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Sample records for human monocytes treated

  1. Serine leucocyte proteinase inhibitor-treated monocyte inhibits human CD4(+) lymphocyte proliferation.

    PubMed

    Guerrieri, Diego; Tateosian, Nancy L; Maffía, Paulo C; Reiteri, Romina M; Amiano, Nicolás O; Costa, María J; Villalonga, Ximena; Sanchez, Mercedes L; Estein, Silvia M; Garcia, Verónica E; Sallenave, Jean-Michel; Chuluyan, Héctor E

    2011-08-01

    Serine leucocyte proteinase inhibitor (SLPI) is the main serine proteinase inhibitor produced by epithelial cells and has been shown to be a pleiotropic molecule with anti-inflammatory and microbicidal activities. However, the role of SLPI on the adaptive immune response is not well established. Therefore, we evaluated the effect of SLPI on lymphocyte proliferation and cytokine production. Human peripheral blood mononuclear cells (PBMC) were treated with mitogens plus SLPI and proliferation was assessed by [(3) H]thymidine uptake. The SLPI decreased the lymphocyte proliferation induced by interleukin-2 (IL-2) or OKT3 monoclonal antibodies in a dose-dependent manner. Inhibition was not observed when depleting monocytes from the PBMC and it was restored by adding monocytes and SLPI. SLPI-treated monocyte slightly decreased MHC II and increased CD18 expression, and secreted greater amounts of IL-4, IL-6 and IL-10 in the cell culture supernatants. SLPI-treated monocyte culture supernatant inhibited the CD4(+) lymphocyte proliferation but did not affect the proliferation of CD8(+) cells. Moreover, IL-2 increased T-bet expression and the presence of SLPI significantly decreased it. Finally, SLPI-treated monocyte culture supernatant dramatically decreased interferon-γ but increased IL-4, IL-6 and IL-10 in the presence of IL-2-treated T cells. Our results demonstrate that SLPI target monocytes, which in turn inhibit CD4 lymphocyte proliferation and T helper type 1 cytokine secretion. Overall, these results suggest that SLPI is an alarm protein that modulates not only the innate immune response but also the adaptive immune response. PMID:21574992

  2. Serine leucocyte proteinase inhibitor-treated monocyte inhibits human CD4+ lymphocyte proliferation

    PubMed Central

    Guerrieri, Diego; Tateosian, Nancy L; Maffía, Paulo C; Reiteri, Romina M; Amiano, Nicolás O; Costa, María J; Villalonga, Ximena; Sanchez, Mercedes L; Estein, Silvia M; Garcia, Verónica E; Sallenave, Jean-Michel; Chuluyan, Héctor E

    2011-01-01

    Serine leucocyte proteinase inhibitor (SLPI) is the main serine proteinase inhibitor produced by epithelial cells and has been shown to be a pleiotropic molecule with anti-inflammatory and microbicidal activities. However, the role of SLPI on the adaptive immune response is not well established. Therefore, we evaluated the effect of SLPI on lymphocyte proliferation and cytokine production. Human peripheral blood mononuclear cells (PBMC) were treated with mitogens plus SLPI and proliferation was assessed by [3H]thymidine uptake. The SLPI decreased the lymphocyte proliferation induced by interleukin-2 (IL-2) or OKT3 monoclonal antibodies in a dose-dependent manner. Inhibition was not observed when depleting monocytes from the PBMC and it was restored by adding monocytes and SLPI. SLPI-treated monocyte slightly decreased MHC II and increased CD18 expression, and secreted greater amounts of IL-4, IL-6 and IL-10 in the cell culture supernatants. SLPI-treated monocyte culture supernatant inhibited the CD4+ lymphocyte proliferation but did not affect the proliferation of CD8+ cells. Moreover, IL-2 increased T-bet expression and the presence of SLPI significantly decreased it. Finally, SLPI-treated monocyte culture supernatant dramatically decreased interferon-γ but increased IL-4, IL-6 and IL-10 in the presence of IL-2-treated T cells. Our results demonstrate that SLPI target monocytes, which in turn inhibit CD4 lymphocyte proliferation and T helper type 1 cytokine secretion. Overall, these results suggest that SLPI is an alarm protein that modulates not only the innate immune response but also the adaptive immune response. PMID:21574992

  3. Activated macrophages for treating skin ulceration: gene expression in human monocytes after hypo-osmotic shock

    PubMed Central

    FRENKEL, O; SHANI, E; BEN-BASSAT, I; BROK-SIMONI, F; ROZENFELD-GRANOT, G; KAJAKARO, G; RECHAVI, G; AMARIGLIO, N; SHINAR, E; DANON, D

    2002-01-01

    Macrophages play a major role in almost all stages of the complex process of wound healing. It has been previously shown that the incorporation of a hypo-osmotic shock step, in the process of monocyte-concentrate preparation from a blood unit, induces monocyte/macrophage activation. As the macrophages are produced using a unique, closed and sterile system, they are suitable for local application on ulcers in elderly and paraplegic patients. Enhanced phagocytosis by the activated cells, as well as increased secretion of cytokines such as IL-1, IL-6, were detected in a recent study which are in accord with the very encouraging clinical results. In the present study, we used DNA microarrays to analyse the differential gene expressions of the hypo-osmotic shock-activated monocytes/macrophages and compare them to non-treated cells. Of the genes that exhibited differences of expression in the activated cell population, 94% (68/72) displayed increased activity. The mRNA levels of 43/68 of these genes (63%) were found to be 1·5-fold or higher (1·5–7·98) in the activated macrophages cell population as compared to the non-treated cells. Only four genes were found to have lower mRNA levels in the activated cells, with ratios of expression of 0·62–0·8, which may suggest that the changes are insignificant. A significant number of the genes that showed increased levels of expression is known to be directly involved in macrophage function and wound healing. This may correlate with the increased secretion of different cytokines by the activated macrophages depicted previously. Other groups of genes expressed are known to be involved in important pathways such as neuronal growth and function, developmental defects and cancer. The hypo-osmotic shock induces a gene expression profile of cytokines and receptors in the activated cells. These may evoke potential abilities to produce a variety of protein products needed in the wound healing process and may bring to light

  4. Attenuation of monocyte adhesion and oxidised LDL uptake in luteolin-treated human endothelial cells exposed to oxidised LDL.

    PubMed

    Jeong, Yu-Jin; Choi, Yean-Jung; Choi, Jung-Suk; Kwon, Hyang-Mi; Kang, Sang-Wook; Bae, Ji-Young; Lee, Sang-Soo; Kang, Jung-Sook; Han, Seoung Jun; Kang, Young-Hee

    2007-03-01

    Oxidative modification of LDL is causally involved in the development of atherosclerosis and occurs in vivo in the blood as well as within the vascular wall. The present study attempted to explore whether polyphenolic flavonoids influence monocyte-endothelium interaction and lectin-like oxidised LDL receptor 1 (LOX-1) expression involved in the early development of atherosclerosis. The flavones luteolin and apigenin inhibited THP-1 cell adhesion onto oxidised LDL-activated human umbilical vein endothelial cells (HUVEC), while the flavanols of (-)epigallocatechin gallate and (+)catechin, the flavonols of quercetin and rutin, and the flavanones of naringin, naringenin, hesperidin and hesperetin did not have such effects. Consistently, Western blot analysis revealed that the flavones at 25 microM dramatically and significantly abolished HUVEC expression of vascular cell adhesion molecule-1 and E-selectin evidently enhanced by oxidised LDL; these inhibitory effects were exerted by drastically down regulating mRNA levels of these cell adhesion molecules. In addition, quercetin and luteolin significantly attenuated expression of LOX-1 protein up regulated in oxidised LDL-activated HUVEC with a fall in transcriptional mRNA levels of LOX-1. In addition, quercetin and luteolin clearly blunted oxidised LDL uptake by HUVEC treated with oxidised LDL. The results demonstrate that the flavones luteolin and apigenin as well as quercetin were effective in the different initial steps of atherosclerosis process by inhibiting oxidised LDL-induced endothelial monocyte adhesion and/or oxidised LDL uptake. Therefore, certain flavonoids qualify as anti-atherogenic agents in LDL systems, which may have implications for strategies attenuating endothelial dysfunction-related atherosclerosis. PMID:17313705

  5. Changes of cell-surface thiols and intracellular signaling in human monocytic cell line THP-1 treated with diphenylcyclopropenone.

    PubMed

    Hirota, Morihiko; Motoyama, Akira; Suzuki, Mie; Yanagi, Masashi; Kitagaki, Masato; Kouzuki, Hirokazu; Hagino, Shigenobu; Itagaki, Hiroshi; Sasa, Hitoshi; Kagatani, Saori; Aiba, Setsuya

    2010-12-01

    Changes of cell-surface thiols induced by chemical treatment may affect the conformations of membrane proteins and intracellular signaling mechanisms. In our previous study, we found that a non-toxic dose of diphenylcyclopropene (DPCP), which is a potent skin sensitizer, induced an increase of cell-surface thiols in cells of a human monocytic cell line, THP-1. Here, we examined the influence of DPCP on intracellular signaling. First, we confirmed that DPCP induced an increase of cell-surface thiols not only in THP-1 cells, but also in primary monocytes. The intracellular reduced-form glutathione/oxidized-form glutathione ratio (GSH/GSSG ratio) was not affected by DPCP treatment. By means of labeling with a membrane-impermeable thiol-reactive compound, Alexa Fluor 488 C5 maleimide (AFM), followed by two-dimensional gel electrophoresis and analysis by liquid chromatography coupled with electrospray tandem mass spectrometry (LC/MS/MS), we identified several proteins whose thiol contents were modified in response to DPCP. These proteins included cell membrane components, such as actin and β-tubulin, molecular chaperones, such as heat shock protein 27A and 70, and endoplasmic reticulum (ER) stress-inducible proteins. Next, we confirmed the expression in DPCP-treated cells of spliced XBP1, a known marker of ER stress. We also detected the phosphorylation of SAPK/JNK and p38 MAPK, which are downstream signaling molecules in the IRE1α-ASK1 pathway, which is activated by ER stress. These data suggested that increase of cell-surface thiols might be associated with activation of ER stress-mediated signaling. PMID:21139337

  6. Successful Treatment of Human Monocytic Ehrlichiosis with Rifampin

    PubMed Central

    Ajmal, Saira; Hughes, Laura

    2016-01-01

    Currently recommended treatment regimens for human monocytic ehrlichiosis (HME) include doxycycline or tetracycline. Antibiotic susceptibility studies demonstrate that rifampin has in vitro bactericidal activity against Ehrlichia. Case reports have suggested clinical response with rifampin treatment of human granulocytic anaplasmosis (HGA). We report the first case of HME successfully treated with rifampin. PMID:26918212

  7. Sources of heterogeneity in human monocyte subsets

    PubMed Central

    Appleby, Laura J.; Nausch, Norman; Midzi, Nicholas; Mduluza, Takafira; Allen, Judith E.; Mutapi, Francisca

    2013-01-01

    Human monocytes are commonly defined and discriminated by the extent of their cell surface expression of CD14 and CD16, with associated differences in function and phenotype related to the intensity of expression of these markers. With increasing interest into the function and behaviour of monocytes, it is important to have a clear understanding of how differing strategies of analysis can affect results and how different protocols and population backgrounds can affect this highly morphogenic cell type. Using PBMCs from populations with differing ethnicities and histories of parasite exposure we have characterized monocyte phenotype based on intensity of CD14 and CD16 expression. Using the surface markers HLA-DR, CCR2 and CX3CR1, we compared monocyte phenotype between populations and further assessed changes in monocytes with freezing and thawing of PBMCs. Our results reveal that there is a progression of surface marker expression based on intensity of CD14 or CD16 expression, stressing the importance of careful gating of monocyte subtypes. Freezing and thawing of the PBMCs has no effect generally on the monocytes, although it does lead to a decrease in CD16 and CX3CR1 expression. We show that there are differences in the monocyte populations based on ethnicity and history of exposure to the common parasites Plasmodium falciparum and Schistosoma haematobium. This study highlights that blood monocytes consist of a continuous population of cells, within which the dominant phenotype may vary dependent on the background of the study population. Comparing results from monocyte studies therefore needs to be done with great care, as ethnic background of donor population, gating strategy and processing of PBMCs may all have an effect on outcome of monocyte phenotype. PMID:23557598

  8. Primary human monocyte differentiation regulated by Nigella sativa pressed oil

    PubMed Central

    2011-01-01

    Background Oxidized low density lipoprotein plays an important role in development of foam cells in atherosclerosis. The study was focused on regulation of primary human monocyte growth and CD11b expression in presence of Nigella sativa oil. Methods Primary human monocytes were isolated from whole blood and grown at 37°C and 5% CO2 saturation for five days prior to treatment with Nigella sativa oil. The cells were plated and washed before treatment with ox-LDL (10 μg/ml) as positive control and combined treatment of ox-LDL (10 μg/ml) and (140 ng/ml) Nigella sativa oil. The growth progression was monitored every 24 hours for 3 days. Results Macrophages showed reduced growth in comparison to monocytes 24 hours after treatment with Nigella sativa oil. The mean cell diameter was significantly different between untreated and treated condition in monocytes and macrophages (p < 0.001). Similarly, intracellular lipid accumulation was hindered in combined treatment with Nigella sativa oil. This was further supported by cell surface expression analysis, where CD11b was markedly reduced in cells treated with combination oxLDL and Nigella sativa oil compared to oxLDL alone. More cells differentiated into macrophage-like cells when monocytes were supplemented with oxidized LDL alone. Conclusions The finding provides preliminary evidence on regulation of cell growth and differentiation in monocyte and monocyte-derived macrophages by Nigella sativa oil. Further investigations need to be conducted to explain its mechanism in human monocyte. PMID:22104447

  9. Effect of prostaglandin I2 analogs on monocyte chemoattractant protein-1 in human monocyte and macrophage.

    PubMed

    Tsai, Ming-Kai; Hsieh, Chong-Chao; Kuo, Hsuan-Fu; Lee, Min-Sheng; Huang, Ming-Yii; Kuo, Chang-Hung; Hung, Chih-Hsing

    2015-08-01

    Chemokines play essential roles during inflammatory responses and in pathogenesis of inflammatory diseases. Monocyte chemotactic protein-1 (MCP-1) is a critical chemokine in the development of atherosclerosis and acute cardiovascular syndromes. MCP-1, by its chemotactic activity, causes diapedesis of monocytes from the lumen to the subendothelial space that leads to atherosclerotic plaque formation. Prostaglandin I2 (PGI2) analogs are used clinically for patients with pulmonary hypertension and have anti-inflammatory effects. However, little is known about the effect of PGI2 analogs on the MCP-1 production in human monocytes and macrophages. We investigated the effects of three conventional (iloprost, beraprost and treprostinil) and one new (ONO-1301) PGI2 analogs, on the expression of MCP-1 expression in human monocytes and macrophages. Human monocyte cell line, THP-1 cell, was treated with PGI2 analogs after LPS stimulation. Supernatants were harvested to measure MCP-1 levels and measured by ELISA. To explore which receptors involved the effects of PGI2 analogs on the expression of MCP-1 expression, IP and EP, PPAR-α and PPAR-γ receptor antagonists were used. Forskolin, a cAMP activator, was used to further confirm the involvement of cAMP on MCP-1 production in human monocytes. Three PGI2 analogs suppressed LPS-induced MCP-1 production in THP-1 cells and THP-1-induced macrophages. Higher concentrations of ONO-1301 also had the suppressive effect. CAY 10449, an IP receptor antagonist, could reverse the effects on MCP-1 production of iloprost on THP-1 cells. Other reported PGI2 receptor antagonists including EP1, EP2, EP4, PPAR-α and PPAR-γ antagonists could not reverse the effect. Forskolin, a cAMP activator, also suppressed MCP-1 production in THP-1 cells. PGI2 analogs suppressed LPS-induced MCP-1 production in human monocytes and macrophages via the IP receptor and cAMP pathway. The new PGI2 analog (ONO-1301) was not better than conventional PGI2 analog in

  10. Lactic acid delays the inflammatory response of human monocytes

    SciTech Connect

    Peter, Katrin; Rehli, Michael; Singer, Katrin; Renner-Sattler, Kathrin; Kreutz, Marina

    2015-02-13

    Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors.

  11. Initial Characterization of Monoclonal Antibodies against Human Monocytes

    NASA Astrophysics Data System (ADS)

    Ugolini, Valentina; Nunez, Gabriel; Smith, R. Graham; Stastny, Peter; Capra, J. Donald

    1980-11-01

    Three monoclonal antibodies against human monocytes have been produced by somatic cell fusion. Extensive specificity analysis suggests that these antibodies react with most if not all human peripheral blood monocytes and not with highly purified T or B cells. Initial chemical characterization of the monocyte antigen recognized by two of these antibodies is presented. The molecule is a single polypeptide chain with an apparent molecular weight of 200,000. These reagents should prove useful in the clinical definition of disorders of monocyte differentiation, in studies of monocyte function, and in the elucidation of the genetics and structure of monocyte cell surface antigens.

  12. Inhibition of human monocyte respiratory burst, degranulation, phospholipid methylation and bactericidal activity by pneumolysin.

    PubMed Central

    Nandoskar, M; Ferrante, A; Bates, E J; Hurst, N; Paton, J C

    1986-01-01

    The interaction between the pneumococcal toxin pneumolysin and human monocytes was examined. At non-cytotoxic concentrations (0.5-2.5 HU/10(6) cells) pneumolysin depressed the oxygen-dependent respiratory burst in monocytes, induced by opsonized zymosan or phorbol myristate acetate (PMA). This included depressed hexose-monophosphate shunt activity and hydrogen peroxide production. The toxin also depressed the ability of monocytes to degranulate (measured by release of lysozyme) in response to the above stimuli. Phospholipid transmethylation was also markedly decreased by pretreating monocytes with pneumolysin. These effects on monocyte functions were accompanied by a decreased ability of pneumolysin-treated monocytes to kill Streptococcus pneumoniae, the organism that produces the toxin. Cholesterol, which inhibits the haemolytic activity of the toxin, was shown to abrogate the effects of pneumolysin on monocytes. PMID:3804376

  13. Human Monocytes Engage an Alternative Inflammasome Pathway.

    PubMed

    Gaidt, Moritz M; Ebert, Thomas S; Chauhan, Dhruv; Schmidt, Tobias; Schmid-Burgk, Jonathan L; Rapino, Francesca; Robertson, Avril A B; Cooper, Matthew A; Graf, Thomas; Hornung, Veit

    2016-04-19

    Interleukin-1β (IL-1β) is a cytokine whose bioactivity is controlled by activation of the inflammasome. However, in response to lipopolysaccharide, human monocytes secrete IL-1β independently of classical inflammasome stimuli. Here, we report that this constituted a species-specific response that is not observed in the murine system. Indeed, in human monocytes, lipopolysaccharide triggered an "alternative inflammasome" that relied on NLRP3-ASC-caspase-1 signaling, yet was devoid of any classical inflammasome characteristics including pyroptosome formation, pyroptosis induction, and K(+) efflux dependency. Genetic dissection of the underlying signaling pathway in a monocyte transdifferentiation system revealed that alternative inflammasome activation was propagated by TLR4-TRIF-RIPK1-FADD-CASP8 signaling upstream of NLRP3. Importantly, involvement of this signaling cascade was limited to alternative inflammasome activation and did not extend to classical NLRP3 activation. Because alternative inflammasome activation embraces both sensitivity and promiscuity of TLR4, we propose a pivotal role for this signaling cascade in TLR4-driven, IL-1β-mediated immune responses and immunopathology in humans. PMID:27037191

  14. Effect of PIP3 on Adhesion Molecules and Adhesion of THP-1 Monocytes to HUVEC Treated with High Glucose

    PubMed Central

    Su, Prasenjit Manna; Jain, shil K.

    2014-01-01

    Background Phosphatidylinositol-3,4,5-triphosphate (PIP3), a well-known lipid second messenger, plays a key role in insulin signaling and glucose homeostasis. Using human umbilical vein endothelial cells (HUVEC) and THP-1 monocytes, we tested the hypothesis that PIP3 can downregulate adhesion molecules and monocyte adhesion to endothelial cells. Methods HUVEC and monocytes were exposed to high glucose (HG, 25 mM, 20 h) with or without PIP3 (0-20 nM), or PIT-1 (25 μM), an inhibitor of PIP3. Results Both HG and PIT-1 caused a decrease in cellular PIP3 in monocytes and HUVEC compared to controls. Treatment with PIT-1 and HG also increased the ICAM-1 (intercellular adhesion molecule 1) total protein expression as well as its surface expression in HUVEC, CD11a (a subunit of lymphocyte function-associated antigen 1, LFA-1) total protein expression as well as its surface expression in monocytes, and adhesion of monocytes to HUVEC. Exogenous PIP3 supplementation restored the intracellular PIP3 concentrations, downregulated the expression of adhesion molecules, and reduced the adhesion of monocytes to HUVEC treated with HG. Conclusion This study reports that a decrease in cellular PIP3 is associated with increased expression of adhesion molecules and monocyte-endothelial cell adhesion, and may play a role in the endothelial dysfunction associated with diabetes. PMID:24752192

  15. 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

  16. Interaction between human peripheral blood monocytes and tumor promoters: Effect on growth differentiation and function in vitro

    SciTech Connect

    Keisari, Y.; Bucana, C.; Markovich, S.; Campbell, D.E. )

    1990-08-01

    Studies on the differentiation and activation of human monocytes in tissue cultures have usually been limited by the deterioration of human monocytes and macrophages in long-term cultures. In this study, we attempted to establish long-term human monocyte/macrophage cultures using the phorbol ester 12-0 tetradecanoyl-phorbol-13-acetate (TPA), and we studied the morphology, function, and biochemical properties of such treated human blood monocytes. Enriched suspensions of monocytes were obtained using Ficoll-Hypaque gradient and cultured in the absence or presence of various concentrations of TPA. Samples were removed at different times and processed for scanning electron microscopy. Parallel samples were examined for numbers of adherent cells, phagocytosis, oxidative burst, beta-galactosidase assays, and lectin-mediated erythrolysis. TPA-treated monocytes survived in larger numbers in culture for up to 7 weeks and were more pleomorphic and exhibited higher beta-galactosidase activities after 14 days in culture than untreated monocytes. TPA-treated cells and untreated cells in long-term cultures showed a decrease in their oxidative burst activity while their phagocytic activity was not affected, and the TPA treatment augmented the lysis of wheat germ agglutinin-opsonized erythrocytes by the cultured monocytes. TPA treatment of adherent human monocytes resulted in cell cultures with increased numbers of viable and functionally adherent cells for extended periods of time and does not seem to interfere with the differentiation and maturation of the cells in culture.

  17. Radiation effects on cultured human monocytes and on monocyte-derived macrophages

    SciTech Connect

    Buescher, E.S.; Gallin, J.I.

    1984-06-01

    Prior to administration, leukocyte transfusions are commonly irradiated with up to 5,000 R to eliminate lymphocytes and thereby prevent graft-versus-host disease in the recipient. It has been widely believed that phagocytes are resistant to this irradiation. In a recent report, it was noted that phagocyte oxidative metabolism was compromised during preparation of white cells for transfusion. As part of the effort to examine the basis for this inhibition of phagocyte function during white cell preparation, an assessment was made of the effects of irradiation on the long-lived monocytes that have been shown to persist at inflammatory foci posttransfusion. Human monocytes were irradiated for up to 3 min, receiving 2,500-5,000 R. This irradiation damaged human monocytes, significantly decreasing their in vitro survival for the first 3 wk of culture, and growth as assessed by two-dimensional cell size measurements during the first 2 wk of culture. Despite smaller cell size, total cell protein was significantly increased over time in irradiated cultures. Extracellular release of lysozyme and beta-glucuronidase per cell was not affected by irradiation, but extracellular lactate dehydrogenase (LDH) release was significantly increased after irradiation. Irradiated monocytes killed Listeria monocytogenes at a slower rate than the nonirradiated controls. Thus, the data indicate that irradiation in doses used to prevent graft-versus-host disease in leukocyte transfusion recipients has a deleterious effect on in vitro human monocyte survival and function.

  18. Human monocyte adherence measured by the nylon fibre microcolumn technique.

    PubMed

    Kelly, M K; Thong, Y H

    1984-11-30

    A simple rapid method for the measurement of human monocyte adherence using nylon fibre microcolumns is described. The kinetics indicate the optimal contact time to be 30 min for monocytes, compared with 10 min for neutrophils. The optimal temperature is 37 degrees C; significantly low values were obtained for 4 degrees C and 45 degrees C, while intermediate values were obtained for 25 degrees C. Monocyte adherence was more sensitive to inhibition by fluoride than cyanide, suggesting that energy for adherence is mainly derived from the glycolytic pathway. The addition of phorbol myristate acetate enhances monocyte adherence. Significant decay in monocyte adherence occurred after isolation from whole blood for 24 h or longer. PMID:6501891

  19. 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

  20. Folate receptor-β constitutes a marker for human proinflammatory monocytes

    PubMed Central

    Shen, Jiayin; Hilgenbrink, Andrew R.; Xia, Wei; Feng, Yang; Dimitrov, Dimiter S.; Lockwood, Michael B.; Amato, Robert J.; Low, Philip S.

    2014-01-01

    Activated macrophages are commonly involved in the pathogenesis of inflammatory and autoimmune diseases and have been frequently reported to overexpress FR-β. Although FR-targeted therapies aimed at eliminating activated macrophages have shown promise for treating inflammatory diseases, little work has been performed to evaluate whether other hematopoietic cells might also express FR-β. Analysis of peripheral blood cells with a mAb to human FR-β reveals that only monocytes express FR-β. Molecular characterization of these circulating monocytes further demonstrates that solely the classic/proinflammatory subset (CD14highCD16−) expresses the FR and that only CD14highCD16− FR-β+ monocytes also display the ability to bind folate-linked molecules. Confirmation that this subset of monocytes indeed constitutes the proinflammatory subpopulation was obtained by demonstrating coexpression of FR-β with other proinflammatory markers, including CCR2 and HLA-DR. Synovial monocytes from the joints of patients with RA were also shown to express FR-β. As inhibition of the chemotaxis of proinflammatory monocytes into sites of inflammation has been explored frequently as a means of controlling autoimmune diseases, demonstration that FR-β is uniquely expressed on this proinflammatory subpopulation offers a new strategy to suppress migration of inflammatory monocytes into sites of inflammation. PMID:25015955

  1. Cytokine-activated human endothelial cells synthesize and secrete a monocyte chemoattractant, MCP-1/JE.

    PubMed Central

    Rollins, B. J.; Yoshimura, T.; Leonard, E. J.; Pober, J. S.

    1990-01-01

    We have demonstrated inducible expression of the mRNA encoding the monocyte chemoattractant MCP-1, the human homolog of the JE gene, in endothelial cells within 3 hours of treatment with IL-1 beta and tumor necrosis factor. IFN-gamma also induced expression of this mRNA after 24 hours, but to a lesser extent. MCP-1/JE protein steadily accumulated in the medium of endothelial cells during a 48-hour exposure to IL-1 beta. Medium conditioned by IL-1 beta-treated endothelial cells contained monocyte chemoattractant activity that was immunoadsorbed by anti-MCP-1 antibodies. These results suggest that endothelial cells secrete a monocyte chemoattractant, MCP-1/JE, in response to inflammatory mediators, and thus may contribute to the accumulation of monocytes at sites of inflammation. Images Figure 1 Figure 2 PMID:2113354

  2. Studies on the metabolism of triphenylphosphate by carboxylesterases and human monocytes

    SciTech Connect

    Paxman, D.G. III.

    1988-01-01

    Resin workers exposed to triphenylphosphate (TPP), an organophosphate (OP) flame retardant and plasticizer, had a decreased expression of carboxylesterase (CBE) activity in their peripheral blood monocytes. The mechanisms of CBE inhibition by TPP were investigated using purified hog liver CBE and intact human monocytes. TPP inactivated hog liver CBE in a time and dose dependent manner, and this inhibition was partially reversed by alkaline phosphatase (AP). Analysis of ({sup 14}C)TPP metabolites from the enzymatic reaction by high performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GM-C) identified phenol as the hydrolytic metabolite of TPP. Human monocytes cultured with ({sup 14}C)TPP also released phenol. In addition to phenol, several phenol metabolites, such as catechol, hydroquinone, 2,2 biphenol and 4,4 biphenol were also generated by monocytes. An identical pattern of these metabolites was also formed from monocytes incubated with radiolabelled phenol. This cellular degradation of TPP was inhibited by diisopropylfluorophosphate (DFP), but not observed in neutrophil or lymphocyte cultures. Activation of monocytes with gamma interferon (IFN-g), f-Met-Leu-Phe, and serum treated zymosan (STZ) enhanced the levels of phenolic metabolites and, further, shifted the metabolism of TPP towards the formation of the biphenolic metabolites.

  3. Effects of 4-chlorotestosterone acetate on the phagocytic activity of human monocytes: results of double-blind trial

    PubMed Central

    Magliulo, E.; Giraldi, M.; Cattaneo, E.; Marchioni, E.

