake. These data identified a lead formulation, 11-MUDA capped gold nanoparticles, to test for labeling primary monocytes. The formulation did not the affect the viability or cytokine release of primary monocytes and was highly taken up by these cells. Gold labeled primary monocytes were injected into apolipoprotein E deficient mice kept on Western diet for 10 weeks. Imaging was done with a microCT scanner. A significant increase in attenuation was measured in the aorta of mice receiving the gold labeled cells as compared to control animals. Following the experiment, the biodistribution of gold was evaluated in major organs. Additionally, plaques were sectioned and examined with electron microscopy. The results showed that gold nanoparticles were present inside monocytes located within plaques. This study demonstrates the feasibility of using gold nanoparticles as effective cell labeling contrast agents for non-invasive imaging of monocyte accumulation within plaques with CT. PMID:26914700

Labeling monocytes with gold nanoparticles to track their recruitment in atherosclerosis with computed tomography.

PubMed

Chhour, Peter; Naha, Pratap C; O'Neill, Sean M; Litt, Harold I; Reilly, Muredach P; Ferrari, Victor A; Cormode, David P

2016-05-01

Monocytes are actively recruited from the circulation into developing atherosclerotic plaques. In the plaque, monocytes differentiate into macrophages and eventually form foam cells. Continued accumulation of foam cells can lead to plaque rupture and subsequent myocardial infarction. X-ray computed tomography (CT) is the best modality to image the coronary arteries non-invasively, therefore we have sought to track the accumulation of monocytes into atherosclerotic plaques using CT. Gold nanoparticles were synthesized and stabilized with a variety of ligands. Select formulations were incubated with an immortalized monocyte cell line in vitro and evaluated for cytotoxicity, effects on cytokine release, and cell uptake. These data identified a lead formulation, 11-MUDA capped gold nanoparticles, to test for labeling primary monocytes. The formulation did not the affect the viability or cytokine release of primary monocytes and was highly taken up by these cells. Gold labeled primary monocytes were injected into apolipoprotein E deficient mice kept on Western diet for 10 weeks. Imaging was done with a microCT scanner. A significant increase in attenuation was measured in the aorta of mice receiving the gold labeled cells as compared to control animals. Following the experiment, the biodistribution of gold was evaluated in major organs. Additionally, plaques were sectioned and examined with electron microscopy. The results showed that gold nanoparticles were present inside monocytes located within plaques. This study demonstrates the feasibility of using gold nanoparticles as effective cell labeling contrast agents for non-invasive imaging of monocyte accumulation within plaques with CT. Copyright © 2016 Elsevier Ltd. All rights reserved.

The chemiluminescent response of human monocytes to red cells sensitized with monoclonal anti-Rh(D) antibodies.

PubMed

Hadley, A G; Kumpel, B M; Merry, A H

1988-01-01

Luminol-enhanced chemiluminescence (CL) was used to assess the metabolic response of human monocytes to red cells sensitized with known amounts of anti-Rh(D). Monoclonal antibodies were used to facilitate a comparison between the functional activities of IgG1 and IgG3 subclasses. The detection of CL provided a simple, rapid and semi-quantitative means of measuring monocyte response to sensitized red cells (IgG-RBC). Monocyte response to IgG3-RBC was quantitatively greater, more rapid and less susceptible to inhibition by fluid phase IgG than monocyte response to IgG1-RBC. The minimum levels of sensitization required to elicit CL from monocytes were approximately 2500 IgG3 molecules per red cell, or approximately 5000 IgG1 molecules per cell.

ALV-J infection induces chicken monocyte death accompanied with the production of IL-1β and IL-18.

PubMed

Dai, Manman; Feng, Min; Xie, Tingting; Li, Yuanfang; Ruan, Zhuohao; Shi, Meiqing; Liao, Ming; Zhang, Xiquan

2017-11-21

Immunosuppression induced by avian leukosis virus subgroup J (ALV-J) causes serious reproduction problems and secondary infections in chickens. Given that monocytes are important precursors of immune cells including macrophages and dendritic cells, we investigated the fate of chicken monocytes after ALV-J infection. Our results indicated that most monocytes infected with ALV-J including field or laboratory strains could not successfully differentiate into macrophages due to cells death. And cells death was dependent upon viral titer and accompanied with increased IL-1β and IL-18 mRNA levels. In addition, ALV-J infection up-regulated caspase-1 and caspase-3 activity in monocytes. Collectively, we found that ALV-J could cause cell death in chicken monocytes, especially pyroptosis, which may be a significant reason for ALV-J induced immunosuppression.

ALV-J infection induces chicken monocyte death accompanied with the production of IL-1β and IL-18

PubMed Central

Dai, Manman; Feng, Min; Xie, Tingting; Li, Yuanfang; Ruan, Zhuohao; Shi, Meiqing; Liao, Ming; Zhang, Xiquan

2017-01-01

Immunosuppression induced by avian leukosis virus subgroup J (ALV-J) causes serious reproduction problems and secondary infections in chickens. Given that monocytes are important precursors of immune cells including macrophages and dendritic cells, we investigated the fate of chicken monocytes after ALV-J infection. Our results indicated that most monocytes infected with ALV-J including field or laboratory strains could not successfully differentiate into macrophages due to cells death. And cells death was dependent upon viral titer and accompanied with increased IL-1β and IL-18 mRNA levels. In addition, ALV-J infection up-regulated caspase-1 and caspase-3 activity in monocytes. Collectively, we found that ALV-J could cause cell death in chicken monocytes, especially pyroptosis, which may be a significant reason for ALV-J induced immunosuppression. PMID:29245947

C/EBPepsilon directs granulocytic-vs-monocytic lineage determination and confers chemotactic function via Hlx.

PubMed

Halene, Stephanie; Gaines, Peter; Sun, Hong; Zibello, Theresa; Lin, Sharon; Khanna-Gupta, Arati; Williams, Simon C; Perkins, Archibald; Krause, Diane; Berliner, Nancy

2010-02-01

Mutations in the CCAAT enhancer binding protein epsilon (C/EBPepsilon) gene have been identified in the cells of patients with neutrophil specific granule deficiency, a rare congenital disorder marked by recurrent bacterial infections. Their neutrophils, in addition to lacking specific granules required for normal respiratory burst activity, also lack normal phagocytosis and chemotaxis. Although the specific granule deficiency phenotype has been replicated in C/EBPepsilon(-/-) (knockout [KO]) mice, the mechanisms by which C/EBPepsilon mutations act to decrease neutrophil function are not entirely clear. In order to determine the role of C/EBPepsilon in neutrophil differentiation and migration, we generated immortalized progenitor cell lines from C/EBPepsilon KO and wild-type mice and performed expression and flow cytometric analysis and functional studies. Expression of lineage-specific cell surface antigens on our in vitro differentiated cell lines revealed persistent expression of monocytic markers on KO granulocytes. We verified this in primary murine peripheral blood and bone marrow cells. In addition, KO bone marrow had an increase in immature myeloid precursors at the common myeloid progenitor and granulocyte/monocyte progenitor levels, suggesting a critical role for C/EBPepsilon not only in granulocyte maturation beyond the promyelocyte stage, but also in the monocyte/granulocyte lineage decision. We found that restoration of Hlx (H2.0-like homeo box 1) expression, which was decreased in C/EBPepsilon KO cells, rescued chemotaxis, but not the other defects of C/EBPepsilon KO neutrophils. We show two new regulatory functions of C/EBPepsilon in myelopoiesis: in the absence of C/EBPepsilon, there is not only incomplete differentiation of granulocytes, but myelopoiesis is disrupted with the appearance of an intermediate cell type with monocyte and granulocyte features, and the neutrophils have abnormal chemotaxis. Restoration of expression of Hlx provides partial recovery of function; it has no effect on neutrophil maturation, but can completely ameliorate the chemotaxis defect in C/EBPepsilon KO cells. Copyright 2010 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

CD16+ monocytes control T-cell subset development in immune thrombocytopenia

PubMed Central

Zhong, Hui; Bao, Weili; Li, Xiaojuan; Miller, Allison; Seery, Caroline; Haq, Naznin; Bussel, James

2012-01-01

Immune thrombocytopenia (ITP) results from decreased platelet production and accelerated platelet destruction. Impaired CD4+ regulatory T-cell (Treg) compartment and skewed Th1 and possibly Th17 responses have been described in ITP patients. The trigger for aberrant T-cell polarization remains unknown. Because monocytes have a critical role in development and polarization of T-cell subsets, we explored the contribution of monocyte subsets in control of Treg and Th development in patients with ITP. Unlike circulating classic CD14hiCD16− subpopulation, the CD16+ monocyte subset was expanded in ITP patients with low platelet counts on thrombopoietic agents and positively correlated with T-cell CD4+IFN-γ+ levels, but negatively with circulating CD4+CD25hiFoxp3+ and IL-17+ Th cells. Using a coculture model, we found that CD16+ ITP monocytes promoted the expansion of IFN-γ+CD4+ cells and concomitantly inhibited the proliferation of Tregs and IL-17+ Th cells. Th-1–polarizing cytokine IL-12, secreted after direct contact of patient T-cell and CD16+ monocytes, was responsible for the inhibitory effect on Treg and IL-17+CD4+ cell proliferation. Our findings are consistent with ITP CD16+ monocytes promoting Th1 development, which in turn negatively regulates IL-17 and Treg induction. This underscores the critical role of CD16+ monocytes in the generation of potentially pathogenic Th responses in ITP. PMID:22915651

Macrolide Antibiotics Improve Phagocytic Capacity and Reduce Inflammation In Sulfur Mustard-Exposed Monocytes

DTIC Science & Technology

2008-12-01

phagocytotic function and on inflammatory cytokines/mediators production in vitro using SM-exposed monocyte THP - 1 cells. Using flow cytometry we found...in vitro using SM-exposed monocyte THP - 1 cells. 2. MATERIALS AND METHODS 2.1 Reagents Sulfur mustard (2,2’-dichlorodiethyl sulfide; 4 mM) was...monocyte THP - 1 cells were obtained from ATCC (Manassas, VA). Cells were grown as suspension in the optimized media as formulated by the manufacturer and

Effect of Native and Minimally Modified Low-density Lipoprotein on the Activation of Monocyte Subsets.

PubMed

Blanco-Favela, Francisco; Espinosa-Luna, José Esteban; Chávez-Rueda, Adriana Karina; Madrid-Miller, Alejandra; Chávez-Sánchez, Luis

2017-07-01

In atherosclerosis, monocytes are essential and secrete pro-inflammatory cytokines in response to modified low-density lipoprotein (LDL). Human CD14 ++ CD16 - , CD14 ++ CD16 + and CD14 + CD16 ++ monocytes produce different cytokines. The objective of this research was to determine the number of monocyte subsets positives to cytokines in response to native (nLDL) and minimally modified LDL (mmLDL). Human monocytes from healthy individuals were purified by negative selection and were stimulated with nLDL, mmLDL or LPS. Subsequently, human total monocytes were incubated with monoclonal antibodies specific for CD14 or both CD14 and CD16 to characterize total monocytes and monocyte subsets and with antibodies specific to anti-tumor necrosis factor (TNF)-α, anti-interleukin (IL)-6 and anti-IL-10. The number of cells positive for cytokines was determined and cells cultured with nLDL, mmLDL and LPS were compared with cells cultured only with culture medium. We found that nLDL does not induce in the total monocyte population or in the three monocyte subsets positives to cytokines. MmLDL induced in total monocytes positives to TNF-α and IL-6 as well as in both CD14 ++ CD16 + and CD14 + CD16 ++ and in CD14 ++ CD16 + monocytes, respectively. Moreover, total monocytes and the three monocyte subsets expressed few amounts of cells positives to IL-10 in response to mmLDL. Our study demonstrated that nLDL did not induce cells positives to cytokines and that the CD14 ++ CD16 + and CD14 + CD16 ++ monocyte subsets could be the main sources of TNF-α and IL-6, respectively, in response to mmLDL, which promotes the development and progression of atherosclerotic plaque. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

Comparative analysis of signature genes in PRRSV-infected porcine monocyte-derived cells at differential activation statuses

USDA-ARS?s Scientific Manuscript database

Activation statuses of monocytic cells are critically important for antiviral immunity. Devastating viruses like porcine reproductive and respiratory syndrome virus (PRRSV) are capable of directly infecting these cells, subverting host immunity. Monocyte-derived DCs (mDCs) are major target cells in ...

Vesicular Location and Transport of S100A8 and S100A9 Proteins in Monocytoid Cells

PubMed Central

Chakraborty, Paramita; Bjork, Per; Källberg, Eva; Olsson, Anders; Riva, Matteo; Mörgelin, Matthias; Liberg, David; Ivars, Fredrik; Leanderson, Tomas

2015-01-01

We show here, by using surface biotinylation, followed by Western blotting or surface plasmon resonance analysis, that very low levels of S100A8 and/or S100A9 can be detected on the surface of THP-1 cells or freshly isolated human monocytes. This was supported by immune-electron microscopy where we observed membrane-associated expression of the proteins restricted to small patches. By using confocal microscopy we could determine that S100A8 and S100A9 protein in THP-1 cells or freshly isolated human monocytes was mostly present in vesicular structures. This finding was confirmed using immune-electron microscopy. Subcellular fractionation and confocal microscopy showed that these vesicular structures are mainly early endosomes and endolysosomes. Our subsequent studies showed that accumulation of S100A8 and S100A9 in the endolysosomal compartment is associated with induction of their release from the cells. Furthermore, an inhibitor of lysosomal activity could modulate the release of S100A8 and S100A9 in the extracellular milieu. Our current results suggest that the S100A8 and S100A9 proteins are primarily associated with certain kinds of cytosolic vesicles and may be secreted via an endolysosomal pathway. PMID:26661255

Basic surface properties of mononuclear cells from Didelphis marsupialis.

PubMed

Nacife, V P; de Meirelles, M de N; Silva Filho, F C

1998-01-01

The electrostatic surface charge and surface tension of mononuclear cells/monocytes obtained from young and adult marsupials (Didelphis marsupialis) were investigated by using cationized ferritin and colloidal iron hydroxyde, whole cell electrophoresis, and measurements of contact angles. Anionic sites were found distributed throughout the entire investigated cell surfaces. The results revealed that the anionic character of the cells is given by electrostatic charges corresponding to -18.8 mV (cells from young animals) and -29.3 mV (cells from adult animals). The surface electrostatic charge decreased from 10 to 65.2% after treatment of the cells with each one of trypsin, neuraminidase and phospholipase C. The hydrophobic nature of the mononuclear cell surfaces studied by using the contact angle method revealed that both young and adult cells possess cell surfaces of high hidrofilicity since the angles formed with drops of saline water were 42.5 degrees and 40.8 degrees, respectively. Treatment of the cells with trypsin or neuraminidase rendered their surfaces more hydrophobic, suggesting that sialic acid-containing glycoproteins are responsible for most of the hydrophilicity observed in the mononuclear cell surfaces from D. marsupialis.

Human Monocytes in the Presence of Interferons Alpha2a and Gamma Are Potent Killers of Serous Ovarian Cancer Cell Lines in Combination with Paclitaxel and Carboplatin

PubMed Central

Johnson, Chase L.; Zoon, Kathryn C.

2015-01-01

Interferons (IFNs) play an important role in immune surveillance of tumors; however, their efficacy in the treatment of malignancies has been limited. Monocytes are mononuclear phagocytes that are critical to the generation of an innate immune response to tumors. The authors and others have shown that treatment of tumor cell lines in vitro and in vivo with human monocytes primed with type I and type II IFNs results in killing. We now expand on this work, in an extended panel of ovarian cancer cell lines. In this study, we hypothesized that there would be variable sensitivity amongst cell lines to the killing properties of monocytes and IFNs. To this end, we explored the interactions of IFN primed monocytes in conjunction with the standard of therapy for ovarian cancer, taxane, and platinum-based chemotherapeutics. Using 6 ovarian cancer cell lines, we demonstrated that there is variation from cell line to cell line in the ability of IFN-α2a and IFN-γ primed monocytes to synergistically kill target tumor cells, and further, there is an additive killing effect when target cells are treated with both IFN primed monocytes and chemotherapy. PMID:25068849

Immune system alteration in response to two consecutive soccer games.

PubMed

Malm, C; Ekblom, O; Ekblom, B

2004-02-01

Changes in leucocyte and monocyte subpopulations were investigated in 10 elite male soccer players aged 16-19 years. The purpose was to perform a descriptive study of immunological alterations in elite soccer players in response to two consecutive games separated by 20 h. It was hypothesized that in response to two games the players would show signs of short-term immunosuppression. Blood samples were taken before the first soccer game, immediately after the second game and after 6, 24, 48 and 72 h. Cell surface antigens, testosterone and cortisol were investigated. During the first 6 h after the second game there was a significant increase in number of circulating neutrophils, mature (CD20+ CD5+) B cells and CD4/CD8 ratio. A significant decrease was observed in the number of natural killer (NK) cells, monocytes and adhesion on lymphocytes and monocytes. In a delayed phase, 48 h after the second game the expression of both adhesion and signalling molecules increased on lymphocytes and monocytes. Changes in adhesion and signalling molecules at 48 h correlated negatively to the subjects VO2max, suggesting larger immunological response to similar exercise in subjects with lower aerobic exercise capacity. In response to competitive soccer exercise some immunological variables are enhanced while others are depressed. Observed changes may serve a purpose in adaptation to exercise by signalling via adhesion.

Phenotyping and susceptibility of established porcine cells lines to African Swine Fever Virus infection and viral production.

PubMed

Sánchez, Elena G; Riera, Elena; Nogal, Marisa; Gallardo, Carmina; Fernández, Paloma; Bello-Morales, Raquel; López-Guerrero, José Antonio; Chitko-McKown, Carol G; Richt, Jürgen A; Revilla, Yolanda

2017-09-04

African swine fever virus (ASFV) is a highly pathogenic, double-stranded DNA virus with a marked tropism for cells of the monocyte-macrophage lineage, affecting swine species and provoking severe economic losses and health threats. In the present study, four established porcine cell lines, IPAM-WT, IPAM-CD163, C∆2+ and WSL, were compared to porcine alveolar macrophage (PAM) in terms of surface marker phenotype, susceptibility to ASFV infection and virus production. The virulent ASFV Armenia/07, E70 or the naturally attenuated NHV/P68 strains were used as viral models. Cells expressed only low levels of specific receptors linked to the monocyte/macrophage lineage, with low levels of infection overall, with the exception of WSL, which showed more efficient production of strain NHV/P68 but not of strains E70 and Armenia/07.

Altered monocyte and fibrocyte phenotype and function in scleroderma interstitial lung disease: reversal by caveolin-1 scaffolding domain peptide.

PubMed

Tourkina, Elena; Bonner, Michael; Oates, James; Hofbauer, Ann; Richard, Mathieu; Znoyko, Sergei; Visconti, Richard P; Zhang, Jing; Hatfield, Corey M; Silver, Richard M; Hoffman, Stanley

2011-07-01

Interstitial lung disease (ILD) is a major cause of morbidity and mortality in scleroderma (systemic sclerosis, or SSc). Fibrocytes are a monocyte-derived cell population implicated in the pathogenesis of fibrosing disorders. Given the recently recognized importance of caveolin-1 in regulating function and signaling in SSc monocytes, in the present study we examined the role of caveolin-1 in the migration and/or trafficking and phenotype of monocytes and fibrocytes in fibrotic lung disease in human patients and an animal model. These studies fill a gap in our understanding of how monocytes and fibrocytes contribute to SSc-ILD pathology. We found that C-X-C chemokine receptor type 4-positive (CXCR4+)/collagen I-positive (ColI+), CD34+/ColI+ and CD45+/ColI+ cells are present in SSc-ILD lungs, but not in control lungs, with CXCR4+ cells being most prevalent. Expression of CXCR4 and its ligand, stromal cell-derived factor 1 (CXCL12), are also highly upregulated in SSc-ILD lung tissue. SSc monocytes, which lack caveolin-1 and therefore overexpress CXCR4, exhibit almost sevenfold increased migration toward CXCL12 compared to control monocytes. Restoration of caveolin-1 function by administering the caveolin scaffolding domain (CSD) peptide reverses this hypermigration. Similarly, transforming growth factor β-treated normal monocytes lose caveolin-1, overexpress CXCR4 and exhibit 15-fold increased monocyte migration that is CSD peptide-sensitive. SSc monocytes exhibit a different phenotype than normal monocytes, expressing high levels of ColI, CD14 and CD34. Because ColI+/CD14+ cells are prevalent in SSc blood, we looked for such cells in lung tissue and confirmed their presence in SSc-ILD lungs but not in normal lungs. Finally, in the bleomycin model of lung fibrosis, we show that CSD peptide diminishes fibrocyte accumulation in the lungs. Our results suggest that low caveolin-1 in SSc monocytes contributes to ILD via effects on cell migration and phenotype and that the hyperaccumulation of fibrocytes in SSc-ILD may result from the altered phenotype and migratory activity of their monocyte precursors.

Altered monocyte and fibrocyte phenotype and function in scleroderma interstitial lung disease: reversal by caveolin-1 scaffolding domain peptide

PubMed Central

2011-01-01

Interstitial lung disease (ILD) is a major cause of morbidity and mortality in scleroderma (systemic sclerosis, or SSc). Fibrocytes are a monocyte-derived cell population implicated in the pathogenesis of fibrosing disorders. Given the recently recognized importance of caveolin-1 in regulating function and signaling in SSc monocytes, in the present study we examined the role of caveolin-1 in the migration and/or trafficking and phenotype of monocytes and fibrocytes in fibrotic lung disease in human patients and an animal model. These studies fill a gap in our understanding of how monocytes and fibrocytes contribute to SSc-ILD pathology. We found that C-X-C chemokine receptor type 4-positive (CXCR4+)/collagen I-positive (ColI+), CD34+/ColI+ and CD45+/ColI+ cells are present in SSc-ILD lungs, but not in control lungs, with CXCR4+ cells being most prevalent. Expression of CXCR4 and its ligand, stromal cell-derived factor 1 (CXCL12), are also highly upregulated in SSc-ILD lung tissue. SSc monocytes, which lack caveolin-1 and therefore overexpress CXCR4, exhibit almost sevenfold increased migration toward CXCL12 compared to control monocytes. Restoration of caveolin-1 function by administering the caveolin scaffolding domain (CSD) peptide reverses this hypermigration. Similarly, transforming growth factor β-treated normal monocytes lose caveolin-1, overexpress CXCR4 and exhibit 15-fold increased monocyte migration that is CSD peptide-sensitive. SSc monocytes exhibit a different phenotype than normal monocytes, expressing high levels of ColI, CD14 and CD34. Because ColI+/CD14+ cells are prevalent in SSc blood, we looked for such cells in lung tissue and confirmed their presence in SSc-ILD lungs but not in normal lungs. Finally, in the bleomycin model of lung fibrosis, we show that CSD peptide diminishes fibrocyte accumulation in the lungs. Our results suggest that low caveolin-1 in SSc monocytes contributes to ILD via effects on cell migration and phenotype and that the hyperaccumulation of fibrocytes in SSc-ILD may result from the altered phenotype and migratory activity of their monocyte precursors. PMID:21722364

Cannabidiol induced a contrasting pro-apoptotic effect between freshly isolated and precultured human monocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Hsin-Ying; Chang, An-Chi; Wang, Chia-Chi

2010-08-01

It has been documented that cannabidiol (CBD) induced apoptosis in a variety of transformed cells, including lymphocytic and monocytic leukemias. In contrast, a differential sensitivity between normal lymphocytes and monocytes to CBD-mediated apoptosis has been reported. The present study investigated the pro-apoptotic effect of CBD on human peripheral monocytes that were either freshly isolated or precultured for 72 h. CBD markedly enhanced apoptosis of freshly isolated monocytes in a time- and concentration-dependent manner, whereas precultured monocytes were insensitive. By comparison, both cells were sensitive to doxorubicin-induced apoptosis. CBD significantly diminished the cellular thiols and glutathione in freshly isolated monocytes. Themore » apoptosis induced by CBD was abrogated in the presence of N-acetyl-{sub L}-cysteine, a precursor of glutathione. In addition, precultured monocytes contained a significantly greater level of glutathione and heme oxygenase-1 (HO-1) compared to the freshly isolated cells. The HO-1 competitive inhibitor zinc protoporphyrin partially but significantly restored the sensitivity of precultured monocytes to CBD-mediated apoptosis. Collectively, our results demonstrated a contrasting pro-apoptotic effect of CBD between precultured and freshly isolated monocytes, which was closely associated with the cellular level of glutathione and the antioxidative capability of the cells.« less

Comparative analysis of signature genes in porcine reproductive and respiratory syndrome virus (PRRSV)-infected porcine monocyte-derived dendritic cells at differential activation statuses

USDA-ARS?s Scientific Manuscript database

Activation statuses of monocytic cells, e.g. monocytes, macrophages and dendritic cells (DCs), are critically important for antiviral immunity. In particular, some devastating viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), are capable of directly infecting these cell...

Dexamethasone enhances agonist induction of tissue factor in monocytes but not in endothelial cells.

PubMed

Bottles, K D; Morrissey, J H

1993-06-01

Stimulation of monocytic cells by inflammatory agents such as bacterial lipopolysaccharide or tumour necrosis factor-alpha leads to the rapid and transient expression of tissue factor, the major cellular initiator of the extrinsic coagulation cascade in both haemostasis and tissue inflammation. In this study we investigated whether the synthetic anti-inflammatory glucocorticoid, dexamethasone, would inhibit agonist induction of tissue factor expression in both monocytes and endothelial cells. Surprisingly, dexamethasone significantly enhanced the induction of tissue factor expression by peripheral blood mononuclear cells and an established monocytic cell line, THP-1, in response to lipopolysaccharide or tumour necrosis factor-alpha. However, unlike monocytic cells, dexamethasone did not enhance agonist induction of tissue factor in endothelial cells. Synergistic enhancement of tissue factor expression by dexamethasone was also reflected in tissue factor mRNA levels in THP-1 cells, but was not the result of improved TF mRNA stability. Synergism between bacterial lipopolysaccharide and glucocorticoid in the induction of monocyte effector function is extremely unusual and may help to explain the variable outcome of glucocorticoid treatment of septic shock.

Rapid Detection of Dendritic Cell and Monocyte Disorders Using CD4 as a Lineage Marker of the Human Peripheral Blood Antigen-Presenting Cell Compartment

PubMed Central

Jardine, Laura; Barge, Dawn; Ames-Draycott, Ashley; Pagan, Sarah; Cookson, Sharon; Spickett, Gavin; Haniffa, Muzlifah; Collin, Matthew; Bigley, Venetia

2013-01-01

Dendritic cells (DCs) and monocytes are critical regulators and effectors of innate and adaptive immune responses. Monocyte expansion has been described in many pathological states while monocyte and DC deficiency syndromes are relatively recent additions to the catalog of human primary immunodeficiency disorders. Clinically applicable screening tests to diagnose and monitor these conditions are lacking. Conventional strategies for identifying human DCs and monocytes have been based on the use of a lineage gate to exclude lymphocytes, thus preventing simultaneous detection of DCs, monocytes, and lymphocyte subsets. Here we demonstrate that CD4 is a reliable lineage marker for the human peripheral blood antigen-presenting cell compartment that can be used to identify DCs and monocytes in parallel with lymphocytes. Based on this principle, simple modification of a standard lymphocyte phenotyping assay permits simultaneous enumeration of four lymphocyte and five DC/monocyte populations from a single sample. This approach is applicable to clinical samples and facilitates the diagnosis of DC and monocyte disorders in a wide range of clinical settings, including genetic deficiency, neoplasia, and inflammation. PMID:24416034

Platelet density per monocyte predicts adverse events in patients after percutaneous coronary intervention.

PubMed

Rutten, Bert; Roest, Mark; McClellan, Elizabeth A; Sels, Jan W; Stubbs, Andrew; Jukema, J Wouter; Doevendans, Pieter A; Waltenberger, Johannes; van Zonneveld, Anton-Jan; Pasterkamp, Gerard; De Groot, Philip G; Hoefer, Imo E

2016-01-01

Monocyte recruitment to damaged endothelium is enhanced by platelet binding to monocytes and contributes to vascular repair. Therefore, we studied whether the number of platelets per monocyte affects the recurrence of adverse events in patients after percutaneous coronary intervention (PCI). Platelet-monocytes complexes with high and low median fluorescence intensities (MFI) of the platelet marker CD42b were isolated using cell sorting. Microscopic analysis revealed that a high platelet marker MFI on monocytes corresponded with a high platelet density per monocyte while a low platelet marker MFI corresponded with a low platelet density per monocyte (3.4 ± 0.7 vs 1.4 ± 0.1 platelets per monocyte, P=0.01). Using real-time video microscopy, we observed increased recruitment of high platelet density monocytes to endothelial cells as compared with low platelet density monocytes (P=0.01). Next, we classified PCI scheduled patients (N=263) into groups with high, medium and low platelet densities per monocyte and assessed the recurrence of adverse events. After multivariate adjustment for potential confounders, we observed a 2.5-fold reduction in the recurrence of adverse events in patients with a high platelet density per monocyte as compared with a low platelet density per monocyte [hazard ratio=0.4 (95% confidence interval, 0.2-0.8), P=0.01]. We show that a high platelet density per monocyte increases monocyte recruitment to endothelial cells and predicts a reduction in the recurrence of adverse events in patients after PCI. These findings may imply that a high platelet density per monocyte protects against recurrence of adverse events.

Oxalate induces mitochondrial dysfunction and disrupts redox homeostasis in a human monocyte derived cell line.

PubMed

Patel, Mikita; Yarlagadda, Vidhush; Adedoyin, Oreoluwa; Saini, Vikram; Assimos, Dean G; Holmes, Ross P; Mitchell, Tanecia

2018-05-01

Monocytes/macrophages are thought to be recruited to the renal interstitium during calcium oxalate (CaOx) kidney stone disease for crystal clearance. Mitochondria play an important role in monocyte function during the immune response. We recently determined that monocytes in patients with CaOx kidney stones have decreased mitochondrial function compared to healthy subjects. The objective of this study was to determine whether oxalate, a major constituent found in CaOx kidney stones, alters cell viability, mitochondrial function, and redox homeostasis in THP-1 cells, a human derived monocyte cell line. THP-1 cells were treated with varying concentrations of CaOx crystals (insoluble form) or sodium oxalate (NaOx; soluble form) for 24h. In addition, the effect of calcium phosphate (CaP) and cystine crystals was tested. CaOx crystals decreased cell viability and induced mitochondrial dysfunction and redox imbalance in THP-1 cells compared to control cells. However, NaOx only caused mitochondrial damage and redox imbalance in THP-1 cells. In contrast, both CaP and cystine crystals did not affect THP-1 cells. Separate experiments showed that elevated oxalate also induced mitochondrial dysfunction in primary monocytes from healthy subjects. These findings suggest that oxalate may play an important role in monocyte mitochondrial dysfunction in CaOx kidney stone disease. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Epstein-Barr virus lytic infection promotes activation of Toll-like receptor 8 innate immune response in systemic sclerosis monocytes.

PubMed

Farina, Antonella; Peruzzi, Giovanna; Lacconi, Valentina; Lenna, Stefania; Quarta, Silvia; Rosato, Edoardo; Vestri, Anna Rita; York, Michael; Dreyfus, David H; Faggioni, Alberto; Morrone, Stefania; Trojanowska, Maria; Farina, G Alessandra

2017-02-28

Monocytes/macrophages are activated in several autoimmune diseases, including systemic sclerosis (scleroderma; SSc), with increased expression of interferon (IFN)-regulatory genes and inflammatory cytokines, suggesting dysregulation of the innate immune response in autoimmunity. In this study, we investigated whether the lytic form of Epstein-Barr virus (EBV) infection (infectious EBV) is present in scleroderma monocytes and contributes to their activation in SSc. Monocytes were isolated from peripheral blood mononuclear cells (PBMCs) depleted of the CD19+ cell fraction, using CD14/CD16 negative-depletion. Circulating monocytes from SSc and healthy donors (HDs) were infected with EBV. Gene expression of innate immune mediators were evaluated in EBV-infected monocytes from SSc and HDs. Involvement of Toll-like receptor (TLR)8 in viral-mediated TLR8 response was investigated by comparing the TLR8 expression induced by infectious EBV to the expression stimulated by CL075/TLR8/agonist-ligand in the presence of TLR8 inhibitor in THP-1 cells. Infectious EBV strongly induced TLR8 expression in infected SSc and HD monocytes in vitro. Markers of activated monocytes, such as IFN-regulated genes and chemokines, were upregulated in SSc- and HD-EBV-infected monocytes. Inhibiting TLR8 expression reduced virally induced TLR8 in THP-1 infected cells, demonstrating that innate immune activation by infectious EBV is partially dependent on TLR8. Viral mRNA and proteins were detected in freshly isolated SSc monocytes. Microarray analysis substantiated the evidence of an increased IFN signature and altered level of TLR8 expression in SSc monocytes carrying infectious EBV compared to HD monocytes. This study provides the first evidence of infectious EBV in monocytes from patients with SSc and links EBV to the activation of TLR8 and IFN innate immune response in freshly isolated SSc monocytes. This study provides the first evidence of EBV replication activating the TLR8 molecular pathway in primary monocytes. Immunogenicity of infectious EBV suggests a novel mechanism mediating monocyte inflammation in SSc, by which EBV triggers the innate immune response in infected cells.

Interleukin 35 Expression Correlates With Microvessel Density in Pancreatic Ductal Adenocarcinoma, Recruits Monocytes, and Promotes Growth and Angiogenesis of Xenograft Tumors in Mice.

PubMed

Huang, Chongbiao; Li, Zengxun; Li, Na; Li, Yang; Chang, Antao; Zhao, Tiansuo; Wang, Xiuchao; Wang, Hongwei; Gao, Song; Yang, Shengyu; Hao, Jihui; Ren, He

2018-02-01

Cells of the monocyte lineage contribute to tumor angiogenesis. Interleukin 35 (IL35) is a member of the IL12 family produced by regulatory, but not effector, T cells. IL35 is a dimer comprising the IL12 alpha and IL27 beta chains, encoded by IL12A and EBI3, respectively. Expression of IL35 is increased in pancreatic ductal adenocarcinomas (PDACs) compared with normal pancreatic tissues, and promotes metastasis. We investigated the role of IL35 in monocyte-induced angiogenesis of PDAC in mice. We measured levels of IL35 protein, microvessel density, and numbers of monocytes in 123 sequential PDAC tissues from patients who underwent surgery in China in 2010. We performed studies with the human PDAC cell lines CFPAC-1, BxPC-3, Panc-1, MIA-PaCa-2, and mouse PDAC cell line Pan02. Monocyte subsets were isolated by flow cytometry from human peripheral blood mononuclear cells. Fused human or mouse IL12A and EBI3 genes were overexpressed in PDAC cells or knocked down using small hairpin RNAs. Cells were grown as xenograft tumors in SCID mice; some mice were given injections of an IL35-neutralizing antibody and tumor growth was monitored. We performed chemotaxis assays to measure the ability of IL35 to recruit monocytes. We analyzed mRNA sequences of 179 PDACs in the Cancer Genome Atlas to identify correlations between expression of IL12A and EBI3 and monocyte markers. Monocytes incubated with IL35 or PDAC cell supernatants were analyzed in tube formation and endothelial migration assays. In PDAC samples from patients, levels of IL35 mRNA and protein correlated with microvessel density and infiltration of monocyte lineage cells. In cells and mice with xenograft tumors, IL35 increased recruitment of monocytes into PDAC tumors, which required CCL5. Upon exposure to IL35, monocytes increased expression of genes whose products promote angiogenesis (CXCL1 and CXCL8). IL35 activated transcription of CCL5, CXCL1, and CXCL8 by inducing GP130 signaling, via IL12RB2 and phosphorylation of STAT1 and STAT4. A combination of a neutralizing antibody against IL35 and gemcitabine significantly decreased monocyte infiltration, microvessel density, and volume of xenograft tumors grown from PDAC cells in mice. PDAC cells produce IL35 to recruit monocytes via CCL5 and induce macrophage to promote angiogenesis via expression of CXCL1 and CXCL8. IL35 signaling promotes angiogenesis and growth of xenograft tumors from PDAC cells in mice. IL35 might serve as a therapeutic target for patients with pancreatic cancer. Copyright © 2018. Published by Elsevier Inc.

Epigallocatechin 3-gallate inhibits 7-ketocholesterol-induced monocyte-endothelial cell adhesion.

PubMed

Yamagata, Kazuo; Tanaka, Noriko; Suzuki, Koichi

2013-07-01

7-Ketocholesterol (7KC) induces monocytic adhesion to endothelial cells, and induces arteriosclerosis while high-density lipoprotein (HDL) inhibits monocytic adhesion to the endothelium. Epigallocatechin 3-gallate (EGCG) was found to have a protective effect against arteriosclerosis. Therefore, the purpose of this study was to examine the possible HDL-like mechanisms of EGCG in endothelial cells by investigating whether EGCG inhibits 7KC-induced monocyte-endothelial cell adhesion by activating HDL-dependent signal transduction pathways. 7KC and/or EGCG were added to human endothelial cells (ISO-HAS), and the adhesion of pro-monocytic U937 cells was examined. The expression of genes associated with HDL effects such as Ca(2+)/calmodulin-dependent kinase II (CaMKKII), liver kinase B (LKD1), PSD-95/Dlg/ZO-1 kinase 1 (PDZK1), phosphatidylinositol 3-kinase (PI3K), intercellular adhesion molecule-1 (ICAM-1), monocyte chemotactic protein-1 (MCP-1), and endothelial nitric oxide synthase (eNOS) was examined by RT-PCR, and ICAM-1 protein expression was evaluated by western blot (WB). Production of reactive oxygen species (ROS) was examined with H2DCFDA. 7KC significantly induced adhesion of U937 cells to human endothelial cells while significantly increasing gene expressions of ICAM-1 and MCP-1 and decreasing eNOS and CaMKKII gene expressions. EGCG inhibited 7KC-induced monocytic adhesion to endothelial cells, and induced expression of eNOS and several genes involved in the CaMKKII pathway. Stimulation of endothelial cells with EGCG produced intracellular ROS, whereas treatment with N-acetylcysteine (NAC) blocked EGCG-induced expression of eNOS and CaMKKII. These results suggest that inhibition of monocyte-endothelial cell adhesion by EGCG is associated with CaMKKII pathway activation by ROS. Inhibition of 7KC-induced monocyte-endothelial cell adhesion induced by EGCG may function similarly to HDL. Copyright © 2013 Elsevier Inc. All rights reserved.

DNA activates human immune cells through a CpG sequence-dependent manner

PubMed Central

Bauer, M; Heeg, K; Wagner, H; Lipford, G B

1999-01-01

While bacterial DNA and cytosine–guanosine-dinucleotide-containing oligonucleotides (CpG ODN) are well described activators of murine immune cells, their effect on human cells is inconclusive. We investigated their properties on human peripheral blood mononuclear cells (PBMC) and subsets thereof, such as purified monocytes, T and B cells. Here we demonstrate that bacterial DNA and CpG ODN induce proliferation of B cells, while other subpopulations, such as monocytes and T cells, did not proliferate. PBMC mixed cell cultures, as well as purified monocytes, produced interleukin-6 (IL-6), IL-12 and tumour necrosis factor-α upon stimulation with bacterial DNA; however, only IL-6 and IL-12 secretion became induced upon CpG ODN stimulation. We conclude that monocytes, but not B or T cells, represent the prime source of cytokines. Monocytes up-regulated expression of antigen-presenting, major histocompatibility complex class I and class II molecules in response to CpG DNA. In addition, both monocytes and B cells up-regulate costimulatory CD86 and CD40 molecules. The activation by CpG ODN depended on sequence motifs containing the core dinucleotide CG since destruction of the motif strongly reduced immunostimulatory potential. PMID:10457226

Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype.

PubMed

Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor

2017-03-01

Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4 + T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. Copyright © 2017 Elsevier Inc. All rights reserved.

Interaction studies reveal specific recognition of an anti-inflammatory polyphosphorhydrazone dendrimer by human monocytes.

PubMed

Ledall, Jérémy; Fruchon, Séverine; Garzoni, Matteo; Pavan, Giovanni M; Caminade, Anne-Marie; Turrin, Cédric-Olivier; Blanzat, Muriel; Poupot, Rémy

2015-11-14

Dendrimers are nano-materials with perfectly defined structure and size, and multivalency properties that confer substantial advantages for biomedical applications. Previous work has shown that phosphorus-based polyphosphorhydrazone (PPH) dendrimers capped with azabisphosphonate (ABP) end groups have immuno-modulatory and anti-inflammatory properties leading to efficient therapeutic control of inflammatory diseases in animal models. These properties are mainly prompted through activation of monocytes. Here, we disclose new insights into the molecular mechanisms underlying the anti-inflammatory activation of human monocytes by ABP-capped PPH dendrimers. Following an interdisciplinary approach, we have characterized the physicochemical and biological behavior of the lead ABP dendrimer with model and cell membranes, and compared this experimental set of data to predictive computational modelling studies. The behavior of the ABP dendrimer was compared to the one of an isosteric analog dendrimer capped with twelve azabiscarboxylate (ABC) end groups instead of twelve ABP end groups. The ABC dendrimer displayed no biological activity on human monocytes, therefore it was considered as a negative control. In detail, we show that the ABP dendrimer can bind both non-specifically and specifically to the membrane of human monocytes. The specific binding leads to the internalization of the ABP dendrimer by human monocytes. On the contrary, the ABC dendrimer only interacts non-specifically with human monocytes and is not internalized. These data indicate that the bioactive ABP dendrimer is recognized by specific receptor(s) at the surface of human monocytes.

Differential IL-1β secretion by monocyte subsets is regulated by Hsp27 through modulating mRNA stability.

PubMed

Hadadi, Eva; Zhang, Biyan; Baidžajevas, Kajus; Yusof, Nurhashikin; Puan, Kia Joo; Ong, Siew Min; Yeap, Wei Hseun; Rotzschke, Olaf; Kiss-Toth, Endre; Wilson, Heather; Wong, Siew Cheng

2016-12-15

Monocytes play a central role in regulating inflammation in response to infection or injury, and during auto-inflammatory diseases. Human blood contains classical, intermediate and non-classical monocyte subsets that each express characteristic patterns of cell surface CD16 and CD14; each subset also has specific functional properties, but the mechanisms underlying many of their distinctive features are undefined. Of particular interest is how monocyte subsets regulate secretion of the apical pro-inflammatory cytokine IL-1β, which is central to the initiation of immune responses but is also implicated in the pathology of various auto-immune/auto-inflammatory conditions. Here we show that primary human non-classical monocytes, exposed to LPS or LPS + BzATP (3'-O-(4-benzoyl)benzyl-ATP, a P2X7R agonist), produce approx. 80% less IL-1β than intermediate or classical monocytes. Despite their low CD14 expression, LPS-sensing, caspase-1 activation and P2X7R activity were comparable in non-classical monocytes to other subsets: their diminished ability to produce IL-1β instead arose from 50% increased IL-1β mRNA decay rates, mediated by Hsp27. These findings identify the Hsp27 pathway as a novel therapeutic target for the management of conditions featuring dysregulated IL-1β production, and represent an advancement in understanding of both physiological inflammatory responses and the pathogenesis of inflammatory diseases involving monocyte-derived IL-1β.

Mesenchymal stem cells inhibit dendritic cell differentiation and function by preventing entry into the cell cycle.

PubMed

Ramasamy, Rajesh; Fazekasova, Henrietta; Lam, Eric W-F; Soeiro, Inês; Lombardi, Giovanna; Dazzi, Francesco

2007-01-15

Mesenchymal stem cells (MSCs) play a crucial role in hematopoietic development and have been shown to exert a powerful immunosuppressive effect. In this study, we investigated the effect of bone marrow MSC on the differentiation and function of peripheral blood monocytes into dendritic cells (DCs). Human MSCs, generated from normal bone marrow, were added to peripheral blood monocytes stimulated in vitro with granulocyte-macrophage colony stimulating factor and interleukin-4 to become DCs. Monocytes were then examined for the expression of markers characteristic of DCs and their ability to stimulate allogeneic T cells. In addition, the effect of MSCs on the cell cycle of monocyte-derived DCs and the expression of various cell cycle proteins were analyzed by cytometric analysis and Western blotting with specific antibodies. MSCs blocked the differentiation of monocytes into DCs and impaired their antigen-presenting ability. This resulted from a block of monocytes from entering the G1 phase of the cell cycle with a progressive number of cells accumulating in the G0 phase. Cyclin D2 was downregulated. However, differently from what was observed in T-cells stimulated in the presence of MSCs, the expression of p27 was found decreased, suggesting the involvement of similar but not identical pathways. We conclude that MSCs impair monocyte differentiation and function by interfering with the cell cycle. These findings imply that MSC-induced immunosuppression might be a side product of a more general antiproliferative effect.

Microparticles Engineered to Highly Express Peroxisome Proliferator-Activated Receptor-γ Decreased Inflammatory Mediator Production and Increased Adhesion of Recipient Monocytes

PubMed Central

Sahler, Julie; Woeller, Collynn F.; Phipps, Richard P.

2014-01-01

Circulating blood microparticles are submicron vesicles released primarily by megakaryocytes and platelets that act as transcellular communicators. Inflammatory conditions exhibit elevated blood microparticle numbers compared to healthy conditions. Direct functional consequences of microparticle composition, especially internal composition, on recipient cells are poorly understood. Our objective was to evaluate if microparticle composition could impact the function of recipient cells, particularly during inflammatory provocation. We therefore engineered the composition of megakaryocyte culture-derived microparticles to generate distinct microparticle populations that were given to human monocytes to assay for influences recipient cell function. Herein, we tested the responses of monocytes exposed to either control microparticles or microparticles that contain the anti-inflammatory transcription factor, peroxisome proliferator-activated receptor-γ (PPARγ). In order to normalize relative microparticle abundance from two microparticle populations, we implemented a novel approach that utilizes a Nanodrop Spectrophotometer to assay for microparticle density rather than concentration. We found that when given to peripheral blood mononuclear cells, microparticles were preferentially internalized by CD11b+ cells, and furthermore, microparticle composition had a profound functional impact on recipient monocytes. Specifically, microparticles containing PPARγ reduced activated monocyte production of the proinflammatory cytokines interleukin-8 and monocyte chemotactic protein-1 compared to activated monocytes exposed to control microparticles. Additionally, treatment with PPARγ microparticles greatly increased monocyte cell adherence. This change in morphology occurred simultaneously with increased production of the key extracellular matrix protein, fibronectin and increased expression of the fibronectin-binding integrin, ITGA5. PPARγ microparticles also changed monocyte mRNA levels of several genes including those under PPARγ control. Overall, the delivery of PPARγ from microparticles to human monocytes influenced gene expression, decreased inflammatory mediator production and increased monocyte adherence. These results support the concept that the composition of blood microparticles has a profound impact on the function of cells with which they interact, and likely plays a role in vascular inflammation. PMID:25426628

Microparticles engineered to highly express peroxisome proliferator-activated receptor-γ decreased inflammatory mediator production and increased adhesion of recipient monocytes.

PubMed

Sahler, Julie; Woeller, Collynn F; Phipps, Richard P

2014-01-01

Circulating blood microparticles are submicron vesicles released primarily by megakaryocytes and platelets that act as transcellular communicators. Inflammatory conditions exhibit elevated blood microparticle numbers compared to healthy conditions. Direct functional consequences of microparticle composition, especially internal composition, on recipient cells are poorly understood. Our objective was to evaluate if microparticle composition could impact the function of recipient cells, particularly during inflammatory provocation. We therefore engineered the composition of megakaryocyte culture-derived microparticles to generate distinct microparticle populations that were given to human monocytes to assay for influences recipient cell function. Herein, we tested the responses of monocytes exposed to either control microparticles or microparticles that contain the anti-inflammatory transcription factor, peroxisome proliferator-activated receptor-γ (PPARγ). In order to normalize relative microparticle abundance from two microparticle populations, we implemented a novel approach that utilizes a Nanodrop Spectrophotometer to assay for microparticle density rather than concentration. We found that when given to peripheral blood mononuclear cells, microparticles were preferentially internalized by CD11b+ cells, and furthermore, microparticle composition had a profound functional impact on recipient monocytes. Specifically, microparticles containing PPARγ reduced activated monocyte production of the proinflammatory cytokines interleukin-8 and monocyte chemotactic protein-1 compared to activated monocytes exposed to control microparticles. Additionally, treatment with PPARγ microparticles greatly increased monocyte cell adherence. This change in morphology occurred simultaneously with increased production of the key extracellular matrix protein, fibronectin and increased expression of the fibronectin-binding integrin, ITGA5. PPARγ microparticles also changed monocyte mRNA levels of several genes including those under PPARγ control. Overall, the delivery of PPARγ from microparticles to human monocytes influenced gene expression, decreased inflammatory mediator production and increased monocyte adherence. These results support the concept that the composition of blood microparticles has a profound impact on the function of cells with which they interact, and likely plays a role in vascular inflammation.

Neutrophil and Monocyte Bactericidal Responses to 10 Weeks of Low-Volume High-Intensity Interval or Moderate-Intensity Continuous Training in Sedentary Adults

PubMed Central

Shepherd, Sam O.; Wilson, Oliver J.; Adlan, Ahmed M.; Wagenmakers, Anton J. M.; Shaw, Christopher S.; Lord, Janet M.

2017-01-01

Neutrophils and monocytes are key components of the innate immune system that undergo age-associated declines in function. This study compared the impact of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on immune function in sedentary adults. Twenty-seven (43 ± 11 years) healthy sedentary adults were randomized into ten weeks of either a HIIT (>90% maximum heart rate) or MICT (70% maximum heart rate) group training program. Aerobic capacity (VO2peak), neutrophil and monocyte bacterial phagocytosis and oxidative burst, cell surface receptor expression, and systemic inflammation were measured before and after the training. Total exercise time commitment was 57% less for HIIT compared to that for MICT while both significantly improved VO2peak similarly. Neutrophil phagocytosis and oxidative burst and monocyte phagocytosis and percentage of monocytes producing an oxidative burst were improved by training similarly in both groups. Expression of monocyte but not neutrophil CD16, TLR2, and TLR4 was reduced by training similarly in both groups. No differences in systemic inflammation were observed for training; however, leptin was reduced in the MICT group only. With similar immune-enhancing effects for HIIT compared to those for MICT at 50% of the time commitment, our results support HIIT as a time efficient exercise option to improve neutrophil and monocyte function. PMID:28656073

Comparative analysis of signature genes in PRRSV-infected porcine monocyte-derived dendritic cells at differential activation statuses

USDA-ARS?s Scientific Manuscript database

Activation statuses of monocytic cells including monocytes, macrophages and dendritic cells (DCs) are critically important for antiviral immunity. In particular, some devastating viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), are capable of directly infecting these c...

Inflammatory biomarkers for persistent fatigue in breast cancer survivors.

PubMed

Collado-Hidalgo, Alicia; Bower, Julienne E; Ganz, Patricia A; Cole, Steve W; Irwin, Michael R

2006-05-01

This study seeks to define immunologic and inflammatory variables associated with persistent post-treatment fatigue in breast cancer survivors. Leukocyte subsets, plasma inflammatory markers, and ex vivo proinflammatory cytokine production were assessed in 50 fatigued and nonfatigued breast cancer survivors recruited > or = 2 years after successful primary therapy. Multivariate statistical analyses were used to define a composite immunologic biomarker of fatigue risk. Fatigued breast cancer survivors were distinguished from nonfatigued survivors by increased ex vivo monocyte production of interleukin (IL)-6 and tumor necrosis factor-alpha following lipopolysaccharide stimulation, elevated plasma IL-1ra and soluble IL-6 receptor (sIL-6R/CD126), decreased monocyte cell-surface IL-6R, and decreased frequencies of activated T lymphocytes and myeloid dendritic cells in peripheral blood (all P < 0.05). An inverse correlation between sIL-6R and cell-surface IL-6R was consistent with inflammation-mediated shedding of IL-6R, and in vitro studies confirmed that proinflammatory cytokines induced such shedding. Multivariate linear discriminant function analysis identified two immunologic markers, the ratio of sIL-6R to monocyte-associated IL-6R and decreased circulating CD69+ T lymphocytes, as highly diagnostic of fatigue (P = 0.0005), with cross-validation estimates indicating 87% classification accuracy (sensitivity = 0.83; specificity = 0.83). These results extend links between fatigue and inflammatory markers to show a functional alteration in proinflammatory cytokine response to lipopolysaccharide and define a prognostic biomarker of behavioral fatigue.

Differential pattern of cell-surface and soluble TREM-1 between sepsis and SIRS.

PubMed

Oku, Reiko; Oda, Shigeto; Nakada, Taka-aki; Sadahiro, Tomohito; Nakamura, Masataka; Hirayama, Yoh; Abe, Ryuzo; Tateishi, Yoshihisa; Ito, Michihiro; Iseki, Toru; Hirasawa, Hiroyuki

2013-01-01

Triggering receptor expressed on myeloid cells-1 (TREM-1) was reported to play a key roll in amplification of production of inflammatory cytokines. TREM-1 is suggested to be a specific biomarker for sepsis for this reason, but the clinical significance of TREM-1 has not been elucidated. We investigated TREM-1 expression on the cell-surface, and plasma levels of soluble TREM-1 (sTREM-1) in patients with non-infectious systemic inflammatory response syndrome (SIRS) and sepsis admitted to the ICU. Thirty-five patients with SIRS and 21 patients with sepsis admitted to ICU were subjected to the study. TREM-1 expressions on the surfaces of monocytes and neutrophils were measured by flow cytometry. Plasma sTREM-1 level and serum interleukin (IL)-6 level were measured. Septic patients had decreased TREM-1 expression, clearly on neutrophils or to a lesser extent on monocyte compared to SIRS patients on ICU admission (neutrophils p<0.001, monocyte p<0.05). TREM-1 expression on neutrophils had a significant inverse correlation with serum IL-6 level (r=-0.64, p<0.0001). Plasma sTREM-1 level in septic patients was significantly higher than that in SIRS patients (p<0.05). Plasma sTREM-1 level positively correlated with severity score and non-survivors had increased plasma sTREM-1 level compared to survivors in all SIRS/sepsis patients (p<0.05). Patients with sepsis had increased soluble TREM-1 and decreased TREM-1 expression on neutrophil compared to SIRS patients. sTREM-1 may be useful to evaluate disease severity and outcome of patients with SIRS or sepsis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Calcium influx through the TRPV1 channel of endothelial cells (ECs) correlates with a stronger adhesion between monocytes and ECs.

PubMed

Himi, N; Hamaguchi, A; Hashimoto, K; Koga, T; Narita, K; Miyamoto, O

2012-01-01

Atherosclerosis is thought to be initiated by the transendothelial migration of monocytes. In the early stage of this process, the adhesion of monocytes to endothelial cells is supported by an increase in the intracellular concentration of calcium ion ([Ca(2+)]i) in endothelial cells. However, the main source of Ca(2+) has been unclear. In this study, the changes in ionic transmittance and [Ca(2+)]i due to the adhesion of monocytes were continuously measured by an electrophysiological technique and fluorescent imaging. Especially, we focused on transient receptor potential vanilloid channel 1 (TRPV1) as a Ca(2+) channel that could influence the adhesion of monocytes. Whole-cell current was continuously recorded in human umbilical vein endothelial cells (HUVECs) by a patch electrode. The adhesion of monocytes (THP-1) induced a transient inward current in HUVECs, as well as an elevation of [Ca(2+)]i. This inward element was abolished by the application of 100 nM SB366,791, a selective antagonist of TRPV1 channel. Furthermore, SB366,791 significantly decreased the number of THP-1 cells that adhered to HUVECs (control: 231 ± 38, SB366,791: 96 ± 16 cells/mm2). These results suggest that an inward calcium current via the TRPV1 channels of endothelial cells correlates with a stronger adhesion between monocytes and endothelial cells.

Mouse CD23 regulates monocyte activation through an interaction with the adhesion molecule CD11b/CD18.

PubMed

Lecoanet-Henchoz, S; Plater-Zyberk, C; Graber, P; Gretener, D; Aubry, J P; Conrad, D H; Bonnefoy, J Y

1997-09-01

CD23 is expressed on a variety of hemopoietic cells. Recently, we have reported that blocking CD23 interactions in a murine model of arthritis resulted in a marked improvement of disease severity. Here, we demonstrate that CD11b, the alpha chain of the beta 2 integrin adhesion molecule complex CD11b/CD18 expressed on monocytes interacts with CD23. Using a recombinant fusion protein (ZZ-CD23), murine CD23 was shown to bind to peritoneal macrophages and peripheral blood cells isolated from mice as well as the murine macrophage cell line, RAW. The interactions between mouse ZZ-CD23 and CD11b/CD18-expressing cells were significantly inhibited by anti-CD11b monoclonal antibodies. A functional consequence was then demonstrated by inducing an up-regulation of interleukin-6 (IL-6) production following ZZ-CD23 incubation with monocytes. The addition of Fab fragments generated from the monoclonal antibody CD11b impaired this cytokine production by 50%. Interestingly, a positive autocrine loop was identified as IL-6 was shown to increase CD23 binding to macrophages. These results demonstrate that similar to findings using human cells, murine CD23 binds to the surface adhesion molecule, CD11b, and these interactions regulate biological activities of murine myeloid cells.

Characterization of MHC-II antigen presentation by B cells and monocytes from older individuals

PubMed Central

HL, Clark; R, Banks; L, Jones; TR, Hornick; PA, Higgins; CJ, Burant; DH, Canaday

2012-01-01

In this study we examine the effects of aging on antigen presentation of B cells and monocytes. We compared the antigen presentation function of peripheral blood B cells from young and old subjects using a system that specifically measures the B cell receptor (BCR)-mediated MHC-II antigen presentation. Monocytes were studied as well. Overall the mean magnitude of antigen presentation of soluble antigen and peptide was not different in older and younger subjects for both B cells and monocytes. Older subjects, however, showed increased heterogeneity of BCR-mediated antigen presentation by their B cells. The magnitude and variability of peptide presentation, which does not require uptake and processing, was the same between groups. Presentation by monocytes had similar variability between the older and younger subjects. These data suggest that poor B cell antigen processing, which results in diminished presentation in some older individuals may contribute to poor vaccine responses. PMID:22797466

Synergistic effect of muramyldipeptide with lipopolysaccharide or lipoteichoic acid to induce inflammatory cytokines in human monocytic cells in culture.

PubMed

Yang, S; Tamai, R; Akashi, S; Takeuchi, O; Akira, S; Sugawara, S; Takada, H

2001-04-01

An analog of 1alpha,25-dihydroxyvitamin D3, 22-oxyacalcitriol (OCT), differentiated human monocytic THP-1 and U937 cells to express membrane CD14 and rendered the cells responsive to bacterial cell surface components. Both THP-1 and U937 cells expressed Toll-like receptor 4 (TLR4) on the cell surface and TLR4 mRNA in the cells, irrespective of OCT treatment. In contrast, OCT-treated U937 cells scarcely expressed TLR2 mRNA, while OCT-treated THP-1 cells expressed this transcript. Muramyldipeptide (MDP) by itself exhibited only a weak ability to induce secretion of inflammatory cytokines such as interleukin-8 (IL-8) in the OCT-differentiated THP-1 cells but showed marked synergistic effects with Salmonella lipopolysaccharide (LPS) or lipoteichoic acid (LTA) from Staphylococcus aureus, both of which exhibited strong activities. Combinatory stimulation with LPS plus LTA did not show a synergistic effect on OCT-differentiated THP-1 cells. Similar results were observed in OCT-differentiated U937 cells, although combination experiments were carried out only with MDP plus LPS. Anti-CD14 monoclonal antibody (MAb) MY4, anti-TLR4 MAb HTA125, and the synthetic lipid A precursor LA-14-PP almost completely inhibited the IL-8-inducing activities of LTA as well as LPS on OCT-treated THP-1 cells, but these treatments increased MDP activity. OCT-treated THP-1 cells primed with MDP exhibited enhanced production of IL-8 upon stimulation with LPS, while the cells primed with LPS showed no change in production upon stimulation with MDP. MDP up-regulated mRNA expression of an adapter molecule to TLRs, MyD88, to an extent similar to that for LPS in OCT-treated THP-1 cells. These findings suggested that LTA as well as LPS activated human monocytic cells in a CD14- and TLR4-dependent manner, whereas MDP exhibited activity in a CD14-, TLR4-, and probably TLR2-independent manner and exhibited synergistic and priming effects on the cells for cytokine production in response to various bacterial components.

Proangiogenic hematopoietic cells of monocytic origin: roles in vascular regeneration and pathogenic processes of systemic sclerosis.

PubMed

Yamaguchi, Yukie; Kuwana, Masataka

2013-02-01

New blood vessel formation is critical, not only for organ development and tissue regeneration, but also for various pathologic processes, such as tumor development and vasculopathy. The maintenance of the postnatal vascular system requires constant remodeling, which occurs through angiogenesis, vasculogenesis, and arteriogenesis. Vasculogenesis is mediated by the de novo differentiation of mature endothelial cells from endothelial progenitor cells (EPCs). Early studies provided evidence that bone marrow-derived CD14⁺ monocytes can serve as a subset of EPCs because of their expression of endothelial markers and ability to promote neovascularization in vitro and in vivo. However, the current consensus is that monocytic cells do not give rise to endothelial cells in vivo, but function as support cells, by promoting vascular formation and repair through their immediate recruitment to the site of vascular injury, secretion of proangiogenic factors, and differentiation into mural cells. These monocytes that function in a supporting role in vascular repair are now termed monocytic pro-angiogenic hematopoietic cells (PHCs). Systemic sclerosis (SSc) is a multisystem connective tissue disease characterized by excessive fibrosis and microvasculopathy, along with poor vascular formation and repair. We recently showed that in patients with SSc, circulating monocytic PHCs increase dramatically and have enhanced angiogenic potency. These effects may be induced in response to defective vascular repair machinery. Since CD14⁺ monocytes can also differentiate into fibroblast-like cells that produce extracellular matrix proteins, here we propose a new hypothesis that aberrant monocytic PHCs, once mobilized into circulation, may also contribute to the fibrotic process of SSc.

Differential effects of malignant mesothelioma cells on THP-1 monocytes and macrophages.

PubMed

Izzi, Valerio; Chiurchiù, Valerio; D'Aquilio, Fabiola; Palumbo, Camilla; Tresoldi, Ilaria; Modesti, Andrea; Baldini, Patrizia M

2009-02-01

Malignant mesothelioma (MM) is a highly fatal tumor arising from inner body membranes, whose extensive growth is facilitated by its week immunogenicity and by its ability to blunt the immune response which should arise from the huge mass of leukocytes typically infiltrating this tumor. It has been reported that the inflammatory infiltrate found in MM tissues is characterized by a high prevalence of macrophages. Thus, in this work we evaluated the ability of human MM cells to modulate the inflammatory phenotype of human THP-1 monocytes and macrophages, a widely used in vitro model of monocyte/macrophage differentiation. Furthermore, we tested the hypothesis that the exposure to MM cells could alter the differentiation of THP-1 monocytes favoring the development of alternatively activated, tumor-supporting macrophages. Our data prove for the first time that MM cells can polarize monocytes towards an altered inflammatory phenotype and macrophages towards an immunosuppressive phenotype. Moreover, we demonstrate that monocytes cocultivated with MM cells 'keep a memory' of their encounter with the tumor which influences their differentiation to macrophages. On the whole, we provide evidence that MM cells exert distinct, cell-specific effects on monocytes and macrophages. The thorough characterization of such effects may be of a crucial importance for the rational design of new immunotherapeutic protocols.

Monocytes inhibit NK activity via TGF-β in patients with obstructive sleep apnoea.

PubMed

Hernández-Jiménez, Enrique; Cubillos-Zapata, Carolina; Toledano, Victor; Pérez de Diego, Rebeca; Fernández-Navarro, Isabel; Casitas, Raquel; Carpio, Carlos; Casas-Martín, Jose; Valentín, Jaime; Varela-Serrano, Anibal; Avendaño-Ortiz, Jose; Alvarez, Enrique; Aguirre, Luis A; Pérez-Martínez, Antonio; De Miguel, Maria P; Belda-Iniesta, Cristobal; García-Río, Francisco; López-Collazo, Eduardo

2017-06-01

Obstructive sleep apnoea (OSA) is associated with cancer incidence and mortality. The contribution of the immune system appears to be crucial; however, the potential role of monocytes and natural killer (NK) cells remains unclear.Quantitative reverse transcriptase PCR, flow cytometry and in vitro assays were used to analyse the phenotype and immune response activity in 92 patients with OSA (60 recently diagnosed untreated patients and 32 patients after 6 months of treatment with continuous positive airway pressure (CPAP)) and 29 healthy volunteers (HV).We determined that monocytes in patients with OSA exhibit an immunosuppressive phenotype, including surface expression of glycoprotein-A repetitions predominant protein (GARP) and transforming growth factor-β (TGF-β), in contrast to those from the HV and CPAP groups. High levels of TGF-β were detected in OSA sera. TGF-β release by GARP + monocytes impaired NK cytotoxicity and maturation. This altered phenotype correlated with the hypoxic severity clinical score (CT90). Reoxygenation eventually restored the altered phenotypes and cytotoxicity.This study demonstrates that GARP + monocytes from untreated patients with OSA have an NK-suppressing role through their release of TGF-β. Our findings show that monocyte plasticity immunomodulates NK activity in this pathology, suggesting a potential role in cancer incidence. Copyright ©ERS 2017.

Immune complex-induced human monocyte procoagulant activity. I. a rapid unidirectional lymphocyte-instructed pathway.

PubMed

Schwartz, B S; Edgington, T S

1981-09-01

It has previously been described that soluble antigen:antibody complexes in antigen excess can induce an increase in the procoagulant activity of human peripheral blood mononuclear cells. It has been proposed that this response may explain the presence of fibrin in immune complex-mediated tissue lesions. In the present study we define cellular participants and their roles in the procoagulant response to soluble immune complexes. Monocytes were shown by cell fractionation and by a direct cytologic assay to be the cell of origin of the procoagulant activity; and virtually all monocytes were able to participate in the response. Monocytes, however, required the presence of lymphocytes to respond. The procoagulant response required cell cooperation, and this collaborative interaction between lymphocytes and monocytes appeared to be unidirectional. Lymphocytes once triggered by immune complexes induced monocytes to synthesize the procoagulant product. Intact viable lymphocytes were required to present instructions to monocytes; no soluble mediator could be found to subserve this function. Indeed, all that appeared necessary to induce monocytes to produce procoagulant activity was an encounter with lymphocytes that had previously been in contact with soluble immune complexes. The optimum cellular ratio for this interaction was four lymphocytes per monocyte, about half the ratio in peripheral blood. The procoagulant response was rapid, reaching a maximum within 6 h after exposure to antigen:antibody complexes. The procoagulant activity was consistent with tissue factor because Factors VII and X and prothrombin were required for clotting of fibrinogen. WE propose that this pathway differs from a number of others involving cells of the immune system. Elucidation of the pathway may clarify the role of this lymphocyte-instructed monocyte response in the Shwartzman phenomenon and other thrombohemorrhagic events associated with immune cell function and the formation of immune complexes.

Neutrophils and monocytes transport tumor cell antigens from the peritoneal cavity to secondary lymphoid tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terasawa, Masao; Nagata, Kisaburo; Kobayashi, Yoshiro

2008-12-12

Antigen-transporting cells take up pathogens, and then migrate from sites of inflammation to secondary lymphoid tissues to induce an immune response. Among antigen-transporting cells, dendritic cells (DCs) are believed to be the most potent and professional antigen-presenting cells that can stimulate naive T cells. However, the cells that transport antigens, tumor cell antigens in particular, have not been clearly identified. In this study we have analyzed what types of cells transport tumor cell antigens to secondary lymphoid tissues. We show that neutrophils, monocytes and macrophages but not DCs engulf X-irradiated P388 leukemic cells after their injection into the peritoneal cavity,more » and that neutrophils and monocytes but not macrophages migrate to the parathymic lymph nodes (pLN), the blood, and then the spleen. The monocytes in the pLN comprise Gr-1{sup -} and Gr-1{sup +} ones, and some of these cells express CD11c. Overall, this study demonstrates that neutrophils and monocytes transport tumor cell antigens from the peritoneal cavity to secondary lymphoid tissues.« less

Human platelet lysate is a successful alternative serum supplement for propagation of monocyte-derived dendritic cells.

PubMed

Švajger, Urban

2017-04-01

Clinical protocols for dendritic cell (DC) generation from monocytes require the use of animal serum-free supplements. Serum-free media can also require up to 1% of serum supplementation. In addition, recommendations based on the 3Rs (Refinement, Reduction, Replacement) principle also recommend the use of non-animal sera in in vitro studies. The aim of this study was to explore the potential use of platelet lysate (PL) for generation of optimally differentiated DCs from monocytes. Cells were isolated from buffy coats from healthy volunteers using immunomagnetic selection. DCs were differentiated in RPMI1640 supplemented with either 10% fetal bovine serum (FBS), 10% AB serum or 10% PL with the addition of granulocyte monocyte colony stimulating factor and interleukin-4. Generated DCs were assessed for their morphology, viability, endocytotic capacity, surface phenotype (immature, mature and tolerogenic DCs) and activation of important signaling pathways. DC function was evaluated on the basis of their allostimulatory capacity, cytokine profile and ability to induce different T-helper subsets. DCs generated with PL displayed normal viability, morphology and endocytotic capacity. Their differentiation and maturation phenotype was comparable to FBS-cultured DCs. They showed functional plasticity and up-regulated tolerogenic markers in response to their environment. PL-cultured mature DCs displayed unhindered allostimulatory potential and the capacity to induce Th1 responses. The use of PL allowed for activation of crucial signaling proteins associated with DC differentiation and maturation. This study demonstrates for the first time that human PL represents a successful alternative to FBS in differentiation of DCs from monocytes. DCs display the major phenotypic and functional characteristics compared with existing culture protocols. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Inflammatory Monocytes Recruited to the Liver within 24 Hours after Virus-Induced Inflammation Resemble Kupffer Cells but Are Functionally Distinct

PubMed Central

Movita, Dowty; Biesta, Paula; Kreefft, Kim; Haagmans, Bart; Zuniga, Elina; Herschke, Florence; De Jonghe, Sandra; Janssen, Harry L. A.; Gama, Lucio; Boonstra, Andre

2015-01-01

ABSTRACT Due to a scarcity of immunocompetent animal models for viral hepatitis, little is known about the early innate immune responses in the liver. In various hepatotoxic models, both pro- and anti-inflammatory activities of recruited monocytes have been described. In this study, we compared the effect of liver inflammation induced by the Toll-like receptor 4 ligand lipopolysaccharide (LPS) with that of a persistent virus, lymphocytic choriomeningitis virus (LCMV) clone 13, on early innate intrahepatic immune responses in mice. LCMV infection induces a remarkable influx of inflammatory monocytes in the liver within 24 h, accompanied by increased transcript levels of several proinflammatory cytokines and chemokines in whole liver. Importantly, while a single LPS injection results in similar recruitment of inflammatory monocytes to the liver, the functional properties of the infiltrating cells are dramatically different in response to LPS versus LCMV infection. In fact, intrahepatic inflammatory monocytes are skewed toward a secretory phenotype with impaired phagocytosis in LCMV-induced liver inflammation but exhibit increased endocytic capacity after LPS challenge. In contrast, F4/80high-Kupffer cells retain their steady-state endocytic functions upon LCMV infection. Strikingly, the gene expression levels of inflammatory monocytes dramatically change upon LCMV exposure and resemble those of Kupffer cells. Since inflammatory monocytes outnumber Kupffer cells 24 h after LCMV infection, it is highly likely that inflammatory monocytes contribute to the intrahepatic inflammatory response during the early phase of infection. Our findings are instrumental in understanding the early immunological events during virus-induced liver disease and point toward inflammatory monocytes as potential target cells for future treatment options in viral hepatitis. IMPORTANCE Insights into how the immune system deals with hepatitis B virus (HBV) and HCV are scarce due to the lack of adequate animal model systems. This knowledge is, however, crucial to developing new antiviral strategies aimed at eradicating these chronic infections. We model virus-host interactions during the initial phase of liver inflammation 24 h after inoculating mice with LCMV. We show that infected Kupffer cells are rapidly outnumbered by infiltrating inflammatory monocytes, which secrete proinflammatory cytokines but are less phagocytic. Nevertheless, these recruited inflammatory monocytes start to resemble Kupffer cells on a transcript level. The specificity of these cellular changes for virus-induced liver inflammation is corroborated by demonstrating opposite functions of monocytes after LPS challenge. Overall, this demonstrates the enormous functional and genetic plasticity of infiltrating monocytes and identifies them as an important target cell for future treatment regimens. PMID:25673700

BCAP inhibits proliferation and differentiation of myeloid progenitors in the steady state and during demand situations.