    1972-01-01

    A comparative trial on 4-chlorotestosterone acetate and placebo was conducted in humans by the double-blind technique. The effects of the drug were tested by measuring the phagocytic activity of blood monocytes in vitro for colloidal carbon. Monocytes from patients treated with 4-chlorotestosterone acetate displayed a phagocytic power significantly higher than that of monocytes from patients treated with the placebo. Such an increased phagocytic activity is discussed in relation to cell mechanisms and their role in anti-infective defence. ImagesFig. 1 PMID:4556011

  4. No evidence for histamine H4 receptor in human monocytes.

    PubMed

    Werner, Kristin; Neumann, Detlef; Buschauer, Armin; Seifert, Roland

    2014-12-01

    The histamine H4 receptor (H4R) is a classic pertussis toxin-sensitive Gi protein-coupled receptor that mediates increases in intracellular calcium concentration ([Ca(2+)]i). The presence of H4R in human eosinophils has been rigorously documented by several independent groups. It has also been suggested that H4R is expressed in human monocytes, but this suggestion hinges in part on H4R antibodies with questionable specificity. This situation prompted us to reinvestigate H4R expression in human monocytes. As positive control, we studied human embryonic kidney 293T cells stably expressing the human H4R (hH4R). In these cells, histamine (HA) and the H4R agonist UR-PI376 (2-cyano-1-[4-(1H-imidazol-4-yl)butyl]-3-[(2-phenylthio)ethyl]guanidine) induced pertussis toxin-sensitive [Ca(2+)]i increases. However, in quantitative real-time polymerase chain reaction studies we failed to detect hH4R mRNA in human monocytes and U937 promonocytes. In human monocytes, ATP and N-formyl-l-methionyl-l-leucyl-l-phenylalanine increased [Ca(2+)]i, but HA, UR-PI376, and 5-methylhistamine (a dual H4R/H2 receptor agonist) did not. In U937 promonocytes and differentiated U937 cells, HA increased [Ca(2+)]i, but this increase was mediated via HA H1 receptor. In conclusion, there is no evidence for the presence of H4R in human monocytes. PMID:25273276

  5. Monoclonal antibodies specific for human monocytes, granulocytes and endothelium.

    PubMed Central

    Hogg, N; MacDonald, S; Slusarenko, M; Beverley, P C

    1984-01-01

    Four monoclonal antibodies against antigens of human myeloid cells have been produced and thoroughly characterized in terms of their reactions with peripheral blood cells, cell lines, nine lymphoid and non-lymphoid tissues and the polypeptides with which they react. UCHM1 and SmO identify antigens present on the majority of blood monocytes and a variable, but lower, proportion of tissue macrophages. From their morphology and location in tissues, these cells appear to be recirculating monocytes. SMO antigen is also present on platelets. In addition, both antibodies stained endothelial cells, SMO in all tissues examined and UCHM1 variably. Biochemical investigation indicated that the UCHM1 antigen is a protein of 52,000 MW while the SMO antigen could not be indentified. The antibodies TG1 and 28 identify antigens mainly present on granulocytes. While mAb 28 reacted with neutrophils, TG1 also stained eosinophils and stained strongly a proportion of monocytes. TG1 also reacted variably with some non-haemopoietic cell lines. Both antibodies reacted predominantly with granulocytes in tissue sections. MAb TG1 precipitated a single polypeptide of 156,000 MW from monocytes and granulocytes, while mAb 28 precipitated non-convalently associated polypeptides of 83,000 and 155,000 MW from granulocytes but only a single molecule from monocytes, corresponding to the lower MW chain of 83,000. The epitope with which mAb 28 reacts appears not to be exposed on the surface of intact monocytes. This suggests that a similar or identical 83,000 MW molecule is made by both neutrophils and monocytes, but that its expression differs according to cell type. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:6389324

  6. Growth hormone activation of human monocytes for superoxide production but not tumor necrosis factor production, cell adherence, or action against Mycobacterium tuberculosis.

    PubMed Central

    Warwick-Davies, J; Lowrie, D B; Cole, P J

    1995-01-01

    We have previously demonstrated that growth hormone (GH) is a human macrophage-activating factor which primes monocytes for enhanced production of H2O2 in vitro. This report extends our observations to other monocyte functions relevant to infection. We find that GH also primes monocytes for O2- production, to a degree similar to the effect of gamma interferon. Neither macrophage-activating factor alone stimulates monocytes to release bioactive tumor necrosis factor. However, GH, unlike gamma interferon, does not synergize with endotoxin for enhanced tumor necrosis factor production. In further contrast, GH does not alter monocyte adherence or morphology, while phagocytosis and killing of Mycobacterium tuberculosis by GH-treated monocytes are also unaffected. Therefore, despite the multiplicity of the effects of GH on the immune system in vivo, its effects on human monocytes in vitro appear to be limited to priming for the release of reactive oxygen intermediates. PMID:7591064

  7. The monocyte binding domain(s) on human immunoglobulin G.

    PubMed

    Woof, J M; Nik Jaafar, M I; Jefferis, R; Burton, D R

    1984-06-01

    Monocyte binding has previously been assigned to the C gamma 3 domain of human immunoglobulin G (IgG) largely on the ability of the pFc' fragment to inhibit the monocyte-IgG interaction. This ability is markedly reduced compared to the intact parent IgG. We find this result with a conventional pFc' preparation but this preparation is found to contain trace contamination of parent IgG as demonstrated by reactivity with monoclonal antibodies directed against C gamma 2 domain and light-chain epitopes of human IgG. Extensive immunoaffinity purification of the pFc' preparation removes its inhibitory ability indicating that this originates in the trace contamination of parent IgG (or Fc). Neither of the human IgG1 paraproteins TIM, lacking the C gamma 2 domain, or SIZ, lacking the C gamma 3 domain, are found to inhibit the monocyte-IgG interaction. The hinge-deleted IgG1 Dob protein shows little or no inhibitory ability. Indirect evidence for the involvement of the C gamma 2 domain in monocyte binding is considered. We suggest finally that the site of interaction is found either on the C gamma 2 domain alone or between the C gamma 2 and C gamma 3 domains. PMID:6235444

  8. Current management of human granulocytic anaplasmosis, human monocytic ehrlichiosis and Ehrlichia ewingii ehrlichiosis

    PubMed Central

    Thomas, Rachael J; Stephen Dumler, J; Carlyon, Jason A

    2009-01-01

    Anaplasma phagocytophilum, Ehrlichia chaffeensis and Ehrlichia ewingii are emerging tick-borne pathogens and are the causative agents of human granulocytic anaplasmosis, human monocytic ehrlichiosis and E. ewingii ehrlichiosis, respectively. Collectively, these are referred to as human ehrlichioses. These obligate intracellular bacterial pathogens of the family Anaplasmataceae are transmitted by Ixodes spp. or Amblyomma americanum ticks and infect peripherally circulating leukocytes to cause infections that range in clinical spectra from asymptomatic seroconversion to mild, severe or, in rare instances, fatal disease. This review describes: the ecology of each pathogen; the epidemiology, clinical signs and symptoms of the human diseases that each causes; the choice methods for diagnosing and treating human ehrlichioses; recommendations for patient management; and is concluded with suggestions for potential future research. PMID:19681699

  9. [The effects of PEMF on the activation of human monocytes].

    PubMed

    Chen, Xiaoying; Han, Xiaoyu; Wang, Qian; Wu, Wenchao; Liu, Xiaojing

    2012-08-01

    The aim of the present study is to investigate the effect of pulsed electromagnetic field (PEMF) on the activation of human monocytes (THP-1). Cultured THP-1 cells were exposed to PEMF stimulation with radiation of 32Hz or 64Hz respectively, using sinusoidal wave, and 1mT, twice a day, 30 minutes each time, with an interval of 8 hours, for 3 days. Those with 0Hz stimulation served as the controls. Monocytes activation was monitored by measuring both the release of monocyte chemoattractant protein-1 (MCP-1) from monocytes and their adhesion to monolayers of human umbilical vein endothelial cells (HUVECs). The adhesion of THP-1 cells to HUVECs was evaluated by cell counting method. The secretion of MCP-1 from THP-1 cells was detected by ELISA and MCP-1 mRNA expression was assessed by real time quantitative RT-PCR. The data showed that exposure to PEMF with above parameters could significantly inhibit the adhesion of THP-1 cells to HUVECs and decrease the MCP-1 mRNA and protein expression. The results demonstrated that exposure to PEMF of 1mT, 32Hz or 64Hz for 3 days could significantly inhibit the activation of THP-1 cells. PMID:23016400

  10. Effects of botulinum toxin type D on secretion of tumor necrosis factor from human monocytes

    SciTech Connect

    Imamura, K.; Spriggs, D.; Ohno, T.; Kufe, D.

    1989-05-01

    Botulinum toxins are potent neurotoxins which block the release of neurotransmitters. The effects of these toxins on hematopoietic cells, however, are unknown. Monocytes secrete a variety of polypeptide growth factors, including tumor necrosis factor (TNF). In the study reported here, the effects of botulinum toxin type D on the secretion of TNF from human monocytes were examined. The results demonstrate that biotulinum toxin type D inhibits the release of TNF from monocytes activated by lipopolysaccharide (LPS) but not by 12-O-tetradecanoylphorbol-13-acetate. Botulinum toxin type D had no detectable effect on intracellular TNF levels in LPS-treated monocytes, indicating that the effects of this toxin involve the secretory process. This inhibitory effect of botulinum toxin type D on TNF secretion from LPS-treated monocytes was partially reversed by treatment with 12-O-tetradecanoylphorbol-13-acetate or introduction of guanosine 5'-(/gamma/-thio)t-riphosphate into these cells. The results demonstrate that TNF secretion is regulated by at least two distinct guanine nucleotide-binding proteins, one responsible for the activation of phospholiphase C and another which acts as a substrate for botulinum toxin type D. ADP-ribosylation of monocyte membranes by botulinum toxin type D demonstrated the presence of three substrates with M/sub r/s of 45,000, 21,000, and 17,000. While the role of these substrates in exocytosis is unknown, the results suggest that the M/sub r/ 21,000 substrate is involved in a process other than TNF secretion.

  11. Glucocorticoids enhance the in vivo migratory response of human monocytes.

    PubMed

    Yeager, Mark P; Pioli, Patricia A; Collins, Jane; Barr, Fiona; Metzler, Sara; Sites, Brian D; Guyre, Paul M

    2016-05-01

    Glucocorticoids (GCs) are best known for their potent anti-inflammatory effects. However, an emerging model for glucocorticoid (GC) regulation of in vivo inflammation also includes a delayed, preparatory effect that manifests as enhanced inflammation following exposure to an inflammatory stimulus. When GCs are transiently elevated in vivo following exposure to a stressful event, this model proposes that a subsequent period of increased inflammatory responsiveness is adaptive because it enhances resistance to a subsequent stressor. In the present study, we examined the migratory response of human monocytes/macrophages following transient in vivo exposure to stress-associated concentrations of cortisol. Participants were administered cortisol for 6h to elevate in vivo cortisol levels to approximate those observed during major systemic stress. Monocytes in peripheral blood and macrophages in sterile inflammatory tissue (skin blisters) were studied before and after exposure to cortisol or placebo. We found that exposure to cortisol induced transient upregulation of monocyte mRNA for CCR2, the receptor for monocyte chemotactic protein-1 (MCP-1/CCL2) as well as for the chemokine receptor CX3CR1. At the same time, mRNA for the transcription factor IκBα was decreased. Monocyte surface expression of CCR2 but not CX3CR1 increased in the first 24h after cortisol exposure. Transient exposure to cortisol also led to an increased number of macrophages and neutrophils in fluid derived from a sterile inflammatory site in vivo. These findings suggest that the delayed, pro-inflammatory effects of cortisol on the human inflammatory responses may include enhanced localization of effector cells at sites of in vivo inflammation. PMID:26790757

  12. Long non-coding RNA expression in primary human monocytes.

    PubMed

    Mirsafian, Hoda; Manda, Srinivas Srikanth; Mitchell, Christopher J; Sreenivasamurthy, Sreelakshmi; Ripen, Adiratna Mat; Mohamad, Saharuddin Bin; Merican, Amir Feisal; Pandey, Akhilesh

    2016-07-01

    Long non-coding RNAs (lncRNAs) have been shown to possess a wide range of functions in both cellular and developmental processes including cancers. Although some of the lncRNAs have been implicated in the regulation of the immune response, the exact function of the large majority of lncRNAs still remains unknown. In this study, we characterized the lncRNAs in human primary monocytes, an essential component of the innate immune system. We performed RNA sequencing of monocytes from four individuals and combined our data with eleven other publicly available datasets. Our analysis led to identification of ~8000 lncRNAs of which >1000 have not been previously reported in monocytes. PCR-based validation of a subset of the identified novel long intergenic noncoding RNAs (lincRNAs) revealed distinct expression patterns. Our study provides a landscape of lncRNAs in monocytes, which could facilitate future experimental studies to characterize the functions of these molecules in the innate immune system. PMID:26778813

  13. Plasma protein adsorbed biomedical polymers: activation of human monocytes and induction of interleukin 1.

    PubMed

    Bonfield, T L; Colton, E; Anderson, J M

    1989-06-01

    These studies involved the evaluation of human monocyte/macrophage activation by biomedical polymers coated with human blood proteins. The biomedical polymers were polyethylene, polydimethylsiloxane, woven Dacron fabric, expanded polytetrafluoroethylene, Biomer, and tissue culture treated polystyrene as the control. They were adsorbed with human blood proteins: albumin, fibrinogen, fibronectin, hemoglobin, and gamma globulin. The protein adsorbed polymers were evaluated for their potential to activate the monocyte/macrophage cellular population in vitro as assessed by the induction of the monocyte/macrophage inflammatory mediator, Interleukin 1 (IL1). Suppression of IL1 was observed when protein adsorbed polymers were compared to the appropriate protein adsorbed control. Protein adsorbed polymers, when compared to polymers without protein adsorption, stimulated IL1 production. The data presented in this manuscript show the level of induction and secretion of IL1 was dependent on the biomedical polymer and the protein adsorbed, as well as the requirement of lipopolysaccharide. These results show differential interactions occur between the proteins, monocytes/macrophages, and biomedical polymers which alter activation and induction of IL1. PMID:2786877

  14. A curated compendium of monocyte transcriptome datasets of relevance to human monocyte immunobiology research

    PubMed Central

    Rinchai, Darawan; Boughorbel, Sabri; Presnell, Scott; Quinn, Charlie; Chaussabel, Damien

    2016-01-01

    Systems-scale profiling approaches have become widely used in translational research settings. The resulting accumulation of large-scale datasets in public repositories represents a critical opportunity to promote insight and foster knowledge discovery. However, resources that can serve as an interface between biomedical researchers and such vast and heterogeneous dataset collections are needed in order to fulfill this potential. Recently, we have developed an interactive data browsing and visualization web application, the Gene Expression Browser (GXB). This tool can be used to overlay deep molecular phenotyping data with rich contextual information about analytes, samples and studies along with ancillary clinical or immunological profiling data. In this note, we describe a curated compendium of 93 public datasets generated in the context of human monocyte immunological studies, representing a total of 4,516 transcriptome profiles. Datasets were uploaded to an instance of GXB along with study description and sample annotations. Study samples were arranged in different groups. Ranked gene lists were generated based on relevant group comparisons. This resource is publicly available online at http://monocyte.gxbsidra.org/dm3/landing.gsp. PMID:27158452

  15. A curated compendium of monocyte transcriptome datasets of relevance to human monocyte immunobiology research.

    PubMed

    Rinchai, Darawan; Boughorbel, Sabri; Presnell, Scott; Quinn, Charlie; Chaussabel, Damien

    2016-01-01

    Systems-scale profiling approaches have become widely used in translational research settings. The resulting accumulation of large-scale datasets in public repositories represents a critical opportunity to promote insight and foster knowledge discovery. However, resources that can serve as an interface between biomedical researchers and such vast and heterogeneous dataset collections are needed in order to fulfill this potential. Recently, we have developed an interactive data browsing and visualization web application, the Gene Expression Browser (GXB). This tool can be used to overlay deep molecular phenotyping data with rich contextual information about analytes, samples and studies along with ancillary clinical or immunological profiling data. In this note, we describe a curated compendium of 93 public datasets generated in the context of human monocyte immunological studies, representing a total of 4,516 transcriptome profiles. Datasets were uploaded to an instance of GXB along with study description and sample annotations. Study samples were arranged in different groups. Ranked gene lists were generated based on relevant group comparisons. This resource is publicly available online at http://monocyte.gxbsidra.org/dm3/landing.gsp. PMID:27158452

  16. Bacillus anthracis’ lethal toxin induces broad transcriptional responses in human peripheral monocytes

    PubMed Central

    2012-01-01

    Background Anthrax lethal toxin (LT), produced by the Gram-positive bacterium Bacillus anthracis, is a highly effective zinc dependent metalloprotease that cleaves the N-terminus of mitogen-activated protein kinase kinases (MAPKK or MEKs) and is known to play a role in impairing the host immune system during an inhalation anthrax infection. Here, we present the transcriptional responses of LT treated human monocytes in order to further elucidate the mechanisms of LT inhibition on the host immune system. Results Western Blot analysis demonstrated cleavage of endogenous MEK1 and MEK3 when human monocytes were treated with 500 ng/mL LT for four hours, proving their susceptibility to anthrax lethal toxin. Furthermore, staining with annexin V and propidium iodide revealed that LT treatment did not induce human peripheral monocyte apoptosis or necrosis. Using Affymetrix Human Genome U133 Plus 2.0 Arrays, we identified over 820 probe sets differentially regulated after LT treatment at the p <0.001 significance level, interrupting the normal transduction of over 60 known pathways. As expected, the MAPKK signaling pathway was most drastically affected by LT, but numerous genes outside the well-recognized pathways were also influenced by LT including the IL-18 signaling pathway, Toll-like receptor pathway and the IFN alpha signaling pathway. Multiple genes involved in actin regulation, signal transduction, transcriptional regulation and cytokine signaling were identified after treatment with anthrax LT. Conclusion We conclude LT directly targets human peripheral monocytes and causes multiple aberrant gene responses that would be expected to be associated with defects in human monocyte’s normal signaling transduction pathways and function. This study provides further insights into the mechanisms associated with the host immune system collapse during an anthrax infection, and suggests that anthrax LT may have additional downstream targets outside the well-known MAPK

  17. Immunomodulating and antiviral activities of Uncaria tomentosa on human monocytes infected with Dengue Virus-2.

    PubMed

    Reis, Sonia Regina I N; Valente, Ligia M M; Sampaio, André L; Siani, Antonio C; Gandini, Mariana; Azeredo, Elzinandes L; D'Avila, Luiz A; Mazzei, José L; Henriques, Maria das Graças M; Kubelka, Claire F

    2008-03-01

    Uncaria tomentosa (Willd.) DC., a large woody vine native to the Amazon and Central American rainforests has been used medicinally by indigenous peoples since ancient times and has scientifically proven immunomodulating, anti-inflammatory, cytotoxic and antioxidant activities. Several inflammatory mediators that are implicated in vascular permeability and shock are produced after Dengue Virus (DENV) infection by monocytes, the primary targets for virus replication. Here we assessed the immunoregulatory and antiviral activities from U. tomentosa-derived samples, which were tested in an in vitro DENV infection model. DENV-2 infected human monocytes were incubated with U. tomentosa hydro-alcoholic extract or either its pentacyclic oxindole alkaloid-enriched or non-alkaloid fractions. The antiviral activity was determined by viral antigen (DENV-Ag) detection in monocytes by flow cytometry. Our results demonstrated an in vitro inhibitory activity by both extract and alkaloidal fraction, reducing DENV-Ag+ cell rates in treated monocytes. A multiple microbead immunoassay was applied for cytokine determination (TNF-alpha, IFN-alpha, IL-6 and IL-10) in infected monocyte culture supernatants. The alkaloidal fraction induced a strong immunomodulation: TNF-alpha and IFN-alpha levels were significantly decreased and there was a tendency towards IL-10 modulation. We conclude that the alkaloidal fraction was the most effective in reducing monocyte infection rates and cytokine levels. The antiviral and immunomodulating in vitro effects from U. tomentosa pentacyclic oxindole alkaloids displayed novel properties regarding therapeutic procedures in Dengue Fever and might be further investigated as a promising candidate for clinical application. PMID:18279801

  18. Extracellular nucleotides regulate CCL20 release from human primary airway epithelial cells, monocytes and monocyte-derived dendritic cells.

    PubMed

    Marcet, Brice; Horckmans, Michael; Libert, Frédérick; Hassid, Sergio; Boeynaems, Jean-Marie; Communi, Didier

    2007-06-01

    Extracellular nucleotides regulate ion transport and mucociliary clearance in human airway epithelial cells (HAECs) via the activation of P2 receptors, especially P2Y(2). Therefore, P2Y(2) receptor agonists represent potential pharmacotherapeutic agents to treat cystic fibrosis (CF). Nucleotides also modulate inflammatory properties of immune cells like dendritic cells (DCs), which play an important role in mucosal immunity. Using DNA-microarray experiments, quantitative RT-PCR and cytokine measurements, we show here that UTP up-regulated approximately 2- to 3-fold the antimicrobial chemokine CCL20 expression and release in primary HAECs cultured on permeable supports at an air-liquid interface (ALI). Both P2Y(2) (ATPgammaS, UTP, INS365) and P2Y(6) (UDP, INS48823) agonists increased CCL20 release. UTP-induced CCL20 release was insensitive to NF-kappaB pathway inhibitors but sensitive to inhibitors of ERK1/2 and p38/MAPK pathways. Furthermore, UTP had no effect on interleukin-(IL)-8 release and reduced the release of both CCL20 and IL-8 induced by TNF-alpha and LPS. Accordingly, UTP reduced the capacity of basolateral supernatants of HAECs treated with TNF-alpha or LPS to induce the chemoattraction of both CD4(+) T lymphocytes and neutrophils. In addition, we show that, in monocyte-derived DCs, ATPgammaS, and UDP but not UTP/INS365-stimulated CCL20 release. Likewise, UDP but not ATPgammaS was also able to increase CCL20 release from monocytes. Pharmacological experiments suggested an involvement of P2Y(11) or P2Y(6) receptors through NF-kappaB, ERK1/2, and p38/MAPK pathways. Altogether, our data demonstrate that nucleotides may modulate chemokine release and leukocyte recruitment in inflamed airways by acting on both epithelial and immune cells. Our results could be relevant for further clinical investigations in CF. PMID:17295217

  19. Oxidized Low Density Lipoprotein Induces Differentiation and Adhesion of Human Monocytes and the Monocytic Cell Line U937

    NASA Astrophysics Data System (ADS)

    Frostegard, Johan; Nilsson, Jan; Haegerstrand, Anders; Hamsten, Anders; Wigzell, Hans; Gidlund, Magnus

    1990-02-01

    Hypercholesterolemia is a major risk factor for development of atherosclerosis. In experimental animals fed a high-cholesterol diet, monocytes adhere to the arterial endothelium and penetrate into the intima where they differentiate into macrophages and ingest lipids thus giving rise to fatty streaks, the earliest type of atherosclerotic plaque. Macrophages express few receptors for normal low density lipo-protein (LDL) but can take up oxidized LDL by way of a scavenger receptor. The present study was designed to investigate the possible role of oxidized LDL in recruitment of resident intimal macrophages. We found that oxidized LDL induced enhanced expression of major histocompatibility complex class II molecules on human monocytes and U937 cells, a well-established system for studies of monocytic differentiation. Oxidized LDL also induced enhanced expression of the surface antigen LEuM3 but caused decreased expression of CD4 antigen, a pattern compatible with expression of a more differentiated macrophage-like phenotype. Oxidized LDL also initiated aggregation of monocytes and U937 cells and stimulated adhesion of U937 cells to cultured endothelial cells. The results indicate that oxidized LDL may contribute to development of atherosclerosis by inducing adhesion of monocytes to the arterial intima and by stimulating intimal monocytes to differentiate into resident macrophages.

  20. The Bioenergetic Health Index is a sensitive measure of oxidative stress in human monocytes

    PubMed Central

    Chacko, Balu K.; Zhi, Degui; Darley-Usmar, Victor M.; Mitchell, Tanecia

    2015-01-01

    Metabolic and bioenergetic dysfunction are associated with oxidative stress and thought to be a common underlying mechanism of chronic diseases such as atherosclerosis, diabetes, and neurodegeneration. Recent findings support an emerging concept that circulating leukocytes and platelets can act as sensors or biomarkers of mitochondrial function in patients subjected to metabolic diseases. It is proposed that systemic stress-induced alterations in leukocyte bioenergetics are the consequence of several factors including reactive oxygen species. This suggests that oxidative stress mediated changes in leukocyte mitochondrial function could be used as an indicator of bioenergetic health in individuals. To test this concept, we investigated the effect of the redox cycling agent, 2,3 dimethoxynaphthoquinone (DMNQ) on the bioenergetic profiles of monocytes isolated from healthy human subjects using the extracellular flux analyzer. In addition, we tested the hypothesis that the bioenergetic health index (BHI), a single value that represents the bioenergetic health of individuals, is dynamically sensitive to oxidative stress in human monocytes. DMNQ decreased monocyte ATP-linked respiration, maximal respiration, and reserve capacity and caused an increase in proton leak and non-mitochondrial respiration compared to monocytes not treated with DMNQ. The BHI was a more sensitive indicator of the DMNQ-dependent changes in bioenergetics than any individual parameter. These data suggest that monocytes are susceptible to oxidative stress mediated by DMNQ and this can be accurately assessed by the BHI. Taken together, our findings suggest that the BHI has the potential to act as a functional biomarker of the impact of systemic oxidative stress in patients with metabolic disorders. PMID:26748041

  1. The Bioenergetic Health Index is a sensitive measure of oxidative stress in human monocytes.

    PubMed

    Chacko, Balu K; Zhi, Degui; Darley-Usmar, Victor M; Mitchell, Tanecia

    2016-08-01

    Metabolic and bioenergetic dysfunction are associated with oxidative stress and thought to be a common underlying mechanism of chronic diseases such as atherosclerosis, diabetes, and neurodegeneration. Recent findings support an emerging concept that circulating leukocytes and platelets can act as sensors or biomarkers of mitochondrial function in patients subjected to metabolic diseases. It is proposed that systemic stress-induced alterations in leukocyte bioenergetics are the consequence of several factors including reactive oxygen species. This suggests that oxidative stress mediated changes in leukocyte mitochondrial function could be used as an indicator of bioenergetic health in individuals. To test this concept, we investigated the effect of the redox cycling agent, 2,3 dimethoxynaphthoquinone (DMNQ) on the bioenergetic profiles of monocytes isolated from healthy human subjects using the extracellular flux analyzer. In addition, we tested the hypothesis that the bioenergetic health index (BHI), a single value that represents the bioenergetic health of individuals, is dynamically sensitive to oxidative stress in human monocytes. DMNQ decreased monocyte ATP-linked respiration, maximal respiration, and reserve capacity and caused an increase in proton leak and non-mitochondrial respiration compared to monocytes not treated with DMNQ. The BHI was a more sensitive indicator of the DMNQ-dependent changes in bioenergetics than any individual parameter. These data suggest that monocytes are susceptible to oxidative stress mediated by DMNQ and this can be accurately assessed by the BHI. Taken together, our findings suggest that the BHI has the potential to act as a functional biomarker of the impact of systemic oxidative stress in patients with metabolic disorders. PMID:26748041

  2. Localisation of the monocyte-binding region on human immunoglobulin G.

    PubMed

    Woof, J M; Partridge, L J; Jefferis, R; Burton, D R

    1986-03-01

    Earlier studies, which provided indirect evidence for the involvement of the C gamma 2 domain of human immunoglobulin G (IgG) in human immunoglobulin G (IgG) in human monocyte binding, have been extended to further localise the site of interaction on human IgG. A number of IgGs from several different species and fragments of human IgGs were assayed for ability to inhibit the interaction of radio-labelled human IgG and the human monocyte. By comparison of the amino-acid sequences of those IgGs found to exhibit relatively tight, intermediate or weak binding to human monocyte Fc receptors we are able to postulate a possible monocyte-binding site on human IgG. In addition, the results have implications for the applicability of monoclonal antibodies and antisera when used in the presence of human monocytes and possibly macrophages. PMID:3487030

  3. In vitro parasite-monocyte interactions in human leishmaniasis: effect of enzyme treatments on attachment.

    PubMed Central

    Wyler, D J; Suzuki, K

    1983-01-01

    Essential to the pathogenesis of leishmaniasis is the ability of Leishmania spp. to attach to mononuclear phagocyte surfaces before entering this host cell which they parasitize. We have investigated the attachment phase of infection in vitro by quantitating the percent of human peripheral blood monocytes pretreated with cytochalasin (to prevent parasite entry) to which tissue-derived L. tropica amastigotes will attach during coincubation at 37 degrees C in serum-free medium. We determined that pretreatment of parasites with trypsin, chymotrypsin, Pronase, and neuraminidase reduced attachment. In contrast, parasites treated with beta-galactosidase had an enhanced ability to attach to host cells. Treatment of monocytes with chymotrypsin and Pronase, but not with trypsin or neuraminidase, reduced attachment of untreated amastigotes. We propose that in vitro amastigote attachment under serum-free conditions depends on the interaction of protein determinants on the surface of both parasite and host cell. Images PMID:6413414

  4. RNA-sequencing analysis of high glucose-treated monocytes reveals novel transcriptome signatures and associated epigenetic profiles

    PubMed Central

    Miao, Feng; Chen, Zhuo; Zhang, Lingxiao; Wang, Jinhui; Gao, Harry; Wu, Xiwei

    2013-01-01

    We performed high throughput transcriptomic profiling with RNA sequencing (RNA-Seq) to uncover network responses in human THP-1 monocytes treated with high glucose (HG). Our data analyses revealed that interferon (IFN) signaling, pattern recognition receptors, and activated interferon regulatory factors (IRFs) were enriched among the HG-upregulated genes. Motif analysis identified an HG-responsive IRF-mediated network in which interferon-stimulated genes (ISGs) were enriched. Notably, this network showed strong overlap with a recently discovered IRF7-driven network relevant to Type 1 diabetes. We next examined if the HG-regulated genes possessed any characteristic chromatin features in the basal state by profiling 15 active and repressive chromatin marks under normal glucose conditions using chromatin immunoprecipitation linked to promoter microarrays. Composite profiles revealed higher histone H3 lysine-9-acetylation levels around the promoters of HG-upregulated genes compared with all RefSeq promoters. Interestingly, within the HG-upregulated genes, active chromatin marks were enriched not only at high CpG content promoters, but surprisingly also at low CpG content promoters. Similar results were obtained with peripheral blood monocytes exposed to HG. These new results reveal a novel mechanism by which HG can exercise IFN-α-like effects in monocytes by upregulating a set of ISGs poised for activation with multiple chromatin marks. PMID:23386205

  5. Burkholderia pseudomallei induces IL-23 production in primary human monocytes.

    PubMed

    Kulsantiwong, Panthong; Pudla, Matsayapan; Boondit, Jitrada; Wikraiphat, Chanthiwa; Dunachie, Susanna J; Chantratita, Narisara; Utaisincharoen, Pongsak

    2016-06-01

    Burkholderia pseudomallei, a gram-negative intracellular bacterium, is a causative agent of melioidosis. The bacterium has been shown to induce the innate immune response, particularly pro-inflammatory cytokine production in several of both mouse and human cell types. In the present study, we investigate host immune response in B. pseudomallei-infected primary human monocytes. We discover that wild-type B. pseudomallei is able to survive and multiply inside the primary human monocytes. In contrast, B. pseudomallei LPS mutant, a less virulent strain, is susceptible to host killing during bacterial infection. Moreover, microarray result showed that wild-type B. pseudomallei but not B. pseudomallei LPS mutant is able to activate gene expression of IL-23 as demonstrated by the up-regulation of p19 and p40 subunit expression. Consistent with gene expression analysis, the secretion of IL-23 analyzed by ELISA also showed that wild-type B. pseudomallei induces a significantly higher level of IL-23 secretion than that of B. pseudomallei LPS mutant. These results implied that IL-23 may be an important cytokine for the innate immune response during B. pseudomallei infection. The regulation of IL-23 production may drive the different host innate immune responses between patients and may relate to the severity of melioidosis. PMID:26563410

  6. Moesin Functions as a Lipopolysaccharide Receptor on Human Monocytes

    PubMed Central

    Tohme, Ziad N.; Amar, Salomon; Van Dyke, Thomas E.