PubMed

Duggan, Jeffrey M; Buechler, Matthew B; Olson, Rebecca M; Hohl, Tobias M; Hamerman, Jessica A

2017-03-16

B-cell adaptor for phosphatidylinositol 3-kinase (BCAP) is a signaling adaptor expressed in mature hematopoietic cells, including monocytes and neutrophils. Here we investigated the role of BCAP in the homeostasis and development of these myeloid lineages. BCAP -/- mice had more bone marrow (BM) monocytes than wild-type (WT) mice, and in mixed WT:BCAP -/- BM chimeras, monocytes and neutrophils skewed toward BCAP -/- origin, showing a competitive advantage for BCAP -/- myeloid cells. BCAP was expressed in BM hematopoietic progenitors, including lineage - Sca-1 + c-kit + (LSK), common myeloid progenitor, and granulocyte/macrophage progenitor (GMP) cells. At the steady state, BCAP -/- GMP cells expressed more IRF8 and less C/EBPα than did WT GMP cells, which correlated with an increase in monocyte progenitors and a decrease in granulocyte progenitors among GMP cells. Strikingly, BCAP -/- progenitors proliferated and produced more myeloid cells of both neutrophil and monocyte/macrophage lineages than did WT progenitors in myeloid colony-forming unit assays, supporting a cell-intrinsic role of BCAP in inhibiting myeloid proliferation and differentiation. Consistent with these findings, during cyclophosphamide-induced myeloablation or specific monocyte depletion, BCAP -/- mice replenished circulating monocytes and neutrophils earlier than WT mice. During myeloid replenishment after cyclophosphamide-induced myeloablation, BCAP -/- mice had increased LSK proliferation and increased numbers of LSK and GMP cells compared with WT mice. Furthermore, BCAP -/- mice accumulated more monocytes and neutrophils in the spleen than did WT mice during Listeria monocytogenes infection. Together, these data identify BCAP as a novel inhibitor of myelopoiesis in the steady state and of emergency myelopoiesis during demand conditions. © 2017 by The American Society of Hematology.

Bone marrow-resident NK cells prime monocytes for regulatory function during infection

PubMed Central

Askenase, Michael H.; Han, Seong-Ji; Byrd, Allyson L.; da Fonseca, Denise Morais; Bouladoux, Nicolas; Wilhelm, Christoph; Konkel, Joanne E.; Hand, Timothy W.; Lacerda-Queiroz, Norinne; Su, Xin-Zhuan; Trinchieri, Giorgio; Grainger, John R.; Belkaid, Yasmine

2015-01-01

SUMMARY Tissue-infiltrating Ly6Chi monocytes play diverse roles in immunity, ranging from pathogen killing to immune regulation. How and where this diversity of function is imposed remains poorly understood. Here we show that during acute gastrointestinal infection, priming of monocytes for regulatory function preceded systemic inflammation and was initiated prior to bone marrow egress. Notably, natural killer (NK) cell-derived IFN-γ promoted a regulatory program in monocyte progenitors during development. Early bone marrow NK cell activation was controlled by systemic interleukin-12 (IL-12) produced by Batf3-dependent dendritic cells (DC) in the mucosal-associated lymphoid tissue (MALT). This work challenges the paradigm that monocyte function is dominantly imposed by local signals following tissue recruitment, and instead proposes a sequential model of differentiation in which monocytes are pre-emptively educated during development in the bone marrow to promote their tissue-specific function. PMID:26070484

Outer Membrane Vesicles Prime and Activate Macrophage Inflammasomes and Cytokine Secretion In Vitro and In Vivo

PubMed Central

Cecil, Jessica D.; O’Brien-Simpson, Neil M.; Lenzo, Jason C.; Holden, James A.; Singleton, William; Perez-Gonzalez, Alexis; Mansell, Ashley; Reynolds, Eric C.

2017-01-01

Outer membrane vesicles (OMVs) are proteoliposomes blebbed from the surface of Gram-negative bacteria. Chronic periodontitis is associated with an increase in subgingival plaque of Gram-negative bacteria, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. In this study, we investigated the immune-modulatory effects of P. gingivalis, T. denticola, and T. forsythia OMVs on monocytes and differentiated macrophages. All of the bacterial OMVs were phagocytosed by monocytes, M(naïve) and M(IFNγ) macrophages in a dose-dependent manner. They also induced NF-κB activation and increased TNFα, IL-8, and IL-1β cytokine secretion. P. gingivalis OMVs were also found to induce anti-inflammatory IL-10 secretion. Although unprimed monocytes and macrophages were resistant to OMV-induced cell death, lipopolysaccharide or OMV priming resulted in a significantly reduced cell viability. P. gingivalis, T. denticola, and T. forsythia OMVs all activated inflammasome complexes, as monitored by IL-1β secretion and ASC speck formation. ASC was critical for OMV-induced inflammasome formation, while AIM2−/− and Caspase-1−/− cells had significantly reduced inflammasome formation and NLRP3−/− cells exhibited a slight reduction. OMVs were also found to provide both priming and activation of the inflammasome complex. High-resolution microscopy and flow cytometry showed that P. gingivalis OMVs primed and activated macrophage inflammasomes in vivo with 80% of macrophages exhibiting inflammasome complex formation. In conclusion, periodontal pathogen OMVs were found to have significant immunomodulatory effects upon monocytes and macrophages and should therefore influence pro-inflammatory host responses associated with disease. PMID:28890719

Bone marrow chimeric mice reveal a role for CX₃CR1 in maintenance of the monocyte-derived cell population in the olfactory neuroepithelium.

PubMed

Vukovic, Jana; Blomster, Linda V; Chinnery, Holly R; Weninger, Wolfgang; Jung, Steffen; McMenamin, Paul G; Ruitenberg, Marc J

2010-10-01

Macrophages in the olfactory neuroepithelium are thought to play major roles in tissue homeostasis and repair. However, little information is available at present about possible heterogeneity of these monocyte-derived cells, their turnover rates, and the role of chemokine receptors in this process. To start addressing these issues, this study used Cx₃cr1(gfp) mice, in which the gene sequence for eGFP was knocked into the CX₃CR1 gene locus in the mutant allele. Using neuroepithelial whole-mounts from Cx₃cr1(gfp/+) mice, we show that eGFP(+) cells of monocytic origin are distributed in a loose network throughout this tissue and can be subdivided further into two immunophenotypically distinct subsets based on MHC-II glycoprotein expression. BM chimeric mice were created using Cx₃cr1(gfp/+) donors to investigate turnover of macrophages (and other monocyte-derived cells) in the olfactory neuroepithelium. Our data indicate that the monocyte-derived cell population in the olfactory neuroepithelium is actively replenished by circulating monocytes and under the experimental conditions, completely turned over within 6 months. Transplantation of Cx₃cr1(gfp/gfp) (i.e., CX₃CR1-deficient) BM partially impaired the replenishment process and resulted in an overall decline of the total monocyte-derived cell number in the olfactory epithelium. Interestingly, replenishment of the CD68(low)MHC-II(+) subset appeared minimally affected by CX₃CR1 deficiency. Taken together, the established baseline data about heterogeneity of monocyte-derived cells, their replenishment rates, and the role of CX₃CR1 provide a solid basis to further examine the importance of different monocyte subsets for neuroregeneration at this unique frontier with the external environment.

The role of complement C3 and fibrinogen in monocyte adhesion to PEO like plasma deposited tetraglyme

PubMed Central

Szott, Luisa M.; Horbett, Thomas A.

2010-01-01

The role of complement C3 in mediating adhesion of monocytes to plasma deposited tetraglyme surfaces was studied. Although fibrinogen (Fg) is usually considered the main factor in mediating phagocyte attachment, plasma deposited PEO-like tetraethylene glycol dimethyl ether (tetraglyme) coatings that have ultra-low Fg adsorption (< 10 ng/cm2) from low concentration solutions and low monocyte adhesion in vitro still show high phagocyte adhesion after short implantations and later become encapsulated when tested in vivo. To test whether higher Fg adsorption under in vivo conditions could explain the higher in vivo reactivity, we again measured the resistance of tetraglyme films to Fg adsorption. We found a surprising and previously unreported increased amount of adsorbed Fg on tetraglyme surfaces from higher concentration protein solutions. However, monocyte adhesion to tetraglyme did not markedly increase despite the increased Fg adsorption. We thus suspected proteins other than Fg must be responsible for the increased in vivo reactivity. We found that on tetraglyme pre-adsorbed with C3-depleted serum, monocyte adhesion was greatly reduced as compared to samples adsorbed with normal serum. Addition of exogenous pure C3 to the serum used to pre-adsorb the surfaces restored monocyte adhesion to tetraglyme coatings. While Fg clearly plays an important role in mediating monocyte adhesion to tetraglyme surfaces, the results show an additional role for adsorbed C3 in monocyte adhesion. PMID:20939050

Induction of ceruloplasmin synthesis by IFN-gamma in human monocytic cells

NASA Technical Reports Server (NTRS)

Mazumder, B.; Mukhopadhyay, C. K.; Prok, A.; Cathcart, M. K.; Fox, P. L.

1997-01-01

Ceruloplasmin is a 132-kDa glycoprotein abundant in human plasma. It has multiple in vitro activities, including copper transport, lipid pro- and antioxidant activity, and oxidation of ferrous ion and aromatic amines; however, its physiologic role is uncertain. Although ceruloplasmin is synthesized primarily by the liver in adult humans, production by cells of monocytic origin has been reported. We here show that IFN-gamma is a potent inducer of ceruloplasmin synthesis by monocytic cells. Activation of human monoblastic leukemia U937 cells with IFN-gamma increased the production of ceruloplasmin by at least 20-fold. The identity of the protein was confirmed by plasmin fingerprinting. IFN-gamma also increased ceruloplasmin mRNA. Induction followed a 2- to 4-h lag and was partially blocked by cycloheximide, indicating a requirement for newly synthesized factors. Ceruloplasmin induction in monocytic cells was agonist specific, as IL-1, IL-4, IL-6, IFN-alpha, IFN-beta, TNF-alpha, and LPS were completely ineffective. The induction was also cell type specific, as IFN-gamma did not induce ceruloplasmin synthesis in endothelial or smooth muscle cells. In contrast, IFN-gamma was stimulatory in other monocytic cells, including THP-1 cells and human peripheral blood monocytes, and also in HepG2 cells. Ceruloplasmin secreted by IFN-gamma-stimulated U937 cells had ferroxidase activity and was, in fact, the only secreted protein with this activity. Monocytic cell-derived ceruloplasmin may contribute to defense responses via its ferroxidase activity, which may drive iron homeostasis in a direction unfavorable to invasive organisms.

Monocyte recruitment and expression of monocyte chemoattractant protein-1 are developmentally regulated in remodeling bone in the mouse.

PubMed Central

Volejnikova, S.; Laskari, M.; Marks, S. C.; Graves, D. T.

1997-01-01

Tooth eruption is defined as the movement of a tooth from its site of development within the alveolar bone to its position of function in the oral cavity. It represents an excellent model to examine osseous metabolism as bone resorption and bone formation occur simultaneously and are spatially separated. Bone resorption occurs in the coronal (occlusal) area, whereas bone formation occurs in the basal area. Monocytes are thought to have a significant role in the regulation of osseous metabolism. The goal of this study was to examine the recruitment of monocytes to bone in C57BL/6J mice that are undergoing developmentally regulated bone remodeling. Monocytes were detected by immunohistochemistry and osteoclasts were counted as bone-associated multi-nucleated, tartrate-resistant acid phosphatase (TRAP)-positive cells. Cell numbers were obtained from histological sections of animals sacrificed daily for 14 days after birth; an image analysis system was used for quantification. The results demonstrated that, immediately after birth, there were relatively few monocytic cells. In the area of bone resorption, the number of monocytes increased with time, reaching peaks at 5 and 9 days, and decreased thereafter. A similar pattern was observed for osteoclasts. In the area of bone formation, there was a time-dependent increase in the number of monocytes. In contrast, the number of osteoclasts in this area was highest at the earliest time points and decreased after day 3. To investigate potential mechanisms for the recruitment of monocytes, expression of monocyte chemoattractant protein (MCP)-1 was assessed. The number of MCP-1-positive cells increased with time and was generally proportional to the recruitment of mononuclear phagocytes. Osteoblasts were the principal bone cell type expressing MCP-1. The results demonstrate that the recruitment of mononuclear cells in the occlusal area is associated with bone resorption. In contrast, recruitment of monocytes in the basal area is associated with bone formation and a decrease in the number of osteoclasts. These results suggest that monocytes have different functional roles in areas of bone formation compared with bone resorption. Furthermore, the expression of MCP-1 is developmentally regulated and may provide a mechanistic basis to explain the recruitment of monocytic cells. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9137095

Statins Inhibit Monocyte Chemotactic Protein 1 Expression in Endometriosis

PubMed Central

Cakmak, Hakan; Basar, Murat; Seval-Celik, Yasemin; Osteen, Kevin G.; Duleba, Antoni J.; Taylor, Hugh S.; Lockwood, Charles J.; Arici, Aydin

2012-01-01

Statins are potent inhibitors of the endogenous mevalonate pathway. Besides inhibiting cholesterol biosynthesis, statins may also demonstrate anti-inflammatory properties. Inflammation is implicated in the attachment and invasion of endometrial cells to the peritoneal surface and growth of ectopic endometrium by inducing proliferation and angiogenesis. In this study, the effect of statins on monocyte chemotactic protein 1 (MCP-1) expression in endometriotic implants in nude mouse model and in cultured endometriotic cells was evaluated. In mouse model, simvastatin decreased MCP-1 expression in a dose-dependent manner in endometriotic implants (P < .05). Similarly, both simvastatin and mevastatin revealed a dose-dependent inhibition of MCP-1 production in cultured endometriotic cells (P < .01). This inhibitory effect of the statins on MCP-1 production was reversed by the downstream substrates of the mevalonate pathway. Moreover, statins decreased MCP-1 messenger RNA expression in cultured endometriotic cells (P < .05). In conclusion, statins exert anti-inflammatory effect in endometriotic cells and could provide a potential treatment of endometriosis in the future. PMID:22267540

Resveratrol increases phagocytosis and lipopolysaccharide-induced interleukin-1β production, but decreases surface expression of Toll-like receptor 2 in THP-1 monocytes.

PubMed

Zunino, Susan J; Hwang, Daniel H; Huang, Shurong; Storms, David H

2018-02-01

THP-1 monocytes were used to evaluate the effects of physiological levels of resveratrol aglycone, resveratrol-3-O-glucuronide, resveratrol-4'-O-glucuronide, and resveratrol-3-O-sulfate on phagocytosis, IL-1β, IL-1α, and IL-18 production, viability, and TLR2 and TLR4 expression. THP-1 cells were treated with 1, 5, 10, and 15μM resveratrol or metabolites. Resveratrol-3-O-glucuronide, resveratrol-4'-O-glucuronide, and resveratrol-3-O-sulfate had no effect on the functional parameters tested. Resveratrol aglycone increased phagocytosis at concentrations of 5, 10, and 15μM and LPS-induced IL-1β production at concentrations of 10 and 15μM. Expression of TLR4 increased slightly after resveratrol treatment, but surface expression of TLR2 was reduced as resveratrol concentrations increased. Our data suggest that resveratrol may be effective in modulating monocyte function in an environment where there is direct exposure to the aglycone, such as at the gut epithelium. Published by Elsevier Ltd.

Effects of HIV infection and ART on phenotype and function of circulating monocytes, natural killer, and innate lymphoid cells.

PubMed

Nabatanzi, Rose; Cose, Stephen; Joloba, Moses; Jones, Sarah Rowland; Nakanjako, Damalie

2018-03-15

HIV infection causes upregulation of markers of inflammation, immune activation and apoptosis of host adaptive, and innate immune cells particularly monocytes, natural killer (NK) and innate lymphoid cells (ILCs). Although antiretroviral therapy (ART) restores CD4 T-cell counts, the persistent aberrant activation of monocytes, NK and ILCs observed likely contributes to the incomplete recovery of T-cell effector functions. A better understanding of the effects of HIV infection and ART on the phenotype and function of circulating monocytes, NK, and ILCs is required to guide development of novel therapeutic interventions to optimize immune recovery.

Presence of estrogen receptors in human myeloid monocytic cells (THP-1 cell line).

PubMed

Cutolo, M; Villaggio, B; Bisso, A; Sulli, A; Coviello, D; Dayer, J M

2001-01-01

To test THP-1 cells for the presence of estrogen receptors (ER) since studies have demonstrated in vivo and in vitro, the influence of estrogens on cells involved in immune response (i.e. macrophages), and since it has been demonstrated that human myeloid monocytic THP-1 cells acquire phenotypic and functional macrophage-like features after incubation with several cytokines or pharmacological agents. Stimulation of THP-1 cells with phorbol myristate acetate (PMA) to prompt their differentiation into macrophage-like cells and evaluation of the possible induction of ER. The expression of ER was analyzed by immunocytochemical assay, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. After stimulation by PMA, the human myeloid monocytic THP-1 cells showed the presence of ER, together with markers of monocytic cell differentiation such as CD68, CD54 and HLA-DR. Estrogen effects may be exerted directly through ER on monocytes/macrophages. PMA-treated THP-1 cells may constitute a useful in vitro model to determine the effects of estrogens on macrophage-like cells and their implications in the inflammatory and immune processes.

Effects of peritoneal fluid from endometriosis patients on the release of monocyte-specific chemokines by leukocytes.

PubMed

Na, Yong-Jin; Lee, Dong-Hyung; Kim, Seung-Chul; Joo, Jong-Kil; Wang, Ji-Won; Jin, Jun-O; Kwak, Jong-Young; Lee, Kyu-Sup

2011-06-01

Chemokines have been implicated in the pathological process of endometriosis. We compared the effects of peritoneal fluid obtained from patients with endometriosis (ePF) and controls without endometriosis (cPF) on the release of monocyte-specific CC chemokines such as monocyte chemotactic protein-1 (MCP-1), regulated upon activation normal T cell expressed and secreted (RANTES), and macrophage inflammatory protein-1α (MIP-1α) by neutrophils, monocytes, and T cells. Moreover, we evaluated the correlation between the levels of chemokines in ePF and their release by these cells. Cells were obtained from healthy young volunteers and cultured with ePF (n = 12) or cPF (n = 8). The chemokine levels in the ePF and the supernatants of cultured cells with ePF were then measured by ELISA. There was a positive correlation between the levels of MCP-1 and MIP-1α in ePF. The addition of ePF to the cell cultures failed to increase the release of MCP-1, RANTES, and MIP-1α when compared to cPF, but the levels of RANTES in ePF were positively correlated with the release of RANTES by ePF-treated monocytes and T cells. Moreover, there was a positive correlation between the levels of RANTES and MIP-1α released by neutrophils and between the levels of MCP-1 and MIP-1α released by T cells. Finally, the levels of RANTES released by monocyte-derived macrophages and monocytes cultured with ePF were positively correlated. These findings suggest that monocytes, neutrophils, and T cells release differential levels of MCP-1, RANTES, and MIP-1α in response to stimulation with ePF.

Histaminergic regulation of interferon-gamma (IFN-γ) production by human natural killer (NK) cells

PubMed Central

ASEA, A; HANSSON, M; CZERKINSKY, C; HOUZE, T; HERMODSSON, S; STRANNEGÅRD, Ö; HELLSTRAND, K

1996-01-01

Monocytes, recovered from human peripheral blood by counter-current centrifugal elutriation, effectively inhibit the production of IFN-γ by CD3−/56+ NK cells in response to IL-2. This study aimed at defining the nature of the inhibitory signal, particularly the importance of monocyte-derived reactive metabolites of oxygen. It was found that monocytes recovered from patients with chronic granulomatous disease (CGD), a condition characterized by deficient NADPH-oxidase activity of phagocytes, did not inhibit IFN-γ production by NK cells. Further, catalase, a scavenger of hydrogen peroxide, completely reversed the inhibitory signal, whereas scavengers of the superoxide anion, hypohalous acids, the hydroxyl radical, or nitric oxide synthesis inhibitors such as L-NMMA were ineffective. Inhibition of IFN-γ production was operating on a pre-translational level, as indicated by the inability of enriched NK cells to accumulate IFN-γ mRNA in the presence of elutriated monocytes. Hydrogen peroxide, at micromolar concentrations, reconstituted the inhibition of IFN-γ production when added to enriched NK cells. Histamine, a biogenic amine which inhibits the generation of reactive oxygen metabolites in monocytes, abrogated the inhibition of IFN-γ production in NK cells; by this mechanism, histamine strongly synergized with IL-2 to induce IFN-γ in mixtures of NK cells and monocytes. The synergizing effect of histamine was specifically mediated by H2-type histamine receptors. We conclude that: (i) the induction of IFN-γ mRNA in NK cells is effectively down-regulated by products of the oxidative metabolism of monocytes; and (ii) histamine effectively enhances IFN-γ production by preventing monocyte-induced oxidative damage to NK cells. PMID:8706348

Histaminergic regulation of interferon-gamma (IFN-gamma) production by human natural killer (NK) cells.

PubMed

Asea, A; Hansson, M; Czerkinsky, C; Houze, T; Hermodsson, S; Strannegård, O; Hellstrand, K

1996-08-01

Monocytes, recovered from human peripheral blood by counter-current centrifugal elutriation, effectively inhibit the production of IFN-gamma by CD3-/56+ NK cells in response to IL-2. This study aimed at defining the nature of the inhibitory signal, particularly the importance of monocyte-derived reactive metabolites of oxygen. It was found that monocytes recovered from patients with chronic granulomatous disease (CGD), a condition characterized by deficient NADPH-oxidase activity of phagocytes, did not inhibit IFN-gamma production by NK cells. Further, catalase, a scavenger of hydrogen peroxide, completely reversed the inhibitory signal whereas scavengers of the superoxide anion, hypohalous acids, the hydroxyl radical, or nitric oxide synthesis inhibitors such as L-NMMA were ineffective. Inhibition of IFN-gamma production was operating on a pretranslational level, as indicated by the inability of enriched NK cells to accumulate IFN-gamma mRNA in the presence of elutriated monocytes. Hydrogen peroxide, at micromolar concentrations, reconstituted the inhibition of IFN-gamma production when added to enriched NK cells. Histamine, a biogenic amine which inhibits the generation of reactive oxygen metabolites in monocytes, abrogated the inhibition of IFN-gamma production in NK cells; by this mechanism, histamine strongly synergized with IL-2 to induce IFN-gamma in mixtures of NK cells and monocytes. The synergizing effect of histamine was specifically mediated by H2-type histamine receptors. We conclude that: (i) the induction of IFN-gamma mRNA in NK cells is effectively down-regulated by products of the oxidative metabolism of monocytes; and (ii) histamine effectively enhances IFN-gamma production by preventing monocyte-induced oxidative damage to NK cells.

Interaction of THP-1 Monocytes with Conidia and Hyphae of Different Curvularia Strains

PubMed Central

Tóth, Eszter Judit; Boros, Éva; Hoffmann, Alexandra; Szebenyi, Csilla; Homa, Mónika; Nagy, Gábor; Vágvölgyi, Csaba; Nagy, István; Papp, Tamás

2017-01-01

Interaction of the human monocytic cell line, THP-1 with clinical isolates of three Curvularia species were examined. Members of this filamentous fungal genus can cause deep mycoses emerging in both immunocompromised and immunocompetent patients. It was found that monocytes reacted only to the hyphal form of Curvularia lunata. Cells attached to the germ tubes and hyphae and production of elevated levels of interleukin (IL)-8 and IL-10 and a low level of TNF-α were measured. At the same time, monocytes failed to produce IL-6. This monocytic response, especially with the induction of the anti-inflammatory IL-10, correlates well to the observation that C. lunata frequently cause chronic infections even in immunocompetent persons. Despite the attachment to the hyphae, monocytes could not reduce the viability of the fungus and the significant decrease in the relative transcript level of HLA-DRA assumes the lack of antigen presentation of the fungus by this cell type. C. spicifera and C. hawaiiensis failed to induce the gathering of the cells or the production of any analyzed cytokines. Monocytes did not recognize conidia of Curvularia species, even when melanin was lacking in their cell wall. PMID:29093719

Interaction of THP-1 Monocytes with Conidia and Hyphae of Different Curvularia Strains.

PubMed

Tóth, Eszter Judit; Boros, Éva; Hoffmann, Alexandra; Szebenyi, Csilla; Homa, Mónika; Nagy, Gábor; Vágvölgyi, Csaba; Nagy, István; Papp, Tamás

2017-01-01

Interaction of the human monocytic cell line, THP-1 with clinical isolates of three Curvularia species were examined. Members of this filamentous fungal genus can cause deep mycoses emerging in both immunocompromised and immunocompetent patients. It was found that monocytes reacted only to the hyphal form of Curvularia lunata . Cells attached to the germ tubes and hyphae and production of elevated levels of interleukin (IL)-8 and IL-10 and a low level of TNF-α were measured. At the same time, monocytes failed to produce IL-6. This monocytic response, especially with the induction of the anti-inflammatory IL-10, correlates well to the observation that C. lunata frequently cause chronic infections even in immunocompetent persons. Despite the attachment to the hyphae, monocytes could not reduce the viability of the fungus and the significant decrease in the relative transcript level of HLA-DRA assumes the lack of antigen presentation of the fungus by this cell type. C. spicifera and C. hawaiiensis failed to induce the gathering of the cells or the production of any analyzed cytokines. Monocytes did not recognize conidia of Curvularia species, even when melanin was lacking in their cell wall.

Endogenous pyrogen production by human blood monocytes stimulated by staphylococcal cell wall components.

PubMed

Oken, M M; Peterson, P K; Wilkinson, B J

1981-01-01

To determine the properties of Staphylococcus aureus contributing to its pyrogenicity, we compared, in human monocytes, endogenous pyrogen production stimulated by heat-killed S. aureus with that stimulated by purified S. aureus cell walls or by particulate peptidoglycan prepared from the same strain. Peptidoglycan, but not the purified cell wall preparation, was found comparable to S. aureus as an endogenous pyrogen stimulus. This finding was associated with a more effective monocyte phagocytosis of S. aureus and peptidoglycan as compared with that of purified cell walls. Lysostaphin digestion of peptidoglycan markedly reduced its pyrogenicity. To test whether the chemical composition of the ingested particles is important, latex particles were tested as possible stimuli for monocyte endogenous pyrogen release. Although 40 to 68% of monocytes ingested latex particles during the first hour, there was no evidence of endogenous pyrogen activity in the supernatant even when supernatants equivalent to 5.2 X 10(6) monocytes were tested. This study demonstrates that the pyrogenic moiety of the S. aureus cell wall resides in the peptidoglycan component. Phagocytosis is not in itself a pyrogenic stimulus, but rather serves as an effective mechanism to bring about contact between the chemical stimulus and the monocyte.

Human intestinal pro-inflammatory CD11chighCCR2+CX3CR1+ macrophages, but not their tolerogenic CD11c-CCR2-CX3CR1- counterparts, are expanded in inflammatory bowel disease.

PubMed

Bernardo, D; Marin, A C; Fernández-Tomé, S; Montalban-Arques, A; Carrasco, A; Tristán, E; Ortega-Moreno, L; Mora-Gutiérrez, I; Díaz-Guerra, A; Caminero-Fernández, R; Miranda, P; Casals, F; Caldas, M; Jiménez, M; Casabona, S; De la Morena, F; Esteve, M; Santander, C; Chaparro, M; Gisbert, J P

2018-05-09

Although macrophages (Mϕ) maintain intestinal immune homoeostasis, there is not much available information about their subset composition, phenotype and function in the human setting. Human intestinal Mϕ (CD45 + HLA-DR + CD14 + CD64 + ) can be divided into subsets based on the expression of CD11c, CCR2 and CX3CR1. Monocyte-like cells can be identified as CD11c high CCR2 + CX3CR1 + cells, a phenotype also shared by circulating CD14 + monocytes. On the contrary, their Mϕ-like tissue-resident counterparts display a CD11c - CCR2 - CX3CR1 - phenotype. CD11c high monocyte-like cells produced IL-1β, both in resting conditions and after LPS stimulation, while CD11c - Mϕ-like cells produced IL-10. CD11c high pro-inflammatory monocyte-like cells, but not the others, were increased in the inflamed colon from patients with inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis. Tolerogenic IL-10-producing CD11c - Mϕ-like cells were generated from monocytes following mucosal conditioning. Finally, the colonic mucosa recruited circulating CD14 + monocytes in a CCR2-dependent manner, being such capacity expanded in IBD. Mϕ subsets represent, therefore, transition stages from newly arrived pro-inflammatory monocyte-like cells (CD11c high CCR2 + CX3CR1 + ) into tolerogenic tissue-resident (CD11c - CCR2 - CX3CR1 - ) Mϕ-like cells as reflected by the mucosal capacity to recruit circulating monocytes and induce CD11c - Mϕ. The process is nevertheless dysregulated in IBD, where there is an increased migration and accumulation of pro-inflammatory CD11c high monocyte-like cells.

Redefining Myeloid Cell Subsets in Murine Spleen

PubMed Central

Hey, Ying-Ying; Tan, Jonathan K. H.; O’Neill, Helen C.

2016-01-01

Spleen is known to contain multiple dendritic and myeloid cell subsets, distinguishable on the basis of phenotype, function and anatomical location. As a result of recent intensive flow cytometric analyses, splenic dendritic cell (DC) subsets are now better characterized than other myeloid subsets. In order to identify and fully characterize a novel splenic subset termed “L-DC” in relation to other myeloid cells, it was necessary to investigate myeloid subsets in more detail. In terms of cell surface phenotype, L-DC were initially characterized as a CD11bhiCD11cloMHCII−Ly6C−Ly6G− subset in murine spleen. Their expression of CD43, lack of MHCII, and a low level of CD11c was shown to best differentiate L-DC by phenotype from conventional DC subsets. A complete analysis of all subsets in spleen led to the classification of CD11bhiCD11cloMHCII−Ly6CloLy6G− cells as monocytes expressing CX3CR1, CD43 and CD115. Siglec-F expression was used to identify a specific eosinophil population, distinguishable from both Ly6Clo and Ly6Chi monocytes, and other DC subsets. L-DC were characterized as a clear subset of CD11bhiCD11cloMHCII−Ly6C−Ly6G− cells, which are CD43+, Siglec-F− and CD115−. Changes in the prevalence of L-DC compared to other subsets in spleens of mutant mice confirmed the phenotypic distinction between L-DC, cDC and monocyte subsets. L-DC development in vivo was shown to occur independently of the BATF3 transcription factor that regulates cDC development, and also independently of the FLT3L and GM-CSF growth factors which drive cDC and monocyte development, so distinguishing L-DC from these commonly defined cell types. PMID:26793192

Induction of an interleukin-1 receptor (IL-1R) on monocytic cells. Evidence that the receptor is not encoded by a T cell-type IL-1R mRNA.

PubMed

Spriggs, M K; Lioubin, P J; Slack, J; Dower, S K; Jonas, U; Cosman, D; Sims, J E; Bauer, J

1990-12-25

Primary human monocytes and the human monocytic cell line THP-1 were induced to express receptors for interleukin-1 alpha (IL-1 alpha) and IL-1 beta. Treatment of primary monocytes with dexamethasone resulted in a 10-fold increase in receptor number over untreated cells, to approximately 2,000 receptors/cell. Treatment of THP-1 cells with phorbol ester followed by prostaglandin E2 and dexamethasone resulted in the expression of approximately 30,000 receptors/cell. Competitive binding assays on THP-1 cells showed that both IL-1 alpha and IL-1 beta bind to the same receptor. The monocyte IL-1R is significantly smaller (63 kDa) than the T cell IL-1R (80 kDa) and is immunologically distinct. However, induction of monocytes and monocytic cell lines leads to the appearance of an abundant mRNA of approximately 5,000 bases which hybridizes to a cDNA probe from the T cell-type IL-1R. Sequence data obtained from a cDNA clone of this mRNA indicate that the message is identical to the T cell IL-1R mRNA throughout the coding region. A smaller mRNA, also homologous to the T cell IL-1R mRNA, accumulated in induced THP-1 cells and has a shorter 3'-untranslated region than the larger. Data are presented which suggest that neither form of this message encodes the 63-kDa IL-1R, but rather that this protein is the product of a separate nonhomologous mRNA.

Surface modification of biomaterials based on high-molecular polylactic acid and their effect on inflammatory reactions of primary human monocyte-derived macrophages: perspective for personalized therapy.

PubMed

Stankevich, Ksenia S; Gudima, Alexandru; Filimonov, Victor D; Klüter, Harald; Mamontova, Evgeniya M; Tverdokhlebov, Sergei I; Kzhyshkowska, Julia

2015-06-01

Polylactic acid (PLA) based implants can cause inflammatory complications. Macrophages are key innate immune cells that control inflammation. To provide higher biocompatibility of PLA-based implants with local innate immune cells their surface properties have to be improved. In our study surface modification technique for high-molecular PLA (MW=1,646,600g/mol) based biomaterials was originally developed and successfully applied. Optimal modification conditions were determined. Treatment of PLA films with toluene/ethanol=3/7 mixture for 10min with subsequent exposure in 0.001M brilliant green dye (BGD) solution allows to entrap approximately 10(-9)mol/cm(2) model biomolecules. The modified PLA film surface was characterized by optical microscopy, SERS, FT-IR, UV and TG/DTA/DSC analysis. Tensile strain of modified films was determined as well. The effect of PLA films modified with BGD on the inflammatory reactions of primary human monocyte-derived macrophages was investigated. We developed in vitro test-system by differentiating primary monocyte-derived macrophages on a coating material. Type 1 and type 2 inflammatory cytokines (TNFα, CCL18) secretion and histological biomarkers (CD206, stabilin-1) expression were analyzed by ELISA and confocal microscopy respectively. BGD-modified materials have improved thermal stability and good mechanical properties. However, BGD modifications induced additional donor-specific inflammatory reactions and suppressed tolerogenic phenotype of macrophages. Therefore, our test-system successfully demonstrated specific immunomodulatory effects of original and modified PLA-based biomaterials, and can be further applied for the examination of improved coatings for implants and identification of patient-specific reactions to implants. Copyright © 2015. Published by Elsevier B.V.

HIV-1 DNA burden dynamics in CD4 T cells and monocytes in patients undergoing a transient therapy interruption.

PubMed

Garbuglia, Anna Rosa; Calcaterra, Silvia; D'Offizi, Gianpiero; Topino, Simone; Narciso, Pasquale; Lillo, Flavia; Girardi, Enrico; Capobianchi, Maria Rosaria

2004-11-01

Replication-competent HIV, as well as HIV-1 DNA, has been detected in CD4 T cells and in monocytes during antiretroviral therapy (ART), indicating that these cells could represent an important viral reservoir. We measured HIV-1 DNA in monocytes and CD4 T cells in patients undergoing transient therapy interruption (TTI), to establish the dynamic of HIV-1 DNA burden and to find possible correlations with immune restoration and re-establishment of virological control after ART resumption. In most patients CD4 depletion and viral load rebound followed TTI. Rapid resumption of virological and immunological control was achieved after ART reintroduction. After TTI, in most cases a transient increase of both monocyte and CD4 HIV-1 DNA burden was observed. After ART reintroduction, both CD4 T cell and monocyte HIV-1 DNA copy number decreased, reaching baseline levels at the end of observation. At this time monocyte HIV-1 DNA burden was always undetectable, while CD4 T cell HIV-1 DNA burden was lower than at baseline. As CD4 T cell HIV-1 DNA values are independently associated with CD4 depletion, the increase of HIV-1 DNA burden in these cells after TTI is presumably due to acute infection, causing cell death. This is also supported by the pattern of 2-LTR appearance in these cells after TTI. HIV-1 DNA burden in monocytes and CD4 T cells show high correlation, suggesting reciprocal re-feeding of two cell populations. Repopulation by HIV these cells after TTI is temporary, and no significant changes of HIV-1 DNA burden were observed after ART resumption respect to pre-TTI period.

A high-fat meal promotes lipid-load and apolipoprotein B-48 receptor transcriptional activity in circulating monocytes.

PubMed

Varela, Lourdes M; Ortega, Almudena; Bermudez, Beatriz; Lopez, Sergio; Pacheco, Yolanda M; Villar, Jose; Abia, Rocio; Muriana, Francisco J G

2011-05-01

The postprandial metabolism of dietary fats results in the production of apolipoprotein B-48 (apoB48)-containing triglyceride-rich lipoproteins (TRLs), which cause rapid receptor-mediated macrophage lipid engorgement via the apoB48 cell surface receptor (apoB48R). Monocytes circulate together with apoB48-containing TRLs in the postprandial bloodstream and may start accumulating lipids even before their migration to tissues and differentiation to macrophages. We sought to determine whether circulating monocytes are equipped with apoB48R and whether, in the postprandial state, circulating monocytes accumulate lipids and modulate apoB48R transcriptional activity after intake of a high-fat meal. In a crossover design, we studied the effect of a high-fat meal on fasting and postprandial concentrations of triglycerides, free fatty acids, cholesterol, and insulin in 12 healthy men. TRLs and monocytes were freshly isolated at fasting, hourly until the postprandial peak, and at the late postprandial phase. TRLs were subjected to triglycerides, apoB48, and apolipoprotein B-100 analyses; and lipid accumulation and apoB48R mRNA expression levels were measured in monocytes. Monocytes showed a time-dependent lipid accumulation in response to the high-fat meal, which was paralleled by an increase in apoB48R mRNA expression levels. These effects were coincident only with an increase in apoB48-containing TRLs in the postprandial phase and were also observed ex vivo in freshly isolated monocytes incubated with apoB48-containing TRLs. In a setting of abundant plasma apoB48-containing TRLs, these findings highlight the role of dietary fat in inducing lipid accumulation and apoB48R gene transcription in circulating monocytes.

Immunophenotyping of Monocytes During Human Sepsis Shows Impairment in Antigen Presentation: A Shift Toward Nonclassical Differentiation and Upregulation of FcγRi-Receptor.

PubMed

Ferreira da Mota, Nadijane Valeria; Brunialti, Milena Karina Colo; Santos, Sidneia Sousa; Machado, Flavia Ribeiro; Assunçao, Murillo; de Azevedo, Luciano Cesar Pontes; Salomao, Reinaldo

2017-12-05

Monocytes and macrophages are pivotal in the host response to sepsis, recognizing the infecting microorganism and triggering an inflammatory response. These functions are, at least in part, modulated by the expression of cell surface receptors. We aimed to characterize the monocyte phenotype from septic patients during an ongoing sepsis process and its association with clinical outcomes. Sixty-one septic patients and 31 healthy volunteers (HVs) were enrolled in the study. Samples were obtained from patients at baseline (D0, N = 61), and after 7 (D7, N = 36) and 14 days of therapy (D14, N = 22). Monocytes from septic patients presented decreased expression of CD86, HLA-DR, CD200R, CCR2, CXCR2, and CD163 compared with HV monocytes. In contrast, the PD-1, PD-L1, CD206, CD64, and CD16 expression levels were upregulated in patients. HLA-DR, CD64, PD-1, and PD-L1 expression levels were higher in survivors than in nonsurvivors. Increased CD86, HLA-DR, and CXCR2 expression levels were observed in follow-up samples; in contrast, CD64 and CD16 GMFI decreased over time. In conclusion, monocytes from septic patients show antigen presentation impairment as characterized by decreased HLA-DR and costimulatory CD86 expression and increased PD-1 and PD-L1 expression. On the contrary, increased monocyte inflammatory and phagocytic activities may be inferred by the increased CD16 and CD64 expression. We found conflicting results regarding differentiation toward the M2 phenotype, with increased CD206 expression and decreased CD163 expression on monocytes from septic patients, whereas the subset of nonclassical monocytes was demonstrated by increased CD16.

Hemin controls T cell polarization in sickle cell alloimmunization.

PubMed

Zhong, Hui; Bao, Weili; Friedman, David; Yazdanbakhsh, Karina

2014-07-01

Patients with sickle cell disease (SCD) often require transfusions to treat and prevent worsening anemia and other SCD complications. However, transfusions can trigger alloimmunization against transfused RBCs with serious clinical sequelae. Risk factors for alloimmunization in SCD remain poorly understood. We recently reported altered regulatory T cell (Treg) and Th responses with higher circulating Th1 (IFN-γ(+)) cytokines in chronically transfused SCD patients with alloantibodies as compared with those without alloantibodies. Because monocytes play a critical role in polarization of T cell subsets and participate in clearance of transfused RBCs, we tested the hypothesis that in response to the RBC breakdown product hemin, monocyte control of T cell polarization will differ between alloimmunized and non-alloimmunized SCD patients. Exogenous hemin induced Treg polarization in purified T cell/monocyte cocultures from healthy volunteers through the monocyte anti-inflammatory heme-degrading enzyme heme oxygenase-1. Importantly, hemin primarily through its effect on CD16+ monocytes induced an anti-inflammatory (higher Treg/lower Th1) polarization state in the non-alloimmunized SCD group, whereas it had little effect in the alloimmunized group. Non-alloimmunized SCD CD16+ monocytes expressed higher basal levels of heme oxygenase-1. Furthermore, IL-12, which contributed to a proinflammatory polarization state (low Treg/high Th1) in SCD, was dampened in hemin-treated stimulated monocytes from non-alloimmunized SCD patients, but not in the alloimmunized group. These data suggest that unlike alloimmunized patients, non-alloimmunized SCD CD16+ monocytes in response to transfused RBC breakdown products promote an anti-inflammatory state that is less conducive to alloimmunization. Copyright © 2014 by The American Association of Immunologists, Inc.

Monocyte:T cell interaction regulates human T cell activation through a CD28/CD46 crosstalk

PubMed Central

Charron, Lauren; Doctrinal, Axelle; Choileain, Siobhan Ni; Astier, Anne L.

2015-01-01

T cell activation requires engagement of the T cell receptor and of at least one costimulatory molecule. The key role of CD28 in inducing T cell activation has been reported several decades ago and the molecular mechanisms involved well described. The complement regulator CD46 also acts as a costimulatory molecule for T cells but, in contrast to CD28, has the ability to drive T cell differentiation from producing some IFNγ to secreting some potent anti-inflammatory IL-10, acquiring a so-called Type I regulatory phenotype (Tr1). Proteolytic cleavage of CD46 occurs upon costimulation and is important for T cell activation and IL-10 production. The observation that CD46 cleavage was reduced when PBMC were costimulated compared to purified naive T cells led us to hypothesize that interactions between different cell types within the PBMC were able to modulate the CD46 pathway. We show that CD46 downregulation is also reduced when CD4+ T cells are co-cultured with autologous monocytes. Indeed, monocyte:T cell co-cultures impaired CD46–mediated T cell differentiation and coactivation, by reducing downregulation of surface CD46, lowering induction of the early activation marker CD69, as well as reducing the levels of IL-10 secretion. Blocking of CD86 could partly restore CD69 expression and cytokine secretion, demonstrating that the CD28-CD86 pathway regulates CD46 activation. Direct concomitant ligation of CD28 and CD46 on CD4+ T cells also modulated CD46 expression and regulated cytokine production. These data identify a crosstalk between two main costimulatory pathways and provide novel insights into the regulation of human T cell activation. PMID:25787182

Amine-Rich Organic Thin Films for Cell Culture: Possible Electrostatic Effects in Cell-Surface Interactions

NASA Astrophysics Data System (ADS)

Wertheimer, Michael R.; St-Georges-Robillard, Amélie; Lerouge, Sophie; Mwale, Fackson; Elkin, Bentsian; Oehr, Christian; Wirges, Werner; Gerhard, Reimund

2012-11-01

In recent communications from these laboratories, we observed that amine-rich thin organic layers are very efficient surfaces for the adhesion of mammalian cells. We prepare such deposits by plasma polymerization at low pressure, atmospheric pressure, or by vacuum-ultraviolet photo-polymerization. More recently, we have also investigated a commercially available material, Parylene diX AM. In this article we first briefly introduce literature relating to electrostatic interactions between cells, proteins, and charged surfaces. We then present certain selected cell-response results that pertain to applications in orthopedic and cardiovascular medicine: we discuss the influence of surface properties on the observed behaviors of two particular cell lines, human U937 monocytes, and Chinese hamster ovary cells. Particular emphasis is placed on possible electrostatic attractive forces due to positively charged R-NH3+ groups and negatively charged proteins and cells, respectively. Experiments carried out with electrets, polymers with high positive or negative surface potentials are added for comparison.

C-type natriuretic peptide is synthesized and secreted from leukemia cell lines, peripheral blood cells, and peritoneal macrophages.

PubMed

Kubo, A; Isumi, Y; Ishizaka, Y; Tomoda, Y; Kangawa, K; Dohi, K; Matsuo, H; Minamino, N

2001-05-01

C-type natriuretic peptide (CNP) is the third member of the natriuretic peptide family. Cultured endothelial cells secrete CNP, and its secretion rate from the endothelial cells is augmented by lipopolysaccharide, interleukin-1beta, and tumor necrosis factor-alpha, which participate in the pathophysiology of inflammation. In this study, we investigated the regulation of CNP secretion from monocytes and macrophages to estimate its contribution to the progression of inflammation. CNP secretion rates from two human leukemia cell lines (THP-1 and HL-60), human peripheral blood lymphocytes, granulocytes, monocytes, monocyte-derived macrophages, and mouse peritoneal macrophages were measured under conditions with or without stimulation. Immunoreactive CNP levels in the culture media of these cells were measured by a specific radioimmunoassay. The secretion rates of CNP from THP-1 and HL-60 cells were augmented according to the degree of their differentiation into macrophage-like cells under the stimulation with phorbol ester. Peripheral blood monocytes also increased the CNP secretion rate after their differentiation into macrophages. Retinoic acid elicited synergistic effects on the CNP secretion rate from HL-60 cells when administered with lipopolysaccharide, interferon-gamma, interleukin-1beta, tumor necrosis factor-alpha, or phorbol ester. In contrast, the phorbol ester-stimulated CNP secretion rate from THP-1 cells was suppressed with dexamethasone, which inhibits monocyte differentiation into macrophage. The secretion rate of CNP from monocytes was shown to be regulated based on the degree of their differentiation. This study provides evidence that the monocyte/macrophage system is one of the sources of CNP, especially under inflammatory conditions.

Effect and possible mechanism of monocyte-derived VEGF on monocyte-endothelial cellular adhesion after electrical burns.

PubMed

Ruan, Qiongfang; Zhao, Chaoli; Ye, Ziqing; Ruan, Jingjing; Xie, Qionghui; Xie, Weiguo

2015-06-01

One of the major obstacles in the treatment of severe electrical burns is properly handling the resulting uncontrolled inflammation. Such inflammation often causes secondary injury and necrosis, thus complicating patient outcomes. Vascular endothelial grow factor (VEGF) has emerged as an important mediator for the recruitment of monocytes to the site inflammation. This study was designed to explore the effects and possible mechanism of VEGF on monocyte-endothelial cellular adhesion. To do so, we used a cultured human monocytic cell line (THP-1) that was stimulated with serum derived from rats that had received electrical burns. Serum was obtained from rats that had received electrical burns. Both the VEGF and soluble flt-1 (sflt-1) concentrations of the serum were determined by double-antibody sandwich ELISA. The concentrations of VEGF, sflt-1, and TNF-α obtained from the cell-free cultured supernatant of THP-1 cells that had been exposed to the serum were then determined by double-antibody sandwich ELISA. Serum-stimulated THP-1 cells were added to wells with a monolayer of endothelial cells to detect the level of monocyte-endothelial cells adhesion. Finally, the state of phosphorylation of AKT was determined by Western blotting. Both in vivo and in vitro studies showed that compared to controls, the levels of VEGF were significantly increased after electrical burns. This increased was accompanied by a reduction of sflt-1 levels. Furthermore, the serum of rats that had received electrical burns was able to both activate monocytes to secrete TNF-α and enhance monocyte-endothelial cell adhesion. Treatment with the serum also resulted in an up-regulation of the phosphorylation of AKT, but had no effect on the total levels of AKT. Phosphatidylinositide 3-kinases (PI3K) inhibition decreased the number of THP-1 cells that were adhered to endothelial cells. Finally, sequestering VEGF with sflt-1 was able to reduce the effect on monocyte-endothelial cells adhesion by blocking the PI3K signaling pathway. Our results indicate that VEGF is implicated in the pathogenesis of inflammation after electrical burns. Inhibition of VEGF activity could attenuate monocyte-endothelial cells adhesion by suppressing the state of phosphorylation of AKT, which is downstream of the PI3K signaling pathway. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Reversible differentiation of human monoblastic leukemia U937 cells by ML-9, an inhibitor of myosin light chain kinase.

PubMed

Yamamoto-Yamaguchi, Y; Makishima, M; Kanatani, Y; Kasukabe, T; Honma, Y

1996-05-01

Human monoblastic leukemia U937 cells are induced to differentiate into monocytes and macrophages by various agents. We have shown that 1-(5-chloronaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine hydrochloride (ML-9), an inhibitor of myosin light chain kinase, induces differentiation of monocytoid leukemia cell lines U937 and THP-1 but not of myeloblastic leukemic ML-1 cell or erythroleukemia K562 cells. In the present study, we further analyzed the effect of ML-9 in comparison with that of 1 alpha, 25-dihydroxyvitamin D3 (VD3) a typical inducer of monocytic differentiation. ML-9 induced nitroblue tetrazolium (NBT)-reducing activity of U937 cell more rapidly than VD3: This differentiation marker was induced significantly after incubation with ML-9 and VD3 for 4 hours and 1 day, respectively. ML-9 also induced alpha-naphthyl acetate esterase (ANAE) activity, another monocytic differentiation marker, more rapidly than VD3. The maximum levels of these markers induced by ML-9 were comparable to those induced by VD3, but after removal of ML-9 from the medium by washing the cells, the expressions of theses markers decreased within 4 hours and reached basal levels in 1 day, indicating that ML-9's induction of expression of differentiation-associated phenotypes was reversible. The growth inhibition of U937 cells by ML-9 was also reversible. Similar effects were observed in another line of human monoblastic cells, THP-1. ML-9 had little or no effect on the morphology of U937 cells but increased the expression of monocyte-macrophage lineage-associated surface antigen, CD14, to some extent. Irreversible terminal differentiation induced by VD3 is associated with down regulation of the expression of c-myc and upregulation of the expression of c-fos and c-jun, but ML-9 did not affect the expression of these oncogenes appreciably. ML-9-induced differentiation was also reversible when the cells were cultured with cultured with ML-9 plus an anti-cancer drug such as 1-beta-D-arabino-furanosylcytosine or daunomycin. it became irreversible, however, upon simultaneous treatment with dexamethasone and transforming growth factor-beta 1 (TGF-beta 1), which did not induce differentiation of U937 cells but caused growth arrest of the cells in the G0/G1 phase of the cell cycle. These results suggest that ML-9 should be useful for studying the mechanisms of monocytic differentiation.

Effects of acute exercise on monocyte subpopulations in metabolic syndrome patients.

PubMed

Wonner, Ralph; Wallner, Stefan; Orsó, Evelyn; Schmitz, Gerd

2016-06-10

Acute exercise induces numerous changes in peripheral blood, e.g. counts of leukocytes. CD16 pos monocytes, which play a role in the pathogenesis of arteriosclerosis and the metabolic syndrome (MetS), are among the blood cells with the highest fold increase through exercise. So far no studies have investigated the effect of exercise on the blood cell composition of patients with MetS. Blood cell counts, a wide panel of laboratory tests, as well as lipid and protein content of monocytes and granulocytes were determined in healthy subjects, persons with metabolic risk and MetS patients before and after one minute of exercise at 400 W. Leukocyte counts increased significantly in all groups with CD14 pos CD16 pos monocytes showing the highest fold-change. In MetS patients the fold increase was smaller. They had a higher resting level of CD14 pos CD16 pos monocytes and a lower basal ratio of CD16 neg /CD16 pos monocytes. A similar ratio of these cells was induced in control and risk subjects after exercise. However, absolute counts of mobilized pro-inflammatory monocytes did not differ significantly. Furthermore, we detected a decrease in protein content of monocytes in controls, but not in MetS patients. As strenuous exercise is able to mobilize the same amount of pro-inflammatory monocytes in MetS patients as in healthy persons, the elevated basal level of these cells in MetS patients is likely to be caused by enhanced maturation rather than chronic mobilization. The removal of these monocytes from the endothelium might be part of the beneficial effect of exercise on vascular disease. © 2016 International Clinical Cytometry Society. © 2016 International Clinical Cytometry Society.

4F2 monoclonal antibody recognizes a surface antigen on spread human fibroblasts of embryonic but not of adult origin

PubMed Central

1984-01-01

The 4F2 monoclonal antibody (mAb) has been shown to recognize a 120- kilodalton glycoprotein expressed on the cell surface of human peripheral blood monocytes, activated (but not resting) T or B cells, and T and B lymphoblastoid cell lines. In this report we show that 4F2 mAb specifically binds to the surface of adherent human embryonic fibroblasts but fails to bind to normal adult fibroblasts. Moreover, 4F2 antigen was expressed on sarcoma-derived or SV40-transformed adult fibroblastic cells. Finally, addition of 4F2 mAb inhibited the growth of cultured HT-1080 fibrosarcoma cell line, but had no inhibitory effect on various embryonic and adult normal or transformed fibroblasts. PMID:6538202

Culture of Macrophage Colony-stimulating Factor Differentiated Human Monocyte-derived Macrophages.

PubMed

Jin, Xueting; Kruth, Howard S

2016-06-30

A protocol is presented for cell culture of macrophage colony-stimulating factor (M-CSF) differentiated human monocyte-derived macrophages. For initiation of experiments, fresh or frozen monocytes are cultured in flasks for 1 week with M-CSF to induce their differentiation into macrophages. Then, the macrophages can be harvested and seeded into culture wells at required cell densities for carrying out experiments. The use of defined numbers of macrophages rather than defined numbers of monocytes to initiate macrophage cultures for experiments yields macrophage cultures in which the desired cell density can be more consistently attained. Use of cryopreserved monocytes reduces dependency on donor availability and produces more homogeneous macrophage cultures.

Automated single cell sorting and deposition in submicroliter drops

NASA Astrophysics Data System (ADS)

Salánki, Rita; Gerecsei, Tamás; Orgovan, Norbert; Sándor, Noémi; Péter, Beatrix; Bajtay, Zsuzsa; Erdei, Anna; Horvath, Robert; Szabó, Bálint

2014-08-01

Automated manipulation and sorting of single cells are challenging, when intact cells are needed for further investigations, e.g., RNA or DNA sequencing. We applied a computer controlled micropipette on a microscope admitting 80 PCR (Polymerase Chain Reaction) tubes to be filled with single cells in a cycle. Due to the Laplace pressure, fluid starts to flow out from the micropipette only above a critical pressure preventing the precise control of drop volume in the submicroliter range. We found an anomalous pressure additive to the Laplace pressure that we attribute to the evaporation of the drop. We have overcome the problem of the critical dropping pressure with sequentially operated fast fluidic valves timed with a millisecond precision. Minimum drop volume was 0.4-0.7 μl with a sorting speed of 15-20 s per cell. After picking NE-4C neuroectodermal mouse stem cells and human primary monocytes from a standard plastic Petri dish we could gently deposit single cells inside tiny drops. 94 ± 3% and 54 ± 7% of the deposited drops contained single cells for NE-4C and monocytes, respectively. 7.5 ± 4% of the drops contained multiple cells in case of monocytes. Remaining drops were empty. Number of cells deposited in a drop could be documented by imaging the Petri dish before and after sorting. We tuned the adhesion force of cells to make the manipulation successful without the application of microstructures for trapping cells on the surface. We propose that our straightforward and flexible setup opens an avenue for single cell isolation, critically needed for the rapidly growing field of single cell biology.

Saquinavir inhibits early events associated with establishment of HIV-1 infection: potential role for protease inhibitors in prevention.

PubMed

Stefanidou, Martha; Herrera, Carolina; Armanasco, Naomi; Shattock, Robin J

2012-08-01

The maturation of newly formed human immunodeficiency virus type 1 (HIV-1) virions is a critical step for the establishment of productive infection. We investigated the potential of saquinavir (SQV), a protease inhibitor (PI) used in highly active antiretroviral therapy (HAART), as a candidate microbicide. SQV inhibited replication of clade B and clade C isolates in a dose-dependent manner in all cellular models tested: PM-1 CD4 T cells, peripheral blood mononuclear cells (PBMCs), monocyte-derived macrophages (MDMs), and immature monocyte-derived dendritic cells (iMDDCs). SQV also inhibited production of infectious virus in cervical, penile, and colorectal explants cocultured with T cells. Moreover, SQV demonstrated inhibitory potency against trans infection of T cells by in vitro-derived dendritic cells and by primary dendritic cells that emigrate from penile and cervical tissue explants. No cellular or tissue toxicity was detected in the presence of SQV, suggesting that this drug could be considered for development as a component of an effective microbicide, capable of blocking viral maturation and transmission of HIV-1 at mucosal surfaces.

Mycobacterium leprae upregulates IRGM expression in monocytes and monocyte-derived macrophages.

PubMed

Yang, Degang; Chen, Jia; Zhang, Linglin; Cha, Zhanshan; Han, Song; Shi, Weiwei; Ding, Ru; Ma, Lan; Xiao, Hong; Shi, Chao; Jing, Zhichun; Song, Ningjing

2014-08-01

Leprosy is caused by the infection of Mycobacterium leprae, which evokes a strong inflammatory response and leads to nerve damage. Immunity-related GTPase family M protein (IRGM) plays critical roles in controlling inflammation. The objective of the study was to investigate whether IRGM is involved in the infection of M. leprae. Levels of IRGM were assessed in M. leprae-infected CD4(+) T cells, monocytes, and monocyte-derived macrophages. Data revealed that both protein and mRNA levels of IRGM were increased in monocytes after M. leprae infection. Interestingly, monocyte-derived macrophages showed more prominent IRGM expression with M. leprae infection, whereas the bacteria did not affect IRGM in CD4(+) T cells. Furthermore, we assessed levels of IRGM in CD4(+) T cells and monocytes from 78 leprosy patients and 40 healthy controls, and observed upregulated protein level of IRGM in the monocytes from leprosy patients. Also, IRGM expression was inversely correlated with the severity of the disease. These findings suggested a close involvement of IRGM in M. leprae infection and indicated a potential mechanism of defending M. leprae infection.

STAT3 activation in monocytes accelerates liver cancer progression.

PubMed

Wu, Wen-Yong; Li, Jun; Wu, Zheng-Sheng; Zhang, Chang-Le; Meng, Xiang-Ling

2011-12-05

Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor ubiquitously expressed in different cell types. STAT3 plays an essential role in cell survival, proliferation, and differentiation. Aberrantly hyper-activated STAT3 signaling in cancer cells and in the tumor microenvironment has been detected in a wide variety of human cancers and is considered an important factor for cancer initiation, development, and progression. However, the role of STAT3 activation in monocytes in the development of HCC has not been well understood. Immunohistochemical analysis of phosphorylated STAT3 was performed on tissue microarray from HCC patients. Using a co-culture system in vivo, HCC cell growth was determined by the MTT assay. In vivo experiments were conducted with mice given diethylinitrosamine (DEN), which induces HCC was used to investigate the role of STAT3 expression in monocytes on tumor growth. Real-time PCR was used to determine the expression of cell proliferation and cell arrest associated genes in the tumor and nontumor tissue from liver. Phosphorylated STAT3 was found in human hepatocellular carcinoma tissue samples and was expressed in tumor cells and also in monocytes. Phosphorylated STAT3 expression in monocyte was significantly correlated to advanced clinical stage of HCC and a poor prognosis. Using a co-culture system in vivo, monocytes promoted HCC cell growth via the IL-6/STAT3 signaling pathway. The STAT3 inhibitor, NSC 74859, significantly suppressed tumor growth in vivo in mice with diethylinitrosamine (DEN)-induced HCC. In this animal model, blockade of STAT3 with NSC 74859 induced tumor cell apoptosis, while inhibiting both tumor cells and monocytes proliferation. Furthermore, NSC 74859 treatment suppressed cancer associated inflammation in DEN-induce HCC. Our data suggest constitutively activated STAT3 monocytes promote liver tumorigenesis in clinical patients and animal experiments. Thus, STAT3 in tumor infiltrating inflammatory cells may an attractive target for liver cancer therapy.

Immortalized porcine mesenchymal cells derived from nasal mucosa, lungs, lymph nodes, spleen and bone marrow retain their stemness properties and trigger the expression of siglec-1 in co-cultured blood monocytic cells

PubMed Central

Garba, Abubakar; Desmarets, Lowiese M. B.; Acar, Delphine D.; Devriendt, Bert; Nauwynck, Hans J.

2017-01-01

Mesenchymal stromal cells have been isolated from different sources. They are multipotent cells capable of differentiating into many different cell types, including osteocytes, chondrocytes and adipocytes. They possess a therapeutic potential in the management of immune disorders and the repair of damaged tissues. Previous work in our laboratory showed an increase of the percentages of CD172a+, CD14+, CD163+, Siglec-1+, CD4+ and CD8+ hematopoietic cells, when co-cultured with immortalized mesenchymal cells derived from bone marrow. The present work aimed to demonstrate the stemness properties of SV40-immortalized mesenchymal cells derived from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow and their immunomodulatory effect on blood monocytes. Mesenchymal cells from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow were isolated and successfully immortalized using simian virus 40 large T antigen (SV40LT) and later, co-cultured with blood monocytes, in order to examine their differentiation stage (expression of Siglec-1). Flow cytometric analysis revealed that the five mesenchymal cell lines were positive for mesenchymal cell markers CD105, CD44, CD90 and CD29, but lacked the expression of myeloid cell markers CD16 and CD11b. Growth analysis of the cells demonstrated that bone marrow derived-mesenchymal cells proliferated faster compared with those derived from the other tissues. All five mesenchymal cell lines co-cultured with blood monocytes for 1, 2 and 7 days triggered the expression of siglec-1 in the monocytes. In contrast, no siglec-1+ cells were observed in monocyte cultures without mesenchymal cell lines. Mesenchymal cells isolated from nasal mucosa, lungs, spleen, lymph nodes and bone marrow were successfully immortalized and these cell lines retained their stemness properties and displayed immunomodulatory effects on blood monocytes. PMID:29036224

Immortalized porcine mesenchymal cells derived from nasal mucosa, lungs, lymph nodes, spleen and bone marrow retain their stemness properties and trigger the expression of siglec-1 in co-cultured blood monocytic cells.

PubMed

Garba, Abubakar; Desmarets, Lowiese M B; Acar, Delphine D; Devriendt, Bert; Nauwynck, Hans J

2017-01-01

Mesenchymal stromal cells have been isolated from different sources. They are multipotent cells capable of differentiating into many different cell types, including osteocytes, chondrocytes and adipocytes. They possess a therapeutic potential in the management of immune disorders and the repair of damaged tissues. Previous work in our laboratory showed an increase of the percentages of CD172a+, CD14+, CD163+, Siglec-1+, CD4+ and CD8+ hematopoietic cells, when co-cultured with immortalized mesenchymal cells derived from bone marrow. The present work aimed to demonstrate the stemness properties of SV40-immortalized mesenchymal cells derived from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow and their immunomodulatory effect on blood monocytes. Mesenchymal cells from nasal mucosa, lungs, spleen, lymph nodes and red bone marrow were isolated and successfully immortalized using simian virus 40 large T antigen (SV40LT) and later, co-cultured with blood monocytes, in order to examine their differentiation stage (expression of Siglec-1). Flow cytometric analysis revealed that the five mesenchymal cell lines were positive for mesenchymal cell markers CD105, CD44, CD90 and CD29, but lacked the expression of myeloid cell markers CD16 and CD11b. Growth analysis of the cells demonstrated that bone marrow derived-mesenchymal cells proliferated faster compared with those derived from the other tissues. All five mesenchymal cell lines co-cultured with blood monocytes for 1, 2 and 7 days triggered the expression of siglec-1 in the monocytes. In contrast, no siglec-1+ cells were observed in monocyte cultures without mesenchymal cell lines. Mesenchymal cells isolated from nasal mucosa, lungs, spleen, lymph nodes and bone marrow were successfully immortalized and these cell lines retained their stemness properties and displayed immunomodulatory effects on blood monocytes.

Silencing or inhibition of endoplasmic reticulum aminopeptidase 1 (ERAP1) suppresses free heavy chain expression and Th17 responses in ankylosing spondylitis

PubMed Central

Chen, Liye; Ridley, Anna; Hammitzsch, Ariane; Al-Mossawi, Mohammad Hussein; Bunting, Helen; Georgiadis, Dimitris; Chan, Antoni; Kollnberger, Simon; Bowness, Paul

2016-01-01

Objective Human leucocyte antigen (HLA)-B27 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly associated with ankylosing spondylitis (AS). ERAP1 is a key aminopeptidase in HLA class I presentation and can potentially alter surface expression of HLA-B27 free heavy chains (FHCs). We studied the effects of ERAP1 silencing/inhibition/variations on HLA-B27 FHC expression and Th17 responses in AS. Methods Flow cytometry was used to measure surface expression of HLA class I in peripheral blood mononuclear cells (PBMCs) from patients with AS carrying different ERAP1 genotypes (rs2287987, rs30187 and rs27044) and in ERAP1-silenced/inhibited/mutated HLA-B27-expressing antigen presenting cells (APCs). ERAP1-silenced/inhibited APCs were cocultured with KIR3DL2CD3ε-reporter cells or AS CD4+ T cells. Th17 responses of AS CD4+ T cells were measured by interleukin (IL)-17A ELISA and Th17 intracellular cytokine staining. FHC cell surface expression and Th17 responses were also measured in AS PBMCs following ERAP1 inhibition. Results The AS-protective ERAP1 variants, K528R and Q730E, were associated with reduced surface FHC expression by monocytes from patients with AS and HLA-B27-expressing APCs. ERAP1 silencing or inhibition in APCs downregulated HLA-B27 FHC surface expression, reduced IL-2 production by KIR3DL2CD3ε-reporter cells and suppressed the Th17 expansion and IL-17A secretion by AS CD4+ T cells. ERAP1 inhibition of AS PBMCs reduced HLA class I FHC surface expression by monocytes and B cells, and suppressed Th17 expansion. Conclusions ERAP1 activity determines surface expression of HLA-B27 FHCs and potentially promotes Th17 responses in AS through binding of HLA-B27 FHCs to KIR3DL2. Our data suggest that ERAP1 inhibition has potential for AS treatment. PMID:26130142

Annexin 1 Modulates Monocyte-Endothelial Cell Interaction In Vitro and Cell Migration In Vivo in the Human SCID Mouse Transplantation Model1

PubMed Central

Perretti, Mauro; Ingegnoli, Francesca; Wheller, Samantha K.; Blades, Mark C.; Solito, Egle; Pitzalis, Costantino

2015-01-01

The effect of the glucocorticoid inducible protein annexin 1 (ANXA1) on the process of monocytic cell migration was studied using transfected U937 cells expressing variable protein levels. An antisense (AS) (36.4AS; ~50% less ANXA1) and a sense (S) clone (15S; overexpressing the bioactive 24-kDa fragment) together with the empty plasmid CMV clone were obtained and compared with wild-type U937 cells in various models of cell migration in vitro and in vivo. 15S-transfected U937 cells displayed a reduced (50%) degree of trans-endothelial migration in response to stromal cell-derived factor-1α (CXC chemokine ligand 12 (CXCL12)). In addition, the inhibitory role of endogenous ANXA1 on U937 cell migration in vitro was confirmed by the potentiating effect of a neutralizing anti-ANXA1 serum. Importantly, overexpression of ANXA1 in clone 15S inhibited the extent of cell migration into rheumatoid synovial grafts transplanted into SCID mice. ANXA1 inhibitory effects were not due to modifications in adhesion molecule or CXCL12 receptor (CXCR4) expression as shown by the similar amounts of surface molecules found in transfected and wild-type U937 cells. Likewise, an equal chemotactic response to CXCL12 in vitro excluded an intrinsic defect in cell motility in clones 15S and 36.4AS. These data strongly support the notion that ANXA1 critically interferes with a leukocyte endothelial step essential for U937 cell, and possibly monocyte, transmigration both in vitro and in vivo. PMID:12165536

Cancer Cell-derived Exosomes Induce Mitogen-activated Protein Kinase-dependent Monocyte Survival by Transport of Functional Receptor Tyrosine Kinases*

PubMed Central

Song, Xiao; Ding, Yanping; Liu, Gang; Yang, Xiao; Zhao, Ruifang; Zhang, Yinlong; Zhao, Xiao; Anderson, Gregory J.; Nie, Guangjun

2016-01-01

Tumor-associated macrophages (TAM) play pivotal roles in cancer initiation and progression. Monocytes, the precursors of TAMs, normally undergo spontaneous apoptosis within 2 days, but can subsist in the inflammatory tumor microenvironment for continuous survival and generation of sufficient TAMs. The mechanisms underlying tumor-driving monocyte survival remain obscure. Here we report that cancer cell-derived exosomes were crucial mediators for monocyte survival in the inflammatory niche. Analysis of the survival-promoting molecules in monocytes revealed that cancer cell-derived exosomes activated Ras and extracellular signal-regulated kinases in the mitogen-activated protein kinase (MAPK) pathway, resulting in the prevention of caspase cleavage. Phosphorylated receptor tyrosine kinases (RTKs), such as phosphorylated epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2), were abundantly expressed in cancer cell-derived exosomes. Knock-out of EGFR or/and HER-2, or alternatively, inhibitors against their phosphorylation significantly disturbed the exosome-mediated activation of the MAPK pathway, inhibition of caspase cleavage, and increase in survival rate in monocytes. Moreover, the deprived survival-stimulating activity of exosomes due to null expression of EGFR and HER-2 could be restored by activation of another RTK, insulin receptor. Overall, our study uncovered a mechanism of tumor-associated monocyte survival and demonstrated that cancer cell-derived exosomes can stimulate the MAPK pathway in monocytes through transport of functional RTKs, leading to inactivation of apoptosis-related caspases. This work provides insights into the long sought question on monocyte survival prior to formation of plentiful TAMs in the tumor microenvironment. PMID:26895960

Functional relevance of protein glycosylation to the pro-inflammatory effects of extracellular matrix metalloproteinase inducer (EMMPRIN) on monocytes/macrophages.

PubMed

Ge, Heng; Yuan, Wei; Liu, Jidong; He, Qing; Ding, Song; Pu, Jun; He, Ben

2015-01-01

Extracellular matrix metalloproteinase inducer (EMMPRIN) is an important pro-inflammatory protein involved in the cellular functions of monocytes/macrophages. We have hypothesized that high-level heterogeneousness of protein glycosylation of EMMPRIN may have functional relevance to its biological effects and affect the inflammatory activity of monocytes/macrophages. The glycosylation patterns of EMMPRIN expressed by monocytes/macrophages (THP-1 cells) in response to different extracellular stimuli were observed, and the structures of different glycosylation forms were identified. After the purification of highly- and less-glycosylated proteins respectively, the impacts of different glycosylation forms on the pro-inflammatory effects of EMMPRIN were examined in various aspects, such as cell adhesion to endothelial cells, cell migrations, cytokine expression, and activation of inflammatory signalling pathway. 1) It was mainly the highly-glycosylated form of EMMPRIN (HG-EMMPRIN) that increased after being exposed to inflammatory signals (PMA and H2O2). 2) Glycosylation of EMMPRIN in monocytes/macrophages led to N-linked-glycans being added to the protein, with the HG form containing complex-type glycans and the less-glycosylated form (LG) the simple type. 3) Only the HG-EMMPRIN but not the LG-EMMPRIN exhibited pro-inflammatory effects and stimulated inflammatory activities of the monocytes/macrophages (i.e., activation of ERK1/2 and NF-κB pathway, enhanced monocyte-endothelium adhesion, cell migration and matrix metalloproteinase -9 expression). Post-transcriptional glycosylation represents an important mechanism that determines the biological effects of EMMPRIN in monocytes/macrophages. Glycosylation of EMMPRIN may serve as a potential target for regulating the inflammatory activities of monocytes/macrophages.

Monocyte alterations in rheumatoid arthritis are dominated by preterm release from bone marrow and prominent triggering in the joint.

PubMed

Smiljanovic, Biljana; Radzikowska, Anna; Kuca-Warnawin, Ewa; Kurowska, Weronika; Grün, Joachim R; Stuhlmüller, Bruno; Bonin, Marc; Schulte-Wrede, Ursula; Sörensen, Till; Kyogoku, Chieko; Bruns, Anne; Hermann, Sandra; Ohrndorf, Sarah; Aupperle, Karlfried; Backhaus, Marina; Burmester, Gerd R; Radbruch, Andreas; Grützkau, Andreas; Maslinski, Wlodzimierz; Häupl, Thomas

2018-02-01

Rheumatoid arthritis (RA) accompanies infiltration and activation of monocytes in inflamed joints. We investigated dominant alterations of RA monocytes in bone marrow (BM), blood and inflamed joints. CD14 + cells from BM and peripheral blood (PB) of patients with RA and osteoarthritis (OA) were profiled with GeneChip microarrays. Detailed functional analysis was performed with reference transcriptomes of BM precursors, monocyte blood subsets, monocyte activation and mobilisation. Cytometric profiling determined monocyte subsets of CD14 ++ CD16 - , CD14 ++ CD16 + and CD14 + CD16 + cells in BM, PB and synovial fluid (SF) and ELISAs quantified the release of activation markers into SF and serum. Investigation of genes differentially expressed between RA and OA monocytes with reference transcriptomes revealed gene patterns of early myeloid precursors in RA-BM and late myeloid precursors along with reduced terminal differentiation to CD14 + CD16 + monocytes in RA-PB. Patterns associated with tumor necrosis factor/lipopolysaccharide (TNF/LPS) stimulation were weak and more pronounced in RA-PB than RA-BM. Cytometric phenotyping of cells in BM, blood and SF disclosed differences related to monocyte subsets and confirmed the reduced frequency of terminally differentiated CD14 + CD16 + monocytes in RA-PB. Monocyte activation in SF was characterised by the predominance of CD14 ++ CD16 ++ CD163 + HLA-DR + cells and elevated concentrations of sCD14, sCD163 and S100P. Patterns of less mature and less differentiated RA-BM and RA-PB monocytes suggest increased turnover with accelerated monocytopoiesis, BM egress and migration into inflamed joints. Predominant activation in the joint indicates the action of local and primary stimuli, which may also promote adaptive immune triggering through monocytes, potentially leading to new diagnostic and therapeutic strategies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Enhancement of proinflammatory and procoagulant responses to silica particles by monocyte-endothelial cell interactions

PubMed Central

2012-01-01

Background Inorganic particles, such as drug carriers or contrast agents, are often introduced into the vascular system. Many key components of the in vivo vascular environment include monocyte-endothelial cell interactions, which are important in the initiation of cardiovascular disease. To better understand the effect of particles on vascular function, the present study explored the direct biological effects of particles on human umbilical vein endothelial cells (HUVECs) and monocytes (THP-1 cells). In addition, the integrated effects and possible mechanism of particle-mediated monocyte-endothelial cell interactions were investigated using a coculture model of HUVECs and THP-1 cells. Fe3O4 and SiO2 particles were chosen as the test materials in the present study. Results The cell viability data from an MTS assay showed that exposure to Fe3O4 or SiO2 particles at concentrations of 200 μg/mL and above significantly decreased the cell viability of HUVECs, but no significant loss in viability was observed in the THP-1 cells. TEM images indicated that with the accumulation of SiO2 particles in the cells, the size, structure and morphology of the lysosomes significantly changed in HUVECs, whereas the lysosomes of THP-1 cells were not altered. Our results showed that reactive oxygen species (ROS) generation; the production of interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor (TNF)-α and IL-1β; and the expression of CD106, CD62E and tissue factor in HUVECs and monocytes were significantly enhanced to a greater degree in the SiO2-particle-activated cocultures compared with the individual cell types alone. In contrast, exposure to Fe3O4 particles had no impact on the activation of monocytes or endothelial cells in monoculture or coculture. Moreover, using treatment with the supernatants of SiO2-particle-stimulated monocytes or HUVECs, we found that the enhancement of proinflammatory response by SiO2 particles was not mediated by soluble factors but was dependent on the direct contact between monocytes and HUVECs. Furthermore, flow cytometry analysis showed that SiO2 particles could markedly increase CD40L expression in HUVECs. Our data also demonstrated that the stimulation of cocultures with SiO2 particles strongly enhanced c-Jun NH2-terminal kinase (JNK) phosphorylation and NF-κB activation in both HUVECs and THP-1 cells, whereas the phosphorylation of p38 was not affected. Conclusions Our data demonstrate that SiO2 particles can significantly augment proinflammatory and procoagulant responses through CD40–CD40L-mediated monocyte-endothelial cell interactions via the JNK/NF-κB pathway, which suggests that cooperative interactions between particles, endothelial cells, and monocytes may trigger or exacerbate cardiovascular dysfunction and disease, such as atherosclerosis and thrombosis. These findings also indicate that the monocyte-endothelial cocultures represent a sensitive in vitro model system to assess the potential toxicity of particles and provide useful information that may help guide the future design and use of inorganic particles in biomedical applications. PMID:22985792

Ehrlichia chaffeensis and Its Invasin EtpE Block Reactive Oxygen Species Generation by Macrophages in a DNase X-Dependent Manner.

PubMed

Teymournejad, Omid; Lin, Mingqun; Rikihisa, Yasuko

2017-11-21

The obligatory intracellular pathogen Ehrlichia chaffeensis lacks most genes that confer resistance to oxidative stress but can block reactive oxygen species (ROS) generation by host monocytes-macrophages. Bacterial and host molecules responsible for this inhibition have not been identified. To infect host cells, Ehrlichia uses the C terminus of its surface invasin, entry-triggering protein of Ehrlichia (EtpE; EtpE-C), which directly binds the mammalian cell surface receptor glycosylphosphatidylinositol-anchored protein DNase X. We investigated whether EtpE-C binding to DNase X blocks ROS production by mouse bone marrow-derived macrophages (BMDMs). On the basis of a luminol-dependent chemiluminescence assay, E. chaffeensis inhibited phorbol myristate acetate (PMA)-induced ROS generation by BMDMs from wild-type, but not DNase X -/- , mice. EtpE-C is critical for inhibition, as recombinant EtpE-C (rEtpE-C)-coated latex beads, but not recombinant N-terminal EtpE-coated or uncoated beads, inhibited PMA-induced ROS generation by BMDMs from wild-type mice. DNase X is required for this inhibition, as none of these beads inhibited PMA-induced ROS generation by BMDMs from DNase X -/- mice. Previous studies showed that E. chaffeensis does not block ROS generation in neutrophils, a cell type that is a potent ROS generator but is not infected by E. chaffeensis Human and mouse peripheral blood neutrophils did not express DNase X. Our findings point to a unique survival mechanism of ROS-sensitive obligate intramonocytic bacteria that involves invasin EtpE binding to DNase X on the host cell surface. This is the first report of bacterial invasin having such a subversive activity on ROS generation. IMPORTANCE Ehrlichia chaffeensis preferentially infects monocytes-macrophages and causes a life-threatening emerging tick-transmitted infectious disease called human monocytic ehrlichiosis. Ehrlichial infection, and hence the disease, depends on the ability of this bacterium to avoid or overcome powerful microbicidal mechanisms of host monocytes-macrophages, one of which is the generation of ROS. Our findings reveal that an ehrlichial surface invasin, EtpE, not only triggers bacterial entry but also blocks ROS generation by host macrophages through its host cell receptor, DNase X. As ROS sensitivity is an Achilles' heel of this group of pathogens, understanding the mechanism by which E. chaffeensis rapidly blocks ROS generation suggests a new approach for developing effective anti-infective measures. The discovery of a ROS-blocking pathway is also important, as modulation of ROS generation is important in a variety of ailments and biological processes. Copyright © 2017 Teymournejad et al.

Brief Report: CD14brightCD16- monocytes and sCD14 level negatively associate with CD4-memory T-cell frequency and predict HCV-decline on therapy.

PubMed

Judge, Chelsey J; Sandberg, Johan K; Funderburg, Nicholas T; Sherman, Kenneth E; Butt, Adeel A; Kang, Minhee; Landay, Alan L; Lederman, Michael M; Anthony, Donald D

2016-11-01

During HIV+ hepatitis C virus (HCV)+ coinfection CD14CD16 monocytes produce soluble immune-activation markers that predict disease progression and poor response to interferon (IFN)-α treatment. We evaluated relationships among immune activation, monocyte phenotype, CD4-memory T cells, and HCV-, cytomegalovirus-, and cytomegalovirus/Epstein-Barr virus/influenza-specific IFN-γ-response before and during IFN-α treatment. Effector-memory and central-memory CD4 T-cell frequencies were lower in HCV+ HIV+ donors than in uninfected donors and correlated negatively with HCV level, CD14CD16 monocytes, and plasma sCD14. sCD14 and CD14CD16 monocytes negatively correlated with IFN-α-dependent HCV decline. CD4 effector-memory T cells positively associated with cytomegalovirus/Epstein-Barr virus/influenza(CEF)-specific IFN-γ response, while sCD14 negatively associated with both CD4 effector-memory T cells and CEF-specific IFN-γ response. These data support a role for memory-CD4 T cells in HCV containment and link immune activation and CD14CD16-monocyte frequency to the failure of IFN-dependent HCV clearance.

Activation of coagulation by a thalidomide-based regimen.

PubMed

Hoshi, Asuka; Matsumoto, Aya; Chung, Jihwa; Isozumi, Yu; Koyama, Takatoshi

2011-09-01

Combining thalidomide (Thal) with chemotherapeutic agents or steroid preparations led to improved response rates in the treatment of multiple myeloma. However, deep vein thrombosis (DVT) is one of the most serious side-effects noted with this regimen, and how a Thal-based regimen causes DVT is unclear. We investigated the procoagulant effects of Thal when combined with chemotherapeutic agents in vitro, focusing on tissue factor (TF) and phosphatidylserine. We examined the effects of the chemotherapeutic doxorubicin hydrochloride (Dox) and the steroid dexamethasone (Dex), with or without Thal. Our study used the human vascular endothelial, monocytic, and myeloma cell lines, EAhy926, THP-1, and RPMI8226, respectively. In EAhy926 and THP-1, Dex treatment increased expression of TF, which may induce procoagulant activity (PCA). Upregulation of TF mRNA correlated with activation of the Egr-1 pathway. In Thal and Dex treatments, the increase of PCA induction from phosphatidylserine exposure was modest. In contrast, Dox and Thal-Dox increased phosphatidylserine exposure in both cell types. In THP-1 cells, cell surface phosphatidylserine exposure correlated with increased PCA by Dox. Thal alone showed a modest increase in phosphatidylserine exposure in endothelial cells and monocytes. When Thal is given in combination with chemotherapies or Dex, endothelial cell and monocyte PCA may be induced through phosphatidylserine exposure, or TF expression. Induction may be protracted by Thal, which has an antiangiogenic activity. Therefore, prophylactic anticoagulant strategies should be considered in Thal-based combination regimens.

Human monoclonal antibodies reactive with human myelomonocytic leukemia cells.

PubMed

Posner, M R; Santos, D J; Elboim, H S; Tumber, M B; Frackelton, A R

1989-04-01

Peripheral blood mononuclear cells from a patient with chronic myelogenous leukemia (CML), in remission, were depleted of CD8-positive T-cells and cultured with Epstein-Barr virus. Four of 20 cultures (20%) secreted human IgG antibodies selectively reactive with the cell surfaces of certain human leukemia cell lines. Three polyclonal, Epstein-Barr virus-transformed, B-cell lines were expanded and fused with the human-mouse myeloma analogue HMMA2.11TG/O. Antibody from secreting clones HL 1.2 (IgG1), HL 2.1 (IgG3), and HL 3.1 (IgG1) have been characterized. All three react with HL-60 (promyelocytic), RWLeu4 (CML promyelocytic), and U937 (monocytic), but not with KG-1 (myeloblastic) or K562 (CML erythroid). There is no reactivity with T-cell lines, Burkitt's cell lines, pre-B-leukemia cell lines, or an undifferentiated CML cell line, BV173. Leukemic cells from two of seven patients with acute myelogenous leukemia and one of five with acute lymphocytic leukemia react with all three antibodies. Normal lymphocytes, monocytes, polymorphonuclear cells, red blood cells, bone marrow cells, and platelets do not react. Samples from patients with other diverse hematopoietic malignancies showed no reactivity. Immunoprecipitations suggest that the reactive antigen(s) is a lactoperoxidase iodinatable series of cell surface proteins with molecular weights of 42,000-54,000 and a noniodinatable protein with a molecular weight of 82,000. Based on these data these human monoclonal antibodies appear to react with myelomonocytic leukemic cells and may detect a leukemia-specific antigen or a highly restricted differentiation antigen.

Increased monocytes and bands following a red blood cell transfusion.

PubMed

Ellefson, A M; Locke, R G; Zhao, Y; Mackley, A B; Paul, D A

2016-01-01

The objective of this study is to analyze the white blood cell changes that occur after a transfusion of red blood cells in order to identify a subclinical inflammatory response in neonates. Retrospective analysis of infants who received a red blood cell transfusion in an intensive care nursery. White blood cell results within 24 h pre- to 48 h post-transfusion were collected and analyzed. Statistical analysis included ANOVA, T-test, Mann-Whitney U test, Pearson's correlation and multivariable linear regression. Monocytes (P=0.02) and bands (P=0.035) were increased post-transfusion. There were no differences in monocytes (P=0.46) or bands (P=0.56) between groups who did or did not have blood cultures obtained. There was no difference in monocytes between groups who did or did not have sepsis (P=0.88). We identified an elevation in monocytes and bands in the 48 h following a transfusion in premature infants. Our findings support a possible pro-inflammatory response related to transfusion of red blood cells.

Phylogeny of lymphocyte heterogeneity: the cellular requirements for the mixed leucocyte reaction with channel catfish.

PubMed Central

Miller, N W; Deuter, A; Clem, L W

1986-01-01

Vigorous mixed leucocyte reactions (MLR) were obtained using channel catfish peripheral blood leucocytes (PBL) when equal numbers of responder and stimulator cells (5 X 10(5) cells each) were cocultured. The use of 2000 rads of X-irradiation was sufficient to block subsequent proliferative responses of the stimulator cells. The cellular requirements for channel catfish MLR responses were assessed by using three functionally distinct leucocyte subpopulations isolated from the PBL. B cells (sIg+ lymphocytes) and T cells (sIg- lymphocytes) were isolated by an indirect panning procedure employing a monoclonal antibody specific for channel catfish Ig. A third population, monocytes, was isolated or depleted by adherence to baby hamster kidney cell microexudate-coated surfaces or adherence to Sephadex G-10, respectively. The results indicated that only the T cells were able to respond in the fish MLR, with monocytes being required as accessory cells. In contrast, all three cell types could function as stimulator cells. In addition, it was observed that low in vitro culture temperatures inhibited the generation of channel catfish MLRs, thereby supporting the contention that low temperature immunosuppression in fish results from a preferential inhibition of the generation of primary T-cell responses. PMID:2944817

Cosmos 2229 immunology study (Experiment K-8-07)

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald

1993-01-01

The purpose of the current study was to further validate use of the rhesus monkey as a model for humans in future space flight testing. The areas of immunological importance examined in the Cosmos 2229 flight were represented by two sets of studies. The first set of studies determined the effect of space flight on the ability of bone marrow cells to respond to granulocyte/monocyte colony stimulating factor (GM-CSF). GM-CSF is an important regulator in the differentiation of bone marrow cells of both monocyte/macrophage and granulocyte lineages and any change in the ability of these cells to respond to GM-CSF can result in altered immune function. A second set of studies determined space flight effects on the expression of cell surface markers on both spleen and bone marrow cells. Immune cell markers included in this study were those for T-cell, B-cell, natural killer cell, and interleukin-2 populations. Variations from a normal cell population percentage, as represented by these markers, can be correlated with alterations in immunological function. Cells were stained with fluorescein-labelled antibodies directed against the appropriate antigens, and then analyzed using a flow cytometer.

Protein synthesis of the pro-inflammatory S100A8/A9 complex in plasmacytoid dendritic cells and cell surface S100A8/A9 on leukocyte subpopulations in systemic lupus erythematosus

PubMed Central

2011-01-01

Introduction Systemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in many different organ systems, activation of leukocytes and production of pro-inflammatory cytokines. The heterodimer of the cytosolic calcium-binding proteins S100A8 and S100A9 (S100A8/A9) is secreted by activated polymorphonuclear neutrophils (PMNs) and monocytes and serves as a serum marker for several inflammatory diseases. Furthermore, S100A8 and S100A9 have many pro-inflammatory properties such as binding to Toll-like receptor 4 (TLR4). In this study we investigated if aberrant cell surface S100A8/A9 could be seen in SLE and if plasmacytoid dendritic cells (pDCs) could synthesize S100A8/A9. Methods Flow cytometry, confocal microscopy and real-time PCR of flow cytometry-sorted cells were used to measure cell surface S100A8/A9, intracellular S100A8/A9 and mRNA levels of S100A8 and S100A9, respectively. Results Cell surface S100A8/A9 was detected on all leukocyte subpopulations investigated except for T cells. By confocal microscopy, real-time PCR and stimulation assays, we could demonstrate that pDCs, monocytes and PMNs could synthesize S100A8/A9. Furthermore, pDC cell surface S100A8/A9 was higher in patients with active disease as compared to patients with inactive disease. Upon immune complex stimulation, pDCs up-regulated the cell surface S100A8/A9. SLE patients had also increased serum levels of S100A8/A9. Conclusions Patients with SLE had increased cell surface S100A8/A9, which could be important in amplification and persistence of inflammation. Importantly, pDCs were able to synthesize S100A8/A9 proteins and up-regulate the cell surface expression upon immune complex-stimulation. Thus, S100A8/A9 may be a potent target for treatment of inflammatory diseases such as SLE. PMID:21492422

Fibronectin-mediation cell adhesion is required for induction of 92-kDa type IV collagenase/gelatinase (MMP-9) gene expression during macrophage differentiation : the signaling role of protein kinase C-{beta}.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, B.; Laouar, A.; Huberman, E.

1998-05-08

Induction of the 92-kDa gelatinase (MMP-9) gene expression is associated with macrophage differentiation. In this study, we explored the regulatory mechanisms underlying this differentiation-associated MMP-9 gene expression in human HL-60 myeloid leukemia cells and human peripheral blood monocytes. Phorbol 12-myristate 13-acetate (PMA) markedly induced MMP-9 gene expression in HL-60 cells; the induction closely paralleled the timing and extent of PMA-induced cell adhesion and spreading, a hallmark of macrophage differentiation. Similarly, treatment with PMA or macrophage-colony stimulating factor stimulated adherence and spreading of blood monocytes with a concurrent 7- or 5-fold increase in MMP-9 production, respectively. In protein kinase C (PKC)-betamore » -deficient HL-60 variant cells (HL-525), PMA failed to induce cell adhesion and MMP-9 gene expression. Transfecting HL-525 cells with a PKC-beta expression plasmid restored PKC-beta levels and PMA inducibility of cell adhesion and spreading as well as MMP-9 gene expression. Induction of cell adhesion and MMP-9 gene expression in HL-60 cells and blood monocytes was strongly inhibited by neutralizing monoclonal antibodies to fibronectin (FN) and its receptor {alpha}5{beta}1 integrin. HL-525 cells, which constitutively display high levels of surface {alpha}5{beta}1 integrin, adhered and spread on immobilized FN with concomitant induction of MMP-9 gene expression. Cytochalasins B and D were each a potent inhibitor of MMP-9 production. Our results suggest that {alpha}5{beta}1 integrin-mediated interaction of immature hematopoietic cells with FN plays a critical role in modulating matrix-degrading activities during macrophage differentiation.« less

Mitogenic signal transduction in T lymphocytes in microgravity

NASA Technical Reports Server (NTRS)

Cogoli, A.; Bechler, B.; Cogoli-Greuter, M.; Criswell, S. B.; Joller, H.; Joller, P.; Hunzinger, E.; Muller, O.

1993-01-01

The activation by concanavalin A Con A of human peripheral blood lymphocytes (PBLs) in the presence of monocytes as accessory cells was investigated in cultures exposed to microgravity conditions in Spacelab. Activation of T cells was measured as incorporation of [3H]thymidine into DNA, secretion of interleukin-2 (IL-2), and interferon-gamma, and expression of IL-2 receptors. Whereas, as discovered in earlier experiments, the activation of resuspended T cells is strongly inhibited, activation of cells attached to microcarrier beads is more than doubled in microgravity. The results suggest that the depression of the activation in resuspended cells may be attributed to a malfunction of monocytes acting as accessory cells. In fact, although the ultrastructure of resuspended monocytes is not altered in microgravity, the secretion of IL-1 is strongly inhibited. Our data suggest that (1) IL-2 is produced independently of IL-1, (2) IL-1 production is triggered only when monocytes (and lymphocytes?) adhere to microcarriers, (3) the expression of IL-2 receptors depends on IL-1, and (4) provided sufficient IL-1 is available, activation is enhanced in microgravity. Finally, cultures of resuspended PBLs and monocytes in microgravity constitute a complete and natural system in which monocytes are not operational. This may be useful for studies of the role of accessory cells and cell-cell interactions in T lymphocyte activation.

Differential infection outcome of Chlamydia trachomatis in human blood monocytes and monocyte-derived dendritic cells

PubMed Central

2014-01-01

Background Chlamydia trachomatis is an intracellular bacteria which consist of three biovariants; trachoma (serovars A-C), urogenital (serovars D-K) and lymphogranuloma venereum (L1-L3), causing a wide spectrum of disease in humans. Monocytes are considered to disseminate this pathogen throughout the body while dendritic cells (DCs) play an important role in mediating immune response against bacterial infection. To determine the fate of C. trachomatis within human peripheral blood monocytes and monocyte-derived DCs, these two sets of immune cells were infected with serovars Ba, D and L2, representative of the three biovariants of C. trachomatis. Results Our study revealed that the different serovars primarily infect monocytes and DCs in a comparable fashion, however undergo differential infection outcome, serovar L2 being the only candidate to inflict active infection. Moreover, the C. trachomatis serovars Ba and D become persistent in monocytes while the serovars predominantly suffer degradation within DCs. Effects of persistence gene Indoleamine 2, 3-dioxygenase (IDO) was not clearly evident in the differential infection outcome. The heightened levels of inflammatory cytokines secreted by the chlamydial infection in DCs compared to monocytes seemed to be instrumental for this consequence. The immune genes induced in monocytes and DCs against chlamydial infection involves a different set of Toll-like receptors, indicating that distinct intracellular signalling pathways are adopted for immune response. Conclusion Our results demonstrate that the host pathogen interaction in chlamydia infection is not only serovar specific but manifests cell specific features, inducing separate immune response cascade in monocytes and DCs. PMID:25123797

Immune cell phenotype and function in sepsis

PubMed Central

Rimmelé, Thomas; Payen, Didier; Cantaluppi, Vincenzo; Marshall, John; Gomez, Hernando; Gomez, Alonso; Murray, Patrick; Kellum, John A.

2015-01-01

Cells of the innate and adaptive immune systems play a critical role in the host response to sepsis. Moreover, their accessibility for sampling and their capacity to respond dynamically to an acute threat increases the possibility that leukocytes might serve as a measure of a systemic state of altered responsiveness in sepsis. The working group of the 14th Acute Dialysis Quality Initiative (ADQI) conference sought to obtain consensus on the characteristic functional and phenotypic changes in cells of the innate and adaptive immune system in the setting of sepsis. Techniques for the study of circulating leukocytes were also reviewed and the impact on cellular phenotypes and leukocyte function of non extracorporeal treatments and extracorporeal blood purification therapies proposed for sepsis was analyzed. A large number of alterations in the expression of distinct neutrophil and monocyte surface markers have been reported in septic patients. The most consistent alteration seen in septic neutrophils is their activation of a survival program that resists apoptotic death. Reduced expression of HLA-DR is a characteristic finding on septic monocytes but monocyte antimicrobial function does not appear to be significantly altered in sepsis. Regarding adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and it involves all types of T cells (CD4, CD8 and Natural Killer) except T regulatory cells, thus favoring immunosuppression. Finally, numerous promising therapies targeting the host immune response to sepsis are under investigation. These potential treatments can have an effect on the number of immune cells, the proportion of cell subtypes and the cell function. PMID:26529661

IMMUNE CELL PHENOTYPE AND FUNCTION IN SEPSIS.

PubMed

Rimmelé, Thomas; Payen, Didier; Cantaluppi, Vincenzo; Marshall, John; Gomez, Hernando; Gomez, Alonso; Murray, Patrick; Kellum, John A

2016-03-01

Cells of the innate and adaptive immune systems play a critical role in the host response to sepsis. Moreover, their accessibility for sampling and their capacity to respond dynamically to an acute threat increases the possibility that leukocytes might serve as a measure of a systemic state of altered responsiveness in sepsis.The working group of the 14th Acute Dialysis Quality Initiative (ADQI) conference sought to obtain consensus on the characteristic functional and phenotypic changes in cells of the innate and adaptive immune system in the setting of sepsis. Techniques for the study of circulating leukocytes were also reviewed and the impact on cellular phenotypes and leukocyte function of nonextracorporeal treatments and extracorporeal blood purification therapies proposed for sepsis was analyzed.A large number of alterations in the expression of distinct neutrophil and monocyte surface markers have been reported in septic patients. The most consistent alteration seen in septic neutrophils is their activation of a survival program that resists apoptotic death. Reduced expression of HLA-DR is a characteristic finding on septic monocytes, but monocyte antimicrobial function does not appear to be significantly altered in sepsis. Regarding adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and it involves all types of T cells (CD4, CD8, and Natural Killer) except T regulatory cells, thus favoring immunosuppression. Finally, numerous promising therapies targeting the host immune response to sepsis are under investigation. These potential treatments can have an effect on the number of immune cells, the proportion of cell subtypes, and the cell function.

CXCL4-induced macrophages in human atherosclerosis.

PubMed

Domschke, Gabriele; Gleissner, Christian A

2017-09-09

Atherosclerosis is considered an inflammatory disease of the arterial wall. Monocytes and monocyte-derived cells (most often termed macrophages) play an essential role in the formation of atherosclerotic lesions, as they take up lipids leading to subsequent foam cell formation accompanied by release of pro-inflammatory cytokines. Similarly, platelets have been discovered to represent an important cell type mediating inflammatory and immune processes in atherogenesis, mainly by secreting chemokines, which are stored in the platelets' alpha granules, upon platelet activation. Therefore, the interaction between monocyte-derived cells and platelets is of exceptional importance. In this review, we specifically focus on the chemokine (platelet factor-4, PF4) and its effects on monocytes and monocyte-derived cells. By formation of heterodimers dimers and -oligomers with CCL5, CXCL4 induces binding of monocytes cells to endothelial cell and thereby promotes diapedesis of monocytes into the subendothelial space. CXCL4 also affects the differentiation of monocytes as it induces a specific macrophage phenotype, which we suggested to term "M4". For example, CXCL4-induced macrophages irreversibly lose the hemoglobin-haptoglobin scavenger receptor CD163. The combination of CD68, S100A8, and MMP7 turned out to reliably identify M4 macrophages both in vitro and in vivo within atherosclerotic lesions. In human atherosclerotic plaques, M4 macrophages are predominantly present in the adventitia and the intima and their prevalence is associated with plaque instability suggesting that they are a marker of pro-inflammatory activity. Overall, CXCL4-induced M4 macrophages may represent a target for diagnostic and therapeutic interventions in human atherosclerotic disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Zoledronic acid modulates maturation of human monocyte-derived dendritic cells.

PubMed

Orsini, Giulia; Failli, Alessandra; Legitimo, Annalisa; Adinolfi, Barbara; Romanini, Antonella; Consolini, Rita

2011-12-01

Zoledronic acid (ZA) is a drug of the bisphosphonate class, which is widely used for the treatment of both osteoporosis and skeletal metastasis. Besides its main bone antiresorptive activity, ZA displays antitumor properties, by triggering the expansion and activation of γδ T-cells, which exert an antitumor effect through dendritic cells (DCs). Several studies have reported the interaction between ZA and γδ T-cells, but the potential immunoregulatory activity of this drug on DCs has scarcely been investigated. Therefore, in this paper, we evaluated the effects of a therapeutic dose of ZA on the in vitro generation and maturation of DCs derived from peripheral blood monocytes of healthy adult donors. We demonstrate that ZA treatment did not affect DC differentiation, but inhibited DC maturation on lipopolysaccharide activation, as shown by the impaired expression of maturation surface markers and reduced ability to induce allogeneic T-cell proliferation. Interestingly, IL-10 secretion by mature DCs was significantly lower in ZA-treated cells than in controls. We conclude that ZA exerts its immunological in vitro activity also by modulating the maturation of DCs.

Counter-flow elutriation of clinical peripheral blood mononuclear cell concentrates for the production of dendritic and T cell therapies.

PubMed

Stroncek, David F; Fellowes, Vicki; Pham, Chauha; Khuu, Hanh; Fowler, Daniel H; Wood, Lauren V; Sabatino, Marianna

2014-09-17

Peripheral blood mononuclear cells (PBMC) concentrates collected by apheresis are frequently used as starting material for cellular therapies, but the cell of interest must often be isolated prior to initiating manufacturing. The results of enriching 59 clinical PBMC concentrates for monocytes or lymphocytes from patients with solid tumors or multiple myeloma using a commercial closed system semi-automated counter-flow elutriation instrument (Elutra, Terumo BCT) were evaluated for quality and consistency. Elutriated monocytes (n = 35) were used to manufacture autologous dendritic cells and elutriated lymphocytes (n = 24) were used manufacture autologous T cell therapies. Elutriated monocytes with >10% neutrophils were subjected to density gradient sedimentation to reduce neutrophil contamination and elutriated lymphocytes to RBC lysis. Elutriation separated the PBMC concentrates into 5 fractions. Almost all of the lymphocytes, platelets and red cells were found in fractions 1 and 2; in contrast, most of the monocytes, 88.6 ± 43.0%, and neutrophils, 74.8 ± 64.3%, were in fraction 5. In addition, elutriation of 6 PBMCs resulted in relatively large quantities of monocytes in fractions 1 or 2. These 6 PBMCs contained greater quantities of monocytes than the other 53 PBMCs. Among fraction 5 isolates 38 of 59 contained >10% neutrophils. High neutrophil content of fraction 5 was associated with greater quantities of neutrophils in the PBMC concentrate. Following density gradient separation the neutrophil counts fell to 3.6 ± 3.4% (all products contained <10% neutrophils). Following red cell lysis of the elutriated lymphocyte fraction the lymphocyte recovery was 86.7 ± 24.0% and 34.3 ± 37.4% of red blood cells remained. Elutriation was consistent and effective for isolating monocytes and lymphocytes from PBMC concentrates for manufacturing clinical cell therapies, but further processing is often required.

Whole Blood Activation Results in Altered T Cell and Monocyte Cytokine Production Profiles by Flow Cytometry

NASA Technical Reports Server (NTRS)

Crucian, Brian E.; Sams, Clarence F.

2001-01-01

An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry, a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a whole-blood activation culture has been described. In this study, whole blood activation was compared to traditional PBMC activation and the individual cytokine secretion patterns for both T cells, T cell subsets and monocytes was determined by flow cytometry. RESULTS: For T cell cytokine assessment (IFNg/IL-10 and IL-21/L-4) following PMA +ionomycin activation: (1) a Significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture and (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. Four-color analysiS was used to allow assessment of cytokine production by specific T cell subsets. It was found that IFNgamma production was significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were Significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines (IL-1a/IL-12 and TNFa/IL-10) in conjunction with CD14. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFa. equally well in both culture systems, however monocyte production of IL-10 was significantly elevated in whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing monocytes may represent distinct monocyte subsets with unique functions. CONCLUSIONS: Whole blood culture eliminates the need to purify cell populations prior to culture and may have Significant utility for the routine monitoring of the cytokine balances of the peripheral blood T cell and monocyte populations. In addition, there are distinct advantages to performing whole-blood (WB) activation as compared to PBMC activation. These advantages would include retaining all various cell-cell interactions as well as any soluble factors present in serum that influence cell activation. In this study, alterations in cytokine production are demonstrated between whole blood and PBMC activation. It is likely that whole blood activation more accurately represents the in-vivo immune balance than PBMC activation.

Aberrant glycosylation of plasma proteins in severe preeclampsia promotes monocyte adhesion.

PubMed

Flood-Nichols, Shannon K; Kazanjian, Avedis A; Tinnemore, Deborah; Gafken, Philip R; Ogata, Yuko; Napolitano, Peter G; Stallings, Jonathan D; Ippolito, Danielle L

2014-02-01

Glycosylation of plasma proteins increases during pregnancy. Our objectives were to investigate an anti-inflammatory role of these proteins in normal pregnancies and determine whether aberrant protein glycosylation promotes monocyte adhesion in preeclampsia. Plasma was prospectively collected from nonpregnant controls and nulliparous patients in all 3 trimesters. Patients were divided into cohorts based on the applicable postpartum diagnosis. U937 monocytes were preconditioned with enzymatically deglycosylated plasma, and monocyte adhesion to endothelial cell monolayers was quantified by spectrophotometry. Plasma from nonpregnant controls, first trimester normotensives, and first trimester patients with mild preeclampsia inhibited monocyte-endothelial cell adhesion (P < .05), but plasma from first trimester patients with severe preeclampsia and second and third trimester normotensives did not. Deglycosylating plasma proteins significantly increased adhesion in all the cohorts. These results support a role of plasma glycoprotein interaction in monocyte-endothelial cell adhesion and could suggest a novel therapeutic target for severe preeclampsia.

Systemic T Cells Immunosuppression of Glioma Stem Cell-Derived Exosomes Is Mediated by Monocytic Myeloid-Derived Suppressor Cells

PubMed Central

Domenis, Rossana; Cesselli, Daniela; Toffoletto, Barbara; Bourkoula, Evgenia; Caponnetto, Federica; Manini, Ivana; Beltrami, Antonio Paolo; Ius, Tamara; Skrap, Miran; Di Loreto, Carla

2017-01-01

A major contributing factor to glioma development and progression is its ability to evade the immune system. Nano-meter sized vesicles, exosomes, secreted by glioma-stem cells (GSC) can act as mediators of intercellular communication to promote tumor immune escape. Here, we investigated the immunomodulatory properties of GCS-derived exosomes on different peripheral immune cell populations. Healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3, anti-CD28 and IL-2, were treated with GSC-derived exosomes. Phenotypic characterization, cell proliferation, Th1/Th2 cytokine secretion and intracellular cytokine production were analysed by distinguishing among effector T cells, regulatory T cells and monocytes. In unfractionated PBMCs, GSC-derived exosomes inhibited T cell activation (CD25 and CD69 expression), proliferation and Th1 cytokine production, and did not affect cell viability or regulatory T-cell suppression ability. Furthermore, exosomes were able to enhance proliferation of purified CD4+ T cells. In PBMCs culture, glioma-derived exosomes directly promoted IL-10 and arginase-1 production and downregulation of HLA-DR by unstimulated CD14+ monocytic cells, that displayed an immunophenotype resembling that of monocytic myeloid-derived suppressor cells (Mo-MDSCs). Importantly, the removal of CD14+ monocytic cell fraction from PBMCs restored T-cell proliferation. The same results were observed with exosomes purified from plasma of glioblastoma patients. Our results indicate that glioma-derived exosomes suppress T-cell immune response by acting on monocyte maturation rather than on direct interaction with T cells. Selective targeting of Mo-MDSC to treat glioma should be considered with regard to how immune cells allow the acquirement of effector functions and therefore counteracting tumor progression. PMID:28107450

Systemic T Cells Immunosuppression of Glioma Stem Cell-Derived Exosomes Is Mediated by Monocytic Myeloid-Derived Suppressor Cells.

PubMed

Domenis, Rossana; Cesselli, Daniela; Toffoletto, Barbara; Bourkoula, Evgenia; Caponnetto, Federica; Manini, Ivana; Beltrami, Antonio Paolo; Ius, Tamara; Skrap, Miran; Di Loreto, Carla; Gri, Giorgia

2017-01-01

A major contributing factor to glioma development and progression is its ability to evade the immune system. Nano-meter sized vesicles, exosomes, secreted by glioma-stem cells (GSC) can act as mediators of intercellular communication to promote tumor immune escape. Here, we investigated the immunomodulatory properties of GCS-derived exosomes on different peripheral immune cell populations. Healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3, anti-CD28 and IL-2, were treated with GSC-derived exosomes. Phenotypic characterization, cell proliferation, Th1/Th2 cytokine secretion and intracellular cytokine production were analysed by distinguishing among effector T cells, regulatory T cells and monocytes. In unfractionated PBMCs, GSC-derived exosomes inhibited T cell activation (CD25 and CD69 expression), proliferation and Th1 cytokine production, and did not affect cell viability or regulatory T-cell suppression ability. Furthermore, exosomes were able to enhance proliferation of purified CD4+ T cells. In PBMCs culture, glioma-derived exosomes directly promoted IL-10 and arginase-1 production and downregulation of HLA-DR by unstimulated CD14+ monocytic cells, that displayed an immunophenotype resembling that of monocytic myeloid-derived suppressor cells (Mo-MDSCs). Importantly, the removal of CD14+ monocytic cell fraction from PBMCs restored T-cell proliferation. The same results were observed with exosomes purified from plasma of glioblastoma patients. Our results indicate that glioma-derived exosomes suppress T-cell immune response by acting on monocyte maturation rather than on direct interaction with T cells. Selective targeting of Mo-MDSC to treat glioma should be considered with regard to how immune cells allow the acquirement of effector functions and therefore counteracting tumor progression.

Immune cell activation and cytokine release after stimulation of whole blood with pneumococcal C-polysaccharide and capsular polysaccharides.

PubMed

Sundberg-Kövamees, Marianne; Grunewald, Johan; Wahlström, Jan

2016-11-01

Streptococcus pneumonia is a major cause of morbidity and mortality in children and adults worldwide. Lack of fully effective pneumococcal vaccines is a problem. Streptococcus pneumoniae exposes on its surface C-polysaccharide (cell wall polysaccharide, CWPS) and serospecific capsular polysaccharides, used in pneumococcal vaccines. We investigated the effect of CWPS and individual capsular polysaccharides, with regard to activation of subsets of immune cells of healthy controls. Three different capsular polysaccharides, CWPS and LPS were used for in vitro stimulation of whole blood. Cell activation (CD69 expression) was assessed in CD4+ and CD4- T cells, NK-like T cells, NK cells and monocytes by flow cytometry. Cytokine levels in supernatants were quantified by Cytometric Bead Array (CBA). CWPS and the capsules activated immune cell subsets, but to different degrees. NK cells and NK-like T cells showed the strongest activation, followed by monocytes. Among the three capsules, capsule type 23 induced the strongest activation and cytokine release, followed by type 9 and type 3. This study increases the understanding of how the human immune system reacts to pneumococcal vaccine components. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Both Cerebral and Hematopoietic Deficiencies in CCR2 Result in Uncontrolled Herpes Simplex Virus Infection of the Central Nervous System in Mice.

PubMed

Menasria, Rafik; Canivet, Coraline; Piret, Jocelyne; Gosselin, Jean; Boivin, Guy

2016-01-01

CCR2 is a chemokine receptor expressed on the surface of blood leukocytes, particularly «Ly6Chi» inflammatory monocytes and microglia. Signaling through this receptor is thought to influence the immune activity of microglia as well as monocytes egress from the bone marrow (BM) and their trafficking into the central nervous system (CNS) in several neurological diseases. During experimental herpes simplex virus 1 (HSV-1) encephalitis (HSE), CCR2 deficiency has been reported to exacerbate the outcome of the disease. However, the precise contribution of CCR2 expressed in cells of the CNS or peripheral monocytes in the protection against HSE remains unclear. To dissect the differential role of CCR2 during HSE, chimeric mice with receptor deficiency in the brain or blood cells were generated by transplanting wild-type (WT) C57BL/6 or CCR2-/- BM-derived cells in CCR2-/- (WT→CCR2-/-) and WT (CCR2-/-→WT) mice, respectively. Our results indicate that following intranasal infection with 1.2x106 plaque forming units of HSV-1, CCR2 deficiency in hematopoietic cells and, to a lesser extent, in CNS exacerbates the outcome of HSE. Mortality rates of CCR2-/- (71.4%) and CCR2-/-→WT (57.1%) mice were significantly higher than that of WT (15.3%; P<0.01 and P<0.05, respectively) but the difference did not reach statistical significance for WT→CCR2-/- animals (42.8%; P = 0.16). Both peripheral and CNS deficiencies in CCR2 resulted in increased infectious viral titers and wider dissemination of HSV antigens in the brain as well as an overproduction of inflammatory cytokines and chemokines including IL-1β, IL-6, CCL2, CCL3 and CCL5. Furthermore, CCR2 deficiency in the hematopoietic system altered monocytes egress from the BM and their recruitment to the CNS, which may contribute to the failure in HSV-1 containment. Collectively, these data suggest that CCR2 expressed on cells of CNS and especially on peripheral monocytes is important for the control of HSV-1 replication and inflammatory environment during experimental HSE.

Both Cerebral and Hematopoietic Deficiencies in CCR2 Result in Uncontrolled Herpes Simplex Virus Infection of the Central Nervous System in Mice

PubMed Central

Menasria, Rafik; Canivet, Coraline; Piret, Jocelyne; Gosselin, Jean; Boivin, Guy

2016-01-01

CCR2 is a chemokine receptor expressed on the surface of blood leukocytes, particularly «Ly6Chi» inflammatory monocytes and microglia. Signaling through this receptor is thought to influence the immune activity of microglia as well as monocytes egress from the bone marrow (BM) and their trafficking into the central nervous system (CNS) in several neurological diseases. During experimental herpes simplex virus 1 (HSV-1) encephalitis (HSE), CCR2 deficiency has been reported to exacerbate the outcome of the disease. However, the precise contribution of CCR2 expressed in cells of the CNS or peripheral monocytes in the protection against HSE remains unclear. To dissect the differential role of CCR2 during HSE, chimeric mice with receptor deficiency in the brain or blood cells were generated by transplanting wild-type (WT) C57BL/6 or CCR2-/- BM-derived cells in CCR2-/- (WT→CCR2-/-) and WT (CCR2-/-→WT) mice, respectively. Our results indicate that following intranasal infection with 1.2x106 plaque forming units of HSV-1, CCR2 deficiency in hematopoietic cells and, to a lesser extent, in CNS exacerbates the outcome of HSE. Mortality rates of CCR2-/- (71.4%) and CCR2-/-→WT (57.1%) mice were significantly higher than that of WT (15.3%; P<0.01 and P<0.05, respectively) but the difference did not reach statistical significance for WT→CCR2-/- animals (42.8%; P = 0.16). Both peripheral and CNS deficiencies in CCR2 resulted in increased infectious viral titers and wider dissemination of HSV antigens in the brain as well as an overproduction of inflammatory cytokines and chemokines including IL-1β, IL-6, CCL2, CCL3 and CCL5. Furthermore, CCR2 deficiency in the hematopoietic system altered monocytes egress from the BM and their recruitment to the CNS, which may contribute to the failure in HSV-1 containment. Collectively, these data suggest that CCR2 expressed on cells of CNS and especially on peripheral monocytes is important for the control of HSV-1 replication and inflammatory environment during experimental HSE. PMID:27930721

Lipid emulsions differentially affect LPS-induced acute monocytes inflammation: in vitro effects on membrane remodeling and cell viability.

PubMed

Boisramé-Helms, Julie; Delabranche, Xavier; Klymchenko, Andrey; Drai, Jocelyne; Blond, Emilie; Zobairi, Fatiha; Mely, Yves; Hasselmann, Michel; Toti, Florence; Meziani, Ferhat

2014-11-01

The aim of this study was to assess how lipid emulsions for parenteral nutrition affect lipopolysaccharide (LPS)-induced acute monocyte inflammation in vitro. An 18 h long LPS induced human monocyte leukemia cell stimulation was performed and the cell-growth medium was supplemented with three different industrial lipid emulsions: Intralipid(®), containing long-chain triglycerides (LCT--soybean oil); Medialipid(®), containing LCT (soybean oil) and medium-chain triglycerides (MCT--coconut oil); and SMOFlipid(®), containing LCT, MCT, omega-9 and -3 (soybean, coconut, olive and fish oils). Cell viability and apoptosis were assessed by Trypan blue exclusion and flow cytometry respectively. Monocyte composition and membrane remodeling were studied using gas chromatography and NR12S staining. Microparticles released in supernatant were measured by prothrombinase assay. After LPS challenge, both cellular necrosis and apoptosis were increased (threefold and twofold respectively) and microparticle release was enhanced (sevenfold) after supplementation with Medialipid(®) compared to Intralipid(®), SMOFlipid(®) and monocytes in the standard medium. The monocytes differentially incorporated fatty acids after lipid emulsion challenge. Finally, lipid-treated cells displayed microparticles characterized by disrupted membrane lipid order, reflecting lipid remodeling of the parental cell plasma membrane. Our data suggest that lipid emulsions differentially alter cell viability, monocyte composition and thereby microparticle release. While MCT have deleterious effects, we have shown that parenteral nutrition emulsion containing LCT or LCT and MCT associated to n-3 and n-9 fatty acids have no effect on endotoxin-induced cell death and inflammation.

Uremic Conditions Drive Human Monocytes to Pro-Atherogenic Differentiation via an Angiotensin-Dependent Mechanism

PubMed Central

Trojanowicz, Bogusz; Ulrich, Christof; Seibert, Eric; Fiedler, Roman; Girndt, Matthias

2014-01-01

Aims Elevated expression levels of monocytic-ACE have been found in haemodialysis patients. They are not only epidemiologically linked with increased mortality and cardiovascular disease, but may also directly participate in the initial steps of atherosclerosis. To further address this question we tested the role of monocytic-ACE in promotion of atherosclerotic events in vitro under conditions mimicking those of chronic renal failure. Methods and Results Treatment of human primary monocytes or THP-1 cells with uremic serum as well as PMA-induced differentiation led to significantly up-regulated expression of ACE, further increased by additional treatment with LPS. Functionally, these monocytes revealed significantly increased adhesion and transmigration through endothelial monolayers. Overexpression of ACE in transfected monocytes or THP-1 cells led to development of more differentiated, macrophage-like phenotype with up-regulated expression of Arg1, MCSF, MCP-1 and CCR2. Expression of pro-inflammatory cytokines TNFa and IL-6 were also noticeably up-regulated. ACE overexpression resulted in significantly increased adhesion and transmigration properties. Transcriptional screening of ACE-overexpressing monocytes revealed noticeably increased expression of Angiotensin II receptors and adhesion- as well as atherosclerosis-related ICAM-1 and VCAM1. Inhibition of monocyte ACE or AngII-receptor signalling led to decreased adhesion potential of ACE-overexpressing cells. Conclusions Taken together, these data demonstrate that uremia induced expression of monocytic-ACE mediates the development of highly pro-atherogenic cells via an AngII-dependent mechanism. PMID:25003524

Role of monocyte recruitment in hemangiosarcoma metastasis in dogs.

PubMed

Regan, D P; Escaffi, A; Coy, J; Kurihara, J; Dow, S W

2017-12-01

Canine hemangiosarcoma (HSA) is a highly malignant tumour associated with short survival times because of early and widespread metastasis. In humans and rodents, monocytes play key roles in promoting tumour metastasis through stimulating tumour cell extravasation, seeding, growth and angiogenesis. Therefore, we investigated the potential association between monocyte infiltration and tumour metastasis in HSA and other common canine tumours. Immunohistochemistry was used to quantify CD18 + monocytes within metastases. We found that HSA metastases had significantly greater numbers of CD18 + monocytes compared with metastases from other tumour types. HSA cells were the highest producers of the monocyte chemokine CCL2, and stimulated canine monocyte migration in a CCL2 dependent manner. These results are consistent with the hypothesis that overexpression of CCL2 and recruitment of large numbers of monocytes may explain in part the aggressive metastatic nature of canine HSA. Thus, therapies designed to block monocyte recruitment may be an effective adjuvant strategy for suppressing HSA metastasis in dogs. © 2016 John Wiley & Sons Ltd.

[Molecular mechanism involved in adhesion of monocytes to endothelial cells induced by nicotine and Porphyromonas gingivalis-LPS].

PubMed

Wang, Yi-xiang; An, Na; Ouyang, Xiang-ying

2015-10-18

To investigate molecular mechanism involved in nicotine in combination with Porphyromonas gingivalis (P.g) caused monocyte-endothelial cell adhesion. The effect of nicotine, P.g-lipopolysaccharide (P.g-LPS) and their combination on the proliferation of U937 cells was determined by CCK-8 method. Interleukin-6 (IL-6) expression was investigated by real-time PCR after U937 cells were treated with nicotine, P.g-LPS and their combination. In human umbilical vein endothelial cells (HUVECs), the expressions of monocyte chemoattractant protein CCL-8 and adhesion molecules including vascular cell adhesion molecule 1 (Vcam-1), very late antigen 4 alpha (VLA4α), tumor necrosis factor receptor superfamily member 4 (OX40) and OX40 ligand (OX40L) were detected by real-time PCR or Western blotting assays after HUVEC cells were treated with nicotine, P.g-LPS and their combination. Adhesion of monocytes to endothelial cells was detected after the HUVECs and U937 cells were stimulated with nicotine, P.g-LPS and their combination, respectively. P.g-LPS did not affect the proliferative ability of nicotine in U937 cells. However, the ability of P.g-LPS induced IL-6 expression was inhibited by 100 μmol/L nicotine in U937 cells. In HUVECs, the expressions of CCL-8, Vcam-1, VLA4α, OX40 and OX40L were significantly up-regulated by nicotine and P.g-LPS combination compared with nicotine alone, P.g-LPS alone and the untreated control. Adhesion of monocytes to HUVECs results showed that the two types of cells treated with nicotine in combination with P.g-LPS could markedly increase the adhesion ability of monocytes to HUVECs. P.g-LPS in combination with nicotine could recruit monocytes to endothelial lesion through up-regulation of CCL-8, and promote adhesion of monocytes to endothelial cells through enhancement of Vcam-1/VLA4α and OX40/OX40L interactions, which could be involved in the initiation and development of atherosclerosis.

Imbalance of Circulating Monocyte Subsets and PD-1 Dysregulation in Q Fever Endocarditis: The Role of IL-10 in PD-1 Modulation

PubMed Central

Ka, Mignane B.; Gondois-Rey, Françoise; Capo, Christian; Textoris, Julien; Million, Mathieu; Raoult, Didier; Olive, Daniel; Mege, Jean-Louis

2014-01-01

Q fever endocarditis, a severe complication of Q fever, is associated with a defective immune response, the mechanisms of which are poorly understood. We hypothesized that Q fever immune deficiency is related to altered distribution and activation of circulating monocyte subsets. Monocyte subsets were analyzed by flow cytometry in peripheral blood mononuclear cells from patients with Q fever endocarditis and controls. The proportion of classical monocytes (CD14+CD16− monocytes) was similar in patients and controls. In contrast, the patients with Q fever endocarditis exhibited a decrease in the non-classical and intermediate subsets of monocytes (CD16+ monocytes). The altered distribution of monocyte subsets in Q fever endocarditis was associated with changes in their activation profile. Indeed, the expression of HLA-DR, a canonical activation molecule, and PD-1, a co-inhibitory molecule, was increased in intermediate monocytes. This profile was not restricted to CD16+ monocytes because CD4+ T cells also overexpressed PD-1. The mechanism leading to the overexpression of PD-1 did not require the LPS from C. burnetii but involved interleukin-10, an immunosuppressive cytokine. Indeed, the incubation of control monocytes with interleukin-10 led to a higher expression of PD-1 and neutralizing interleukin-10 prevented C. burnetii-stimulated PD-1 expression. Taken together, these results show that the immune suppression of Q fever endocarditis involves a cross-talk between monocytes and CD4+ T cells expressing PD-1. The expression of PD-1 may be useful to assess chronic immune alterations in Q fever endocarditis. PMID:25211350

Myeloid-derived suppressor activity is mediated by monocytic lineages maintained by continuous inhibition of extrinsic and intrinsic death pathways.

PubMed

Haverkamp, Jessica M; Smith, Amber M; Weinlich, Ricardo; Dillon, Christopher P; Qualls, Joseph E; Neale, Geoffrey; Koss, Brian; Kim, Young; Bronte, Vincenzo; Herold, Marco J; Green, Douglas R; Opferman, Joseph T; Murray, Peter J

2014-12-18

Nonresolving inflammation expands a heterogeneous population of myeloid suppressor cells capable of inhibiting T cell function. This heterogeneity has confounded the functional dissection of individual myeloid subpopulations and presents an obstacle for antitumor immunity and immunotherapy. Using genetic manipulation of cell death pathways, we found the monocytic suppressor-cell subset, but not the granulocytic subset, requires continuous c-FLIP expression to prevent caspase-8-dependent, RIPK3-independent cell death. Development of the granulocyte subset requires MCL-1-mediated control of the intrinsic mitochondrial death pathway. Monocytic suppressors tolerate the absence of MCL-1 provided cytokines increase expression of the MCL-1-related protein A1. Monocytic suppressors mediate T cell suppression, whereas their granulocytic counterparts lack suppressive function. The loss of the granulocytic subset via conditional MCL-1 deletion did not alter tumor incidence implicating the monocytic compartment as the functionally immunosuppressive subset in vivo. Thus, death pathway modulation defines the development, survival, and function of myeloid suppressor cells. Copyright © 2014 Elsevier Inc. All rights reserved.

PGE2 pulsing of murine bone marrow cells reduces migration of daughter monocytes/macrophages in vitro and in vivo

PubMed Central

McGonigle, Terence A.; Dwyer, Amy R.; Greenland, Eloise L.; Scott, Naomi M.; Keane, Kevin N.; Newsholme, Philip; Goodridge, Helen S.; Zon, Leonard I.; Pixley, Fiona J.; Hart, Prue H.

2018-01-01

Monocytes/macrophages differentiating from bone marrow (BM) cells pulsed for 2 hours at 37°C with a stabilized derivative of prostaglandin E2, 16,16-dimethyl PGE2 (dmPGE2), migrated less efficiently toward a chemoattractant than monocytes/macrophages differentiated from BM cells pulsed with vehicle. To confirm that the effect on BM cells was long lasting and to replicate human BM transplantation, chimeric mice were established with donor BM cells pulsed for 2 hours with dmPGE2 before injection into marrow-ablated congenic recipient mice. After 12 weeks, when high levels (90%) of engraftment were obtained, regenerated BM-derived monocytes/macrophages differentiating in vitro or in vivo migrated inefficiently toward the chemokines colony-stimulating factor-1 (CSF-1) and chemokine (C-C motif) ligand 2 (CCL2) or thioglycollate, respectively. Our results reveal long-lasting changes to progenitor cells of monocytes/macrophages by a 2-hour dmPGE2 pulse that, in turn, limits the migration of their daughter cells to chemoattractants and inflammatory mediators. PMID:28822771

A Combination of Ex vivo Diffusion MRI and Multiphoton to Study Microglia/Monocytes Alterations after Spinal Cord Injury

PubMed Central

Noristani, Harun N.; Boukhaddaoui, Hassan; Saint-Martin, Guillaume; Auzer, Pauline; Sidiboulenouar, Rahima; Lonjon, Nicolas; Alibert, Eric; Tricaud, Nicolas; Goze-Bac, Christophe; Coillot, Christophe; Perrin, Florence E.

2017-01-01

Central nervous system (CNS) injury has been observed to lead to microglia activation and monocytes infiltration at the lesion site. Ex vivo diffusion magnetic resonance imaging (diffusion MRI or DWI) allows detailed examination of CNS tissues, and recent advances in clearing procedures allow detailed imaging of fluorescent-labeled cells at high resolution. No study has yet combined ex vivo diffusion MRI and clearing procedures to establish a possible link between microglia/monocytes response and diffusion coefficient in the context of spinal cord injury (SCI). We carried out ex vivo MRI of the spinal cord at different time-points after spinal cord transection followed by tetrahydrofuran based clearing and examined the density and morphology of microglia/monocytes using two-photon microscopy. Quantitative analysis revealed an early marked increase in microglial/monocytes density that is associated with an increase in the extension of the lesion measured using diffusion MRI. Morphological examination of microglia/monocytes somata at the lesion site revealed a significant increase in their surface area and volume as early as 72 hours post-injury. Time-course analysis showed differential microglial/monocytes response rostral and caudal to the lesion site. Microglia/monocytes showed a decrease in reactivity over time caudal to the lesion site, but an increase was observed rostrally. Direct comparison of microglia/monocytes morphology, obtained through multiphoton, and the longitudinal apparent diffusion coefficient (ADC), measured with diffusion MRI, highlighted that axonal integrity does not correlate with the density of microglia/monocytes or their somata morphology. We emphasize that differential microglial/monocytes reactivity rostral and caudal to the lesion site may thus coincide, at least partially, with reported temporal differences in debris clearance. Our study demonstrates that the combination of ex vivo diffusion MRI and two-photon microscopy may be used to follow structural tissue alteration. Lesion extension coincides with microglia/monocytes density; however, a direct relationship between ADC and microglia/monocytes density and morphology was not observed. We highlighted a differential rostro-caudal microglia/monocytes reactivity that may correspond to a temporal difference in debris clearance and axonal integrity. Thus, potential therapeutic strategies targeting microglia/monocytes after SCI may need to be adjusted not only with the time after injury but also relative to the location to the lesion site. PMID:28769787

Endogenous oncogenic Nras mutation promotes aberrant GM-CSF signaling in granulocytic/monocytic precursors in a murine model of chronic myelomonocytic leukemia.

PubMed

Wang, Jinyong; Liu, Yangang; Li, Zeyang; Du, Juan; Ryu, Myung-Jeom; Taylor, Philip R; Fleming, Mark D; Young, Ken H; Pitot, Henry; Zhang, Jing

2010-12-23

Oncogenic NRAS mutations are frequently identified in myeloid diseases involving monocyte lineage. However, its role in the genesis of these diseases remains elusive. We report a mouse bone marrow transplantation model harboring an oncogenic G12D mutation in the Nras locus. Approximately 95% of recipient mice develop a myeloproliferative disease resembling the myeloproliferative variant of chronic myelomonocytic leukemia (CMML), with a prolonged latency and acquisition of multiple genetic alterations, including uniparental disomy of oncogenic Nras allele. Based on single-cell profiling of phospho-proteins, a novel population of CMML cells is identified to display aberrant granulocyte-macrophage colony stimulating factor (GM-CSF) signaling in both the extracellular signal-regulated kinase (ERK) 1/2 and signal transducer and activator of transcription 5 (Stat5) pathways. This abnormal signaling is acquired during CMML development. Further study suggests that aberrant Ras/ERK signaling leads to expansion of granulocytic/monocytic precursors, which are highly responsive to GM-CSF. Hyperactivation of Stat5 in CMML cells is mainly through expansion of these precursors rather than up-regulation of surface expression of GM-CSF receptors. Our results provide insights into the aberrant cytokine signaling in oncogenic NRAS-associated myeloid diseases.

Autologous NeoHep Derived from Chronic Hepatitis B Virus Patients’ Blood Monocytes by Upregulation of c‐MET Signaling

PubMed Central

Bhattacharjee, Jashdeep; Das, Barun; Sharma, Disha; Sahay, Preeti; Jain, Kshama; Mishra, Alaknanda; Iyer, Srikanth; Nagpal, Puja; Scaria, Vinod; Nagarajan, Perumal; Khanduri, Prakash; Mukhopadhyay, Asok

2016-01-01

Abstract In view of the escalating need for autologous cell‐based therapy for treatment of liver diseases, a novel candidate has been explored in the present study. The monocytes isolated from hepatitis B surface antigen (HBsAg) nucleic acid test (NAT)‐positive (HNP) blood were differentiated to hepatocyte‐like cells (NeoHep) in vitro by a two‐step culture procedure. The excess neutrophils present in HNP blood were removed before setting up the culture. In the first step of culture, apoptotic cells were depleted and genes involved in hypoxia were induced, which was followed by the upregulation of genes involved in the c‐MET signaling pathway in the second step. The NeoHep were void of hepatitis B virus and showed expression of albumin, connexin 32, hepatocyte nuclear factor 4‐α, and functions such as albumin secretion and cytochrome P450 enzyme‐mediated detoxification of xenobiotics. The engraftment of NeoHep derived from HBsAg‐NAT‐positive blood monocytes in partially hepatectomized NOD.CB17‐Prkdcscid/J mice liver and the subsequent secretion of human albumin and clotting factor VII activity in serum make NeoHep a promising candidate for cell‐based therapy. Stem Cells Translational Medicine 2017;6:174–186 PMID:28170202

Phenotypic and functional comparison of two distinct subsets of programmable cell of monocytic origin (PCMOs)-derived dendritic cells with conventional monocyte-derived dendritic cells

PubMed Central

Beikzadeh, Babak; Delirezh, Nowruz

2016-01-01

Dendritic cells (DCs) are professional antigen-presenting cells with the ability to induce primary T-cell responses. They are commonly produced by culturing monocytes in the presence of IL-4 and GM-CSF (cells produced in this manner are called conventional DCs). Here we report the generation of two functionally distinct subsets of DCs derived from programmable cells of monocytic origin (PCMOs) in the presence of IL-3 or tumor necrosis factor alpha (TNF-α). Monocytes were treated with macrophage colony-stimulating factor (M-CSF) and IL-3 for 6 days and then incubated with IL-4 and IL-3 (for IL-3 DCs) or with IL-4, GM-CSF and TNF-α (for TNF-α DCs) for 7 days. Monocytes were then loaded with tumor lysate (used as antigen), and poly (I∶C) was added. The maturation factors TNF-α and monocyte conditioned medium (MCM) were added on days 4 and 5, respectively. The phenotypes of the DCs generated were characterized by flow cytometry, and the cells' phagocytic activities were measured using FITC-conjugated latex bead uptake. T-cell proliferation and cytokine release were assayed using MTT and commercially available ELISA kits, respectively. We found that either IL-3DCs or TNF-α DCs induce T-cell proliferation and cytokine secretion; the cytokine release pattern showed reduced IL-12/IL-10 and IFN-γ/IL-4 ratios in both types of DCs and in DC-primed T-cell supernatant, respectively, which confirmed that the primed T cells were polarized toward aTh2-type immune response. We concluded that PCMOs are a new cell source that can develop into two functionally distinct DCs that both induce a Th2-type response in vitro. This modality can be used as a DC-based immunotherapy for autoimmune diseases. PMID:25661728

Cross-talk between iNKT cells and monocytes triggers an atheroprotective immune response in SLE patients with asymptomatic plaque.

PubMed

Smith, Edward; Croca, Sara; Waddington, Kirsty E; Sofat, Reecha; Griffin, Maura; Nicolaides, Andrew; Isenberg, David A; Torra, Ines Pineda; Rahman, Anisur; Jury, Elizabeth C

2016-12-02

Accelerated atherosclerosis is a complication of the autoimmune rheumatic disease systemic lupus erythematosus (SLE). We questioned the role played by invariant natural killer T (iNKT) cells in this process because they not only are defective in autoimmunity but also promote atherosclerosis in response to CD1d-mediated lipid antigen presentation. iNKT cells from SLE patients with asymptomatic plaque (SLE-P) had increased proliferation and interleukin-4 production compared with those from SLE patients with no plaque. The anti-inflammatory iNKT cell phenotype was associated with dyslipidemia and was driven by altered monocyte phospholipid expression and CD1d-mediated cross-talk between iNKT cells and monocytes but not B cells. Healthy iNKT cells differentiated in the presence of healthy monocytes and SLE-P serum polarized macrophages toward an anti-inflammatory M2 phenotype. Conversely, patients with clinical cardiovascular disease had unresponsive iNKT cells and increased proinflammatory monocytes. iNKT cell function could link immune responses, lipids, and cardiovascular disease in SLE patients and, together with serum lipid taxonomy, help predict preclinical atherosclerosis in SLE patients. Copyright © 2016, American Association for the Advancement of Science.

HSV-1-induced activation of NF-κB protects U937 monocytic cells against both virus replication and apoptosis

PubMed Central

Marino-Merlo, Francesca; Papaianni, Emanuela; Medici, Maria Antonietta; Macchi, Beatrice; Grelli, Sandro; Mosca, Claudia; Borner, Christoph; Mastino, Antonio

2016-01-01

The transcription factor nuclear factor-kappa B (NF-κB) is a crucial player of the antiviral innate response. Intriguingly, however, NF-κB activation is assumed to favour herpes simplex virus (HSV) infection rather than restrict it. Apoptosis, a form of innate response to viruses, is completely inhibited by HSV in fully permissive cells, but not in cells incapable to fully sustain HSV replication, such as immunocompetent cells. To resolve the intricate interplay among NF-κB signalling, apoptosis and permissiveness to HSV-1 in monocytic cells, we utilized U937 monocytic cells in which NF-κB activation was inhibited by expressing a dominant-negative IκBα. Surprisingly, viral production was increased in monocytic cells in which NF-κB was inhibited. Moreover, inhibition of NF-κB led to increased apoptosis following HSV-1 infection, associated with lysosomal membrane permeabilization. High expression of late viral proteins and induction of apoptosis occurred in distinct cells. Transcriptional analysis of known innate response genes by real-time quantitative reverse transcription-PCR excluded a contribution of the assayed genes to the observed phenomena. Thus, in monocytic cells NF-κB activation simultaneously serves as an innate process to restrict viral replication as well as a mechanism to limit the damage of an excessive apoptotic response to HSV-1 infection. This finding may clarify mechanisms controlling HSV-1 infection in monocytic cells. PMID:27584793

Cancer Cell-derived Exosomes Induce Mitogen-activated Protein Kinase-dependent Monocyte Survival by Transport of Functional Receptor Tyrosine Kinases.

PubMed

Song, Xiao; Ding, Yanping; Liu, Gang; Yang, Xiao; Zhao, Ruifang; Zhang, Yinlong; Zhao, Xiao; Anderson, Gregory J; Nie, Guangjun

2016-04-15

Tumor-associated macrophages (TAM) play pivotal roles in cancer initiation and progression. Monocytes, the precursors of TAMs, normally undergo spontaneous apoptosis within 2 days, but can subsist in the inflammatory tumor microenvironment for continuous survival and generation of sufficient TAMs. The mechanisms underlying tumor-driving monocyte survival remain obscure. Here we report that cancer cell-derived exosomes were crucial mediators for monocyte survival in the inflammatory niche. Analysis of the survival-promoting molecules in monocytes revealed that cancer cell-derived exosomes activated Ras and extracellular signal-regulated kinases in the mitogen-activated protein kinase (MAPK) pathway, resulting in the prevention of caspase cleavage. Phosphorylated receptor tyrosine kinases (RTKs), such as phosphorylated epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2), were abundantly expressed in cancer cell-derived exosomes. Knock-out of EGFR or/and HER-2, or alternatively, inhibitors against their phosphorylation significantly disturbed the exosome-mediated activation of the MAPK pathway, inhibition of caspase cleavage, and increase in survival rate in monocytes. Moreover, the deprived survival-stimulating activity of exosomes due to null expression of EGFR and HER-2 could be restored by activation of another RTK, insulin receptor. Overall, our study uncovered a mechanism of tumor-associated monocyte survival and demonstrated that cancer cell-derived exosomes can stimulate the MAPK pathway in monocytes through transport of functional RTKs, leading to inactivation of apoptosis-related caspases. This work provides insights into the long sought question on monocyte survival prior to formation of plentiful TAMs in the tumor microenvironment. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Functional Relevance of Protein Glycosylation to the Pro-Inflammatory Effects of Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) on Monocytes/Macrophages

PubMed Central

Ge, Heng; Yuan, Wei; Liu, Jidong; He, Qing; Ding, Song; Pu, Jun; He, Ben

2015-01-01

Background and Objective Extracellular matrix metalloproteinase inducer (EMMPRIN) is an important pro-inflammatory protein involved in the cellular functions of monocytes/macrophages. We have hypothesized that high-level heterogeneousness of protein glycosylation of EMMPRIN may have functional relevance to its biological effects and affect the inflammatory activity of monocytes/macrophages. Methods The glycosylation patterns of EMMPRIN expressed by monocytes/macrophages (THP-1 cells) in response to different extracellular stimuli were observed, and the structures of different glycosylation forms were identified. After the purification of highly- and less-glycosylated proteins respectively, the impacts of different glycosylation forms on the pro-inflammatory effects of EMMPRIN were examined in various aspects, such as cell adhesion to endothelial cells, cell migrations, cytokine expression, and activation of inflammatory signalling pathway. Results 1) It was mainly the highly-glycosylated form of EMMPRIN (HG-EMMPRIN) that increased after being exposed to inflammatory signals (PMA and H2O2). 2) Glycosylation of EMMPRIN in monocytes/macrophages led to N-linked-glycans being added to the protein, with the HG form containing complex-type glycans and the less-glycosylated form (LG) the simple type. 3) Only the HG-EMMPRIN but not the LG-EMMPRIN exhibited pro-inflammatory effects and stimulated inflammatory activities of the monocytes/macrophages (i.e., activation of ERK1/2 and NF-κB pathway, enhanced monocyte-endothelium adhesion, cell migration and matrix metalloproteinase -9 expression). Conclusions Post-transcriptional glycosylation represents an important mechanism that determines the biological effects of EMMPRIN in monocytes/macrophages. Glycosylation of EMMPRIN may serve as a potential target for regulating the inflammatory activities of monocytes/macrophages. PMID:25658763

Histaminergic regulation of NK-cells: protection against monocyte-induced apoptosis.