    1999-01-01

    Bacterial endotoxin (lipopolysaccharide [LPS]), a glycolipid found in the outer membranes of gram-negative bacteria, induces the secretion of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), and IL-6 by monocytes/macrophages. The secretion of these biologically active compounds leads to multiple pathological conditions, such as septic shock. There is substantial evidence that chronic exposure to LPS mediates, at least in part, the tissue destruction associated with gram-negative infection. CD14, a 55-kDa protein, has been identified as an LPS receptor. In conjunction with a serum protein, LPS binding protein (LBP), LPS-CD14 interactions mediate many LPS functions in the inflammatory response. However, CD14 lacks a cytoplasmic domain, or any known signal transduction sequence motif, suggesting the existence of another cell surface domain capable of transducing signals. In this paper, we report a second, CD14-independent LPS binding site, which, based on biological activity, appears to be a functional LPS receptor. Cross-linking experiments were performed to identify LPS binding sites. Two molecules were identified: a 55-kDa protein (CD14) and a second, 78-kDa band. Sequencing of the 78-kDa protein by mass spectroscopic analysis revealed 100% homology with moesin (membrane-organizing extension spike protein). Antibody to CD14 induced partial blocking of the LPS response. However, antimoesin monoclonal antibody completely blocked the LPS-induced TNF-α response in human monocytes, without blocking CD14 binding of LPS. Irrelevant isotype controls had no effect. Additional experiments were performed to evaluate the specificity of the antimoesin blocking. Separate experiments evaluated antimoesin effects on monocyte chemotaxis, IL-1 production in response to IL-1 stimulation, and TNF-α secretion in response to Staphylococcus aureus stimulation. Antimoesin blocked only LPS-mediated events. The data suggest that moesin

  7. Inorganic arsenite alters macrophage generation from human peripheral blood monocytes

    SciTech Connect

    Sakurai, Teruaki . E-mail: sakurai@ls.toyaku.ac.jp; Ohta, Takami; Fujiwara, Kitao

    2005-03-01

    Inorganic arsenite has caused severe inflammatory chronic poisoning in humans through the consumption of contaminated well water. In this study, we examined the effects of arsenite at nanomolar concentrations on the in vitro differentiation of human macrophages from peripheral blood monocytes. While arsenite was found to induce cell death in a culture system containing macrophage colony stimulating factor (M-CSF), macrophages induced by granulocyte-macrophage CSF (GM-CSF) survived the treatment, but were morphologically, phenotypically, and functionally altered. In particular, arsenite-induced cells expressed higher levels of a major histocompatibility complex (MHC) class II antigen, HLA-DR, and CD14. They were more effective at inducing allogeneic or autologous T cell responses and responded more strongly to bacterial lipopolysaccharide (LPS) by inflammatory cytokine release as compared to cells induced by GM-CSF alone. On the other hand, arsenite-induced cells expressed lower levels of CD11b and CD54 and phagocytosed latex beads or zymosan particles less efficiently. We also demonstrated that the optimum amount of cellular reactive oxygen species (ROS) induced by nM arsenite might play an important role in this abnormal monocyte differentiation. This work may have implications in chronic arsenic poisoning because the total peripheral blood arsenic concentrations of these patients are at nM levels.

  8. Differentiation-associated toxin receptor modulation, cytokine production, and sensitivity to Shiga-like toxins in human monocytes and monocytic cell lines.

    PubMed Central

    Ramegowda, B; Tesh, V L

    1996-01-01

    Infections with Shiga toxin-producing Shigella dysenteriae type 1 or Shiga-like toxin (SLT)-producing Escherichia coli cause bloody diarrhea and are associated with an increased risk of acute renal failure and severe neurological complications. Histopathological examination of human and animal tissues suggests that the target cells for toxin action are vascular endothelial cells. Proinflammatory cytokines regulate endothelial cell membrane expression of the glycolipid globotriaosylceramide (Gb(3)) which serves as the toxin receptor, suggesting that the host response to the toxins or other bacterial products may contribute to pathogenesis by regulating target cell sensitivity to the toxins. We examined the effects of purified SLTs on human peripheral blood monocytes (PBMn) and two monocytic cell lines. Undifferentiated THP-1 cells were sensitive to SLTs. Treatment of the cells with a number of differentiation factors resulted in increased toxin resistance which was associated with decreased toxin receptor expression. U-937 cells, irrespective of maturation state, and PBMn were resistant to the toxins. U-937 cells expressed low levels of GB(3), and toxin receptor expression was not altered during differentiation. Treatment of monocytic cells with tumor necrosis factor alpha (TNF-alpha) did not markedly increase sensitivity or alter toxin receptor expression. Undifferentiated monocytic cells failed to synthesize TNF and interleukin 1beta when treated with sublethal concentrations of SLT type I (SLT-I), whereas cells treated with 12-0-tetradecanoylphorbol-13-acetate acquired the ability to produce cytokines when stimulated with SLT-I. When stimulated with SLT-I, U-937 cells produced lower levels of TNF than PBMn and THP-1 cells did. PMID:8606075

  9. Atypical Activin A and IL-10 Production Impairs Human CD16+ Monocyte Differentiation into Anti-Inflammatory Macrophages.

    PubMed

    González-Domínguez, Érika; Domínguez-Soto, Ángeles; Nieto, Concha; Flores-Sevilla, José Luis; Pacheco-Blanco, Mariana; Campos-Peña, Victoria; Meraz-Ríos, Marco A; Vega, Miguel A; Corbí, Ángel L; Sánchez-Torres, Carmen

    2016-02-01

    Human CD14(++)CD16(-) and CD14(+/lo)CD16(+) monocyte subsets comprise 85 and 15% of blood monocytes, respectively, and are thought to represent distinct stages in the monocyte differentiation pathway. However, the differentiation fates of both monocyte subsets along the macrophage (Mϕ) lineage have not yet been elucidated. We have now evaluated the potential of CD14(++) CD16(-) and CD16(+) monocytes to differentiate and to be primed toward pro- or anti-inflammatory Mϕs upon culture with GM-CSF or M-CSF, respectively (subsequently referred to as GM14, M14, GM16, or M16). Whereas GM16 and GM14 were phenotypic and functionally analogous, M16 displayed a more proinflammatory profile than did M14. Transcriptomic analyses evidenced that genes associated with M-CSF-driven Mϕ differentiation (including FOLR2, IL10, IGF1, and SERPINB2) are underrepresented in M16 with respect to M14. The preferential proinflammatory skewing of M16 relative to M14 was found to be mediated by the secretion of activin A and the low levels of IL-10 produced by M16. In fact, activin A receptor blockade during the M-CSF-driven differentiation of CD16(+) monocytes, or addition of IL-10-containing M14-conditioned medium, significantly enhanced their expression of anti-inflammatory-associated molecules while impairing their acquisition of proinflammatory-related markers. Thus, we propose that M-CSF drives CD14(++)CD16- monocyte differentiation into bona fide anti-inflammatory Mϕs in a self-autonomous manner, whereas M-CSF-treated CD16(+) monocytes generate Mϕs with a skewed proinflammatory profile by virtue of their high activin A expression unless additional anti-inflammatory stimuli such as IL-10 are provided. PMID:26729812

  10. CD13 mediates phagocytosis in human monocytic cells.

    PubMed

    Licona-Limón, Ileana; Garay-Canales, Claudia A; Muñoz-Paleta, Ofelia; Ortega, Enrique

    2015-07-01

    CD13 is a membrane-bound ectopeptidase, highly expressed on monocytes, macrophages, and dendritic cells. CD13 is involved in diverse functions, including degradation of peptide mediators, cellular adhesion, migration, viral endocytosis, signaling, and positive modulation of phagocytosis mediated by FcγRs and other phagocytic receptors. In this work, we explored whether besides acting as an accessory receptor, CD13 by itself is a primary phagocytic receptor. We found that hCD13 mediates efficient phagocytosis of large particles (erythrocytes) modified so as to interact with the cell only through CD13 in human macrophages and THP-1 monocytic cells. The extent of this phagocytosis is comparable with the phagocytosis mediated through the canonical phagocytic receptor FcγRI. Furthermore, we demonstrated that hCD13 expression in the nonphagocytic cell line HEK293 is sufficient to enable these cells to internalize particles bound through hCD13. CD13-mediated phagocytosis is independent of other phagocytic receptors, as it occurs in the absence of FcγRs, CR3, and most phagocytic receptors. Phagocytosis through CD13 is independent of its enzymatic activity but is dependent on actin rearrangement and activation of PI3K and is partially dependent on Syk activation. Moreover, the cross-linking of CD13 with antibodies rapidly induced pSyk in human macrophages. Finally, we observed that antibody-mediated cross-linking of hCD13, expressed in the murine macrophage-like J774 cell line, induces production of ROS. These results demonstrate that CD13 is a fully competent phagocytic receptor capable of mediating internalization of large particles. PMID:25934926

  11. Human monocytes and macrophages differ in their mechanisms of adaptation to hypoxia

    PubMed Central

    2012-01-01

    Introduction Inflammatory arthritis is a progressive disease with chronic inflammation of joints, which is mainly characterized by the infiltration of immune cells and synovial hyperproliferation. Monocytes migrate towards inflamed areas and differentiate into macrophages. In inflamed tissues, much lower oxygen levels (hypoxia) are present in comparison to the peripheral blood. Hence, a metabolic adaptation process must take place. Other studies suggest that Hypoxia Inducible Factor 1-alpha (HIF-1α) may regulate this process, but the mechanism involved for human monocytes is not yet clear. To address this issue, we analyzed the expression and function of HIF-1α in monocytes and macrophages, but also considered alternative pathways involving nuclear factor of kappa light polypeptide gene enhancer in B-cells (NFκB). Methods Isolated human CD14+ monocytes were incubated under normoxia and hypoxia conditions with or without phorbol 12-myristate 13-acetate (PMA) stimulation, respectively. Nuclear and cytosolic fractions were prepared in order to detect HIF-1α and NFκB by immunoblot. For the experiments with macrophages, primary human monocytes were differentiated into human monocyte derived macrophages (hMDM) using human macrophage colony-stimulating factor (hM-CSF). The effects of normoxia and hypoxia on gene expression were compared between monocytes and hMDMs using quantitative PCR (quantitative polymerase chain reaction). Results We demonstrate, using primary human monocytes and hMDM, that the localization of transcription factor HIF-1α during the differentiation process is shifted from the cytosol (in monocytes) into the nucleus (in macrophages), apparently as an adaptation to a low oxygen environment. For this localization change, protein kinase C alpha/beta 1 (PKC-α/β1 ) plays an important role. In monocytes, it is NFκB1, and not HIF-1α, which is of central importance for the expression of hypoxia-adjusted genes. Conclusions These data demonstrate that

  12. Peroxidatic activity distinct from myeloperoxidase in human monocytes cultured in vitro and in alveolar macrophages.

    PubMed

    Breton-Gorius, J; Vildé, J L; Guichard, J; Vainchenker, W; Basset, F

    1982-01-01

    Human monocytes develop a peroxidatic activity (PA) in rough endoplasmic reticulum (RER) after adherence or after culture in semi-solid medium. This enzyme activity disappears after three days of culture in the majority of macrophages derived from adult monocytes but persists for one week in macrophages derived from neonatal monocytes. The PA is due to an enzyme distinct from myeloperoxidase (MPO), since monocytes from a patient with MPO deficiency develop the same PA as that of normal monocytes after adherence. By its localization and other characteristics, PA of adherent monocytes resembles that of rodent macrophages. We therefore investigated whether human alveolar macrophages exhibit PA, using a sensitive cytochemical method which prevents inhibition by aldehyde in adherent monocytes. In various pathological cases, four types of macrophages could be identified: the majority were peroxidase-negative, a small percentage was of exudate type exhibiting a PA in granules as blood monocytes, while few macrophages were intermediate, possessing only PA in RER i.e. of type resident and a smaller proportion had PA in RER and in granules i.e. exudate-resident macrophages. These findings demonstrate that human macrophages and adherent monocytes may exhibit PA in RER as has been reported for rodent macrophages. The true nature and function of the enzyme responsible for this PA, which is distinct from MPO, remains unknown, but some arguments seem to suggest its role in prostaglandin synthesis. PMID:6283838

  13. Expression and regulation of Schlafen (SLFN) family members in primary human monocytes, monocyte-derived dendritic cells and T cells

    PubMed Central

    Puck, Alexander; Aigner, Regina; Modak, Madhura; Cejka, Petra; Blaas, Dieter; Stöckl, Johannes

    2015-01-01

    Schlafen (SLFN/Slfn) family members have been investigated for their involvement in fundamental cellular processes including growth regulation, differentiation and control of viral replication. However, most research has been focused on the characterization of Slfns within the murine system or in human cell lines. Since little is known about SLFNs in primary human immune cells, we set out to analyze the expression and regulation of the six human SLFN genes in monocytes, monocyte-derived dendritic cells (moDCs) and T cells. Comparison of SLFN gene expression across these three cell types showed high mRNA expression of SLFN11 in monocytes and moDCs and high SLFN5 expression in T cells, indicating functional importance within these cell types. Differentiation of monocytes to moDCs leads to the gradual upregulation of SLFN12L and SLFN13 while SLFN12 levels were decreased by differentiation stimuli. Stimulation of moDCs via human rhinovirus, lipopolysaccharide, or IFN-α lead to strong upregulation of SLFN gene expression, while peptidoglycan poorly stimulated regulation of both SLFNs and the classical interferon-stimulated gene MxA. T cell activation was found to downregulate the expression of SLFN5, SLFN12 and SLFN12L, which was reversible upon addition of exogenous IFN-α. In conclusion, we demonstrate, that SLFN gene upregulation is mainly dependent on autocrine type I interferon signaling in primary human immune cells. Rapid decrease of SLFN expression levels following T cell receptor stimulation indicates a role of SLFNs in the regulation of human T cell quiescence. PMID:26623250

  14. NFκB2/p100 is a key factor for endotoxin tolerance in human monocytes: a demonstration using primary human monocytes from patients with sepsis.

    PubMed

    Cubillos-Zapata, Carolina; Hernández-Jiménez, Enrique; Toledano, Víctor; Esteban-Burgos, Laura; Fernández-Ruíz, Irene; Gómez-Piña, Vanesa; Del Fresno, Carlos; Siliceo, María; Prieto-Chinchiña, Patricia; Pérez de Diego, Rebeca; Boscá, Lisardo; Fresno, Manuel; Arnalich, Francisco; López-Collazo, Eduardo

    2014-10-15

    Endotoxin tolerance (ET) is a state of reduced responsiveness to endotoxin stimulation after a primary bacterial insult. This phenomenon has been described in several pathologies, including sepsis, in which an endotoxin challenge results in reduced cytokine production. In this study, we show that the NFκ L chain enhancer of activated B cells 2 (NFκB2)/p100 was overexpressed and accumulated in a well-established in vitro human monocyte model of ET. The p100 accumulation in these cells inversely correlated with the inflammatory response after LPS stimulation. Knocking down NFκB2/p100 using small interfering RNA in human monocytes further indicated that p100 expression is a crucial factor in the progression of ET. The monocytes derived from patients with sepsis had high levels of p100, and a downregulation of NFκB2/p100 in these septic monocytes reversed their ET status. PMID:25225662

  15. Nonadherent cultures of human monocytes kill Mycobacterium smegmatis, but adherent cultures do not.

    PubMed Central

    Barker, K; Fan, H; Carroll, C; Kaplan, G; Barker, J; Hellmann, W; Cohn, Z A

    1996-01-01

    Human peripheral blood monocytes are permissive for the growth of Mycobacterium tuberculosis, but the fate of nonpathogenic Mycobacterium smegmatis in these cells is not known. Since M. smegmatis may be used as a host with which to express and screen for M. tuberculosis genes needed for survival in monocytes, we determined whether human peripheral blood monocytes could restrict the growth of Mycobacterium smegmatis. Adherent human peripheral blood monocytes were permissive for the growth of M. smegmatis, as measured by ex vivo [3H]uracil uptake. However, human peripheral blood monocytes which were cultured nonadherently in Teflon wells were able to restrict the growth of M. smegmatis while remaining permissive for the growth of M. tuberculosis H37Ra. The loss of viability of M. smegmatis in nonadherent cells was correlated with an increase in nonspacious phagocytic vacuoles. The killing of M. smegmatis was not blocked by NG-monomethyl-L-arginine, suggesting that it was not due to the production of reactive nitrogen intermediates. Incubation of the monocytes for 1 to 7 days before infection had no effect on the fate of M. smegmatis, suggesting that adherence versus nonadherence, and not differentiation, was the key determinant for the difference in functional ability. Nonadherent human peripheral blood monocytes may be a more appropriate model than adherent cells for the study of factors employed by bacterial to survive within monocytes and for selection screening of bacterial genes needed for intracellular survival. PMID:8550187

  16. Restricted dendritic cell and monocyte progenitors in human cord blood and bone marrow

    PubMed Central

    Lee, Jaeyop; Breton, Gaëlle; Oliveira, Thiago Yukio Kikuchi; Zhou, Yu Jerry; Aljoufi, Arafat; Puhr, Sarah; Cameron, Mark J.; Sékaly, Rafick-Pierre

    2015-01-01

    In mice, two restricted dendritic cell (DC) progenitors, macrophage/dendritic progenitors (MDPs) and common dendritic progenitors (CDPs), demonstrate increasing commitment to the DC lineage, as they sequentially lose granulocyte and monocyte potential, respectively. Identifying these progenitors has enabled us to understand the role of DCs and monocytes in immunity and tolerance in mice. In humans, however, restricted monocyte and DC progenitors remain unknown. Progress in studying human DC development has been hampered by lack of an in vitro culture system that recapitulates in vivo DC hematopoiesis. Here we report a culture system that supports development of CD34+ hematopoietic stem cell progenitors into the three major human DC subsets, monocytes, granulocytes, and NK and B cells. Using this culture system, we defined the pathway for human DC development and revealed the sequential origin of human DCs from increasingly restricted progenitors: a human granulocyte-monocyte-DC progenitor (hGMDP) that develops into a human monocyte-dendritic progenitor (hMDP), which in turn develops into monocytes, and a human CDP (hCDP) that is restricted to produce the three major DC subsets. The phenotype of the DC progenitors partially overlaps with granulocyte-macrophage progenitors (GMPs). These progenitors reside in human cord blood and bone marrow but not in the blood or lymphoid tissues. PMID:25687283

  17. Cerium dioxide nanoparticles do not modulate the lipopolysaccharide-induced inflammatory response in human monocytes

    PubMed Central

    Hussain, Salik; Al-Nsour, Faris; Rice, Annette B; Marshburn, Jamie; Ji, Zhaoxia; Zink, Jeffery I; Yingling, Brenda; Walker, Nigel J; Garantziotis, Stavros

    2012-01-01

    Background Cerium dioxide (CeO2) nanoparticles have potential therapeutic applications and are widely used for industrial purposes. However, the effects of these nanoparticles on primary human cells are largely unknown. The ability of nanoparticles to exacerbate pre-existing inflammatory disorders is not well documented for engineered nanoparticles, and is certainly lacking for CeO2 nanoparticles. We investigated the inflammation-modulating effects of CeO2 nanoparticles at noncytotoxic concentrations in human peripheral blood monocytes. Methods CD14+ cells were isolated from peripheral blood samples of human volunteers. Cells were exposed to either 0.5 or 1 μg/mL of CeO2 nanoparticles over a period of 24 or 48 hours with or without lipopolysaccharide (10 ng/mL) prestimulation. Modulation of the inflammatory response was studied by measuring secreted tumor necrosis factor-alpha, interleukin-1beta, macrophage chemotactic protein-1, interferon-gamma, and interferon gamma-induced protein 10. Results CeO2 nanoparticle suspensions were thoroughly characterized using dynamic light scattering analysis (194 nm hydrodynamic diameter), zeta potential analysis (−14 mV), and transmission electron microscopy (irregular-shaped particles). Transmission electron microscopy of CD14+ cells exposed to CeO2 nanoparticles revealed that these nanoparticles were efficiently internalized by monocytes and were found either in vesicles or free in the cytoplasm. However, no significant differences in secreted cytokine profiles were observed between CeO2 nanoparticle-treated cells and control cells at noncytotoxic doses. No significant effects of CeO2 nanoparticle exposure subsequent to lipopolysaccharide priming was observed on cytokine secretion. Moreover, no significant difference in lipopolysaccharide-induced cytokine production was observed after exposure to CeO2 nanoparticles followed by lipopolysaccharide exposure. Conclusion CeO2 nanoparticles at noncytotoxic concentrations neither

  18. Interactions between human monocytes and tumour cells. Monocytes can either enhance or inhibit the growth and survival of K562 cells.

    PubMed Central

    Davies, B.; Edwards, S. W.

    1992-01-01

    Human bloodstream monocytes can kill cultured tumour cells (K562), as assessed by specific release of 51Cr from the targets and by inhibition of 3H-thymidine incorporation. Confluent monolayers of monocytes were required for maximal cytotoxicity, and the density of the K562 cells was also an important factor. For example, when K562 cells were seeded at high cell densities, they were killed during incubation with monocytes, but when seeded at low cell densities their growth and survival was enhanced during culture with monocytes. The factor(s) which promoted the survival and division of low density K562 cultures was endogenously secreted from monocytes as it was present in monocyte-conditioned medium, whereas the cytotoxic factor(s) were only expressed during co-culture of monocytes with K562 cells. Conditioned medium from HL 60, U-937, HeLa and K562 could also enhance the growth and survival of low density K562 cultures, and a similar effect was also observed upon the addition of catalase and superoxide dismutase to such cultures. Thus, the monocyte:target ratio is important in determining whether monocytes exhibit cytotoxic or growth-promoting effects and hence tumour-derived or monocyte-derived reactive oxidant species may play a role in tumour cell cycle regulation. PMID:1520583

  19. Exosomes derived from alcohol-treated hepatocytes horizontally transfer liver specific miRNA-122 and sensitize monocytes to LPS

    PubMed Central

    Momen-Heravi, Fatemeh; Bala, Shashi; Kodys, Karen; Szabo, Gyongyi

    2015-01-01

    Hepatocyte damage and inflammation in monocytes/macrophages are central to the pathogenesis of alcoholic hepatitis (AH). MicroRNAs (miRNAs) regulate all of these processes. MiRNA-122 is abundantly expressed in hepatocytes while monocytes/macrophages have low levels. The role of exosomes in AH and possible cross talk between hepatocyte-derived exosomes and immune cells is not explored yet. Here, we show that the number of exosomes significantly increases in the sera of healthy individuals after alcohol binge drinking and in mice after binge or chronic alcohol consumption. Exosomes isolated from sera after alcohol consumption or from in vitro ethanol-treated hepatocytes contained miRNA-122. Exosomes derived from ethanol-treated Huh7.5 cells were taken up by the recipients THP1 monocytes and horizontally transferred a mature form of liver-specific miRNA-122. In vivo, liver mononuclear cells and Kupffer cells from alcohol-fed mice had increased miRNA-122 levels. In monocytes, miRNA-122 transferred via exosomes inhibited the HO-1 pathway and sensitized to LPS stimulation and increased levels of pro-inflammatory cytokines. Finally, inflammatory effects of exosomes from ethanol-treated hepatocytes were prevented by using RNA interference via exosome-mediated delivery of a miRNA-122 inhibitor. These results demonstrate that first, exosomes mediate communication between hepatocytes and monocytes/macrophages and second, hepatocyte-derived miRNA-122 can reprogram monocytes inducing sensitization to LPS. PMID:25973575

  20. Exosomes derived from alcohol-treated hepatocytes horizontally transfer liver specific miRNA-122 and sensitize monocytes to LPS.

    PubMed

    Momen-Heravi, Fatemeh; Bala, Shashi; Kodys, Karen; Szabo, Gyongyi

    2015-01-01

    Hepatocyte damage and inflammation in monocytes/macrophages are central to the pathogenesis of alcoholic hepatitis (AH). MicroRNAs (miRNAs) regulate all of these processes. MiRNA-122 is abundantly expressed in hepatocytes while monocytes/macrophages have low levels. The role of exosomes in AH and possible cross talk between hepatocyte-derived exosomes and immune cells is not explored yet. Here, we show that the number of exosomes significantly increases in the sera of healthy individuals after alcohol binge drinking and in mice after binge or chronic alcohol consumption. Exosomes isolated from sera after alcohol consumption or from in vitro ethanol-treated hepatocytes contained miRNA-122. Exosomes derived from ethanol-treated Huh7.5 cells were taken up by the recipients THP1 monocytes and horizontally transferred a mature form of liver-specific miRNA-122. In vivo, liver mononuclear cells and Kupffer cells from alcohol-fed mice had increased miRNA-122 levels. In monocytes, miRNA-122 transferred via exosomes inhibited the HO-1 pathway and sensitized to LPS stimulation and increased levels of pro-inflammatory cytokines. Finally, inflammatory effects of exosomes from ethanol-treated hepatocytes were prevented by using RNA interference via exosome-mediated delivery of a miRNA-122 inhibitor. These results demonstrate that first, exosomes mediate communication between hepatocytes and monocytes/macrophages and second, hepatocyte-derived miRNA-122 can reprogram monocytes inducing sensitization to LPS. PMID:25973575

  1. Apoptosis of human monocytes and macrophages by Mycobacterium avium sonicate.

    PubMed Central

    Hayashi, T; Catanzaro, A; Rao, S P

    1997-01-01

    Mycobacterium avium is an intracellular organism which multiplies predominantly within human macrophages. This organism has previously been shown to induce apoptosis in human macrophages. With a view to identifying M. avium components that induce cell death in infected host cells, sonicated extracts of M. avium as well as individual components isolated from the M. avium sonicate were tested in various assays with a human monocytic cell line (THP-1). THP-1 cells incubated with M. avium sonicate showed significantly reduced viability after a 2-day exposure compared to control cells incubated with media alone. This effect was dose dependent, with only 6.6% +/- 5.2% and 48.8% +/- 10.3% of the cells being viable by trypan blue exclusion at 600 and 300 microg/ml, respectively. Control cells, on the other hand, exhibited a viability of 98.8% +/- 1.0%. In addition, an 80% ammonium sulfate fraction of the M. avium sonicate and the previously characterized 68-kDa protein were found to have similar effects on THP-1 cells. In both cases, the reduction in viability was due to apoptosis characterized by chromatin condensation, DNA fragmentation by agarose gel electrophoresis, or terminal deoxynucleotidyl transferase-mediated d-UTP nick end labeling (TUNEL) and release of nuclear matrix protein (NMP) into the culture medium. M. avium sonicate-induced apoptosis of THP-1 cells was completely inhibited by the commonly used antioxidants pyrrolidinedithiocarbamate (PDTC) and butylated hydroxyanisole (BHA), indicating that the generation of free oxygen radicals may be responsible for inducing cell death. M. avium sonicate was found to induce apoptosis of monocyte-derived macrophages (MDMs) as well. This effect was not reversed in the presence of PDTC and was not accompanied with DNA fragmentation when determined by agarose gel electrophoresis, as seen in the case of THP-1 cells. However, these MDMs were found to contain fragmented DNA by TUNEL. These findings suggest that the mechanism

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

    SciTech Connect

    Wu, Hsin-Ying; Chang, An-Chi; Wang, Chia-Chi; Kuo, Fu-Hua; Lee, Chi-Ya; Liu, Der-Zen; Jan, Tong-Rong

    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. The 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.

  3. Oligonol, a lychee fruit-derived low-molecular form of polyphenol mixture, suppresses inflammatory cytokine production from human monocytes.