PubMed

Hansson, M; Asea, A; Hermodsson, S; Hellstrand, K

1996-08-01

Human natural killer (NK) cells (with CD3-/56+ phenotype) acquired features characteristic of apoptosis after incubation with autologous monocytes, as revealed by apoptotic nuclear morphology and degradation of DNA into oligonucleosomal fragments. The monocyte-induced apoptosis in NK-cells was prevented by the biogenic amine histamine at concentrations exceeding 0.1 microM. The protective effect of histamine was blocked by the H2-receptor (H2R) antagonist ranitidine but not by AH202399 A, a chemical control to ranitidine devoid of H2R affinity. It is concluded that histaminergic mechanisms may serve to protect NK cells from damage inflicted by products of the oxidative metabolism of monocytes.

In vitro interaction of Stenotrophomonas maltophilia with human monocyte-derived dendritic cells.

PubMed

Roscetto, Emanuela; Vitiello, Laura; Muoio, Rosa; Soriano, Amata A; Iula, Vita D; Vollaro, Antonio; De Gregorio, Eliana; Catania, Maria R

2015-01-01

Stenotrophomonas maltophilia is increasingly identified as an opportunistic pathogen in immunocompromised, cancer and cystic fibrosis (CF) patients. Knowledge on innate immune responses to S. maltophilia and its potential modulation is poor. The present work investigated the ability of 12 clinical S. maltophilia strains (five from CF patients, seven from non-CF patients) and one environmental strain to survive inside human monocyte-derived dendritic cells (DCs). The effects of the bacteria on maturation of and cytokine secretion by DCs were also measured. S. maltophilia strains presented a high degree of heterogeneity in internalization and intracellular replication efficiencies as well as in the ability of S. maltophilia to interfere with normal DCs maturation. By contrast, all S. maltophilia strains were able to activate DCs, as measured by increase in the expression of surface maturation markers and proinflammatory cytokines secretion.

In vitro interaction of Stenotrophomonas maltophilia with human monocyte-derived dendritic cells

PubMed Central

Roscetto, Emanuela; Vitiello, Laura; Muoio, Rosa; Soriano, Amata A.; Iula, Vita D.; Vollaro, Antonio; Gregorio, Eliana De; Catania, Maria R.

2015-01-01

Stenotrophomonas maltophilia is increasingly identified as an opportunistic pathogen in immunocompromised, cancer and cystic fibrosis (CF) patients. Knowledge on innate immune responses to S. maltophilia and its potential modulation is poor. The present work investigated the ability of 12 clinical S. maltophilia strains (five from CF patients, seven from non-CF patients) and one environmental strain to survive inside human monocyte-derived dendritic cells (DCs). The effects of the bacteria on maturation of and cytokine secretion by DCs were also measured. S. maltophilia strains presented a high degree of heterogeneity in internalization and intracellular replication efficiencies as well as in the ability of S. maltophilia to interfere with normal DCs maturation. By contrast, all S. maltophilia strains were able to activate DCs, as measured by increase in the expression of surface maturation markers and proinflammatory cytokines secretion. PMID:26236302

Effector CD4+ T cells recognize intravascular antigen presented by patrolling monocytes.

PubMed

Westhorpe, Clare L V; Norman, M Ursula; Hall, Pam; Snelgrove, Sarah L; Finsterbusch, Michaela; Li, Anqi; Lo, Camden; Tan, Zhe Hao; Li, Songhui; Nilsson, Susan K; Kitching, A Richard; Hickey, Michael J

2018-02-21

Although effector CD4 + T cells readily respond to antigen outside the vasculature, how they respond to intravascular antigens is unknown. Here we show the process of intravascular antigen recognition using intravital multiphoton microscopy of glomeruli. CD4 + T cells undergo intravascular migration within uninflamed glomeruli. Similarly, while MHCII is not expressed by intrinsic glomerular cells, intravascular MHCII-expressing immune cells patrol glomerular capillaries, interacting with CD4 + T cells. Following intravascular deposition of antigen in glomeruli, effector CD4 + T-cell responses, including NFAT1 nuclear translocation and decreased migration, are consistent with antigen recognition. Of the MHCII + immune cells adherent in glomerular capillaries, only monocytes are retained for prolonged durations. These cells can also induce T-cell proliferation in vitro. Moreover, monocyte depletion reduces CD4 + T-cell-dependent glomerular inflammation. These findings indicate that MHCII + monocytes patrolling the glomerular microvasculature can present intravascular antigen to CD4 + T cells within glomerular capillaries, leading to antigen-dependent inflammation.

Gas6 Promotes Inflammatory (CCR2hiCX3CR1lo) Monocyte Recruitment in Venous Thrombosis.

PubMed

Laurance, Sandrine; Bertin, François-René; Ebrahimian, Talin; Kassim, Yusra; Rys, Ryan N; Lehoux, Stéphanie; Lemarié, Catherine A; Blostein, Mark D

2017-07-01

Coagulation and inflammation are inter-related. Gas6 (growth arrest-specific 6) promotes venous thrombosis and participates to inflammation through endothelial-innate immune cell interactions. Innate immune cells can provide the initiating stimulus for venous thrombus development. We hypothesize that Gas6 promotes monocyte recruitment during venous thrombosis. Deep venous thrombosis was induced in wild-type and Gas6-deficient (-/-) mice using 5% FeCl 3 and flow reduction in the inferior vena cava. Total monocyte depletion was achieved by injection of clodronate before deep venous thrombosis. Inflammatory monocytes were depleted using an anti-C-C chemokine receptor type 2 (CCR2) antibody. Similarly, injection of an anti-chemokine ligand 2 (CCL2) antibody induced CCL2 depletion. Flow cytometry and immunofluorescence were used to characterize the monocytes recruited to the thrombus. In vivo, absence of Gas6 was associated with a reduction of monocyte recruitment in both deep venous thrombosis models. Global monocyte depletion by clodronate leads to smaller thrombi in wild-type mice. Compared with wild type, the thrombi from Gas6 -/- mice contain less inflammatory (CCR2 hi CX 3 CR1 lo ) monocytes, consistent with a Gas6-dependent recruitment of this monocyte subset. Correspondingly, selective depletion of CCR2 hi CX 3 CR1 lo monocytes reduced the formation of venous thrombi in wild-type mice demonstrating a predominant role of the inflammatory monocytes in thrombosis. In vitro, the expression of both CCR2 and CCL2 were Gas6 dependent in monocytes and endothelial cells, respectively, impacting monocyte migration. Moreover, Gas6-dependent CCL2 expression and monocyte migration were mediated via JNK (c-Jun N-terminal kinase). This study demonstrates that Gas6 specifically promotes the recruitment of inflammatory CCR2 hi CX 3 CR1 lo monocytes through the regulation of both CCR2 and CCL2 during deep venous thrombosis. © 2017 American Heart Association, Inc.

Antibody-Dependent Cell-Mediated Cytotoxicity Effector-Enhanced EphA2 Agonist Monoclonal Antibody Demonstrates Potent Activity against Human Tumors1

PubMed Central

Bruckheimer, Elizabeth M; Fazenbaker, Christine A; Gallagher, Sandra; Mulgrew, Kathy; Fuhrmann, Stacy; Coffman, Karen T; Walsh, William; Ready, Shannon; Cook, Kim; Damschroder, Melissa; Kinch, Michael; Kiener, Peter A; Woods, Rob; Gao, Changshou; Dall'Acqua, William; Wu, Herren; Coats, Steven

2009-01-01

EphA2 is a receptor tyrosine kinase that has been shown to be overexpressed in a variety of human tumor types. Previous studies demonstrated that agonist monoclonal antibodies targeting EphA2 induced the internalization and degradation of the receptor, thereby abolishing its oncogenic effects. In this study, the in vitro and in vivo antibody-dependent cell-mediated cytotoxicity (ADCC) activity of EphA2 effector-enhanced agonist monoclonal antibodies was evaluated. With tumor cell lines and healthy human peripheral blood monocytes, the EphA2 antibodies demonstrated ∼80% tumor cell killing. In a dose-dependent manner, natural killer (NK) cells were required for the in vitro ADCC activity and became activated as demonstrated by the induction of cell surface expression of CD107a. To assess the role of NK cells on antitumor efficacy in vivo, the EphA2 antibodies were evaluated in xenograft models in severe compromised immunodeficient (SCID) mice (which have functional NK cells and monocytes) and SCID nonobese diabetic (NOD) mice (which largely lack functional NK cells and monocytes). Dosing of EphA2 antibody in the SCID murine tumor model resulted in a 6.2-fold reduction in tumor volume, whereas the SCID/nonobese diabetic model showed a 1.6-fold reduction over the isotype controls. Together, these results demonstrate that the anti-EphA2 monoclonal antibodies may function through at least two mechanisms of action: EphA2 receptor activation and ADCC-mediated activity. These novel EphA2 monoclonal antibodies provide additional means by which host effector mechanisms can be activated for selective destruction of EphA2-expressing tumor cells. PMID:19484140

Uncoupling between CD1d upregulation induced by retinoic acid and conduritol-B-epoxide and iNKT cell responsiveness.

PubMed

Balreira, Andrea; Cavallari, Marco; Sá Miranda, Maria Clara; Arosa, Fernando A

2010-06-01

Gaucher disease (GD) is associated with upregulation of CD1d and MHC-class II expression by monocytes. While the physiological impact of CD1d upregulation remains uncertain, it has been proposed that MHC-class II upregulation is associated with inflammation. Hereby, we show that the decrease in MHC-class II expression seen in GD patients under therapy correlates positively with chitotriosidase activity, a marker of inflamed macrophages. We also show that retinoic acid (RA) and the beta-glucocerebrosidase inhibitor conduritol-B-epoxide (CBE) lead to upregulation of CD1d expression by THP-1 cells, which correlated with an increase in mRNA expression. In vitro co-culture experiments showed that RA treated THP-1 cells were more stimulatory for CD4(+) than for CD8(+) T cells, as determined by CFSE loss, in comparison to untreated THP-1 cells. Interestingly, even though addition of exogenous isoglobotrihexosylceramide (iGb3), a physiological CD1d ligand, augmented the percentage of dividing CD4(+) T cells, we could not detect a significant expansion of CD4(+)Valpha24(+) invariant Natural Killer T (iNKT) cells. In contrast, addition of alpha-galactosylceramide (alpha-GC) induced expansion of Valpha24(+) iNKT cells as determined by using alpha-GC-loaded human CD1d dimers. These results strengthen the existence of a cross-talk between monocyte lipid accumulation, inflammation and changes in cell surface CD1d and MHC-class II in monocytes, which may result in inappropriate recognition events by immune cells and perpetuate chronic inflammation. Copyright 2009 Elsevier GmbH. All rights reserved.

Whole Blood Activation Results in Enhanced Detection of T Cell and Monocyte Cytokine Production by Flow Cytometry

NASA Technical Reports Server (NTRS)

Sams, Clarence F.; Crucian, Brian E.

2001-01-01

An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a wholeblood activation culture has been described. We compared whole blood culture to standard PBMC culture and determined the individual cytokine secretion patterns for both T cells and monocytes via flow cytometry. For T cells cytokine assessment following PMA +ionomycin activation: (1) a significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture; (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. In addition, a four-color cytometric analysis was used to allow accurate phenotyping and quantitation of cytokine producing lymphocyte populations. Using this technique we found IFNgamma production to be significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines in conjunction with CD 14. The cytokine pairs used for analysis were IL-1a/IL-12, and IL-10ITNFa. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFalpha equally well in both culture systems. Monocyte production of IL-10 was significantly elevated following whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing monocytes may represent functionally different monocyte subsets with distinct functions. Whole blood culture eliminates the need to purify cell populations prior to culture and may have significant utility for the routine monitoring of the cytokine balances of the peripheral blood T cell and monocyte populations. In addition, there are distinct advantages to performing whole-blood (WB) activation as compared to PBMC activation. These advantages would include retaining all various cell-cell interactions as well as any soluble factors present in serum that influence cell activation. It is likely that the altered cytokine production observed following whole blood culture more accurately represents the in-vivo immune balance.

Atheroprotection through SYK inhibition fails in established disease when local macrophage proliferation dominates lesion progression.

PubMed

Lindau, Alexandra; Härdtner, Carmen; Hergeth, Sonja P; Blanz, Kelly Daryll; Dufner, Bianca; Hoppe, Natalie; Anto-Michel, Nathaly; Kornemann, Jan; Zou, Jiadai; Gerhardt, Louisa M S; Heidt, Timo; Willecke, Florian; Geis, Serjosha; Stachon, Peter; Wolf, Dennis; Libby, Peter; Swirski, Filip K; Robbins, Clinton S; McPheat, William; Hawley, Shaun; Braddock, Martin; Gilsbach, Ralf; Hein, Lutz; von zur Mühlen, Constantin; Bode, Christoph; Zirlik, Andreas; Hilgendorf, Ingo

2016-03-01

Macrophages in the arterial intima sustain chronic inflammation during atherogenesis. Under hypercholesterolemic conditions murine Ly6C(high) monocytes surge in the blood and spleen, infiltrate nascent atherosclerotic plaques, and differentiate into macrophages that proliferate locally as disease progresses. Spleen tyrosine kinase (SYK) may participate in downstream signaling of various receptors that mediate these processes. We tested the effect of the SYK inhibitor fostamatinib on hypercholesterolemia-associated myelopoiesis and plaque formation in Apoe(-/-) mice during early and established atherosclerosis. Mice consuming a high cholesterol diet supplemented with fostamatinib for 8 weeks developed less atherosclerosis. Histologic and flow cytometric analysis of aortic tissue showed that fostamatinib reduced the content of Ly6C(high) monocytes and macrophages. SYK inhibition limited Ly6C(high) monocytosis through interference with GM-CSF/IL-3 stimulated myelopoiesis, attenuated cell adhesion to the intimal surface, and blocked M-CSF stimulated monocyte to macrophage differentiation. In Apoe(-/-) mice with established atherosclerosis, however, fostamatinib treatment did not limit macrophage accumulation or lesion progression despite a significant reduction in blood monocyte counts, as lesional macrophages continued to proliferate. Thus, inhibition of hypercholesterolemia-associated monocytosis, monocyte infiltration, and differentiation by SYK antagonism attenuates early atherogenesis but not established disease when local macrophage proliferation dominates lesion progression.

Serum amyloid A secretion from monocytic leukaemia cell line THP-1 and cultured human peripheral monocytes.

PubMed

Yamada, T; Wada, A; Itoh, K; Igari, J

2000-07-01

Serum amyloid A (SAA), an acute-phase protein and a precursor of fibrous components in reactive amyloid deposits, is synthesized mainly in the liver under the stimulation of inflammation-related cytokines. In addition, the SAA gene is expressed in monocytes/macrophages, which are believed to play a central role in amyloid fibrillogenesis. Consequently, the pathogenic implication of SAA produced from these cells has been of major concern. Because SAA synthesis at the protein level in such cells has never been analyzed quantitatively, in this study an enzyme-linked immunosorbent assay was generated with a detection level sufficiently high to measure SAA concentrations in the culture supernatants of the human monocytic leukaemia cell line THP-1. SAA secretion by THP-1 with interleukin (IL)-1beta required the presence of dexamethasone as proposed previously. We also found that unidentified components in fetal calf serum (FCS) could induce SAA production by THP-1 in the presence of dexamethasone. These findings are in contrast to the results obtained from hepatoma cell line HepG2, in which IL-1beta alone could induce SAA secretion, while dexamethasone-supplemented FCS could not. The method was able to quantify SAA secreted from cultured human peripheral monocytes. The findings suggest that monocytes produce SAA in almost the same manner as THP-1. Thus, THP-1 cells can be utilized to investigate a distinctive manner of SAA production from monocytes.

Therapeutic concentration of lithium stimulates complement C3 production in dendritic cells and microglia via GSK-3 inhibition.

PubMed

Yu, Zhiqian; Ono, Chiaki; Aiba, Setsuya; Kikuchi, Yoshie; Sora, Ichiro; Matsuoka, Hiroo; Tomita, Hiroaki

2015-02-01

Evidence indicates that widely prescribed mood stabilizer, lithium (Li), mediates cellular functions of differentiated monocytic cells, including microglial migration, monocyte-derived dendritic cell (MoDC) differentiation, and amelioration of monocytic malfunctions observed in neuropsychiatric diseases. Here, we surveyed molecules which take major roles in regulating these monocytic cellular functions. MoDCs treated with 1 and 5 mM Li, and microglia separated from Li-treated mice were subjected to microarray-based comprehensive gene expression analyses. Findings were validated using multiple experiments, including quantitative PCR, ELISA and immunostaining studies. Differing effects of Li on the two cell types were observed. Inflammation- and chemotaxis-relevant genes were significantly over-represented among Li-induced genes in MoDCs, whereas no specific category of genes was over-represented in microglia. The third component of complement (C3) was the only gene which was significantly induced by a therapeutic concentration of Li in both MoDCs and microglia. C3 production was increased by Li via GSK-3 inhibition. Li-induced C3 production was seen only in differentiated monocytic cells, but not in circulating monocytes. Our findings highlight a link between Li treatment and C3 production in differentiated monocytic cells, and reveal a regulatory role of GSK-3 in C3 production. Induction of microglial C3 production might be a novel neuroprotective mechanism of Li via regulating interactions between microglia and neurons. GLIA 2015;63:257-270. © 2014 Wiley Periodicals, Inc.

Interleukin-32 induces the differentiation of monocytes into macrophage-like cells.

PubMed

Netea, Mihai G; Lewis, Eli C; Azam, Tania; Joosten, Leo A B; Jaekal, Jun; Bae, Su-Young; Dinarello, Charles A; Kim, Soo-Hyun

2008-03-04

After emigration from the bone marrow to the peripheral blood, monocytes enter tissues and differentiate into macrophages, the prototype scavenger of the immune system. By ingesting and killing microorganisms and removing cellular debris, macrophages also process antigens as a first step in mounting a specific immune response. IL-32 is a cytokine inducing proinflammatory cytokines and chemokines via p38-MAPK and NF-kappaB. In the present study, we demonstrate that IL-32 induces differentiation of human blood monocytes as well as THP-1 leukemic cells into macrophage-like cells with functional phagocytic activity for live bacteria. Muramyl dipepide (MDP), the ligand for the intracellular nuclear oligomerization domain (NOD) 2 receptor, has no effect on differentiation alone but augments the monocyte-to-macrophage differentiation by IL-32. Unexpectedly, IL-32 reversed GM-CSF/IL-4-induced dendritic cell differentiation to macrophage-like cells. Whereas the induction of TNFalpha, IL-1beta, and IL-6 by IL-32 is mediated by p38-MAPK, IL-32-induced monocyte-to-macrophage differentiation is mediated through nonapoptotic, caspase-3-dependent mechanisms. Thus, IL-32 not only contributes to host responses through the induction of proinflammatory cytokines but also directly affects specific immunity by differentiating monocytes into macrophage-like cells.

Ly6CHi Blood Monocyte/Macrophage Drive Chronic Inflammation and Impair Wound Healing in Diabetes Mellitus.

PubMed

Kimball, Andrew; Schaller, Matthew; Joshi, Amrita; Davis, Frank M; denDekker, Aaron; Boniakowski, Anna; Bermick, Jennifer; Obi, Andrea; Moore, Bethany; Henke, Peter K; Kunkel, Steve L; Gallagher, Katherine A

2018-05-01

Wound monocyte-derived macrophage plasticity controls the initiation and resolution of inflammation that is critical for proper healing, however, in diabetes mellitus, the resolution of inflammation fails to occur. In diabetic wounds, the kinetics of blood monocyte recruitment and the mechanisms that control in vivo monocyte/macrophage differentiation remain unknown. Here, we characterized the kinetics and function of Ly6C Hi [Lin - (CD3 - CD19 - NK1.1 - Ter-119 - ) Ly6G - CD11b + ] and Ly6C Lo [Lin - (CD3 - CD19 - NK1.1 - Ter-119 - ) Ly6G - CD11b + ] monocyte/macrophage subsets in normal and diabetic wounds. Using flow-sorted tdTomato -labeled Ly6C Hi monocyte/macrophages, we show Ly6C Hi cells transition to a Ly6C Lo phenotype in normal wounds, whereas in diabetic wounds, there is a late, second influx of Ly6C Hi cells that fail transition to Ly6C Lo . The second wave of Ly6C Hi cells in diabetic wounds corresponded to a spike in MCP-1 (monocyte chemoattractant protein-1) and selective administration of anti-MCP-1 reversed the second Ly6C Hi influx and improved wound healing. To examine the in vivo phenotype of wound monocyte/macrophages, RNA-seq-based transcriptome profiling was performed on flow-sorted Ly6C Hi [Lin - Ly6G - CD11b + ] and Ly6C Lo [Lin - Ly6G - CD11b + ] cells from normal and diabetic wounds. Gene transcriptome profiling of diabetic wound Ly6C Hi cells demonstrated differences in proinflammatory and profibrotic genes compared with controls. Collectively, these data identify kinetic and functional differences in diabetic wound monocyte/macrophages and demonstrate that selective targeting of CD11b + Ly6C Hi monocyte/macrophages is a viable therapeutic strategy for inflammation in diabetic wounds. © 2018 American Heart Association, Inc.

FC-99 ameliorates sepsis-induced liver dysfunction by modulating monocyte/macrophage differentiation via Let-7a related monocytes apoptosis.

PubMed

Zhao, Yarong; Zhu, Haiyan; Wang, Haining; Ding, Liang; Xu, Lizhi; Chen, Dai; Shen, Sunan; Hou, Yayi; Dou, Huan

2018-03-13

The liver is a vital target for sepsis-related injury, leading to inflammatory pathogenesis, multiple organ dysfunction and high mortality rates. Monocyte-derived macrophage transformations are key events in hepatic inflammation. N 1 -[(4-methoxy)methyl]-4-methyl-1,2-benzenediamine (FC-99) previously displayed therapeutic potential on experimental sepsis. However, the underlying mechanism of this protective effect is still not clear. FC-99 treatment attenuated the liver dysfunction in septic mice that was accompanied with reduced numbers of pro-inflammatory Ly6C hi monocytes in the peripheral blood and CD11b + F4/80 lo monocyte-derived macrophages in the liver. These effects were attributed to the FC-99-induced apoptosis of CD11b + cells. In PMA-differentiated THP-1 cells, FC-99 repressed the expression of CD11b, CD14 and caspase3 and resulted in a high proportion of Annexin V + cells. Moreover, let-7a-5p expression was abrogated upon CLP stimulation in vivo , whereas it was restored by FC-99 treatment. TargetScan analysis and luciferase assays indicated that the anti-apoptotic protein BCL-XL was targeted by let-7a-5p. BCL-XL was inhibited by FC-99 in order to induce monocyte apoptosis, leading to the impaired monocyte-to-macrophage differentiation. Murine acute liver failure was generated by caecal ligation puncture surgery after FC-99 administration; Blood samples and liver tissues were collected to determine the monocyte/macrophage subsets and the induction of apoptosis. Human acute monocytic leukemia cell line (THP-1) cells were pretreated with FC-99 followed by phorbol-12-myristate-13-acetate (PMA) stimulation, in order to induce monocyte-to-macrophage differentiation. The target of FC-99 and the mechanistic analyses were conducted by microarrays, qRT-PCR validation, TargetScan algorithms and a luciferase report assay. FC-99 exhibits potential therapeutic effects on CLP-induced liver dysfunction by restoring let-7a-5p levels.

Polymerisation par plasma a pression atmospherique: Caracterisation des depots et leurs applications en biotechnologies

NASA Astrophysics Data System (ADS)

Girard-Lauriault, Pierre-Luc

Nitrogen (N)-containing polymer surfaces are attractive in numerous technological contexts, for example in biomedical applications. Here, we have used an atmospheric-pressure dielectric barrier discharge (DBD) apparatus to deposit novel families of N-rich plasma polymers, designated PP:N, using mixtures of three different hydrocarbon precursors (methane, ethylene, and acetylene) in nitrogen at varying respective gas flow ratios, typically parts per thousand. In preparation for subsequent cell-surface interaction studies, the first part of this research focuses on the chemical mapping of those materials, with specific attention to (semi)- quantitative analyses of functional groups. Well-established and some lesser-known analytical techniques have been combined to provide the best possible chemical and structural characterisations of these three families of PP:N thin films; namely, X-ray photoelectron spectroscopy (XPS), Near-edge X-ray absorption fine structure (NEXAFS), Fourier transform infrared spectroscopy (FTIR), contact angle goniometry (CAG), and elemental analysis (EA). High, "tunable" total nitrogen content was measured by both XPS and EA (between 6% and 25% by EA, or between 10% and 40% by XPS, which cannot detect hydrogen). Chemical derivatisation with 4-trifluoromethylbenzaldehyde (TFBA) enabled measurements of primary amine concentrations, the functionality of greatest bio-technological interest, which were found to account for 5 % to 20 % of the total bound nitrogen. By combining the above-mentioned complementary methods, we were further able to determine the complete chemical formulae, the degrees of unsaturation, and other major chemical functionalities in PP:N film structures. Several of these features are believed to be without precedents in the literature on hydrocarbon plasma polymers, for example measurements of absolute compositions (including hydrogen), and of unsaturation. It was shown that besides amines, nitriles, isonitriles and imines are the main nitrogenated functional groups in those materials. In a second part of this work, we have studied the interraction of these well-characterised surfaces with living cells. We have first demonstrated the adhesion, on both uniformly coated and micro-patterned PP:N deposits on BOPP, of three different cell types, namely, growth plate and articular chondrocytes, as well as U937 monocytes, the latter of which do not adhere at all to synthetic polymers used in tissue culture. In an effort to gain insight into cell adhesion mechanisms, we conducted a series of experiments where we cultured U937 monocytes on PP:N, as well as on two other families of chemically well-characterised N-rich thin films, the latter deposited by low pressure RF plasma and by vacuum ultra-violet (VUV) photo-polymerisation ("PVP:N" films). It was first shown that there exist sharply-defined ("critical") surface-chemical conditions that are necessary to induce cell adhesion. By comparing the extensively-characterised film chemistries at the " critical " conditions, we have clearly demonstrated the dominant role of primary amines in the cell adhesion mechanism. In the final aspect of this work, quantitative real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) experiments were conducted using U937 cells that had been made to adhere on PP:N and PVP:N materials for up to 24h. We have shown that the adhesion of U937 monocytes to PP:N and PVP:N surfaces induced a transient expression of cytokines, markers of macrophage activation, as well as a sustained expression of PPARgamma and ICAM-I, implicated in the adhesion and retention of monocytes. Keywords: biomaterials; dielectric barrier discharges (DBD); deposition; plasma polymerisation; ESCA/XPS; NEXAFS; FTIR; primary amines; cell adhesion; gene expression.

Comparative analysis of monocytic and granulocytic myeloid-derived suppressor cell subsets in patients with gastrointestinal malignancies.

PubMed

Duffy, Austin; Zhao, Fei; Haile, Lydia; Gamrekelashvili, Jaba; Fioravanti, Suzanne; Ma, Chi; Kapanadze, Tamar; Compton, Kathryn; Figg, William D; Greten, Tim F

2013-02-01

Myeloid-derived suppressor cells (MDSC) are a heterogenous population of cells comprising myeloid progenitor cells and immature myeloid cells, which have the ability to suppress the effector immune response. In humans, MDSC have not been well characterized owing to the lack of specific markers, although it is possible to broadly classify the MDSC phenotypes described in the literature as being predominantly granulocytic (expressing markers such as CD15, CD66, CD33) or monocytic (expressing CD14). In this study, we set out to perform a direct comparative analysis across both granulocytic and monocytic MDSC subsets in terms of their frequency, absolute number, and function in the peripheral blood of patients with advanced GI cancer. We also set out to determine the optimal method of sample processing given that this is an additional source of heterogeneity. Our findings demonstrate consistent changes across sample processing methods for monocytic MDSC, suggesting that reliance upon cryopreserved PBMC is acceptable. Although we did not see an increase in the population of granulocytic MDSC, these cells were found to be more suppressive than their monocytic counterparts.

CD14+CD16+ monocytes are the main target of Zika virus infection in peripheral blood mononuclear cells in a paediatric study in Nicaragua.

PubMed

Michlmayr, Daniela; Andrade, Paulina; Gonzalez, Karla; Balmaseda, Angel; Harris, Eva

2017-11-01

The recent Zika pandemic in the Americas is linked to congenital birth defects and Guillain-Barré syndrome. White blood cells (WBCs) play an important role in host immune responses early in arboviral infection. Infected WBCs can also function as 'Trojan horses' and carry viruses into immune-sheltered spaces, including the placenta, testes and brain. Therefore, defining which WBCs are permissive to Zika virus (ZIKV) is critical. Here, we analyse ZIKV infectivity of peripheral blood mononuclear cells (PBMCs) in vitro and from Nicaraguan Zika patients and show CD14 + CD16 + monocytes are the main target of infection, with ZIKV replication detected in some dendritic cells. The frequency of CD14 + monocytes was significantly decreased, while the CD14 + CD16 + monocyte population was significantly expanded during ZIKV infection compared to uninfected controls. Viral RNA was detected in PBMCs from all patients, but in serum from only a subset, suggesting PBMCs may be a reservoir for ZIKV. In Zika patients, the frequency of infected cells was lower but the percentage of infected CD14 + CD16 + monocytes was significantly higher compared to dengue cases. The gene expression profile in monocytes isolated from ZIKV- and dengue virus-infected patients was comparable, except for significant differences in interferon-γ, CXCL12, XCL1, interleukin-6 and interleukin-10 levels. Thus, our study provides a detailed picture of the innate immune profile of ZIKV infection and highlights the important role of monocytes, and CD14 + CD16 + monocytes in particular.

Identification of Human Cathelicidin Peptide LL-37 as a Ligand for Macrophage Integrin αMβ2 (Mac-1, CD11b/CD18) that Promotes Phagocytosis by Opsonizing Bacteria

PubMed Central

Lishko, Valeryi K.; Moreno, Benjamin; Podolnikova, Nataly P.; Ugarova, Tatiana P.

2016-01-01

LL-37, a cationic antimicrobial peptide, has numerous immune-modulating effects. However, the identity of a receptor(s) mediating the responses in immune cells remains uncertain. We have recently demonstrated that LL-37 interacts with the αMI-domain of integrin αMβ2 (Mac-1), a major receptor on the surface of myeloid cells, and induces a migratory response in Mac-1-expressing monocyte/macrophages as well as activation of Mac-1 on neutrophils. Here, we show that LL-37 and its C-terminal derivative supported strong adhesion of various Mac-1-expressing cells, including HEK293 cells stably transfected with Mac-1, human U937 monocytic cells and murine IC-21 macrophages. The cell adhesion to LL-37 was partially inhibited by specific Mac-1 antagonists, including mAb against the αM integrin subunit and neutrophil inhibitory factor, and completely blocked when anti-Mac-1 antibodies were combined with heparin, suggesting that cell surface heparan sulfate proteoglycans act cooperatively with integrin Mac-1. Coating both Gram-negative and Gram-positive bacteria with LL-37 significantly potentiated their phagocytosis by macrophages, and this process was blocked by a combination of anti-Mac-1 mAb and heparin. Furthermore, phagocytosis by wild-type murine peritoneal macrophages of LL-37-coated latex beads, a model of foreign surfaces, was several fold higher than that of untreated beads. By contrast, LL-37 failed to augment phagocytosis of beads by Mac-1-deficient macrophages. These results identify LL-37 as a novel ligand for integrin Mac-1 and demonstrate that the interaction between Mac-1 on macrophages and bacteria-bound LL-37 promotes phagocytosis. PMID:27990411

Dysregulation of in vitro cytokine production by monocytes during sepsis.

PubMed Central

Munoz, C; Carlet, J; Fitting, C; Misset, B; Blériot, J P; Cavaillon, J M

1991-01-01

The production by monocytes of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF alpha) in intensive care unit (ICU) patients with sepsis syndrome (n = 23) or noninfectious shock (n = 6) is reported. Plasma cytokines, cell-associated cytokines within freshly isolated monocytes and LPS-induced in vitro cytokine production were assessed at admission and at regular intervals during ICU stay. TNF alpha and IL-6 were the most frequently detected circulating cytokines. Despite the fact that IL-1 alpha is the main cytokine found within monocytes upon in vitro activation of cells from healthy individuals, it was very rarely detected within freshly isolated monocytes from septic patients, and levels of cell-associated IL-1 beta were lower than those of TNF alpha. Cell-associated IL-1 beta and TNF alpha were not correlated with corresponding levels in plasma. Upon LPS stimulation, we observed a profound decrease of in vitro IL-1 alpha production by monocytes in all patients, and of IL-1 beta, IL-6, and TNF alpha in septic patients. This reduced LPS-induced production of cytokines was most pronounced in patients with gram-negative infections. Finally, monocytes from survival patients, but not from nonsurvival ones recovered their capacity to produce normal amounts of cytokines upon LPS stimulation. In conclusion, our data indicate an in vivo activation of circulating monocytes during sepsis as well as in noninfectious shock and suggest that complex regulatory mechanisms can downregulate the production of cytokines by monocytes during severe infections. Images PMID:1939659

PAR(2) expression in peripheral blood monocytes of patients with rheumatoid arthritis.

PubMed

Crilly, A; Burns, E; Nickdel, M B; Lockhart, J C; Perry, M E; Ferrell, P W; Baxter, D; Dale, J; Dunning, L; Wilson, H; Nijjar, J S; Gracie, J A; Ferrell, W R; McInnes, I B

2012-06-01

Proteinase-activated receptor 2 (PAR(2)) is a G protein-coupled receptor activated by serine proteinases with proinflammatory activity. A study was undertaken to investigate the presence and functional significance of PAR(2) expression on rheumatoid arthritis (RA)-derived leucocyte subsets. Venous blood was obtained from patients with RA and osteoarthritis (OA) as well as healthy control subjects. Surface expression of PAR(2) on peripheral blood mononuclear cells (PBMCs) was analysed by flow cytometry and interleukin 6 (IL-6) generation by ELISA. Patients with RA had elevated but variable surface expression of PAR(2) on CD14+ monocytes compared with control subjects (median (1st to 3rd quartiles) 1.76% (0.86-4.10%) vs 0.06% (0.03-0.81%), p<0.0001). CD3+ T cells showed a similar pattern with significantly higher PAR(2) expression in patients with RA compared with controls (3.05% (0.36-11.82%) vs 0.08% (0.02-0.28%), p<0.0001). For both subsets, PAR(2) expression was significantly higher (p<0.00001) in patients with high levels of disease activity: PAR(2) expression for both CD14+ and CD3+ cells correlated to C reactive protein and erythrocyte sedimentation rate. Furthermore, in a cohort of patients with newly diagnosed RA, elevated PAR(2) expression in both CD14+ and CD3+ cells was significantly reduced 3 months after methotrexate or sulfasalazine treatment and this reduction correlated significantly with the reduction in the 28-joint Disease Activity Scale score (p<0.05). PAR(2) expression on cells from patients with OA was low, similar to levels seen in control subjects. Generation of IL-6 by monocytes in response to a selective PAR(2) agonist was significantly greater in patients with RA than in patients with OA and control subjects (p<0.05). These findings are consistent with a pathogenic role for PAR(2) in RA.

PAR2 expression in peripheral blood monocytes of patients with rheumatoid arthritis

PubMed Central

Crilly, A; Burns, E; Nickdel, M B; Lockhart, J C; Perry, M E; Ferrell, P W; Baxter, D; Dale, J; Dunning, L; Wilson, H; Nijjar, J S; Gracie, J A; Ferrell, W R; McInnes, I B

2012-01-01

Objectives Proteinase-activated receptor 2 (PAR2) is a G protein-coupled receptor activated by serine proteinases with proinflammatory activity. A study was undertaken to investigate the presence and functional significance of PAR2 expression on rheumatoid arthritis (RA)-derived leucocyte subsets. Methods Venous blood was obtained from patients with RA and osteoarthritis (OA) as well as healthy control subjects. Surface expression of PAR2 on peripheral blood mononuclear cells (PBMCs) was analysed by flow cytometry and interleukin 6 (IL-6) generation by ELISA. Results Patients with RA had elevated but variable surface expression of PAR2 on CD14+ monocytes compared with control subjects (median (1st to 3rd quartiles) 1.76% (0.86–4.10%) vs 0.06% (0.03–0.81%), p<0.0001). CD3+ T cells showed a similar pattern with significantly higher PAR2 expression in patients with RA compared with controls (3.05% (0.36–11.82%) vs 0.08% (0.02–0.28%), p<0.0001). For both subsets, PAR2 expression was significantly higher (p<0.00001) in patients with high levels of disease activity: PAR2 expression for both CD14+ and CD3+ cells correlated to C reactive protein and erythrocyte sedimentation rate. Furthermore, in a cohort of patients with newly diagnosed RA, elevated PAR2 expression in both CD14+ and CD3+ cells was significantly reduced 3 months after methotrexate or sulfasalazine treatment and this reduction correlated significantly with the reduction in the 28-joint Disease Activity Scale score (p<0.05). PAR2 expression on cells from patients with OA was low, similar to levels seen in control subjects. Generation of IL-6 by monocytes in response to a selective PAR2 agonist was significantly greater in patients with RA than in patients with OA and control subjects (p<0.05). Conclusions These findings are consistent with a pathogenic role for PAR2 in RA. PMID:22294633

Monocyte profile in peripheral blood of gestational diabetes mellitus patients.

PubMed

Angelo, Ana G S; Neves, Carla T C; Lobo, Thalita F; Godoy, Ramon V C; Ono, Érika; Mattar, Rosiane; Daher, Silvia

2018-07-01

Gestational diabetes Mellitus has been considered an inflammatory disease involving different cells and mediators in its development. The role of innate immune cells in GDM physiopathology remains unclear, therefore this study was conducted to assess monocyte profile in GDM patients. This was a case-control study including 20 glucose-tolerant pregnant women (controls) and 18 GDM patients. Flow cytometry was used to assess peripheral blood monocytes subsets (classical, intermediate, non-classical), the expression of TLR4 and CCR2 chemokine receptor (CD192) and cytokines (TNFA, IL6, IL10) secretion by monocytes subsets. In addition, sCD14 serum levels were evaluated by ELISA. We observed increased percentage of CD14 + cells, decreased frequency of intermediate monocytes (CD14 + CD16 + ), and lower percentage of circulating monocytes (classical, intermediate and non-classical) that express TLR4 in the diabetic group compared to controls. Soluble CD14 + serum levels were higher in GDM patients compared to controls. There were no differences in the expression of the CCR2 chemokine receptor and cytokines (TNFA, IL6 and IL10) secretion between the studied groups. Our results demonstrated that GDM patients present impaired monocyte profile in the peripheral blood, suggesting that these cells are involved in GDM physiopathology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Increase in Peripheral Blood Intermediate Monocytes is Associated with the Development of Recent-Onset Type 1 Diabetes Mellitus in Children.

PubMed

Ren, Xiaoya; Mou, Wenjun; Su, Chang; Chen, Xi; Zhang, Hui; Cao, Bingyan; Li, Xiaoqiao; Wu, Di; Ni, Xin; Gui, Jingang; Gong, Chunxiu

2017-01-01

Monocytes play important roles in antigen presentation and cytokine production to achieve a proper immune response, and are therefore largely implicated in the development and progression of autoimmune diseases. The aim of this study was to analyze the change in the intermediate (CD14+CD16+) monocyte subset in children with recent-onset type 1 diabetes mellitus (T1DM) and its possible association with clinical parameters reflecting islet β-cell dysfunction. Compared with age- and sex-matched healthy controls, intermediate monocytes were expanded in children with T1DM, which was positively associated with hemoglobin A1C and negatively associated with serum insulin and C-peptide. Interestingly, the intermediate monocytes in T1DM patients expressed higher levels of human leukocyte antigen-DR and CD86, suggesting better antigen presentation capability. Further analysis revealed that the frequency of CD45RO+CD4+ memory T cells was increased in the T1DM patients, and the memory T cell content was well correlated with the increase in intermediate monocytes. These results suggest that expanded intermediate monocytes are a predictive factor for the poor residual islet β-cell function in children with recent-onset T1DM.

Distinct Upstream Role of Type I IFN Signaling in Hematopoietic Stem Cell-Derived and Epithelial Resident Cells for Concerted Recruitment of Ly-6Chi Monocytes and NK Cells via CCL2-CCL3 Cascade

PubMed Central

Choi, Jin Young; Kim, Seong Bum; Eo, Seong Kug

2015-01-01

Type I interferon (IFN-I)-dependent orchestrated mobilization of innate cells in inflamed tissues is believed to play a critical role in controlling replication and CNS-invasion of herpes simplex virus (HSV). However, the crucial regulators and cell populations that are affected by IFN-I to establish the early environment of innate cells in HSV-infected mucosal tissues are largely unknown. Here, we found that IFN-I signaling promoted the differentiation of CCL2-producing Ly-6Chi monocytes and IFN-γ/granzyme B-producing NK cells, whereas deficiency of IFN-I signaling induced Ly-6Clo monocytes producing CXCL1 and CXCL2. More interestingly, recruitment of Ly-6Chi monocytes preceded that of NK cells with the levels peaked at 24 h post-infection in IFN-I–dependent manner, which was kinetically associated with the CCL2-CCL3 cascade response. Early Ly-6Chi monocyte recruitment was governed by CCL2 produced from hematopoietic stem cell (HSC)-derived leukocytes, whereas NK cell recruitment predominantly depended on CC chemokines produced by resident epithelial cells. Also, IFN-I signaling in HSC-derived leukocytes appeared to suppress Ly-6Ghi neutrophil recruitment to ameliorate immunopathology. Finally, tissue resident CD11bhiF4/80hi macrophages and CD11chiEpCAM+ dendritic cells appeared to produce initial CCL2 for migration-based self-amplification of early infiltrated Ly-6Chi monocytes upon stimulation by IFN-I produced from infected epithelial cells. Ultimately, these results decipher a detailed IFN-I–dependent pathway that establishes orchestrated mobilization of Ly-6Chi monocytes and NK cells through CCL2-CCL3 cascade response of HSC-derived leukocytes and epithelium-resident cells. Therefore, this cascade response of resident–to-hematopoietic–to-resident cells that drives cytokine–to-chemokine–to-cytokine production to recruit orchestrated innate cells is critical for attenuation of HSV replication in inflamed tissues. PMID:26618488

The effects of dietary fatty acids on the postprandial triglyceride-rich lipoprotein/apoB48 receptor axis in human monocyte/macrophage cells.

PubMed

Varela, Lourdes M; Ortega-Gomez, Almudena; Lopez, Sergio; Abia, Rocio; Muriana, Francisco J G; Bermudez, Beatriz

2013-12-01

Intestinally produced triglyceride-rich lipoproteins (TRL) play an important role in the progression of atherosclerosis. In this study, we investigated the relevance of monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) in postprandial TRL in affecting the transcriptional activity of the apolipoprotein-B48 receptor (ApoB48R) and its functionality in human monocyte/macrophage cells. Healthy male volunteers were administered four standardized high-fat meals containing butter, high-palmitic sunflower oil, olive oil (ROO) or a mixture of vegetable and fish oils (50 g/m(2) body surface area) to obtain a panel of postprandial TRL with gradual MUFA oleic acid-to-SFA palmitic acid ratios. The increase in this ratio was linearly associated with a decrease of ApoB48R up-regulation and lipid accumulation in THP-1 and primary monocytes. ApoB48R mRNA levels and intracellular triglycerides were also lower in the monocytes from volunteers after the ingestion of the ROO meal when compared to the ingestion of the butter meal. In THP-1 macrophages, the increase in the MUFA oleic acid-to-SFA palmitic acid ratio in the postprandial TRL was linearly correlated with an increase in ApoB48R down-regulation and a decrease in lipid accumulation. We also revealed that the nuclear receptor transcription factors PPARα, PPARβ/δ, and PPARγ and the PPAR-RXR transcriptional complex were involved in sensing the proportion of MUFA oleic acid and SFA palmitic acid, and these were also involved in adjusting the transcriptional activity of ApoB48R. The results of this study support the notion that MUFA-rich dietary fats may prevent excessive lipid accumulation in monocyte/macrophage cells by targeting the postprandial TRL/ApoB48R axis. © 2013.

The HIV-1 gp41 ectodomain is cleaved by matriptase to produce a chemotactic peptide that acts through FPR2

PubMed Central

Wood, Matthew P; Cole, Amy L; Eade, Colleen R; Chen, Li-Mei; Chai, Karl X; Cole, Alexander M

2014-01-01

Several aspects of HIV-1 virulence and pathogenesis are mediated by the envelope protein gp41. Additionally, peptides derived from the gp41 ectodomain have been shown to induce chemotaxis in monocytes and neutrophils. Whereas this chemotactic activity has been reported, it is not known how these peptides could be produced under biological conditions. The heptad repeat 1 (HR1) region of gp41 is exposed to the extracellular environment and could therefore be susceptible to proteolytic processing into smaller peptides. Matriptase is a serine protease expressed at the surface of most epithelia, including the prostate and mucosal surfaces. Here, we present evidence that matriptase efficiently cleaves the HR1 portion of gp41 into a 22-residue chemotactic peptide MAT-1, the sequence of which is highly conserved across HIV-1 clades. We found that MAT-1 induced migration of primary neutrophils and monocytes, the latter of which act as a cellular reservoir of HIV during early stage infection. We then used formyl peptide receptor 1 (FPR1) and FPR2 inhibitors, along with HEK 293 cells, to demonstrate that MAT-1 can induce chemotaxis specifically using FPR2, a receptor found on the surface of monocytes, macrophages and neutrophils. These findings are the first to identify a proteolytic cleavage product of gp41 with chemotactic activity and highlight a potential role for matriptase in HIV-1 transmission and infection at epithelial surfaces and within tissue reservoirs of HIV-1. PMID:24617769

Differential regulation of CD44 expression by lipopolysaccharide (LPS) and TNF-alpha in human monocytic cells: distinct involvement of c-Jun N-terminal kinase in LPS-induced CD44 expression.

PubMed

Gee, Katrina; Lim, Wilfred; Ma, Wei; Nandan, Devki; Diaz-Mitoma, Francisco; Kozlowski, Maya; Kumar, Ashok

2002-11-15

Alterations in the regulation of CD44 expression play a critical role in modulating cell adhesion, migration, and inflammation. LPS, a bacterial cell wall component, regulates CD44 expression and may modulate CD44-mediated biological effects in monocytic cells during inflammation and immune responses. In this study, we show that in normal human monocytes, LPS and LPS-induced cytokines IL-10 and TNF-alpha enhance CD44 expression. To delineate the mechanism underlying LPS-induced CD44 expression, we investigated the role of the mitogen-activated protein kinases (MAPKs), p38, p42/44 extracellular signal-regulated kinase, and c-Jun N-terminal kinase (JNK) by using their specific inhibitors. We demonstrate the involvement, at least in part, of p38 MAPK in TNF-alpha-induced CD44 expression in both monocytes and promonocytic THP-1 cells. However, neither p38 nor p42/44 MAPKs were involved in IL-10-induced CD44 expression in monocytes. To further dissect the TNF-alpha and LPS-induced signaling pathways regulating CD44 expression independent of IL-10-mediated effects, we used IL-10 refractory THP-1 cells as a model system. Herein, we show that CD44 expression induced by the LPS-mediated pathway predominantly involved JNK activation. This conclusion was based on results derived by transfection of THP-1 cells with a dominant-negative mutant of stress-activated protein/extracellular signal-regulated kinase kinase 1, and by exposure of cells to JNK inhibitors dexamethasone and SP600125. All these treatments prevented CD44 induction in LPS-stimulated, but not in TNF-alpha-stimulated, THP-1 cells. Furthermore, we show that CD44 induction may involve JNK-dependent early growth response gene activation in LPS-stimulated monocytic cells. Taken together, these results suggest a predominant role of JNK in LPS-induced CD44 expression in monocytic cells.

Myelodysplastic syndromes without peripheral monocytosis but with evidence of marrow monocytosis share clinical and molecular characteristics with CMML.

PubMed

Schuler, E; Frank, F; Hildebrandt, B; Betz, B; Strupp, C; Rudelius, M; Aul, C; Schroeder, T; Gattermann, N; Haas, R; Germing, U

2018-02-01

MDS patients may present with monocytic marrow proliferation not fulfilling criteria for CMML. We analyzed MDS patients with or without a marrow monocytic proliferation by following up the amount of monocytic proliferation and characterizing their molecular profile. 315 MDS patients of Duesseldorf MDS registry were divided into two groups: A) 183 patients with monocytic esterase positive cells in marrow and monocytes between 101 and 900/μl in blood and B) 132 patients without monocytic esterase positive cells in marrow and monocytes in blood ≤100/μl. Twenty patients of each group were screened with regard to ASXL1, TET2, RUNX1, SETBP1, NRAS, and SRSF2 using Illumina myeloid panel. Group A patients were older, had significantly higher WBC, hemoglobin levels, neutrophils and platelets. CMML evolution rates were 4.9% and 1.5%, respectively (p=n.s.). TET2, NRAS and SRFS2 mutation frequencies were higher in group A and four patients had coexisting TET2 and SRFS2 mutation, which was shown to be characteristic but not specific for CMML. MDS patients with marrow monocytic proliferation have a more CMML-like pheno- and genotype and develop CMML more often. Those patients could potentially be very early stages of CMML or represent a CMML-like myeloid neoplasma with marrow adherence of the monocytic cell population. Copyright © 2017 Elsevier Ltd. All rights reserved.

ASGR1 and ASGR2, the Genes that Encode the Asialoglycoprotein Receptor (Ashwell Receptor), Are Expressed in Peripheral Blood Monocytes and Show Interindividual Differences in Transcript Profile

PubMed Central

Harris, Rebecca Louise; van den Berg, Carmen Wilma; Bowen, Derrick John

2012-01-01

Background. The asialoglycoprotein receptor (ASGPR) is a hepatic receptor that mediates removal of potentially hazardous glycoconjugates from blood in health and disease. The receptor comprises two proteins, asialoglycoprotein receptor 1 and 2 (ASGR1 and ASGR2), encoded by the genes ASGR1 and ASGR2. Design and Methods. Using reverse transcription amplification (RT-PCR), expression of ASGR1 and ASGR2 was investigated in human peripheral blood monocytes. Results. Monocytes were found to express ASGR1 and ASGR2 transcripts. Correctly spliced transcript variants encoding different isoforms of ASGR1 and ASGR2 were present in monocytes. The profile of transcript variants from both ASGR1 and ASGR2 differed among individuals. Transcript expression levels were compared with the hepatocyte cell line HepG2 which produces high levels of ASGPR. Monocyte transcripts were 4 to 6 orders of magnitude less than in HepG2 but nonetheless readily detectable using standard RT-PCR. The monocyte cell line THP1 gave similar results to monocytes harvested from peripheral blood, indicating it may provide a suitable model system for studying ASGPR function in this cell type. Conclusions. Monocytes transcribe and correctly process transcripts encoding the constituent proteins of the ASGPR. Monocytes may therefore represent a mobile pool of the receptor, capable of reaching sites remote from the liver. PMID:22919488

The CD14+CD16+ Inflammatory Monocyte Subset Displays Increased Mitochondrial Activity and Effector Function During Acute Plasmodium vivax Malaria

PubMed Central

Antonelli, Lis R. V.; Leoratti, Fabiana M. S.; Costa, Pedro A. C.; Rocha, Bruno C.; Diniz, Suelen Q.; Tada, Mauro S.; Pereira, Dhelio B.; Teixeira-Carvalho, Andrea; Golenbock, Douglas T.; Gonçalves, Ricardo; Gazzinelli, Ricardo T.

2014-01-01

Infection with Plasmodium vivax results in strong activation of monocytes, which are important components of both the systemic inflammatory response and parasite control. The overall goal of this study was to define the role of monocytes during P. vivax malaria. Here, we demonstrate that P. vivax–infected patients display significant increase in circulating monocytes, which were defined as CD14+CD16− (classical), CD14+CD16+ (inflammatory), and CD14loCD16+ (patrolling) cells. While the classical and inflammatory monocytes were found to be the primary source of pro-inflammatory cytokines, the CD16+ cells, in particular the CD14+CD16+ monocytes, expressed the highest levels of activation markers, which included chemokine receptors and adhesion molecules. Morphologically, CD14+ were distinguished from CD14lo monocytes by displaying larger and more active mitochondria. CD14+CD16+ monocytes were more efficient in phagocytizing P. vivax-infected reticulocytes, which induced them to produce high levels of intracellular TNF-α and reactive oxygen species. Importantly, antibodies specific for ICAM-1, PECAM-1 or LFA-1 efficiently blocked the phagocytosis of infected reticulocytes by monocytes. Hence, our results provide key information on the mechanism by which CD14+CD16+ cells control parasite burden, supporting the hypothesis that they play a role in resistance to P. vivax infection. PMID:25233271

Nanovectors for Targeting and Delivery of Therapeutics to HER-2 NEU Positive Breast Cancer Cells

DTIC Science & Technology

2008-10-01

Staphylococcus aureus induces hyperadhesiveness for human monocytes and granulocytes. J.Immunol. 158 (1997) 774-782. [19] Ibrahim, A. S., Spellberg, B...antibodies (or aptamers ) attached to the first stage of the delivery vector. Markers with increased expression on the surface of tumor cells, such as...with second-stage iron oxide nanoparticles. As stated previously, HER2-conjugated iron oxide nanoparticles and VEGFR-2 antibody (or aptamer

STATUS OF THE SYSTEM OF SIGNALING PATTERN RECOGNITION RECEPTORS OF MONOCYTES AND GRANULOCYTES IN COSMONAUTS' PERIPHERAL BLOOD BEFORE AND AFTER LONG-DURATION MISSIONS TO THE INTERNATIONAL SPACE STATION.

PubMed

Ponomarev, S A; Berendeeva, T A; Kalinin, S A; Muranova, A V

The system of signaling pattern recognition receptors was studied in 8 cosmonauts aged 35 to 56 years before and after (R+) long-duration missions to the International space station. Peripheral blood samples were analyzed for the content of monocytes and granulocytes that express the signaling pattern recognition Toll- like (TLR) receptors localized as on cell surface (TLR1, TLR2, TLR4, TLR5, TLR6), so inside cells (TLR3, TLR8, TLR9). In parallel, serum concentrations of TLR2 (HSP60) and TLR4 ligands (HSP70, HMGB1) were measured. The results of investigations showed growth of HSP60, HSP70 and HMGB1 concentrations on R+1. In the;majority of cosmonauts increases in endogenous ligands were followed by growth in the number of both monocytes and granulocytes that express TLR2 1 TLR4. This consistency gives ground to assume that changes in the system of signaling pattern recognition receptors can stem .from the predominantly endogenous ligands' response to the effects of long-duration space flight on human organism.

EMMPRIN (CD147) is induced by C/EBPβ and is differentially expressed in ALK+ and ALK- anaplastic large-cell lymphoma.

PubMed

Schmidt, Janine; Bonzheim, Irina; Steinhilber, Julia; Montes-Mojarro, Ivonne A; Ortiz-Hidalgo, Carlos; Klapper, Wolfram; Fend, Falko; Quintanilla-Martínez, Leticia

2017-09-01

Anaplastic lymphoma kinase-positive (ALK+) anaplastic large-cell lymphoma (ALCL) is characterized by expression of oncogenic ALK fusion proteins due to the translocation t(2;5)(p23;q35) or variants. Although genotypically a T-cell lymphoma, ALK+ ALCL cells frequently show loss of T-cell-specific surface antigens and expression of monocytic markers. C/EBPβ, a transcription factor constitutively overexpressed in ALK+ ALCL cells, has been shown to play an important role in the activation and differentiation of macrophages and is furthermore capable of transdifferentiating B-cell and T-cell progenitors to macrophages in vitro. To analyze the role of C/EBPβ for the unusual phenotype of ALK+ ALCL cells, C/EBPβ was knocked down by RNA interference in two ALK+ ALCL cell lines, and surface antigen expression profiles of these cell lines were generated using a Human Cell Surface Marker Screening Panel (BD Biosciences). Interesting candidate antigens were further analyzed by immunohistochemistry in primary ALCL ALK+ and ALK- cases. Antigen expression profiling revealed marked changes in the expression of the activation markers CD25, CD30, CD98, CD147, and CD227 after C/EBPβ knockdown. Immunohistochemical analysis confirmed a strong, membranous CD147 (EMMPRIN) expression in ALK+ ALCL cases. In contrast, ALK- ALCL cases showed a weaker CD147 expression. CD274 or PD-L1, an immune inhibitory receptor ligand, was downregulated after C/EBPβ knockdown. PD-L1 also showed stronger expression in ALK+ ALCL compared with ALK- ALCL, suggesting an additional role of C/EBPβ in ALK+ ALCL in generating an immunosuppressive environment. Finally, no expression changes of T-cell or monocytic markers were detected. In conclusion, surface antigen expression profiling demonstrates that C/EBPβ plays a critical role in the activation state of ALK+ ALCL cells and reveals CD147 and PD-L1 as important downstream targets. The multiple roles of CD147 in migration, adhesion, and invasion, as well as T-cell activation and proliferation suggest its involvement in the pathogenesis of ALCL.

Type of monocyte immunomagnetic separation affects the morphology of monocyte-derived dendritic cells, as investigated by scanning electron microscopy.

PubMed

Kowalewicz-Kulbat, M; Ograczyk, E; Krawczyk, K; Rudnicka, W; Fol, M

2016-12-01

Dendritic cells (DCs) are increasingly being used for multiple applications and are useful tools for many immunotherapeutic strategies. The understanding of the possible impact of the DCs-generation methods on the biological capacities of these cells is therefore essential. Although the immunomagnetic separation is regarded as a fast and accurate method yielding cells with the high purity and efficiency, still little is known about its impact on the properties of the generated DCs. The aim of this study was to compare the morphology of the monocyte derived dendritic cells (MoDCs), generated from monocytes selected with anti-CD14 mAbs (positive separation) and treated with anti-CD3, -CD7, -CD16, -CD19, -CD56, -CD123, glycophorin A (negative separation), using laser scanning microscopy. We found that the type of the immunomagnetic separation method used strongly influences the shape and cell dimension of the MoDCs. We observed that the height of both immature and LPS-matured DCs generated from monocytes isolated by negative separation was significantly higher compared to the cells obtained by positive separation. Copyright © 2016 Elsevier B.V. All rights reserved.

CD1 molecule expression on human monocytes induced by granulocyte-macrophage colony-stimulating factor.

PubMed

Kasinrerk, W; Baumruker, T; Majdic, O; Knapp, W; Stockinger, H

1993-01-15

In this paper we demonstrate that granulocyte-macrophage CSF (GM-CSF) specifically induces the expression of CD1 molecules, CD1a, CD1b and CD1c, upon human monocytes. CD1 molecules appeared upon monocytes on day 1 of stimulation with rGM-CSF, and expression was up-regulated until day 3. Monocytes cultured in the presence of LPS, FMLP, PMA, recombinant granulocyte-CSF, rIFN-gamma, rTNF-alpha, rIL-1 alpha, rIL-1 beta, and rIL-6 remained negative. The induction of CD1 molecules by rGM-CSF was restricted to monocytes, since no such effect was observed upon peripheral blood granulocytes, PBL, and the myeloid cell lines Monomac1, Monomac6, MV4/11, HL60, U937, THP1, KG1, and KG1A. CD1a mRNA was detectable in rGM-CSF-induced monocytes but not in those freshly isolated. SDS-PAGE and immunoblotting analyses of CD1a mAb VIT6 immunoprecipitate from lysate of rGM-CSF-activated monocytes revealed an appropriate CD1a polypeptide band of 49 kDa associated with beta 2-microglobulin. Expression of CD1 molecules on monocytes complements the distribution of these structures on accessory cells, and their specific induction by GM-CSF strengthens the suggestion that CD1 is a family of crucial structures required for interaction between accessory cells and T cells.

AGEs and HMGB1 Increase Inflammatory Cytokine Production from Human Placental Cells, Resulting in an Enhancement of Monocyte Migration.

PubMed

Shirasuna, Koumei; Seno, Kotomi; Ohtsu, Ayaka; Shiratsuki, Shogo; Ohkuchi, Akihide; Suzuki, Hirotada; Matsubara, Shigeki; Nagayama, Shiho; Iwata, Hisataka; Kuwayama, Takehito

2016-05-01

Advanced glycation end products (AGEs) and high-mobility group box-1 (HMGB1) are considered contributing to placental inflammation. We examined the effect of AGEs and HMGB1 on cytokines from Sw.71 human trophoblast cell lines and the interactions between Sw.71 cells and THP-1-monocytes. Sw.71 cells were cultured with/without AGEs or HMGB1. We examined the role of AGEs or HMGB1 on THP1 migration and effect of AGEs on IL-6 from Sw.71 cells using co-cultures or conditioned medium from THP-1 cells. AGEs and HMGB1 increased interleukin (IL)-6, IL-8, and chemokine C-C motif ligand 2 (CCL2) secretion from Sw.71 cells. The secretion of IL-6 was dependent on reactive oxygen species (ROS) and NF-κB. AGEs stimulated IL-6 secretion through receptor RAGE and TLR4, whereas HMGB1 stimulated it through TLR4. AGEs, but not HMGB1, increased monocyte migration via IL-8 and CCL2 from Sw.71 cells. THP-1 monocytes induced IL-6 secretion from Sw.71 cells, and AGEs further stimulated it. AGEs and HMGB1 may promote sterile placental inflammation cooperating with monocytes/macrophages. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Environmentally relevant dose of arsenic interferes in functions of human monocytes derived dendritic cells.

PubMed

Bahari, Abbas; Salmani, Vahid

2017-06-05

Arsenic is a major environmental pollutant and highly hazardous toxin to human health, which well established as carcinogen and immune deregulatory properties. Dendritic cells (DCs) have a pivotal role in cell-mediated immunity for T-cell activation and antigen presentation. In this study, T cell activation, some key functional genes expression, cell stability and phagocytosis capacity of human monocytes derived DCs (MDDCs) were analyzed after in vitro exposure to very low dose of arsenic for 12 and 24h. Arsenic decreased continually phagocytosis capacity of MDDCs. Furthermore, down-regulation of the cell-surface expression of the co-stimulatory molecule CD40 after 24h post treatment with arsenic, confirmed arsenic interferers in the phagocytosis process. Pro inflammatory cytokines, IL1β and TNFα were more expressed in arsenic-treated MDDCs while IL6 transiently was down regulated. In general, our novel findings here strongly suggest that low level of arsenic dysregulates four fundamental immune processes of DCs. Mechanistically; this could explain the observed immunodeficiency activity of Arsenic, and give direction for comprehension the pathogenesis of Arsenic-induced diseases. Copyright © 2017. Published by Elsevier B.V.

Lack of autologous mixed lymphocyte reaction in patients with chronic lymphocytic leukemia: evidence for autoreactive T-cell dysfunction not correlated with phenotype, karyotype, or clinical status

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, T.; Bloom, M.L.; Dadey, B.

In the present study, there was a complete lack of autologous MLR between responding T cells or T subsets and unirradiated or irradiated leukemic B cells or monocytes in all 20 patients with CLL, regardless of disease status, stage, phenotype, or karyotype of the disease. The stimulating capacity of unirradiated CLL B cells and CLL monocytes or irradiated CLL B cells was significantly depressed as compared to that of respective normal B cells and monocytes in allogeneic MLR. The responding capacity of CLL T cells was also variably lower than that of normal T cells against unirradiated or irradiated normalmore » allogeneic B cells and monocytes. The depressed allogeneic MLR between CLL B cells or CLL monocytes and normal T cells described in the present study could be explained on the basis of a defect in the stimulating antigens of leukemic B cells or monocytes. The decreased allogeneic MLR of CLL T cells might simply be explained by a defect in the responsiveness of T lymphocytes from patients with CLL. However, these speculations do not adequately explain the complete lack of autologous MLR in these patients. When irradiated CLL B cells or irradiated CLL T cells were cocultured with normal T cells and irradiated normal B cells, it was found that there was no suppressor cell activity of CLL B cells or CLL T cells on normal autologous MLR. Our data suggest that the absence or dysfunction of autoreactive T cells within the Tnon-gamma subset account for the lack of autologous MLR in patients with CLL. The possible significance of the autologous MLR, its relationship to in vivo immunoregulatory mechanisms, and the possible role of breakdown of autoimmunoregulation in the oncogenic process of certain lymphoproliferative and autoimmune diseases in man are discussed.« less

Differential Interaction of Platelet-Derived Extracellular Vesicles with Leukocyte Subsets in Human Whole Blood.

PubMed

Weiss, René; Gröger, Marion; Rauscher, Sabine; Fendl, Birgit; Eichhorn, Tanja; Fischer, Michael B; Spittler, Andreas; Weber, Viktoria

2018-04-26

Secretion and exchange of biomolecules via extracellular vesicles (EVs) are crucial mechanisms in intercellular communication, and the roles of EVs in infection, inflammation, or thrombosis have been increasingly recognized. EVs have emerged as central players in immune regulation and can enhance or suppress the immune response, depending on the state of donor and recipient cells. We investigated the interaction of blood cell-derived EVs with leukocyte subpopulations (monocytes and their subsets, granulocytes, B cells, T cells, and NK cells) directly in whole blood using a combination of flow cytometry, imaging flow cytometry, cell sorting, and high resolution confocal microscopy. Platelet-derived EVs constituted the majority of circulating EVs and were preferentially associated with granulocytes and monocytes, while they scarcely interacted with lymphocytes. Further flow cytometric differentiation of monocyte subsets provided clear indications for a preferential association of platelet-derived EVs with intermediate (CD14 ++ CD16 + ) monocytes in whole blood.

Evaluating the Use of Monocytes with a Degradable Polyurethane for Vascular Tissue Regeneration

NASA Astrophysics Data System (ADS)

Battiston, Kyle Giovanni

Monocytes are one of the first cell types present following the implantation of a biomaterial or tissue engineered construct. Depending on the monocyte activation state supported by the biomaterial, monocytes and their derived macrophages (MDMs) can act as positive contributors to tissue regeneration and wound healing, or conversely promote a chronic inflammatory response that leads to fibrous encapsulation and implant rejection. A degradable polar hydrophobic iconic polyurethane (D-PHI) has been shown to reduce pro-inflammatory monocyte/macrophage response compared to tissue culture polystyrene (TCPS), a substrate routinely used for in vitro culture of cells, as well as poly(lactide- co-glycolide) (PLGA), a standard synthetic biodegradable biomaterial in the tissue engineering field. D-PHI has also shown properties suitable for use in a vascular tissue engineering context. In order to understand the mechanism through which D-PHI attenuates pro-inflammatory monocyte response, this thesis investigated the ability of D-PHI to modulate interactions with adsorbed serum proteins and the properties of D-PHI that were important for this activity. D-PHI was shown to regulate protein adsorption in a manner that produced divergent monocyte responses compared to TCPS and PLGA when coated with the serum proteins alpha2-macroglobulin or immunoglobulin G (IgG). In the case of IgG, D-PHI was shown to reduce pro-inflammatory binding site exposure as a function of the material's polar, hydrophobic, and ionic character. Due to the favourable monocyte activation state supported by D-PHI, and the importance of monocytes/macrophages in regulating the response of tissue-specific cell types in vivo, the ability of a D-PHI-stimulated monocyte/macrophage activation state to contribute to modulating the response of vascular smooth muscle cells (VSMCs) in a vascular tissue engineering context was investigated. D-PHI- stimulated monocytes promoted VSMC growth and migration through biomolecule release. Coupling monocyte-VSMC co-culture with biomechanical strain further enhanced these effects, while also promoting extracellular matrix deposition (collagen I, collagen III, and elastin) and enhancing the mechanical properties of VSMC-monocyte seeded tissue constructs. This thesis identifies the use of biomaterials with immunomodulatory capacity to harness the stimulatory potential of MDMs and contribute to tissue engineering strategies in vitro. This latter work in turn has contributed to identifying aspects of biomaterial design that can contribute to supporting desirable monocyte-biomaterial interactions that can facilitate this process.

The induction of monocytopoiesis in HL-60 promyelocytic leukemia cells is inhibited by hydroquinone, a toxic metabolite of benzene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, N.L.

1992-01-01

Chronic exposure of humans to benzene has been shown to have a cytotoxic effect on hematopoietic progenitor cells in intermediate stages of differentiation which can lead to aplastic anemia and acute myelogenous leukemia. This thesis examined the effect of hydroquinone, a toxic metabolite of benzene found in the bone marrow, on the human promyelocytic leukemia cell line (HL-60) which can be induced to differentiate to both monocyte and myeloid cells, and thus has been used as a surrogate for a granulocyte/macrophage progenitor cell. Exposure of HL-60 cells to noncytotoxic concentrations of hydroquinone for three hours prior to induction with 12-O-tetradecanoylmore » phorbol-13-acetate caused a dose-dependent inhibition of the acquisition of characteristics of monocytic differentiation. These included adherence, nonspecific esterase activity and phagocytosis. Hydroquinone had no effect on cell proliferation. Hydroquinone appeared to be affecting maturation beyond the monoblast/promonocyte stages. Hydroquinone also prevented differentiation induced by 1, 25-dihydroxy vitamin D[sub 3], however, the block occurred after the acquisition of adherence. Hydroquinone at concentrations that inhibited monocytic differentiation had no effect on differentiation to granulocytes, suggesting that the block in the differentiation of these bipotential cells is at a step unique to the monocytic pathway. Hydroquinone was unable to prevent differentiation induced by the macrophage-derived cytokine interleukin-1, a differentiation factor for cells of the monocytic lineage. These data demonstrate that treatment of Hl-60 cells with hydroquinone prior to induction of differentiation prevents the acquisition of the monocytic phenotype induced by TPA or 1, 25(OH)[sub 2]D[sub 3] by a mechanism which at present is unknown, but which appears to be specific for the monocytic pathway. These results are of considerable significance for benzene hematotoxicity.« less

Monocyte recruitment to endothelial cells in response to oscillatory shear stress

PubMed Central

Hsiai, Tzung K.; Cho, Sung K.; Wong, Pak K.; Ing, Mike; Salazar, Adler; Sevanian, Alex; Navab, Mohamad; Demer, Linda L.; Ho, Chih-Ming

2014-01-01

Leukocyte recruitment to endothelial cells is a critical event in inflammatory responses. The spatial, temporal gradients of shear stress, topology, and outcome of cellular interactions that underlie these responses have so far been inferred from static imaging of tissue sections or studies of statically cultured cells. In this report, we developed micro-electromechanical systems (MEMS) sensors, comparable to a single endothelial cell (EC) in size, to link real-time shear stress with monocyte/EC binding kinetics in a complex flow environment, simulating the moving and unsteady separation point at the arterial bifurcation with high spatial and temporal resolution. In response to oscillatory shear stress (τ) at ± 2.6 dyn/cm2 at a time-averaged shear stress (τave) = 0 and 0.5 Hz, individual monocytes displayed unique to-and-fro trajectories undergoing rolling, binding, and dissociation with other monocyte, followed by solid adhesion on EC. Our study quantified individual monocyte/EC binding kinetics in terms of displacement and velocity profiles. Oscillatory flow induces up-regulation of adhesion molecules and cytokines to mediate monocyte/EC interactions over a dynamic range of shear stress ± 2.6 dyn/cm2 (P= 0.50, n= 10).—Hsiai, T. K., Cho, S. K., Wong, P. K., Ing, M., Salazar, A., Sevanian, A., Navab, M., Demer, L. L., Ho, C.-M. Monocyte recruitment to endothelial cells in response to oscillatory shear stress. FASEB J. 17, 1648–1657 (2003) PMID:12958171

Myeloid-derived suppressor cells can be efficiently generated from human hematopoietic progenitors and peripheral blood monocytes.

PubMed

Casacuberta-Serra, Sílvia; Parés, Marta; Golbano, Arantxa; Coves, Elisabet; Espejo, Carmen; Barquinero, Jordi

2017-07-01

Myeloid-derived suppressor cells (MDSCs) have an important role in controlling inflammation. As such, they are both a therapeutic target and, based on the administration of ex vivo-generated MDSCs, a therapeutic tool. However, there are relatively few reports describing methods to generate human MDSCs, and most of them rely on cells obtained from peripheral blood monocytes. We investigated alternative approaches to the generation of MDSCs from hematopoietic progenitors and monocytes. Purified CD34 + hematopoietic progenitors from apheresis products and CD14 + cells isolated from buffy coats were cultured in the presence of different combinations of cytokines. The resulting myeloid cell populations were then characterized phenotypically and functionally. Progenitor cells cultured in the presence of SCF+TPO+FLT3-L+GM-CSF+IL-6 gave rise to both monocytic (M)- and granulocytic (G)-MDSCs but production of the latter was partially inhibited by IL-3. M-MDSCs but not G-MDSCs were obtained by culturing peripheral blood monocytes with GM-CSF+IL-6 or GM-CSF+TGF-β1 for 6 days. CD14 expression was downregulated in the cultured cells. PD-L1 expression at baseline was lower in hematopoietic progenitor cell-derived than in monocyte-derived MDSCs, but was markedly increased in response to stimulation with LPS+IFN-γ. The functionality of the two MDSC subtypes was confirmed in studies of the suppression of allogeneic and mitogen-induced proliferation and by cytokine profiling. Here we describe both the culture conditions that allow the generation of MDSCs and the phenotypical and functional characterization of these cell populations.

Dendritic Cells and Innate Immunity in Kidney Transplantation

PubMed Central

Zhuang, Quan; Lakkis, Fadi G.

2015-01-01

Summary This review summarizes emerging concepts related to the roles of dendritic cells and innate immunity in organ transplant rejection. First, it highlights the primary role that recipient, rather than donor, dendritic cells have in rejection and reviews their origin and function in the transplanted kidney. Second, it introduces the novel concept that recognition of allogeneic non-self by host monocytes (referred to here as innate allorecognition) is necessary for initiating rejection by inducing monocyte differentiation into mature, antigen-presenting dendritic cells. Both concepts provide opportunities for preventing rejection by targeting monocytes or dendritic cells. PMID:25629552

Couches minces organiques riches en amines primaires par photo-polymerisation ultraviolette : Caracterisation et applications biomedicales

NASA Astrophysics Data System (ADS)

St-Georges-Robillard, Amelie

Biomaterials have evolved significantly over the past decades. There are now several types of polymeric biomaterials with physical characteristics suited to different applications. This project focuses on improving the physico-chemical properties of the surface of these materials by incorporating primary amines (R-NH2), a functional group known to promote adhesion and cell growth, in the context of two biomedical applications. First, it is necessary to develop a cell culture surface that enables the adhesion of U937 monocytes. These cells are used to evaluate the effect of wear particles produced by the prosthesis in periprosthetic osteolysis, a major cause of failure of a hip replacement. Second, one of the strategies used to improve the success rate of polymeric vascular grafts is to create a layer of endothelial cells on the lumen of the prosthesis. A coating that promotes the adhesion and growth of human umbilical vein endothelial cells (HUVEC) is required to achieve that layer. Previous studies have demonstrated that the addition of R-NH2 groups on the coating allows the adhesion of U937 monocytes, provided that their concentration [NH2] is higher than a certain critical value, [NH2]crit; R-NH2 groups were also found to enhance the adhesion and proliferation of HUVEC. Two different primary amine-rich coatings are investigated in this work: organic thin films deposited by vacuum ultraviolet (VUV) photo-polymerization, UV-PE:N; and parylene diX AM, deposited by chemical vapor deposition (CVD). The physico-chemical stability of these coatings in air and in water, essential for biomedical applications, was first studied. “Aging” of parylene diX AM in contact with the ambient air caused a diminution of [NH2]/[C] of around 6 % during 22 days and is caused by the oxidation of R-NH2 by atmospheric oxygen, while in the case of UV-PE:N, the diminution is only of 2,5 % over 26 days. Also, a second aging mechanism is present: the reaction of trapped free radicals in the coating with oxygen in air or dissolved in water. The UV-PE:N coating proved virtually insoluble, despite a high concentration of nitrogen and showed excellent retention of the R-NH 2 groups when immersed in water, two essential properties for applications in cell culture. These studies have also shown that UV-PE:N coatings (deposited with two gas ratios, R = 0.75 and 1) permit adhesion and survival of U937 monocytes without causing any significant inflammatory response, which enables one to study wear particle effects. However, the adhesion of U937 monocytes on parylene diX AM manifests a rather different behavior, adhesion being proportional to [NH2] and not controlled by the critical threshold, [NH 2]crit, observed for different types of plasma-polymer coatings. Also, monocytes do not survive for 24 hours on parylene diX AM. The cause for these differences remains to be elucidated. Finally, the adhesion and growth of HUVEC on both types of UV-PE:N (R = 0.75 and 1), as well as on L-PPE:N and on gelatinized polystyrene, were statistically higher than on untreated PET. Therefore, UV-PE:N has proven to be a cell culture surface well-adapted for HUVEC, of similar efficiency to gelatinized polystyrene, a surface known to promote the adhesion and growth of HUVEC. UV-PE: N is therefore a promising coating that provides stability in air and in water for use in cell culture and has demonstrated its performance for two biomedical applications. Keywords: biomaterials, primary amines, thin film deposition, photo-polymerization, plasma polymerization, XPS, chemical derivatization, ellipsometry, cellular adhesion, arthroplasty, vascular graft.

PKC-Dependent Human Monocyte Adhesion Requires AMPK and Syk Activation

PubMed Central

Chang, Mei-Ying; Huang, Duen-Yi; Ho, Feng-Ming; Huang, Kuo-Chin; Lin, Wan-Wan

2012-01-01

PKC plays a pivotal role in mediating monocyte adhesion; however, the underlying mechanisms of PKC-mediated cell adhesion are still unclear. In this study, we elucidated the signaling network of phorbol ester PMA-stimulated human monocyte adhesion. Our results with pharmacological inhibitors suggested the involvement of AMPK, Syk, Src and ERK in PKC-dependent adhesion of THP-1 monocytes to culture plates. Biochemical analysis further confirmed the ability of PMA to activate these kinases, as well as the involvement of AMPK-Syk-Src signaling in this event. Direct protein interaction between AMPK and Syk, which requires the kinase domain of AMPK and linker region of Syk, was observed following PMA stimulation. Notably, we identified Syk as a novel downstream target of AMPK; AICAR can induce Syk phosphorylation at Ser178 and activation of this kinase. However, activation of AMPK alone, either by stimulation with AICAR or by overexpression, is not sufficient to induce monocyte adhesion. Studies further demonstrated that PKC-mediated ERK signaling independent of AMPK activation is also involved in cell adhesion. Moreover, AMPK, Syk, Src and ERK signaling were also required for PMA to induce THP-1 cell adhesion to endothelial cells as well as to induce adhesion response of human primary monocytes. Taken together, we propose a bifurcated kinase signaling pathway involved in PMA-mediated adhesion of monocytes. PKC can activate LKB1/AMPK, leading to phosphorylation and activation of Syk, and subsequent activation of Src and FAK. In addition, PKC-dependent ERK activation induces a coordinated signal for cytoskeleton rearrangement and cell adhesion. For the first time we demonstrate Syk as a novel substrate target of AMPK, and shed new light on the role of AMPK in monocyte adhesion, in addition to its well identified functions in energy homeostasis. PMID:22848421

CD40 ligation and phagocytosis differently affect the differentiation of monocytes into dendritic cells.

PubMed

Rosenzwajg, Michelle; Jourquin, Frédéric; Tailleux, Ludovic; Gluckman, Jean Claude

2002-12-01

That monocytes can differentiate into macrophages or dendritic cells (DCs) makes them an essential link between innate and adaptive immunity. However, little is known about how interactions with pathogens or T cells influence monocyte engagement toward DCs. We approached this point in cultures where granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4 induced monocytes to differentiate into immature DCs. Activating monocytes with soluble CD40 ligand (CD40L) led to accelerated differentiation toward mature CD83(+) DCs with up-regulated human leukocyte antigen-DR, costimulatory molecules and CD116 (GM-CSF receptor), and down-regulation of molecules involved in antigen capture. Monocytes primed by phagocytosis of antibody-opsonized, killed Escherichia coli differentiated into DCs with an immature phenotype, whereas Zymosan priming yielded active DCs with an intermediate phenotype. Accordingly, DCs obtained from cultures with CD40L or after Zymosan priming had a decreased capacity to endocytose dextran, but only DCs cultured with CD40L had increased capacity to stimulate allogeneic T cells. DCs obtained after E. coli or Zymosan priming of monocytes produced high levels of proinflammatory tumor necrosis factor alpha and IL-6 as well as of regulatory IL-10, but they produced IL-12p70 only after secondary CD40 ligation. Thus, CD40 ligation on monocytes accelerates the maturation of DCs in the presence of GM-CSF/IL-4, whereas phagocytosis of different microorganisms does not alter and even facilitates their potential to differentiate into immature or active DCs, the maturation of which can be completed upon CD40 ligation. In vivo, such differences may correspond to DCs with different trafficking and T helper cell-stimulating capacities that could differently affect induction of adaptive immune responses to infections.

Upregulation of Monocyte/Macrophage HGFIN (Gpnmb/Osteoactivin) Expression in End-Stage Renal Disease

PubMed Central

Vaziri, Nosratola D.; Yuan, Jun; Adler, Sharon G.

2010-01-01

Background and objectives: Hematopoietic growth factor–inducible neurokinin 1 (HGFIN), also known as Gpnmb and osteoactivin, is a transmembrane glycoprotein that is expressed in numerous cells, including osteoclasts, macrophages, and dendritic cells. It serves as an osteoblast differentiation factor, participates in bone mineralization, and functions as a negative regulator of inflammation in macrophages. Although measurable at low levels in monocytes, monocyte-to-macrophage transformation causes substantial increase in HGFIN expression. HGFIN is involved in systemic inflammation, bone demineralization, and soft tissue vascular calcification. Design, setting, participants, & measurements: We explored HGFIN expression in monocytes and monocyte-derived macrophages in 21 stable hemodialysis patients and 22 control subjects. Results: Dialysis patients exhibited marked upregulation of colony-stimulating factor and IL-6 and significant downregulation of IL-10 in intact monocytes and transformed macrophages. HGFIN expression in intact monocytes was negligible in control subjects but conspicuously elevated (8.6-fold) in dialysis patients. As expected, in vitro monocyte-to-macrophage transformation resulted in marked upregulation of HGFIN in cells obtained from both groups but much more so in dialysis patients (17.5-fold higher). Upregulation of HGFIN and inflammatory cytokines in the uremic monocyte-derived macrophages occurred when grown in the presence of either normal or uremic serum, suggesting the enduring effect of the in vivo uremic milieu on monocyte/macrophage phenotype and function. Conclusions: Uremic macrophages exhibit increased HGFIN gene and protein expression and heightened expression of proinflammatory and a suppressed expression of anti-inflammatory cytokines. Further studies are needed to determine the role of heightened monocyte/macrophage HGFIN expression in the pathogenesis of ESRD-induced inflammation and vascular and soft tissue calcification. PMID:19833906

Interactions Between HIV-Infected Monocytes and the Extracellular Matrix: HIV-Infected Monocytes Secrete Neutral Metalloproteases That Degrade Basement Membrane Protein Matrices,

DTIC Science & Technology

1992-08-01

p2 4 antigen (Ag) by flow "cytometry. All cells were recovered from Matrigel (Col- 20• laborative Biomedical Products) after treatment with a bac...of HIV-infected mono- tropic virus originally isolated and passaged in monocytes, at a multiplicity of infection of 0.05 infectious virus/target cell

Endothelial protein C receptor is overexpressed in rheumatoid arthritic (RA) synovium and mediates the anti‐inflammatory effects of activated protein C in RA monocytes

PubMed Central

Xue, Meilang; March, Lyn; Sambrook, Philip N; Fukudome, Kenji; Jackson, Christopher J

2007-01-01

Objectives (1) To investigate whether inflammatory synovial tissues from patients with rheumatoid arthritis (RA) express endothelial protein C receptor (EPCR) and (2) to determine the major cell type(s) that EPCR is associated with and whether EPCR functions to mediate the effects of activated protein C (APC) on these cells. Methods EPCR, CD68 and PC/APC in synovial tissues were detected by immunostaining and in situ PCR. Monocytes were isolated from peripheral blood of patients with RA and treated with APC, lipopolysaccharide (LPS), and/or EPCR blocking antibody RCR252. Cells and supernatants were collected for RT‐PCR, western blotting, enzyme‐linked immuosorbent assay and chemotaxis assay. Results: EPCR was expressed by both OA and RA synovial tissues but was markedly increased in RA synovium. EPCR was colocalised with PC/APC mostly on CD68 positive cells in synovium. In RA monocytes, APC upregulated EPCR expression and reduced monocyte chemoattractant protein‐1‐induced chemotaxis of monocytes by approximately 50%. APC also completely suppressed LPS‐stimulated NF‐κB activation and attenuated TNF‐α protein by more than 40% in RA monocytes. The inhibitory effects of APC were reversed by RCR252, indicating that EPCR is required. Conclusions Our results demonstrate for the first time that EPCR is expressed by synovial tissues, particularly in RA, where it co‐localises with PC/APC on monocytes/macrophages. In addition, APC inhibits the migration and activation of RA monocytes via EPCR. These inhibitory effects on RA monocytes suggest that PC pathway may have a beneficial therapeutic effect in RA. PMID:17491095

Circulating inflammatory monocytes contribute to impaired influenza vaccine responses in HIV-infected participants.

PubMed

George, Varghese K; Pallikkuth, Suresh; Pahwa, Rajendra; de Armas, Lesley R; Rinaldi, Stefano; Pan, Li; Pahwa, Savita

2018-06-19

Antibody responses are often impaired in old age and in HIV-positive (HIV+) infection despite virologic control with antiretroviral therapy but innate immunologic determinants are not well understood. Monocytes and natural killer cells were examined for relationships to age, HIV infection and influenza vaccine responses. Virologically suppressed HIV+ (n = 139) and HIV-negative (HIV-) (n = 137) participants classified by age as young (18-39 years), middle-aged (40-59 years) and old (≥60 years) were evaluated preinfluenza and postinfluenza vaccination. Prevaccination frequencies of inflammatory monocytes were highest in old HIV+ and HIV-, with old HIV+ exhibiting higher frequency of integrin CD11b on inflammatory monocytes that was correlated with age, expression of C-C chemokine receptor-2 (CCR2) and plasma soluble tumor necrosis factor receptor-1 (sTNFR1), with inverse correlation with postvaccination influenza H1N1 antibody titers. Higher frequencies of CD11b inflammatory monocytes (CD11b, >48.4%) compared with low frequencies of CD11b inflammatory monocytes (<15.8%) was associated with higher prevaccination frequencies of total and inflammatory monocytes and higher CCR2 MFI, higher plasma sTNFR1 and CXCL-10 with higher lipopolysaccharide stimulated expression of TNFα and IL-6, concomitant with lower postvaccination influenza antibody titers. In HIV+ CD11b expressers, the depletion of inflammatory monocytes from peripheral blood mononuclear cells resulted in enhanced antigen-specific CD4 T-cell proliferation. Immature CD56 natural killer cells were lower in young HIV+ compared with young HIV- participants. Perturbations of innate immunity and inflammation signified by high CD11b on inflammatory monocytes are exacerbated with aging in HIV+ and negatively impact immune function involved in Ab response to influenza vaccination.

Technical advance: liposomal alendronate depletes monocytes and macrophages in the nonhuman primate model of human disease.

PubMed

Burwitz, Benjamin J; Reed, Jason S; Hammond, Katherine B; Ohme, Merete A; Planer, Shannon L; Legasse, Alfred W; Ericsen, Adam J; Richter, Yoram; Golomb, Gershon; Sacha, Jonah B

2014-09-01

Nonhuman primates are critical animal models for the study of human disorders and disease and offer a platform to assess the role of immune cells in pathogenesis via depletion of specific cellular subsets. However, this model is currently hindered by the lack of reagents that safely and specifically ablate myeloid cells of the monocyte/macrophage Lin. Given the central importance of macrophages in homeostasis and host immunity, development of a macrophage-depletion technique in nonhuman primates would open new avenues of research. Here, using LA at i.v. doses as low as 0.1 mg/kg, we show a >50% transient depletion of circulating monocytes and tissue-resident macrophages in RMs by an 11-color flow cytometric analysis. Diminution of monocytes was followed rapidly by emigration of monocytes from the bone marrow, leading to a rebound of monocytes to baseline levels. Importantly, LA was well-tolerated, as no adverse effects or changes in gross organ function were observed during depletion. These results advance the ex vivo study of myeloid cells by flow cytometry and pave the way for in vivo studies of monocyte/macrophage biology in nonhuman primate models of human disease. © 2014 Society for Leukocyte Biology.

Technical Advance: Liposomal alendronate depletes monocytes and macrophages in the nonhuman primate model of human disease

PubMed Central

Burwitz, Benjamin J.; Reed, Jason S.; Hammond, Katherine B.; Ohme, Merete A.; Planer, Shannon L.; Legasse, Alfred W.; Ericsen, Adam J.; Richter, Yoram; Golomb, Gershon; Sacha, Jonah B.

2014-01-01

Nonhuman primates are critical animal models for the study of human disorders and disease and offer a platform to assess the role of immune cells in pathogenesis via depletion of specific cellular subsets. However, this model is currently hindered by the lack of reagents that safely and specifically ablate myeloid cells of the monocyte/macrophage Lin. Given the central importance of macrophages in homeostasis and host immunity, development of a macrophage-depletion technique in nonhuman primates would open new avenues of research. Here, using LA at i.v. doses as low as 0.1 mg/kg, we show a >50% transient depletion of circulating monocytes and tissue-resident macrophages in RMs by an 11-color flow cytometric analysis. Diminution of monocytes was followed rapidly by emigration of monocytes from the bone marrow, leading to a rebound of monocytes to baseline levels. Importantly, LA was well-tolerated, as no adverse effects or changes in gross organ function were observed during depletion. These results advance the ex vivo study of myeloid cells by flow cytometry and pave the way for in vivo studies of monocyte/macrophage biology in nonhuman primate models of human disease. PMID:24823811

Tracking Monocyte Recruitment and Macrophage Accumulation in Atherosclerotic Plaque Progression Using a Novel hCD68GFP/ApoE−/− Reporter Mouse—Brief Report

PubMed Central

Iqbal, Asif J.; Jones, Daniel; Patel, Jyoti; Coutinho, Patricia; Taylor, Lewis; Greaves, David R.; Channon, Keith M.

2017-01-01

Objective— To create a model of atherosclerosis using green fluorescent protein (GFP)–targeted monocytes/macrophages, allowing analysis of both endogenous GFP+ and adoptively transferred GFP+ myeloid cells in arterial inflammation. Approach and Results— hCD68GFP reporter mice were crossed with ApoE−/− mice. Expression of GFP was localized to macrophages in atherosclerotic plaques and in angiotensin II–induced aortic aneurysms and correlated with galectin 3 and mCD68 expression. Flow cytometry confirmed GFP+ expression in CD11b+/CD64+, CD11c+/MHC-IIHI, and CD11b+/F4/80+ myeloid cells. Adoptive transfer of GFP+ monocytes demonstrated monocyte recruitment to both adventitia and atherosclerotic plaque, throughout the aortic root, within 72 hours. We demonstrated the biological utility of hCD68GFP monocytes by comparing the recruitment of wild-type and CCR2−/− monocytes to sites of inflammation. Conclusions— hCD68GFP/ApoE−/− mice provide a new approach to study macrophage accumulation in atherosclerotic plaque progression and to identify cells recruited from adoptively transferred monocytes. PMID:27908893

The effects of alpha tocopherol supplementation on monocyte function. Decreased lipid oxidation, interleukin 1 beta secretion, and monocyte adhesion to endothelium.

PubMed Central

Devaraj, S; Li, D; Jialal, I

1996-01-01

Low levels of alpha tocopherol are related to a higher incidence of cardiovascular disease and increased intake appears to afford protection against cardiovascular disease. In addition to decreasing LDL oxidation, alpha tocopherol may exert intracellular effects on cells crucial in atherogenesis, such as monocytes. Hence, the aim of this study was to test the effect of alpha tocopherol supplementation on monocyte function relevant to atherogenesis. Monocyte function was assessed in 21 healthy subjects at baseline, after 8 wk of supplementation with d-alpha tocopherol (1,200 IU/d) and after a 6-wk washout phase. The release of reactive oxygen species (superoxide anion, hydrogen peroxide), lipid oxidation, release of the potentially atherogenic cytokine, interleukin 1 beta, and monocyte-endothelial adhesion were studied in the resting state and after activation of the monocytes with lipopolysaccharide at 0, 8, and 14 wk. There was a 2.5-fold increase in plasma lipid-standardized and monocyte alpha tocopherol levels in the supplemented phase. After alpha tocopherol supplementation, there were significant decreases in release of reactive oxygen species, lipid oxidation, IL-1 beta secretion, and monocyte-endothelial cell adhesion, both in resting and activated cells compared with baseline and washout phases. Studies with the protein kinase C inhibitor, Calphostin C, suggest that the inhibition of reactive oxygen species release and lipid oxidation is due to an inhibition of protein kinase C activity by alpha tocopherol. Thus, this study provides novel evidence for an intracellular effect of alpha tocopherol in monocytes that is antiatherogenic. PMID:8698868

Factor H Binds to Extracellular DNA Traps Released from Human Blood Monocytes in Response to Candida albicans

PubMed Central

Halder, Luke D.; Abdelfatah, Mahmoud A.; Jo, Emeraldo A. H.; Jacobsen, Ilse D.; Westermann, Martin; Beyersdorf, Niklas; Lorkowski, Stefan; Zipfel, Peter F.; Skerka, Christine

2017-01-01

Upon systemic infection with human pathogenic yeast Candida albicans (C. albicans), human monocytes and polymorph nuclear neutrophilic granulocytes are the first immune cells to respond and come into contact with C. albicans. Monocytes exert immediate candidacidal activity and inhibit germination, mediate phagocytosis, and kill fungal cells. Here, we show that human monocytes spontaneously respond to C. albicans cells via phagocytosis, decondensation of nuclear DNA, and release of this decondensed DNA in the form of extracellular traps (called monocytic extracellular traps: MoETs). Both subtypes of monocytes (CD14++CD16−/CD14+CD16+) formed MoETs within the first hours upon contact with C. albicans. MoETs were characterized by the presence of citrullinated histone, myeloperoxidase, lactoferrin, and elastase. MoETs were also formed in response to Staphylococcus aureus and Escherichia coli, indicating a general reaction of monocytes to infectious microbes. MoET induction differs from extracellular trap formation in macrophages as MoETs are not triggered by simvastatin, an inhibitor of cholesterol synthesis and inducer of extracellular traps in macrophages. Extracellular traps from both monocytes and neutrophils activate complement and C3b is deposited. However, factor H (FH) binds via C3b to the extracellular DNA, mediates cofactor activity, and inhibits the induction of the inflammatory cytokine interleukin-1 beta in monocytes. Altogether, the results show that human monocytes release extracellular DNA traps in response to C. albicans and that these traps finally bind FH via C3b to presumably support clearance without further inflammation. PMID:28133459

Effects of Low-Level Laser Therapy on M1-Related Cytokine Expression in Monocytes via Histone Modification

PubMed Central

Chen, Chia-Hsin; Wang, Chau-Zen; Wang, Yan-Hsiung; Liao, Wei-Ting; Chen, Yi-Jen; Kuo, Hsuan-Fu; Hung, Chih-Hsing

2014-01-01

Low-level laser therapy (LLLT) has been used in the treatment of radiotherapy-induced oral mucositis and allergic rhinitis. However, the effects of LLLT on human monocyte polarization into M1 macrophages are unknown. To evaluate the effects of LLLT on M1-related cytokine and chemokine production and elucidate the mechanism, the human monocyte cell line THP-1 was treated with different doses of LLLT. The expression of M1-related cytokines and chemokines (CCL2, CXCL10, and TNF-α) was determined by ELISA and real-time PCR. LLLT-associated histone modifications were examined by chromatin immunoprecipitation (ChIP) assays. Mitochondrial involvement in the LLLT-induced M1-related cytokine expression was evaluated by quantitative real-time PCR. Flow cytometry was used to detect the cell surface markers for monocyte polarization. The results showed that LLLT (660 nm) significantly enhanced M1-related cytokine and chemokine expression in mRNA and protein levels. Mitochondrial copy number and mRNA levels of complex I-V protein were increased by LLLT (1 J/cm2). Activation of M1 polarization was concomitant with histone modification at TNF-α gene locus and IP-10 gene promoter area. This study indicates that LLLT (660 nm) enhanced M1-related cytokine and chemokine expression via mitochondrial biogenesis and histone modification, which may be a potent immune-enhancing agent for the treatment of allergic diseases. PMID:24692853

Critical Role for Monocytes/Macrophages in Rapid Progression to AIDS in Pediatric Simian Immunodeficiency Virus-Infected Rhesus Macaques.

PubMed

Sugimoto, Chie; Merino, Kristen M; Hasegawa, Atsuhiko; Wang, Xiaolei; Alvarez, Xavier A; Wakao, Hiroshi; Mori, Kazuyasu; Kim, Woong-Ki; Veazey, Ronald S; Didier, Elizabeth S; Kuroda, Marcelo J

2017-09-01

Infant humans and rhesus macaques infected with the human or simian immunodeficiency virus (HIV or SIV), respectively, express higher viral loads and progress more rapidly to AIDS than infected adults. Activated memory CD4 + T cells in intestinal tissues are major primary target cells for SIV/HIV infection, and massive depletion of these cells is considered a major cause of immunodeficiency. Monocytes and macrophages are important cells of innate immunity and also are targets of HIV/SIV infection. We reported previously that a high peripheral blood monocyte turnover rate was predictive for the onset of disease progression to AIDS in SIV-infected adult macaques. The purpose of this study was to determine if earlier or higher infection of monocytes/macrophages contributes to the more rapid progression to AIDS in infants. We observed that uninfected infant rhesus macaques exhibited higher physiologic baseline monocyte turnover than adults. Early after SIV infection, the monocyte turnover further increased, and it remained high during progression to AIDS. A high percentage of terminal deoxynucleotidyltransferase dUTP nick end label (TUNEL)-positive macrophages in the lymph nodes (LNs) and intestine corresponded with an increasing number of macrophages derived from circulating monocytes (bromodeoxyuridine positive [BrdU + ] CD163 + ), suggesting that the increased blood monocyte turnover was required to rapidly replenish destroyed tissue macrophages. Immunofluorescence analysis further demonstrated that macrophages were a significant portion of the virus-producing cells found in LNs, intestinal tissues, and lungs. The higher baseline monocyte turnover in infant macaques and subsequent macrophage damage by SIV infection may help explain the basis of more rapid disease progression to AIDS in infants. IMPORTANCE HIV infection progresses much more rapidly in pediatric cases than in adults; however, the mechanism for this difference is unclear. Using the rhesus macaque model, this work was performed to address why infants infected with SIV progress more quickly to AIDS than do adults. Earlier we reported that in adult rhesus macaques, increasing monocyte turnover reflected tissue macrophage damage by SIV and was predictive of terminal disease progression to AIDS. Here we report that uninfected infant rhesus macaques exhibited a higher physiological baseline monocyte turnover rate than adults. Furthermore, once infected with SIV, infants displayed further increased monocyte turnover that may have facilitated the accelerated progression to AIDS. These results support a role for monocytes and macrophages in the pathogenesis of SIV/HIV and begin to explain why infants are more prone to rapid disease progression. Copyright © 2017 American Society for Microbiology.

Critical Role for Monocytes/Macrophages in Rapid Progression to AIDS in Pediatric Simian Immunodeficiency Virus-Infected Rhesus Macaques

PubMed Central

Sugimoto, Chie; Merino, Kristen M.; Hasegawa, Atsuhiko; Wang, Xiaolei; Alvarez, Xavier A.; Wakao, Hiroshi; Kim, Woong-Ki; Veazey, Ronald S.; Didier, Elizabeth S.

2017-01-01

ABSTRACT Infant humans and rhesus macaques infected with the human or simian immunodeficiency virus (HIV or SIV), respectively, express higher viral loads and progress more rapidly to AIDS than infected adults. Activated memory CD4+ T cells in intestinal tissues are major primary target cells for SIV/HIV infection, and massive depletion of these cells is considered a major cause of immunodeficiency. Monocytes and macrophages are important cells of innate immunity and also are targets of HIV/SIV infection. We reported previously that a high peripheral blood monocyte turnover rate was predictive for the onset of disease progression to AIDS in SIV-infected adult macaques. The purpose of this study was to determine if earlier or higher infection of monocytes/macrophages contributes to the more rapid progression to AIDS in infants. We observed that uninfected infant rhesus macaques exhibited higher physiologic baseline monocyte turnover than adults. Early after SIV infection, the monocyte turnover further increased, and it remained high during progression to AIDS. A high percentage of terminal deoxynucleotidyltransferase dUTP nick end label (TUNEL)-positive macrophages in the lymph nodes (LNs) and intestine corresponded with an increasing number of macrophages derived from circulating monocytes (bromodeoxyuridine positive [BrdU+] CD163+), suggesting that the increased blood monocyte turnover was required to rapidly replenish destroyed tissue macrophages. Immunofluorescence analysis further demonstrated that macrophages were a significant portion of the virus-producing cells found in LNs, intestinal tissues, and lungs. The higher baseline monocyte turnover in infant macaques and subsequent macrophage damage by SIV infection may help explain the basis of more rapid disease progression to AIDS in infants. IMPORTANCE HIV infection progresses much more rapidly in pediatric cases than in adults; however, the mechanism for this difference is unclear. Using the rhesus macaque model, this work was performed to address why infants infected with SIV progress more quickly to AIDS than do adults. Earlier we reported that in adult rhesus macaques, increasing monocyte turnover reflected tissue macrophage damage by SIV and was predictive of terminal disease progression to AIDS. Here we report that uninfected infant rhesus macaques exhibited a higher physiological baseline monocyte turnover rate than adults. Furthermore, once infected with SIV, infants displayed further increased monocyte turnover that may have facilitated the accelerated progression to AIDS. These results support a role for monocytes and macrophages in the pathogenesis of SIV/HIV and begin to explain why infants are more prone to rapid disease progression. PMID:28566378

A novel anti-inflammatory mechanism of high density lipoprotein through up-regulating annexin A1 in vascular endothelial cells.

PubMed

Pan, Bing; Kong, Jinge; Jin, Jingru; Kong, Jian; He, Yubin; Dong, Shuying; Ji, Liang; Liu, Donghui; He, Dan; Kong, Liming; Jin, David K; Willard, Belinda; Pennathur, Subramaniam; Zheng, Lemin

2016-06-01

High density lipoprotein (HDL) as well as annexin A1 have been reported to be associated with cardiovascular protection. However, the correlation between HDL and annexin A1 was still unknown. In this study, HDL increased endothelial annexin A1 and prevented the decrease of annexin A1 in TNF-α-activated endothelial cells in vitro and in vivo, and above effects were attenuated after knockdown of annexin A1. Annexin A1 modulation affected HDL-mediated inhibition of monocyte adhesion to TNF-α-activated endothelium (45.2±13.7% decrease for annexin A1 RNA interference; 78.7±16.3% decrease for anti-Annexin A1 antibody blocking; 11.2±6.9% increase for Ad-ANXA1 transfection). Additionally, HDL up-regulated annexin A1 through scavenger receptor class B type I, involving ERK, p38MAPK, Akt and PKC signaling pathways, and respective inhibitors of these pathways attenuated HDL-induced annexin A1 expression as well as impaired HDL-mediated inhibition of monocyte-endothelial cell adhesion. Apolipoprotein AI also increased annexin A1 and activated similar signaling pathways. Endothelial annexin A1 from apolipoprotein AI knockout mice was decreased in comparison to that from wild type mice. Finally, HDL-induced annexin A1 inhibited cell surface VCAM-1, ICAM-1 and E-selectin, and secretion of MCP-1, IL-8, VCAM-1 and E-selectin, thereby inhibiting monocyte adhesion. Copyright © 2016 Elsevier B.V. All rights reserved.

Sulforaphane mitigates cadmium-induced toxicity pattern in human peripheral blood lymphocytes and monocytes.

PubMed

Alkharashi, Nouf Abdulkareem Omer; Periasamy, Vaiyapuri Subbarayan; Athinarayanan, Jegan; Alshatwi, Ali A

2017-10-01

Cadmium (Cd) is a highly toxic and widely distributed heavy metal that induces various diseases in humans through environmental exposure. Therefore, alleviation of Cd-induced toxicity in living organisms is necessary. In this study, we investigated the protective role of sulforaphane on Cd-induced toxicity in human peripheral blood lymphocytes and monocytes. Sulforaphane did not show any major reduction in the viability of lymphocytes and monocytes. However, Cd treatment at a concentration of 50μM induced around 69% cell death. Treatment of IC 10 -Cd and 100μM sulforaphane combination for 24 and 48h increased viability by 2 and 9% in cells subjected to Cd toxicity, respectively. In addition, IC 25 of Cd and 100μM sulforaphane combination recovered 17-20% of cell viability. Cd induced apoptotic and necrotic cell death. Sulforaphane treatment reduced Cd-induced cell death in lymphocytes and monocytes. Our results clearly indicate that when the cells were treated with Cd+sulforaphane combination, sulforaphane decreased the Cd-induced cytotoxic effect in lymphocytes and monocytes. In addition, sulforaphane concentration plays a major role in the alleviation of Cd-induced toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Microgravity modifies protein kinase C isoform translocation in the human monocytic cell line U937 and human peripheral blood T-cells

NASA Technical Reports Server (NTRS)

Hatton, Jason P.; Gaubert, Francois; Cazenave, Jean-Pierre; Schmitt, Didier; Hashemi, B. B. (Principal Investigator); Hughes-Fulford, M. (Principal Investigator)

2002-01-01

Individual protein kinase C (PKC) isoforms fulfill distinct roles in the regulation of the commitment to differentiation, cell cycle arrest, and apoptosis in both monocytes and T-cells. The human monocyte like cell line U937 and T-cells were exposed to microgravity, during spaceflight and the translocation (a critical step in PKC signaling) of individual isoforms to cell particulate fraction examined. PKC activating phorbol esters induced a rapid translocation of several PKC isoforms to the particulate fraction of U937 monocytes under terrestrial gravity (1 g) conditions in the laboratory. In microgravity, the translocation of PKC beta II, delta, and epsilon in response to phorbol esters was reduced in microgravity compared to 1 g, but was enhanced in weak hypergravity (1.4 g). All isoforms showed a net increase in particulate PKC following phorbol ester stimulation, except PKC delta which showed a net decrease in microgravity. In T-cells, phorbol ester induced translocation of PKC delta was reduced in microgravity, compared to 1 g, while PKC beta II translocation was not significantly different at the two g-levels. These data show that microgravity differentially alters the translocation of individual PKC isoforms in monocytes and T-cells, thus providing a partial explanation for the modifications previously observed in the activation of these cell types under microgravity.

Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation.

PubMed

Fink, Lisbeth N; Zeuthen, Louise H; Ferlazzo, Guido; Frøkiaer, Hanne

2007-12-01

The intestinal microbiota is essential for homeostasis of the local and systemic immune system, and particularly strains of lactic acid bacteria and Escherichia coli have been shown to have balancing effects on inflammatory conditions such as allergy and inflammatory bowel disease. However, in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN-gamma production was also mediated by all types of APC. The most potent responses were induced by monocyte-derived DC, which thus constitute a sensitive screening model.

Differential expression of lymphocyte function-associated antigen (LFA-1) on peripheral blood leucocytes from individuals with Down's syndrome.

PubMed Central

Barrena, M J; Echaniz, P; Garcia-Serrano, C; Zubillaga, P; Cuadrado, E

1992-01-01

We analysed the expression of lymphocyte function-associated antigen LFA-1 on the cell surface of peripheral blood lymphocytes, monocytes and granulocytes from 20 children with Down's syndrome. No differences in LFA-1 expression was found within monocytes or granulocytes from either normal or Down's syndrome children; however, a clear-cut difference was observed on lymphoid cells. Both normal and Down's syndrome lymphocytes displayed a bimodal pattern of LFA-1 staining by flow cytometry, with a predominance of cells with low expression in normal population, and an increased proportion of lymphocytes with high level of LFA-1 expression in Down's syndrome children. This difference correlates well with the abnormal proportion of T cell subsets and inversion of CD4/CD8 observed in a majority of our cases, and therefore, it could merely reflect the increase of certain T cell subsets normally expressing higher number of LFA-1 molecules. Taken together, our results do not support an abnormally increased expression of leucocytes integrins in trisomy 21 cells, and raise some doubt about the suggested role of the abnormal cellular expression of LFA-1 in the pathogensis of secondary immunodeficiency associated to Down's syndrome. PMID:1348667

Immunosuppressive myeloid cells induced by chemotherapy attenuate antitumor CD4+ T-cell responses through the PD-1-PD-L1 axis.

PubMed

Ding, Zhi-Chun; Lu, Xiaoyun; Yu, Miao; Lemos, Henrique; Huang, Lei; Chandler, Phillip; Liu, Kebin; Walters, Matthew; Krasinski, Antoni; Mack, Matthias; Blazar, Bruce R; Mellor, Andrew L; Munn, David H; Zhou, Gang

2014-07-01

In recent years, immune-based therapies have become an increasingly attractive treatment option for patients with cancer. Cancer immunotherapy is often used in combination with conventional chemotherapy for synergistic effects. The alkylating agent cyclophosphamide (CTX) has been included in various chemoimmunotherapy regimens because of its well-known immunostimulatory effects. Paradoxically, cyclophosphamide can also induce suppressor cells that inhibit immune responses. However, the identity and biologic relevance of these suppressor cells are poorly defined. Here we report that cyclophosphamide treatment drives the expansion of inflammatory monocytic myeloid cells (CD11b(+)Ly6C(hi)CCR2(hi)) that possess immunosuppressive activities. In mice with advanced lymphoma, adoptive transfer (AT) of tumor-specific CD4(+) T cells following cyclophosphamide treatment (CTX+CD4 AT) provoked a robust initial antitumor immune response, but also resulted in enhanced expansion of monocytic myeloid cells. These therapy-induced monocytes inhibited long-term tumor control and allowed subsequent relapse by mediating functional tolerization of antitumor CD4(+) effector cells through the PD-1-PD-L1 axis. PD-1/PD-L1 blockade after CTX+CD4 AT therapy led to persistence of CD4(+) effector cells and durable antitumor effects. Depleting proliferative monocytes by administering low-dose gemcitabine effectively prevented tumor recurrence after CTX+CD4 AT therapy. Similarly, targeting inflammatory monocytes by disrupting the CCR2 signaling pathway markedly potentiated the efficacy of cyclophosphamide-based therapy. Besides cyclophosphamide, we found that melphalan and doxorubicin can also induce monocytic myeloid suppressor cells. These findings reveal a counter-regulation mechanism elicited by certain chemotherapeutic agents and highlight the importance of overcoming this barrier to prevent late tumor relapse after chemoimmunotherapy. ©2014 American Association for Cancer Research.

Speeding up pyrogenicity testing: Identification of suitable cell components and readout parameters for an accelerated monocyte activation test (MAT).

PubMed

Stoppelkamp, Sandra; Würschum, Noriana; Stang, Katharina; Löder, Jasmin; Avci-Adali, Meltem; Toliashvili, Leila; Schlensak, Christian; Wendel, Hans Peter; Fennrich, Stefan

2017-02-01

Pyrogen testing represents a crucial safety measure for parental drugs and medical devices, especially in direct contact with blood or liquor. The European Pharmacopoeia regulates these quality control measures for parenterals. Since 2010, the monocyte activation test (MAT) has been an accepted pyrogen test that can be performed with different human monocytic cell sources: whole blood, isolated monocytic cells or monocytic cell lines with IL1β, IL6, or TNFα as readout cytokines. In the present study, we examined the three different cell sources and cytokine readout parameters with the scope of accelerating the assay time. We could show that despite all cell types being able to detect pyrogens, primary cells were more sensitive than the monocytic cell line. Quantitative real-time PCR revealed IL6 mRNA transcripts having the largest change in Ct-values upon LPS-stimulation compared to IL1β and TNFα, but quantification was unreliable. IL6 protein secretion from whole blood or peripheral blood mononuclear cells (PBMC) was also best suited for an accelerated assay with a larger linear range and higher signal-to-noise ratios upon LPS-stimulation. The unique combination with propan-2-ol or a temperature increase could additionally increase the cytokine production for earlier detection in PBMC. The increased incubation temperature could finally increase not only responses to lipopolysaccharides (LPS) but also other pyrogens by up to 13-fold. Therefore, pyrogen detection can be accelerated considerably by using isolated primary blood cells with an increased incubation temperature and IL6 as readout. These results could expedite assay time and thus help to promote further acceptance of the MAT. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Heat stable antigen (mouse CD24) supports myeloid cell binding to endothelial and platelet P-selectin.

PubMed

Aigner, S; Ruppert, M; Hubbe, M; Sammar, M; Sthoeger, Z; Butcher, E C; Vestweber, D; Altevogt, P

1995-10-01

P-selectin is a Ca(2+)-dependent lectin that participates in leukocyte adhesion to vascular endothelium and platelets. Myeloid cells and a subset of T lymphocytes express carbohydrate ligands at the cell surface. Previously, we suggested that heat stable antigen (HSA/mouse CD24), an extensively glycosylated cell surface molecule on many mouse cells, is a ligand for P-selectin. Here we show that HSA mediates the binding of monocytic cells and neutrophils to P-selectin. The monocytic cell lines ESb-MP and J774, peritoneal exudate cells, and bone marrow neutrophils could bind to lipopolysaccharide-activated bend3 endothelioma cells under rotation-induced shear forces and this binding was inhibited by mAb to P-selectin and HSA. Blocking was weak at room temperature but more efficient at 4 degrees C when integrin-mediated binding was decreased. Also the adhesion of neutrophils to stimulated platelets expressing P-selectin was blocked by HSA- and P-selectin-specific mAb. Latex beads coated with purified HSA from myeloid cells bound to activated endothelioma cells or platelets, and the binding was similarly blocked by mAb to P-selectin and HSA respectively. The HSA-coated beads were stained with P-selectin-IgG, very weakly with L-selectin-IgG but not with E-selectin-IgG. The staining was dependent on divalent cations and treatment with endoglycosidase F or neuraminidase indicated that sialylated N-linked glycans were recognized. The presence of these glycans was confirmed by biosynthetic labeling studies. Our data suggest that HSA, in addition to the recently identified 160 kDa glycoprotein ligand on mouse neutrophils, belongs to a group of monospecific P-selectin ligands on myeloid cells.

Efficient, Long Term Production of Monocyte-Derived Macrophages from Human Pluripotent Stem Cells under Partly-Defined and Fully-Defined Conditions

PubMed Central

van Wilgenburg, Bonnie; Browne, Cathy; Vowles, Jane; Cowley, Sally A.

2013-01-01

Human macrophages are specialised hosts for HIV-1, dengue virus, Leishmania and Mycobacterium tuberculosis. Yet macrophage research is hampered by lack of appropriate cell models for modelling infection by these human pathogens, because available myeloid cell lines are, by definition, not terminally differentiated like tissue macrophages. We describe here a method for deriving monocytes and macrophages from human Pluripotent Stem Cells which improves on previously published protocols in that it uses entirely defined, feeder- and serum-free culture conditions and produces very consistent, pure, high yields across both human Embryonic Stem Cell (hESC) and multiple human induced Pluripotent Stem Cell (hiPSC) lines over time periods of up to one year. Cumulatively, up to ∼3×107 monocytes can be harvested per 6-well plate. The monocytes produced are most closely similar to the major blood monocyte (CD14+, CD16low, CD163+). Differentiation with M-CSF produces macrophages that are highly phagocytic, HIV-1-infectable, and upon activation produce a pro-inflammatory cytokine profile similar to blood monocyte-derived macrophages. Macrophages are notoriously hard to genetically manipulate, as they recognise foreign nucleic acids; the lentivector system described here overcomes this, as pluripotent stem cells can be relatively simply genetically manipulated for efficient transgene expression in the differentiated cells, surmounting issues of transgene silencing. Overall, the method we describe here is an efficient, effective, scalable system for the reproducible production and genetic modification of human macrophages, facilitating the interrogation of human macrophage biology. PMID:23951090

FC-99 ameliorates sepsis-induced liver dysfunction by modulating monocyte/macrophage differentiation via Let-7a related monocytes apoptosis

PubMed Central

Zhao, Yarong; Zhu, Haiyan; Wang, Haining; Ding, Liang; Xu, Lizhi; Chen, Dai; Shen, Sunan; Hou, Yayi; Dou, Huan

2018-01-01

Background The liver is a vital target for sepsis-related injury, leading to inflammatory pathogenesis, multiple organ dysfunction and high mortality rates. Monocyte-derived macrophage transformations are key events in hepatic inflammation. N1-[(4-methoxy)methyl]-4-methyl-1,2-benzenediamine (FC-99) previously displayed therapeutic potential on experimental sepsis. However, the underlying mechanism of this protective effect is still not clear. Results FC-99 treatment attenuated the liver dysfunction in septic mice that was accompanied with reduced numbers of pro-inflammatory Ly6Chi monocytes in the peripheral blood and CD11b+F4/80lo monocyte-derived macrophages in the liver. These effects were attributed to the FC-99-induced apoptosis of CD11b+ cells. In PMA-differentiated THP-1 cells, FC-99 repressed the expression of CD11b, CD14 and caspase3 and resulted in a high proportion of Annexin V+ cells. Moreover, let-7a-5p expression was abrogated upon CLP stimulation in vivo, whereas it was restored by FC-99 treatment. TargetScan analysis and luciferase assays indicated that the anti-apoptotic protein BCL-XL was targeted by let-7a-5p. BCL-XL was inhibited by FC-99 in order to induce monocyte apoptosis, leading to the impaired monocyte-to-macrophage differentiation. Materials and Methods Murine acute liver failure was generated by caecal ligation puncture surgery after FC-99 administration; Blood samples and liver tissues were collected to determine the monocyte/macrophage subsets and the induction of apoptosis. Human acute monocytic leukemia cell line (THP-1) cells were pretreated with FC-99 followed by phorbol-12-myristate-13-acetate (PMA) stimulation, in order to induce monocyte-to-macrophage differentiation. The target of FC-99 and the mechanistic analyses were conducted by microarrays, qRT-PCR validation, TargetScan algorithms and a luciferase report assay. Conclusions FC-99 exhibits potential therapeutic effects on CLP-induced liver dysfunction by restoring let-7a-5p levels. PMID:29599918

HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcγRs1

PubMed Central

Valenzuela, Nicole M; Mulder, Arend; Reed, Elaine F

2013-01-01

Antibody-mediated rejection of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor specific antibody binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the antibody. We investigated the mechanisms underlying monocyte recruitment by HLA class I antibody-activated endothelium. We used a panel of murine monoclonal antibodies of different subclasses to crosslink HLA I on human aortic, venous and microvascular endothelial cells, and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. Mouse IgG2a but not mIgG1 could bind human FcγRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcγRI, and, to a lesser extent, FcγRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during antibody mediated rejection. We confirmed these observations using human HLA allele specific monoclonal antibodies and IgG purified from transplant patient sera. HLA I antibodies universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during antibody-mediated rejection. Importantly, the subclass of donor specific antibody may influence its pathogenesis. These results imply that hIgG1 and hIgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcγR interactions. PMID:23690477

HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcγRs.

PubMed

Valenzuela, Nicole M; Mulder, Arend; Reed, Elaine F

2013-06-15

Ab-mediated rejection (AMR) of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor-specific Ab binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the Ab. We investigated the mechanisms underlying monocyte recruitment by HLA class I (HLA I) Ab-activated endothelium. We used a panel of murine mAbs of different subclasses to crosslink HLA I on human aortic, venous, and microvascular endothelial cells and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine (m)IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. mIgG2a but not mIgG1 could bind human FcγRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcγRI, and, to a lesser extent, FcγRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during AMR. We confirmed these observations using human HLA allele-specific mAbs and IgG purified from transplant patient sera. HLA I Abs universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during AMR. Importantly, the subclass of donor-specific Ab may influence its pathogenesis. These results imply that human IgG1 and human IgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcγR interactions.

Depletion of CD11c⁺ cells in the CD11c.DTR model drives expansion of unique CD64⁺ Ly6C⁺ monocytes that are poised to release TNF-α.

PubMed

Sivakumaran, Shivajanani; Henderson, Stephen; Ward, Sophie; Sousa, Pedro Santos E; Manzo, Teresa; Zhang, Lei; Conlan, Thomas; Means, Terry K; D'Aveni, Maud; Hermine, Olivier; Rubio, Marie-Thérèse; Chakraverty, Ronjon; Bennett, Clare L

2016-01-01

Dendritic cells (DCs) play a vital role in innate and adaptive immunities. Inducible depletion of CD11c(+) DCs engineered to express a high-affinity diphtheria toxin receptor has been a powerful tool to dissect DC function in vivo. However, despite reports showing that loss of DCs induces transient monocytosis, the monocyte population that emerges and the potential impact of monocytes on studies of DC function have not been investigated. We found that depletion of CD11c(+) cells from CD11c.DTR mice induced the expansion of a variant CD64(+) Ly6C(+) monocyte population in the spleen and blood that was distinct from conventional monocytes. Expansion of CD64(+) Ly6C(+) monocytes was independent of mobilization from the BM via CCR2 but required the cytokine, G-CSF. Indeed, this population was also expanded upon exposure to exogenous G-CSF in the absence of DC depletion. CD64(+) Ly6C(+) monocytes were characterized by upregulation of innate signaling apparatus despite the absence of inflammation, and an increased capacity to produce TNF-α following LPS stimulation. Thus, depletion of CD11c(+) cells induces expansion of a unique CD64(+) Ly6C(+) monocyte population poised to synthesize TNF-α. This finding will require consideration in experiments using depletion strategies to test the role of CD11c(+) DCs in immunity. © 2015 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Involvement of NK cells against tumors and parasites.

PubMed

Papazahariadou, M; Athanasiadis, G I; Papadopoulos, E; Symeonidou, I; Hatzistilianou, M; Castellani, M L; Bhattacharya, K; Shanmugham, L N; Conti, P; Frydas, S

2007-01-01

Host resistance against pathogens depends on a complex interplay of innate and adaptive immune mechanisms. Acting as an early line of defence, the immune system includes activation of neutrophils, tissue macrophages, monocytes, dendritic cells, eosinophils and natural killer (NK) cells. NK cells are lymphoid cells that can be activated without previous stimulation and are therefore like macrophages in the first line of defence against tumor cells and a diverse range of pathogens. NK cells mediate significant activity and produce high levels of proinflammatory cytokines in response to infection. Their cytotoxicity production is induced principally by monocyte-, macrophage- and dendritic cell-derived cytokines, but their activation is also believed to be cytokine-mediated. Recognition of infection by NK cells is accomplished by numerous activating and inhibitory receptors on the NK cells' surface that selectively trigger the cytolytic activity in a major histocompability complex-independent manner. NK cells have trypanocidal activity of fibroblast cells and mediate direct destruction of extracellular epimastigote and trypomastigote forms of T. cruzi and T. lewisi in vitro; moreover, they kill plasmodia-infected erythrocytes directly through cell-cell interaction. This review provides a more detailed analysis of how NK cells recognize and respond to parasites and how they mediate cytotoxicity against tumor cells. Also the unique role of NK cells in innate immunity to infection and the relationship between parasites and carcinogenesis are discussed.

Capsaicin-mediated apoptosis of human bladder cancer cells activates dendritic cells via CD91.

PubMed

Gilardini Montani, Maria Saveria; D'Eliseo, Donatella; Cirone, Mara; Di Renzo, Livia; Faggioni, Alberto; Santoni, Angela; Velotti, Francesca

2015-04-01

Immunostimulation by anticancer cytotoxic drugs is needed for long-term therapeutic success. Activation of dendritic cells (DCs) is crucial to obtain effective and long-lasting anticancer T-cell mediated immunity. The aim of this study was to explore the effect of capsaicin-mediated cell death of bladder cancer cells on the activation of human monocyte-derived CD1a+ immature DCs. Immature DCs (generated from human peripheral blood-derived CD14+ monocytes cultured with granulocyte-macrophage colony stimulating factor and interleukin-4) were cocultured with capsaicin (CPS)-induced apoptotic bladder cancer cells. DC activation was investigated using immunofluorescence and flow cytometric analysis for key surface molecules. In some experiments, CD91 was silenced in immature DCs. We found that capsaicin-mediated cancer cell apoptosis upregulates CD86 and CD83 expression on DCs, indicating the induction of DC activation. Moreover, silencing of CD91 (a common receptor for damage-associated molecular patterns, such as calreticulin and heat-shock protein-90/70) in immature DCs led to the inhibition of DC activation. Our data show that CPS-mediated cancer cell apoptosis activates DCs via CD91, suggesting CPS as an attractive candidate for cancer therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Plasma from preeclamptic women activates endothelial cells via monocyte activation in vitro.

PubMed

Faas, Marijke M; van Pampus, Maria G; Anninga, Zwanine A; Salomons, Jet; Westra, Inge M; Donker, Rogier B; Aarnoudse, Jan G; de Vos, Paul

2010-12-01

In this study we tested whether plasma from preeclamptic women contains factors that can activate endothelial cells in the presence of monocytes in vitro. Plasma from preeclamptic women (n=6), healthy pregnant women (n=6) and nonpregnant women (n=6) was incubated with mono-cultures and co-cultures of human umbilical vein endothelial cells (HUVEC) and monomac-6 monocytes. Reactive oxygen species (ROS) production and ICAM-1 expression were measured using flow cytometry. Whether scavenging of ROS by superoxide dismutase and catalase inhibited HUVEC ICAM-1 expression was also investigated. We found that in HUVEC co-cultured with monomac-6 cells but not in HUVEC cultured alone, ICAM-1 was upregulated after incubation with plasma from preeclamptic women but not plasma from non-pregnant women. Also in co-cultures, monomac-6 ICAM-1 was upregulated by plasma from preeclamptic women, while in both mono- and co-cultures monomac-6 ROS production was upregulated by plasma from pregnant and preeclamptic women, compared with plasma from non-pregnant women. Scavenging of ROS by superoxide dismutase and catalase resulted in a further upregulation of HUVEC ICAM-1 after incubation with plasma from preeclamptic women, compared with incubation without superoxide dismutase and catalase. These results show that endothelial cells in vitro are activated by plasma of preeclamptic women only if they are co-cultured with monocytes. This upregulation appeared not to be due to extracellular ROS production by monocytes or HUVEC, pointing to involvement of other mechanisms. Our data suggest that plasma of preeclamptic women activates monocytes, and that these monocytes subsequently activate endothelial cells. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Expression profiling feline peripheral blood monocytes identifies a transcriptional signature associated with type two diabetes mellitus.

PubMed

O'Leary, Caroline A; Sedhom, Mamdouh; Reeve-Johnson, Mia; Mallyon, John; Irvine, Katharine M

2017-04-01

Diabetes mellitus is a common disease of cats and is similar to type 2 diabetes (T2D) in humans, especially with respect to the role of obesity-induced insulin resistance, glucose toxicity, decreased number of pancreatic β-cells and pancreatic amyloid deposition. Cats have thus been proposed as a valuable translational model of T2D. In humans, inflammation associated with adipose tissue is believed to be central to T2D development, and peripheral blood monocytes (PBM) are important in the inflammatory cascade which leads to insulin resistance and β-cell failure. PBM may thus provide a useful window to study the pathogenesis of diabetes mellitus in cats, however feline monocytes are poorly characterised. In this study, we used the Affymetrix Feline 1.0ST array to profile peripheral blood monocytes from 3 domestic cats with T2D and 3 cats with normal glucose tolerance. Feline monocytes were enriched for genes expressed in human monocytes, and, despite heterogeneous gene expression, we identified a T2D-associated expression signature associated with cell cycle perturbations, DNA repair and the unfolded protein response, oxidative phosphorylation and inflammatory responses. Our data provide novel insights into the feline monocyte transcriptome, and support the hypothesis that inflammatory monocytes contribute to T2D pathogenesis in cats as well as in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Neuropeptide Y Negatively Influences Monocyte Recruitment to the Central Nervous System during Retrovirus Infection.

PubMed

Woods, Tyson A; Du, Min; Carmody, Aaron; Peterson, Karin E

2015-12-30

Monocyte infiltration into the CNS is a hallmark of several viral infections of the central nervous system (CNS), including retrovirus infection. Understanding the factors that mediate monocyte migration in the CNS is essential for the development of therapeutics that can alter the disease process. In the current study, we found that neuropeptide Y (NPY) suppressed monocyte recruitment to the CNS in a mouse model of polytropic retrovirus infection. NPY(-/-) mice had increased incidence and kinetics of retrovirus-induced neurological disease, which correlated with a significant increase in monocytes in the CNS compared to wild-type mice. Both Ly6C(hi) inflammatory and Ly6C(lo) alternatively activated monocytes were increased in the CNS of NPY(-/-) mice following virus infection, suggesting that NPY suppresses the infiltration of both cell types. Ex vivo analysis of myeloid cells from brain tissue demonstrated that infiltrating monocytes expressed high levels of the NPY receptor Y2R. Correlating with the expression of Y2R on monocytes, treatment of NPY(-/-) mice with a truncated, Y2R-specific NPY peptide suppressed the incidence of retrovirus-induced neurological disease. These data demonstrate a clear role for NPY as a negative regulator of monocyte recruitment into the CNS and provide a new mechanism for suppression of retrovirus-induced neurological disease. Monocyte recruitment to the brain is associated with multiple neurological diseases. However, the factors that influence the recruitment of these cells to the brain are still not well understood. In the current study, we found that neuropeptide Y, a protein produced by neurons, affected monocyte recruitment to the brain during retrovirus infection. We show that mice deficient in NPY have increased influx of monocytes into the brain and that this increase in monocytes correlates with neurological-disease development. These studies provide a mechanism by which the nervous system, through the production of NPY, can suppress monocyte trafficking to the brain and reduce retrovirus-induced neurological disease. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Enhanced expression of extracellular calcium sensing receptor in monocyte-differentiated versus undifferentiated HL-60 cells: potential role in regulation of a nonselective cation channel

NASA Technical Reports Server (NTRS)

Yamaguchi, T.; Ye, C.; Chattopadhyay, N.; Sanders, J. L.; Vassilev, P. M.; Brown, E. M.; O'Malley, B. W. (Principal Investigator)

2000-01-01

Human promyelocytic leukemia cells (HL-60) have been used widely as a model for studying the differentiation of hematopoietic progenitor cells in vitro. After treatment with phorbol-12-myristate-13-acetate (PMA) or 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], HL-60 cells differentiate into cells with the phenotype of monocytes/macrophages. We previously showed that peripheral blood monocytes and the murine J774 monocytic cell line express the CaR, and myeloid progenitors in the bone marrow and myeloid cells in peripheral blood other than monocytes express lower levels of the CaR. Therefore, we investigated whether undifferentiated HL-60 cells express a functional G protein-coupled, extracellular calcium (Ca(2+)(o))-sensing receptor (CaR) and if the expression of the CaR increases as these cells differentiate along the monocytic lineage. The use of reverse transcription-polymerase chain reaction (RT-PCR) with CaR-specific primers, followed by sequencing of the amplified products, identified an authentic CaR transcript in undifferentiated HL-60 cells. Both immunocytochemistry and Western blot analysis using a CaR-specific antiserum detected low levels of CaR protein expression in undifferentiated HL-60 cells. The levels of CaR protein increased considerably following treatment of the cells with PMA (50 nM) or 1,25(OH)(2)D(3) (100 nM) for 5 days. Northern analysis using a CaR-specific riboprobe identified CaR transcripts in undifferentiated HL-60 cells, but CaR mRNA levels did not change appreciably after treatment with either agent, suggesting that upregulation of CaR protein occurs at a translational level. PMA-treated HL-60 cells expressed a nonselective cation channel (NCC), and the calcimimetic CaR activator, NPS R-467, but not its less active stereoisomer, NPS S-467, as well as the polycationic CaR agonist, neomycin, activated this NCC, demonstrating that the CaR expressed in these cells is functionally active. Therefore, HL-60 cells exhibit an increase in CaR protein expression, occurring at a translational level during their differentiation into cells with a monocyte/macrophage phenotype in response to treatment with PMA or 1, 25(OH)(2)D(3), which is functionally linked to activation of a nonselective cation channel.

Analysis of peroxidase-negative acute unclassifiable leukemias by monoclonal antibodies. 1. Acute myelogenous leukemia and acute myelomonocytic leukemia.

PubMed

Imamura, N; Tanaka, R; Kajihara, H; Kuramoto, A

1988-11-01

In this study, pretreatment peripheral and/or bone marrow blasts from 12 patients with acute unclassifiable leukemia (AUL) expressing the myeloid-related cell-surface antigen (CD 11) were isolated for further analysis. Despite a lack of myeloperoxidase (MPO) activity, 1 patient's blasts contained cytoplasmic Auer rods. The circulating blasts from another patient expressed MPO while maintaining the same surface phenotype during 20 months of clinical follow-up. In addition, the blasts from 3 cases demonstrated both myelomonocytic and monocyte-specific surface antigens, whereas the remaining 9 cases completely lacked any monocyte-specific antigen detectable by monoclonal antibodies, Mo2, My4 and Leu M3 (CD 14). The first case eventually was diagnosed as acute myelomonocytic leukemia and the second as acute myelogenous leukemia by means of immunophenotypic analysis using flow cytometry (FACS IV). In addition, the presence of MPO protein was identified in the cytoplasm of blast cells from 5 patients with AUL by means of a cytoplasmic immunofluorescence test using a monoclonal antibody (MA1). Our study indicates that non-T, non-B AUL expressing OKM1 (CD 11) antigens include acute leukemias which are unequivocally identifiable as being of either myeloid or myelomonocytic origin. However, further investigations, including immunophenotypic and cytoplasmic analysis, ultrastructural cytochemistry and gene analysis with molecular probes (tests applicable to normal myeloid cells), are necessary in order to determine the actual origin of blasts and to recognize the differentiation stages of the various types of leukemic cells from patients with undifferentiated forms of leukemia.

Histamine release and fibrinogen adsorption mediate acute inflammatory responses to biomaterial implants in humans

PubMed Central

Zdolsek, Johann; Eaton, John W; Tang, Liping

2007-01-01

Background Medical implants often fail as a result of so-called foreign body reactions during which inflammatory cells are recruited to implant surfaces. Despite the clinical importance of this phenomenon, the mechanisms involved in these reactions to biomedical implants in humans are not well understood. The results from animal studies suggest that both fibrinogen adsorption to the implant surface and histamine release by local mast cells are involved in biomaterial-mediated acute inflammatory responses. The purpose of this study was to test this hypothesis in humans. Methods Thirteen male medical student volunteers (Caucasian, 21–30 years of age) were employed for this study. To assess the importance of fibrinogen adsorption, six volunteers were implanted with polyethylene teraphthalate disks pre-coated with their own (fibrinogen-containing) plasma or (fibrinogen-free) serum. To evaluate the importance of histamine, seven volunteers were implanted with uncoated disks with or without prior oral administration of histamine receptor antagonists. The acute inflammatory response was estimated 24 hours later by measuring the activities of implant-associated phagocyte-specific enzymes. Results Plasma coated implants accumulated significantly more phagocytes than did serum coated implants and the recruited cells were predominantly macrophage/monocytes. Administration of both H1 and H2 histamine receptor antagonists greatly reduced the recruitment of macrophages/monocytes and neutrophils on implant surfaces. Conclusion In humans – as in rodents – biomaterial-mediated inflammatory responses involve at least two crucial events: histamine-mediated phagocyte recruitment and phagocyte accumulation on implant surfaces engendered by spontaneously adsorbed host fibrinogen. Based on these results, we conclude that reducing fibrinogen:surface interactions should enhance biocompatibility and that administration of histamine receptor antagonists prior to, and shortly after, medical device implantation should improve the functionality and longevity of medical implants. PMID:17603911

EFFECT OF LIPOSOMAL CLODRONATE-DEPENDENT DEPLETION OF PROFESSIONAL ANTIGEN PRESENTING CELLS ON NUMBERS AND PHENOTYPE OF CANINE CD4+CD25+FOXP3+ REGULATORY T CELLS

PubMed Central

Weaver, Kriston F.; Stokes, John V.; Gunnoe, Sagen A.; Follows, Joyce S.; Shafer, Lydia; Ammari, Mais G.; Archer, Todd M.; Thomason, John M.; Mackin, Andrew J.; Pinchuk, Lesya M.

2015-01-01

Regulatory T cells (Tregs) are known to control autoreactivity during and subsequent to the development of the peripheral immune system. Professional antigen presenting cells (APCs), dendritic cells (DCs) and monocytes, have an important role in inducing Tregs. For the first time, this study evaluated proportions and phenotypes of Tregs in canine peripheral blood depleted of professional APCs, utilizing liposomal clodronate (LC) and multicolor flow cytometry analysis. Our results demonstrate that LC exposure promoted short term decreases followed by significant increases in the proportions or absolute numbers of CD4+CD25+FOXP3+ Tregs in dogs. In general, the LC-dependent Treg fluctuations were similar to the changes in the levels of CD14+ monocytes in Walker hounds. However, the proportions of monocytes showed more dramatic changes compared to the proportions of Tregs that were visually unchanged after LC treatment over the study period. At the same time, absolute Treg numbers showed, similarly to the levels of CD14+ monocytes, significant compensatory gains as well as the recovery during the normalization period. We confirm the previous data that CD4+ T cells with the highest CD25 expression were highly enriched for FOXP3. Furthermore, for the first time, we report that CD4+CD25lowFOXP3+ is the major regulatory T cell subset affected by LC exposure. The increases within the lowest CD25 expressers of CD4+FOXP3+ cells together with compensatory gains in the proportion of CD14+ monocytes during compensatory and normalization periods suggest the possible direct or indirect roles of monocytes in active recruitment and generation of Tregs from naïve CD4+ T cells. PMID:25950023

Enhanced phosphorylation of STAT1 is dependent on PKR signaling in HLA-B27 expressing U937 monocytic cells

PubMed Central

Ruuska, Marja; Sahlberg, Anna S.; Colbert, Robert A.; Granfors, Kaisa; Penttinen, Markus A.

2011-01-01

Objective To study the phosphorylation of STAT1 in HLA-B27-transfected human monocytic cells and the role of signaling molecules PKR and p38 in STAT1 phosphorylation. Methods U937 human monocytic cell transfectants stably expressing wild type HLA-B27 or mutated HLA-B27 heavy chains (HC) with amino acid substitutions in the B pocket were prepared. Mock transfected cells were prepared using the antibiotic resistance vectors (pSV2neo or RSV5neo) alone. PMA differentiated cells were stimulated with LPS or infected with S. enteritidis. Western blotting and flow cytometry were used to detect the phosphorylation and expression levels of STAT1 protein. Specific inhibitors were added in cell culture to study the role of PKR and p38 on STAT1 phosphorylation. Results STAT1 is constitutively highly phosphorylated on tyrosine 701 residue in HLA-B27 positive monocytic cells when compared to control cells, even prior to stimulation with LPS or bacteria. This phenotype is associated with the expression of HLA-B27 HCs that misfold. In addition, phosphorylation of STAT1 is dependent on PKR. Conclusion Our results show that STAT1 tyrosine 701 is constitutively highly phosphorylated in HLA-B27 expressing monocyte-macrophage cell line. Since phosphorylation of tyrosine 701 on STAT1 is sufficient to induce interferon-dependent genes, constitutive activity of this phosphorylation site may lead to overexpression of interferon-dependent genes, as well as other STAT1-dependent genes, in HLA-B27 monocyte-macrophages. Our results offer a mechanism by which B27 expression alone, without any external trigger, is potentially capable of inducing activation of STAT1, a critical regulator of the inflammatory response. PMID:21968657

MCP-1-Induced Protein Promotes Endothelial-Like and Angiogenic Properties in Human Bone Marrow Monocytic Cells

PubMed Central

Wang, Kangkai; Zhelyabovska, Olga; Saad, Yasser; Kolattukudy, Pappachan E.