    PubMed

    Lee, Naeun; Shin, Min Sun; Kang, Youna; Park, Kieyoung; Maeda, Takahiro; Nishioka, Hiroshi; Fujii, Hajime; Kang, Insoo

    2016-06-01

    Monocytes produce high levels of inflammatory cytokines including IL-6 and TNF-α that are involved in autoimmunity, inflammatory diseases, cardiovascular disease and obesity. Therapies targeting IL-6 and TNF-α have been utilized in treating chronic inflammatory diseases. Oligonol is a lychee fruit-derived low-molecular form of polyphenol mixture, typically catechin-type monomers and oligomers of proanthocyanidins, which are produced by an oligomerization process. Although previous studies reported anti-inflammatory properties of Oligonol, it is unknown whether and how Oligonol suppresses IL-6 and TNF-α production in human monocytes. The results of our study demonstrate that Oligonol (25μg/ml) decreases the production of IL-6 and TNF-α from human primary monocytes as measured by flow cytometry and ELISA. Such an anti-cytokine effect was likely mediated by the suppression of NF-κB activation without inducing cell death. Our findings raise the possibility of exploring the benefits of Oligonol in controlling inflammatory conditions, especially those associated with monocytes, in humans. PMID:27079270

  4. Actinobacillus actinomycetemcomitans induces apoptosis in human monocytic THP-1 cells.

    PubMed

    Kato, Satsuki; Sugimura, Norihiko; Nakashima, Keisuke; Nishihara, Tatsuji; Kowashi, Yusuke

    2005-03-01

    It has previously been reported that the murine macrophage cell line J774.1 and the human oral epithelial cell line KB undergo apoptosis as a result of Actinobacillus actinomycetemcomitans infection. Recent studies have demonstrated that apoptosis regulation is modulated by multiple phosphorylation of several different protein kinases, including the major subtypes of the mitogen-activated protein kinase (MAPK) family. The MAPK family promotes cell survival and/or proliferation in response to growth factor stimulation, or apoptosis in response to various stress stimuli. The primary objective of the present investigation was to clarify whether human immune cells undergo apoptosis following A. actinomycetemcomitans infection and, if so, to establish the involvement of the MAPK family. Human monocytic THP-1 cells were infected with A. actinomycetemcomitans in microtubes. Lactate dehydrogenase release into the culture supernatant and DNA fragmentation in the cells were monitored. DNA fragmentation was also identified by agarose gel electrophoresis. Cell death following A. actinomycetemcomitans infection occurred by apoptosis, shown by an increase in the proportion of fragmented DNA and the typical ladder pattern of DNA fragmentation indicative of apoptosis. Furthermore, p38 MAPK activity and tumour necrosis factor alpha (TNF-alpha) levels increased following A. actinomycetemcomitans infection. In contrast, cell death and TNF-alpha levels in infected cells decreased upon addition of a p38 inhibitor or an anti-TNF-alpha antibody. However, exogenous TNF-alpha could not induce apoptosis in uninfected THP-1 cells. Interestingly, p38 MAPK activity diminished in the presence of anti-TNF-alpha antibody. These findings indicated that A. actinomycetemcomitans infection induces apoptosis in THP-1 cells and that p38 MAPK activity is directly involved in apoptosis. TNF-alpha may play an indirect role in apoptosis via enhanced p38 MAPK activity. A. actinomycetemcomitans

  5. Quantitative Proteomics Reveals a Role for Epigenetic Reprogramming During Human Monocyte Differentiation*

    PubMed Central

    Nicholas, Dequina; Tang, Hui; Zhang, Qiongyi; Rudra, Jai; Xu, Feng; Langridge, William; Zhang, Kangling

    2015-01-01

    The differentiation of monocytes into macrophages and dendritic cells involves mechanisms for activation of the innate immune system in response to inflammatory stimuli, such as pathogen infection and environmental cues. Epigenetic reprogramming is thought to play an important role during monocyte differentiation. Complementary to cell surface markers, the characterization of monocytic cell lineages by mass spectrometry based protein/histone expression profiling opens a new avenue for studying immune cell differentiation. Here, we report the application of mass spectrometry and bioinformatics to identify changes in human monocytes during their differentiation into macrophages and dendritic cells. Our data show that linker histone H1 proteins are significantly down-regulated during monocyte differentiation. Although highly enriched H3K9-methyl/S10-phos/K14-acetyl tri-modification forms of histone H3 were identified in monocytes and macrophages, they were dramatically reduced in dendritic cells. In contrast, histone H4 K16 acetylation was found to be markedly higher in dendritic cells than in monocytes and macrophages. We also found that global hyperacetylation generated by the nonspecific histone deacetylase HDAC inhibitor Apicidin induces monocyte differentiation. Together, our data suggest that specific regulation of inter- and intra-histone modifications including H3 K9 methylation, H3 S10 phosphorylation, H3 K14 acetylation, and H4 K16 acetylation must occur in concert with chromatin remodeling by linker histones for cell cycle progression and differentiation of human myeloid cells into macrophages and dendritic cells. PMID:25316709

  6. Quantitative proteomics reveals a role for epigenetic reprogramming during human monocyte differentiation.

    PubMed

    Nicholas, Dequina; Tang, Hui; Zhang, Qiongyi; Rudra, Jai; Xu, Feng; Langridge, William; Zhang, Kangling

    2015-01-01

    The differentiation of monocytes into macrophages and dendritic cells involves mechanisms for activation of the innate immune system in response to inflammatory stimuli, such as pathogen infection and environmental cues. Epigenetic reprogramming is thought to play an important role during monocyte differentiation. Complementary to cell surface markers, the characterization of monocytic cell lineages by mass spectrometry based protein/histone expression profiling opens a new avenue for studying immune cell differentiation. Here, we report the application of mass spectrometry and bioinformatics to identify changes in human monocytes during their differentiation into macrophages and dendritic cells. Our data show that linker histone H1 proteins are significantly down-regulated during monocyte differentiation. Although highly enriched H3K9-methyl/S10-phos/K14-acetyl tri-modification forms of histone H3 were identified in monocytes and macrophages, they were dramatically reduced in dendritic cells. In contrast, histone H4 K16 acetylation was found to be markedly higher in dendritic cells than in monocytes and macrophages. We also found that global hyperacetylation generated by the nonspecific histone deacetylase HDAC inhibitor Apicidin induces monocyte differentiation. Together, our data suggest that specific regulation of inter- and intra-histone modifications including H3 K9 methylation, H3 S10 phosphorylation, H3 K14 acetylation, and H4 K16 acetylation must occur in concert with chromatin remodeling by linker histones for cell cycle progression and differentiation of human myeloid cells into macrophages and dendritic cells. PMID:25316709

  7. Human monocyte CD14 is upregulated by lipopolysaccharide.

    PubMed Central

    Landmann, R; Knopf, H P; Link, S; Sansano, S; Schumann, R; Zimmerli, W

    1996-01-01

    Membrane CD14 is involved in lipopolysaccharide (LPS)-induced monocyte activation; it binds LPS, and antibodies against CD14 block the effects of low-dose LPS. It is unknown how LPS regulates its own receptor CD14 in vitro. Therefore, we investigated the effects of LPS on CD14 mRNA and membrane and soluble CD14 (mCD14 and sCD14, respectively) in human monocytes and macrophages. No changes were observed during the first 3 h of LPS stimulation. After 6 to 15 h, LPS weakly reduced CD14 mRNA and mCD14 and transiently enhanced sCD14 release. A 2-day incubation with LPS caused increases in the levels of CD14 mRNA (2-fold), mCD14 (2-fold), sCD14 (1.5-fold), and LPS-fluorescein isothiocyanate binding (1.5-fold); a 5-h incubation with LPS was sufficient to induce the late effects on mCD14 and sCD14. The maximal effect on mCD14 and sCD14 was reached with > or = 1 ng of LPS per ml; the proportional distribution of the two sCD14 isoforms was not modified by LPS. Besides rough and smooth LPS, lipid A, heat-killed Escherichia coli, lipoteichoic acid, and Staphylococcus aureus cell wall extract (10 micrograms/ml) caused similar increases of mCD14. The LPS effect was blocked by polymyxin B but not by anti-tumor necrosis factor alpha, anti-interleukin-6, anti-gamma interferon, and anti-LPS-binding protein. LPS-induced tumor necrosis factor alpha production was abolished after a second 4-h challenge. In contrast, the LPS-induced increases CD14 mRNA, mCD14, and sCD14 were stronger and appeared earlier after a second LPS challenge. In conclusion, CD14 is transcriptionally upregulated by LPS and other bacterial cell wall constituents. PMID:8613389

  8. High-Affinity Fc Receptor Expression Indicates Relative Immaturity in Human Monocytes.

    PubMed

    Clanchy, Felix I L

    2016-05-01

    Within monocyte heterogeneity, subsets represent discrete, well-characterized phenotypes. Although many studies have highlighted differences between subsets, there is evidence that subpopulations represent contiguous stages in a maturational series. As CD14(hi)CD64(hi) monocytes have higher proliferative potential than CD14(hi)CD64(lo) monocytes, the surface marker profile on 4 subsets defined by CD14 and CD64 was measured. The profiles were compared to that of subsets defined by the high-affinity IgE receptor (FcɛRIα), CD16, and CD14; further differences in size, granularity, and buoyancy were measured in subsets delineated by these markers. There was a positive correlation between proliferative monocyte (PM) prevalence and CD64 expression on the classical monocyte subset, and also between PM prevalence and circulating FcɛRIα(+) monocytes. The expression of CD64, the high-affinity IgG receptor, on canonical human monocyte subsets was determined before and after short-term culture, and in response to interleukin (IL)-6, IL-10, macrophage colony-stimulating factor, granulocyte/macrophage colony-stimulating factor and interferon-γ; the influence of these cytokines on monocyte subset transition was also measured. The loss of FcɛRIα expression preceded an increase in CD16 expression in whole blood cultures. These data indicate that high-affinity Fc receptors are expressed on less mature monocytes and that FcɛRIα(+) monocytes are developmentally antecedent to the canonical classical and intermediate monocyte subsets. PMID:26714112

  9. Beta 1,4-oligoglucosides inhibit the binding of Aspergillus fumigatus conidia to human monocytes.

    PubMed

    Kan, V L; Bennett, J E

    1991-05-01

    The binding of Aspergillus fumigatus conidia to human monocytes is mediated by a barley beta-glucan-inhibitable receptor. The simplest linkages in this glucan are present in the disaccharides laminaribiose (beta 1,3) and cellobiose (beta 1,4). Although laminaribiose gave strong inhibition of conidial binding to monocytes, cellobiose and oligosaccharides with beta 1,4-linked glucose residues were more potent as specific inhibitors of this binding over similar concentrations. Increasing the number of beta 1,4-linked glucose residues led to greater inhibition of conidial binding by human monocytes. PMID:2019764

  10. Cyclic dinucleotides modulate human T-cell response through monocyte cell death.

    PubMed

    Tosolini, Marie; Pont, Frédéric; Verhoeyen, Els; Fournié, Jean-Jacques

    2015-12-01

    Cyclic dinucleotides, a class of microbial messengers, have been recently identified in bacteria, but their activity in humans remains largely unknown. Here, we have studied the function of cyclic dinucleotides in humans. We found that c-di-AMP and cGAMP, two adenosine-based cyclic dinucleotides, activated T lymphocytes in an unusual manner through monocyte cell death. c-di-AMP and cGAMP induced the selective apoptosis of human monocytes, and T lymphocytes were activated by the direct contact with these dying monocytes. The ensuing T-cell response comprised cell-cycle exit, phenotypic maturation into effector memory cells and proliferation arrest, but not cell death. This quiescence was transient since T cells remained fully responsive to further restimulation. Together, our results depict a novel activation pattern for human T lymphocytes: a transient quiescence induced by c-di-AMP- or cGAMP-primed apoptotic monocytes. PMID:26460927

  11. 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

  12. p38 mitogen-activated protein kinase mediates IL-8 induction by the ribotoxin deoxynivalenol in human monocytes

    SciTech Connect

    Islam, Zahidul; Gray, Jennifer S.; Pestka, James J. . E-mail: pestka@msu.edu

    2006-06-15

    The effects of the ribotoxic trichothecene deoxynivalenol (DON) on mitogen-activated protein kinase (MAPK)-mediated IL-8 expression were investigated in cloned human monocytes and peripheral blood mononuclear cells (PBMC). DON (250 to 1000 ng/ml) induced both IL-8 mRNA and IL-8 heteronuclear RNA (hnRNA), an indicator of IL-8 transcription, in the human U937 monocytic cell line in a concentration-dependent manner. Expression of IL-8 hnRNA, mRNA and protein correlated with p38 phosphorylation and was completely abrogated by the p38 MAPK inhibitor SB203580. DON at 500 ng/ml similarly induced p38-dependent IL-8 protein and mRNA expression in PBMC cultures from healthy volunteers. Significantly increased IL-6 and IL-1{beta} intracellular protein and mRNA expression was also observed in PBMC treated with DON (500 ng/ml) which were also partially p38-dependent. Flow cytometry of PBMC revealed that DON-induced p38 phosphorylation varied among individuals relative to both threshold toxin concentrations (25-100 ng/ml) and relative increases in percentages of phospho-p38{sup +} cells. DON-induced p38 activation occurred exclusively in the CD14{sup +} monocyte population. DON was devoid of agonist activity for human Toll-like receptors 2, 3, 4, 5, 7, 8 and 9. However, two other ribotoxins, emetine and anisomycin, induced p38 phosphorylation in PBMC similarly to DON. Taken together, these data suggest that (1) p38 activation was required for induction of IL-8 and proinflammatory gene expression in the monocyte and (2) DON induced p38 activation in human monocytes via the ribotoxic stress response.

  13. Ginkgolide B Inhibits JAM-A, Cx43, and VE-Cadherin Expression and Reduces Monocyte Transmigration in Oxidized LDL-Stimulated Human Umbilical Vein Endothelial Cells

    PubMed Central

    Liu, Xueqing; Sun, Wenjia; Zhao, Yanyang; Chen, Beidong; Wu, Wei; Bao, Li; Qi, Ruomei

    2015-01-01

    Aim. To investigate the effect of ginkgolide B on junction proteins and the reduction of monocyte migration in oxidized low-density lipoprotein- (ox-LDL-) treated endothelial cells. Methods. Human umbilical vein endothelial cells (HUVECs) were used in the present study. Immunofluorescence and Western blot were performed to determine the expression of junctional adhesion molecule-A (JAM-A), connexin 43 (Cx43), and vascular endothelial cadherin (VE-cadherin). Monocyte migration was detected by the Transwell assay. Results. ox-LDL stimulation increased JAM-A expression by 35%, Cx43 expression by 24%, and VE-cadherin expression by 37% in HUVECs. Ginkgolide B (0.2, 0.4, and 0.6 mg/mL) dose-dependently abolished the expression of these junction proteins. The monocyte transmigration experiments showed that the level of monocyte migration was sixfold higher in the ox-LDL-treated group than in the control group. Ginkgolide B (0.6 mg/mL) nearly completely abolished monocyte migration. Both ginkgolide B and LY294002 suppressed Akt phosphorylation and the expression of these junction proteins in ox-LDL-treated endothelial cells. These results suggest that the ginkgolide B-induced inhibition of junction protein expression is associated with blockade of the PI3K/Akt pathway. Conclusion. Ginkgolide B suppressed junction protein expression and reduced monocyte transmigration that was induced by ox-LDL. Ginkgolide B may improve vascular permeability in atherosclerosis. PMID:26246869

  14. Differences in PGE2 Production between Primary Human Monocytes and Differentiated Macrophages: Role of IL-1β and TRIF/IRF3

    PubMed Central

    Romantseva, Tatiana; Golding, Hana; Zaitseva, Marina

    2014-01-01

    Prostaglandin E2 (PGE2) is induced in vivo by bacterial products including TLR agonists. To determine whether PGE2 is induced directly or via IL-1β, human monocytes and macrophages were cultured with LPS or with Pam3CSK4 in presence of caspase-1 inhibitor, ZVAD, or IL-1R antagonist, Kineret. TLR agonists induced PGE2 in macrophages exclusively via IL-1β-independent mechanisms. In contrast, ZVAD and Kineret reduced PGE2 production in LPS-treated (but not in Pam3CSK4-treated) monocytes, by 30–60%. Recombinant human IL-1β augmented COX-2 and mPGES-1 mRNA and PGE2 production in LPS-pretreated monocytes but not in un-primed or Pam3CSK4-primed monocytes. This difference was explained by the finding that LPS but not Pam3CSK4 induced phosphorylation of IRF3 in monocytes suggesting activation of the TRIF signaling pathway. Knocking down TRIF, TRAM, or IRF3 genes by siRNA inhibited IL-1β-induced COX-2 and mPGES-1 mRNA. Blocking of TLR4 endocytosis during LPS priming prevented the increase in PGE2 production by exogenous IL-1β. Our data showed that TLR2 agonists induce PGE2 in monocytes independently from IL-1β. In the case of TLR4, IL-1β augments PGE2 production in LPS-primed monocytes (but not in macrophages) through a mechanism that requires TLR4 internalization and activation of the TRIF/IRF3 pathway. These findings suggest a key role for blood monocytes in the rapid onset of fever in animals and humans exposed to bacterial products and some novel adjuvants. PMID:24870145

  15. Glycolytic pathway affects differentiation of human monocytes to regulatory macrophages.

    PubMed

    Suzuki, Hiroaki; Hisamatsu, Tadakazu; Chiba, Sayako; Mori, Kiyoto; Kitazume, Mina T; Shimamura, Katsuyoshi; Nakamoto, Nobuhiro; Matsuoka, Katsuyoshi; Ebinuma, Hirotoshi; Naganuma, Makoto; Kanai, Takanori

    2016-08-01

    Cellular metabolic state and individual metabolites have been reported to regulate the functional phenotype of immune cells. Cytokine production by regulatory and inflammatory macrophages is thought to mainly involve fatty acid oxidation and glycolysis, respectively, which fuel mitochondrial oxidative phosphorylation. However, the association between metabolic pathways and the acquisition of specific macrophage phenotypes remains unclear. This study assessed the relationship between glycolysis and the differentiation of regulatory macrophages. Human monocytes derived from peripheral blood were cultured in vitro in the presence of macrophage colony-stimulating factor to yield regulatory macrophages (M-Mϕs). M-Mϕs had a regulatory macrophage phenotype and produced substantial IL-10 following stimulation with lipopolysaccharide. To analyze the role of glycolysis, glycolysis inhibitors (2-deoxy-d-glucose or dichloroacetate) were added during M-Mϕ differentiation. These cells cultured with glycolysis inhibitors produced significantly lower amounts of IL-10, but produced significantly higher amounts of IL-6 compared to M-Mϕs differentiated without glycolysis inhibitors. Such phenotypic change of M-Mϕs differentiated with glycolysis inhibitors was associated with the alteration of the gene expression pattern related to macrophage differentiation, such as CSF1, MMP9 and VEGFA. M-Mϕs differentiated with glycolysis inhibitors seemed to retain plasticity to become IL-10 producing cells. Furthermore, increased level of pyruvate in culture medium was found to partially reverse the effects of glycolysis inhibitors on cytokine production of M-Mϕs. These results indicate the importance of glycolytic pathway in macrophage differentiation to a regulatory phenotype, and pyruvate may be one of the key metabolites in this process. PMID:27208804

  16. Infection of monocyte/macrophages by human T lymphotropic virus type III.

    PubMed Central

    Ho, D D; Rota, T R; Hirsch, M S

    1986-01-01

    Normal blood-derived monocyte/macrophages were found to be susceptible to infection in vitro by human T lymphotropic virus type III (HTLV-III), the etiologic agent of the acquired immunodeficiency syndrome. In addition, HTLV-III was recovered from monocyte/macrophages of patients infected with this virus. The above findings raise the possibility that HTLV-III-infected monocyte/macrophages may serve as a vehicle for the dissemination of virus to target organs and as a reservoir for viral persistence, as has been shown for other lentiviruses including visna virus and caprine arthritis encephalitis virus. PMID:2422213

  17. Augmented TLR2 Expression on Monocytes in both Human Kawasaki Disease and a Mouse Model of Coronary Arteritis

    PubMed Central

    Lin, I-Chun; Kuo, Ho-Chang; Lin, Ying-Jui; Wang, Feng-Shen; Wang, Lin; Huang, Shun-Chen; Chien, Shao-Ju; Huang, Chien-Fu; Wang, Chih-Lu; Yu, Hong-Ren; Chen, Rong-Fu; Yang, Kuender D.

    2012-01-01

    Background Kawasaki disease (KD) of unknown immunopathogenesis is an acute febrile systemic vasculitis and the leading cause of acquired heart diseases in childhood. To search for a better strategy for the prevention and treatment of KD, this study compared and validated human KD immunopathogenesis in a mouse model of Lactobacillus casei cell wall extract (LCWE)-induced coronary arteritis. Methods Recruited subjects fulfilled the criteria of KD and were admitted for intravenous gamma globulin (IVIG) treatment at the Kaohsiung Chang Gung Memorial Hospital from 2001 to 2009. Blood samples from KD patients were collected before and after IVIG treatment, and cardiovascular abnormalities were examined by transthoracic echocardiography. Wild-type male BALB/c mice (4-week-old) were intraperitoneally injected with LCWE (1 mg/mL) to induce coronary arteritis. The induced immune response in mice was examined on days 1, 3, 7, and 14 post injections, and histopathology studies were performed on days 7 and 14. Results Both human KD patients and LCWE-treated mice developed coronary arteritis, myocarditis, valvulitis, and pericarditis, as well as elevated plasma levels of interleukin (IL)-2, IL-6, IL-10, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α in acute phase. Most of these proinflammatory cytokines declined to normal levels in mice, whereas normal levels were achieved in patients only after IVIG treatment, with a few exceptions. Toll-like receptor (TLR)-2, but not TLR4 surface enhancement on circulating CD14+ monocytes, was augmented in KD patients before IVIG treatment and in LCWE-treated mice, which declined in patients after IVIG treatment. Conclusion This result suggests that that not only TLR2 augmentation on CD14+ monocytes might be an inflammatory marker for both human KD patients and LCWE-induced CAL mouse model but also this model is feasible for studying therapeutic strategies of coronary arteritis in human KD by modulating TLR2

  18. FGF23 inhibits extra-renal synthesis of 1,25-dihydroxyvitamin D in human monocytes

    PubMed Central

    Bacchetta, Justine; Sea, Jessica L; Chun, Rene F; Lisse, Thomas S; Wesseling-Perry, Katherine; Gales, Barbara; Adams, John S.; Salusky, Isidro B; Hewison, Martin

    2012-01-01

    Vitamin D is a potent stimulator of monocyte innate immunity, with this effect being mediated via intracrine conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25(OH)2D). In the kidney synthesis of 1,25(OH)2D is suppressed by fibroblast growth factor 23 (FGF23), via transcriptional suppression of the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). We hypothesized that FGF23 also suppresses CYP27B1 in monocytes, with concomitant effects on intracrine responses to 1,25(OH)2D. Monocytes from healthy donor peripheral blood mononuclear cells (PBMCm) and from peritoneal dialysate effluent from kidney disease patients (PDm) were assessed at baseline to confirm the presence of mRNA for FGF23 receptors (FGFRs), with Klotho and FGFR1 being more strongly expressed than FGFR2/3/4 in both cell types. Immunohistochemistry showed co-expression of Klotho and FGFR1 in PBMCm and PDm, with this effect being enhanced following treatment with FGF23 in PBMCm but not PDm. Treatment with FGF23 activated MAP kinase (MAPK) and Akt pathways in PBMCm, demonstrating functional FGFR signaling in these cells. FGF23 treatment of PBMCm and PDm decreased expression of mRNA for CYP27B1. In PBMCm this was associated with downregulation of 25OHD to 1,25(OH)2D metabolism, and concomitant suppression of intracrine induced 24-hydroxylase (CYP24A1) and antibacterial cathelicidin (LL37). FGF23 suppression of CYP27B1 was particularly pronounced in PBMCm treated with interleukin-15 to stimulate synthesis of 1,25(OH)2D. These data indicate that FGF23 can inhibit extra-renal expression of CYP27B1 and subsequent intracrine responses to 1,25(OH)2D in two different human monocyte models. Elevated expression of FGF23 may therefore play a crucial role in defining immune responses to vitamin D and this, in turn, may be a key determinant of infection in patients with CKD. PMID:22886720

  19. 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...

  20. Comparison of gene expression profiles between human and mouse monocyte subsets

    PubMed Central

    Ingersoll, Molly A.; Spanbroek, Rainer; Lottaz, Claudio; Gautier, Emmanuel L.; Frankenberger, Marion; Hoffmann, Reinhard; Lang, Roland; Haniffa, Muzlifah; Collin, Matthew; Tacke, Frank; Habenicht, Andreas J. R.

    2010-01-01

    Blood of both humans and mice contains 2 main monocyte subsets. Here, we investigated the extent of their similarity using a microarray approach. Approximately 270 genes in humans and 550 genes in mice were differentially expressed between subsets by 2-fold or more. More than 130 of these gene expression differences were conserved between mouse and human monocyte subsets. We confirmed numerous of these differences at the cell surface protein level. Despite overall conservation, some molecules were conversely expressed between the 2 species' subsets, including CD36, CD9, and TREM-1. Other differences included a prominent peroxisome proliferator-activated receptor γ (PPARγ) signature in mouse monocytes, which is absent in humans, and strikingly opposed patterns of receptors involved in uptake of apoptotic cells and other phagocytic cargo between human and mouse monocyte subsets. Thus, whereas human and mouse monocyte subsets are far more broadly conserved than currently recognized, important differences between the species deserve consideration when models of human disease are studied in mice. PMID:19965649

  1. 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

  2. MicroRNA expression profiling of human blood monocyte subsets highlights functional differences

    PubMed Central

    Dang, Truong-Minh; Wong, Wing-Cheong; Ong, Siew-Min; Li, Peng; Lum, Josephine; Chen, Jinmiao; Poidinger, Michael; Zolezzi, Francesca; Wong, Siew-Cheng

    2015-01-01

    Within human blood there are two subsets of monocytes that can be identified by differential expression of CD16. Although numerous phenotypic and functional differences between the subsets have been described, little is known of the mechanisms underlying the distinctive properties of the two subsets. MicroRNAs (miRNAs) are small non-coding RNAs that can regulate gene expression through promoting mRNA degradation or repressing translation, leading to alterations in cellular processes. Their potential influence on the functions of monocyte subsets has not been investigated. In this study, we employed microarray analysis to define the miRNA expression profile of human monocyte subsets. We identified 66 miRNAs that were differentially expressed (DE) between CD16+ and CD16− monocytes. Gene ontology analysis revealed that the predicted targets of the DE miRNAs were predominantly associated with cell death and cellular movement. We validated the functional impacts of selected DE miRNAs in CD16− monocytes, over-expression of miR-432 significantly increases apoptosis, and inhibiting miR-19a significantly reduces cell motility. Furthermore, we found that miR-345, another DE miRNA directly targets the transcription factor RelA in monocytes, which resulted in the differential expression of RelA in monocyte subsets. This implicates miR-345 indirect regulation of many genes downstream of RelA, including important inflammatory mediators. Together, our data show that DE miRNAs could contribute substantially to regulating the functions of human blood monocytes. PMID:25707426

  3. Modulation of human monocyte/macrophage activity by tocilizumab, abatacept and etanercept: An in vitro study.

    PubMed

    Obeng, Joyce Afrakoma; Amoruso, Angela; Camaschella, Gian Luca Ermanno; Sola, Daniele; Brunelleschi, Sandra; Fresu, Luigia Grazia

    2016-06-01

    Tocilizumab, etanercept and abatacept are biological drugs used in the therapy of Rheumatoid Arthritis (RA). Their mechanism of action is well documented but their direct effects on human monocytes/macrophages have not been fully investigated. The objective of this study was to evaluate in vitro the influence of these drugs on monocytes/macrophages from healthy volunteers. Human monocytes were isolated from healthy anonymous volunteers and cultured as such or differentiated to monocyte-derived macrophages (MDMs). The effect of tocilizumab, etanercept and abatacept (at concentrations similar to those in plasma of patients) on superoxide anion production, matrix metalloproteinase-9 (MMP-9) gene expression and activity, Peroxisome Proliferator-Activated Receptor (PPAR)γ expression and cell phenotype was evaluated. Exposure of monocytes/macrophages to tocilizumab, etanercept or abatacept resulted in a significant decrease of the PMA-induced superoxide anion production. Interestingly, the expression of PPARγ was significantly increased only by tocilizumab, while etanercept was the only one able to significantly reduce MMP-9 gene expression and inhibit the LPS-induced MMP-9 activity in monocytes. When etanercept and abatacept were added to the differentiating medium, both significantly reduced the amount of CD206(+)MDM. This study demonstrates that etanercept, abatacept and tocilizumab affect differently human monocytes/macrophages. In particular, the IL-6 antagonist tocilizumab seems to be more effective in inducing an anti-inflammatory phenotype of monocytes/macrophages compared to etanercept and abatacept, also in light of the up-regulation of PPARγ whose anti-inflammatory effects are well recognised. PMID:26997366

  4. Organochlorine insecticides induce NADPH oxidase-dependent reactive oxygen species in human monocytic cells via phospholipase A2/arachidonic acid.