2013-01-01

Monocytic cells enhance neovascularization by releasing proangiogenic mediators and/or by transdifferentiating into endothelial-like cells. However, the mechanisms that govern this transdifferentiation process are largely unknown. Recently, monocyte chemotactic protein-1 (MCP-1)-induced protein (MCPIP) has been identified as a novel CCCH-type zinc-finger protein expressed primarily in monocytic cells. Here, we analyzed whether MCPIP might exert angiogenic effects by promoting differentiation of monocytic cells into endothelial cell (EC)-like phenotype. The expression of MCPIP increased during MCP-1-induced transdifferentiation in human bone marrow mononuclear cells (BMNCs). Knockdown of MCPIP with small interfering RNA (siRNA) abolished MCP-1-induced expression of EC markers Flk-1 and Tie-2 in human BMNCs. BMNCs transfected with MCPIP expression vector displayed EC-like morphology accompanied by downregulation of monocytic markers CD14 and CD11b, upregulation of EC markers Flk-1 and Tie-2, induction of cadherin (cdh)-12 and -19, activation of endoplasmic reticulum (ER) stress, and autophagy. Knockdown of cdh-12 or cdh-19 markedly inhibited MCPIP-induced enhancement of cell attachment and EC-marker expression. Inhibition of ER stress by tauroursodeoxycholate abolished MCPIP-induced expression of EC markers. Inhibition of autophagy by knockdown of Beclin-1 with siRNA or by an autophagy inhibitor 3′-methyladenine inhibited MCPIP-induced expression of EC markers. Expression of MCPIP in BMNCs enhanced uptake of acetylated low-density lipoprotein (acLDL), formation of EC-colony, incorporation of cells into capillary-like structure on Matrigel, and exhibited increased neovascularization in the ischemic hindlimb in mice. These results demonstrate that MCPIP may be an important regulator of inflammatory angiogenesis and provide novel mechanistic insights into the link between MCP-1 and cardiovascular diseases. PMID:24008336

Mesenteric Th1 polarization and monocyte TNF-alpha production: first steps to systemic inflammation in rats with cirrhosis.

PubMed

Muñoz, Leticia; Albillos, Agustín; Nieto, Mónica; Reyes, Eduardo; Lledó, Lourdes; Monserrat, Jorge; Sanz, Eva; de la Hera, Antonio; Alvarez-Mon, Melchor

2005-08-01

A systemic inflammatory state with increased circulating tumor necrosis factor alpha (TNF-alpha) has been related to the bacterial infection susceptibility and hemodynamic derangement of patients with cirrhosis. We compared the activation status of immune cell subpopulations defined by 4-color cytometry in mesenteric and peripheral lymph nodes and blood of rats with CCl(4)-cirrhosis to define the immune response initiation site, the T-cell and monocyte contribution to pro-inflammatory cytokine production, as well as the pathogenic role of enteric bacteria in the cirrhosis immune response. Th1 cells and monocytes were expanded in the mesenteric nodes (P < .001) and blood (P < .001) of rats with cirrhosis, and activated to produce interferon gamma (P < .0001) and TNF-alpha (P < .0001), respectively. The greater numbers of recently activated CD134(+) Th cells in mesenteric nodes compared with blood, the correlation between their numbers in mesenteric nodes and blood (r = 0.66, P < .001), and the expansion of activated CD45RC(-) Th cells, which are unable to re-enter lymph nodes, in mesenteric nodes but not in blood or axillary nodes points to mesenteric nodes as the origin site of activated Th cells. Abrogation of bacterial translocation by bowel decontamination reduced the number of activated Th cells and monocytes, and normalized interferon gamma production by Th cells and TNF-alpha production by monocytes in mesenteric nodes and blood, respectively. In conclusion, in cirrhosis, enteric bacteria start off an orchestrated immune response cascade in mesenteric nodes involving Th1 polarization and monocyte activation to TNF-alpha production. Later, the recirculation of these activated effector immune cells into blood promotes systemic inflammation.

Regulation of the steady state level of Fc gamma RI mRNA by IFN-gamma and dexamethasone in human monocytes, neutrophils, and U-937 cells.

PubMed

Pan, L Y; Mendel, D B; Zurlo, J; Guyre, P M

1990-07-01

The high affinity IgG FcR Fc gamma RI, CD64, plays important roles in the immune response. Fc gamma RI is predominantly expressed on monocytes and macrophages, and barely detectable on neutrophils. rIFN-gamma markedly increases the expression of Fc gamma RI on neutrophils, monocytes, macrophages and myeloid cell lines such as U-937, HL-60, and THP-1. Glucocorticoids inhibit the augmentation of Fc gamma RI expression by rIFN-gamma on neutrophils and myeloid cell lines, but enhance the augmentation of Fc gamma RI expression by rIFN-gamma on monocytes. In this study, we examined the effect of rIFN-gamma and dexamethasone (Dex) on the steady state level of Fc gamma RI mRNA in U-937 cells, neutrophils, and monocytes by hybridizing total RNA with the Fc gamma RI cDNA probe, p135. We found that the amount of Fc gamma RI mRNA increased within 1 h of treatment with rIFN-gamma in all three cell types. This initial induction of Fc gamma RI mRNA by rIFN-gamma was completely blocked by an inhibitor of RNA synthesis, actinomycin D, suggesting that the rIFN-gamma-mediated induction of Fc gamma RI mRNA is dependent on gene transcription. Dex, used in combination with rIFN-gamma, partially blocked the induction of Fc gamma RI mRNA by rIFN-gamma in U-937 cells and neutrophils, but caused a synergistic increase in Fc gamma RI mRNA levels in monocytes. The inhibitory effect of Dex on the steady state level of Fc gamma RI mRNA in U-937 cells was blocked by an inhibitor of protein synthesis, cycloheximide, suggesting that Dex-induced proteins were involved in the regulation of Fc gamma RI expression. This study indicates that the regulation of Fc gamma RI expression on U-937 cells, neutrophils, and monocytes by rIFN-gamma and Dex occurs, at least in part, at the mRNA level. rIFN-gamma increases the steady state level of Fc gamma RI mRNA through a common pathway among U-937 cells, neutrophils, and monocytes, whereas the effect of Dex on rIFN-gamma-induced Fc gamma RI mRNA is cell-type specific.

Specific depletion of Ly6C(hi) inflammatory monocytes prevents immunopathology in experimental cerebral malaria.

PubMed

Schumak, Beatrix; Klocke, Katrin; Kuepper, Janina M; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6C(hi) inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6C(hi) inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6C(hi) inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.

Specific Depletion of Ly6Chi Inflammatory Monocytes Prevents Immunopathology in Experimental Cerebral Malaria

PubMed Central

Kuepper, Janina M.; Biswas, Aindrila; Djie-Maletz, Andrea; Limmer, Andreas; van Rooijen, Nico; Mack, Matthias; Hoerauf, Achim; Dunay, Ildiko Rita

2015-01-01

Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6Chi inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6Chi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6Chi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes. PMID:25884830

CD4-CCR5 interaction in intracellular compartments contributes to receptor expression at the cell surface

PubMed Central

Achour, Lamia; Scott, Mark G.H.; Shirvani, Hamasseh; Thuret, Alain; Bismuth, Georges; Labbé-Jullié, Catherine; Marullo, Stefano

2009-01-01

The association of CD4, a glycoprotein involved in T cell development and antigen recognition, and CCR5, a chemotactic G protein-coupled receptor, which regulates trafficking and effector functions of immune cells, forms the main receptor for the human immunodeficiency virus HIV. We observed that the vast majority of CCR5 is maintained within the intracellular compartments of primary T lymphocytes and in a monocytic cell line, contrasting with its relative low density at the cell surface. The CCR5-CD4 association, which occurs in the endoplasmic reticulum, enhanced CCR5 export to the plasma membrane in a concentration–dependent manner, whereas inhibition of endogenous CD4 with small interfering RNAs decreased cell surface expression of endogenous CCR5. This effect was specific for CCR5, as CD4 did not affect cell distribution of CXCR4, the other HIV co-receptor. These results reveal a previously unappreciated role of CD4, which contributes to regulate CCR5 export to the plasma membrane. PMID:19064722

iRhom2 regulates CSF1R cell surface expression and non-steady state myelopoiesis in mice.

PubMed

Qing, Xiaoping; Rogers, Lindsay; Mortha, Arthur; Lavin, Yonit; Redecha, Patricia; Issuree, Priya D; Maretzky, Thorsten; Merad, Miriam; McIlwain, David; Mak, Tak W; Overall, Christopher M; Blobel, Carl P; Salmon, Jane E

2016-12-01

CSF1R (colony stimulating factor 1 receptor) is the main receptor for CSF1 and has crucial roles in regulating myelopoeisis. CSF1R can be proteolytically released from the cell surface by ADAM17 (A disintegrin and metalloprotease 17). Here, we identified CSF1R as a major substrate of ADAM17 in an unbiased degradomics screen. We explored the impact of CSF1R shedding by ADAM17 and its upstream regulator, inactive rhomboid protein 2 (iRhom2, gene name Rhbdf2), on homeostatic development of mouse myeloid cells. In iRhom2-/- mice, we found constitutive accumulation of membrane-bound CSF1R on myeloid cells at steady state, although cell numbers of these populations were not altered. However, in the context of mixed bone marrow (BM) chimera, under competitive pressure, iRhom2-/- BM progenitor-derived monocytes, tissue macrophages and lung DCs showed a repopulation advantage over those derived from wild-type (WT) BM progenitors, suggesting enhanced CSF1R signaling in the absence of iRhom2. In vitro experiments indicate that iRhom2-/- Lin - SCA-1 + c-Kit + (LSKs) cells, but not granulocyte-macrophage progenitors (GMPs), had faster growth rates than WT cells in response to CSF1. Our results shed light on an important role of iRhom2/ADAM17 pathway in regulation of CSF1R shedding and repopulation of monocytes, macrophages and DCs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

iRhom2 regulates cell surface expression of CSF1R and non-steady state myelopoiesis in mice

PubMed Central

Qing, Xiaoping; Lavin, Yonit; Redecha, Patricia; Issuree, Priya D.; Maretzky, Thorsten; Merad, Miriam; McIlwain, David; Mak, Tak W.; Overall, Christopher M.

2016-01-01

The colony stimulating factor 1 receptor (CSF1R) functions as the major receptor for macrophage colony stimulating factor (CSF1) with crucial roles in regulating myelopoeisis. CSF1R can be proteolytically released from the cell surface by A disintegrin and metalloprotease 17 (ADAM17). Here we identified CSF1R as a major substrate of ADAM17 in an unbiased degradomics screen. We explored the impact of CSF1R shedding by ADAM17 and its upstream regulator, inactive rhomboid protein 2 (iRhom2, gene name Rhbdf2), on homeostatic development of mouse myeloid cells. In iRhom2−/− mice, we found constitutive accumulation of membrane-bound CSF1R on myeloid cells at steady state, although cell numbers of these populations were not altered. However, in the context of mixed bone marrow (BM) chimera, under competitive pressure, iRhom2−/− BM progenitor-derived monocytes, tissue macrophages and lung DCs showed a repopulation advantage over those derived from wild type (WT) BM progenitors, suggesting enhanced CSF1R signaling in the absence of iRhom2. In vitro experiments indicate that iRhom2−/− Lin−SCA-1+c-Kit+ (LSKs) cells, but not granulocyte-macrophage progenitors (GMPs), had faster growth rates than WT cells in response to CSF1. Our results shed light on an important role of iRhom2/ADAM17 pathway in regulation of CSF1R shedding and repopulation of monocytes, macrophages and DCs. PMID:27601030

Modulating glioma-mediated myeloid-derived suppressor cell development with sulforaphane

PubMed Central

Kumar, Ravi; de Mooij, Tristan; Peterson, Timothy E.; Kaptzan, Tatiana; Johnson, Aaron J.; Daniels, David J.; Parney, Ian F.

2017-01-01

Glioblastoma is the most common primary tumor of the brain and has few long-term survivors. The local and systemic immunosuppressive environment created by glioblastoma allows it to evade immunosurveillance. Myeloid-derived suppressor cells (MDSCs) are a critical component of this immunosuppression. Understanding mechanisms of MDSC formation and function are key to developing effective immunotherapies. In this study, we developed a novel model to reliably generate human MDSCs from healthy-donor CD14+ monocytes by culture in human glioma-conditioned media. Monocytic MDSC frequency was assessed by flow cytometry and confocal microscopy. The resulting MDSCs robustly inhibited T cell proliferation. A cytokine array identified multiple components of the GCM potentially contributing to MDSC generation, including Monocyte Chemoattractive Protein-1, interleukin-6, interleukin-8, and Macrophage Migration Inhibitory Factor (MIF). Of these, Macrophage Migration Inhibitory Factor is a particularly attractive therapeutic target as sulforaphane, a naturally occurring MIF inhibitor derived from broccoli sprouts, has excellent oral bioavailability. Sulforaphane inhibits the transformation of normal monocytes to MDSCs by glioma-conditioned media in vitro at pharmacologically relevant concentrations that are non-toxic to normal leukocytes. This is associated with a corresponding increase in mature dendritic cells. Interestingly, sulforaphane treatment had similar pro-inflammatory effects on normal monocytes in fresh media but specifically increased immature dendritic cells. Thus, we have used a simple in vitro model system to identify a novel contributor to glioblastoma immunosuppression for which a natural inhibitor exists that increases mature dendritic cell development at the expense of myeloid-derived suppressor cells when normal monocytes are exposed to glioma conditioned media. PMID:28666020

Advanced glycation end products and their receptor contribute to ovarian ageing.

PubMed

Stensen, Mette Haug; Tanbo, Tom; Storeng, Ritsa; Fedorcsak, Peter

2014-01-01

Do advanced glycation end products (AGE) and the receptor for advanced glycation end products (RAGE) affect the cells of the human ovarian follicle? AGE accumulate on the surface of ovarian granulosa-lutein (GL) cells and monocytes by binding to RAGE and other receptors with possible functional effects on these cells. AGE and RAGE are expressed in granulosa and theca cells, as well as in luteinized cells derived from the ovary. In this prospective cohort study, human follicle fluid-derived cells were isolated from aspirates of ovarian follicles of women who underwent assisted reproduction treatment. Immunofluorescence microscopy and multi-colour flow cytometry were used to determine the presence of AGE and RAGE on the surface of follicular fluid-derived cells and to characterize downstream effects of RAGE activation. GL cells and ovarian monocytes were found to contain AGE and RAGE and to bind AGE-bovine serum albumin (BSA) in correlation with the patients' chronological age. AGE-BSA and BSA failed to induce significantly the cleavage of caspase-3, phosphorylation of nuclear factor-κB or the binding of annexin V (the latter was marginally increased). AGE-fibronectin was found to induce detachment of cultured GL cells in vitro. The impact of AGE and RAGE in the ovary, shown here in cells in culture, remains to be affirmed in clinical settings. The ligands of RAGE and their effects in the ovary remain uncertain but this study implies that AGEs in the form of structural long-lived extracellular matrix proteins, rather than soluble AGEs, may play a role in the decline of ovarian function during ageing. The project was funded by the Norwegian Resource Centre for Women's Health, Oslo University Hospital. The authors have no conflicts of interests.

Inflammatory response of a prostate stromal cell line induced by Trichomonas vaginalis.

PubMed

Im, S J; Han, I H; Kim, J H; Gu, N Y; Seo, M Y; Chung, Y H; Ryu, J S

2016-04-01

While Trichomonas vaginalis, a cause of sexually transmitted infection, is known as a surface-dwelling protozoa, trichomonads have been detected in prostatic tissue from benign prostatic hyperplasia and prostatitis by immunoperoxidase assay or PCR. However, the immune response of prostate stromal cells infected with T. vaginalis has not been investigated. Our objective was to investigate whether T. vaginalis could induce an inflammatory response in prostate stromal cells. Incubation of a human prostate stromal myofibroblast cells (WPMY-1) with live T. vaginalis T016 increased expression of the inflammatory chemokines CXCL8 and CCL2. In addition, TLR4, ROS, MAPK and NF-κB expression increased, while inhibitors of TLR4, ROS, MAPKs and NF-κB reduced CXCL8 and CCL2 production. Medium conditioned by incubation of WPMY-1 cells with T. vaginalis stimulated the migration of human neutrophils and monocytes (THP-1 cells). We conclude that T. vaginalis increases CXCL8 and CCL2 production by human prostate stromal cells by activating TLR4, ROS, MAPKs and NF-κB, and this in turn attracts neutrophils and monocytes and leads to an inflammatory response. This study is the first attempt to demonstrate an inflammatory reaction in prostate stromal cells caused by T. vaginalis. © 2016 John Wiley & Sons Ltd.

CXCL4-induced monocyte survival, cytokine expression, and oxygen radical formation is regulated by sphingosine kinase 1.

PubMed

Kasper, Brigitte; Winoto-Morbach, Supandi; Mittelstädt, Jessica; Brandt, Ernst; Schütze, Stefan; Petersen, Frank

2010-04-01

Human monocytes respond to a variety of stimuli with a complex spectrum of activities ranging from acute defense mechanisms to cell differentiation or cytokine release. However, the individual intracellular signaling pathways related to these functions are not well understood. CXC chemokine ligand 4 (CXCL4) represents a broad activator of monocytes, which induces acute as well as delayed activities in these cells including cell differentiation, survival, or the release of ROS, and cytokines. Here, we report for the first time that CXCL4-treated monocytes significantly upregulate sphingosine kinase 1 (SphK1) mRNA and that CXCL4 induces SphK1 enzyme activity as well as its translocation to the cell membrane. Furthermore, we could show that pharmacological inhibition of SphK results in reversal of CXCL4-induced monocyte survival, cytokine expression, and release of oxygen radicals, which was confirmed by the use of SphK1-specific siRNA. CXCL4-mediated rescue from apoptosis, which is accompanied by inhibition of caspases, is controlled by SphK1 and its downstream element Erk. Taken together, these data assign SphK1 as a central regulator of acute and delayed monocyte activation and suggest SphK1 as a potential therapeutic target to suppress pro-inflammatory responses induced by CXCL4.

Potential proinflammatory effects of hydroxyapatite nanoparticles on endothelial cells in a monocyte–endothelial cell coculture model

PubMed Central

Liu, Xin; Sun, Jiao

2014-01-01

Currently, synthetic hydroxyapatite nanoparticles (HANPs) are used in nanomedicine fields. The delivery of nanomedicine to the bloodstream exposes the cardiovascular system to a potential threat. However, the possible adverse cardiovascular effects of HANPs remain unclear. Current observations using coculture models of endothelial cells and monocytes with HANPs to mimic the complex physiological functionality of the vascular system demonstrate that monocytes could play an important role in the mechanisms of endothelium dysfunction induced by the exposure to HANPs. Our transmission electron microscopy analysis revealed that both monocytes and endothelial cells could take up HANPs. Moreover, our findings demonstrated that at a subcytotoxic dose, HANPs alone did not cause direct endothelial cell injury, but they did induce an indirect activation of endothelial cells, resulting in increased interleukin-6 production and elevated adhesion molecule expression after coculture with monocytes. The potential proinflammatory effect of HANPs is largely mediated by the release of soluble factors from the activated monocytes, leading to an inflammatory response of the endothelium, which is possibly dependent on p38/c-Jun N-terminal kinase, and nuclear factor-kappa B signaling activation. The use of in vitro monocyte–endothelial cell coculture models for the biocompatibility assessment of HANPs could reveal their potential proinflammatory effects on endothelial cells, suggesting that exposure to HANPs possibly increases the risk of cardiovascular disease. PMID:24648726

Single-cell systems level analysis of human Toll-Like-Receptor activation defines a chemokine signature in Systemic Lupus Erythematosus

PubMed Central

O'Gorman, William E.; Hsieh, Elena W.Y.; Savig, Erica S.; Gherardini, Pier Federico; Hernandez, Joseph D.; Hansmann, Leo; Balboni, Imelda M.; Utz, Paul J.; Bendall, Sean C.; Fantl, Wendy J.; Lewis, David B.; Nolan, Garry P.; Davis, Mark M.

2015-01-01

Background Activation of Toll-Like Receptors (TLRs) induces inflammatory responses involved in immunity to pathogens and autoimmune pathogenesis, such as in Systemic Lupus Erythematosus (SLE). Although TLRs are differentially expressed across the immune system, a comprehensive analysis of how multiple immune cell subsets respond in a system-wide manner has previously not been described. Objective To characterize TLR activation across multiple immune cell subsets and individuals, with the goal of establishing a reference framework against which to compare pathological processes. Methods Peripheral whole blood samples were stimulated with TLR ligands, and analyzed by mass cytometry simultaneously for surface marker expression, activation states of intracellular signaling proteins, and cytokine production. We developed a novel data visualization tool to provide an integrated view of TLR signaling networks with single-cell resolution. We studied seventeen healthy volunteer donors and eight newly diagnosed untreated SLE patients. Results Our data revealed the diversity of TLR-induced responses within cell types, with TLR ligand specificity. Subsets of NK and T cells selectively induced NF-κB in response to TLR2 ligands. CD14hi monocytes exhibited the most polyfunctional cytokine expression patterns, with over 80 distinct cytokine combinations. Monocytic TLR-induced cytokine patterns were shared amongst a group of healthy donors, with minimal intra- and inter- individual variability. Furthermore, autoimmune disease altered baseline cytokine production, as newly diagnosed untreated SLE patients shared a distinct monocytic chemokine signature, despite clinical heterogeneity. Conclusion Mass cytometry analysis defined a systems-level reference framework for human TLR activation, which can be applied to study perturbations in inflammatory disease, such as SLE. PMID:26037552

The chemokine receptor CX3CR1 coordinates monocyte recruitment and endothelial regeneration after arterial injury.

PubMed

Getzin, Tobias; Krishnasamy, Kashyap; Gamrekelashvili, Jaba; Kapanadze, Tamar; Limbourg, Anne; Häger, Christine; Napp, L Christian; Bauersachs, Johann; Haller, Hermann; Limbourg, Florian P

2018-02-01

Regeneration of arterial endothelium after injury is critical for the maintenance of normal blood flow, cell trafficking, and vascular function. Using mouse models of carotid injury, we show that the transition from a static to a dynamic phase of endothelial regeneration is marked by a strong increase in endothelial proliferation, which is accompanied by induction of the chemokine CX 3 CL1 in endothelial cells near the wound edge, leading to progressive recruitment of Ly6C lo monocytes expressing high levels of the cognate CX 3 CR1 chemokine receptor. In Cx3cr1 -deficient mice recruitment of Ly6C lo monocytes, endothelial proliferation and regeneration of the endothelial monolayer after carotid injury are impaired, which is rescued by acute transfer of normal Ly6C lo monocytes. Furthermore, human non-classical monocytes induce proliferation of endothelial cells in co-culture experiments in a VEGFA-dependent manner, and monocyte transfer following carotid injury promotes endothelial wound closure in a hybrid mouse model in vivo Thus, CX 3 CR1 coordinates recruitment of specific monocyte subsets to sites of endothelial regeneration, which promote endothelial proliferation and arterial regeneration. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

The modulatory effects of caffeic acid on human monocytes and its involvement in propolis action.

PubMed

Búfalo, Michelle Cristiane; Sforcin, José Maurício

2015-05-01

Researchers have been interested in investigating the mechanisms of action of propolis and the compounds involved in its biological activity; however, the effect of its isolated constituents on human immune cells still deserves investigation. Thus, this study aimed to verify the action of caffeic acid on human monocytes in an attempt to verify its effects on the innate immunity, and to analyse its participation in propolis activity. Monocytes viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method after incubation with caffeic acid. Cell markers expression by monocytes (Toll-like receptors (TLR)-2, TLR-4, human leukocyte antigen (HLA)-DR and CD80) was analysed by flow cytometry. TNF-α and IL-10 production was determined by enzyme-linked immunosorbent assay and the activity of monocytes against Candida albicans was investigated after incubation with different concentrations of caffeic acid. Caffeic acid downregulated TLR-2 and HLA-DR expression and inhibited cytokine production whereas it upregulated the fungicidal activity of monocytes, without affecting cell viability. Caffeic acid exerted an immunomodulatory action in human monocytes in the evaluated parameters depending on concentration, with no cytotoxic effects. Moreover, it was partially involved in propolis action. © 2015 Royal Pharmaceutical Society.

Proteomics show antigen presentation processes in human immune cells after AS03-H5N1 vaccination.

PubMed

Galassie, Allison C; Goll, Johannes B; Samir, Parimal; Jensen, Travis L; Hoek, Kristen L; Howard, Leigh M; Allos, Tara M; Niu, Xinnan; Gordy, Laura E; Creech, C Buddy; Hill, Heather; Joyce, Sebastian; Edwards, Kathryn M; Link, Andrew J

2017-06-01

Adjuvants enhance immunity elicited by vaccines through mechanisms that are poorly understood. Using a systems biology approach, we investigated temporal protein expression changes in five primary human immune cell populations: neutrophils, monocytes, natural killer cells, T cells, and B cells after administration of either an Adjuvant System 03 adjuvanted or unadjuvanted split-virus H5N1 influenza vaccine. Monocytes demonstrated the strongest differential signal between vaccine groups. On day 3 post-vaccination, several antigen presentation-related pathways, including MHC class I-mediated antigen processing and presentation, were enriched in monocytes and neutrophils and expression of HLA class I proteins was increased in the Adjuvant System 03 group. We identified several protein families whose proteomic responses predicted seroprotective antibody responses (>1:40 hemagglutination inhibition titer), including inflammation and oxidative stress proteins at day 1 as well as immunoproteasome subunit (PSME1 and PSME2) and HLA class I proteins at day 3 in monocytes. While comparison between temporal proteomic and transcriptomic results showed little overlap overall, enrichment of the MHC class I antigen processing and presentation pathway in monocytes and neutrophils was confirmed by both approaches. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

TLR10 suppresses the activation and differentiation of monocytes with effects on DC-mediated adaptive immune responses

PubMed Central

Hess, Nicholas J.; Felicelli, Christopher; Grage, Jennifer; Tapping, Richard I.

2017-01-01

TLRs are important pattern-recognition receptors involved in the activation of innate immune responses against foreign pathogens. TLR10 is the only TLR family member without a known ligand, signaling pathway, or clear cellular function. Previous work has shown that TLR10 suppresses proinflammatory cytokine production in response to TLR agonists in a mixed human mononuclear cell population. We report that TLR10 is preferentially expressed on monocytes and suppresses proinflammatory cytokine production resulting from either TLR or CD40 stimulation. TLR10 engagement affects both the MAPK and Akt signaling pathways, leading to changes in the transcriptome of isolated human monocytes. Differentiation of monocytes into dendritic cells in the presence of an αTLR10 mAb reduced the expression of maturation markers and the induction of proinflammatory cytokines, again in response to either TLR or CD40 stimulation. Finally, in coculture experiments, TLR10 differentiated dendritic cells exhibited a decreased capacity to activate T cells as measured by IL-2 and IFN-γ production. These data demonstrate that TLR10 is a novel regulator of innate immune responses and of the differentiation of primary human monocytes into effective dendritic cells. PMID:28235773

The Human Cytomegalovirus Lytic Cycle Is Induced by 1,25-Dihydroxyvitamin D3 in Peripheral Blood Monocytes and in the THP-1 Monocytic Cell Line

PubMed Central

Wu, Shu-En; Miller, William E.

2015-01-01

Human cytomegalovirus (HCMV) resides in a latent form in hematopoietic progenitors and undifferentiated cells within the myeloid lineage. Maturation and differentiation along the myeloid lineage triggers lytic replication. Here, we used peripheral blood monocytes and the monocytic cell line THP-1 to investigate the effects of 1,25-dihydroxyvitamin D3 on HCMV replication. Interestingly, 1,25-dihydroxyvitamin D3 induces lytic replication marked by upregulation of HCMV gene expression and production of infectious virus. Moreover, we demonstrate that the effects of 1,25-dihydroxyvitamin D3 correlate with maturation/differentiation of the monocytes and not by directly stimulating the MIEP. These results are somewhat surprising as 1,25-dihydroxyvitamin D3 typically boosts immunity to bacteria and viruses rather than driving the infectious life cycle as it does for HCMV. Defining the signaling pathways kindled by 1,25-dihydroxyvitamin D3 will lead to a better understanding of the underlying molecular mechanisms that determine the fate of HCMV once it infects cells in the myeloid lineage. PMID:25965798

Analysis of circulating CD14+/CD16+ monocyte-derived macrophages (MDMs) in the peripheral blood of patients with oral squamous cell carcinoma.

PubMed

Grimm, Martin; Feyen, Oliver; Coy, Johannes F; Hofmann, Heiko; Teriete, Peter; Reinert, Siegmar

2016-03-01

Monocytes/macrophages are regarded as the first line of defense in tumors. Therefore, analyzing monocyte subtypes in oral squamous cell carcinoma (OSCC) may be of value in disease monitoring and to explore immunotherapeutic strategies for cancer patients. Circulating peripheral blood CD14+/CD16+ monocyte-derived macrophages (MDMs) were evaluated in OSCC patients with oral squamous cell carcinoma (n = 44) compared with controls (n = 85). Moreover, epitope detection in monocytes (EDIM) technology was used to detect biomarkers Apo10 and transketolase-like-1 in CD14+/CD16+ MDMs. Compared with controls, no significant (P = .3646) difference (control group 9.8%, OSCC group 8.8%) in CD14+/CD16+ MDM were noted in OSCC. However, EDIM-Apo10 and EDIM-TKTL1 scores detected in the CD14+/CD16+ MDMs were increased in OSCC compared with controls (P < .0001). Analyzing CD14+/CD16+ MDMs represents a stable cell population for detecting biomarkers in cancer disease monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

Global analysis of glycoproteins identifies markers of endotoxin tolerant monocytes and GPR84 as a modulator of TNFα expression.

PubMed

Müller, Mario M; Lehmann, Roland; Klassert, Tilman E; Reifenstein, Stella; Conrad, Theresia; Moore, Christoph; Kuhn, Anna; Behnert, Andrea; Guthke, Reinhard; Driesch, Dominik; Slevogt, Hortense

2017-04-12

Exposure of human monocytes to lipopolysaccharide (LPS) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance. In this study, we investigated the LPS-induced global glycoprotein expression changes of tolerant human monocytes and THP-1 cells to identify markers and glycoprotein targets capable to modulate the immunosuppressive state. Using hydrazide chemistry and LC-MS/MS analysis, we analyzed glycoprotein expression changes during a 48 h LPS time course. The cellular snapshots at different time points identified 1491 glycoproteins expressed by monocytes and THP-1 cells. Label-free quantitative analysis revealed transient or long-lasting LPS-induced expression changes of secreted or membrane-anchored glycoproteins derived from intracellular membrane coated organelles or from the plasma membrane. Monocytes and THP-1 cells demonstrated marked differences in glycoproteins differentially expressed in the tolerant state. Among the shared differentially expressed glycoproteins G protein-coupled receptor 84 (GPR84) was identified as being capable of modulating pro-inflammatory TNFα mRNA expression in the tolerant cell state when activated with its ligand Decanoic acid.

Mechanisms of Cytotoxicity of the AIDS Virus.

DTIC Science & Technology

1991-10-10

lentiviruses causes immunosuppression in cats ( feline immunodeficiency virus) (Pederson et al., 1987; Luciw et al., 1989), sheep (visna virus) (Haas et...determinant within the human immunodeficiency virus 1 surface envelope glycoprotein critical for productive infection of primary monocytes. 4. Simian... Immunodeficiency Virus Negative Factor Suppresses the Level of Viral mRNA in COS cells 5. Protein N-myristoylation/AIDS/fatty acid analogs 6. Functional

Patients with the worst outcomes after paracetamol (acetaminophen)-induced liver failure have an early monocytopenia.

PubMed

Moore, J K; MacKinnon, A C; Man, T Y; Manning, J R; Forbes, S J; Simpson, K J

2017-02-01

Acute liver failure (ALF) is associated with significant morbidity and mortality. Studies have implicated the immune response, especially monocyte/macrophages as being important in dictating outcome. To investigate changes in the circulating monocytes and other immune cells serially in patients with ALF, relate these with cytokine concentrations, monocyte gene expression and patient outcome. In a prospective case-control study in the Scottish Liver Transplant Unit, Royal Infirmary Edinburgh, 35 consecutive patients admitted with paracetamol-induced liver failure (POD-ALF), 10 patients with non-paracetamol causes of ALF and 16 controls were recruited. The peripheral blood monocyte phenotype was analysed by flow cytometry, circulating cytokines quantified by protein array and monocyte gene expression array performed and related to outcome. On admission, patients with worst outcomes after POD-ALF had a significant monocytopenia, characterised by reduced classical and expanded intermediate monocyte population. This was associated with reduced circulating lymphocytes and natural killer cells, peripheral cytokine patterns suggestive of a 'cytokine storm' and increased concentrations of cytokines associated with monocyte egress from the bone marrow. Gene expression array did not differentiate patient outcome. At day 4, there was no significant difference in monocyte, lymphocyte or natural killer cells between survivors and the patients with adverse outcomes. Severe paracetamol liver failure is associated with profound changes in the peripheral blood compartment, particularly in monocytes, related with worse outcomes. This is not seen in patients with non-paracetamol-induced liver failure. Significant monocytopenia on admission may allow earlier clarification of prognosis, and it highlights a potential target for therapeutic intervention. © 2016 John Wiley & Sons Ltd.

Triglyceride-rich lipoprotein regulates APOB48 receptor gene expression in human THP-1 monocytes and macrophages.

PubMed

Bermudez, Beatriz; Lopez, Sergio; Varela, Lourdes M; Ortega, Almudena; Pacheco, Yolanda M; Moreda, Wenceslao; Moreno-Luna, Rafael; Abia, Rocio; Muriana, Francisco J G

2012-02-01

The postprandial metabolism of dietary fats implies that the production of TG-rich lipoproteins (TRL) contributes to the progression of plaque development. TRL and their remnants cause rapid receptor-mediated monocyte/macrophage lipid engorgement via the cell surface apoB48 receptor (apoB48R). However, the mechanistic basis for apoB48 receptor (APOB48R) regulation by postprandial TRL in monocytes and macrophages is not well established. In this study, we investigated the effects of postprandial TRL from healthy volunteers on the expression of APOB48R mRNA and lipid uptake in human THP-1 monocytes and THP-1-derived macrophages. The expression of APOB48R mRNA was upregulated in THP-1 monocytes, but downregulated in THP-1-derived macrophages when treated with postprandial TRL (P < 0.05), in a dose- and time-dependent manner. TG and free cholesterol were dramatically increased in THP-1-derived macrophages (140 and 50%, respectively; P < 0.05) and in THP-1 monocytes (160 and 95%, respectively; P < 0.05). This lipid accumulation was severely decreased (~50%; P < 0.05) in THP-1-derived macrophages by small interfering RNA (siRNA) targeting of APOB48R. Using PPAR and retinoid X receptor (RXR) agonists, antagonists, and siRNA, our data indicate that PPARα, PPARγ, and RXRα are involved in postprandial TRL-induced APOB48R transcriptional regulation. Co-incubation with acyl-CoA synthetase or acyl-CoA:cholesterol acyltransferase inhibitors potentiated the effects of postprandial TRL on the expression of APOB48R mRNA in THP-1 monocytes and THP-1-derived macrophages. Our findings collectively suggest that APOB48R represents a molecular target of postprandial TRL via PPAR-dependent pathways in human THP-1 monocytes and macrophages and advance a potentially important link between postprandial metabolism of dietary fats and atherogenesis.

S100A8/A9 increases the mobilization of pro-inflammatory Ly6Chigh monocytes to the synovium during experimental osteoarthritis.

PubMed

Cremers, Niels A J; van den Bosch, Martijn H J; van Dalen, Stephanie; Di Ceglie, Irene; Ascone, Giuliana; van de Loo, Fons; Koenders, Marije; van der Kraan, Peter; Sloetjes, Annet; Vogl, Thomas; Roth, Johannes; Geven, Edwin J W; Blom, Arjen B; van Lent, Peter L E M

2017-09-29

Monocytes are dominant cells present within the inflamed synovium during osteoarthritis (OA). In mice, two functionally distinct monocyte subsets are described: pro-inflammatory Ly6C high and patrolling Ly6C low monocytes. Alarmins S100A8/A9 locally released by the synovium during inflammatory OA for prolonged periods may be dominant proteins involved in stimulating recruitment of Ly6C high monocytes from the circulation to the joint. Our objective was to investigate the role of S100A8/A9 in the mobilization of Ly6C high and Ly6C low monocytic populations to the inflamed joint in collagenase-induced OA (CiOA). S100A8 was injected intra-articularly to investigate monocyte influx. CiOA was induced by injection of collagenase into knee joints of wild-type C57BL/6 (WT), and S100a9 -/- mice. Mice were sacrificed together with age-matched saline-injected control mice (n = 6/group), and expression of monocyte markers, pro-inflammatory cytokines, and chemokines was determined in the synovium using ELISA and RT-qPCR. Cells were isolated from the bone marrow (BM), spleen, blood, and synovium and monocytes were identified using FACS. S100A8/A9 was highly expressed during CiOA. Intra-articular injection of S100A8 leads to elevated expression of monocyte markers and the monocyte-attracting chemokines CCL2 and CX3CL1 in the synovium. At day 7 (d7) after CiOA induction in WT mice, numbers of Ly6C high , but not Ly6C low monocytes, were strongly increased (7.6-fold) in the synovium compared to saline-injected controls. This coincided with strong upregulation of CCL2, which preferentially attracts Ly6C high monocytes. In contrast, S100a9 -/- mice showed a significant increase in Ly6C low monocytes (twofold) within the synovium at CiOA d7, whereas the number of Ly6C high monocytes remained unaffected. In agreement with this finding, the Ly6C low mobilization marker CX3CL1 was significantly higher within the synovium of S100a9 -/- mice. Next, we studied the effect of S100A8/A9 on release of Ly6C high monocytes from the BM into the circulation. A 14% decrease in myeloid cells was found in WT BM at CiOA d7. No decrease in myeloid cells in S100a9 -/- BM was found, suggesting that S100A8/A9 promotes the release of myeloid populations from the BM. Induction of OA locally leads to strongly elevated S100A8/A9 expression and an elevated influx of Ly6C high monocytes from the BM to the synovium.

Zinc oxide nanoparticles induce migration and adhesion of monocytes to endothelial cells and accelerate foam cell formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suzuki, Yuka; Tada-Oikawa, Saeko; Ichihara, Gaku

Metal oxide nanoparticles are widely used in industry, cosmetics, and biomedicine. However, the effects of exposure to these nanoparticles on the cardiovascular system remain unknown. The present study investigated the effects of nanosized TiO{sub 2} and ZnO particles on the migration and adhesion of monocytes, which are essential processes in atherosclerogenesis, using an in vitro set-up of human umbilical vein endothelial cells (HUVECs) and human monocytic leukemia cells (THP-1). We also examined the effects of exposure to nanosized metal oxide particles on macrophage cholesterol uptake and foam cell formation. The 16-hour exposure to ZnO particles increased the level of monocytemore » chemotactic protein-1 (MCP-1) and induced the migration of THP-1 monocyte mediated by increased MCP-1. Exposure to ZnO particles also induced adhesion of THP-1 cells to HUVECs. Moreover, exposure to ZnO particles, but not TiO{sub 2} particles, upregulated the expression of membrane scavenger receptors of modified LDL and increased cholesterol uptake in THP-1 monocytes/macrophages. In the present study, we found that exposure to ZnO particles increased macrophage cholesterol uptake, which was mediated by an upregulation of membrane scavenger receptors of modified LDL. These results suggest that nanosized ZnO particles could potentially enhance atherosclerogenesis and accelerate foam cell formation. - Highlights: • Effects of metal oxide nanoparticles on foam cell formation were investigated. • Exposure to ZnO nanoparticles induced migration and adhesion of monocytes. • Exposure to ZnO nanoparticles increased macrophage cholesterol uptake. • Expression of membrane scavenger receptors of modified LDL was also increased. • These effects were not observed after exposure to TiO{sub 2} nanoparticles.« less

Innate immune responses of equine monocytes cultured in equine platelet lysate.

PubMed

Naskou, Maria C; Norton, Natalie A; Copland, Ian B; Galipeau, Jacques; Peroni, John F

2018-01-01

Platelet lysate (PL) has been extensively used for the laboratory expansion of human mesenchymal stem cells (MSC) in order to avoid fetal bovine serum (FBS) which has been associated with immune-mediated host reactions and transmission of bovine-origin microbial contaminants. Before suggesting the routine use of PL for MSC culture, we wanted to further investigate whether PL alone might trigger inflammatory responses when exposed to reactive white blood cells such as monocytes. Our objectives were to evaluate the inflammatory profile of equine monocytes cultured with equine PL (ePL) and to determine if ePL can modulate the expression of inflammatory cytokines in lipopolysaccharide (LPS)-stimulated monocytes. In a first experiment, equine monocytes were isolated and incubated with donor horse serum (DHS), FBS, six individual donors ePL or pooled ePL from all horses. In a second experiment, monocytes were stimulated with E. coli LPS in the presence of 1, 5 or 10% DHS and/or pooled ePL. After 6h of incubation, cell culture supernatants were assayed via ELISA for production of the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and Interleukin 1β (IL-1β) as well as for the anti-inflammatory Interleukin 10 (IL-10). Equine monocytes incubated with pooled ePL produced significantly less TNF-α and significantly more IL-10 than monocytes incubated in FBS. A statistically significant difference was not identified for the production of IL-1β. The second experiment showed that pooled ePL added to LPS-stimulated equine monocytes resulted in a significant reduction in TNF-α and IL-1β production. IL-10 production was not significantly upregulated by the addition of ePL to LPS-stimulated monocytes. Finally, the addition of ePL to LPS-stimulated monocytes in the presence of various concentrations of DHS resulted to statistically significant decrease of TNF-α and IL-1β compared to the control groups. This is the first study to demonstrate that ePL suppresses the release of pro-inflammatory cytokines from stimulated equine monocytes. These results encourage further exploration of PL as a homologous media substitute for FBS but also opens the possibility of investigating its use as means to suppress cell-mediated inflammation. Published by Elsevier B.V.

Oscillatory shear stress stimulates endothelial production of O2- from p47phox-dependent NAD(P)H oxidases, leading to monocyte adhesion

NASA Technical Reports Server (NTRS)

Hwang, Jinah; Saha, Aniket; Boo, Yong Chool; Sorescu, George P.; McNally, J. Scott; Holland, Steven M.; Dikalov, Sergei; Giddens, Don P.; Griendling, Kathy K.; Harrison, David G.;

Real-time imaging of Toxoplasma-infected human monocytes under fluidic shear stress reveals rapid translocation of intracellular parasites across endothelial barriers

PubMed Central

Ueno, Norikiyo; Harker, Katherine S.; Clarke, Elizabeth V.; McWhorter, Frances Y.; Liu, Wendy F.; Tenner, Andrea J.; Lodoen, Melissa B.

2014-01-01

Summary Peripheral blood monocytes are actively infected by Toxoplasma gondii and can function as “Trojan horses” for parasite spread in the bloodstream. Using dynamic live-cell imaging, we visualized the transendothelial migration (TEM) of T. gondii-infected primary human monocytes during the initial minutes following contact with human endothelium. On average, infected and uninfected monocytes required only 9.8 and 4.1 minutes, respectively, to complete TEM. Infection increased monocyte crawling distances and velocities on endothelium, but overall TEM frequencies were comparable between infected and uninfected cells. In the vasculature, monocytes adhere to endothelium under the conditions of shear stress found in rapidly flowing blood. Remarkably, the addition of fluidic shear stress increased the TEM frequency of infected monocytes 4.5-fold compared to static conditions (to 45.2% from 10.3%). Infection led to a modest increase in expression of the high affinity conformation of the monocyte integrin Mac-1, and Mac-1 accumulated near endothelial junctions during TEM. Blocking Mac-1 inhibited the crawling and TEM of infected monocytes to a greater degree than uninfected monocytes, and blocking the Mac-1 ligand, ICAM-1, dramatically reduced crawling and TEM for both populations. These findings contribute to a greater understanding of parasite dissemination from the vasculature into tissues. PMID:24245749

1,25-DIHYDROXYVITAMIN D3 INDUCES MONOCYTIC DIFFERENTIATION OF HUMAN MYELOID LEUKEMIA CELLS BY REGULATING C/EBPβ EXPRESSION THROUGH MEF2C

PubMed Central

Zheng, Ruifang; Wang, Xuening; Studzinski, George P.

2015-01-01

Myogenic enhancer factor2 (Mef2) consists of a family of transcription factors involved in morphogenesis of skeletal, cardiac and smooth muscle cells. Among the four isoforms (Mef2A, 2B, 2C, and 2D), Mef2C was also found to play important roles in hematopoiesis. At myeloid progenitor level, Mef2C expression favors monocytic differentiation. Previous studies from our laboratory demonstrated that ERK5 was activated in 1,25-dihydroxyvitamin D3 (1,25D)-induced monocytic differentiation in AML cells and ERK5 activation was accompanied by increased Mef2C phosphorylation. We therefore examined the role of Mef2C in 1,25D-induced monocytic differentiation in AML cell lines (HL60, U937 and THP1) and found that knockdown of Mef2C with small interfering RNA (siRNA) significantly decreases the expression of the monocytic marker, CD14, without affecting the expression of the general myeloid marker, CD11b. CCAAT/Enhancer-binding protein (C/EBP) β, which can bind to CD14 promoter and increase its transcription, has been shown to be the downstream effector of 1,25D-induced monocytic differentiation in AML cells. When Mef2C was knocked down, expression of C/EBPβ was reduced at both mRNA and protein levels. The protein expression levels of cell cycle regulators, p27Kip1 and cyclin D1, were not affected by Mef2C knockdown, nor the monopoiesis related transcription factor, ATF2 (Activating Transcription Factor 2). Thus, we conclude that 1,25D-induced monocytic differentiation, and CD14 expression in particular, is mediated through activation of ERK5-Mef2C-C/EBPβ signaling pathway, and that Mef2C does not seem to modulate cell cycle progression. PMID:25448741

Human iNKT cells induce IL-1β secretion by peripheral blood monocytes via a P2X7-independent pathway

PubMed Central

Felley, Laura E.; Sharma, Akshat; Theisen, Erin; Romero-Masters, James C.; Sauer, John-Demian; Gumperz, Jenny E.

2016-01-01

The cytokine IL-1β plays a central role in inflammatory responses that are initiated by microbial challenges, as well as in those that are due to endogenous processes (often called “sterile” inflammation). IL-1β secretion that occurs independently of microbial stimulation is typically associated with the presence of endogenous alarmins, such as extracellular ATP (an indicator of cytopathic damage). Here we show that IL-2 activated human iNKT cells stimulate the secretion of IL-1β protein by human peripheral blood monocytes in a manner that requires neither the presence of microbial compounds nor signaling through the extracellular ATP receptor P2X7. Monocyte IL-1β production was specifically induced by iNKT cells, since similarly activated polyclonal autologous T cells did not have this effect. Secretion of IL-1β protein occurred rapidly (within 3-4 hours), and required cell contact between the iNKT cells and monocytes. Similar to IL-1β production induced by TLR stimulation, the iNKT-induced pathway appeared to entail a two-step process involving NFκB signaling and IL1B gene transcription, as well as assembly of the NLRP3 inflammasome and activation of caspase 1. However, in contrast to the classical inflammasome-mediated pathway of IL-1β production, activation of monocytes via P2X7 was dispensable for iNKT-induced IL-1β secretion and potassium efflux was not required. Moreover, the iNKT-induced effect involved caspase 8 activity, yet induced little monocyte death. These results suggest that IL-2 activated human iNKT cells induce monocytes to produce IL-1β through a distinctive pathway that does not require the presence of microbial danger signals or alarmins associated with cytopathic damage. PMID:27534556

Tim-3-expressing macrophages are functionally suppressed and expanded in oral squamous cell carcinoma due to virus-induced Gal-9 expression.

PubMed

Dong, Jianfeng; Cheng, Lijun; Zhao, Minchao; Pan, Xiangfeng; Feng, Zhiqiang; Wang, Dawei

2017-05-01

Oropharyngeal head and neck squamous cell carcinoma is a common malignant tumor in the oral cavity. High-risk human papillomavirus 16 infection is a major cause of oropharyngeal head and neck squamous cell carcinoma development. Strong antitumor immune responses, especially CD8 + T cell responses, are thought to be essential to effective cancer treatment and are associated with better prognosis in oropharyngeal head and neck squamous cell carcinoma. In this study, we examined the role of the Tim-3/Gal-9 pathway in oropharyngeal head and neck squamous cell carcinoma patients. We found that Gal-9 expression by CD4 + T cells was increased in human papillomavirus-positive oropharyngeal head and neck squamous cell carcinoma patients, but not in human papillomavirus-negative oropharyngeal head and neck squamous cell carcinoma patients. Increased Gal-9 secretion by CD4 + T cells presented multiple immunosuppressive effects. Coculturing monocytes with high Gal-9-expressing CD4 + T cells resulted in the expansion of Tim-3 + monocytes, which suppressed interferon gamma production by activated CD8 + T cells. Subsequently, total monocytes incubated with exogenous Gal-9, or high Gal-9-expressing CD4 + T cells, suppressed the expression of interferon gamma by CD8 + T cells. Exogenous Gal-9 and high Gal-9-expressing CD4 + T cells also suppressed the secretion of both interleukin 10 and interleukin 12 by monocytes. These effects are Tim-3/Gal-9-dependent because blocking Tim-3 and/or Gal-9 could enhance the support of CD8 + T cell interferon gamma production and the interleukin 10 and interleukin 12 secretion by monocytes. Together, these data suggest that the high Tim-3 expression in monocytes could be utilized by tumor-promoting Gal-9 expression on CD4 + T cells. Immunotherapy in human papillomavirus-positive oropharyngeal head and neck squamous cell carcinoma patients therefore faces an additional challenge posed by Tim-3 and Gal-9 and likely requires the blockade of these molecules.

Amniotic membrane extract differentially regulates human peripheral blood T cell subsets, monocyte subpopulations and myeloid dendritic cells.

PubMed

Laranjeira, Paula; Duque, Marta; Vojtek, Martin; Inácio, Maria J; Silva, Isabel; Mamede, Ana C; Laranjo, Mafalda; Pedreiro, Susana; Carvalho, Maria J; Moura, Paulo; Abrantes, Ana M; Maia, Cláudio J; Domingues, Pedro; Domingues, Rosário; Martinho, António; Botelho, Maria F; Trindade, Hélder; Paiva, Artur

2018-03-26

The discovery of the immunoregulatory potential of human amniotic membrane (hAM) propelled several studies focusing on its application for the treatment of immunological disorders. However, there is little information regarding the effects of hAM on distinct activation and differentiation stages of immune cells. Here, we aim to investigate the effect of human amniotic membrane extract (hAME) on the pattern of cytokine production by T cells, monocytes and myeloid dendritic cells (mDCs). For this purpose, peripheral blood mononuclear cells (PBMCs) from eight healthy individuals were stimulated in vitro in the presence or absence of hAME. Mitogen-induced proliferation of PBMCs and cytokine production among the distinct T cell functional compartments, monocyte subpopulations and mDCs were evaluated. hAME displayed an anti-proliferative effect and decreased the frequency of T cells producing tumor necrosis factor (TNF)α, interferon (IFN)γ and interleukin (IL)-2, for all T cell functional compartments. The frequency of IL-17 and IL-9-producing T cells was also reduced. The inhibition of mRNA expression of granzyme B, perforin and NKG2D by CD8 + T cells and γδ T cells and the augment of FoxP3 and IL-10 in CD4 + T cells and IL-10 in regulatory T cells were also observed. Furthermore, hAME inhibited IFNγ-induced protein (IP)-10 expression by classical and non-classical monocytes, without hampering the production of TNFα and IL-6 by monocytes and mDCs. These results suggest that hAME exerts an anti-inflammatory effect on T cells, still at a different extent for distinct T cell functional compartments.

Inhibition of P2X Receptors Protects Human Monocytes against Damage by Leukotoxin from Aggregatibacter actinomycetemcomitans and α-Hemolysin from Escherichia coli

PubMed Central

Skals, Marianne

2016-01-01

α-Hemolysin (HlyA) from Escherichia coli and leukotoxin A (LtxA) from Aggregatibacter actinomycetemcomitans are important virulence factors in ascending urinary tract infections and aggressive periodontitis, respectively. The extracellular signaling molecule ATP is released immediately after insertion of the toxins into plasma membranes and, via P2X receptors, is essential for the erythrocyte damage inflicted by these toxins. Moreover, ATP signaling is required for the ensuing recognition and phagocytosis of damaged erythrocytes by the monocytic cell line THP-1. Here, we investigate how these toxins affect THP-1 monocyte function. We demonstrate that both toxins trigger early ATP release and a following increase in the intracellular Ca2+ concentration ([Ca2+]i) in THP-1 monocytes. The HlyA- and LtxA-induced [Ca2+]i response is diminished by the P2 receptor antagonist in a pattern that fits the functional P2 receptor expression in these cells. Both toxins are capable of lysing THP-1 cells, with LtxA being more aggressive. Either desensitization or blockage of P2X1, P2X4, or P2X7 receptors markedly reduces toxin-induced cytolysis. This pattern is paralleled in freshly isolated human monocytes from healthy volunteers. Interestingly, only a minor fraction of the toxin-damaged THP-1 monocytes eventually lyse. P2X7 receptor inhibition generally prevents cell damage, except from a distinct cell shrinkage that prevails in response to the toxins. Moreover, we find that preexposure to HlyA preserves the capacity of THP-1 monocytes to phagocytose damaged erythrocytes and may induce readiness to discriminate between damaged and healthy erythrocytes. These findings suggest a new pharmacological target for protecting monocytes during exposure to pore-forming cytolysins during infection or injury. PMID:27528275

Peritoneal fluid from endometriosis patients switches differentiation of monocytes from dendritic cells to macrophages.

PubMed

Na, Yong-Jin; Jin, Jun-O; Lee, Mi-Sook; Song, Min-Gyu; Lee, Kyu-Sup; Kwak, Jong-Young

2008-01-01

Immunological abnormalities of cell-mediated and humoral immunity might be associated with the pathogenesis of endometriosis. This study has examined the effects of peritoneal fluid obtained from patients with endometriosis (ePF) on the phenotypic characteristics of macrophages and dendritic cells (DCs) derived from monocytes. Monocytes were obtained from healthy young volunteers and cultured with ePF (n=12) or a control PF (cPF) (n=5) in the presence or absence of macrophage-colony stimulating factor (M-CSF) or IL-4 plus granulocyte macrophage-colony stimulating factor (GM-CSF). The ePF was demonstrated to increase expression levels of CD14 and CD64 on isolated monocytes in the presence or absence of M-CSF. Compared with cPF, addition of 10% ePF to GM-CSF plus IL-4-treated monocytes significantly down-regulated CD1a expression and up-regulated CD64 expression, but did not enhance expression levels of class II MHC. ePF had no effect, however, on tumor necrosis factor-alpha-induced maturation of DC. Levels of IL-6, IL-10 and M-CSF production were higher in ePF-treated than cPF-treated monocytes for both cell culture conditions with GM-CSF plus IL-4 and M-CSF. A neutralizing IL-6 antibody, but not an IL-10 antibody, abrogated the ePF-induced down-regulation of CD1a, up-regulation of CD64 and secretion of M-CSF. These results suggest that ePF favorably induces monocyte differentiation toward macrophages rather than DCs, and that this effect is mediated by IL-6. A reciprocal mode of cell differentiation between macrophages and DCs in response to ePF may be related to the pathogenesis of endometriosis.

Loss of CX3CR1 increases accumulation of inflammatory monocytes and promotes gliomagenesis

PubMed Central

Feng, Xi; Chen, Zhihong; Heinzmann, David; Rasmussen, Rikke Darling; Alvarez-Garcia, Virginia; Kim, Yeonghwan; Wang, Bingcheng; Tamagno, Ilaria; Zhou, Hao; Li, Xiaoxia; Kettenmann, Helmut; Ransohoff, Richard M.; Hambardzumyan, Dolores

2015-01-01

The most abundant populations of non-neoplastic cells in the glioblastoma (GBM) microenvironment are resident microglia, macrophages and infiltrating monocytes from the blood circulation. The mechanisms by which monocytes infiltrate into GBM, their fate following infiltration, and their role in GBM growth are not known. Here we tested the hypothesis that loss of the fractalkine receptor CX3CR1 in microglia and monocytes would affect gliomagenesis. Deletion of Cx3cr1 from the microenvironment resulted in increased tumor incidence and shorter survival times in glioma-bearing mice. Loss of Cx3cr1 did not affect accumulation of microglia/macrophages in peri-tumoral areas, but instead indirectly promoted the trafficking of CD11b+CD45hiCX3CR1lowLy-6ChiLy-6G−F4/80−/low circulating inflammatory monocytes into the CNS, resulting in their increased accumulation in the perivascular area. Cx3cr1-deficient microglia/macrophages and monocytes demonstrated upregulation of IL1β expression that was inversely proportional to Cx3cr1 gene dosage. The Proneural subgroup of the TCGA GBM patient dataset with high IL1β expression showed shorter survival compared to patients with low IL1β. IL1β promoted tumor growth and increased the cancer stem cell phenotype in murine and human Proneural glioma stem cells (GSCs). IL1β activated the p38 MAPK signaling pathway and expression of monocyte chemoattractant protein (MCP-1/CCL2) by tumor cells. Loss of Cx3cr1 in microglia in a monocyte-free environment had no impact on tumor growth and did not alter microglial migration. These data suggest that enhancing signaling to CX3CR1 or inhibiting IL1β signaling in intra-tumoral macrophages can be considered as potential strategies to decrease the tumor-promoting effects of monocytes in Proneural GBM. PMID:25987130

cGAS Senses Human Cytomegalovirus and Induces Type I Interferon Responses in Human Monocyte-Derived Cells

PubMed Central

Paijo, Jennifer; Döring, Marius; Spanier, Julia; Grabski, Elena; Nooruzzaman, Mohammed; Schmidt, Tobias; Witte, Gregor; Messerle, Martin; Hornung, Veit; Kaever, Volkhard; Kalinke, Ulrich

2016-01-01

Human cytomegalovirus (HCMV) infections of healthy individuals are mostly unnoticed and result in viral latency. However, HCMV can also cause devastating disease, e.g., upon reactivation in immunocompromised patients. Yet, little is known about human immune cell sensing of DNA-encoded HCMV. Recent studies indicated that during viral infection the cyclic GMP/AMP synthase (cGAS) senses cytosolic DNA and catalyzes formation of the cyclic di-nucleotide cGAMP, which triggers stimulator of interferon genes (STING) and thus induces antiviral type I interferon (IFN-I) responses. We found that plasmacytoid dendritic cells (pDC) as well as monocyte-derived DC and macrophages constitutively expressed cGAS and STING. HCMV infection further induced cGAS, whereas STING expression was only moderately affected. Although pDC expressed particularly high levels of cGAS, and the cGAS/STING axis was functional down-stream of STING, as indicated by IFN-I induction upon synthetic cGAMP treatment, pDC were not susceptible to HCMV infection and mounted IFN-I responses in a TLR9-dependent manner. Conversely, HCMV infected monocyte-derived cells synthesized abundant cGAMP levels that preceded IFN-I production and that correlated with the extent of infection. CRISPR/Cas9- or siRNA-mediated cGAS ablation in monocytic THP-1 cells and primary monocyte-derived cells, respectively, impeded induction of IFN-I responses following HCMV infection. Thus, cGAS is a key sensor of HCMV for IFN-I induction in primary human monocyte-derived DC and macrophages. PMID:27058035

Use of Microsphere Technology for Targeted Delivery of Rifampin to Mycobacterium tuberculosis-Infected Macrophages

PubMed Central

Barrow, Esther L. W.; Winchester, Gary A.; Staas, Jay K.; Quenelle, Debra C.; Barrow, William W.

1998-01-01

Microsphere technology was used to develop formulations of rifampin for targeted delivery to host macrophages. These formulations were prepared by using biocompatible polymeric excipients of lactide and glycolide copolymers. Release characteristics were examined in vitro and also in two monocytic cell lines, the murine J774 and the human Mono Mac 6 cell lines. Bioassay assessment of cell culture supernatants from monocyte cell lines showed release of bioactive rifampin during a 7-day experimental period. Treatment of Mycobacterium tuberculosis H37Rv-infected monocyte cell lines with rifampin-loaded microspheres resulted in a significant decrease in numbers of CFU at 7 days following initial infection, even though only 8% of the microsphere-loaded rifampin was released. The levels of rifampin released from microsphere formulations within monocytes were more effective at reducing M. tuberculosis intracellular growth than equivalent doses of rifampin given as a free drug. These results demonstrate that rifampin-loaded microspheres can be formulated for effective sustained and targeted delivery to host macrophages. PMID:9756777

Apolipoprotein CIII-induced THP-1 cell adhesion to endothelial cells involves pertussis toxin-sensitive G protein- and protein kinase C alpha-mediated nuclear factor-kappaB activation.

PubMed

Kawakami, Akio; Aikawa, Masanori; Nitta, Noriko; Yoshida, Masayuki; Libby, Peter; Sacks, Frank M

2007-01-01

Plasma apolipoprotein CIII (apoCIII) independently predicts risk for coronary heart disease (CHD). We recently reported that apoCIII directly enhances adhesion of human monocytes to endothelial cells (ECs), and identified the activation of PKC alpha as a necessary upstream event of enhanced monocyte adhesion. This study tested the hypothesis that apoCIII activates PKC alpha in human monocytic THP-1 cells, leading to NF-kappaB activation. Among inhibitors specific to PKC activators, phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor D609 limited apoCIII-induced PKC alpha activation and THP-1 cell adhesion. ApoCIII increased PC-PLC activity in THP-1 cells, resulting in PKC alpha activation. Pertussis toxin (PTX) inhibited apoCIII-induced PC-PLC activation and subsequent PKC alpha activation, implicating PTX-sensitive G protein pathway. ApoCIII further activated nuclear factor-kappaB (NF-kappaB) through PKC alpha in THP-1 cells and augmented beta1-integrin expression. The NF-kappaB inhibitor peptide SN50 partially inhibited apoCIII-induced beta1-integrin expression and THP-1 cell adhesion. ApoCIII-rich VLDL had similar effects to apoCIII alone. PTX-sensitive G protein pathway participates critically in PKC alpha stimulation in THP-1 cells exposed to apoCIII, activating NF-kappaB, and increasing beta1-integrin. This action causes monocytic cells to adhere to endothelial cells. Furthermore, because leukocyte NF-kappaB activation contributes to inflammatory aspects of atherogenesis, apoCIII may stimulate diverse inflammatory responses through monocyte activation.

Differential regulation of cell functions by CSD peptide subdomains

PubMed Central

2013-01-01

Background In fibrotic lung diseases, expression of caveolin-1 is decreased in fibroblasts and monocytes. The effects of this deficiency are reversed by treating cells or animals with the caveolin-1 scaffolding domain peptide (CSD, amino acids 82–101 of caveolin-1) which compensates for the lack of caveolin-1. Here we compare the function of CSD subdomains (Cav-A, Cav-B, Cav-C, Cav-AB, and Cav-BC) and mutated versions of CSD (F92A and T90A/T91A/F92A). Methods Migration toward the chemokine CXCL12 and the associated expression of F-actin, CXCR4, and pSmad 2/3 were studied in monocytes from healthy donors and SSc patients. Fibrocyte differentiation was studied using PBMC from healthy donors and SSc patients. Collagen I secretion and signaling were studied in fibroblasts derived from the lung tissue of healthy subjects and SSc patients. Results Cav-BC and CSD at concentrations as low as 0.01 μM inhibited the hypermigration of SSc monocytes and TGFβ-activated Normal monocytes and the differentiation into fibrocytes of SSc and Normal monocytes. While CSD also inhibited the migration of poorly migrating Normal monocytes, Cav-A (and other subdomains to a lesser extent) promoted the migration of Normal monocytes while inhibiting the hypermigration of TGFβ-activated Normal monocytes. The effects of versions of CSD on migration may be mediated in part via their effects on CXCR4, F-actin, and pSmad 2/3 expression. Cav-BC was as effective as CSD in inhibiting fibroblast collagen I and ASMA expression and MEK/ERK signaling. Cav-C and Cav-AB also inhibited collagen I expression, but in many cases did not affect ASMA or MEK/ERK. Cav-A increased collagen I expression in scleroderma lung fibroblasts. Full effects on fibroblasts of versions of CSD required 5 μM peptide. Conclusions Cav-BC retains most of the anti-fibrotic functions of CSD; Cav-A exhibits certain pro-fibrotic functions. Results obtained with subdomains and mutated versions of CSD further suggest that the critical functional residues in CSD depend on the cell type and readout being studied. Monocytes may be more sensitive to versions of CSD than fibroblasts and endothelial cells because the baseline level of caveolin-1 in monocytes is much lower than in these other cell types. PMID:24011378

Differential regulation of cell functions by CSD peptide subdomains.

PubMed

Reese, Charles; Dyer, Shanice; Perry, Beth; Bonner, Michael; Oates, James; Hofbauer, Ann; Sessa, William; Bernatchez, Pascal; Visconti, Richard P; Zhang, Jing; Hatfield, Corey M; Silver, Richard M; Hoffman, Stanley; Tourkina, Elena

2013-09-08

In fibrotic lung diseases, expression of caveolin-1 is decreased in fibroblasts and monocytes. The effects of this deficiency are reversed by treating cells or animals with the caveolin-1 scaffolding domain peptide (CSD, amino acids 82-101 of caveolin-1) which compensates for the lack of caveolin-1. Here we compare the function of CSD subdomains (Cav-A, Cav-B, Cav-C, Cav-AB, and Cav-BC) and mutated versions of CSD (F92A and T90A/T91A/F92A). Migration toward the chemokine CXCL12 and the associated expression of F-actin, CXCR4, and pSmad 2/3 were studied in monocytes from healthy donors and SSc patients. Fibrocyte differentiation was studied using PBMC from healthy donors and SSc patients. Collagen I secretion and signaling were studied in fibroblasts derived from the lung tissue of healthy subjects and SSc patients. Cav-BC and CSD at concentrations as low as 0.01 μM inhibited the hypermigration of SSc monocytes and TGFβ-activated Normal monocytes and the differentiation into fibrocytes of SSc and Normal monocytes. While CSD also inhibited the migration of poorly migrating Normal monocytes, Cav-A (and other subdomains to a lesser extent) promoted the migration of Normal monocytes while inhibiting the hypermigration of TGFβ-activated Normal monocytes. The effects of versions of CSD on migration may be mediated in part via their effects on CXCR4, F-actin, and pSmad 2/3 expression. Cav-BC was as effective as CSD in inhibiting fibroblast collagen I and ASMA expression and MEK/ERK signaling. Cav-C and Cav-AB also inhibited collagen I expression, but in many cases did not affect ASMA or MEK/ERK. Cav-A increased collagen I expression in scleroderma lung fibroblasts. Full effects on fibroblasts of versions of CSD required 5 μM peptide. Cav-BC retains most of the anti-fibrotic functions of CSD; Cav-A exhibits certain pro-fibrotic functions. Results obtained with subdomains and mutated versions of CSD further suggest that the critical functional residues in CSD depend on the cell type and readout being studied. Monocytes may be more sensitive to versions of CSD than fibroblasts and endothelial cells because the baseline level of caveolin-1 in monocytes is much lower than in these other cell types.

Human Monocytes Accelerate Proliferation and Blunt Differentiation of Preadipocytes in Association With Suppression of C/Ebpα mRNA

PubMed Central

Couturier, Jacob; Patel, Sanjeet G.; Iyer, Dinakar; Balasubramanyam, Ashok; Lewis, Dorothy E.

2015-01-01

Obesity, type 2 diabetes, and HIV-associated lipodystrophy are associated with abnormalities in adipocyte growth and differentiation. In persons with these conditions, adipose depots contain increased numbers of macrophages, but the origins of these cells and their specific effects are uncertain. Peripheral blood mononuclear cells (PBMC)-derived monocytes, but not T cells, cocultured via transwells with primary subcutaneous preadipocytes, increased proliferation (approximately twofold) and reduced differentiation (~50%) of preadipocytes. Gene expression analyses in proliferating preadipocytes (i.e., prior to hormonal induction of terminal differentiation) revealed that monocytes down-regulated mRNA levels of CCAAT/enhancer binding protein, alpha (C/EBPα) and up-regulated mRNA levels of G0/G1 switch 2 (G0S2) message, genes important for the regulation of adipogenesis and the cell cycle. These data indicate that circulating peripheral blood monocytes can disrupt adipogenesis by interfering with a critical step in C/EBPα and G0S2 transcription required for preadipocytes to make the transition from proliferation to differentiation. Interactions between preadipocytes and monocytes also increased the inflammatory cytokines IL-6 and IL-8, as well as a novel chemotactic cytokine, CXCL1. Additionally, the levels of both IL-6 and CXCL1 were highest when preadipocytes and monocytes were cultured together, compared to each cell in culture alone. Such cross-talk amplifies the production of mediators of tissue inflammation. PMID:21869759

Outside-in HLA class I signaling regulates ICAM-1 clustering and endothelial cell-monocyte interactions via mTOR in transplant antibody-mediated rejection.

PubMed

Salehi, Sahar; Sosa, Rebecca A; Jin, Yi-Ping; Kageyama, Shoichi; Fishbein, Michael C; Rozengurt, Enrique; Kupiec-Weglinski, Jerzy W; Reed, Elaine F

2018-05-01

Antibody-mediated rejection (AMR) resulting in transplant allograft vasculopathy (TAV) is the major obstacle for long-term survival of solid organ transplants. AMR is caused by donor-specific antibodies to HLA, which contribute to TAV by initiating outside-in signaling transduction pathways that elicit monocyte recruitment to activated endothelium. Mechanistic target of rapamycin (mTOR) inhibitors can attenuate TAV; therefore, we sought to understand the mechanistic underpinnings of mTOR signaling in HLA class I Ab-mediated endothelial cell activation and monocyte recruitment. We used an in vitro model to assess monocyte binding to HLA I Ab-activated endothelial cells and found mTOR inhibition reduced ezrin/radixin/moesin (ERM) phosphorylation, intercellular adhesion molecule 1 (ICAM-1) clustering, and monocyte firm adhesion to HLA I Ab-activated endothelium. Further, in a mouse model of AMR, in which C57BL/6. RAG1 -/- recipients of BALB/c cardiac allografts were passively transferred with donor-specific MHC I antibodies, mTOR inhibition significantly reduced vascular injury, ERM phosphorylation, and macrophage infiltration of the allograft. Taken together, these studies indicate mTOR inhibition suppresses ERM phosphorylation in endothelial cells, which impedes ICAM-1 clustering in response to HLA class I Ab and prevents macrophage infiltration into cardiac allografts. These findings indicate a novel therapeutic application for mTOR inhibitors to disrupt endothelial cell-monocyte interactions during AMR. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Interaction of PRRS virus with bone marrow monocyte subsets.

PubMed

Fernández-Caballero, Teresa; Álvarez, Belén; Alonso, Fernando; Revilla, Concepción; Martínez-Lobo, Javier; Prieto, Cinta; Ezquerra, Ángel; Domínguez, Javier

2018-06-01

PRRSV can replicate for months in lymphoid organs leading to persistent host infections. Porcine bone marrow comprises two major monocyte subsets, one of which expresses CD163 and CD169, two receptors involved in the entry of PRRSV in macrophages. In this study, we investigate the permissiveness of these subsets to PRRSV infection. PRRSV replicates efficiently in BM CD163 + monocytes reaching titers similar to those obtained in alveolar macrophages, but with a delayed kinetics. Infection of BM CD163 - monocytes was variable and yielded lower titers. This may be related with the capacity of BM CD163 - monocytes to differentiate into CD163 + CD169 + cells after culture in presence of M-CSF. Both subsets secreted IL-8 in response to virus but CD163 + cells tended to produce higher amounts. The infection of BM monocytes by PRRSV may contribute to persistence of the virus in this compartment and to hematological disorders found in infected animals such as the reduction in the number of peripheral blood monocytes. Copyright © 2018 Elsevier B.V. All rights reserved.

Membrane Type 1 Matrix Metalloproteinase Regulates Monocyte Migration and Collagen Destruction in Tuberculosis.

PubMed

Sathyamoorthy, Tarangini; Tezera, Liku B; Walker, Naomi F; Brilha, Sara; Saraiva, Luisa; Mauri, Francesco A; Wilkinson, Robert J; Friedland, Jon S; Elkington, Paul T

2015-08-01

Tuberculosis (TB) remains a global pandemic and drug resistance is rising. Multicellular granuloma formation is the pathological hallmark of Mycobacterium tuberculosis infection. The membrane type 1 matrix metalloproteinase (MT1-MMP or MMP-14) is a collagenase that is key in leukocyte migration and collagen destruction. In patients with TB, induced sputum MT1-MMP mRNA levels were increased 5.1-fold compared with matched controls and correlated positively with extent of lung infiltration on chest radiographs (r = 0.483; p < 0.05). M. tuberculosis infection of primary human monocytes increased MT1-MMP surface expression 31.7-fold and gene expression 24.5-fold. M. tuberculosis-infected monocytes degraded collagen matrix in an MT1-MMP-dependent manner, and MT1-MMP neutralization decreased collagen degradation by 73%. In human TB granulomas, MT1-MMP immunoreactivity was observed in macrophages throughout the granuloma. Monocyte-monocyte networks caused a 17.5-fold increase in MT1-MMP surface expression dependent on p38 MAPK and G protein-coupled receptor-dependent signaling. Monocytes migrating toward agarose beads impregnated with conditioned media from M. tuberculosis-infected monocytes expressed MT1-MMP. Neutralization of MT1-MMP activity decreased this M. tuberculosis network-dependent monocyte migration by 44%. Taken together, we demonstrate that MT1-MMP is central to two key elements of TB pathogenesis, causing collagen degradation and regulating monocyte migration. Copyright © 2015 The Authors.

Functional Defects in Type 3 Innate Lymphoid Cells and Classical Monocytes in a Patient with Hyper-IgE Syndrome.

PubMed

Chang, Yuna; Kang, Sung-Yoon; Kim, Jihyun; Kang, Hye-Ryun; Kim, Hye Young

2017-10-01

Hyper-IgE syndrome (HIES) is a very rare primary immune deficiency characterized by elevated serum IgE levels, recurrent bacterial infections, chronic dermatitis, and connective tissue abnormalities. Autosomal dominant (AD) HIES involves a mutation in signal transducer and activator of transcription 3 (STAT3) that leads to an impaired T H 17 response. STAT3 signaling is also involved in the function of RORγt + type 3 innate lymphoid cells (ILC3s) and RORγt + T H 17 cells. The aim of this study was to investigate the role of innate immune cells such as innate lymphoid cells (ILCs), granulocytes, and monocytes in a patient with HIES. Peripheral blood mononuclear cells (PBMCs) from a patient with HIES and three age-matched healthy controls were obtained for the analysis of the innate and adaptive immune cells. The frequencies of ILCs in PBMCs were lower in the patient with HIES than in the controls. Moreover, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-17A produced by ILC3s in PBMCs were lower in the patient with HIES than the controls. Compared with the controls, classical monocytes (CD14 + CD16 low ), which have a high antimicrobial capability, were also lower in the patient with HIES, while non-classical monocytes (CD14 low CD16 + ) as well as intermediate monocytes (CD14 + CD16 intermediate ) were higher. Taken together, these results indicate that the impaired immune defense against pathogenic microbes in the patient with HIES might be partially explained by functional defects in ILC3s and inflammatory monocytes.

PSGL-1 is highly expressed on Ly-6Chi monocytes and a major determinant for Ly-6Chi monocyte recruitment to sites of atherosclerosis in mice

PubMed Central

An, Guangyu; Wang, Huan; Tang, Rong; Yago, Tadayuki; McDaniel, J. Michael; McGee, Samuel; Huo, Yuqing; Xia, Lijun

2008-01-01

Background Ly-6Chi monocytes are key contributors to atherosclerosis in mice. However, how Ly-6Chi monocytes selectively accumulate in atherosclerotic lesions is largely unknown. Monocyte homing to sites of atherosclerosis is primarily initiated by rolling on P- and E-selectin expressed on endothelium. We hypothesize that P-selectin glycoprotein ligand-1 (PSGL-1), the common ligand of P- and E-selectin on leukocytes, contributes to the preferential homing of Ly-6Chi monocytes to atherosclerotic lesions. Methods and Results To test this hypothesis, we examined the expression and function of PSGL-1 on Ly-6Chi and Ly-6Clo monocytes from wild-type mice, ApoE-/- mice, and mice lacking both ApoE and PSGL-1 genes (ApoE-/-/PSGL-1-/-). We found that Ly-6Chi monocytes expressed a higher level of PSGL-1, and had enhanced binding to fluid-phase P- and E-selectin, compared to Ly-6Clo monocytes. Under in vitro flow conditions, more Ly-6Chi monocytes rolled on P-, E-, and L-selectin at slower velocities than Ly-6Clo cells. In an ex vivo perfused carotid artery model, Ly-6Chi monocytes interacted preferentially with atherosclerotic endothelium compared with Ly-6Clo monocytes in a PSGL-1-dependent manner. In vivo, ApoE-/- mice lacking PSGL-1 had impaired Ly-6Chi monocyte recruitment to atherosclerotic lesions. Moreover, ApoE-/-/PSGL-1-/- mice exhibited significantly reduced monocyte infiltration in wire injury-induced neointima and in atherosclerotic lesions. ApoE-/-/PSGL-1-/- mice also developed smaller neointima and atherosclerotic plaques. Conclusions These data indicate that PSGL-1 is a new marker for Ly-6Chi monocytes and a major determinant for Ly-6Chi cell recruitment to sites of atherosclerosis in mice. PMID:18519846

Supernatants from oral epithelial cells and gingival fibroblasts modulate human immunodeficiency virus type 1 promoter activation induced by periodontopathogens in monocytes/macrophages.

PubMed

González, O A; Ebersole, J L; Huang, C B

2010-04-01

Bacterial and host cell products during coinfections of Human Immunodeficiency Virus type 1-positive (HIV-1(+)) patients regulate HIV-1 recrudescence in latently infected cells (e.g. T cells, monocytes/macrophages), impacting highly active antiretroviral therapy (HAART) failure and progression of acquired immunodeficiency syndrome. A high frequency of oral opportunistic infections (e.g. periodontitis) in HIV-1(+) patients has been demonstrated; however, their potential to impact HIV-1 exacerbation is unclear. We sought to determine the ability of supernatants derived from oral epithelial cells (OKF4) and human gingival fibroblasts (Gin-4) challenged with periodontal pathogens, to modulate the HIV-1 promoter activation in monocytes/macrophages. BF24 monocytes/macrophages transfected with the HIV-1 promoter driving the expression of chloramphenicol acetyltransferase (CAT) were stimulated with Porphyromonas gingivalis, Fusobacterium nucleatum, or Treponema denticola in the presence of supernatants from OKF4 or Gin4 cells either unstimulated or previously pulsed with bacteria. CAT levels were determined by enzyme-linked immunosorbent assay and cytokine production was evaluated by Luminex beadlyte assays. OKF4 and Gin4 supernatants enhanced HIV-1 promoter activation particularly related to F. nucleatum challenge. An additive effect was observed in HIV-1 promoter activation when monocytes/macrophages were simultaneously stimulated with gingival cell supernatants and bacterial extracts. OKF4 cells produced higher levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukins -6 and -8 in response to F. nucleatum and P. gingivalis. Preincubation of OKF4 supernatants with anti-GM-CSF reduced the additive effect in periodontopathogen-induced HIV-1 promoter activation. These results suggest that soluble mediators produced by gingival resident cells in response to periodontopathogens could contribute to HIV-1 promoter activation in monocytes/macrophages, albeit this effect is most notable following direct stimulation of the cells with oral gram-negative bacteria.

Dysregulated Functions of Lung Macrophage Populations in COPD.

PubMed

Kapellos, Theodore S; Bassler, Kevin; Aschenbrenner, Anna C; Fujii, Wataru; Schultze, Joachim L

2018-01-01

Chronic obstructive pulmonary disease (COPD) is a diverse respiratory disease characterised by bronchiolitis, small airway obstruction, and emphysema. Innate immune cells play a pivotal role in the disease's progression, and in particular, lung macrophages exploit their prevalence and strategic localisation to orchestrate immune responses. To date, alveolar and interstitial resident macrophages as well as blood monocytes have been described in the lungs of patients with COPD contributing to disease pathology by changes in their functional repertoire. In this review, we summarise recent evidence from human studies and work with animal models of COPD with regard to altered functions of each of these myeloid cell populations. We primarily focus on the dysregulated capacity of alveolar macrophages to secrete proinflammatory mediators and proteases, induce oxidative stress, engulf microbes and apoptotic cells, and express surface and intracellular markers in patients with COPD. In addition, we discuss the differences in the responses between alveolar macrophages and interstitial macrophages/monocytes in the disease and propose how the field should advance to better understand the implications of lung macrophage functions in COPD.

Dysregulated Functions of Lung Macrophage Populations in COPD

PubMed Central

Bassler, Kevin; Aschenbrenner, Anna C.

2018-01-01

Chronic obstructive pulmonary disease (COPD) is a diverse respiratory disease characterised by bronchiolitis, small airway obstruction, and emphysema. Innate immune cells play a pivotal role in the disease's progression, and in particular, lung macrophages exploit their prevalence and strategic localisation to orchestrate immune responses. To date, alveolar and interstitial resident macrophages as well as blood monocytes have been described in the lungs of patients with COPD contributing to disease pathology by changes in their functional repertoire. In this review, we summarise recent evidence from human studies and work with animal models of COPD with regard to altered functions of each of these myeloid cell populations. We primarily focus on the dysregulated capacity of alveolar macrophages to secrete proinflammatory mediators and proteases, induce oxidative stress, engulf microbes and apoptotic cells, and express surface and intracellular markers in patients with COPD. In addition, we discuss the differences in the responses between alveolar macrophages and interstitial macrophages/monocytes in the disease and propose how the field should advance to better understand the implications of lung macrophage functions in COPD. PMID:29670919

Interaction between Salmonella typhimurium and phagocytic cells in pigs. Phagocytosis, oxidative burst and killing in polymorphonuclear leukocytes and monocytes.

PubMed

Riber, U; Lind, P

1999-02-22

Interactions between Salmonella typhimurium and peripheral blood leucocytes from healthy, Salmonella-free pigs were investigated in vitro. Both granulocytes and monocytes phagocytized FITC-labelled heat-killed Salmonella bacteria as shown by flow cytometry. Phagocytosis in whole blood and isolated leucocytes was measured as acquired fluorescence in the leukocytes and was both time and dose related. Living, serum-opsonized Salmonella bacteria induced a dose-dependent oxidative burst in PMNs and monocytes as measured by luminol-enhanced chemiluminescence (LC). When opsonized in normal serum the Salmonella bacteria, in the range of 2-5 x 10(7) cfu, induced a LC response in monocytes comparable to the level of responses induced by phorbol myristate acetate (PMA) and opsonized zymosan, and the Salmonella-induced response was only marginally reduced by superoxide dismutase (SOD). Intracellular killing of Salmonella by monocytes was assessed from plate colony counts of lysed monocytes and showed that Salmonella typhimurium was able to survive and proliferate in adherent monocytes in vitro despite a reduction in intracellular cfu during the first hour's incubation in cells from some pigs. Experiments with the exhaustion of oxidative burst in non-adherent monocytes were performed by prestimulation with PMA, heat-killed Salmonella or buffer. Prestimulation with PMA led to a strong reduction in oxidative burst induced by living opsonized Salmonella bacteria, whereas prestimulation with heat-killed bacteria gave rise to an enhanced response. In these experiments intracellular killing of the added living Salmonella gave variable results, in that monocytes from two out of three pigs showed no essential change in intracellular bactericidal activity, but with cells from one pig a less pronounced bactericidal activity was found after prestimulation with PMA.

Targeting of colony-stimulating factor 1 receptor (CSF1R) in the CLL microenvironment yields antineoplastic activity in primary patient samples.

PubMed

Edwards V, David K; Sweeney, David Tyler; Ho, Hibery; Eide, Christopher A; Rofelty, Angela; Agarwal, Anupriya; Liu, Selina Qiuying; Danilov, Alexey V; Lee, Patrice; Chantry, David; McWeeney, Shannon K; Druker, Brian J; Tyner, Jeffrey W; Spurgeon, Stephen E; Loriaux, Marc M

2018-05-15

In many malignancies, the tumor microenvironment includes CSF1R-expressing supportive monocyte/macrophages that promote tumor cell survival. For chronic lymphocytic leukemia (CLL), these supportive monocyte/macrophages are known as nurse-like cells (NLCs), although the potential effectiveness of selective small-molecule inhibitors of CSF1R against CLL is understudied. Here, we demonstrate the preclinical activity of two inhibitors of CSF1R, GW-2580 and ARRY-382, in primary CLL patient samples. We observed at least 25% of CLL samples showed sub-micromolar sensitivity to CSF1R inhibitors. This sensitivity was observed in samples with varying genetic and clinical backgrounds, although higher white cell count and monocyte cell percentage was associated with increased sensitivity. Depleting CD14-expressing monocytes preferentially decreased viability in samples sensitive to CSF1R inhibitors, and treating samples with CSF1R inhibitors eliminated the presence of NLCs in long-term culture conditions. These results indicate that CSF1R small-molecule inhibitors target CD14-expressing monocytes in the CLL microenvironment, thereby depriving leukemia cells of extrinsic support signals. In addition, significant synergy was observed combining CSF1R inhibitors with idelalisib or ibrutinib, two current CLL therapies that disrupt tumor cell intrinsic B-cell receptor signaling. These findings support the concept of simultaneously targeting supportive NLCs and CLL cells and demonstrate the potential clinical utility of this combination.

GST-M1 is transcribed moreso than AKR7A2 in AFB₁-exposed human monocytes and lymphocytes.

PubMed

Bahari, Abbas; Mehrzad, Jalil; Mahmoudi, Mahmoud; Bassami, Mohammad Reza; Dehghani, Hesam

2015-01-01

Glutathione-S-transferases (GST) and aldo-keto reductases (AKR) are key aflatoxin (AF)-detoxifying enzymes. In this study, the expression of GST-M1, GST-T1, AKR-7A2, and AKR-7A3 genes in human monocytes and lymphocytes was analyzed after in vitro exposure to 10 or 100 ng AFB1/ml for 2 h. Unlike in pilot studies that showed that all four examined genes were present in HepG2 cells, in lymphocytes and monocytes, only GST-M1 and AKR-7A2 were detected. In fact, the induced expression of both GST-M1 and AKR-7A2 genes in human monocytes was moreso than that seen in AFB1-exposed lymphocytes. In addition, analyses of the effects of the exposures on cell cycle status were performed as, in cells lacking adequate detoxification capacities, it would be expected the cells would arrest at checkpoints in the cell cycle or progress to apoptotic/necrotic states. The results here indicated that only the high dose of AFB1 led to a change in cell cycle profiles and only in the monocytes (i.e. cells in S phase were significantly reduced). In general, the results here strongly suggest that human immune cell lineages appear to be able to increase their expression of AFB1-detoxifying enzymes (albeit to differing degrees) and, as a result, are able to counter potential toxicities from AFB1 and (likely) its metabolites.

Niacin results in reduced monocyte adhesion in patients with type 2 diabetes mellitus.

PubMed

Tavintharan, S; Woon, K; Pek, L T; Jauhar, N; Dong, X; Lim, S C; Sum, C F

2011-03-01

Patients with type 2 diabetes have increased expression of cell adhesion molecules (CAMs). CAMs and monocyte adhesion mediate essential processes in atherogenesis. It remains unclear if monocytes from patients on niacin have reduced adhesion function. We studied the variation of monocyte adhesion in patients with type 2 diabetes and low HDL-cholesterol, taking either extended release niacin (Niaspan®, Abbott Laboratories) or controls not on niacin. Biochemical parameters including adiponectin, CAMs and fresh monocytes from whole blood for adhesion assays, were studied at baseline and 12-weeks. Niacin 1500 mg daily raised HDL-cholesterol from 0.8 mmol/l (95% CI: 0.7-0.9) to 0.9 mmol/l (95% CI: 0.8-1.1), p=0.10, and significantly reduced PECAM-1 by 24.9% (95% CI: 10.9-39.0; p<0.05), increased adiponectin by 30.5% (95% CI: 14.1-47.0; p<0.05), with monocyte adhesion reduced by 9.2% (95%CI: 0.7-17.7; p<0.05) in endothelial cells treated in basal conditions, and 7.8% (95% CI: 3.1-12.5; p<0.05) after TNF-α stimulation. Monocytes isolated from patients on niacin had reduced adhesion to endothelial cells. Our findings suggest niacin has broad range of effects apart from lipid-modification, and these could be important in cardiovascular risk reduction. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Monocyte Activation in Immunopathology: Cellular Test for Development of Diagnostics and Therapy.

PubMed

Ivanova, Ekaterina A; Orekhov, Alexander N

2016-01-01

Several highly prevalent human diseases are associated with immunopathology. Alterations in the immune system are found in such life-threatening disorders as cancer and atherosclerosis. Monocyte activation followed by macrophage polarization is an important step in normal immune response to pathogens and other relevant stimuli. Depending on the nature of the activation signal, macrophages can acquire pro- or anti-inflammatory phenotypes that are characterized by the expression of distinct patterns of secreted cytokines and surface antigens. This process is disturbed in immunopathologies resulting in abnormal monocyte activation and/or bias of macrophage polarization towards one or the other phenotype. Such alterations could be used as important diagnostic markers and also as possible targets for the development of immunomodulating therapy. Recently developed cellular tests are designed to analyze the phenotype and activity of living cells circulating in patient's bloodstream. Monocyte/macrophage activation test is a successful example of cellular test relevant for atherosclerosis and oncopathology. This test demonstrated changes in macrophage activation in subclinical atherosclerosis and breast cancer and could also be used for screening a panel of natural agents with immunomodulatory activity. Further development of cellular tests will allow broadening the scope of their clinical implication. Such tests may become useful tools for drug research and therapy optimization.

The role and mechanism of KCa3.1 channels in human monocyte migration induced by palmitic acid.

PubMed

Ma, Xiao-Zhen; Pang, Zheng-Da; Wang, Jun-Hong; Song, Zheng; Zhao, Li-Mei; Du, Xiao-Jun; Deng, Xiu-Ling

2018-05-21

Monocyte migration into diseased tissues contributes to the pathogenesis of diseases. Intermediate-conductance Ca 2+ -activated K + (K Ca 3.1) channels play an important role in cell migration. However, the role of K Ca 3.1 channels in mediating monocyte migration induced by palmitic acid (PA) is still unclear. Using cultured THP-1 cells and peripheral blood mononuclear cells from healthy subjects, we investigated the role and signaling mechanisms of K Ca 3.1 channels in mediating the migration induced by PA. Using methods of Western blotting analysis, RNA interference, cell migration assay and ELISA, we found that PA-treated monocytes exhibited increment of the protein levels of K Ca 3.1 channel and monocyte chemoattractant protein-1 (MCP-1), and the effects were reversed by co-incubation of PA with anti-TLR2/4 antibodies or by specific inhibitors of p38-MAPK, or NF-κB. In addition, PA increased monocyte migration, which was abolished by a specific K Ca 3.1 channel blocker, TRAM-34, or K Ca 3.1 small interfering RNA (siRNA). The expression and secretion of MCP-1 induced by PA was also similarly prevented by TRAM-34 and K Ca 3.1 siRNA. These results demonstrate for the first time that PA upregulates K Ca 3.1 channels through TLR2/4, p38-MAPK and NF-κB pathway to promote the expression of MCP-1, and then induce the trans-endothelial migration of monocytes. Copyright © 2018 Elsevier Inc. All rights reserved.

Repair of astrocytes, blood vessels, and myelin in the injured brain: possible roles of blood monocytes

PubMed Central

2013-01-01

Inflammation in injured tissue has both repair functions and cytotoxic consequences. However, the issue of whether brain inflammation has a repair function has received little attention. Previously, we demonstrated monocyte infiltration and death of neurons and resident microglia in LPS-injected brains (Glia. 2007. 55:1577; Glia. 2008. 56:1039). Here, we found that astrocytes, oligodendrocytes, myelin, and endothelial cells disappeared in the damage core within 1–3 d and then re-appeared at 7–14 d, providing evidence of repair of the brain microenvironment. Since round Iba-1+/CD45+ monocytes infiltrated before the repair, we examined whether these cells were involved in the repair process. Analysis of mRNA expression profiles showed significant upregulation of repair/resolution-related genes, whereas proinflammatory-related genes were barely detectable at 3 d, a time when monocytes filled injury sites. Moreover, Iba-1+/CD45+ cells highly expressed phagocytic activity markers (e.g., the mannose receptors, CD68 and LAMP2), but not proinflammatory mediators (e.g., iNOS and IL1β). In addition, the distribution of round Iba-1+/CD45+ cells was spatially and temporally correlated with astrocyte recovery. We further found that monocytes in culture attracted astrocytes by releasing soluble factor(s). Together, these results suggest that brain inflammation mediated by monocytes functions to repair the microenvironment of the injured brain. PMID:23758980

Monocyte-macrophage membrane possesses free radicals scavenging activity: stimulation by polyphenols or by paraoxonase 1 (PON1).

PubMed

Rosenblat, M; Elias, A; Volkova, N; Aviram, M

2013-04-01

In the current study, we analysed free radicals scavenging activity of monocytes-macrophages in the absence or presence of antioxidants such as polyphenols or paraoxonase 1 (PON1). THP-1 human monocytic cell line, murine J774A.1 macrophages, as well as human primary monocytes have the capability to scavenge free radicals, as measured by the 1-diphenyl-2-picryl-hydrazyl (DPPH) assay. This effect (which could be attributed to the cell's membrane) was cell number and incubation time dependent. Upon incubation of J774A.1 macrophages with acetylated LDL (Ac-LDL), with VLDL, or with the radical generator, AAPH, the cells' lipid peroxides content, and paraoxonase 2 (PON2) activity were significantly increased. While non-treated cells decreased DPPH absorbance by 65%, the Ac-LDL-, VLDL- or AAPH-treated cells, decreased it by only 33%, 30%, or 45%, respectively. We next analysed the effect of J774A.1 macrophage enrichment with antioxidants, such as polyphenols or PON1 on the cells' free radicals scavenging activity. Non-treated cells decreased DPPH absorbance by 50%, whereas vitamin E-, punicalagin- or PJ-treated cells significantly further decreased it, by 75%. Similarly, in PON1-treated cells DPPH absorbance was further decreased by 63%, in association with 23% increment in PON1 catalytic activity. In cells under oxidative stress [treated with AAPH-, or with oxidized LDL], PON1 activity was decreased by 31% or 40%, as compared to the activity observed in PON1 incubated with non-treated cells. We conclude that monocytes-macrophages possess free radicals scavenging activity, which is decreased under atherogenic conditions, and increased upon cell enrichment with potent antioxidants such as nutritional polyphenols, or PON1.

The fungal quorum-sensing molecule farnesol activates innate immune cells but suppresses cellular adaptive immunity.

PubMed

Leonhardt, Ines; Spielberg, Steffi; Weber, Michael; Albrecht-Eckardt, Daniela; Bläss, Markus; Claus, Ralf; Barz, Dagmar; Scherlach, Kirstin; Hertweck, Christian; Löffler, Jürgen; Hünniger, Kerstin; Kurzai, Oliver

2015-03-17

Farnesol, produced by the polymorphic fungus Candida albicans, is the first quorum-sensing molecule discovered in eukaryotes. Its main function is control of C. albicans filamentation, a process closely linked to pathogenesis. In this study, we analyzed the effects of farnesol on innate immune cells known to be important for fungal clearance and protective immunity. Farnesol enhanced the expression of activation markers on monocytes (CD86 and HLA-DR) and neutrophils (CD66b and CD11b) and promoted oxidative burst and the release of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α] and macrophage inflammatory protein 1 alpha [MIP-1α]). However, this activation did not result in enhanced fungal uptake or killing. Furthermore, the differentiation of monocytes to immature dendritic cells (iDC) was significantly affected by farnesol. Several markers important for maturation and antigen presentation like CD1a, CD83, CD86, and CD80 were significantly reduced in the presence of farnesol. Furthermore, farnesol modulated migrational behavior and cytokine release and impaired the ability of DC to induce T cell proliferation. Of major importance was the absence of interleukin 12 (IL-12) induction in iDC generated in the presence of farnesol. Transcriptome analyses revealed a farnesol-induced shift in effector molecule expression and a down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor during monocytes to iDC differentiation. Taken together, our data unveil the ability of farnesol to act as a virulence factor of C. albicans by influencing innate immune cells to promote inflammation and mitigating the Th1 response, which is essential for fungal clearance. Farnesol is a quorum-sensing molecule which controls morphological plasticity of the pathogenic yeast Candida albicans. As such, it is a major mediator of intraspecies communication. Here, we investigated the impact of farnesol on human innate immune cells known to be important for fungal clearance and protective immunity. We show that farnesol is able to enhance inflammation by inducing activation of neutrophils and monocytes. At the same time, farnesol impairs differentiation of monocytes into immature dendritic cells (iDC) by modulating surface phenotype, cytokine release and migrational behavior. Consequently, iDC generated in the presence of farnesol are unable to induce proper T cell responses and fail to secrete Th1 promoting interleukin 12 (IL-12). As farnesol induced down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor, desensitization to GM-CSF could potentially explain transcriptional reprofiling of iDC effector molecules. Taken together, our data show that farnesol can also mediate Candida-host communication and is able to act as a virulence factor. Copyright © 2015 Leonhardt et al.

Characterization of the porcine monocyte-derived cell lines Cdelta2- and Cdelta2+

USDA-ARS?s Scientific Manuscript database

Cell lines Cdelta2- and Cdelta2+ were developed from monocytes obtained from a 10-month-old, crossbred, female pig at the U.S. Meat Animal Research Center, Clay Center, NE. These cells have macrophage morphology, stain positively for alpha-naphthyl esterase and negatively for peroxidase. Additiona...

Phenotype and function of CD209+ bovine blood dendritic cells, monocyte-derived-dendritic cells and monocyte-derived macrophages

USDA-ARS?s Scientific Manuscript database

Phylogenic comparisons of the mononuclear phagocyte system (MPS) of humans and mice demonstrate phenotypic divergence of dendritic cell (DC) subsets that play similar roles in innate and adaptive immunity. Although differing in phenotype, DC can be classified into four groups according to ontogeny a...

[EVALUATION OF THE HUMAN SENSITIVITY TO SMALLPOX VIRUS BY THE PRIMARY CULTURES OF THE MONOCYTE-MACROPHAGES].

PubMed

Zamedyanskaya, A S; Titova, K A; Sergeev, Al A; Kabanov, A S; Bulychev, L E; Sergeev, Ar A; Galakhova, D O; Nesterov, A E; Nosareva, O V; Shishkina, L N; Taranov, O S; Omigov, V V; Agafonov, A P; Sergeev, A N

2016-01-01

Studies of the primary cultures of granulocytes, mononuclear, and monocyte-macrophage cells derived from human blood were performed using variola virus (VARV) in the doses of 0.001-0.021 PFU/cell (plaques-forming units per cell). Positive dynamics of the virus accumulation was observed only in the monocyte-macrophages with maximum values of virus concentration (5.0-5.5 Ig PFU/ml) mainly within six days after the infection. The fact of VARV replication in the monocyte-macrophages was confirmed by the data of electron microscopy. At the same time, virus vaccines when tested in doses 3.3 and 4.2 Ig PFU/ml did not show the ability to reproduce in these human cells. The people sensitivity to VARV as assessed from the data obtained on human monocyte-macrophages corresponded to -1 PFU (taking into account the smooth interaction of the virus in the body to the cells of this type), which is consistent to previously found theoretical data on the virus sensitivity. The human susceptibility to VARV assessed experimentally can be used to predict the adequacy of developed smallpox models (in vivo) based on susceptible animals. This is necessary for reliable assessment of the efficiency of development of drugs for treatment and prophylaxis of the smallpox.

Amino acids exhibit anti-inflammatory effects in human monocytic leukemia cell line, THP-1 cells.

PubMed

Hasegawa, Shunji; Ichiyama, Takashi; Sonaka, Ichiro; Ohsaki, Ayami; Hirano, Reiji; Haneda, Yasuhiro; Fukano, Reiji; Hara, Masami; Furukawa, Susumu

2011-11-01

The elemental diet is one of the effective therapies for inflammatory bowel disease. However, the mechanism remains unclear, and there have never been reports about the inhibitory effects of amino acids in human monocytes/macrophages. We investigated the inhibitory effects of amino acids on cytokine production or expression of adhesion molecules that are involved in inflammatory diseases, in human monocytes/macrophages. We examined the inhibitory effects of cysteine, histidine or glycine on the induction of nuclear factor-κB (NF-κB) activation, expression of intracellular adhesion molecule-1 (ICAM-1, CD54) and production of interleukin-8 (IL-8) in THP-1 cells, a human monocytic leukemia cell line, and peripheral blood mononuclear cells (PBMCs) stimulated with tumor necrosis factor-α (TNF-α). Cysteine, histidine and glycine significantly reduced the activation of NF-κB in THP-1 cells stimulated with TNF-α. In addition, cysteine and histidine significantly inhibited the expression of ICAM-1 and production of IL-8 in THP-1 cells and PBMCs. Our results suggest that cysteine and histidine exhibit anti-inflammatory effects in THP-1 cells, and may be responsible for the efficacy of treatment in inflammatory bowel diseases.

Humoral and Innate Antiviral Immunity as Tools to Clear Persistent HIV Infection.

PubMed

Ferrari, Guido; Pollara, Justin; Tomaras, Georgia D; Haynes, Barton F

2017-03-15

Human immunodeficiency virus (HIV) type 1 uses the CD4 molecule as its principal receptor to infect T cells. HIV-1 integrates its viral genome into the host cell, leading to persistent infection wherein HIV-1 can remain transcriptionally silent in latently infected CD4+ T cells. On reactivation of replication-competent provirus, HIV-1 envelope glycoproteins (Env) are expressed and accumulate on the cell surface, allowing infected cells to be detected and targeted by endogenous immune responses or immune interventions. HIV-1 Env-specific antibodies have the potential to bind HIV-1 cell surface Env and promote elimination of infected CD4+ T cells by recruiting cytotoxic effector cells, such as natural killer cells, monocytes, and polymorphonuclear cells. Harnessing humoral and innate cellular responses has become one focus of research to develop innovative strategies to recruit and redirect cytotoxic effector cells to eliminate the HIV-1 latently infected CD4+ T-cell reservoir. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Endothelial monocyte activating polypeptide-II modulates endothelial cell responses by degrading hypoxia-inducible factor-1alpha through interaction with PSMA7, a component of the proteasome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tandle, Anita T.; Calvani, Maura; Uranchimeg, Badarch

The majority of human tumors are angiogenesis dependent. Understanding the specific mechanisms that contribute to angiogenesis may offer the best approach to develop therapies to inhibit angiogenesis in cancer. Endothelial monocyte activating polypeptide-II (EMAP-II) is an anti-angiogenic cytokine with potent effects on endothelial cells (ECs). It inhibits EC proliferation and cord formation, and it suppresses primary and metastatic tumor growth in-vivo. However, very little is known about the molecular mechanisms behind the anti-angiogenic activity of EMAP-II. In the present study, we explored the molecular mechanism behind the anti-angiogenic activity exerted by this protein on ECs. Our results demonstrate that EMAP-IImore » binds to the cell surface {alpha}5{beta}1 integrin receptor. The cell surface binding of EMAP-II results in its internalization into the cytoplasmic compartment where it interacts with its cytoplasmic partner PSMA7, a component of the proteasome degradation pathway. This interaction increases hypoxia-inducible factor 1-alpha (HIF-1{alpha}) degradation under hypoxic conditions. The degradation results in the inhibition of HIF-1{alpha} mediated transcriptional activity as well as HIF-1{alpha} mediated angiogenic sprouting of ECs. HIF-1{alpha} plays a critical role in angiogenesis by activating a variety of angiogenic growth factors. Our results suggest that one of the major anti-angiogenic functions of EMAP-II is exerted through its inhibition of the HIF-1{alpha} activities.« less

P-Selectin Targeted Dexamethasone-Loaded Lipid Nanoemulsions: A Novel Therapy to Reduce Vascular Inflammation

PubMed Central

Simion, Viorel; Constantinescu, Cristina Ana; Stan, Daniela; Deleanu, Mariana; Tucureanu, Monica Madalina; Butoi, Elena; Manduteanu, Ileana; Simionescu, Maya

2016-01-01

Inflammation is a common process associated with numerous vascular pathologies. We hypothesized that targeting the inflamed endothelium by coupling a peptide with high affinity for P-selectin to the surface of dexamethasone-loaded lipid nanoemulsions will highly increase their specific binding to activated endothelial cells (EC) and reduce the cell activation. We developed and characterized dexamethasone-loaded lipid nanoemulsions directed towards P-selectin (PLN-Dex) and monitored their anti-inflammatory effects in vitro using cultured EC (EA.hy926 cells) and in vivo using a mouse model of acute inflammation [lipopolysaccharides (LPS) intravenously administered in C57BL/6 mice]. We found that PLN-Dex bound specifically to the surface of activated EC are efficiently internalized by EC and reduced the expression of proinflammatory genes, thus preventing the monocyte adhesion and transmigration to/through activated EC. Given intravenously in mice with acute inflammation, PLN-Dex accumulated at a significant high level in the lungs (compared to nontargeted nanoemulsions) and significantly reduced mRNA expression level of key proinflammatory cytokines such as IL-1β, IL-6, and MCP-1. In conclusion, the newly developed nanoformulation, PLN-Dex, is functional in vitro and in vivo, reducing selectively the endothelium activation and the consequent monocyte infiltration and diminishing significantly the lungs' inflammation, in a mouse model of acute inflammation. PMID:27703301

A pathway of costimulation that prevents anergy in CD28- T cells: B7- independent costimulation of CD1-restricted T cells

PubMed Central

1995-01-01

A class of molecules that is expressed on antigen presenting cells, exemplified by CD80 (B7), has been found to provide a necessary costimulatory signal for T cell activation and proliferation. CD28 and CTLA4 are the B7 counterreceptors and are expressed on the majority of human CD4+ T cells and many CD8+ T cells. The signal these molecules mediate is distinguished from other costimulatory signals by the finding that T cell recognition of antigen results in a prolonged state of T cell unresponsiveness or anergy, unless these costimulatory molecules are engaged. However, nearly half of the CD8+ and CD4-CD8- T cells lack CD28, and the costimulatory signals required for the activation of such cells are unknown. To understand the pathways of activation used by CD28- T cells, we have examined the costimulatory requirements of antigen-specific CD4-CD8- TCR(+)-alpha/beta circulating T cells that lack the expression of CD28. We have characterized two T cell lines, DN1 and DN6, that recognize a mycobacterial antigen, and are restricted not by major histocompatibility complex class I or II, but by CD1b or CD1c, two members of a family of major histocompatibility complex-related molecules that have been recently implicated in a distinct pathway for antigen presentation. Comparison of antigen-specific cytolytic responses of the DN1 and DN6 T cell lines against antigen-pulsed CD1+ monocytes or CD1+ B lymphoblastoid cell lines (B-LCL) demonstrated that these T cells recognized antigen presented by both types of cells. However, T cell proliferation occurred only when antigen was presented by CD1+ monocytes, indicating that the CD1+ monocytes expressed a costimulatory molecule that the B- LCL transfectants lacked. This hypothesis was confirmed by demonstrating that the T cells became anergic when incubated with the CD1(+)-transfected B-LCL in the presence of antigen, but not in the absence of antigen. The required costimulatory signal occurred by a CD28-independent mechanism since both the CD1+ monocytes and CD1+ B-LCL transfectants expressed B7-1 and B7-2, and DN1 and DN6 lacked surface expression of CD28. We propose that these data define a previously unrecognized pathway of costimulation for T cells distinct from that involving CD28 and its counterreceptors. We suggest that this B7- independent pathway plays a crucial role in the activation and maintenance of tolerance of at least a subset of CD28- T cells. PMID:7500046

Comparison of two apheresis systems for the collection of CD14+ cells intended to be used in dendritic cell culture.

PubMed

Strasser, Erwin F; Berger, Thomas G; Weisbach, Volker; Zimmermann, Robert; Ringwald, Jürgen; Schuler-Thurner, Beatrice; Zingsem, Jürgen; Eckstein, Reinhold

2003-09-01

Monocytes collected by leukapheresis are increasingly used for dendritic cell (DC) culture in cell factories suitable for DC vaccination in cancer. Using modified MNC programs on two apheresis systems (Cobe Spectra and Fresenius AS.TEC204), leukapheresis components collected from 84 patients with metastatic malignant melanoma and from 31 healthy male donors were investigated. MNCs, monocytes, RBCs, and platelets (PLTs) in donors and components were analyzed by cell counters, WBC differential counts, and flow cytometry. In 5-L collections, Astec showed better results regarding monocyte collection rates (11.0 vs. 7.4 x 10(6)/min, p = 0.04) and efficiencies (collection efficiency, 51.9 vs. 31.9%; p < 0.001). Both devices resulted in monocyte yields at an average of 1 x 10(9) (donors) and 2.5 x 10(9) (patients), whereas Astec components contained high residual RBCs. Compared to components with low residual PLTs, high PLT concentration resulted in higher monocyte loss (48 vs. 20%, p < 0.0001) before DC culture. The Astec is more efficient in 5-L MNC collections compared to the Spectra. Components with high residual PLTs result in high MNC loss by purification procedures. Thus, optimizing MNC programs is essential to obtain components with high MNC yields and low residual cells as prerequisite for high DC yields.

Type I IFNs Are Required to Promote Central Nervous System Immune Surveillance through the Recruitment of Inflammatory Monocytes upon Systemic Inflammation

PubMed Central

Peralta Ramos, Javier María; Bussi, Claudio; Gaviglio, Emilia Andrea; Arroyo, Daniela Soledad; Baez, Natalia Soledad; Rodriguez-Galan, Maria Cecilia; Iribarren, Pablo

2017-01-01

Brain-resident microglia and peripheral migratory leukocytes play essential roles in shaping the immune response in the central nervous system. These cells activate and migrate in response to chemokines produced during active immune responses and may contribute to the progression of neuroinflammation. Herein, we addressed the participation of type I–II interferons in the response displayed by microglia and inflammatory monocytes to comprehend the contribution of these cytokines in the establishment and development of a neuroinflammatory process. Following systemic lipopolysaccharide (LPS) challenge, we found glial reactivity and an active recruitment of CD45hi leukocytes close to CD31+ vascular endothelial cells in circumventricular organs. Isolated CD11b+ CD45hi Ly6Chi Ly6G−-primed inflammatory monocytes were able to induce T cell proliferation, unlike CD11b+ CD45lo microglia. Moreover, ex vivo re-stimulation with LPS exhibited an enhancement of T cell proliferative response promoted by inflammatory monocytes. These myeloid cells also proved to be recruited in a type I interferon-dependent fashion as opposed to neutrophils, unveiling a role of these cytokines in their trafficking. Together, our results compares the phenotypic and functional features between tissue-resident vs peripheral recruited cells in an inflamed microenvironment, identifying inflammatory monocytes as key sentinels in a LPS-induced murine model of neuroinflammation. PMID:29255461

Flow cytometry of sputum: assessing inflammation and immune response elements in the bronchial airways

PubMed Central

Lay, John C.; Peden, David B.; Alexis, Neil E.

2012-01-01

Background The evaluation of sputum leukocytes by flow cytometry is an opportunity to assess characteristics of cells residing in the central airways, yet it is hampered by certain inherent properties of sputum including mucus and large amounts of contaminating cells and debris. Objective To develop a gating strategy based on specific antibody panels in combination with light scatter properties for flow cytometric evaluation of sputum cells. Methods Healthy and mild asthmatic volunteers underwent sputum induction. Manually selected mucus “plug” material was treated with dithiothrietol, filtered and total leukocytes acquired. Multicolor flow cytometry was performed using specific gating strategies based on light scatter properties, differential expression of CD45 and cell lineage markers to discriminate leukocytes from squamous epithelial cells and debris. Results The combination of forward scatter and CD45 expression reliably segregated sputum leukocytes from contaminating squamous epithelial cells and debris. Overlap of major leukocyte populations (neutrophils, macrophages/monocytes) required the use of specific antibodies (e.g. CD16, CD64, CD14, HLA-DR) that differentiated granulocytes from monocytes and macrophages. These gating strategies allowed identification of small populations of eosinophils, CD11c+ myeloid dendritic cells, B cells and NK cells. Conclusions Multicolor flow cytometry can be successfully applied to sputum samples to identify and characterize leukocyte populations residing on the surfaces of the central airways. PMID:21639708

Thymocyte differentiation activity from the cloned monocyte/macrophage cell line RAW 264.7. Alterations in the expression of immature thymocyte surface antigens.

PubMed

McKernan, L N; Largen, M T

1984-09-01

The cloned monocyte/macrophage cell line RAW 264.7 was previously shown to produce thymocyte mitogenic and co-mitogenic activity that eluted from a Sephadex G-75 column not only at approximately 16,000 daltons, the m.w. described for interleukin 1 (IL 1), but also at 30,000 to 40,000 daltons. The studies reported here indicate that the 30,000 to 40,000 dalton molecule has thymic differentiating activity. Thymocytes from A/J mice were fractionated on discontinuous BSA gradients, which yielded populations of cells enriched for immature and mature cells. The cells found at the interface between 35 and 29% BSA (band 1 cells), which are the most immature, were cultured for 48 hr with highly purified IL 1, with the 30,000 to 40,000 dalton form of thymocyte co-mitogenic activity obtained after Sephadex G-75 chromatography and chromatofocusing chromatography, or with media alone. The surface antigens TL-3, H-2Kk, Thy-1.2, Lyt-1, and Lyt-2 were examined by immunofluorescence. It was found that the highly purified 30,000 to 40,000 dalton species of co-mitogenic activity induced a significant increase in the content of surface H-2Kk, a decrease in TL-3, and a very small decrease in Thy-1.2 on the cell surface, whereas IL 1 was not capable of inducing a change in these surface antigens. There was no change in Lyt-1 on the surface of band 1 thymocytes after incubation with either IL 1 or the 30,000 to 40,000 dalton species. The 30,000 to 40,000 dalton species caused a significant decrease in the percentage of cells staining positive for Lyt-2, whereas IL 1 caused a smaller but significant decrease in Lyt-2. These changes in the surface markers TL-3, H-2Kk, and Thy-1.2 are consistent with changes that occur during thymocyte differentiation. It was also observed that the proliferative response to the 30,000 to 40,000 dalton form and IL 1 increased with increasing functional maturity of each band of thymocytes when used in the thymocyte mitogenic assay. However, only the 30,000 to 40,000 dalton form was capable of inducing a proliferative response in the immature band 1 thymocytes in the thymocyte co-mitogenic assay. These results indicate that the RAW 264.7 cells produce a factor that has, in addition to thymocyte co-mitogenic activity, thymocyte differentiation activity, and this factor is distinct from IL 1.

Fatty acids from VLDL lipolysis products induce lipid droplet accumulation in human monocytes

PubMed Central

den Hartigh, Laura J; Connolly-Rohrbach, Jaime E; Fore, Samantha; Huser, Thomas R; Rutledge, John C

2010-01-01

One mechanism by which monocytes become activated postprandially is by exposure to triglyceride (TG)-rich lipoproteins such as very low-density lipoproteins (VLDL). VLDL are hydrolyzed by lipoprotein lipase (LpL) at the blood-endothelial cell interface, releasing free fatty acids. In this study, we examined postprandial monocyte activation in more detail, and found that lipolysis products generated from postprandial VLDL induce the formation of lipid-filled droplets within cultured THP-1 monocytes, characterized by coherent anti-stokes Raman spectroscopy. Organelle-specific stains revealed an association of lipid droplets with the endoplasmic reticulum, confirmed by electron microscopy. Lipid droplet formation was reduced when LpL-released fatty acids were bound by bovine serum albumin, which also reduced cellular inflammation. Furthermore, saturated fatty acids induced more lipid droplet formation in monocytes compared to mono- and polyunsaturated fatty acids. Monocytes treated with postprandial VLDL lipolysis products contained lipid droplets with more intense saturated Raman spectroscopic signals than monocytes treated with fasting VLDL lipolysis products. In addition, we found that human monocytes isolated during the peak postprandial period contain more lipid droplets compared to those from the fasting state, signifying that their development is not limited to cultured cells but also occurs in vivo. In summary, circulating free fatty acids can mediate lipid droplet formation in monocytes and potentially be used as a biomarker to assess an individual’s risk of developing atherosclerotic cardiovascular disease. PMID:20208007

Recruitment of Gr-1+ monocytes is essential for control of acute toxoplasmosis

PubMed Central

Robben, Paul M.; LaRegina, Marie; Kuziel, William A.; Sibley, L. David

2005-01-01

Circulating murine monocytes comprise two largely exclusive subpopulations that are responsible for seeding normal tissues (Gr-1−/CCR2−/CX3CR1high) or responding to sites of inflammation (Gr-1+/CCR2+/CX3CR1lo). Gr-1+ monocytes are recruited to the site of infection during the early stages of immune response to the intracellular pathogen Toxoplasma gondii. A murine model of toxoplasmosis was thus used to examine the importance of Gr-1+ monocytes in the control of disseminated parasitic infection in vivo. The recruitment of Gr-1+ monocytes was intimately associated with the ability to suppress early parasite replication at the site of inoculation. Infection of CCR2−/− and MCP-1−/− mice with typically nonlethal, low doses of T. gondii resulted in the abrogated recruitment of Gr-1+ monocytes. The failure to recruit Gr-1+ monocytes resulted in greatly enhanced mortality despite the induction of normal Th1 cell responses leading to high levels of IL-12, TNF-α, and IFN-γ. The profound susceptibility of CCR2−/− mice establishes Gr-1+ monocytes as necessary effector cells in the resistance to acute toxoplasmosis and suggests that the CCR2-dependent recruitment of Gr-1+ monocytes may be an important general mechanism for resistance to intracellular pathogens. PMID:15928200

Minocycline Inhibition of Monocyte Activation Correlates with Neuronal Protection in SIV NeuroAIDS

PubMed Central

Campbell, Jennifer H.; Burdo, Tricia H.; Autissier, Patrick; Bombardier, Jeffrey P.; Westmoreland, Susan V.; Soulas, Caroline; González, R. Gilberto; Ratai, Eva-Maria; Williams, Kenneth C.

2011-01-01

Background Minocycline is a tetracycline antibiotic that has been proposed as a potential conjunctive therapy for HIV-1 associated cognitive disorders. Precise mechanism(s) of minocycline's functions are not well defined. Methods Fourteen rhesus macaques were SIV infected and neuronal metabolites measured by proton magnetic resonance spectroscopy (1H MRS). Seven received minocycline (4 mg/kg) daily starting at day 28 post-infection (pi). Monocyte expansion and activation were assessed by flow cytometry, cell traffic to lymph nodes, CD16 regulation, viral replication, and cytokine production were studied. Results Minocycline treatment decreased plasma virus and pro-inflammatory CD14+CD16+ and CD14loCD16+ monocytes, and reduced their expression of CD11b, CD163, CD64, CCR2 and HLA-DR. There was reduced recruitment of monocyte/macrophages and productively infected cells in axillary lymph nodes. There was an inverse correlation between brain NAA/Cr (neuronal injury) and circulating CD14+CD16+ and CD14loCD16+ monocytes. Minocycline treatment in vitro reduced SIV replication CD16 expression on activated CD14+CD16+ monocytes, and IL-6 production by monocytes following LPS stimulation. Conclusion Neuroprotective effects of minocycline are due in part to reduction of activated monocytes, monocyte traffic. Mechanisms for these effects include CD16 regulation, reduced viral replication, and inhibited immune activation. PMID:21494695

Periodontitis-activated monocytes/macrophages cause aortic inflammation

PubMed Central

Miyajima, Shin-ichi; Naruse, Keiko; Kobayashi, Yasuko; Nakamura, Nobuhisa; Nishikawa, Toru; Adachi, Kei; Suzuki, Yuki; Kikuchi, Takeshi; Mitani, Akio; Mizutani, Makoto; Ohno, Norikazu; Noguchi, Toshihide; Matsubara, Tatsuaki

2014-01-01

A relationship between periodontal disease and atherosclerosis has been suggested by epidemiological studies. Ligature-induced experimental periodontitis is an adequate model for clinical periodontitis, which starts from plaque accumulation, followed by inflammation in the periodontal tissue. Here we have demonstrated using a ligature-induced periodontitis model that periodontitis activates monocytes/macrophages, which subsequently circulate in the blood and adhere to vascular endothelial cells without altering the serum TNF-α concentration. Adherent monocytes/macrophages induced NF-κB activation and VCAM-1 expression in the endothelium and increased the expression of the TNF-α signaling cascade in the aorta. Peripheral blood-derived mononuclear cells from rats with experimental periodontitis showed enhanced adhesion and increased NF-κB/VCAM-1 in cultured vascular endothelial cells. Our results suggest that periodontitis triggers the initial pathogenesis of atherosclerosis, inflammation of the vasculature, through activating monocytes/macrophages. PMID:24893991

Ebola Virus Disease Is Characterized by Poor Activation and Reduced Levels of Circulating CD16+ Monocytes.

PubMed

Lüdtke, Anja; Ruibal, Paula; Becker-Ziaja, Beate; Rottstegge, Monika; Wozniak, David M; Cabeza-Cabrerizo, Mar; Thorenz, Anja; Weller, Romy; Kerber, Romy; Idoyaga, Juliana; Magassouba, N'Faly; Gabriel, Martin; Günther, Stephan; Oestereich, Lisa; Muñoz-Fontela, César

2016-10-15

A number of previous studies have identified antigen-presenting cells (APCs) as key targets of Ebola virus (EBOV), but the role of APCs in human Ebola virus disease (EVD) is not known. We have evaluated the phenotype and kinetics of monocytes, neutrophils, and dendritic cells (DCs) in peripheral blood of patients for whom EVD was diagnosed by the European Mobile Laboratory in Guinea. Acute EVD was characterized by reduced levels of circulating nonclassical CD16 + monocytes with a poor activation profile. In survivors, CD16 + monocytes were activated during recovery, coincident with viral clearance, suggesting an important role of this cell subset in EVD pathophysiology. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Monocytes Induce STAT3 Activation in Human Mesenchymal Stem Cells to Promote Osteoblast Formation

PubMed Central

Nicolaidou, Vicky; Wong, Mei Mei; Redpath, Andia N.; Ersek, Adel; Baban, Dilair F.; Williams, Lynn M.; Cope, Andrew P.; Horwood, Nicole J.

2012-01-01

A major therapeutic challenge is how to replace bone once it is lost. Bone loss is a characteristic of chronic inflammatory and degenerative diseases such as rheumatoid arthritis and osteoporosis. Cells and cytokines of the immune system are known to regulate bone turnover by controlling the differentiation and activity of osteoclasts, the bone resorbing cells. However, less is known about the regulation of osteoblasts (OB), the bone forming cells. This study aimed to investigate whether immune cells also regulate OB differentiation. Using in vitro cell cultures of human bone marrow-derived mesenchymal stem cells (MSC), it was shown that monocytes/macrophages potently induced MSC differentiation into OBs. This was evident by increased alkaline phosphatase (ALP) after 7 days and the formation of mineralised bone nodules at 21 days. This monocyte-induced osteogenic effect was mediated by cell contact with MSCs leading to the production of soluble factor(s) by the monocytes. As a consequence of these interactions we observed a rapid activation of STAT3 in the MSCs. Gene profiling of STAT3 constitutively active (STAT3C) infected MSCs using Illumina whole human genome arrays showed that Runx2 and ALP were up-regulated whilst DKK1 was down-regulated in response to STAT3 signalling. STAT3C also led to the up-regulation of the oncostatin M (OSM) and LIF receptors. In the co-cultures, OSM that was produced by monocytes activated STAT3 in MSCs, and neutralising antibodies to OSM reduced ALP by 50%. These data indicate that OSM, in conjunction with other mediators, can drive MSC differentiation into OB. This study establishes a role for monocyte/macrophages as critical regulators of osteogenic differentiation via OSM production and the induction of STAT3 signalling in MSCs. Inducing the local activation of STAT3 in bone cells may be a valuable tool to increase bone formation in osteoporosis and arthritis, and in localised bone remodelling during fracture repair. PMID:22802946

Integrin αMβ2 is differently expressed by subsets of human osteoclast precursors and mediates adhesion of classical monocytes to bone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprangers, Sara, E-mail: s.l.sprangers@acta.nl; Schoenmaker, Ton, E-mail: t.schoenmaker@acta.nl; Department of Periodontology, Academic Centre for Dentistry Amsterdam

Bone-degrading osteoclasts are formed through fusion of their monocytic precursors. In the population of human peripheral blood monocytes, three distinct subsets have been identified: classical, intermediate and non-classical monocytes. We have previously shown that when the monocyte subsets are cultured on bone, significantly more osteoclasts are formed from classical monocytes than from intermediate or non-classical monocytes. Considering that this difference does not exist when monocyte subsets are cultured on plastic, we hypothesized that classical monocytes adhere better to the bone surface compared to intermediate and non-classical monocytes. To investigate this, the different monocyte subsets were isolated from human peripheral bloodmore » and cultured on slices of human bone in the presence of the cytokine M-CSF. We found that classical monocytes adhere better to bone due to a higher expression of the integrin αMβ2 and that their ability to attach to bone is significantly decreased when the integrin is blocked. This suggests that integrin αMβ2 mediates attachment of osteoclast precursors to bone and thereby enables the formation of osteoclasts.« less

Herpes simplex virus antigens directly activate NK cells via TLR2, thus facilitating their presentation to CD4 T lymphocytes.

PubMed

Kim, Min; Osborne, Naomi R; Zeng, Weiguang; Donaghy, Heather; McKinnon, Kay; Jackson, David C; Cunningham, Anthony L

2012-05-01

NK cells infiltrate human herpetic lesions, but their role has been underexplored. HSV can stimulate innate immune responses via surface TLR2, which is expressed on monocyte-derived dendritic cells (DCs) and NK cells. In this study, UV-inactivated HSV1/2 and immunodominant HSV2 glycoprotein D peptides conjugated to the TLR2 agonist dipalmitoyl-S-glyceryl cysteine stimulated CD4 T lymphocyte IFN-γ responses within PBMCs or in coculture with monocyte-derived DCs. NK cells contributed markedly to the PBMC responses. Furthermore, NK cells alone were activated directly by both Ags, also upregulating HLA-DR and HLA-DQ and then they activated autologous CD4 T lymphocytes. Using Transwells, Ag-stimulated NK cells and CD4 T lymphocytes were shown to interact through both cell-to-cell contact and cytokines, differing in relative importance in different donors. A distinct immunological synapse between Ag-stimulated NK cells and CD4 T lymphocytes was observed, indicating the significance of their cell-to-cell contact. A large proportion (57%) of NK cells was also in contact with CD4 T lymphocytes in the dermal infiltrate of human recurrent herpetic lesions. Thus, NK cells stimulated by TLR2-activating HSV Ags can present Ag alone or augment the role of DCs in vitro and perhaps in herpetic lesions or draining lymph nodes. In addition to DCs, NK cells should be considered as targets for adjuvants during HSV vaccine development.

Oral Wild-Type Salmonella Typhi Challenge Induces Activation of Circulating Monocytes and Dendritic Cells in Individuals Who Develop Typhoid Disease.

PubMed

Toapanta, Franklin R; Bernal, Paula J; Fresnay, Stephanie; Darton, Thomas C; Jones, Claire; Waddington, Claire S; Blohmke, Christoph J; Dougan, Gordon; Angus, Brian; Levine, Myron M; Pollard, Andrew J; Sztein, Marcelo B

2015-06-01

A new human oral challenge model with wild-type Salmonella Typhi (S. Typhi) was recently developed. In this model, ingestion of 104 CFU of Salmonella resulted in 65% of subjects developing typhoid fever (referred here as typhoid diagnosis -TD-) 5-10 days post-challenge. TD criteria included meeting clinical (oral temperature ≥38°C for ≥12 h) and/or microbiological (S. Typhi bacteremia) endpoints. One of the first lines of defense against pathogens are the cells of the innate immune system (e.g., monocytes, dendritic cells -DCs-). Various changes in circulating monocytes and DCs have been described in the murine S. Typhimurium model; however, whether similar changes are present in humans remains to be explored. To address these questions, a subset of volunteers (5 TD and 3 who did not develop typhoid despite oral challenge -NoTD-) were evaluated for changes in circulating monocytes and DCs. Expression of CD38 and CD40 were upregulated in monocytes and DCs in TD volunteers during the disease days (TD-0h to TD-96h). Moreover, integrin α4β7, a gut homing molecule, was upregulated on monocytes but not DCs. CD21 upregulation was only identified in DCs. These changes were not observed among NoTD volunteers despite the same oral challenge. Moreover, monocytes and DCs from NoTD volunteers showed increased binding to S. Typhi one day after challenge. These monocytes showed phosphorylation of p38MAPK, NFkB and Erk1/2 upon stimulation with S. Typhi-LPS-QDot micelles. In contrast, monocytes from TD volunteers showed only a moderate increase in S. Typhi binding 48 h and 96 h post-TD, and only Erk1/2 phosphorylation. This is the first study to describe different activation and migration profiles, as well as differential signaling patterns, in monocytes and DCs which relate directly to the clinical outcome following oral challenge with wild type S. Typhi.

Compartmentalisation of innate immune responses in the central nervous system during cryptococcal meningitis/HIV co-infection

PubMed Central

NARANBHAI, Vivek; CHANG, Christina C.; DURGIAH, Raveshni; OMARJEE, Saleha; LIM, Andrew; MOOSA, Mahomed-Yunus S.; ELLIOT, Julian H.; NDUNG’U, Thumbi; LEWIN, Sharon R.; FRENCH, Martyn A.; CARR, William H.

2014-01-01

Objective The role of innate immunity in pathogenesis of cryptococcal meningitis (CM) is unclear. We hypothesised that NK cell and monocyte responses are central nervous system (CNS) compartmentalised, and altered by anti-fungal therapy and combination antiretroviral therapy (cART) during CM/HIV co-infection. Design Sub-study of a prospective cohort study of adults with CM/HIV co-infection in Durban, South Africa. Methods We used multi-parametric flow cytometry to study compartmentalisation of subsets, activation (CD69pos), CXCR3 and CX3CR1 expression and cytokine secretion of NK cells and monocytes in freshly collected blood and cerebrospinal fluid (CSF) at diagnosis (n=23), completion of anti-fungal therapy induction (n=19) and after a further 4 weeks of cART (n=9). Results Relative to blood, CSF was enriched with CD56bright (immunoregulatory) NK cells (p=0.0004). At enrolment, CXCR3 expression was more frequent amongst blood CD56bright than either blood CD56dim (p<0.0001) or CSF CD56bright (p=0.0002) NK cells. Anti-fungal therapy diminished blood (p<0.05) but not CSF CXCR3pos NK cell proportions nor CX3CR1pos NK cell proportions. CD56bright and CD56dim NK cells were more activated in CSF than blood (p<0.0001). Anti-fungal therapy induction reduced CD56dim NK cell activation in CSF (p=0.02). Activation of blood CD56bright and CD56dim NK cells was diminished following cART commencement (p<0.0001, p=0.03). Immunoregulatory NK cells in CSF tended to secrete higher levels of CXCL10 (p=0.06) and lower levels of TNF-α (p=0.06) than blood immunoregulatory NK cells. CSF was enriched with non-classical monocytes (p=0.001), but anti-fungal therapy restored proportions of classical monocytes (p=0.007). Conclusions These results highlight CNS activation, trafficking and function of NK cells and monocytes in CM/HIV and implicate immunoregulatory NK cells and pro-inflammatory monocytes as potential modulators of CM pathogenesis during HIV co-infection. PMID:24451162

Lysozyme activity and nitroblue-tetrazolium reduction in leukaemic cells

PubMed Central

Catovsky, D.; Galton, D. A. G.

1973-01-01

The cytochemical methods for lysozyme and nitroblue-tetrazolium reduction have been used to study the blast cells of acute myeloid leukaemia. Both proved useful in characterizing the cases with predominant monocytic differentiation. The demonstration of lysozyme activity helped to define two main groups: (a) with predominantly lysozyme-negative cells (myeloblastic-promyelocytic), and (b) with considerable numbers of positive cells (monoblastic-monocytic). In addition this test was also of value in the differentiation of other leukaemic disorders. Reduction of nitroblue-tetrazolium was also a feature of monocytic differentiation. The combination of these two methods with those for myeloperoxidase and non-specific esterase activity contributes to the cytological characterization of acute myeloid leukaemia. Images PMID:4511938

Comparison of monocyte-derived dendritic cells from colorectal cancer patients, non-small-cell-lung-cancer patients and healthy donors.

PubMed

Kvistborg, P; Bechmann, C M; Pedersen, A W; Toh, H C; Claesson, M H; Zocca, M B

2009-12-11

Dendritic cells (DCs) are bone marrow-derived professional antigen presenting cells. Due to their role as potent inducers of immune responses, these cells are widely used as adjuvant in experimental clinical settings for cancer immune therapy. We have developed a DC-based vaccine using autologous blood monocytes loaded with allogeneic tumor cell lysate rich in cancer/testis antigens. This vaccine has at present been tested for activity in three phase II clinical trials including two cohorts of patients with advanced colorectal cancer (CRC) and one cohort of patients with advanced non-small-cell-lung-cancer (NSCLC). In the present paper we retrospectively compare the maturation profile based on surface marker expression on DCs generated from the three patient cohorts and between cancer patient cohorts and a cohort of healthy donors. Vaccines were generated under cGMP conditions and phenotypic profiles of DC were analyzed by flow cytometry and the obtained data were used as a basis to set guideline values for our quality control of GMP produced DC vaccines. Each vaccine batch was analyzed for the expression of the surface maturation and differentiation molecules CD14, CD1a, CD83, CD86, MHC class II and CCR7, and the optimal expression pattern is considered as CD14(low), CD1a, CD83(high), CD86(high), MHC class II(high) and CCR7(high). In accordance with data from other studies including other types of cancer patients, especially breast cancer patients, we found that the maturation status of the DC batches depends on cancer type and correlates with clinical status of cancer patients included.

Single-cell RNA-seq reveals new types of human blood dendritic cells, monocytes and progenitors

PubMed Central

Villani, Alexandra-Chloé; Satija, Rahul; Reynolds, Gary; Sarkizova, Siranush; Shekhar, Karthik; Fletcher, James; Griesbeck, Morgane; Butler, Andrew; Zheng, Shiwei; Lazo, Suzan; Jardine, Laura; Dixon, David; Stephenson, Emily; Nilsson, Emil; Grundberg, Ida; McDonald, David; Filby, Andrew; Li, Weibo; De Jager, Philip L.; Rozenblatt-Rosen, Orit; Lane, Andrew A.; Haniffa, Muzlifah; Regev, Aviv; Hacohen, Nir

2017-01-01

Dendritic cells (DCs) and monocytes play a central role in pathogen sensing, phagocytosis and antigen presentation and consist of multiple specialized subtypes. However, their identities and interrelationships are not fully understood. Using unbiased single-cell RNA sequencing (RNA-seq) of ~2400 cells, we identified six human DCs and four monocyte subtypes in human blood. Our study reveals: a new DC subset that shares properties with plasmacytoid DCs (pDCs) but potently activates T cells, thus redefining pDCs; a new subdivision within the CD1C+ subset of DCs; the relationship between blastic plasmacytoid DC neoplasia cells and healthy DCs; and circulating progenitor of conventional DCs (cDCs). Our revised taxonomy will enable more accurate functional and developmental analyses as well as immune monitoring in health and disease. PMID:28428369

Dexamethasone enhances interaction of endogenous annexin 1 with L-selectin and triggers shedding of L-selectin in the monocytic cell line U-937.

PubMed

de Coupade, Catherine; Solito, Egle; Levine, Jon D

2003-09-01

(1) L-selectin, constitutively expressed by leukocytes, is involved in the initial binding of leukocytes to activated endothelium. Anti-inflammatory drugs like glucocorticoids can induce shedding of L-selectin, but the mechanism is still unknown. Annexin 1, a protein whose synthesis and externalization/secretion are induced during the inflammatory response, has been proposed as a mediator of the anti-inflammatory actions of glucocorticoids. (2) The monocytic cell line U-937 strongly expresses Annexin 1 after 24 h of phorbol 12-myristate 13-acetate (PMA, 1 nm) treatment and externalizes/releases the protein after additional 16 h of dexamethasone (1 microm) treatment. (3) This study investigated the possible regulation of cell surface L-selectin shedding by endogenous Annexin 1, and its role in glucocorticoid-induced L-selectin shedding in the U-937 cell line. (4) PMA- and dexamethasone treatment-induced L-selectin shedding was potentially mediated by Annexin 1, since neutralizing antibodies against Annexin 1 reduced dexamethasone- and Annexin 1-induced shedding. (5) Immunoprecipitation and binding assays provided support for the suggestion that this effect could be mediated by an interaction between externalized Annexin 1 and L-selectin. Such interaction involved the N-terminal domain of Annexin 1 and was calcium-dependent. Confocal microscopy studies demonstrated increased colocalization of Annexin 1 and L-selectin on the cell surface. (6) Overall, our study provides new insights into the potential role of endogenous ANXA1 as a mediator of dexamethasone-induced L-selectin shedding, which may contribute to the anti-inflammatory activity of glucocorticoids.

Immune regulation by CD40-CD40-l interactions - 2; Y2K update.

PubMed

van Kooten, C

2000-11-01

CD40 is a cell surface receptor, which belongs to the TNF-R family, and which was first identified and functionally characterized on B lymphocytes. However, in recent years it has become clear that CD40 is expressed much broader, including expression on monocytes, dendritic cells, endothelial cells and epithelial cells. Therefore it is now thought that CD40 plays a more general role in immune regulation. The present paper reviews recent developments in this field of research, with main emphasis on CD40 signal transduction and on in vivo functions of CD40/CD40-L interactions.

Mesenchymal Stem Cells Induce Expression of CD73 in Human Monocytes In Vitro and in a Swine Model of Myocardial Infarction In Vivo.

PubMed

Monguió-Tortajada, Marta; Roura, Santiago; Gálvez-Montón, Carolina; Franquesa, Marcella; Bayes-Genis, Antoni; Borràs, Francesc E

2017-01-01

The ectoenzymes CD39 and CD73 regulate the purinergic signaling through the hydrolysis of adenosine triphosphate (ATP)/ADP to AMP and to adenosine (Ado), respectively. This shifts the pro-inflammatory milieu induced by extracellular ATP to the anti-inflammatory regulation by Ado. Mesenchymal stem cells (MSCs) have potent immunomodulatory capabilities, including monocyte modulation toward an anti-inflammatory phenotype aiding tissue repair. In vitro , we observed that human cardiac adipose tissue-derived MSCs (cATMSCs) and umbilical cord MSCs similarly polarize monocytes toward a regulatory M2 phenotype, which maintained the expression of CD39 and induced expression of CD73 in a cell contact dependent fashion, correlating with increased functional activity. In addition, the local treatment with porcine cATMSCs using an engineered bioactive graft promoted the in vivo CD73 expression on host monocytes in a swine model of myocardial infarction. Our results suggest the upregulation of ectonucleotidases on MSC-conditioned monocytes as an effective mechanism to amplify the long-lasting immunomodulatory and healing effects of MSCs delivery.

Differential monocyte responses to TLR ligands in children with autism spectrum disorders

PubMed Central

Enstrom, Amanda M; Onore, Charity E; Van de Water, Judy A; Ashwood, Paul

2010-01-01

Autism spectrum disorders (ASD) are characterized by impairment in social interactions, communication deficits, and restricted repetitive interests and behaviors. Recent evidence has suggested that impairments of innate immunity may play an important role in ASD. To test this hypothesis, we isolated peripheral blood monocytes from 17 children with ASD and 16 age-matched typically developing (TD) controls and stimulated these cell cultures in vitro with distinct toll-like receptors (TLR) ligands: TLR2 (lipoteichoic acid; LTA), TLR3 (poly I:C), TLR4 (lipopolysaccharide; LPS), TLR5 (flagellin) and TLR9 (CpG-B). Supernatants were harvested from the cell cultures and pro-inflammatory cytokine responses for IL-1β, IL-6, IL-8, TNFα, MCP-1, and GM-CSF were determined by multiplex Luminex analysis. After in vitro challenge with TLR ligands, differential cytokine responses were observed in monocyte cultures from children with ASD compared with TD control children. In particular, there was a marked increase in pro-inflammatory IL-1β, IL-6 and TNFα responses following TLR2, and IL-1β response following TLR4 stimulation in monocyte cultures from children with ASD (p<0.04). Conversely, following TLR9 stimulation there was a decrease in IL-1β, IL-6, GM-CSF and TNFα responses in monocyte cell cultures from children with ASD compared with controls (p<0.05). These data indicate that, monocyte cultures from children with ASD are more responsive to signaling via select TLRs. As monocytes are key regulators of the immune response, dysfunction in the response of these cells could result in long-term immune alterations in children with ASD that may lead to the development of adverse neuroimmune interactions and could play a role in the pathophysiology observed in ASD. PMID:19666104

Differential monocyte responses to TLR ligands in children with autism spectrum disorders.