    PubMed

    Mangum, Lee C; Borazjani, Abdolsamad; Stokes, John V; Matthews, Anberitha T; Lee, Jung Hwa; Chambers, Janice E; Ross, Matthew K

    2015-04-20

    Bioaccumulative organohalogen chemicals, such as organochlorine (OC) insecticides, have been increasingly associated with disease etiology; however, the mechanistic link between chemical exposure and diseases, such as atherosclerosis, cancer, and diabetes, is complex and poorly defined. Systemic oxidative stress stemming from OC exposure might play a vital role in the development of these pathologies. Monocytes are important surveillance cells of the innate immune system that respond to extracellular signals possessing danger-associated molecular patterns by synthesizing oxyradicals, such as superoxide, for the purpose of combating infectious pathogens. We hypothesized that OC chemicals can be toxic to monocytes because of an inappropriate elevation in superoxide-derived reactive oxygen species (ROS) capable of causing cellular oxidative damage. Reactive oxyradicals are generated in monocytes in large part by NADPH oxidase (Nox). The present study was conducted to examine the ability of two chlorinated cyclodiene compounds, trans-nonachlor and dieldrin, as well as p,p'-DDE, a chlorinated alicyclic metabolite of DDT, to stimulate Nox activity in a human monocytic cell line and to elucidate the mechanisms for this activation. Human THP-1 monocytes treated with either trans-nonachlor or dieldrin (0.1-10 μM in the culture medium) exhibited elevated levels of intracellular ROS, as evidenced by complementary methods, including flow cytometry analysis using the probe DCFH-DA and hydroethidine-based fluorometric and UPLC-MS assays. In addition, the induced reactive oxygen flux caused by trans-nonachlor was also observed in two other cell lines, murine J774 macrophages and human HL-60 cells. The central role of Nox in OC-mediated oxidative stress was demonstrated by the attenuated superoxide production in OC-exposed monocytes treated with the Nox inhibitors diphenyleneiodonium and VAS-2870. Moreover, monocytes challenged with OCs exhibited increased phospho-p47(phox

  5. Human Monocyte Subsets at Homeostasis and Their Perturbation in Numbers and Function in Filarial Infection

    PubMed Central

    Moore, Vanessa; Bennuru, Sasisekhar; McDonald-Fleming, Renee; Ganesan, Sundar; Cotton, Rachel; Anuradha, Rajamanickam; Babu, Subash; Nutman, Thomas B.

    2014-01-01

    To characterize the function and plasticity of the major human circulating monocyte populations and to explore their role in systemic helminth infection, highly purified (by flow-based sorting) human monocyte subsets (CD14hi/CD16neg [classical], CD14+ or hi/CD16med [intermediate], and CD14neg/CD16hi [nonclassical]) were examined at homeostasis and after activation. Among these three subsets the classical and intermediate subsets were found to be the major sources of inflammatory and regulatory cytokines, as well as cytokines/chemokines associated with alternative activation, whereas the nonclassical and classical populations demonstrated an ability to transmigrate through endothelial monolayers. Moreover, it was primarily the classical subset that was the most efficient in promoting autologous T cell proliferation. The distribution of these subsets changed in the context of a systemic helminth (Wuchereria bancrofti) infection such that patent infection altered the frequency and distribution of these monocyte subsets with the nonclassical monocytes being expanded (almost 2-fold) in filarial infection. To understand further the filarial/monocyte interface, in vitro modeling demonstrated that the classical subset internalized filarial antigens more efficiently than the other two subsets but that the parasite-driven regulatory cytokine interleukin-10 was exclusively coming from the intermediate subset. Our data suggest that monocyte subsets have a differential function at homeostasis and in response to helminth parasites. PMID:25114121

  6. 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

  7. 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. PMID:24823811

  8. Evidence for specific annexin I-binding proteins on human monocytes.

    PubMed Central

    Goulding, N J; Pan, L; Wardwell, K; Guyre, V C; Guyre, P M

    1996-01-01

    Recombinant human annexin I and a monoclonal antibody specific for this protein (mAb 1B) were used to investigate surface binding of this member of the annexin family of proteins to peripheral blood monocytes. Flow cytometric analysis demonstrated trypsin-sensitive, saturable binding of annexin I to human peripheral blood monocytes but not to admixed lymphocytes. A monoclonal antibody that blocks the anti-phospholipase activity of annexin I also blocked its binding to monocytes. These findings suggest the presence of specific binding sites on monocytes. Furthermore, surface iodination, immunoprecipitation and SDS/PAGE analysis were used to identify two annexin I-binding proteins on the surface of monocytes with molecular masses of 15 kDa and 18 kDa respectively. The identification and characterization of these annexin I-binding molecules should help us to better understand the specific interactions of annexin I with monocytes that lead to down-regulation of pro-inflammatory cell functions. PMID:8687405

  9. Acceleration of Bone Repair in NOD/SCID Mice by Human Monoosteophils, Novel LL-37-Activated Monocytes

    PubMed Central

    Zhang, Zhifang; Shively, John E.

    2013-01-01

    Background An incomplete understanding of bone forming cells during wound healing and ectopic calcification has led to a search for circulating cells that may fulfill this function. Previously, we showed that monoosteophils, a novel lineage of calcifying/bone-forming cells generated by treatment of monocytes with the natural peptide LL-37, are candidates. In this study, we have analyzed their gene expression profile and bone repair function. Methods and Findings Human monoosteophils can be distinguished from monocytes, macrophages and osteoclasts by their unique up-regulation of integrin α3 and down-regulation of CD14 and CD16. Monoosteophils express high mRNA and protein levels of SPP1 (osteopontin), GPNMB (osteoactivin), CHI3L1 (cartilage glycoprotein-39), CHIT1 (Chitinase 1), MMP-7, CCL22 and MAPK13 (p38MAPKδ). Monocytes from wild type, but not MAPK13 KO mice are also capable of monoosteophil differentiation, suggesting that MAPK13 regulates this process. When human monoosteophils were implanted in a freshly drilled hole in mid-diaphyseal femurs of NOD/SCID mice, significant bone repair required only 14 days compared to at least 24 days in control treated injuries. Conclusion Human derived monoosteophils, characterized as CD45+α3+α3β+CD34−CD14−BAP (bone alkaline phosphatase)− cells, can function in an animal model of bone injury. PMID:23844045

  10. VLA-4 integrin can mediate CD11/CD18-independent transendothelial migration of human monocytes.

    PubMed Central

    Chuluyan, H E; Issekutz, A C

    1993-01-01

    The migration of human monocytes across unactivated and activated human umbilical vein endothelium (HUVE) in response to chemotactic factors was studied, and the adhesion molecules involved were characterized. Migration of blood monocytes or U937 cell line-derived monocytes across unactivated HUVE induced by C5a, was partially inhibited (by 75%) by mAbs (R15.7 or 60.3) to CD18 of the CD11/CD18 complex on the monocyte. However, when the HUVE was pretreated for 5 h with IL-1 alpha (0.1 ng/ml), TNF-alpha (100 U/ml), or LPS (1 ng/ml), migration induced by C5a was no longer inhibited; i.e., migration became CD18 independent. The monocyte CD18-independent migration was completely blocked by mAbs against alpha 4 or beta 1 integrin chains of VLA-4. This migration was also partially inhibited by mAbs against vascular cell adhesion molecule-1 (VCAM-1), a major counter-receptor on HUVE for VLA-4, but not by mAbs to E-selectin or intercellular adhesion molecule-1. The significant CD18-independent migration across "unactivated" HUVE was also inhibited by mAbs against alpha 4 or beta 1 chains of VLA-4, although mAbs against VCAM-1 did not inhibit under these conditions. Finally, considerable VLA-4-dependent transendothelial migration to C5a was also observed with monocytes from a patient with CD18 deficiency (leukocyte adhesion deficiency). These results suggest that (a) there is a major CD18-independent component in monocyte chemotactic factor-dependent migration across activated and unactivated endothelium; (b) that VLA-4 integrin on the monocyte has a major role in this migration; and (c) that VCAM-1 on activated endothelium functions as a counter-receptor in this process, but other ligands for VLA-4, especially on unactivated endothelium, may also be involved. Images PMID:7902847

  11. Acute phase protein and antioxidant responses in dogs with experimental acute monocytic ehrlichiosis treated with rifampicin.

    PubMed

    Karnezi, Dimitra; Ceron, Jose J; Theodorou, Konstantina; Leontides, Leonidas; Siarkou, Victoria I; Martinez, Silvia; Tvarijonaviciute, Asta; Harrus, Shimon; Koutinas, Christos K; Pardali, Dimitra; Mylonakis, Mathios E

    2016-02-29

    There is currently lack of information on the changes of acute phase proteins (APP) and antioxidant markers and their clinical relevance as treatment response indicators in canine monocytic ehrlichiosis (CME). The objective of this study was to investigate the patterns of C-reactive protein (CRP), haptoglobin (Hp), ferritin and paraoxonase-1 (PON-1) during treatment of dogs with acute CME with rifampicin. Blood serum samples from ten Beagle dogs with experimental acute CME were retrospectively examined. Five dogs (Group A) were treated with rifampicin (10mg/Kg/24h), per os, for 3 weeks and 5 dogs (Group B) received no treatment (infected controls). Two Beagle dogs served as uninfected controls. Blood serum samples were serially examined prior to Ehrlichia canis inoculation and on post-inoculation days 14, 21, 28, 35 and 42. Significant changes of CRP, Hp, ferritin and PON-1 values were found in the majority of infected dogs. However, their concentrations did not differ between the two groups during the treatment observation period. The results of this study indicate that although several APP and PON-1 tend to significantly change in the majority of dogs with acute CME, they were of limited clinical relevance as treatment response indicators in this experimental setting. PMID:26854345

  12. Dendritic Cells and Monocytes with Distinct Inflammatory Responses Reside in Lung Mucosa of Healthy Humans.

    PubMed

    Baharom, Faezzah; Thomas, Saskia; Rankin, Gregory; Lepzien, Rico; Pourazar, Jamshid; Behndig, Annelie F; Ahlm, Clas; Blomberg, Anders; Smed-Sörensen, Anna

    2016-06-01

    Every breath we take contains potentially harmful pathogens or allergens. Dendritic cells (DCs), monocytes, and macrophages are essential in maintaining a delicate balance of initiating immunity without causing collateral damage to the lungs because of an exaggerated inflammatory response. To document the diversity of lung mononuclear phagocytes at steady-state, we performed bronchoscopies on 20 healthy subjects, sampling the proximal and distal airways (bronchial wash and bronchoalveolar lavage, respectively), as well as mucosal tissue (endobronchial biopsies). In addition to a substantial population of alveolar macrophages, we identified subpopulations of monocytes, myeloid DCs (MDCs), and plasmacytoid DCs in the lung mucosa. Intermediate monocytes and MDCs were highly frequent in the airways compared with peripheral blood. Strikingly, the density of mononuclear phagocytes increased upon descending the airways. Monocytes from blood and airways produced 10-fold more proinflammatory cytokines than MDCs upon ex vivo stimulation. However, airway monocytes were less inflammatory than blood monocytes, suggesting a more tolerant nature. The findings of this study establish how to identify human lung mononuclear phagocytes and how they function in normal conditions, so that dysregulations in patients with respiratory diseases can be detected to elucidate their contribution to immunity or pathogenesis. PMID:27183618

  13. Differential Oxidative Stress Induced by Dengue Virus in Monocytes from Human Neonates, Adult and Elderly Individuals

    PubMed Central

    Valero, Nereida; Mosquera, Jesús; Añez, Germán; Levy, Alegria; Marcucci, Rafael; de Mon, Melchor Alvarez

    2013-01-01

    Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO) has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group) were infected with different dengue virus types (DENV- 1 to 4) and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease. PMID:24069178

  14. β2-Agonist clenbuterol hinders human monocyte differentiation into dendritic cells.

    PubMed

    Giordani, Luciana; Cuzziol, Noemi; Del Pinto, Tamara; Sanchez, Massimo; Maccari, Sonia; Massimi, Alessia; Pietraforte, Donatella; Viora, Marina

    2015-12-10

    Clenbuterol (CLB) is a beta2-adrenergic agonist commonly used in asthma therapy, but is also a non-steroidal anabolic drug often abused in sport doping practices. Here we evaluated the in vitro impact of CLB on the physiology and function of human monocytes and dendritic cells (DCs), instrumental in the development of immune responses. We demonstrate that CLB inhibits the differentiation of monocytes into DCs and this effect is specific and dependent on β2-adrenergic receptor (AR) activation. We found that CLB treatment reduced the percentage of CD1a(+) immature DCs, while increasing the frequency of monocytes retaining CD14 surface expression. Moreover, CLB inhibited tumor necrosis factor-alpha (TNF-alpha) enhanced IL-(interleukin)-10 and IL-6 production. In contrast, CLB did not modulate the phenotypic and functional properties of monocytes and DCs, such as the surface expression of HLA-DR, CD83, CD80 and CD86 molecules, cytokine production, immunostimulatory activity and phagocytic activity. Moreover, we found that CLB did not modulate the activation of NF-kB in DCs. Moreover, we found that the differentiation of monocytes into DCs was associated with a significant decrease of β2-ARs mRNA expression. These results provide new insights on the effect of CLB on monocyte differentiation into DCs. Considering the frequent illegal use of CLB in doping, our work suggests that this drug is potentially harmful to immune responses decreasing the supply of DCs, thus subverting immune surveillance. PMID:26524508

  15. Induction of a type I interferon signature in normal human monocytes by gadolinium-based contrast agents: comparison of linear and macrocyclic agents

    PubMed Central

    Wermuth, P J; Jimenez, S A

    2014-01-01

    The gadolinium-based contrast agent (GdBCA) Omniscan activates human macrophages through Toll-like receptor (TLR)-4 and TLR-7 signalling. To explore the mechanisms responsible we compared the ability of linear and macrocyclic GdBCA to induce a type I interferon signature and a proinflammatory/profibrotic phenotype in normal human monocytes in vitro. Expression of genes associated with type I interferon signalling and inflammation and production of their corresponding proteins were determined. Both linear and macrocyclic GdBCA stimulated expression of multiple type I interferon-regulated genes and the expression of numerous chemokines, cytokines and growth factors in normal human peripheral blood monocytes. There was no correlation between the magnitude of the measured response and the Gd chelate used. To explore the mechanisms responsible for GdBCA induction of fibrosis in nephrogenic systemic fibrosis (NSF) in vitro, normal human dermal fibroblasts were incubated with GdBCA-treated monocyte culture supernatants and the effects on profibrotic gene expression were examined. Supernatants from monocytes exposed to all GdBCA stimulated types I and III collagen, fibronectin and α-smooth muscle actin (α-SMA) expression in normal dermal fibroblasts. The results indicate that the monocyte activation induced by GdBCA may be the initial step in the development of GdBCA associated fibrosis in NSF. PMID:24111526

  16. Differential Activation of Human Monocytes and Lymphocytes by Distinct Strains of Trypanosoma cruzi

    PubMed Central

    Magalhães, Luísa M. D.; Viana, Agostinho; Chiari, Egler; Galvão, Lúcia M. C.; Gollob, Kenneth J.; Dutra, Walderez O.

    2015-01-01

    Background 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. Methodology/Principal Findings 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. Conclusion/Significance 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. PMID:26147698

  17. Cinnamic Acid Is Partially Involved in Propolis Immunomodulatory Action on Human Monocytes

    PubMed Central

    Conti, Bruno José; Búfalo, Michelle Cristiane; Golim, Marjorie de Assis; Sforcin, José Maurício

    2013-01-01

    Propolis is a beehive product used in traditional medicine due to its biological properties. It shows a complex chemical composition including phenolics, such as cinnamic acid (Ci). The mechanisms of action of propolis have been the subject of research recently; however, the involvement of Ci on propolis activity was not investigated on immune cells. Ci effects were evaluated on human monocytes, assessing the expression of Toll-like receptors (TLRs), HLA-DR, and CD80. Cytokine production (TNF-α and IL-10) and the fungicidal activity of monocytes were evaluated as well. Data showed that Ci downregulated TLR-2, HLA-DR, and CD80 and upregulated TLR-4 expression by human monocytes. High concentrations of Ci inhibited both TNF-α and IL-10 production, whereas the same concentrations induced a higher fungicidal activity against Candida albicans. TNF-α and IL-10 production was decreased by blocking TLR-4, while the fungicidal activity of monocytes was not affected by blocking TLRs. These results suggest that Ci modulated antigen receptors, cytokine production, and the fungicidal activity of human monocytes depending on concentration, and TLR-4 may be involved in its mechanism of action. Ci seemed to be partially involved in propolis activities. PMID:23762102

  18. Cinnamic Acid is partially involved in propolis immunomodulatory action on human monocytes.

    PubMed

    Conti, Bruno José; Búfalo, Michelle Cristiane; Golim, Marjorie de Assis; Bankova, Vassya; Sforcin, José Maurício

    2013-01-01

    Propolis is a beehive product used in traditional medicine due to its biological properties. It shows a complex chemical composition including phenolics, such as cinnamic acid (Ci). The mechanisms of action of propolis have been the subject of research recently; however, the involvement of Ci on propolis activity was not investigated on immune cells. Ci effects were evaluated on human monocytes, assessing the expression of Toll-like receptors (TLRs), HLA-DR, and CD80. Cytokine production (TNF- α and IL-10) and the fungicidal activity of monocytes were evaluated as well. Data showed that Ci downregulated TLR-2, HLA-DR, and CD80 and upregulated TLR-4 expression by human monocytes. High concentrations of Ci inhibited both TNF- α and IL-10 production, whereas the same concentrations induced a higher fungicidal activity against Candida albicans. TNF- α and IL-10 production was decreased by blocking TLR-4, while the fungicidal activity of monocytes was not affected by blocking TLRs. These results suggest that Ci modulated antigen receptors, cytokine production, and the fungicidal activity of human monocytes depending on concentration, and TLR-4 may be involved in its mechanism of action. Ci seemed to be partially involved in propolis activities. PMID:23762102

  19. Human monocytes kill M-CSF-expressing glioma cells by BK channel activation.

    PubMed

    Hoa, Neil T; Zhang, Jian Gang; Delgado, Christina L; Myers, Michael P; Callahan, Linda L; Vandeusen, Gerald; Schiltz, Patric M; Wepsic, H Terry; Jadus, Martin R

    2007-02-01

    In this study, human monocytes/macrophages were observed to kill human U251 glioma cells expressing membrane macrophage colony-stimulating factor (mM-CSF) via a swelling and vacuolization process called paraptosis. Human monocytes responded to the mM-CSF-transduced U251 glioma cells, but not to viral vector control U251 glioma cells (U251-VV), by producing a respiratory burst within 20 min. Using patch clamp techniques, functional big potassium (BK) channels were observed on the membrane of the U251 glioma cell. It has been previously reported that oxygen indirectly regulates BK channel function. In this study, it was demonstrated that prolonged BK channel activation in response to the respiratory burst induced by monocytes initiates paraptosis in selected glioma cells. Forced BK channel opening within the glioma cells by BK channel activators (phloretin or pimaric acid) induced U251 glioma cell swelling and vacuolization occurred within 30 min. U251 glioma cell cytotoxicity, induced by using BK channel activators, required between 8 and 12 h. Swelling and vacuolization induced by phloretin and pimaric acid was prevented by iberiotoxin, a specific BK channel inhibitor. Confocal fluorescence microscopy demonstrated BK channels co-localized with the endoplasmic reticulum and mitochondria, the two targeted organelles affected in paraptosis. Iberiotoxin prevented monocytes from producing death in mM-CSF-expressing U251glioma cells in a 24 h assay. This study demonstrates a novel mechanism whereby monocytes can induce paraptosis via the disruption of internal potassium ion homeostasis. PMID:17318194

  20. 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

    Johnson, Chase L; Green, Daniel S; 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

  1. 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

  2. Functional and phenotypic characteristics of alternative activation induced in human monocytes by interleukin-4 or the parasitic nematode Brugia malayi.

    PubMed

    Semnani, Roshanak Tolouei; Mahapatra, Lily; Moore, Vanessa; Sanprasert, Vivornpun; Nutman, Thomas B

    2011-10-01

    Human monocytes from patients with patent filarial infections are studded with filarial antigen and express markers associated with alternative activation of macrophages (MΦ). To explore the role of filaria-derived parasite antigen in differentiation of human monocytes, cells were exposed to microfilariae (mf) of Brugia malayi, and their phenotypic and functional characteristics were compared with those of monocytes exposed to factors known to generate either alternatively (interleukin-4 [IL-4]) or classically (macrophage colony-stimulating factor [MCSF]) activated MΦ. IL-4 upregulated mRNA expression of CCL13, CCL15, CCL17, CCL18, CCL22, CLEC10A, MRC1, CADH1, CD274, and CD273 associated with alternative activation of MΦ but not arginase 1. IL-4-cultured monocytes had a diminished ability to promote proliferation of both CD4(+) and CD8(+) T cells compared to that of unexposed monocytes. Similar to results with IL-4, exposure of monocytes to live mf induced upregulation of CCL15, CCL17, CCL18, CCL22, CD274, and CD273 and downregulation of Toll-like receptor 3 (TLR3), TLR5, and TLR7. In contrast to results with MCSF-cultured monocytes, exposure of monocytes to mf resulted in significant inhibition of the phagocytic ability of these cells to the same degree as that seen with IL-4. Our data suggest that short exposure of human monocytes to IL-4 induces a phenotypic characteristic of alternative activation and that secreted filarial products skew monocytes similarly. PMID:21788379

  3. AP-1-directed human T cell leukemia virus type 1 viral gene expression during monocytic differentiation.

    PubMed

    Grant, Christian; Jain, Pooja; Nonnemacher, Michael; Flaig, Katherine E; Irish, Bryan; Ahuja, Jaya; Alexaki, Aikaterini; Alefantis, Timothy; Wigdahl, Brian

    2006-09-01

    Human T cell leukemia virus type 1 (HTLV-1) has previously been shown to infect antigen-presenting cells and their precursors in vivo. However, the role these important cell populations play in the pathogenesis of HTLV-1-associated myelopathy/tropical spastic paraparesis or adult T cell leukemia remains unresolved. To better understand how HTLV-1 infection of these important cell populations may potentially impact disease progression, the regulation of HTLV-1 viral gene expression in established monocytic cell lines was examined. U-937 promonocytic cells transiently transfected with a HTLV-1 long-terminal repeat (LTR) luciferase construct were treated with phorbol 12-myristate 13-acetate (PMA) to induce cellular differentiation. PMA-induced cellular differentiation resulted in activation of basal and Tax-mediated transactivation of the HTLV-1 LTR. In addition, electrophoretic mobility shift analyses demonstrated that PMA-induced cellular differentiation induced DNA-binding activity of cellular transcription factors to Tax-responsive element 1 (TRE-1) repeat II. Supershift analyses revealed that factors belonging to the activator protein 1 (AP-1) family of basic region/leucine zipper proteins (Fra-1, Fra-2, JunB, and JunD) were induced to bind to TRE-1 repeat II during cellular differentiation. Inhibition of AP-1 DNA-binding activity by overexpression of a dominant-negative c-Fos mutant (A-Fos) in transient expression analyses resulted in severely decreased levels of HTLV-1 LTR activation in PMA-induced U-937 cells. These results have suggested that following infection of peripheral blood monocytes, HTLV-1 viral gene expression may become up-regulated by AP-1 during differentiation into macrophages or dendritic cells. PMID:16829632

  4. Modulation of the effector function of human monocytes for Mycobacterium avium by human immunodeficiency virus-1 envelope glycoprotein gp120.

    PubMed Central

    Shiratsuchi, H; Johnson, J L; Toossi, Z; Ellner, J J

    1994-01-01

    Disseminated Mycobacterium avium infection in AIDS is associated with high tissue burdens (10(9)-10(10) mycobacteria/g tissue) of organism. The basis for the extraordinary susceptibility of AIDS to M. avium infection is unclear. HIV or its constituents may alter mononuclear phagocyte functions resulting in enhanced intracellular M. avium growth. The effects of an envelope glycoprotein (gp120), a transmembrane protein (p121), and core proteins of HIV-1 on M. avium infection of human monocytes were examined. Preculturing monocytes with gp120 inhibited M. avium phagocytosis and consistently enhanced intracellular growth of six M. avium strains. Pretreatment with p121, gag5, or p24 did not inhibit phagocytosis nor enhance intracellular growth of M. avium. Incubation of gp120 with soluble CD4 before addition to monocyte cultures or pretreatment of monocytes with OKT4A abrogated gp120 effects on M. avium phagocytosis and intracellular growth. gp120 also augmented cytokine production by infected monocytes. These results suggest that gp120, but not p121 or core proteins, modulate monocyte phagocytosis and enhance intracellular growth of M. avium at least in part through monocyte CD4 receptors. Direct effects of HIV-1 products may, therefore, contribute to the diathesis of AIDS to develop disseminated M. avium infection and to the extensive replication of the organisms within tissue macrophages. Images PMID:8113420

  5. Binding of Streptococcus mutans SR protein to human monocytes: production of tumor necrosis factor, interleukin 1, and interleukin 6.

    PubMed

    Soell, M; Holveck, F; Schöller, M; Wachsmann, R D; Klein, J P

    1994-05-01

    To examine the possible implication of protein SR, an I/II-related antigen from Streptococcus mutans OMZ 175 (serotype f), in inflammatory reactions, we tested the immunomodulatory effects of protein SR on human monocytes. Using biotinylated protein, we provide evidence that protein SR binds to human monocytes in dose-, time-, and calcium-dependent manners through specific interactions. These results were confirmed by competition experiments using either soluble human monocyte extract or anti-SR immunoglobulin G. Binding occurred through lectin-like interactions between SR and carbohydrate portions of monocyte membrane glycoproteins, since binding could be inhibited by several sugars, especially fucose and N-acetylneuraminic acid (NANA), which were confirmed by ligand blotting to be the primer ligands recognized by SR on human monocyte extracts. The ability of protein SR to stimulate the production of cytokines by human circulating monocytes was then examined. The release of tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta, and interleukin 6 is time and dose dependent and not affected by the addition of polymyxin B. Activation of monocytes resulted from specific binding of SR to NANA and fucose present on cell surface glycoproteins since TNF-alpha release could be inhibited by sialidase and pronase treatment of monocytes and by NANA and fucose. These results confirm that sialic acid and fucose present on cell surface macromolecules and especially glycoproteins are needed for the binding of SR to monocytes and for the release of TNF-alpha. PMID:8168943

  6. Binding of Streptococcus mutans SR protein to human monocytes: production of tumor necrosis factor, interleukin 1, and interleukin 6.

    PubMed Central

    Soell, M; Holveck, F; Schöller, M; Wachsmann, R D; Klein, J P

    1994-01-01

    To examine the possible implication of protein SR, an I/II-related antigen from Streptococcus mutans OMZ 175 (serotype f), in inflammatory reactions, we tested the immunomodulatory effects of protein SR on human monocytes. Using biotinylated protein, we provide evidence that protein SR binds to human monocytes in dose-, time-, and calcium-dependent manners through specific interactions. These results were confirmed by competition experiments using either soluble human monocyte extract or anti-SR immunoglobulin G. Binding occurred through lectin-like interactions between SR and carbohydrate portions of monocyte membrane glycoproteins, since binding could be inhibited by several sugars, especially fucose and N-acetylneuraminic acid (NANA), which were confirmed by ligand blotting to be the primer ligands recognized by SR on human monocyte extracts. The ability of protein SR to stimulate the production of cytokines by human circulating monocytes was then examined. The release of tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta, and interleukin 6 is time and dose dependent and not affected by the addition of polymyxin B. Activation of monocytes resulted from specific binding of SR to NANA and fucose present on cell surface glycoproteins since TNF-alpha release could be inhibited by sialidase and pronase treatment of monocytes and by NANA and fucose. These results confirm that sialic acid and fucose present on cell surface macromolecules and especially glycoproteins are needed for the binding of SR to monocytes and for the release of TNF-alpha. Images PMID:8168943

  7. Differential in vivo activation of monocyte subsets during low-grade inflammation through experimental endotoxemia in humans.

    PubMed

    Thaler, B; Hohensinner, P J; Krychtiuk, K A; Matzneller, P; Koller, L; Brekalo, M; Maurer, G; Huber, K; Zeitlinger, M; Jilma, B; Wojta, J; Speidl, W S

    2016-01-01

    Human monocytes are a heterogeneous cell population, which can be divided into a classical (CD14++CD16-), a non-classical (CD14+CD16+), and an intermediate (CD14++CD16+) subset. We hypothesized that low-grade inflammation may differentially affect monocyte subsets. We used a human lipopolysaccharide (LPS) infusion model to mimic low-grade inflammation to identify, which monocyte subsets are preferentially activated under these conditions. Monocyte subsets were identified by staining for CD14 and CD16, activation status of monocytes was analyzed by staining for CD11b and a novel in situ mRNA hybridization approach to detect IL-6 and IL-8 specific mRNA at the single-cell level by flow cytometry. After LPS challenge, cell numbers of monocyte subsets dropped after 2 h with cell numbers recovering after 6 h. Distribution of monocyte subsets was skewed dramatically towards the intermediate subset after 24 h. Furthermore, intermediate monocytes displayed the largest increase of CD11b expression after 2 h. Finally, IL-6 and IL-8 mRNA levels increased in intermediate and non-classical monocytes after 6 h whereas these mRNA levels in classical monocytes changed only marginally. In conclusion, our data indicates that the main responding subset of monocytes to standardized low-grade inflammation induced by LPS in humans is the CD14++CD16+ intermediate subset followed by the CD14+CD16+ non-classical monocyte subset. Circulating classical monocytes showed comparably less reaction to LPS challenge in vivo. PMID:27444882

  8. Differential in vivo activation of monocyte subsets during low-grade inflammation through experimental endotoxemia in humans

    PubMed Central

    Thaler, B.; Hohensinner, P. J.; Krychtiuk, K. A.; Matzneller, P.; Koller, L.; Brekalo, M.; Maurer, G.; Huber, K.; Zeitlinger, M.; Jilma, B.; Wojta, J.; Speidl, W. S.

    2016-01-01

    Human monocytes are a heterogeneous cell population, which can be divided into a classical (CD14++CD16−), a non-classical (CD14+CD16+), and an intermediate (CD14++CD16+) subset. We hypothesized that low-grade inflammation may differentially affect monocyte subsets. We used a human lipopolysaccharide (LPS) infusion model to mimic low-grade inflammation to identify, which monocyte subsets are preferentially activated under these conditions. Monocyte subsets were identified by staining for CD14 and CD16, activation status of monocytes was analyzed by staining for CD11b and a novel in situ mRNA hybridization approach to detect IL-6 and IL-8 specific mRNA at the single-cell level by flow cytometry. After LPS challenge, cell numbers of monocyte subsets dropped after 2 h with cell numbers recovering after 6 h. Distribution of monocyte subsets was skewed dramatically towards the intermediate subset after 24 h. Furthermore, intermediate monocytes displayed the largest increase of CD11b expression after 2 h. Finally, IL-6 and IL-8 mRNA levels increased in intermediate and non-classical monocytes after 6 h whereas these mRNA levels in classical monocytes changed only marginally. In conclusion, our data indicates that the main responding subset of monocytes to standardized low-grade inflammation induced by LPS in humans is the CD14++CD16+ intermediate subset followed by the CD14+CD16+ non-classical monocyte subset. Circulating classical monocytes showed comparably less reaction to LPS challenge in vivo. PMID:27444882

  9. Novel aspect of amphotericin B action: accumulation in human monocytes potentiates killing of phagocytosed Candida albicans.

    PubMed Central

    Martin, E; Stüben, A; Görz, A; Weller, U; Bhakdi, S

    1994-01-01

    The influence of low doses of amphotericin B on the capacity of human monocytes to kill Candida albicans was investigated. Killing rates were quantified by a novel flow cytometric assay and were found to be 37% +/- 3% (standard error of the mean) after 3 h. Preincubation of monocytes for 6 to 20 h with low concentrations of amphotericin B (0.2 microgram/ml) resulted in a markedly augmented fungicidal capacity. Enhancement of killing was 80% +/- 11% (standard error of the mean) over that by the controls. This effect did not appear to be due to amphotericin B-dependent monocyte activation; the respiratory burst and expression of human leukocyte antigen-DR were unaltered, and no stimulation of interleukin-1 beta release occurred. Cell-associated amphotericin B was extracted with acetonitrile and was quantified by scanning spectrophotometry. Amphotericin B appeared to accumulate in the cells, and intracellular concentrations attained after overnight incubation in 1 microgram of the drug per ml were estimated to be in the range of 50 fg per cell. The fact that intracellular accumulation was responsible for the enhanced fungicidal capacity of monocytes was supported by the findings that killing of Staphylococcus aureus remained normal and enhancement of killing of an amphotericin B-resistant C. albicans strain was minimal. Dramatic enhancement of monocyte fungicidal capacity probably extends to other amphotericin B-susceptible fungi and could represent a hitherto unrecognized determinant underlying the curative properties and prophylactic efficacy of this drug. PMID:8141565

  10. Human monocyte/macrophage activation and interleukin 1 generation by biomedical polymers.

    PubMed

    Miller, K M; Anderson, J M

    1988-08-01

    In vitro cell culture techniques were used to evaluate the effect of several clinically significant biomedical polymers on monocyte activation and Interleukin 1 (IL1) production. Isolated human peripheral blood monocytes were cultured in the presence of a panel of five biomedical polymers routinely used in a variety of clinical applications: Polyethylene (PE), silica-free poly-dimethylsiloxane (PDMS), woven Dacron fabric, expanded polytetrafluoroethylene (ePTFE) and the segmented polyurethane, Biomer. Monocytes generated IL1 in the presence of all five materials. Maximal levels of IL1 were generated at 24 h in monocyte-polymer cultures supplemented with serum and additionally stimulated with lipopolysaccharide (LPS). No difference was observed due to serum source. Results from cultures supplemented with fetal bovine serum were not significantly different from those obtained with human serum supplemented cultures. The thymocyte proliferative activity generated by monocytes in the presence of these biomedical polymers was neutralized by a specific polyclonal anti-IL1 antiserum. Statistically significant differences in IL1 production were observed between polymers, allowing their classification according to reactivity into high (Dacron, PE), intermediate (ePTFE) and low (Biomer, PDMS) reactive groups. PMID:3265135

  11. 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.

  12. Human monocytes recognize porcine endothelium via the interaction of galectin 3 and alpha-GAL.

    PubMed

    Jin, Rongyu; Greenwald, Allen; Peterson, Mark D; Waddell, Thomas K

    2006-07-15

    Monocytes are one of the key inflammatory cells recruited to xenografts and play an important role in delayed xenograft rejection. Previous studies have demonstrated the ability of monocytes to bind to the major xenoantigen Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R; however, the receptor that mediates this interaction has yet to be identified. We provide evidence that it is Galectin-3, a approximately 30-kDa lectin that recognizes beta-galactosides (Gal-beta(1-3/4)GlcNAc) and plays diverse roles in many physiological and pathological events. Human monocyte binding is strikingly increased on porcine aortic endothelial cells (PAEC), which express high levels of Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R, compared with human aortic endothelial cells. Human monocytes obtained from healthy donors bind to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R at variable intensities. This variation of binding intensity was consistent and reproducible in individual donors. Galectin-3 is mainly expressed in human monocytes, not lymphocytes. Purified Galectin-3 is able to bind directly to Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R. Galectin-3 can also be affinity isolated from monocytes (and not lymphocytes) using an Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R-biotin/streptavidin-bead pull-down system. Soluble Galectin-3 binds preferentially to PAEC vs human aortic endothelial cells, and this binding can be inhibited by lactose, indicating dependence on the carbohydrate recognition domain of Galectin-3. Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R is at least partly responsible for this phenomenon, as binding decreased after digestion of PAEC with alpha-galactosidase. Furthermore, monocytes pretreated with a blocking anti-Galectin-3 Ab show decreased adhesion to PAEC when compared with isotype control in a parallel plate flow chamber perfusion assay. Thus, we conclude that Galectin-3 expressed in human monocytes is a receptor for the major xenoantigen (Gal-alpha(1,3)Gal-beta(1,4)GlcNAc-R), expressed on porcine endothelial cells

  13. Interleukin-1 and interleukin-6 gene expression in human monocytes stimulated with Salmonella typhimurium porins.

    PubMed Central

    Galdiero, M; Cipollaro de L'ero, G; Donnarumma, G; Marcatili, A; Galdiero, F

    1995-01-01

    The aim of this study was to verify whether Salmonella typhimurium porins can affect the expression of interleukin-1 (IL-1) and interleukin-6 (IL-6) genes. Human monocytes were treated with porins, and total RNAs were analysed by Northern blotting to evaluate the expression of IL-1 alpha, IL-1 beta and IL-6 in both treated and untreated cell cultures. Porins induced a significant increase in IL-1 and IL-6 transcripts. This increase was related to the dose of porins, and it peaked 5 hr after treatment. The same results were obtained when polymyxin B was added to the porin preparation to eliminate eventual traces of lipopolysaccharide (LPS) associated with porins. The porins-mediated increase in interleukin transcripts did not require de novo protein synthesis, and it was because of the enhanced half-life of IL-1 and IL-6 mRNAs, rather an increased rate of gene transcription. These data suggest that porins may affect inflammatory and immunological responses by enhancing the expression of cytokine genes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:8567029

  14. Soy Isoflavones Attenuate Human Monocyte Adhesion to Endothelial Cell–Specific CD54 by Inhibiting Monocyte CD11a1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy-based diets have been shown to protect against the development of atherosclerosis; however, the underlying mechanism(s) remain unknown. Interaction between activated monocytes and inflamed endothelial cells is an early event in atherogenesis. Therefore, we examined whether treatment of monocytes...

  15. HIV-1 induces IL-10 production in human monocytes via a CD4-independent pathway.

    PubMed

    Ji, Jiaxiang; Sahu, Gautam K; Braciale, Vivian L; Cloyd, Miles W

    2005-06-01

    In HIV-infected patients, increased levels of IL-10, mainly produced by virally infected monocytes, were reported to be associated with impaired cell-mediated immune responses. In this study, we investigated how HIV-1 induces IL-10 production in human monocytes. We found that CD14(+) monocytes infected by either HIV-1(213) (X4) or HIV-1(BaL) (R5) produced IL-10, IL-6, tumor necrosis factor-alpha (TNF-alpha), and to a lesser extent, IFN-gamma. However, the capacity of HIV-1 to induce these cytokines was not dependent on virus replication since UV-inactivated HIV-1 induced similar levels of these cytokines. In addition, soluble HIV-1 gp160 could induce CD14(+) monocytes to produce IL-10 but at lower levels. Cross-linking CD4 molecules (XLCD4) with anti-CD4 mAbs and goat anti-mouse IgG (GAM) resulted in high levels of IL-6, TNF-alpha and IFN-gamma but no IL-10 production by CD14(+) monocytes. Interestingly, neither anti-CD4 mAbs nor recombinant soluble CD4 (sCD4) receptor could block IL-10 secretion induced by HIV-1(213), HIV-1(BaL) or HIV-1 gp160 in CD14(+) monocytes, whereas anti-CD4 mAb or sCD4 almost completely blocked the secretion of the other cytokines. Furthermore, HIV-1(213) could induce IL-10 mRNA expression in CD14(+) monocytes while XLCD4 by anti-CD4 mAb and GAM failed to do so. As with IL-10 protein levels, HIV-1(213)-induced IL-10 mRNA expression in CD14(+) monocytes could not be inhibited by anti-CD4 mAb or sCD4. Taken together, HIV-1 binding to CD14(+) monocytes can induce CD4-independent IL-10 production at both mRNA and protein levels. This finding suggests that HIV induces the immunosuppressive IL-10 production in monocytes and is not dependent on CD4 molecules and that interference with HIV entry through CD4 molecules may have no impact on counteracting the effects of IL-10 during HIV infection. PMID:15937058

  16. Oxidative stresses induced by glycoxidized human or bovine serum albumin on human monocytes.

    PubMed

    Rondeau, Philippe; Singh, Nihar Ranjan; Caillens, Henri; Tallet, Frank; Bourdon, Emmanuel

    2008-09-15

    Oxidative stress and protein modifications are frequently observed in numerous disease states. Albumin, the major circulating protein in blood, can undergo increased glycoxidation in diabetes. Protein glycoxidation can lead to the formation of advanced glycoxidation end products, which induce various deleterious effects on cells. Herein, we report the effect of glucose or methylglyoxal-induced oxidative modifications on BSA or HSA protein structures and on THP1 monocyte physiology. The occurrence of oxidative modifications was found to be enhanced in glycoxidized BSA and HSA, after determination of their free thiol group content, relative electrophoretic migration, carbonyl content, and antioxidant activities. Cells treated with glycoxidized albumin exhibited an overgeneration of intracellular reactive oxygen species, impairments in proteasomal activities, enhancements in RAGE expression, and an accumulation of carbonylated proteins. These novel observations made in the presence of a range of modified BSA and HSA facilitate the comparison of the glycoxidation extent of albumin with the oxidative stress induced in cultured monocytes. Finally, this study reconfirms the influence of experimental conditions in which AGEs are generated and the concentration levels in experiments designed to mimic pathological conditions. PMID:18616999

  17. Chlamydia trachomatis growth stimulates interleukin 8 production by human monocytic U-937 cells.

    PubMed Central

    Bianchi, A; Dosquet, C; Henry, S; Couderc, M C; Ferchal, F; Scieux, C

    1997-01-01

    Growth of Chlamydia trachomatis serotypes L2 and L3 in a human monocytic cell line, U-937, increased the rate of interleukin 8 (IL-8) release 100-fold. Heat-killed chlamydiae induced a 10-fold-lower level of production of IL-8. IL-8 may play an important role in the inflammatory reaction to chlamydial infection. PMID:9169785

  18. Differential regulation of TLR4 expression in human B cells and monocytes

    PubMed Central

    Ganley-Leal, Lisa M.; Liang, YanMei; Jagannathan-Bogdan, Madhumita; Farraye, Francis A.; Nikolajczyk, Barbara S.

    2010-01-01

    Toll-like receptor 4 (TLR4) is an innate immune receptor that is constitutively and inducibly activated in monocytes. Although TLR4 is expressed at very low levels on human B cells from healthy individuals, recent reports showed that TLR4 expression and function is elevated in B cells from inflammatory disease patients. New data showed that TLR4 expression on B cell is increased upon stimulation through surface Igμ and CD40 in combination with IL-4. In contrast, monocyte stimulation through CD40 and IL-4 receptors decreased TLR4 surface expression. Analysis of molecular signatures of TLR4 activation in stimulated B cells suggested that TLR4 is regulated by different mechanisms in B cells compared to monocytes. PU.1 and interferon regulatory factor association with the TLR4 promoter are sufficient for TLR4 transcription, but are not sufficient for surface TLR4 expression on B cells. In contrast, the PU.1/IRF combination is sufficient for surface TLR4 expression on monocytes. These data identify mechanisms that can activate B cell TLR4 expression in inflammatory disease patients, and demonstrate that B cells have additional layers of TLR4 regulation absent in monocytes. PMID:20956019

  19. Cytokine and Eicosanoid Production by Cultured Human Monocytes Exposed to Titanium Particulate Debris

    NASA Astrophysics Data System (ADS)

    Robinson, Timothy M.; Manley, Paul A.; Sims, Paul A.; Albrecht, Ralph; Darien, Benjamin J.

    1999-10-01

    Phagocytosis of particulate wear debris from arthroplasties by macrophages induces an inflammatory response that has been linked to implant loosening and premature failure of artificial joints. Inflammatory mediators released by phagocytic macrophages such as tumor necrosis factor-a (TNF-[alpha]), interleukin-1[beta] (IL-1[beta]), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) are believed to play a central role in the pathogenesis of aseptic loosening. The objective of this study was to characterize titanium alloy particulates that closely match wear debris found around joint arthroplasties and to study their effects on the biosynthesis of inflammatory mediators by cultured monocytes. Peripheral blood monocytes were isolated from healthy human volunteers. Monocytes were cultured in 96-well plates for 24 h, washed, and exposed to three concentrations of titanium particulates and controls from 18Ð24 h. Supernatants were assayed for TNF-[alpha], IL-1[beta], IL-6, and PGE2 activity. Energy dispersive X-ray spectroscopy (EDX) verified the titanium alloy to be Ti6A14V. Scanning electron microscopy (SEM) analysis showed significant titanium particulate heterogeneity with approximately 95% of the particles <1 micrometer in diameter. SEM and EDX technology was useful in the characterization of the titanium particulates utilized for in vitro models of titanium-induced cytokine release by monocytes. Incubation of titanium particulates (in concentrations similar to those found around loosened prosthetic joints) with cultured monocytes significantly increased their production of TNF-[alpha], IL-1[beta], and PGE2.

  20. Differentiation of human CD14+ monocytes: an experimental investigation of the optimal culture medium and evidence of a lack of differentiation along the endothelial line

    PubMed Central

    Safi, Wajima; Kuehnl, Andreas; Nüssler, Andreas; Eckstein, Hans-Henning; Pelisek, Jaroslav

    2016-01-01

    The aim of this study was to determine the optimal culturing media for human CD14+ monocytes and to evaluate whether these cells are capable of differentiating into vascular endothelial cells. Human monocytes isolated from peripheral blood were cultured for 1, 3, 7, 10 or 14 days in different media containing either 10% fetal bovine serum (FBS), 10% autologous donor serum (Auto), 10% FBS with interleukin-3 and macrophage colony stimulating factor (FBS-WF) or 10% Auto and the same growth factors (AU-WF). The cells were differentiated using endothelial cell conditioning medium (EC). Viability was measured using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and the cells were characterized by histology, immunohistochemistry and western blot analysis. Monocytes treated with Auto, FBS-WF or AU-WF medium generated a significant higher yield of vital cells after 7 days in culture compared with FBS-only medium (mean difference (MD)=0.318, P=0.01; MD=1.83, P=0.04; or MD=0.271, P=0.01 and MD=0.318, P=0.102). All tested media led to the differentiation of monocytes into macrophages, identified by CD68, especially in the FBS-WF medium (MD=+18.3% P=0.04). Differentiation into ECs caused a significant decrease in cell viability in all media. Endothelial cell markers, including CD31, CD144, VEGF, VEGF-R2 and CD34, could not be detected. Autologous serum significantly increases the yield of monocyte-derived cells with a higher effectiveness than commonly used FBS-only serum. There is no further benefit in culturing monocytes longer than 7 days. The cultivation of monocytes in the tested media leads preferentially to differentiation into macrophages. Differentiation into endothelial cells did not take place. PMID:27080367

  1. The interaction between filarial parasites and human monocyte/macrophage populations.

    PubMed

    Semnani, Roshanak Tolouei

    2013-01-01

    Lymphatic filariasis is a mafor tropical disease affecting approximately 120 million people worldwide. Patent infection, by and large, is clinically asymptomatic but is associated with the inability of T cells to proliferate or produce IFN-γ in response to parasite antigen. Monocyte dysfunction is one hypothesis felt to explain the lack of an antigen-specific T cell response. In fact, monocytes from filaria-infected individuals have been shown to be studded with internalized filarial antigens. Understanding how the phenotype and the function of these monocytes are altered through the internalization of these parasite antigens is one of the areas our laboratory has focused on. In fact, the existence and/or function of alternatively activated macrophages in murine models of filarial infections have been extensively studied. Whether this population of macrophages can be induced in human filarial infections is the main focus of this review. PMID:23456837

  2. IL-3 synergises with basophil-derived IL-4 and IL-13 to promote the alternative activation of human monocytes.

    PubMed

    Borriello, Francesco; Longo, Michele; Spinelli, Rosa; Pecoraro, Antonio; Granata, Francescopaolo; Staiano, Rosaria Ilaria; Loffredo, Stefania; Spadaro, Giuseppe; Beguinot, Francesco; Schroeder, John; Marone, Gianni

    2015-07-01

    Basophil-derived IL-4 is involved in the alternative activation of mouse monocytes, as recently shown in vivo. Whether this applies to human basophils and monocytes has not been established yet. Here, we sought to characterise the interaction between basophils and monocytes and identify the molecular determinants. A basophil-monocyte co-culture model revealed that IL-3 and basophil-derived IL-4 and IL-13 induced monocyte production of CCL17, a marker of alternative activation. Critically, IL-3 and IL-4 acted directly on monocytes to induce CCL17 production through histone H3 acetylation, but did not increase the recruitment of STAT5 or STAT6. Although freshly isolated monocytes did not express the IL-3 receptor α chain (CD123), and did not respond to IL-3 (as assessed by STAT5 phosphorylation), the overnight incubation with IL-4 (especially if associated with IL-3) upregulated CD123 expression. IL-3-activated JAK2-STAT5 pathway inhibitors reduced the CCL17 production in response to IL-3 and IL-4, but not to IL-4 alone. Interestingly, monocytes isolated from allergen-sensitised asthmatic patients exhibited a higher expression of CD123. Taken together, our data show that the JAK2-STAT5 pathway modulates both basophil and monocyte effector responses. The coordinated activation of STAT5 and STAT6 may have a major impact on monocyte alternative activation in vitro and in vivo. PMID:25824485

  3. Effect of glycolipids of Leishmania parasites on human monocyte activity. Inhibition by lipophosphoglycan.

    PubMed

    Frankenburg, S; Leibovici, V; Mansbach, N; Turco, S J; Rosen, G

    1990-12-15

    Lipophosphoglycan (LPG) and glycosyl phosphatidylinositol Ag (GPI), are glycolipids present on the membrane of Leishmania parasites. Both glycolipids have been chemically characterized. LPG is a polysaccharide of repeating phosphorylated units linked to a phosphocarbohydrate core that is anchored to the membrane by lysoalkyl phosphatidylinositol (PI). The GPI are smaller glycolipids with a structure resembling the phosphocarbohydrate core of the LPG. They are anchored to the membrane by alkyl acyl PI. Their relative abundance, uniqueness of structure, and cellular location suggest a role in interactions of the parasites with host cells. In the present study we examined the effect of LPG and GPI on the activation of human peripheral blood monocytes. Three parameters were studied: the production of IL-1, chemotactic locomotion, and oxidative burst. We found that whereas neither GPI nor LPG directly affected monocyte activity, preincubation of the monocytes with LPG strongly inhibited further activation: The production of IL-1, after stimulation with LPS, was decreased in a dose-dependent manner. Previous incubation with LPG also inhibited chemotactic locomotion of monocytes and neutrophils in response to diacylglycerol, zymosan-activated serum, FMLP and LTB4. Luminol-dependent chemiluminiscence caused by stimulation of the monocytes with streptococci and histone was also inhibited. After fragmentation of the LPG into phosphoglycan and 1-O-alkylglycerol by phosphatidylinositol-phospholipase C, only the phosphoglycan retained inhibitory activity. No difference in inhibitory activity was found between LPG prepared from Leishmania major or Leishmania donovani promastigotes. These results show that the phosphoglycan of LPG inhibits the immunologic response of normal human monocytes and neutrophils, and suggest that LPG may influence the nature of the inflammatory response surrounding infected cells. PMID:2147940

  4. Localized adhesion of monocytes to human atherosclerotic plaques demonstrated in vitro: implications for atherogenesis.

    PubMed Central

    Poston, R. N.; Johnson-Tidey, R. R.

    1996-01-01

    Blood-derived macrophages in the arterial intima are a characteristic feature of active atherosclerotic plaques. Adherent monocytes on the luminal surface and increased adhesion molecules on the endothelium have suggested that specific molecular mechanisms are involved in monocyte/macrophage traffic into the arterial wall. Adhesion of human monocytes and related cell lines was therefore studied in vitro to histological sections of human plaques. At 37 degrees C, these cells bound selectively to the plaques. Binding to the endothelium occurred and was also present extensively in the diseased intima. Inhibition studies showed that the endothelial and general intimal binding had largely similar molecular properties. Strong inhibition was produced by antibodies to the monocyte-specific adhesion molecule CD14, to beta2 integrins, and to ICAM-1. Likewise, a peptide containing the Arg-Gly-Asp sequence was strongly inhibitory, suggesting that binding of leukocyte integrins to arterial extracellular matrix was synergistic with cell-cell interactions. A P-selectin antibody was exceptional in giving selective inhibition of endothelial adhesion, which correlates with the specific endothelial localization of this adhesion molecule. These results show that monocytes adhere to atherosclerotic plaques through the focal activation of multiple arterial wall adhesion molecules, confirming the adhesion hypothesis. A positive feedback theory for the pathogenesis of atherosclerosis can be suggested, based on the ability of macrophages in the wall to activate the endothelium, induce adhesion molecules, and facilitate additional monocyte entry. The adhesion assay provides a means for the identification of adhesion inhibitors with therapeutic potential. Images Figure 2 PMID:8686764

  5. Human immunodeficiency virus glycoprotein (gp120) induction of monocyte arachidonic acid metabolites and interleukin 1.

    PubMed Central

    Wahl, L M; Corcoran, M L; Pyle, S W; Arthur, L O; Harel-Bellan, A; Farrar, W L

    1989-01-01

    This study reports on the direct effect of the envelope glycoprotein (gp120) of the human immunodeficiency virus type 1 (HIV-1) on human monocyte function. Addition of preparations of purified gp120 from the HIV-1 to human monocytes resulted in the production of interleukin 1 (IL-1) and arachidonic acid metabolites from the cyclooxygenase and lipoxygenase pathways. Quantification of prostaglandin E2 (PGE2) and IL-1 revealed an increase in both mediators with 50 ng of gp120 per ml and an increase of 12- and 30- to 40-fold with 200-400 ng of gp120 per ml, respectively. Unlike native gp120, the recombinant nonglycosylated gp120 fragments PB1-RF and PB1-IIIB, as well as one of the core structural proteins of HIV-1, p24, did not increase arachidonic acid metabolism or IL-1 activity. Cytofluorometric analysis revealed that gp120 blocked the binding of OKT4A to the CD4 on monocytes, whereas OKT4 binding was unaffected. Involvement of the CD4 in signal transduction was further demonstrated by the ability of OKT4 and OKT4A monoclonal antibodies to increase monocyte PGE2, IL-1 activity, and nanogram amounts of IL-1 beta. PMID:2536171

  6. Induction of release of tumor necrosis factor from human monocytes by staphylococci and staphylococcal peptidoglycans.

    PubMed Central

    Timmerman, C P; Mattsson, E; Martinez-Martinez, L; De Graaf, L; Van Strijp, J A; Verbrugh, H A; Verhoef, J; Fleer, A

    1993-01-01

    The role of cytokines in gram-positive infections is still relatively poorly defined. The purpose of this study was to establish whether or not intact staphylococci and purified peptidoglycans and peptidoglycan components derived from staphylococci are capable of stimulating the release of tumor necrosis factor (TNF) by human monocytes. We show here that intact staphylococci and purified peptidoglycans, isolated from three Staphylococcus epidermidis and three S. aureus strains, were indeed able to induce secretion of TNF by human monocytes in a concentration-dependent fashion. TNF release was detected by both enzyme immunoassay and the L929 fibroblast bioassay. In the enzyme immunoassay, a minimal concentration of peptidoglycan of 1 micrograms/ml was required to detect TNF release by monocytes, whereas in the bioassay a peptidoglycan concentration of 10 micrograms/ml was needed to detect a similar amount of TNF release. Peptidoglycan components such as the stem peptide, tetra- and pentaglycine, and muramyl dipeptide were unable to induce TNF release from human monocytes. PMID:8406805

  7. Lipopolysaccharide induces autotaxin expression in human monocytic THP-1 cells

    SciTech Connect

    Li Song; Zhang Junjie

    2009-01-09

    Autotaxin (ATX) is a secreted enzyme with lysophospholipase D (lysoPLD) activity, which converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive phospholipid involved in numerous biological activities, including cell proliferation, differentiation, and migration. In the present study, we found that bacterial lipopolysaccharide (LPS), a well-known initiator of the inflammatory response, induced ATX expression in monocytic THP-1 cells. The activation of PKR, JNK, and p38 MAPK was required for the ATX induction. The LPS-induced ATX in THP-1 cells was characterized as the {beta} isoform. In the presence of LPC, ATX could promote the migrations of THP-1 and Jurkat cells, which was inhibited by pertussis toxin (PTX), an inhibitor of Gi-mediated LPA receptor signaling. In summary, LPS induces ATX expression in THP-1 cells via a PKR, JNK and p38 MAPK-mediated mechanism, and the ATX induction is likely to enhance immune cell migration in proinflammatory response by regulating LPA levels in the microenvironment.