PubMed

Enstrom, Amanda M; Onore, Charity E; Van de Water, Judy A; Ashwood, Paul

2010-01-01

Autism spectrum disorders (ASD) are characterized by impairment in social interactions, communication deficits, and restricted repetitive interests and behaviors. Recent evidence has suggested that impairments of innate immunity may play an important role in ASD. To test this hypothesis, we isolated peripheral blood monocytes from 17 children with ASD and 16 age-matched typically developing (TD) controls and stimulated these cell cultures in vitro with distinct toll-like receptors (TLR) ligands: TLR 2 (lipoteichoic acid; LTA), TLR 3 (poly I:C), TLR 4 (lipopolysaccharide; LPS), TLR 5 (flagellin), and TLR 9 (CpG-B). Supernatants were harvested from the cell cultures and pro-inflammatory cytokine responses for IL-1beta, IL-6, IL-8, TNFalpha, MCP-1, and GM-CSF were determined by multiplex Luminex analysis. After in vitro challenge with TLR ligands, differential cytokine responses were observed in monocyte cultures from children with ASD compared with TD control children. In particular, there was a marked increase in pro-inflammatory IL-1beta, IL-6, and TNFalpha responses following TLR 2, and IL-1beta response following TLR 4 stimulation in monocyte cultures from children with ASD (p<0.04). Conversely, following TLR 9 stimulation there was a decrease in IL-1beta, IL-6, GM-CSF, and TNFalpha responses in monocyte cell cultures from children with ASD compared with controls (p<0.05). These data indicate that, monocyte cultures from children with ASD are more responsive to signaling via select TLRs. As monocytes are key regulators of the immune response, dysfunction in the response of these cells could result in long-term immune alterations in children with ASD that may lead to the development of adverse neuroimmune interactions and could play a role in the pathophysiology observed in ASD.

Transport of cargo from periphery to brain by circulating monocytes.

PubMed

Cintron, Amarallys F; Dalal, Nirjari V; Dooyema, Jeromy; Betarbet, Ranjita; Walker, Lary C

2015-10-05

The misfolding and aggregation of the Aβ peptide - a fundamental event in the pathogenesis of Alzheimer׳s disease - can be instigated in the brains of experimental animals by the intracranial infusion of brain extracts that are rich in aggregated Aβ. Recent experiments have found that the peripheral (intraperitoneal) injection of Aβ seeds induces Aβ deposition in the brains of APP-transgenic mice, largely in the form of cerebral amyloid angiopathy. Macrophage-type cells normally are involved in pathogen neutralization and antigen presentation, but under some circumstances, circulating monocytes have been found to act as vectors for the transport of pathogenic agents such as viruses and prions. The present study assessed the ability of peripheral monocytes to transport Aβ aggregates from the peritoneal cavity to the brain. Our initial experiments showed that intravenously delivered macrophages that had previously ingested fluorescent nanobeads as tracers migrate primarily to peripheral organs such as spleen and liver, but that a small number also reach the brain parenchyma. We next injected CD45.1-expressing monocytes from donor mice intravenously into CD45.2-expressing host mice; after 24h, analysis by fluorescence-activated cell sorting (FACS) and histology confirmed that some CD45.1 monocytes enter the brain, particularly in the superficial cortex and around blood vessels. When the donor monocytes are first exposed to Aβ-rich brain extracts from human AD cases, a subset of intravenously delivered Aβ-containing cells migrate to the brain. These experiments indicate that, in mouse models, circulating monocytes are potential vectors by which exogenously delivered, aggregated Aβ travels from periphery to brain, and more generally support the hypothesis that macrophage-type cells can participate in the dissemination of proteopathic seeds. Copyright © 2015 Elsevier B.V. All rights reserved.

Targeting the latent cytomegalovirus reservoir with an antiviral fusion toxin protein

PubMed Central

Krishna, B. A.; Spiess, K.; Poole, E. L.; Lau, B.; Voigt, S.; Kledal, T. N.; Rosenkilde, M. M.; Sinclair, J. H.

2017-01-01

Reactivation of human cytomegalovirus (HCMV) in transplant recipients can cause life-threatening disease. Consequently, for transplant recipients, killing latently infected cells could have far-reaching clinical benefits. In vivo, myeloid cells and their progenitors are an important site of HCMV latency, and one viral gene expressed by latently infected myeloid cells is US28. This viral gene encodes a cell surface G protein-coupled receptor (GPCR) that binds chemokines, triggering its endocytosis. We show that the expression of US28 on the surface of latently infected cells allows monocytes and their progenitor CD34+ cells to be targeted and killed by F49A-FTP, a highly specific fusion toxin protein that binds this viral GPCR. As expected, this specific targeting of latently infected cells by F49A-FTP also robustly reduces virus reactivation in vitro. Consequently, such specific fusion toxin proteins could form the basis of a therapeutic strategy for eliminating latently infected cells before haematopoietic stem cell transplantation. PMID:28148951

Systems Biology Reveals Cigarette Smoke-Induced Concentration-Dependent Direct and Indirect Mechanisms That Promote Monocyte-Endothelial Cell Adhesion.

PubMed

Poussin, Carine; Laurent, Alexandra; Peitsch, Manuel C; Hoeng, Julia; De Leon, Hector

2015-10-01

Cigarette smoke (CS) affects the adhesion of monocytes to endothelial cells, a critical step in atherogenesis. Using an in vitro adhesion assay together with innovative computational systems biology approaches to analyze omics data, our study aimed at investigating CS-induced mechanisms by which monocyte-endothelial cell adhesion is promoted. Primary human coronary artery endothelial cells (HCAECs) were treated for 4 h with (1) conditioned media of human monocytic Mono Mac-6 (MM6) cells preincubated with low or high concentrations of aqueous CS extract (sbPBS) from reference cigarette 3R4F for 2 h (indirect treatment, I), (2) unconditioned media similarly prepared without MM6 cells (direct treatment, D), or (3) freshly generated sbPBS (fresh direct treatment, FD). sbPBS promoted MM6 cells-HCAECs adhesion following I and FD, but not D. In I, the effect was mediated at a low concentration through activation of vascular inflammation processes promoted in HCAECs by a paracrine effect of the soluble mediators secreted by sbPBS-treated MM6 cells. Tumor necrosis factor α (TNFα), a major inducer, was actually shed by unstable CS compound-activated TNFα-converting enzyme. In FD, the effect was triggered at a high concentration that also induced some toxicity. This effect was mediated through an yet unknown mechanism associated with a stress damage response promoted in HCAECs by unstable CS compounds present in freshly generated sbPBS, which had decayed in D unconditioned media. Aqueous CS extract directly and indirectly promotes monocytic cell-endothelial cell adhesion in vitro via distinct concentration-dependent mechanisms. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

MLN4924 sensitizes monocytes and maturing dendritic cells for TNF-dependent and -independent necroptosis.

PubMed

El-Mesery, Mohamed; Seher, Axel; Stühmer, Thorsten; Siegmund, Daniela; Wajant, Harald

2015-03-01

MLN4924 prevents the formation of active cullin-RING ubiquitin ligase complexes and thus inhibits NF-κB signalling. Here, we evaluated the effects of this compound on monocytes and dendritic cells (DCs). Monocytes and DCs were challenged with TNF or LPS in the presence and absence of MLN4924. The effects of MLN4924 on cellular viability, pro-inflammatory gene induction and DC maturation were investigated using the MTT assay, elisa and FACS analysis. Mechanisms of cell death induction were evaluated by using inhibitors of caspases, RIPK1 and MLKL. MLN4924 inhibited NF-κB activation and sensitized monocytes and immature DCs (iDCs) for TNFR1-induced cell death. Neither the caspase inhibitor zVAD-fmk, the RIPK1 inhibitor necrostatin-1 (nec-1) nor the MLKL inhibitor necrosulfonamide (NSA) alone prevented TNF-induced cell death. A combination of zVAD-fmk and nec-1 or NSA, however, rescued monocytes and iDCs from MLN4924/TNF-induced cell death indicating that MLN4924 affects anti-apoptotic and anti-necrotic activities in TNFR1 signalling. MLN4924 also converted the response of iDCs to LPS from maturation to cell death. LPS-induced cell death in MLN4924-treated iDCs was again only effectively blocked by cotreatment with zVAD-fmk and nec-1 or NSA. Noteworthy, MLN4924/LPS-induced cell death was almost completely independent of endogenous TNF. MLN4924 also strongly inhibited maturation and activation of iDCs that were rescued from cell death by zVAD-fmk and nec-1. Our data reveal a strong dual suppressive effect of MLN4924 on DC activity. The targeting of NAE by MLN4924 could be a new way to treat inflammatory diseases. © 2014 The British Pharmacological Society.

Ureaplasma isolates stimulate pro-inflammatory CC chemokines and matrix metalloproteinase-9 in neonatal and adult monocytes

PubMed Central

Silwedel, Christine; Fehrholz, Markus; Henrich, Birgit; Waaga-Gasser, Ana Maria; Claus, Heike; Speer, Christian P.

2018-01-01

Being generally regarded as commensal bacteria, the pro-inflammatory capacity of Ureaplasma species has long been debated. Recently, we confirmed Ureaplasma–driven pro-inflammatory cytokine responses and a disturbance of cytokine equilibrium in primary human monocytes in vitro. The present study addressed the expression of CC chemokines and matrix metalloproteinase-9 (MMP-9) in purified term neonatal and adult monocytes stimulated with serovar 8 of Ureaplasma urealyticum (Uu) and serovar 3 of U. parvum (Up). Using qRT-PCR and multi-analyte immunoassay, we assessed mRNA and protein expression of the monocyte chemotactic proteins 1 and 3 (MCP-1/3), the macrophage inflammatory proteins 1α and 1β (MIP-1α/β) as well as MMP-9. For the most part, both isolates stimulated mRNA expression of all given chemokines and MMP-9 in cord blood and adult monocytes (p<0.05 and p<0.01). These results were paralleled by Uu and Up-induced secretion of MCP-1 protein in both cells (neonatal: p<0.01, adult: p<0.05 and p<0.01). Release of MCP-3, MIP-1α, MIP-1β and MMP-9 was enhanced upon exposure to Up (neonatal: p<0.05, p<0.01 and p<0.001, respectively; adult: p<0.05). Co-stimulation of LPS-primed monocytes with Up increased LPS-induced MCP-1 release in neonatal cells (p<0.05) and aggravated LPS-induced MMP-9 mRNA in both cell subsets (neonatal: p<0.05, adult: p<0.01). Our results document considerable expression of pro-inflammatory CC chemokines and MMP-9 in human monocytes in response to Ureaplasma isolates in vitro, adding to our previous data. Findings from co-stimulated cells indicate that Ureaplasma may modulate monocyte immune responses to a second stimulus. PMID:29558521

GM-CSF Monocyte-Derived Cells and Langerhans Cells As Part of the Dendritic Cell Family

PubMed Central

Lutz, Manfred B.; Strobl, Herbert; Schuler, Gerold; Romani, Nikolaus

2017-01-01

Dendritic cells (DCs) and macrophages (Mph) share many characteristics as components of the innate immune system. The criteria to classify the multitude of subsets within the mononuclear phagocyte system are currently phenotype, ontogeny, transcription patterns, epigenetic adaptations, and function. More recently, ontogenetic, transcriptional, and proteomic research approaches uncovered major developmental differences between Flt3L-dependent conventional DCs as compared with Mphs and monocyte-derived DCs (MoDCs), the latter mainly generated in vitro from murine bone marrow-derived DCs (BM-DCs) or human CD14+ peripheral blood monocytes. Conversely, in vitro GM-CSF-dependent monocyte-derived Mphs largely resemble MoDCs whereas tissue-resident Mphs show a common embryonic origin from yolk sac and fetal liver with Langerhans cells (LCs). The novel ontogenetic findings opened discussions on the terminology of DCs versus Mphs. Here, we bring forward arguments to facilitate definitions of BM-DCs, MoDCs, and LCs. We propose a group model of terminology for all DC subsets that attempts to encompass both ontogeny and function. PMID:29109731

Acetylcholine-producing NK cells attenuate CNS inflammation via modulation of infiltrating monocytes/macrophages.

PubMed

Jiang, Wei; Li, Daojing; Han, Ranran; Zhang, Chao; Jin, Wei-Na; Wood, Kristofer; Liu, Qiang; Shi, Fu-Dong; Hao, Junwei

2017-07-25

The nonneural cholinergic system of immune cells is pivotal for the maintenance of immunological homeostasis. Here we demonstrate the expression of choline acetyltransferase (ChAT) and cholinergic enzymes in murine natural killer (NK) cells. The capacity for acetylcholine synthesis by NK cells increased markedly under inflammatory conditions such as experimental autoimmune encephalomyelitis (EAE), in which ChAT expression escalated along with the maturation of NK cells. ChAT + and ChAT - NK cells displayed distinctive features in terms of cytotoxicity and chemokine/cytokine production. Transfer of ChAT + NK cells into the cerebral ventricles of CX3CR1 -/- mice reduced brain and spinal cord damage after EAE induction, and decreased the numbers of CNS-infiltrating CCR2 + Ly6C hi monocytes. ChAT + NK cells killed CCR2 + Ly6C hi monocytes directly via the disruption of tolerance and inhibited the production of proinflammatory cytokines. Interestingly, ChAT + NK cells and CCR2 + Ly6C hi monocytes formed immune synapses; moreover, the impact of ChAT + NK cells was mediated by α7-nicotinic acetylcholine receptors. Finally, the NK cell cholinergic system up-regulated in response to autoimmune activation in multiple sclerosis, perhaps reflecting the severity of disease. Therefore, this study extends our understanding of the nonneural cholinergic system and the protective immune effect of acetylcholine-producing NK cells in autoimmune diseases.

Accessory cells with a veiled morphology and movement pattern generated from monocytes after avoidance of plastic adherence and of NADPH oxidase activation. A comparison with GM-CSF/IL-4-induced monocyte-derived dendritic cells.

PubMed

Ruwhof, Cindy; Canning, Martha O; Grotenhuis, Kristel; de Wit, Harm J; Florencia, Zenovia Z; de Haan-Meulman, Meeny; Drexhage, Hemmo A

2002-07-01

Veiled cells (VC) present in afferent lymph transport antigen from the periphery to the draining lymph nodes. Although VC in lymph form a heterogeneous population, some of the cells clearly belong on morphological grounds to the Langerhans cell (LC)/ dendritic cell (DC) series. Here we show that culturing monocytes for 24 hrs while avoiding plastic adherence (polypropylene tubes) and avoiding the activation of NADPH oxidase (blocking agents) results in the generation of a population of veiled accessory cells. The generated VC were actively moving cells like lymph-borne VC in vivo. The monocyte (mo)-derived VC population existed of CD14(dim/-) and CD14(brighT) cells. Of these the CD14(dim/-) VC were as good in stimulating allogeneic T cell proliferation as immature DC (iDC) obtained after one week of adherent culture of monocytes in granulocyte-macrophage-colony stimulating factor (GM-CSF)/interleukin (IL)-4. This underscores the accessory cell function of the mo-derived CD14(dim/-) VC. Although the CD14(dim/-)VC had a modest expression of the DC-specific marker CD83 and were positive for S100, expression of the DC-specific markers CD1a, Langerin, DC-SIGN, and DC-LAMP were absent. This indicates that the here generated CD14(dim/-) VC can not be considered as classical LC/DC. It was also impossible to turn the CD14(dim/-) mo-derived VC population into typical DC by culture for one week in GM-CSF/IL-4 or LPS. In fact the cells died tinder such circumstances, gaining some macrophage characteristics before dying. The IL-12 production from mo-derived CD14(dim/-) VC was lower, whereas the production of IL-10 was higher as compared to iDC. Consequently the T cells that were stimulated by these mo-derived VC produced less IFN-gamma as compared with T cells stimulated by iDC. Our data indicate that it is possible to rapidly generate a population of CD14(dim/-) veiled accessory cells from monocytes. The marker pattern and cytokine production of these VC indicate that this population is not a classical DC population. The cells might earlier be related to the veiled macrophage-like cells also earlier described in afferent lymph.

Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation.

PubMed

Lee, Joonsup; Wen, Beryl; Carter, Elizabeth A; Combes, Valery; Grau, Georges E R; Lay, Peter A

2017-07-01

Microvesicles (MVs) are involved in cell-cell interactions, including disease pathogenesis. Nondestructive Fourier-transform infrared (FTIR) spectra from MVs were assessed as a technique to provide new biochemical insights into a LPS-induced monocyte model of septic shock. FTIR spectroscopy provided a quick method to investigate relative differences in biomolecular content of different MV populations that was complementary to traditional semiquantitative omics approaches, with which it is difficult to provide information on relative changes between classes (proteins, lipids, nucleic acids, carbohydrates) or protein conformations. Time-dependent changes were detected in biomolecular contents of MVs and in the monocytes from which they were released. Differences in phosphatidylcholine and phosphatidylserine contents were observed in MVs released under stimulation, and higher relative concentrations of RNA and α-helical structured proteins were present in stimulated MVs compared with MVs from resting cells. FTIR spectra of stimulated monocytes displayed changes that were consistent with those observed in the corresponding MVs they released. LPS-stimulated monocytes had reduced concentrations of nucleic acids, α-helical structured proteins, and phosphatidylcholine compared with resting monocytes but had an increase in total lipids. FTIR spectra of MV biomolecular content will be important in shedding new light on the mechanisms of MVs and the different roles they play in physiology and disease pathogenesis.-Lee, J., Wen, B., Carter, E. A., Combes, V., Grau, G. E. R., Lay, P. A. Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation. © FASEB.

HCV-induced miR146a controls SOCS1/STAT3 and cytokine expression in monocytes to promote regulatory T cell development

PubMed Central

Ren, Jun P; Ying, Rue S; Cheng, Yong Q.; Wang, Ling; Elgazzar, Mohamed A.; Li, Guang Y.; Ning, Shun B.; Moorman, Jonathan P.; Yao, Zhi Q.

2016-01-01

Host innate and adaptive immune responses must be tightly regulated by an intricate balance between positive and negative signals to ensure their appropriate onset and termination while fighting pathogens and avoiding autoimmunity; persistent pathogens may usurp these regulatory machineries to dampen host immune responses for their persistence in vivo. Here we demonstrate that miR146a is up-regulated in monocytes from hepatitis C virus (HCV)-infected individuals compared to control subjects. Interestingly, miR146a expression in monocytes without HCV infection increased, whereas its level in monocytes with HCV infection decreased, following Toll-like receptor (TLR) stimulation. This miR146a induction by HCV infection and differential response to TLR stimulation were recapitulated in vitro in monocytes co-cultured with hepatocytes with or without HCV infection. Importantly, inhibition of miR146a in monocytes from HCV-infected patients led to a decrease in IL-23, IL-10, and TGF-β expressions through induction of suppressor of cytokine signaling 1 (SOCS1) and inhibition of signal transducer and activator transcription 3 (STAT3), and this subsequently resulted in a decrease in regulatory T cells (Tregs) accumulated during HCV infection. These results suggest that miR146a may regulate SOCS1/STAT3 and cytokine signaling in monocytes, directing T cell differentiation and balancing immune clearance and immune injury during chronic viral infection. PMID:27004559

Glucocorticoid dexamethasone down-regulates basal and vitamin D3 induced cathelicidin expression in human monocytes and bronchial epithelial cell line.

PubMed

Kulkarni, Nikhil Nitin; Gunnarsson, Hörður Ingi; Yi, Zhiqian; Gudmundsdottir, Steinunn; Sigurjonsson, Olafur E; Agerberth, Birgitta; Gudmundsson, Gudmundur H

2016-02-01

Glucocorticoids (GCs) have been extensively used as the mainstream treatment for chronic inflammatory disorders. The persistent use of steroids in the past decades and the association with secondary infections warrants for detailed investigation into their effects on the innate immune system and the therapeutic outcome. In this study, we analyse the effect of GCs on antimicrobial polypeptide (AMP) expression. We hypothesize that GC related side effects, including secondary infections are a result of compromised innate immune responses. Here, we show that treatment with dexamethasone (Dex) inhibits basal mRNA expression of the following AMPs; human cathelicidin, human beta defensin 1, lysozyme and secretory leukocyte peptidase 1 in the THP-1 monocytic cell-line (THP-1 monocytes). Furthermore, pre-treatment with Dex inhibits vitamin D3 induced cathelicidin expression in THP-1 monocytes, primary monocytes and in the human bronchial epithelial cell line BCi NS 1.1. We also demonstrate that treatment with the glucocorticoid receptor (GR) inhibitor RU486 counteracts Dex mediated down-regulation of basal and vitamin D3 induced cathelicidin expression in THP-1 monocytes. Moreover, we confirmed the anti-inflammatory effect of Dex. Pre-treatment with Dex inhibits dsRNA mimic poly IC induction of the inflammatory chemokine IP10 (CXCL10) and cytokine IL1B mRNA expression in THP-1 monocytes. These results suggest that GCs inhibit innate immune responses, in addition to exerting beneficial anti-inflammatory effects. Copyright © 2015 Elsevier GmbH. All rights reserved.

Sphingosine 1-phosphate receptor 3 regulates recruitment of anti-inflammatory monocytes to microvessels during implant arteriogenesis

PubMed Central

Awojoodu, Anthony O.; Ogle, Molly E.; Sefcik, Lauren S.; Bowers, Daniel T.; Martin, Kyle; Brayman, Kenneth L.; Lynch, Kevin R.; Peirce-Cottler, Shayn M.; Botchwey, Edward

2013-01-01

Endothelial cells play significant roles in conditioning tissues after injury by the production and secretion of angiocrine factors. At least two distinct subsets of monocytes, CD45+CD11b+Gr1+Ly6C+ inflammatory and CD45+CD11b+Gr1−Ly6C− anti-inflammatory monocytes, respond differentially to these angiocrine factors and promote pathogen/debris clearance and arteriogenesis/tissue regeneration, respectively. We demonstrate here that local sphingosine 1-phosphate receptor 3 (S1P3) agonism recruits anti-inflammatory monocytes to remodeling vessels. Poly(lactic-co-glycolic acid) thin films were used to deliver FTY720, an S1P1/3 agonist, to inflamed and ischemic tissues, which resulted in a reduction in proinflammatory cytokine secretion and an increase in regenerative cytokine secretion. The altered balance of cytokine secretion results in preferential recruitment of anti-inflammatory monocytes from circulation. The chemotaxis of these cells, which express more S1P3 than inflammatory monocytes, toward SDF-1α was also enhanced with FTY720 treatment, but not in S1P3 knockout cells. FTY720 delivery enhanced arteriolar diameter expansion and increased length density of the local vasculature. This work establishes a role for S1P receptor signaling in the local conditioning of tissues by angiocrine factors that preferentially recruit regenerative monocytes that can enhance healing outcomes, tissue regeneration, and biomaterial implant functionality. PMID:23918395

Fc receptors for mouse IgG1 on human monocytes: polymorphism and role in antibody-induced T cell proliferation.

PubMed

Tax, W J; Hermes, F F; Willems, R W; Capel, P J; Koene, R A

1984-09-01

In previous studies, it was shown that there is polymorphism in the mitogenic effect of mouse IgG1 monoclonal antibodies against the T3 antigen of human T cells. This polymorphism implies that IgG1 anti-T3 antibodies are not mitogenic for T cells from 30% of healthy individuals. The present results demonstrate that this polymorphism is caused by polymorphism of an Fc receptor for mouse IgG1, present on human monocytes. The Fc receptor for murine IgG1 could be detected by a newly developed rosetting assay on monocytes from all individuals responsive to the mitogenic effect of IgG1 anti-T3 antibodies. This Fc receptor was not detectable on monocytes from those individuals exhibiting no mitogenic responses to IgG1 anti-T3 monoclonal antibodies. Cross-linking of T3 antigens appears to be essential for antibody-induced mitosis of T cells, because mononuclear cells that did not proliferate in response to WT 31 (an IgG1 antibody against T3 antigen) showed a proliferative response to Sepharose beads coated with WT 31. The Fc receptor--if functionally present--may be involved in the cross-linking of T3 antigens through anti-T3 antibodies. Further evidence for the involvement of this Fc receptor in antibody-induced T cell proliferation was provided by inhibition studies. Immune complexes containing IgG1 antibodies were able to inhibit the proliferative response to IgG1 anti-T3 antibodies. This inhibition by immune complexes appears to be mediated through the monocyte Fc receptor for mouse IgG1. These findings are important for the interpretation of previously described inhibitory effects of anti-T cell monoclonal antibodies on T cell proliferation, and show that such inhibitory effects may be monocyte-mediated (via immune complexes) rather than caused by a direct involvement of the respective T cell antigens in T cell mitosis. The Fc receptor for mouse IgG1 plays a role in antibody-induced T cell proliferation. Its polymorphism may have important implications for the therapeutic use of IgG1 monoclonal antibodies.

Impact of brief exercise on circulating monocyte gene and microRNA expression: implications for atherosclerotic vascular disease

PubMed Central

Radom-Aizik, Shlomit; Zaldivar, Frank P.; Haddad, Fadia; Cooper, Dan M.

2014-01-01

Physical activity can prevent and/or attenuate atherosclerosis, a disease clearly linked to inflammation. Paradoxically, even brief exercise induces a stress response and increases inflammatory cells like monocytes in the circulation. We hypothesized that exercise would regulate the expression of genes, gene pathways, and microRNAs in monocytes in a way that could limit pro-inflammatory function and drive monocytes to prevent, rather than contribute to, atherosclerosis. Twelve healthy men (22-30 yr old) performed ten 2-min bouts of cycle ergometer exercise at a constant work equivalent to an average of 82% of maximum O2 consumption interspersed with 1-min rest. Blood was drawn before and immediately after the exercise. Monocytes were isolated from peripheral blood mononuclear cells. Flow cytometry was used to identify monocyte subtypes. We used Affymetrix U133+2.0 arrays for gene expression and Agilent Human miRNA V2 Microarray for miRNAs. A stringent statistical approach (FDR < 0.05) was used to determine that exercise significantly altered the expression of 894 annotated genes and 19 miRNAs. We found distinct gene alterations that were likely to direct monocytes in an anti-inflammatory, anti-atherogenic pathway, including the downregulation of monocyte TNF, TLR4, and CD36 genes and the upregulation of EREG and CXCR4. Exercise significantly altered a number of microRNAs that likely influence monocytes involvement in vascular health. Exercise leads to a novel genomic profile of circulating monocytes, which appears to promote cardiovascular health despite the overall stress response. PMID:24423463

Update on the pathogenesis of Scleroderma: focus on circulating progenitor cells.

PubMed

Brunasso, Alexandra Maria Giovanna; Massone, Cesare

2016-01-01

In systemic sclerosis (SSc), the development of fibrosis seems to be a consequence of the initial ischemic process related to an endothelial injury. The initial trigger event in SSc is still unknown, but circulating progenitor cells (CPCs) might play a key role. Such cells have the ability to traffic into injury sites, exhibiting inflammatory features of macrophages, tissue remodeling properties of fibroblasts, and vasculogenesis functions of endothelial cells. The different subsets of CPCs described thus far in SSc arise from a pool of circulating monocyte precursors (CD14 (+) cells) and probably correspond to a different degree of differentiation of a single cell of origin. Several subsets of CPCs have been described in patients with SSc, all have a monocytic origin but may or may not express CD14, and all of these cells have the ability to give origin to endothelial cells, or collagen (Col)-producing cells, or both. We were able to identify six subsets of CPCs: pluripotent stem cells (CD14 (+), CD45 (+), and CD34 (+)), monocyte-derived multipotential cells (MOMCs) or monocyte-derived mesenchymal progenitors (CD14 (+), CD45 (+), CD34 (+), Col I (+), CD11b (+), CD68 (+), CD105 (+), and VEGFR1 (+)), early endothelial progenitor cells (EPCs) or monocytic pro-angiogenic hematopoietic cells or circulating hematopoietic cells (CD14 (+), CD45 (+), CD34 (low/-), VEGFR2 (+/-), CXCR4 (+), c-kit (+), and DC117 (+)), late EPCs (CD14 (-), CD133 (+), VEGFR2 (+), CD144 (+) [VE-cadherin (+)], and CD146 (+)), fibroblast-like cells (FLCs)/circulating Col-producing monocytes (CD14 (+), CD45 (+), CD34 (+/-), and Col I (+)), and fibrocytes (CD14 (-), CD45 (+), CD34 (+), Col I (+), and CXCR4 (+)). It has been demonstrated that circulating CD14 (+) monocytes with an activated phenotype are increased in patients with SSc when compared with normal subjects. CD14 (+), CD34 (+), and Col I (+) spindle-shaped cells have been found in increased numbers in lungs of SSc patients with interstitial lung disease. Elevated blood amounts of early EPCs have been found in patients with SSc by different groups of researchers and such levels correlate directly with the interstitial lung involvement. The prevalence of hematopoietic markers expressed by CPCs that migrate from blood into injury sites in SSc differs and changes according to the degree of differentiation. CXCR4 is the most commonly expressed marker, followed by CD34 and CD45 at an end stage of differentiation. Such difference also indicates a continuous process of cell differentiation that might relate to the SSc clinical phenotype (degree of fibrosis and vascular involvement). A deeper understanding of the role of each subtype of CPCs in the development of the disease will help us to better classify patients in order to offer them targeted approaches in the future.

ACTIVATED NEUTROPHILS INHIBIT PHAGOCYTOSIS BY HUMAN MONOCYTE CELLS IN VITRO

EPA Science Inventory

We have previously reported the correlation of decreased phagocytosis of opsonized zymosan by sputum monocytic cells with the increase in sputum neutrophils in volunteers 6h after inhalation of endotoxin (20,000 EU) (Alexis, et al. JACI, 2003;112:353). To define whether an intrin...

In vitro immunotoxicity assessment of culture-derived extracellular vesicles in human monocytes

PubMed Central

Rosas, Lucia E.; Elgamal, Ola A.; Mo, Xiaokui; Phelps, Mitch A.; Schmittgen, Thomas D.; Papenfuss, Tracey L.

2016-01-01

The potential to engineer extracellular vesicles (EV) that target specific cells and deliver a therapeutic payload has propelled a growing interest in their development as promising therapeutics. These EV are often produced from cultured cells. Very little is known about the interaction of cell culture-derived EV with cells of the immune system and their potential immunomodulatory effects. The present study evaluated potential immunotoxic effects of HEK293T-derived EV on the human monocytic cell lines THP-1 and U937. Incubation of cells with different doses of EV for 16–24 h was followed by assessment of cytotoxicity and cell function by flow cytometry. Changes in cell functionality were evaluated by the capacity of cells to phagocytize fluorescent microspheres. In addition, the internalization of labeled EV in THP-1 and U937 cells was evaluated. Exposure to EV did not affect the viability of THP-1 or U937 cells. Although lower doses of the EV increased phagocytic capacity in both cell lines, phagocytic efficiency of individual cells was not affected by EV exposure at any of the doses evaluated. This study also demonstrated that THP-1 and U937 monocytic cells are highly permissive to EV entry in a dose-response manner. These results suggest that, although HEK293T-derived EV are efficiently internalized by human monocytic cells, they do not exert a cytotoxic effect or alter phagocytic efficiency on the cell lines evaluated. PMID:27075513

Dexamethasone increases expression of 5-lipoxygenase and its activating protein in human monocytes and THP-1 cells.

PubMed

Riddick, C A; Ring, W L; Baker, J R; Hodulik, C R; Bigby, T D

1997-05-15

The aim of this study was to assess the effect of dexamethasone on 5-lipoxygenase pathway expression in human peripheral blood monocytes and the acute monocytic leukemia cell line, THP-1. Cells were conditioned over a period of days with dexamethasone, at concentrations relevant in vivo, to study the effect of the glucocorticoid on calcium-ionophore-stimulated 5-lipoxygenase product and arachidonic acid release. The effect of dexamethasone on levels of immunoreactive protein and steady-state messenger RNA encoding for 5-lipoxygenase and its activating protein (5-LAP) was also assessed. Dexamethasone increased the stimulated release of 5-lipoxygenase products from both monocytes and THP-1 cells in a dose-dependent fashion. The increase in product generation was not due to changes in the availability of arachidonic acid. However, immunoreactive protein and steady-state messenger RNA encoding for 5-lipoxygenase and 5-LAP were increased by conditioning with dexamethasone. There was no apparent effect of the glucocorticoid on LTA4-hydrolase-immunoreactive protein levels or specific activity. We conclude that dexamethasone increases 5-lipoxygenase pathway expression in both monocytes and in THP-1 cells. This effect is due, at least in part, to increases in immunoreactive protein and steady-state messenger RNA encoding for 5-lipoxygenase and 5-LAP. These results suggest a role for glucocorticoids in the regulation of 5-lipoxygenase pathway expression in mononuclear phagocytes.

Cellular and molecular identity of tumor-associated macrophages in glioblastoma

PubMed Central

Chen, Zhihong; Feng, Xi; Herting, Cameron J.; Garcia, Virginia Alvarez; Nie, Kai; Pong, Winnie W.; Rasmussen, Rikke; Dwivedi, Bhakti; Seby, Sandra; Wolf, Susanne A.; Gutmann, David H.; Hambardzumyan, Dolores

2017-01-01

In glioblastoma (GBM), tumor-associated macrophages (TAM) represent up to one half of the cells of the tumor mass, including both infiltrating macrophages and resident brain microglia. In an effort to delineate the temporal and spatial dynamics of TAM composition during gliomagenesis, we employed two genetically engineered mouse models where oncogenic drivers and fluorescent reporters were expressed coordinately under the control of the monocyte/microglia-selective Cx3cr1 or Ccr2 promoters, respectively. Using this approach, we demonstrated that CX3CR1LoCCR2Hi monocytes were recruited to the glioblastoma, where they transitioned to CX3CR1HiCCR2Lo macrophages and CX3CR1HiCCR2− microglia-like cells. Infiltrating macrophages/monocytes constituted ~85% of the total TAM population, with resident microglia accounting for the ~15% remaining. Bone marrow-derived infiltrating macrophages/monocytes were recruited to the tumor early during GBM initiation, where they localized preferentially to perivascular areas. In contrast, resident microglia were localized mainly to peritumoral regions. RNA-sequencing analyses revealed differential gene expression patterns unique to infiltrating and resident cells, suggesting unique functions for each TAM population. Notably, limiting monocyte infiltration via Ccl2 genetic ablation prolonged the survival of tumor-bearing mice. Our findings illuminate the unique composition and functions of infiltrating and resident myeloid cells in GBM, establishing a rationale to target infiltrating cells in this neoplasm. PMID:28235764

Interferon beta 2/B-cell stimulatory factor type 2 shares identity with monocyte-derived hepatocyte-stimulating factor and regulates the major acute phase protein response in liver cells.

PubMed Central

Gauldie, J; Richards, C; Harnish, D; Lansdorp, P; Baumann, H

1987-01-01

One of the oldest and most preserved of the homeostatic responses of the body to injury is the acute phase protein response associated with inflammation. The liver responds to hormone-like mediators by the increased synthesis of a series of plasma proteins called acute phase reactants. In these studies, we examined the relationship of hepatocyte-stimulating factor derived from peripheral blood monocytes to interferon beta 2 (IFN-beta 2), which has been cloned. Antibodies raised against fibroblast-derived IFN-beta having neutralizing activity against both IFN-beta 1 and -beta 2 inhibited the major hepatocyte-stimulating activity derived from monocytes. Fibroblast-derived mediator elicited the identical stimulated response in human HepG2 cells and primary rat hepatocytes as the monocyte cytokine. Finally, recombinant-derived human B-cell stimulatory factor type 2 (IFN-beta 2) from Escherichia coli induced the synthesis of all major acute phase proteins studied in human hepatoma HepG2 and primary rat hepatocyte cultures. These data demonstrate that monocyte-derived hepatocyte-stimulating factor and IFN-beta 2 share immunological and functional identity and that IFN-beta 2, also known as B-cell stimulatory factor and hybridoma plasmacytoma growth factor, has the hepatocyte as a major physiologic target and thereby is essential in controlling the hepatic acute phase response. Images PMID:2444978

The phenotype and function of preterm infant monocytes: implications for susceptibility to infection.

PubMed

de Jong, Emma; Strunk, Tobias; Burgner, David; Lavoie, Pascal M; Currie, Andrew

2017-09-01

The extreme vulnerability of preterm infants to invasive microbial infections has been attributed to "immature" innate immune defenses. Monocytes are important innate immune sentinel cells critical in the defense against infection in blood. They achieve this via diverse mechanisms that include pathogen recognition receptor- and inflammasome-mediated detection of microbes, migration into infected tissues, and differentiation into Mϕs and dendritic cells, initiation of the inflammatory cascade by free radicals and cytokine/chemokine production, pathogen clearance by phagocytosis and intracellular killing, and the removal of apoptotic cells. Relatively little is known about these cells in preterm infants, especially about how their phenotype adapts to changes in the microbial environment during the immediate postnatal period. Overall, preterm monocytes exhibit attenuated proinflammatory cytokine responses following stimulation by whole bacterial or specific microbial components in vitro. These attenuated cytokine responses cannot be explained by a lack of intracellular signaling events downstream of pattern recognition receptors. This hyporesponsiveness also contrasts with mature, term-like phagocytosis capabilities detectable even in the most premature infant. Finally, human data on the effects of fetal chorioamnionitis on monocyte biology are incomplete and inconsistent. In this review, we present an integrated view of human studies focused on monocyte functions in preterm infants. We discuss how a developmental immaturity of these cells may contribute to preterm infants' susceptibility to infections. © Society for Leukocyte Biology.

Modulating inflammatory monocytes with a unique microRNA gene signature ameliorates murine ALS.

PubMed

Butovsky, Oleg; Siddiqui, Shafiuddin; Gabriely, Galina; Lanser, Amanda J; Dake, Ben; Murugaiyan, Gopal; Doykan, Camille E; Wu, Pauline M; Gali, Reddy R; Iyer, Lakshmanan K; Lawson, Robert; Berry, James; Krichevsky, Anna M; Cudkowicz, Merit E; Weiner, Howard L

2012-09-01

Amyotrophic lateral sclerosis (ALS) is a progressive disease associated with neuronal cell death that is thought to involve aberrant immune responses. Here we investigated the role of innate immunity in a mouse model of ALS. We found that inflammatory monocytes were activated and that their progressive recruitment to the spinal cord, but not brain, correlated with neuronal loss. We also found a decrease in resident microglia in the spinal cord with disease progression. Prior to disease onset, splenic Ly6Chi monocytes expressed a polarized macrophage phenotype (M1 signature), which included increased levels of chemokine receptor CCR2. As disease onset neared, microglia expressed increased CCL2 and other chemotaxis-associated molecules, which led to the recruitment of monocytes to the CNS by spinal cord-derived microglia. Treatment with anti-Ly6C mAb modulated the Ly6Chi monocyte cytokine profile, reduced monocyte recruitment to the spinal cord, diminished neuronal loss, and extended survival. In humans with ALS, the analogous monocytes (CD14+CD16-) exhibited an ALS-specific microRNA inflammatory signature similar to that observed in the ALS mouse model, linking the animal model and the human disease. Thus, the profile of monocytes in ALS patients may serve as a biomarker for disease stage or progression. Our results suggest that recruitment of inflammatory monocytes plays an important role in disease progression and that modulation of these cells is a potential therapeutic approach.

CCR2-dependent Gr1high monocytes promote kidney injury in shiga toxin-induced hemolytic uremic syndrome in mice.

PubMed

Pohl, Judith-Mira; Volke, Julia K; Thiebes, Stephanie; Brenzel, Alexandra; Fuchs, Kerstin; Beziere, Nicolas; Ehrlichmann, Walter; Pichler, Bernd J; Squire, Anthony; Gueler, Faikah; Engel, Daniel R

2018-06-01

The hemolytic uremic syndrome (HUS) is a life-threatening disease of the kidney that is induced by shiga toxin-producing E.coli. Major changes in the monocytic compartment and in CCR2-binding chemokines have been observed. However, the specific contribution of CCR2-dependent Gr1 high monocytes is unknown. To investigate the impact of these monocytes during HUS, we injected a combination of LPS and shiga toxin into mice. We observed an impaired kidney function and elevated levels of the CCR2-binding chemokine CCL2 after shiga toxin/LPS- injection, thus suggesting Gr1 high monocyte infiltration into the kidney. Indeed, the number of Gr1 high monocytes was strongly increased one day after HUS induction. Moreover, these cells expressed high levels of CD11b suggesting activation after tissue entry. Non-invasive PET-MR imaging revealed kidney injury mainly in the kidney cortex and this damage coincided with the detection of Gr1 high monocytes. Lack of Gr1 high monocytes in Ccr2-deficient animals reduced neutrophil gelatinase-associated lipocalin and blood urea nitrogen levels. Moreover, the survival of Ccr2-deficient animals was significantly improved. Conclusively, this study demonstrates that CCR2-dependent Gr1 high monocytes contribute to the kidney injury during HUS and targeting these cells is beneficial during this disease. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tumour-cytolytic human monocyte-derived macrophages: a simple and efficient method for the generation and long-term cultivation as non-adherent cells in a serum-free medium.

PubMed

Streck, R J; Hurley, E L; Epstein, D A; Pauly, J L

1992-01-01

We report a simple and efficient culture procedure for the generation of tumour-cytolytic human monocyte-derived macrophages (MAC). In this method, normal human peripheral blood mononuclear cells, isolated using a conventional Ficoll-Hypaque density gradient procedure, are cultured as a heterogenous leukocyte population in Teflon or other hydrophobic cultureware, in a commercially available serum-free culture medium (M-SFM) that has been formulated specifically for the cultivation and ex vivo stimulation of human monocytes and MAC, and in the absence of exogenous mitogens, antigens, cytokines or other stimulants. This procedure features a negative-selection technique that takes advantage of the differential survival of blood leukocytes. Using the prescribed in vitro conditions, lymphocytes survived relatively poorly, whereas monocytes differentiated in the absence of exogenous stimulants into mature tumour-cytolytic MAC. The MAC were present as non-adherent, single cells that expressed good viability (greater than 95%) for a prolonged period (greater than 60 days). When compared to conventional procedures for generating MAC, the prescribed technique is thought to offer several important advantages in that it: (a) eliminates the tedious and cumbersome monocyte isolation procedures, thus providing a significant savings not only in time and money but also in eliminating repetitive cell manipulations that have often been associated with damage to monocyte morphology and/or function; (b) reduces the loss of monocyte subsets that are not recovered during specific isolation procedures; (c) facilitates harvesting a single cell, non-adherent suspension of immunocompetent MAC suitable for various examinations including analyses defining MAC morphology, cytochemistry, phenotype and function; and (d) eliminates variability and artifacts associated with different sera that are utilised frequently as medium supplements. The utility of the prescribed method is illustrated by the results of ongoing studies in which scanning electron microscopy and confocal laser scanning microscopy are being used to define MAC function in different immunological reactions, and examples of these observations are presented herein.

MicroRNA-Mediated Down-Regulation of M-CSF Receptor Contributes to Maturation of Mouse Monocyte-Derived Dendritic Cells

PubMed Central

Riepsaame, Joey; van Oudenaren, Adri; den Broeder, Berlinda J. H.; van IJcken, Wilfred F. J.; Pothof, Joris; Leenen, Pieter J. M.

2013-01-01

Dendritic cell (DC) maturation is a tightly regulated process that requires coordinated and timed developmental cues. Here we investigate whether microRNAs are involved in this process. We identify microRNAs in mouse GM-CSF-generated, monocyte-related DC (GM-DC) that are differentially expressed during both spontaneous and LPS-induced maturation and characterize M-CSF receptor (M-CSFR), encoded by the Csf1r gene, as a key target for microRNA-mediated regulation in the final step toward mature DC. MicroRNA-22, -34a, and -155 are up-regulated in mature MHCIIhi CD86hi DC and mediate Csf1r mRNA and protein down-regulation. Experimental inhibition of Csf1r-targeting microRNAs in vitro results not only in sustained high level M-CSFR protein expression but also in impaired DC maturation upon stimulation by LPS. Accordingly, over-expression of Csf1r in GM-DC inhibits terminal differentiation. Taken together, these results show that developmentally regulated microRNAs control Csf1r expression, supplementing previously identified mechanisms that regulate its transcription and protein surface expression. Furthermore, our data indicate a novel function for Csf1r in mouse monocyte-derived DC, showing that down-regulation of M-CSFR expression is essential for final DC maturation. PMID:24198819

Glucocorticoid-induced TNF receptor family-related protein ligand regulates the migration of monocytes to the inflamed intestine

PubMed Central

Liao, Gongxian; van Driel, Boaz; Magelky, Erica; O'Keeffe, Michael S.; de Waal Malefyt, Rene; Engel, Pablo; Herzog, Roland W.; Mizoguchi, Emiko; Bhan, Atul K.; Terhorst, Cox

2014-01-01

Glucocorticoid-induced TNF receptor family-related protein (GITR) regulates the function of both T cells and antigen-presenting cells (APCs), while the function of GITR ligand (GITR-L) is largely unknown. Here we evaluate the role of GITR-L, whose expression is restricted to APCs, in the development of enterocolitis. On injecting naive CD4+ T cells, GITR-L−/−Rag−/− mice develop a markedly milder colitis than Rag−/− mice, which correlates with a 50% reduction of Ly6C+CD11b+MHCII+ macrophages in the lamina propria and mesenteric lymph nodes. The same result was observed in αCD40-induced acute colitis and during peritonitis, suggesting an altered monocyte migration. In line with these observations, the number of nondifferentiated monocytes was approximately 3-fold higher in the spleen of GITR-L−/−Rag−/− mice than in Rag−/− mice after αCD40 induction. Consistent with the dynamic change in the formation of an active angiotensin II type 1 receptor (AT1) dimer in GITR-L−/− splenic monocytes during intestinal inflammation, the migratory capability of splenic monocytes from GITR-L-deficient mice was impaired in an in vitro transwell migration assay. Conversely, αGITR-L reduces the number of splenic Ly6Chi monocytes, concomitantly with an increase in AT1 dimers. We conclude that GITR-L regulates the number of proinflammatory macrophages in sites of inflammation by controlling the egress of monocytes from the splenic reservoir.—Liao, G., van Driel, B., Magelky, E., O'Keeffe, M. S., de Waal Malefyt, R., Engel, P., Herzog, R. W., Mizoguchi, E., Bhan, A. K., Terhorst, C. Glucocorticoid-induced TNF receptor family-related protein ligand regulates the migration of monocytes to the inflamed intestine. PMID:24107315

Monocyte-endothelial adhesion in chronic rheumatoid arthritis. In situ detection of selectin and integrin-dependent interactions.

PubMed Central

Grober, J S; Bowen, B L; Ebling, H; Athey, B; Thompson, C B; Fox, D A; Stoolman, L M

1993-01-01

Blood monocytes are the principal reservoir for tissue macrophages in rheumatoid synovitis. Receptor-mediated adhesive interactions between circulating cells and the synovial venules initiate recruitment. These interactions have been studied primarily in cultured endothelial cells. Thus the functional activities of specific adhesion receptors, such as the endothelial selectins and the leukocytic integrins, have not been evaluated directly in diseased tissues. We therefore examined monocyte-microvascular interactions in rheumatoid synovitis by modifying the Stamper-Woodruff frozen section binding assay initially developed to study lymphocyte homing. Specific binding of monocytes to venules lined by low or high endothelium occurred at concentrations as low as 5 x 10(5) cells/ml. mAbs specific for P-selectin (CD62, GMP-140/PADGEM) blocked adhesion by > 90% in all synovitis specimens examined. In contrast, P-selectin-mediated adhesion to the microvasculature was either lower or absent in frozen sections of normal foreskin and placenta. mAbs specific for E-selectin (ELAM-1) blocked 20-50% of monocyte attachment in several RA synovial specimens but had no effect in others. mAbs specific for LFA-1, Mo1/Mac 1, the integrin beta 2-chain, and L-selectin individually inhibited 30-40% of adhesion. An mAb specific for the integrin beta 1-chain inhibited the attachment of elutriated monocytes up to 20%. We conclude that P-selectin associated with the synovial microvasculature initiates shear-resistant adhesion of monocytes in the Stamper-Woodruff assay and stabilizes bonds formed by other selectins and the integrins. Thus the frozen section binding assay permits direct evaluation of leukocyte-microvascular adhesive interactions in inflamed tissues and suggests a prominent role for P-selectin in monocyte recruitment in vivo. Images PMID:7685772

Differential Activation of Human Monocytes and Lymphocytes by Distinct Strains of Trypanosoma cruzi.

PubMed

Magalhães, Luísa M D; Viana, Agostinho; Chiari, Egler; Galvão, Lúcia M C; Gollob, Kenneth J; Dutra, Walderez O

2015-01-01

Trypanosoma cruzi strains are currently classified into six discrete typing units (DTUs) named TcI to VI. It is known that these DTUs have different geographical distribution, as well as biological features. TcI and TcII are major DTUs found in patients from northern and southern Latin America, respectively. Our hypothesis is that upon infection of human peripheral blood cells, Y strain (Tc II) and Col cl1.7 (Tc I), cause distinct immunological changes, which might influence the clinical course of Chagas disease. We evaluated the infectivity of CFSE-stained trypomastigotes of Col cl1.7 and Y strain in human monocytes for 15 and 72 hours, and determined the immunological profile of lymphocytes and monocytes exposed to the different isolates using multiparameter flow cytometry. Our results showed a similar percentage and intensity of monocyte infection by Y and Col cl1.7. We also observed an increased expression of CD80 and CD86 by monocytes infected with Col cl1.7, but not Y strain. IL-10 was significantly higher in monocytes infected with Col cl1.7, as compared to Y strain. Moreover, infection with Col cl1.7, but not Y strain, led to an increased expression of IL-17 by CD8+ T cells. On the other hand, we observed a positive correlation between the expression of TNF-alpha and granzyme A only after infection with Y strain. Our study shows that while Col cl1.7 induces higher monocyte activation and, at the same time, production of IL-10, infection with Y strain leads to a lower monocyte activation but higher inflammatory profile. These results show that TcI and TcII have a distinct immunological impact on human cells during early infection, which might influence disease progression.

The cellular lesion of humoral rejection: predominant recruitment of monocytes to peritubular and glomerular capillaries.

PubMed

Fahim, T; Böhmig, G A; Exner, M; Huttary, N; Kerschner, H; Kandutsch, S; Kerjaschki, D; Bramböck, A; Nagy-Bojarszky, K; Regele, H

2007-02-01

Accumulation of inflammatory cells within capillaries is a common morphologic feature of humoral renal allograft rejection and is most easily appreciated if it occurs in glomeruli. The aim of our study was to determine the amount and composition of immune cells within glomeruli and peritubular capillaries (PTC) in cellular and humoral allograft rejection. Immunofluorescent double-labeling for CD31 and CD3 or CD68 was used for phenotyping and enumerating immune cells within glomeruli and PTC. The major findings are: (1) accumulation of immune cells in PTC is far more common than it would be anticipated based on the assessment by conventional histology; (2) it is not the absolute number of immune cells accumulating within capillaries, but rather the composition of the intracapillary cell population that distinguishes humoral rejection from cellular rejection and (3) in C4d positive biopsies a predominantly monocytic cell population accumulates not only within glomeruli but also within PTC. The median value of monocyte/T-cell ratio within PTC was 2.3 in C4d positive biopsies but only 1 (p = 0.0008) in C4d negative biopsies. Given their prominent presence within capillaries and their extensive biological versatility monocytes might contribute to the capillary damage observed in acute and chronic allograft rejection.

Regulation of B7.1 costimulatory molecule is mediated by the IFN regulatory factor-7 through the activation of JNK in lipopolysaccharide-stimulated human monocytic cells.

PubMed

Lim, Wilfred; Gee, Katrina; Mishra, Sasmita; Kumar, Ashok

2005-11-01

The engagement of CD28 or CTLA-4 with B7.1 provides the essential second costimulatory signal that regulates the development of immune responses, including T cell activation, differentiation, and induction of peripheral tolerance. The signaling molecules and the transcription factors involved in B7.1 regulation are poorly understood. In this study we investigated the role of MAPKs in the regulation of LPS-induced B7.1 expression in human monocytes and the promonocytic THP-1 cells. Our results show that LPS-induced B7.1 expression in monocytic cells did not involve the activation of either p38 or ERKs. Using the JNK-specific inhibitor SP600125, small interfering RNAs specific for JNK1 and JNK2, and agents such as dexamethasone that inhibit JNK activation, we determined that LPS-induced B7.1 expression was regulated by JNK MAPK in both monocytes and THP-1 cells. In addition, we identified a distinct B7.1-responsive element corresponding to the IFN regulatory factor-7 (IRF-7) binding site in the B7.1 promoter responsible for the regulation of LPS-induced B7.1 transcription. Furthermore, SP600125 and dexamethasone inhibited LPS-induced IRF-7 activity. Taken together, these results suggest that LPS-induced B7.1 transcription in human monocytic cells may be regulated by JNK-mediated activation of the IRF-7 transcription factor.

Dexamethasone attenuates oxidation of extracellular matrix proteins by human monocytes.

PubMed

Ahmed, Shahid; Adamidis, Ananea; Jan, Louis C; Gibbons, Nora; Mattana, Joseph

2003-10-01

In response to infection or in immune complex-mediated diseases, inflammatory cells may oxidatively damage extracellular matrix (ECM) proteins. In this study we evaluated whether human monocytes could oxidize ECM and whether this could be modulated by exposure to LPS, IgG complexes, and dexamethasone (DEX). Wells in tissue culture plates were coated with the ECM preparation Matrigel. Porous inserts with or without the human monocyte cell line THP-1 were placed into ECM-containing wells and cells were exposed to control conditions or to LPS (10 ng/ml), IgG complexes (200 and 500 microg/ml), or DEX (10(-7) and 10(-6) M). ECM was then subjected to Western blot analysis using an antibody to oxidized protein. In addition, Western blot analysis was carried out on DEX-treated cells to evaluate expression of the NADPH oxidase components p67-phox and gp91-phox. THP-1 cells enhanced ECM oxidation and this effect was augmented by LPS and by IgG aggregates. Preincubation of cells with DEX attenuated ECM oxidation and was also associated with decreased expression of p67-phox and gp91-phox. These findings suggest that human monocytes can oxidize ECM proteins and that this may be modulated by IgG complexes and LPS. Dexamethasone appears to attenuate ECM oxidation and a better understanding of this mechanism might allow for interventions to minimize oxidative damage to ECM proteins by monocytes in infectious and inflammatory states.

Protective properties of artichoke (Cynara scolymus) against oxidative stress induced in cultured endothelial cells and monocytes.

PubMed

Zapolska-Downar, Danuta; Zapolski-Downar, Andrzej; Naruszewicz, Marek; Siennicka, Aldona; Krasnodebska, Barbara; Kołdziej, Blanka

2002-11-01

It is currently believed that oxidative stress and inflammation play a significant role in atherogenesis. Artichoke extract exhibits hypolipemic properties and contains numerous active substances with antioxidant properties in vitro. We have studied the influence of aqueous and ethanolic extracts from artichoke on intracellular oxidative stress stimulated by inflammatory mediators (TNFalpha and LPS) and ox-LDL in endothelial cells and monocytes. Oxidative stress which reflects the intracellular production of reactive oxygen species (ROS) was followed by measuring the oxidation of 2', 7'-dichlorofluorescin (DCFH) to 2', 7'-dichlorofluorescein (DCF). Agueous and ethanolic extracts from artichoke were found to inhibit basal and stimulated ROS production in endothelial cells and monocytes in dose dependent manner. In endothelial cells, the ethanolic extract (50 microg/ml) reduced ox-LDL-induced intracellular ROS production by 60% (p<0,001) while aqueous extract (50 microg/ml) by 43% (p<0,01). The ethanolic extract (50 microg/ml) reduced ox-LDL-induced intracellular ROS production in monocytes by 76% (p<0,01). Effective concentrations (25-100 microg/ml) were well below the cytotoxic levels of the extracts which started at 1 mg/ml as assessed by LDH leakage and trypan blue exclusion. Penetration of some active substances into the cells was necessary for inhibition to take place as juged from the effect of preincubation time. These results demonstrate that artichoke extracts have marked protective properties against oxidative stress induced by inflammatory mediators and ox-LDL in cultured endothelial cells and monocytes.

Monosodium Urate Crystals Induce Upregulation of NK1.1-Dependent Killing by Macrophages and Support Tumor-Resident NK1.1+ Monocyte/Macrophage Populations in Antitumor Therapy.

PubMed

Steiger, Stefanie; Kuhn, Sabine; Ronchese, Franca; Harper, Jacquie L

2015-12-01

Macrophages display phenotypic and functional heterogeneity dependent on the changing inflammatory microenvironment. Under some conditions, macrophages can acquire effector functions commonly associated with NK cells. In the current study, we investigated how the endogenous danger signal monosodium urate (MSU) crystals can alter macrophage functions. We report that naive, primary peritoneal macrophages rapidly upregulate the expression of the NK cell-surface marker NK1.1 in response to MSU crystals but not in response to LPS or other urate crystals. NK1.1 upregulation by macrophages was associated with mechanisms including phagocytosis of crystals, NLRP3 inflammasome activation, and autocrine proinflammatory cytokine signaling. Further analysis demonstrated that MSU crystal-activated macrophages exhibited NK cell-like cytotoxic activity against target cells in a perforin/granzyme B-dependent manner. Furthermore, analysis of tumor hemopoietic cell populations showed that effective, MSU-mediated antitumor activity required coadministration with Mycobacterium smegmatis to induce IL-1β production and significant accumulation of monocytes and macrophages (but not granulocytes or dendritic cells) expressing elevated levels of NK1.1. Our findings provide evidence that MSU crystal-activated macrophages have the potential to develop tumoricidal NK cell-like functions that may be exploited to boost antitumor activity in vivo. Copyright © 2015 by The American Association of Immunologists, Inc.

Macrophage Responses to Epithelial Dysfunction Promote Lung Fibrosis in Aging

DTIC Science & Technology

2017-10-01

alveolar macrophages based on single cell molecular classification in patients with pulmonary fibrosis. We have recruited a planned number of patients...biomarkers expressed by human tissue-resident and monocyte-derived alveolar macrophages based on single cell molecular classification in patients with...identify novel biomarkers expressed by human tissue-resident and monocyte- derived alveolar macrophages based on single cell molecular classification

Phenotyping of peripheral blood mononuclear cells during acute dengue illness demonstrates infection and increased activation of monocytes in severe cases compared to classic dengue fever

PubMed Central

Durbin, Anna P.; Vargas, Maria José; Wanionek, Kimberli; Hammond, Samantha N.; Gordon, Aubree; Rocha, Crisanta; Balmaseda, Angel; Harris, Eva

2008-01-01

In vitro studies have attempted to identify dengue virus (DEN) target cells in peripheral blood; however, extensive phenotyping of peripheral blood mononuclear cells (PBMCs) from dengue patients has not been reported. PBMCs collected from hospitalized children suspected of acute dengue were analyzed for DEN prM, CD32, CD86, CD14, CD11c, CD16, CD209, CCR7, CD4, and CD8 by flow cytometry to detect DEN antigen in PBMCs and to phenotype DEN-positive cells. DEN prM was detected primarily in activated monocytes (CD14+, CD32+, CD86+, CD11c+). A subset of samples analyzed for DEN nonstructural protein 3 (NS3) confirmed that approximately half of DEN antigen-positive cells contained replicating virus. A higher percentage of PBMCs from DHF patients expressed prM, CD86, CD32, and CD11c than did those from DF patients. Increased activation of monocytes and greater numbers of DEN-infected cells were associated with more severe dengue, implicating a role for monocyte activation in dengue immunopathogenesis. PMID:18452966

A novel murine model of rhinoscleroma identifies Mikulicz cells, the disease signature, as IL-10 dependent derivatives of inflammatory monocytes

PubMed Central

Fevre, Cindy; Almeida, Ana S; Taront, Solenne; Pedron, Thierry; Huerre, Michel; Prevost, Marie-Christine; Kieusseian, Aurélie; Cumano, Ana; Brisse, Sylvain; Sansonetti, Philippe J; Tournebize, Régis

2013-01-01

Rhinoscleroma is a human specific chronic disease characterized by the formation of granuloma in the airways, caused by the bacterium Klebsiella pneumoniae subspecies rhinoscleromatis, a species very closely related to K. pneumoniae subspecies pneumoniae. It is characterized by the appearance of specific foamy macrophages called Mikulicz cells. However, very little is known about the pathophysiological processes underlying rhinoscleroma. Herein, we characterized a murine model recapitulating the formation of Mikulicz cells in lungs and identified them as atypical inflammatory monocytes specifically recruited from the bone marrow upon K. rhinoscleromatis infection in a CCR2-independent manner. While K. pneumoniae and K. rhinoscleromatis infections induced a classical inflammatory reaction, K. rhinoscleromatis infection was characterized by a strong production of IL-10 concomitant to the appearance of Mikulicz cells. Strikingly, in the absence of IL-10, very few Mikulicz cells were observed, confirming a crucial role of IL-10 in the establishment of a proper environment leading to the maturation of these atypical monocytes. This is the first characterization of the environment leading to Mikulicz cells maturation and their identification as inflammatory monocytes. PMID:23554169

TGF-β1-Induced Epithelial–Mesenchymal Transition Promotes Monocyte/Macrophage Properties in Breast Cancer Cells

PubMed Central

Johansson, Joel; Tabor, Vedrana; Wikell, Anna; Jalkanen, Sirpa; Fuxe, Jonas

2015-01-01

Breast cancer progression toward metastatic disease is linked to re-activation of epithelial–mesenchymal transition (EMT), a latent developmental process. Breast cancer cells undergoing EMT lose epithelial characteristics and gain the capacity to invade the surrounding tissue and migrate away from the primary tumor. However, less is known about the possible role of EMT in providing cancer cells with properties that allow them to traffic to distant sites. Given the fact that pro-metastatic cancer cells share a unique capacity with immune cells to traffic in-and-out of blood and lymphatic vessels we hypothesized that tumor cells undergoing EMT may acquire properties of immune cells. To study this, we performed gene-profiling analysis of mouse mammary EpRas tumor cells that had been allowed to adopt an EMT program after long-term treatment with TGF-β1 for 2 weeks. As expected, EMT cells acquired traits of mesenchymal cell differentiation and migration. However, in addition, we found another cluster of induced genes, which was specifically enriched in monocyte-derived macrophages, mast cells, and myeloid dendritic cells, but less in other types of immune cells. Further studies revealed that this monocyte/macrophage gene cluster was enriched in human breast cancer cell lines displaying an EMT or a Basal B profile, and in human breast tumors with EMT and undifferentiated (ER−/PR−) characteristics. The results identify an EMT-induced monocyte/macrophage gene cluster, which may play a role in breast cancer cell dissemination and metastasis. PMID:25674539

Human trophoblasts recruited T lymphocytes and monocytes into decidua by secretion of chemokine CXCL16 and interaction with CXCR6 in the first-trimester pregnancy.

PubMed

Huang, Yu; Zhu, Xiao-Yong; Du, Mei-Rong; Li, Da-Jin

2008-02-15

During human early pregnancy, fetus-derived trophoblasts come into direct contact with maternal immune cells at the maternofetal interface. At sites of placental attachment, invasive extravillous trophoblasts encounter decidual leukocytes (DLC) that accumulate within the decidua. Because we first found chemokine CXCL16 was highly expressed in and secreted by the first-trimester human trophoblasts previously, in this study we tested the hypothesis of whether the fetal trophoblasts can direct migration of maternal T lymphocyte and monocytes into decidua by secreting CXCL16. We analyzed the transcription and translation of CXCL16 in the isolated first-trimester human trophoblast, and examined the kinetic secretion of CXCL16 in the supernatant of the primary-cultured trophoblasts. We demonstrated that the sole receptor of CXCL16, CXCR6, is preferentially expressed in T lymphocytes, NKT cells, and monocytes, hardly expressed in two subsets of NK cells from either the peripheral blood or decidua. We further demonstrated the chemotactic activity of CXCL16 in the supernatant of the primary trophoblast on the peripheral mononuclear cells and DLC. Moreover, the CXCL16/CXCR6 interaction is involved in the migration of the peripheral T lymphocytes, gammadelta T cells, and monocytes, but not NKT cells. In addition, the trophoblast-conditioned medium could enrich PBMC subsets selectively to constitute a leukocyte population with similar composition to that of DLC, which suggests that the fetus-derived trophoblasts can attract T cells, gammadelta T cells, and monocytes by producing CXCL16 and interaction with CXCR6 on these cells, leading to forming a specialized immune milieu at the maternofetal interface.

Phenolic compounds alone or in combination may be involved in propolis effects on human monocytes.

PubMed

Cardoso, Eliza de Oliveira; Conti, Bruno José; Santiago, Karina Basso; Conte, Fernanda Lopes; Oliveira, Lucas Pires Garcia; Hernandes, Rodrigo Tavanelli; Golim, Marjorie de Assis; Sforcin, José Maurício

2017-01-01

Propolis is a natural product with a complex chemical composition. Its isolated compounds exert biological activities; however, its synergistic effects are unknown. The involvement of phenolic acids (caffeic - Caf, dihydrocinnamic - Cin and p-coumaric - Cou) alone or in combination was investigated in the action of propolis in human monocytes. Cell viability was analysed by MTT assay; TNF-α, IL-6 and IL-10 production by enzyme-linked immunosorbent assay (ELISA); cell markers expression by flow cytometry; colony-forming units were counted to assess the microbicidal activity; and H 2 O 2 production was analysed by colorimetric assay. Treatments did not affect monocytes viability. Propolis and combinations containing Caf enhanced TNF-α production by resting cells. Propolis, Cin, Cou and Caf + Cin stimulated IL-6 production. All treatments upregulated IL-10. In LPS-stimulated cells, treatments downregulated IL-6 and maintained TNF-α and IL-10 production. A lower TLR-2 expression was seen than propolis. Caf + Cin enhanced TLR-4 expression. Propolis, Caf and Caf + Cin stimulated H 2 O 2 production, whereas propolis, Cin, Cou, and Caf + Cin + Cou induced a higher fungicidal activity. Cin and Cin + Cou increased the bactericidal activity of human monocytes. Propolis activated human monocytes, and acids were involved differently in propolis activity. © 2016 Royal Pharmaceutical Society.

Bromelain treatment leads to maturation of monocyte-derived dendritic cells but cannot replace PGE2 in a cocktail of IL-1β, IL-6, TNF-α and PGE2.

PubMed

Karlsen, M; Hovden, A-O; Vogelsang, P; Tysnes, B B; Appel, S

2011-08-01

Immunotherapy using dendritic cells (DC) has shown promising results. However, the use of an appropriate DC population is critical for the outcome of this treatment, and the search for an optimal DC subset is still ongoing. The DC used in immunotherapy today are usually matured with a cytokine cocktail consisting of TNF-α, IL-1β, IL-6 and PGE(2). These cells have deficits in their cytokine production, particularly IL-12p70, mainly because of the presence of PGE(2). Bromelain is a pineapple stem extract containing a mixture of proteases that has been used clinically in adjuvant cancer treatment. In this study, we analysed the effect of bromelain on human monocyte-derived DC. We added bromelain to the cytokine cocktail and modified cytokine cocktails with either no PGE(2) or reduced amounts of PGE(2), respectively. Combining bromelain with the cytokine cocktails containing PGE(2) resulted in an increased surface expression of CD83, CD80 and CD86. The chemokine receptor CCR7 was also considerably upregulated in these DC populations compared with DC treated with the cytokine cocktail alone. Removal or reduction of PGE(2) from the cytokine cocktail did not increase the IL-12p70 secretion from stimulated DC, and addition of bromelain to the different cytokine cocktails resulted in only a minor increase in IL-12p70 production. Moreover, combining bromelain with the cytokine cocktails did not improve the T cell stimulatory capacity of the generated DC populations. In conclusion, bromelain treatment of monocyte-derived DC does not improve the functional quality compared with the standard cytokine cocktail. © 2011 The Authors. Scandinavian Journal of Immunology © 2011 Blackwell Publishing Ltd.

Characterization of lipopolysaccharide-stimulated cytokine expression in macrophages and monocytes

USDA-ARS?s Scientific Manuscript database

Inflammation plays a pivotal role in several chronic human conditions and diseases including atherosclerosis, ischemic heart disease, cancer, obesity, diabetes, and autoimmune diseases. In vitro cell culture models such as exposure of mouse macrophage J774A.1 and human monocyte THP-1 cells to bacter...

Skin-resident CD4+ T cells protect against Leishmania major by recruiting and activating inflammatory monocytes

PubMed Central

Glennie, Nelson D.; Volk, Susan W.

2017-01-01

Tissue-resident memory T cells are required for establishing protective immunity against a variety of different pathogens, although the mechanisms mediating protection by CD4+ resident memory T cells are still being defined. In this study we addressed this issue with a population of protective skin-resident, IFNγ-producing CD4+ memory T cells generated following Leishmania major infection. We previously found that resident memory T cells recruit circulating effector T cells to enhance immunity. Here we show that resident memory CD4+ T cells mediate the delayed-hypersensitivity response observed in immune mice and provide protection without circulating T cells. This protection occurs rapidly after challenge, and requires the recruitment and activation of inflammatory monocytes, which limit parasites by production of both reactive oxygen species and nitric oxide. Overall, these data highlight a novel role for tissue-resident memory cells in recruiting and activating inflammatory monocytes, and underscore the central role that skin-resident T cells play in immunity to cutaneous leishmaniasis. PMID:28419151

Modulation of dendritic cell and monocyte subsets in tuberculosis-diabetes co-morbidity upon standard tuberculosis treatment

PubMed Central

Kumar, Nathella Pavan; Moideen, Kadar; Sivakumar, Shanmugam; Menon, Pradeep A; Viswanathan, Vijay; Kornfeld, Hardy; Babu, Subash

2016-01-01

Type 2 diabetes mellitus (DM) is a major risk factor for the development of active pulmonary tuberculosis (PTB), with development of DM pandemic in countries where tuberculosis (TB) is also endemic. However, the effect of anti-TB treatment on the changes in dentritic cell (DC) and monocyte subset phenotype in TB-DM co-morbidity is not well understood. In this study, we characterized the frequency of DC and monocyte subsets in individuals with PTB with (PTB-DM) or without coincident diabetes mellitus (PTB-NDM) before, during and after completion of anti-TB treatment. PTB-DM is characterized by diminished frequencies of plasmacytoid and myeloid DCs and classical and intermediate monocytes at baseline and 2 months of anti-TB treatment but not following 6 months of treatment completion in comparison to PTB-NDM. DC and monocyte subsets exhibit significant but borderline correlation with fasting blood glucose and glycated hemoglobin levels. Finally, while minor changes in the DC and monocyte compartment were observed at 2 months of treatment, significantly increased frequencies of plasmacytoid and myeloid DCs and classical and intermediate monocytes were observed at the successful completion of anti-TB treatment. Our data show that coincident diabetes alters the frequencies of innate subset distribution of DC and monocytes in TB-DM co-morbidity and suggests that most of these changes are reversible following anti-TB therapy. PMID:27865391