  8. Baseline Gene Expression Signatures in Monocytes from Multiple Sclerosis Patients Treated with Interferon-beta

    PubMed Central

    Bustamante, Marta F.; Nurtdinov, Ramil N.; Río, Jordi; Montalban, Xavier; Comabella, Manuel

    2013-01-01

    Background A relatively large proportion of relapsing-remitting multiple sclerosis (RRMS) patients do not respond to interferon-beta (IFNb) treatment. In previous studies with peripheral blood mononuclear cells (PBMC), we identified a subgroup of IFNb non-responders that was characterized by a baseline over-expression of type I IFN inducible genes. Additional mechanistic experiments carried out in IFNb non-responders suggested a selective alteration of the type I IFN signaling pathway in the population of blood monocytes. Here, we aimed (i) to investigate whether the type I IFN signaling pathway is up-regulated in isolated monocytes from IFNb non-responders at baseline; and (ii) to search for additional biological pathways in this cell population that may be implicated in the response to IFNb treatment. Methods Twenty RRMS patients classified according to their clinical response to IFNb treatment and 10 healthy controls were included in the study. Monocytes were purified from PBMC obtained before treatment by cell sorting and the gene expression profiling was determined with oligonucleotide microarrays. Results and discussion Purified monocytes from IFNb non-responders were characterized by an over-expression of type I IFN responsive genes, which confirms the type I IFN signature in monocytes suggested from previous studies. Other relevant signaling pathways that were up-regulated in IFNb non-responders were related with the mitochondrial function and processes such as protein synthesis and antigen presentation, and together with the type I IFN signaling pathway, may also be playing roles in the response to IFNb. PMID:23637780

  9. Human monocyte-derived dendritic cells turn into foamy dendritic cells with IL-17A.

    PubMed

    Salvatore, Giulia; Bernoud-Hubac, Nathalie; Bissay, Nathalie; Debard, Cyrille; Daira, Patricia; Meugnier, Emmanuelle; Proamer, Fabienne; Hanau, Daniel; Vidal, Hubert; Aricò, Maurizio; Delprat, Christine; Mahtouk, Karène

    2015-06-01

    Interleukin 17A (IL-17A) is a proinflammatory cytokine involved in the pathogenesis of chronic inflammatory diseases. In the field of immunometabolism, we have studied the impact of IL-17A on the lipid metabolism of human in vitro-generated monocyte-derived dendritic cells (DCs). Microarrays and lipidomic analysis revealed an intense remodeling of lipid metabolism induced by IL-17A in DCs. IL-17A increased 2-12 times the amounts of phospholipids, cholesterol, triglycerides, and cholesteryl esters in DCs. Palmitic (16:0), stearic (18:0), and oleic (18:ln-9c) acid were the main fatty acid chains present in DCs. They were strongly increased in response to IL-17A while their relative proportion remained unchanged. Capture of extracellular lipids was the major mechanism of lipid droplet accumulation, visualized by electron microscopy and Oil Red O staining. Besides this foamy phenotype, IL-17A induced a mixed macrophage-DC phenotype and expression of the nuclear receptor NR1H3/liver X receptor-α, previously identified in the context of atherosclerosis as the master regulator of cholesterol homeostasis in macrophages. These IL-17A-treated DCs were as competent as untreated DCs to stimulate allogeneic naive T-cell proliferation. Following this first characterization of lipid-rich DCs, we propose to call these IL-17A-dependent cells "foamy DCs" and discuss the possible existence of foamy DCs in atherosclerosis, a metabolic and inflammatory disorder involving IL-17A. PMID:25833686

  10. Monocytes increase human cardiac myofibroblast-mediated extracellular matrix remodeling through TGF-β1.

    PubMed

    Mewhort, Holly E M; Lipon, Brodie D; Svystonyuk, Daniyil A; Teng, Guoqi; Guzzardi, David G; Silva, Claudia; Yong, V Wee; Fedak, Paul W M

    2016-03-15

    Following myocardial infarction (MI), cardiac myofibroblasts remodel the extracellular matrix (ECM), preventing mechanical complications. However, prolonged myofibroblast activity leads to dysregulation of the ECM, maladaptive remodeling, fibrosis, and heart failure (HF). Chronic inflammation is believed to drive persistent myofibroblast activity; however, the mechanisms are unclear. We assessed the influence of peripheral blood monocytes on human cardiac myofibroblast activity in a three-dimensional (3D) ECM microenvironment. Human cardiac myofibroblasts isolated from surgical biopsies of the right atrium and left ventricle were seeded into 3D collagen matrices. Peripheral blood monocytes were isolated from healthy human donors and cocultured with myofibroblasts. Monocytes increased myofibroblast activity measured by collagen gel contraction (baseline: 57.6 ± 5.9% vs. coculture: 65.2 ± 7.1% contraction; P < 0.01) and increased local ECM remodeling quantified by confocal microscopy. Under coculture conditions that allow indirect cellular interaction via paracrine factors but prevent direct cell-cell contact, monocytes had minimal effects on myofibroblast activity (17.9 ± 11.1% vs. 6.4 ± 7.0% increase, respectively; P < 0.01). When cells were cultured under direct contact conditions, multiplex analysis of the coculture media revealed an increase in the paracrine factors TGF-β1 and matrix metalloproteinase 9 compared with baseline (122.9 ± 10.1 pg/ml and 3,496.0 ± 190.4 pg/ml, respectively, vs. 21.5 ± 16.3 pg/ml and 183.3 ± 43.9 pg/ml; P < 0.001). TGF-β blockade abolished the monocyte-induced increase in cardiac myofibroblast activity. These data suggest that direct cell-cell interaction between monocytes and cardiac myofibroblasts stimulates TGF-β-mediated myofibroblast activity and increases remodeling of local matrix. Peripheral blood monocyte interaction with human cardiac myofibroblasts stimulates myofibroblast activity through release of TGF-β1

  11. Phagocytosis and killing of Trypanosoma dionisii by human neutrophils, eosinophils and monocytes.

    PubMed

    Thorne, K J; Glauert, A M; Svvennsen, R J; Franks, D

    1979-12-01

    The cell-mediated resistance of human leucocytes to Trypanosoma dionisii, a bat parasite related to T. cruzi, was investigated. Human peripheral blood neutrophils and monocytes were cytotoxic to T. dionisii as assessed by electron microscopy and by induction of 99mTc release from trypanosomes pre-labelled with [99mTc] pertechnetate. The enhancement of cytotoxicity by specific antiserum varied considerably from one individual to another. Neither blood lymphocytes nor blood eosinophils induced 99mTc release from T. dionisii. The trypanosomes were readily phagocytosed by neutrophils and monocytes even in the absence of added antiserum but the rate was enchanced when antiserum was present. Eosinophils also phagocytosed T. dionisii but only in the presence of antiserum. Investigation by electron microscopy revealed that T. dionisii is rapidly destroyed in the phagocytic vacuole of enutrophils and monocytes and by eosinophils. Phagocytosis, ultrastructural damage and induction of 99mTc release occurred more rapidly in neutrophils than in monocytes. PMID:542324

  12. Mycobacterial growth and sensitivity to H2O2 killing in human monocytes in vitro.

    PubMed Central

    Laochumroonvorapong, P; Paul, S; Manca, C; Freedman, V H; Kaplan, G

    1997-01-01

    The intracellular growth and susceptibilities to killing by H2O2 in cultured human monocytes of a number of mycobacterial species including laboratory strains and clinical isolates of Mycobacterium tuberculosis, and Mycobacterium bovis bacillus Calmette-Guerin (BCG) and a clinical isolate of Mycobacterium avium-M. intracellulare were examined. The clinical isolate of M. avium-M. intracellulare did not replicate in freshly explanted monocytes (generation time of >400 h); BCG replicated with a generation time of 95 h, and M. tuberculosis strains CDC551, H37Rv, and H37Ra replicated with generation times of 24, 35, and 37 h, respectively, during the 4-day growth assay. When cultured in monocytes for 4 days, the mycobacteria were variably sensitive to H2O2-induced killing. A positive correlation between the generation time and percent killing of intracellular bacilli was observed. By comparison, mycobacterial strains were similarly sensitive to H2O2 treatment in cell-free culture media and in sonicated cell suspensions. Using a number of inhibitors of reactive oxygen intermediates we determined that other than catalase the inhibitors tested did not affect H2O2-induced killing of intracellular mycobacteria. Our studies suggest that the killing of mycobacteria growing in human monocytes in vitro by the addition of exogenous H2O2 is dependent on the susceptibility to a peroxide-induced killing pathway as well as on the intracellular growth rate of the mycobacteria. PMID:9353075

  13. Biological effects of double-walled carbon nanotubes on the innate immune system: An in vitro study on THP-1 human monocytes.

    PubMed

    Dekali, Samir; Bachelet, Christine; Maunoir-Regimbal, Séverine; Flahaut, Emmanuel; Debouzy, Jean-Claude; Crouzier, David

    2016-07-15

    DWCNTs have numerous industrial and biomedical applications and several studies reported that they could act as immunomodulator systems. The immune system is the first line of defence of the human body when exposed to particulate matter. In order to investigate DWCNTs' role on innate immunity, we used THP-1 monocytic cells for the purpose of this study. We showed that DWCNTs were not cytotoxic until 6h, 24h, 48h and 72h of incubation with THP-1 monocytic cells (concentrations tested from 10 to 50μg/mL). From 6h to 72h of incubation of THP-1 cells with DWCNTs, we measured a significant increase of the baseline cell index using xCELLigence(®) technology showing cell adhesion. After 24h of exposure, DWCNTs agglomerates were localized in THP-1 monocyte cytoplasm and cell adhesion was observed simultaneously with a significant increase in the expression of CD11b and CD14 cell surface proteins. Pro-inflammatory cytokine secretion (IL-1β, IL-6, IL-8, TNF-α and IL-10) was also measured in supernatants after 6h or 24h of exposure to DWCNTs. This pro-inflammatory response was increased in THP-1 monocytic cells pre-treated with LPS. Altogether, our data indicate that DWCNTs induce an increased pro-inflammatory response of THP-1 monocytes and seem to modulate cell surface protein expression confirming that DWCNTs could act as stimulators of innate immunity. PMID:27475286

  14. Human monocytes and macrophages undergo M1-type inflammatory polarization in response to high levels of glucose.

    PubMed

    Torres-Castro, Israel; Arroyo-Camarena, Úrsula D; Martínez-Reyes, Camilo P; Gómez-Arauz, Angélica Y; Dueñas-Andrade, Yareth; Hernández-Ruiz, Joselín; Béjar, Yadira L; Zaga-Clavellina, Verónica; Morales-Montor, Jorge; Terrazas, Luis I; Kzhyshkowska, Julia; Escobedo, Galileo

    2016-08-01

    Emerging data suggest that elevated glucose may promote inflammatory activation of monocytic lineage cells with the ability to injure vascular endothelial tissue of diabetic patients, however evidence in primary human monocytes and macrophages is still insufficient. We investigated the effect of high glucose concentration on the inflammatory capacity of human macrophages in vitro and examined whether similar responses were detectable in circulating monocytes from prediabetic patients. Primary monocytes were isolated from healthy blood donors and differentiated into macrophages. Differentiated macrophages were exposed to normal levels of glucose (NG), high glucose (HG) or high mannitol as osmotic pressure control (OP) for three days. Using PCR, ELISA and flow cytometry, we found that HG macrophages showed overexpression of CD11c and inducible nitric oxide synthase as well as down-regulation of arginase-1 and interleukin (IL)-10 with respect to NG and OP macrophages. Consistent with in vitro results, circulating monocytes from hyperglycemic patients exhibited higher levels of CD11c and lower expression of CD206 than monocytes from normoglycemic controls. In subjects with hyperglycemia, elevation in CD11c(+) monocytes was associated with increased obesity, insulin resistance, and triglyceridemia as well as low serum IL-10. Our data suggest that human monocytes and macrophages undergo M1-like inflammatory polarization when exposed to high levels of glucose on in vitro culture conditions and in patients with hyperglycemia. These results demonstrate that excess glucose has direct effects on macrophage activation though the molecular mechanisms mediating such a response remain to be elucidated. PMID:27269375

  15. Alcohol-Induced miR-27a Regulates Differentiation and M2 Macrophage Polarization of Normal Human Monocytes

    PubMed Central

    Saha, Banishree; Bruneau, Johanna C.; Kodys, Karen; Szabo, Gyongyi

    2015-01-01

    Alcohol abuse is a leading cause of liver disease characterized by liver inflammation, fatty liver, alcoholic hepatitis, or liver cirrhosis. Immunomodulatory effects of alcohol on monocytes and macrophages contribute to alcoholic liver disease. Alcohol use, an independent risk factor for progression of hepatitis C virus (HCV) infection–mediated liver disease, impairs host defense and alters cytokine production and monocyte/macrophage activation. We hypothesized that alcohol and HCV have synergistic effects on the phenotype and function of monocytes. Our data show that acute alcohol binge drinking in healthy volunteers results in increased frequency of CD16+ and CD68+ and M2-type (CD206+, dendritic cell [DC]-SIGN+–expressing and IL-10–secreting) circulating CD14+ monocytes. Expression of HCV-induced CD68 and M2 markers (CD206 and DC-SIGN) in normal monocytes was further enhanced in the presence of alcohol. The levels of microRNA (miR)-27a was significantly upregulated in monocytes cultured in the presence of alcohol or alcohol and HCV as compared with HCV alone. The functional role of miR-27a in macrophage polarization was demonstrated by transfecting monocytes with an miR-27a inhibitor that resulted in reduced alcohol- and HCV- mediated monocyte activation (CD14 and CD68 expression), polarization (CD206 and DC-SIGN expression), and IL-10 secretion. Over-expression of miR-27a in monocytes enhanced IL-10 secretion via activation of the ERK signaling pathway. We found that miR-27a promoted ERK phosphorylation by downregulating the expression of ERK inhibitor sprouty2 in monocytes. Thus, we identified that sprouty2 is a target of miR-27a in human monocytes. In summary, our study demonstrates the regulatory role of miR-27a in alcohol-induced monocyte activation and polarization. PMID:25716995

  16. Differential response of human monocytes to Neisseria gonorrhoeae variants expressing pili and opacity proteins.

    PubMed Central

    Knepper, B; Heuer, I; Meyer, T F; van Putten, J P

    1997-01-01

    Experiments in vitro suggest that Neisseria gonorrhoeae surface variation plays a key role in gonococcal pathogenesis by providing the appropriate bacterial phenotypes to go through different stages of the infection. Here we report on the effects of phase and antigen variation of two major gonococcal adhesins, pili and opacity (Opa) outer membrane proteins, on the interaction of the gonococci with human monocytes. Using a set of recombinants of gonococcus strain MS11 that each express 1 of 11 genetically defined Opa proteins or a defined type of pilus, we found that both Opa proteins and pili promote bacterial phagocytosis by monocytes in the absence of serum and that this feature largely depends on the type of protein that is expressed. One of the Opa proteins (Opa[50]) strongly promoted uptake by monocytes but had little effect on the interaction with polymorphonuclear leukocytes under the conditions employed. Similarly, the phagocytosis-promoting effect of the pili was much more pronounced in monocytes than in neutrophils (4-fold versus 22-fold stimulation of uptake, respectively). Only a subpopulation of both types of phagocytes actively ingested bacteria, as has been observed during natural infections. Measurements of luminol-enhanced chemiluminescence demonstrated that phagocytosis of opaque but not piliated gonococci was accompanied by an increase in oxygen-reactive metabolites. These findings demonstrate that the monocyte response towards gonococci is highly dependent on the bacterial phenotype and differs from the neutrophil response. This diversity in bacterial behavior towards various types of human phagocytic cells underlines the biological impact of gonococcal surface variation and may explain previous contradictory results on this subject. PMID:9317017

  17. Lymphocyte-conditioned medium protects human monocyte-macrophages from cholesteryl ester accumulation.

    PubMed Central

    Fogelman, A M; Seager, J; Haberland, M E; Hokom, M; Tanaka, R; Edwards, P A

    1982-01-01

    Exposure of human monocyte-macrophages to as little as 50 microliters of cultured medium from lymphocytes stimulated by concanavalin A (Con A) resulted in a dramatic decrease in the activities of the low density lipoprotein (LDL) receptor pathway, the LDL-dextran sulfate pathway, and the scavenger receptor pathway. This effect was not seen when the monocyte-macrophages were exposed to culture medium from lymphocytes cultured without Con A or with Con A together with alpha-methyl mannoside or control medium without lymphocytes. The activity of 3-hydroxy-3-methyglutaryl-coenzyme A reductase also decreased in monocyte-macrophages exposed to culture medium from stimulated lymphocytes. Acyl-CoA:cholesterol O-acyltransferase activity, protein synthesis, protein content, phagocytosis of heat-killed yeast, and non-receptor-mediated endocytosis were not inhibited. Monocyte-macrophages exposed to malondialdehyde altered-LDL in the presence of stimulated lymphocyte culture medium accumulated substantially less cholesteryl esters than did cells in control medium. We propose that substances produced by stimulated lymphocytes may be useful in protecting macrophages from cholesteryl ester accumulation. Images PMID:6278500

  18. Human antiphospholipid antibodies induce TNFalpha in monocytes via Toll-like receptor 8.

    PubMed

    Döring, Yvonne; Hurst, Julia; Lorenz, Mareike; Prinz, Nadine; Clemens, Natascha; Drechsler, Maik D; Bauer, Stefan; Chapman, Joab; Shoenfeld, Yehuda; Blank, Miri; Lackner, Karl J; von Landenberg, Philipp

    2010-03-01

    The antiphospholipid syndrome (APS) is characterized by recurrent arterial and/or venous thromboses, pregnancy loss and the presence of antiphospholipid antibodies (aPL). One of the discussed mechanisms of this thrombotic activity in APS patients is attributed to TNFalpha secretion in monocytes after aPL stimulation. To investigate this mechanism in detail, we employed a monoclonal aPL and IgG fractions of APS patients for stimulation of human peripheral monocytes. Stimulation with this monoclonal aPL resulted in an increased expression and secretion of TNFalpha, caused by specific upregulation of TLR8 mRNA and protein expression levels. To confirm the specificity of this finding we could demonstrate that the TNFalpha enhancement could be neutralized by a TLR8-specific inhibitory DNA-oligonucleotide and could be further increased by adding the specific ligands for TLR8. Using APS patients IgG fractions for stimulation of peripheral monocytes revealed a similar TLR8 mRNA elevation and increase in TNFalpha-production. Furthermore the TLR8 expression level in PBMC's of APS patients was as well significantly elevated. It could be demonstrated that the TNFalpha release in monocytes resulting from aPL stimulation was exclusively induced by TLR8 engagement. This could be confirmed in PBMC's of APS patients, hinting that endogenous stimulation of TLR8 in APS patients and consecutive elevation of TNFalpha promotes a proinflammatory environment. PMID:19457574

  19. Actinobacillus actinomycetemcomitans serotype b-specific polysaccharide antigen stimulates production of chemotactic factors and inflammatory cytokines by human monocytes.

    PubMed Central

    Yamaguchi, N; Yamashita, Y; Ikeda, D; Koga, T

    1996-01-01

    Serotype b-specific polysaccharide antigen (SPA) was extracted from whole cells of Actinobacillus actinomycetemcomitans Y4 by autoclaving and purified by chromatography on DEAE-Sephadex A-25 and Sephacryl S-300. SPA induced the release of monocyte and leukocyte chemotactic factors by human monocytes. Polymyxin B had almost no effect on the release of monocyte chemotactic factor, but a monoclonal antibody against SPA markedly inhibited it. Human monocytes stimulated with SPA exhibited the increased mRNA expression of monocyte chemoattractant protein 1 (MCP-1) and a neutrophil chemotactic factor, interleukin-8 (IL-8). On the other hand, SPA induced the release of IL-1, IL-6, and tumor necrosis factor (TNF) and enhanced the expression of IL-1alpha, IL-1beta, IL-6, and TNF alpha (TNF-alpha) mRNAs. Human monocytes expressed MCP-1 and IL-8 mRNAs when stimulated by human recombinant IL-1alpha, I1-1beta, IL-6, and TNF-alpha, suggesting that these inflammatory cytokines induced by SPA might participate in the production of chemotactic factors in human monocytes. PMID:8698480

  20. Differentiation of human monocytes and derived subsets of macrophages and dendritic cells by the HLDA10 monoclonal antibody panel

    PubMed Central

    Ohradanova-Repic, Anna; Machacek, Christian; Fischer, Michael B; Stockinger, Hannes

    2016-01-01

    The mononuclear phagocyte system, consisting of monocytes, macrophages and dendritic cells (DCs), has an important role in tissue homeostasis as well as in eliciting immune responses against invading pathogens. Blood monocytes have been viewed for decades as precursors of tissue macrophages. Although the newest data show that in the steady state resident macrophages of many organs are monocyte independent, blood monocytes critically contribute to tissue macrophage and DC pools upon inflammation. To better understand the relationship between these populations and their phenotype, we isolated and differentiated human blood CD14+ monocytes in vitro into immature and mature monocyte-derived dendritic cells (MoDCs) as well as into seven different monocyte-derived macrophage subsets. We used the panel of 70 monoclonal antibodies (mAbs) submitted to the 10th Human Leukocyte Differentiation Antigen Workshop to determine the expression profiles of these 10 populations by flow cytometry. We now can compile subpanels of mAbs to differentiate the 10 monocyte/macrophage/MoDC subsets, providing the basis for novel diagnostic and therapeutic tools. PMID:26900469

  1. Dharmendra antigen but not integral M. leprae is an efficient inducer of immunostimulant cytokine production by human monocytes, and M. leprae lipids inhibit the cytokine production.

    PubMed

    Nakamura, C; Fukutomi, Y; Kashiwabara, Y; Oomoto, Y; Kojima, M; Hayashi, H; Onozaki, K

    1997-03-01

    Killed integral Mycobacterium leprae, Mitsuda antigen, and chloroform-treated M. leprae, Dharmendra antigen (Dh-Ag), have been used for the classification of leprosy patients based on cell-mediated immunity. Heat-killed M. leprae also were used as a component of the Convit vaccine. Human blood monocytes were stimulated with M. leprae or Dh-Ag and their cytokine-inducing ability was compared. Monocytes were cultured in the presence of fresh human serum because of the efficiency of cytokine induction and the phagocytosis of M. leprae have been shown to be optimal in the presence of fresh serum. M. leprae and Dh-Ag were equally phagocytosed by monocytes. Dh-Ag was more potent than M. leprae in the induction of immunostimulatory/proinflammatory cytokines, interleukin-1 (IL-1), IL-6 and tumor necrosis factor (TNF). In contrast, a comparable level of IL-1ra, an immunosuppressive cytokine, was induced by M. leprae and Dh-Ag. The lipids extracted from M. leprae induced none of these cytokines by monocytes. Nevertheless, when monocytes were pretreated with the lipids followed by stimulation with Dh-Ag, productions of IL-1, IL-6 and TNF were all inhibited in a dose-dependent manner. However, the lipids did not inhibit the cytokine production induced by other stimuli including BCG and lipopolysaccharide. Moreover the lipids did not affect the production of IL-1ra. These results suggest that the lipids from M. leprae are responsible for the poor cytokine-inducing ability of M. leprae, thus favoring their infection. These results also suggest that Dh-Ag rather than integral M. leprae may be useful as a vaccine candidate because Dh-Ag is able to induce a large amount of cytokines from monocytes. PMID:9207755

  2. Monocyte chemotactic protein-1 (MCP-1), -2, and -3 are chemotactic for human T lymphocytes.

    PubMed Central

    Taub, D D; Proost, P; Murphy, W J; Anver, M; Longo, D L; van Damme, J; Oppenheim, J J

    1995-01-01

    Monocyte chemotactic protein (MCP)-1, -2, and -3 all have been shown to induce monocyte/macrophage migration in vitro and MCP-1, also known as MCAF, chemoattracts basophils and mast cells. We report here that natural MCP-1 as well as synthetic preparations of MCP-2 and MCP-3 stimulate significant in vitro chemotaxis of human peripheral blood T lymphocytes. This MCP-induced migration was dose-dependent and directional, but not chemokinetic. Phenotypic analysis of the T cell population responsive to MCP-1, MCP-2, and MCP-3 demonstrates that both CD4+ and CD8+ T cells migrated in response to these chemokines. Similar results were observed using human CD4+ and CD8+ T cell clones. Neutralizing antisera to MCAF or MCP-2 abrogated T cell migration in response to MCP-1 and MCP-2, respectively, but not to RANTES. Subcutaneous administration of purified MCP-1 into the hind flanks of SCID mice engrafted with human peripheral blood lymphocytes (PBL) induced significant human CD3+ T cell infiltration into the site of injection at 4 h. These results demonstrate that MCP-1, MCP-2, and MCP-3 are inflammatory mediators that specifically stimulate the directional migration of T cells as well as monocytes and may play an important role in immune cell recruitment into sites of antigenic challenge. Images PMID:7883984

  3. The effect of short-chain fatty acids on human monocyte-derived dendritic cells.

    PubMed

    Nastasi, Claudia; Candela, Marco; Bonefeld, Charlotte Menné; Geisler, Carsten; Hansen, Morten; Krejsgaard, Thorbjørn; Biagi, Elena; Andersen, Mads Hald; Brigidi, Patrizia; Ødum, Niels; Litman, Thomas; Woetmann, Anders

    2015-01-01

    The gut microbiota is essential for human health and plays an important role in the pathogenesis of several diseases. Short-chain fatty acids (SCFA), such as acetate, butyrate and propionate, are end-products of microbial fermentation of macronutrients that distribute systemically via the blood. The aim of this study was to investigate the transcriptional response of immature and LPS-matured human monocyte-derived DC to SCFA. Our data revealed distinct effects exerted by each individual SCFA on gene expression in human monocyte-derived DC, especially in the mature ones. Acetate only exerted negligible effects, while both butyrate and propionate strongly modulated gene expression in both immature and mature human monocyte-derived DC. An Ingenuity pathway analysis based on the differentially expressed genes suggested that propionate and butyrate modulate leukocyte trafficking, as SCFA strongly reduced the release of several pro-inflammatory chemokines including CCL3, CCL4, CCL5, CXCL9, CXCL10, and CXCL11. Additionally, butyrate and propionate inhibited the expression of lipopolysaccharide (LPS)-induced cytokines such as IL-6 and IL-12p40 showing a strong anti-inflammatory effect. This work illustrates that bacterial metabolites far from the site of their production can differentially modulate the inflammatory response and generally provides new insights into host-microbiome interactions. PMID:26541096

  4. Alcohol and Cannabinoids Differentially Affect HIV Infection and Function of Human Monocyte-Derived Dendritic Cells (MDDC)

    PubMed Central

    Agudelo, Marisela; Figueroa, Gloria; Yndart, Adriana; Casteleiro, Gianna; Muñoz, Karla; Samikkannu, Thangavel; Atluri, Venkata; Nair, Madhavan P.

    2015-01-01

    During human immunodeficiency virus (HIV) infection, alcohol has been known to induce inflammation while cannabinoids have been shown to have an anti-inflammatory role. For instance cannabinoids have been shown to reduce susceptibility to HIV-1 infection and attenuate HIV replication in macrophages. Recently, we demonstrated that alcohol induces cannabinoid receptors and regulates cytokine production by monocyte-derived dendritic cells (MDDC). However, the ability of alcohol and cannabinoids to alter MDDC function during HIV infection has not been clearly elucidated yet. In order to study the potential impact of alcohol and cannabinoids on differentiated MDDC infected with HIV, monocytes were cultured for 7 days with GM-CSF and IL-4, differentiated MDDC were infected with HIV-1Ba-L and treated with EtOH (0.1 and 0.2%), THC (5 and 10 μM), or JWH-015 (5 and 10 μM) for 4–7 days. HIV infection of MDDC was confirmed by p24 and Long Terminal Repeats (LTR) estimation. MDDC endocytosis assay and cytokine array profiles were measured to investigate the effects of HIV and substances of abuse on MDDC function. Our results show the HIV + EtOH treated MDDC had the highest levels of p24 production and expression when compared with the HIV positive controls and the cannabinoid treated cells. Although both cannabinoids, THC and JWH-015 had lower levels of p24 production and expression, the HIV + JWH-015 treated MDDC had the lowest levels of p24 when compared to the HIV + THC treated cells. In addition, MDDC endocytic function and cytokine production were also differentially altered after alcohol and cannabinoid treatments. Our results show a differential effect of alcohol and cannabinoids, which may provide insights into the divergent inflammatory role of alcohol and cannabinoids to modulate MDDC function in the context of HIV infection. PMID:26733986

  5. Specific binding of soluble peptidoglycan and muramyldipeptide to CD14 on human monocytes.

    PubMed Central

    Weidemann, B; Schletter, J; Dziarski, R; Kusumoto, S; Stelter, F; Rietschel, E T; Flad, H D; Ulmer, A J

    1997-01-01

    Previously, we were able to show that soluble peptidoglycan (sPG)-induced monokine production in human peripheral monocytes is inhibited by anti-CD14 monoclonal antibodies and by lipid A partial structures. This suggested but did not prove that monocytic surface protein CD14 is involved in the activation of human monocytes not only by cell wall components of gram-negative bacteria such as lipopolysaccharide (LPS) but also by cell wall components of gram-positive bacteria such as sPG. In the present study, we provide experimental evidence that CD14 indeed constitutes a binding site for sPG recognition and activation of human monocytes. The results show that fluorescein isothiocyanate-sPG (FITC-sPG) binds to human monocytes in a saturable, dose-dependent, and specific manner. For maximal binding, 2 to 3 microg of FITC-sPG per ml was sufficient, and this binding is completed within 90 min; about 40% of the binding is completed within the first 3 min. The FITC-sPG binding is considered specific because unlabeled sPG and also muramyldipeptide (MDP), the minimal bioactive structure of sPG, inhibit the binding of sPG to monocytes in a dose-dependent manner. This specific binding was also inhibited by an anti-CD14 monoclonal antibody, LPS, and lipid A partial structure compound 406. Direct evidence for an interaction of sPG with CD14 is provided by experiments involving native polyacrylamide gel electrophoresis that showed a shift of the electrophoretic mobility of CD14 by LPS as well as by sPG. These results allow the conclusion that sPG binds directly to CD14, that MDP represents the active substructure of sPG, and that CD14 may be a lectin-like receptor which plays a key role in cellular stimulation by bioactive components of not only gram-negative but also gram-positive bacteria. PMID:9038288

  6. Expression of extracellular calcium (Ca2+o)-sensing receptor in human peripheral blood monocytes

    NASA Technical Reports Server (NTRS)

    Yamaguchi, T.; Olozak, I.; Chattopadhyay, N.; Butters, R. R.; Kifor, O.; Scadden, D. T.; Brown, E. M.; O'Malley, B. W. (Principal Investigator)

    1998-01-01

    The calcium-sensing receptor (CaR) is a G protein-coupled receptor playing key roles in extracellular calcium ion (Ca2+o) homeostasis in parathyroid gland and kidney. Macrophage-like mononuclear cells appear at sites of osteoclastic bone resorption during bone turnover and may play a role in the "reversal" phase of skeletal remodeling that follows osteoclastic resorption and precedes osteoblastic bone formation. Bone resorption produces substantial local increases in Ca2+o that could provide a signal for such mononuclear cells present locally within the bone marrow microenvironment. Indeed, previous studies by other investigators have shown that raising Ca2+o either in vivo or in vitro stimulated the release of interleukin-6 (IL-6) from human peripheral blood monocytes, suggesting that these cells express a Ca2+o-sensing mechanism. In these earlier studies, however, the use of reverse transcription-polymerase chain reaction (RT-PCR) failed to detect transcripts for the CaR previously cloned from parathyroid and kidney in peripheral blood monocytes. Since we recently found that non-specific esterase-positive, putative monocytes isolated from murine bone marrow express the CaR, we reevaluated the expression of this receptor in human peripheral blood monocytes. Immunocytochemistry, flow cytometry, and Western blot analysis, performed using a polyclonal antiserum specific for the CaR, detected CaR protein in human monocytes. In addition, the use of RT-PCR with CaR-specific primers, followed by nucleotide sequencing of the amplified products, identified CaR transcripts in the cells. Therefore, taken together, our data show that human peripheral blood monocytes possess both CaR protein and mRNA very similar if not identical to those expressed in parathyroid and kidney that could mediate the previously described, direct effects of Ca2+o on these cells. Furthermore, since mononuclear cells isolated from bone marrow also express the CaR, the latter might play some role in

  7. Lactate production by human monocytes/macrophages determined by proton MR spectroscopy.

    PubMed

    López-Villegas, D; Lenkinski, R E; Wehrli, S L; Ho, W Z; Douglas, S D

    1995-07-01

    Elevated brain lactate has been observed by in vivo proton MRS in different pathological situations. The origin of this lactate remains controversial. The possibility that it was produced by the metabolism of phagocytic cells has been proposed. To investigate this hypothesis, the authors have employed high-resolution proton MRS to monitor changes in glucose, lactate, and other metabolites in the medium used to culture human monocyte-derived macrophages in vitro. Results show that the differentiation of human monocytes/macrophages in the presence of physiological stimulating factors (M-CSF or GM-CSF) was associated with an increase in lactate production and glucose utilization. The present results are consistent with the hypothesis that lactate detected by proton MRS in vivo may be produced by the metabolism of macrophages when infiltrates of these cells are present. The possible extrapolation of the authors' finding to the in vivo situation and its relevance are discussed. PMID:7674895

  8. Rhizoctonia bataticola lectin (RBL) induces phenotypic and functional characteristics of macrophages in THP-1 cells and human monocytes.

    PubMed

    Pujari, Radha; Kumar, Natesh; Ballal, Suhas; Eligar, Sachin M; Anupama, S; Bhat, Ganapati; Swamy, Bale M; Inamdar, Shashikala R; Shastry, Padma

    2015-02-01

    We have previously reported that a fungal lectin, Rhizoctonia bataticola lectin (RBL), stimulates proliferation and secretion of Th1/Th2 cytokines in human peripheral blood mononuclear cells (PBMC). In the present study, we evaluated the ability of RBL to differentiate human monocytes to macrophages. RBL induced morphological changes indicative of differentiation in primary monocytes and THP-1 cells. Stimulation with RBL resulted in significant up-regulation of differentiation markers - CD54, HLA-DR, CD11b and CD11c and secretion of proinflammatory cytokines - IL-1β, TNF-α and IL-6. Functionally, RBL profoundly increased phagocytic activity in monocytes. In THP-1 cells, RBL-induced phagocytosis was higher compared to the effect induced by combination of phorbol-12-myristate-13-acetate (PMA) and lipopolysaccharide (LPS). RBL induced a significant increase in matrix metalloproteinase-9 (MMP-9) activity in comparison with a combined treatment of PMA+LPS. Mechanistic studies revealed the involvement of the NF-κB pathway in RBL-induced differentiation of monocytes. The data suggest that RBL mimics the combined action of PMA and LPS to induce morphological and functional differentiation in human monocytes and monocytic cell line - THP-1 to macrophages. Human monocytes differentiated to macrophages with RBL have the potential as an in vitro model to study macrophage biology. PMID:25555439

  9. Dexamethasone -induced apoptosis of human monocytes exposed to immune complexes. Intervention of CD95- and XIAP-dependent pathways.

    PubMed

    Ottonello, L; Bertolotto, M; Montecucco, F; Dapino, P; Dallegri, F

    2005-01-01

    Monocytes and macrophages play a key role in the initiation and persistence of inflammatory reactions. The possibility to interfere with the survival of these cells, once recruited and activated at sites of inflammation, is an attractive therapeutic option. Although resting monocytes are susceptible to pharmacologically induced apoptosis, no data are available about the possibility to modulate the survival of activated monocytes. The present work was planned to investigate if dexamethasone is able to promote apoptosis of human monocytes activated by immune complexes. When monocytes were cultured with immune complexes, a dose-dependent inhibition of apoptosis was observed. Dexamethasone stimulated apoptosis of resting and activated monocytes in a dose-dependent manner. Both the immune complex inhibitory activity and dexamethasone stimulatory properties depend on NF-kappaB/XIAP and Ras/MEK/ERK/CD95 pathways. In fact, the exposure of monocytes to immune complexes increased NF-kB activation and XIAP expression, which in turn were inhibited by dexamethasone. On the other hand, immune complex-stimulated monocytes displayed a reduced expression of CD95, which is prevented by dexamethasone, as well as by MEK inhibitor U0126. Furthermore, anti-CD95 ZB4 mAb prevented dexamethasone-induced apoptosis in immune complex stimulated monocytes. Similarly, ZB4 inhibited dexamethasone-mediated augmentation of caspase 3 activity. The present findings suggest that Fc triggering by insoluble immune complexes result in the activation of two intracellular pathways crucial for the survival of monocytes: 1. Ras/MEK/ERK pathway responsible for the down-regulation of CD95 expression; 2. NF-kappaB pathway governing the expression of XIAP. Both the pathways are susceptible to inhibition by monocyte treatment with pharmacologic concentrations of dexamethasone. PMID:16164824

  10. CD14{sup +} monocytes promote the immunosuppressive effect of human umbilical cord matrix stem cells

    SciTech Connect

    Wang, Ding; TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin ; Chen, Ke; TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin ; Du, Wei Ting; Han, Zhi-Bo; TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin ; Ren, He; Chi, Ying; TEDA Life and Technology Research Center, Institute of Hematology, Chinese Academy of Medical Sciences, TEDA, Tianjin ; and others

    2010-09-10

    Here, the effect of CD14{sup +} monocytes on human umbilical cord matrix stem cell (hUC-MSC)-mediated immunosuppression was studied in vitro. hUC-MSCs exerted a potent inhibitory effect on the proliferation and interferon-{gamma} (IFN-{gamma}) secretion capacities of CD4{sup +} and CD8{sup +} T cells in response to anti-CD3/CD28 stimulation. Transwell co-culture system revealed that the suppressive effect was primarily mediated by soluble factors. Addition of prostaglandin synthesis inhibitors (indomethacin or NS-398) almost completely abrogated the immunosuppression activity of hUC-MSCs, identifying prostaglandin E{sub 2} (PGE{sub 2}) as an important soluble mediator. CD14{sup +} monocytes were found to be able to enhance significantly the immunosuppressive effect of hUC-MSCs in a dose-dependent fashion. Moreover, the inflammatory cytokine IL-1{beta}, either exogenously added or produced by CD14{sup +} monocytes in culture, could trigger expression of high levels of PGE{sub 2} by hUC-MSCs, whereas inclusion of the IL-1 receptor antagonist (IL-1RA) in the culture down-regulated not only PGE{sub 2} expression, but also reversed the promotional effect of CD14{sup +} monocytes and partially restored CD4{sup +} and CD8{sup +} T cell proliferation and IFN-{gamma} secretion. Our data demonstrate an important role of monocytes in the hUC-MSC-induced immunomodulation, which may have important implications in future efforts to explore the clinical potentials of hUC-MSCs.

  11. Alpha-tocopherol inhibits agonist-induced monocytic cell adhesion to cultured human endothelial cells.

    PubMed Central

    Faruqi, R; de la Motte, C; DiCorleto, P E

    1994-01-01

    Antioxidants have been proposed to be anti-atherosclerotic agents; however, the mechanisms underlying their beneficial effects are poorly understood. We have examined the effect of alpha-tocopherol (alpha-tcp) on one cellular event in atherosclerotic plaque development, monocyte adhesion to stimulated endothelial cells (ECs). Human umbilical vein ECs were pretreated with alpha-tcp before stimulation with known agonists of monocyte adhesion: IL-1 (10 ng/ml), LPS (10 ng/ml), thrombin (30 U/ml), or PMA (10 nM). Agonist-induced monocytic cell adhesion, but not basal adhesion, was inhibited in a time- and concentration-dependent manner by alpha-tcp. The IC50 of alpha-tcp on an IL-1-induced response was 45 microM. The inhibition correlated with a decrease in steady state levels of E-selectin mRNA and cell surface expression of E-selectin which is consistent with the ability of a monoclonal antibody to E-selectin to inhibit monocytic cell adhesion in this system. Probucol (50 microM) and N-acetylcysteine (20 mM) also inhibited agonist-induced monocytic cell adhesion; whereas, several other antioxidants had no significant effect. Protein kinase C (PKC) does not appear to play a role in the alpha-tcp effect since no suppression of phosphorylation of PKC substrates was observed. Activation of the transcription factor NF-kappa B is reported to be necessary but not sufficient for E-selectin expression in EC. Electrophoretic mobility shift assays failed to show an alpha-tcp-induced decrease in activation of this transcription factor after cytokine stimulation. It has been hypothesized that alpha-tcp acts as an anti-atherosclerotic molecule by inhibiting generation of oxidized LDL--a putative triggering molecule in the atherosclerotic process. Our results point to a novel alternative mechanism of action of alpha-tcp. Images PMID:7518838

  12. Matrix metalloproteinase-12 gene regulation by a PPAR alpha agonist in human monocyte-derived macrophages

    SciTech Connect

    Souissi, Imen Jguirim; Billiet, Ludivine; Cuaz-Perolin, Clarisse; Rouis, Mustapha

    2008-11-01

    MMP-12, a macrophage-specific matrix metalloproteinase with large substrate specificity, has been reported to be highly expressed in mice, rabbits and human atherosclerotic lesions. Increased MMP-12 from inflammatory macrophages is associated with several degenerative diseases such as atherosclerosis. In this manuscript, we show that IL-1{beta}, a proinflammatory cytokine found in atherosclerotic plaques, increases both mRNA and protein levels of MMP-12 in human monocyte-derived macrophages (HMDM). Since peroxisome proliferator-activated receptors (PPARs), such as PPAR{alpha} and PPAR{gamma}, are expressed in macrophages and because PPAR activation exerts an anti-inflammatory effect on vascular cells, we have investigated the effect of PPAR{alpha} and {gamma} isoforms on MMP-12 regulation in HMDM. Our results show that MMP-12 expression (mRNA and protein) is down regulated in IL-1{beta}-treated macrophages only in the presence of a specific PPAR{alpha} agonist, GW647, in a dose-dependent manner. In contrast, this inhibitory effect was abolished in IL-1{beta}-stimulated peritoneal macrophages isolated from PPAR{alpha}{sup -/-} mice and treated with the PPAR{alpha} agonist, GW647. Moreover, reporter gene transfection experiments using different MMP-12 promoter constructs showed a reduction of the promoter activities by {approx} 50% in IL-1{beta}-stimulated PPAR{alpha}-pre-treated cells. However, MMP-12 promoter analysis did not reveal the presence of a PPRE response element. The IL-1{beta} effect is known to be mediated through the AP-1 binding site. Mutation of the AP-1 site, located at - 81 in the MMP-12 promoter region relative to the transcription start site, followed by transfection analysis, gel shift and ChIP experiments revealed that the inhibitory effect was the consequence of the protein-protein interaction between GW 647-activated PPAR{alpha} and c-Fos or c-Jun transcription factors, leading to inhibition of their binding to the AP-1 motif. These studies

  13. Induction of IL-12 from human monocytes after stimulation with Androctonus crassicauda scorpion venom.

    PubMed

    Saadi, Samahir; Assarehzadegan, Mohammad-Ali; Pipelzadeh, Mohammad Hassan; Hadaddezfuli, Reza

    2015-11-01

    The objective of this study was to evaluate the capacity of venom from Androctonus crassicauda to induce expression/production of interleukin (IL)-12 by isolated human monocytes. For this purpose, isolated human monocytes were exposed to different concentrations of the venom (0.16-20 μg/ml) for varying periods (6, 12, and 24 h). Apart from measures of venom cytotoxicity (i.e., lactase dehydrogenase activity [LDH] release), measures of IL-12 p40 mRNA (by Real-time PCR) of IL-12 release (by ELISA) were performed. The results showed that the venom produced significant concentration- and duration of incubation-dependent cytotoxicity. Expression of IL-12 p40 mRNA was significantly increased at all exposure timepoints relative to that in unexposed cells, but was maximal after 6 h of exposure. At that timepoint, the effect from a dose of 2.5 μg venom/ml provided the maximal increase among all doses tested. At the level of the protein itself, IL-12 production remained almost consistently elevated (vs. unexposed control values) across all exposure timepoints, with the greatest formation again occurring after 6 h of incubation at a dose of 2.5 μg venom/ml. The findings from this study demonstrated that venom from the A. crassicauda scorpion contained active constituents that could induce a sustained activation of human monocytes that was manifested, in part, as promotion of the expression/production of IL-12. PMID:26415903

  14. Down-regulated expression of monocyte/macrophage major histocompatibility complex receptors in human and mouse monocytes by expression of their ligands

    PubMed Central

    Yamana, H; Tashiro-Yamaji, J; Hayashi, M; Maeda, S; Shimizu, T; Tanigawa, N; Uchiyama, K; Kubota, T; Yoshida, R

    2014-01-01

    Mouse monocyte/macrophage major histocompatibility complex (MHC) receptor 1 (MMR1; or MMR2) specific for H-2Dd (or H-2Kd) molecules is expressed on monocytes from non-H-2Dd (or non-H-2Kd), but not those from H-2Dd (or H-2Kd), inbred mice. The MMR1 and/or MMR2 is essential for the rejection of H-2Dd- and/or H-2Kd-transgenic mouse skin onto C57BL/6 (H-2DbKb) mice. Recently, we found that human leucocyte antigen (HLA)-B44 was the sole ligand of human MMR1 using microbeads that had been conjugated with 80 types of HLA class I molecules covering 94·2% (or 99·4%) and 92·4% (or 96·2%) of HLA-A and B molecules of Native Americans (or Japanese), respectively. In the present study, we also explored the ligand specificity of human MMR2 using microbeads. Microbeads coated with HLA-A32, HLA-B13 or HLA-B62 antigens bound specifically to human embryonic kidney (HEK)293T or EL-4 cells expressing human MMR2 and to the solubilized MMR2-green fluorescent protein (GFP) fusion protein; and MMR2+ monocytes from a volunteer bound HLA-B62 molecules with a Kd of 8·7 × 10−9 M, implying a three times down-regulation of MMR2 expression by the ligand expression. H-2Kd (or H-2Dd) transgene into C57BL/6 mice down-regulated not only MMR2 (or MMR1) but also MMR1 (or MMR2) expression, leading to further down-regulation of MMR expression. In fact, monocytes from two (i.e. MMR1+/MMR2+ and MMR1–/MMR2–) volunteers bound seven to nine types of microbeads among 80, indicating ≤ 10 types of MMR expression on monocytes. The physiological role of constitutive MMRs on monocytes possibly towards allogeneic (e.g. fetal) cells in the blood appears to be distinct from that of inducible MMRs on macrophages toward allografts in tissue. PMID:24842626

  15. Human monocytes undergo functional re-programming during differentiation to dendritic cell mediated by human extravillous trophoblasts

    PubMed Central

    Zhao, Lei; Shao, Qianqian; Zhang, Yun; Zhang, Lin; He, Ying; Wang, Lijie; Kong, Beihua; Qu, Xun

    2016-01-01

    Maternal immune adaptation is required for a successful pregnancy to avoid rejection of the fetal–placental unit. Dendritic cells within the decidual microenvironment lock in a tolerogenic profile. However, how these tolerogenic DCs are induced and the underlying mechanisms are largely unknown. In this study, we show that human extravillous trophoblasts redirect the monocyte-to-DC transition and induce regulatory dendritic cells. DCs differentiated from blood monocytes in the presence of human extravillous trophoblast cell line HTR-8/SVneo displayed a DC-SIGN+CD14+CD1a− phenotype, similar with decidual DCs. HTR8-conditioned DCs were unable to develop a fully mature phenotype in response to LPS, and altered the cytokine secretory profile significantly. Functionally, conditioned DCs poorly induced the proliferation and activation of allogeneic T cells, whereas promoted CD4+CD25+Foxp3+ Treg cells generation. Furthermore, the supernatant from DC and HTR-8/SVneo coculture system contained significant high amount of M-CSF and MCP-1. Using neutralizing antibodies, we discussed the role of M-CSF and MCP-1 during monocyte-to-DCs differentiation mediated by extravillous trophoblasts. Our data indicate that human extravillous trophoblasts play an important role in modulating the monocyte-to-DC differentiation through M-CSF and MCP-1, which facilitate the establishment of a tolerogenic microenvironment at the maternal–fetal interface. PMID:26857012

  16. Human monocytes undergo functional re-programming during differentiation to dendritic cell mediated by human extravillous trophoblasts.

    PubMed

    Zhao, Lei; Shao, Qianqian; Zhang, Yun; Zhang, Lin; He, Ying; Wang, Lijie; Kong, Beihua; Qu, Xun

    2016-01-01

    Maternal immune adaptation is required for a successful pregnancy to avoid rejection of the fetal-placental unit. Dendritic cells within the decidual microenvironment lock in a tolerogenic profile. However, how these tolerogenic DCs are induced and the underlying mechanisms are largely unknown. In this study, we show that human extravillous trophoblasts redirect the monocyte-to-DC transition and induce regulatory dendritic cells. DCs differentiated from blood monocytes in the presence of human extravillous trophoblast cell line HTR-8/SVneo displayed a DC-SIGN(+)CD14(+)CD1a(-) phenotype, similar with decidual DCs. HTR8-conditioned DCs were unable to develop a fully mature phenotype in response to LPS, and altered the cytokine secretory profile significantly. Functionally, conditioned DCs poorly induced the proliferation and activation of allogeneic T cells, whereas promoted CD4(+)CD25(+)Foxp3(+) Treg cells generation. Furthermore, the supernatant from DC and HTR-8/SVneo coculture system contained significant high amount of M-CSF and MCP-1. Using neutralizing antibodies, we discussed the role of M-CSF and MCP-1 during monocyte-to-DCs differentiation mediated by extravillous trophoblasts. Our data indicate that human extravillous trophoblasts play an important role in modulating the monocyte-to-DC differentiation through M-CSF and MCP-1, which facilitate the establishment of a tolerogenic microenvironment at the maternal-fetal interface. PMID:26857012

  17. CD16⁺ monocytes with smooth muscle cell characteristics are reduced in human renal chronic transplant dysfunction.

    PubMed

    Boersema, M; van den Born, J C; van Ark, J; Harms, G; Seelen, M A; van Dijk, M C R F; van Goor, H; Navis, G J; Popa, E R; Hillebrands, J L

    2015-05-01

    In chronic transplant dysfunction (CTD), persistent (allo)immune-mediated inflammation eventually leads to tissue remodeling including neointima formation in intragraft arteries. We previously showed that recipient-derived neointimal α-SMA(+) smooth muscle-like cells are present in human renal allografts with CTD. Human PBMC contain myeloid cells capable of differentiating into α-SMA(+) cells in vitro; the phenotype of the ancestral subset is as yet unknown. This study aimed to investigate whether monocyte subsets contain cells with smooth muscle-like cell differentiation capacity and whether CTD in renal transplant recipients is associated with a shift in these monocyte subsets. To accomplish this goal, monocyte subsets from healthy controls were sorted based on CD14 and CD16 expression to investigate gene expression levels of mesenchymal markers α-SMA and SM22α. CD14(+)/CD16(++) monocytes displayed increased α-SMA and SM22α mRNA expression compared with CD14(++)/CD16(-) monocytes, suggesting increased differentiation potential toward smooth muscle-like cells. Flow cytometry revealed that in non-CTD transplant recipients the percentage of CD14(+)/CD16(++) monocytes was reduced, with an even further reduction in patients with CTD. To determine a potential correlation between CD14(+)/CD16(++) monocytes and α-SMA(+) cell outgrowth potential in vitro, PBMC of healthy controls and transplant recipients with and without CTD were cultured under fibrotic culture conditions, and indeed a significant correlation (p=0.0002, r=0.62) was observed. Finally, double staining for α-SMA and CD16 revealed presence of α-SMA(+)CD16(+) cells in kidney explants from CTD patients, albeit at very low numbers. Our data represent evidence that, compared to CD14(++)CD16(-) monocytes, CD14(+)CD16(++) monocytes have an increased expression of smooth muscle cell-associated genes. This monocyte subpopulation is reduced in renal transplant patients with CTD, possibly due to selective

  18. Vasoactive intestinal peptide (VIP) differentially affects inflammatory immune responses in human monocytes infected with viable Salmonella or stimulated with LPS.

    PubMed

    Askar, Basim; Ibrahim, Hiba; Barrow, Paul; Foster, Neil

    2015-09-01

    We compared the effect of VIP on human blood monocytes infected with Salmonella typhimurium 4/74 or stimulated with LPS. VIP (10(-7)M) increased monocyte viability by 24% and 9% when cultured for 24h with 4/74 or Salmonella LPS (100ng/ml), respectively. Significantly increased (P<0.05) numbers of 4/74 were also recovered from monocytes co-cultured with VIP after 6h post-infection (pi) and this remained high after 24h pi. Both 4/74 and LPS increased (P<0.05) the concentration of TNF-α, IL-1β and IL-6 measured in monocyte supernatants. However, LPS induced this effect more rapidly while, with the exception of IL-6, 4/74 induced higher concentrations (P<0.05). VIP significantly decreased (P<0.05) TNF-α and IL-1β production by 4/74-infected monocytes after 6 pi, but only after 24h in LPS-cultured monocytes. This trend was reversed for IL-6 production. However, TNF-α and IL-1β production by 4/74-infected monocytes, cultured with VIP, still remained higher (P<0.05) than concentrations measured in supernatants cultured only with LPS. VIP also increased (P<0.05) production of anti-inflammatory IL-10 in both 4/74 and LPS cultures after 24h. We also show a differential effect of VIP on the expression of TNFα and IL-6 receptors, since VIP was only able to decreased expression in LPS-stimulated monocytes but not in 4/74-infected monocytes. In conclusion, we show a differential effect of VIP on human monocytes infected with virulent Salmonella or stimulated with LPS. Our study suggests that the use of VIP in bacteraemia and/or sepsis may be limited to an adjunctive therapy to antibiotic treatment. PMID:26206287

  19. Erythropoietin receptor is expressed on human peripheral blood T and B lymphocytes and monocytes and is modulated by recombinant human erythropoietin treatment.

    PubMed

    Lisowska, Katarzyna A; Debska-Slizień, Alicja; Bryl, Ewa; Rutkowski, Bolesław; Witkowski, Jacek M

    2010-08-01

    Erythropoietin receptor (EPO-R) appears on the cell surface in the early stages of erythropoiesis. It has also been found on endothelial cells and polymorphonuclear leukocytes, suggesting erythropoietin (EPO) role beyond erythropoiesis itself. Earlier reports have shown that treatment with recombinant human erythropoietin (rhEPO) in chronic renal failure (CRF) patients improves interleukin-2 production and restores the T lymphocyte function. We decided to investigate possible expression of EPO-R on circulating peripheral blood lymphocytes and monocytes of CRF patients in order to assess the possibility of rhEPO direct action on these cells. Flow cytometry was used for detection and quantification of EPO-R, and reverse transcription polymerase chain reaction for detection of the EPO receptor mRNA. Our results show for the first time the existence of EPO-R on cell surface of human T and B lymphocytes and monocytes as well as at the transcriptional activity of the EPO-R gene in these cells, both in healthy and CRF individuals. We have also found significant differences between the numbers of EPO-R molecules on T and B lymphocytes of CRF patients not treated and treated with rhEPO and healthy control. Discovery of EPO-R expression on human lymphocytes suggests that EPO is probably able to directly modulate some signaling pathways important for these cells. PMID:20528849

  20. Induction and antimicrobial activity of platelet basic protein derivatives in human monocytes.

    PubMed

    Schaffner, Andreas; King, Charles C; Schaer, Dominik; Guiney, Donald G

    2004-11-01

    The antimicrobial activity of a number of chemokines has recently come into focus of research about innate immunity. We have previously shown that platelet basic protein (PBP), which gives rise to several antimicrobial peptides of platelets, is also expressed in human monocytes. In the present studies, we show that exposure of human monocytes to bacteria or microbial components (lipopolysaccharide and zymosan) induces a several-fold greater expression of derivates of PBP. Also, activation of proteinase-activated receptors (PARs) by thrombin or the synthetic peptide ligand SFLLRN of PAR-1 significantly increased PBP expression, presumably on the transcriptional level, as evidenced by higher mRNA levels. Derivates of PBP appeared to reach phago-lysosomes, as higher concentration was found in latex phagosomes isolated by a flotation method. By the gel-overlay technique, two bactericidal derivatives of PBP could be visualized, which were immunoreactive with anti-PBP antibody in Western blots. By matrix-assisted laser desorption/ionization time of flight and surface-enhanced laser desorption and ionization techniques, it was confirmed that the bands corresponded to PBP derivates. After immunofixation with a monoclonal antibody to PBP, the major peptide in zymosan-stimulated monocytes was identified to correspond by molecular weight to connective tissue-activating peptide III, which has been reported to be a major antimicrobial PBP derivate also in platelets. Our observations indicate that PBP and its derivates are constituents of the antimicrobial arsenal of human monocytes. Their increased expression after exposure to microorganisms allows a rapid host response to pathogens. PMID:15316029

  1. Effects of increasing docosahexaenoic acid intake in human healthy volunteers on lymphocyte activation and monocyte apoptosis

    PubMed Central

    Mebarek, Saïda; Ermak, Natalia; Benzaria, Amal; Vicca, Stéphanie; Dubois, Madeleine; Némoz, Georges; Laville, Martine; Lacour, Bernard; Véricel, Evelyne; Lagarde, Michel; Prigent, Annie-France

    2009-01-01

    Dietary intake of long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) has been reported to decrease several markers of lymphocyte activation and modulate monocyte susceptibility to apoptosis. However most human studies examined the combined effect of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) using relatively high daily amounts of n-3 PUFA. The present study investigated the effects of increasing doses of DHA added to the regular diet of human healthy volunteers on lymphocyte response to tetradecanoylphorbol acetate (TPA) plus ionomycin activation, and on monocyte apoptosis induced by oxidized LDL (oxLDL). Eight subjects were supplemented with increasing daily doses of DHA (200, 400, 800 and 1600mg) in a triacylglycerol form containing DHA as the only PUFA, for two weeks each dose. DHA intake dose-dependently increased the proportion of DHA in mononuclear cell phospholipids, the augmentation being significant after 400mg DHA/day. The TPA plus ionomycin-stimulated IL-2 mRNA level started to increase after ingestion of 400mg DHA/day, with a maximum after 800mg intake, and was positively correlated (P<0.003) with DHA enrichment in cell phospholipids. The treatment of monocytes by oxLDL before DHA supplementation drastically reduced mitochondrial membrane potential as compared with native LDL treatment. OxLDL apoptotic effect was significantly attenuated after 400mg DHA/day and the protective effect was maintained throughout the experiment, although to a lesser extent at higher doses. The present results show that supplementation of the human diet with low DHA dosages improves lymphocyte activability. It also increases monocyte resistance to oxLDL-induced apoptosis, which may be beneficial in the prevention of atherosclerosis. PMID:18710607

  2. Borrelia garinii Induces CXCL13 Production in Human Monocytes through Toll-Like Receptor 2▿

    PubMed Central

    Rupprecht, Tobias A.; Kirschning, Carsten J.; Popp, Bernadette; Kastenbauer, Stefan; Fingerle, Volker; Pfister, Hans-Walter; Koedel, Uwe

    2007-01-01

    Recent studies have suggested an important role for the B-cell-attracting chemokine CXCL13 in the B-cell-dominated cerebrospinal fluid (CSF) infiltrate in patients with neuroborreliosis (NB). High levels of CXCL13 were present in the CSF of NB patients. It has not been clear, however, whether high CSF CXCL13 titers are specific for NB or are a characteristic of other spirochetal diseases as well. Furthermore, the mechanisms leading to the observed CXCL13 expression have not been identified yet. Here we describe similarly elevated CSF CXCL13 levels in patients with neurosyphilis, while pneumococcal meningitis patient CSF do not have high CXCL13 levels. In parallel, challenge of human monocytes in vitro with two of the spirochetal causative organisms, Borrelia garinii (the Borrelia species most frequently found in NB patients) and Treponema pallidum, but not challenge with pneumococci, induced CXCL13 release. This finding implies that a common spirochetal motif is a CXCL13 inducer. Accordingly, we found that the lipid moiety N-palmitoyl-S-(bis[palmitoyloxy]propyl)cystein (Pam3C) (three palmitoyl residues bound to N-terminal cysteine) of the spirochetal lipoproteins is critical for the CXCL13 induction in monocytes. As the Pam3C motif is known to signal via Toll-like receptor 2 (TLR2) and an anti-TLR2 monoclonal antibody blocked CXCL13 production of human monocytes incubated with B. garinii, this suggests that TLR2 is a major mediator of Borrelia-induced secretion of CXCL13 from human monocytes. PMID:17562761

  3. Profiling of histamine H4 receptor agonists in native human monocytes

    PubMed Central

    Gschwandtner, M; Koether, B; Werfel, T; Stark, H; Gutzmer, R

    2013-01-01

    Background and Purpose Since the identification of the histamine H4 receptor, several ligands activating this receptor have been described and more compounds are in development. These ligands are well characterized in pharmacological assays, including radioligand competition binding studies, GTPγS and GTPase assays. In most cases, these experiments are performed in transfected cell lines, expressing unnaturally high levels of target receptors and G-protein signalling components. In this study we investigated the specific properties of H4 receptor ligands in native cells. Experimental Approach Histamine and five different H4 receptor agonists – 4-methylhistamine, UR-PI376, clobenpropit, VUF8430 and ST-1006 – were characterized in freshly isolated human monocytes. The ligands (10 nM–10 μM) were tested as inhibitors of IL-12p70 secretion from human monocytes and the effects of the H2 receptor antagonist ranitidine and the H4 receptor antagonist JNJ7777120 on their action was investigated. Key Results Histamine and all the tested agonists reduced IL-12p70 secretion into monocyte supernatants by 40–70%. The potencies varied with pEC50 values ranging from 5.7 to 6.9, depending on the agonist used. All potencies were lower than those determined in the original investigations of the compounds. Pretreatment of monocytes with H2 or H4 receptor antagonists showed that some H4 receptor ligands also had low activity at the H2 receptor. Conclusions and Implications Our study demonstrates discrepancies between the potencies obtained from assays in transfected cell lines and assays in native human cells, indicating the importance of evaluating H4 receptor ligands in native cells. Linked Articles This article is part of a themed issue on Histamine Pharmacology Update. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2013.170.issue-1 PMID:23638754

  4. A Single-Cell Gene-Expression Profile Reveals Inter-Cellular Heterogeneity within Human Monocyte Subsets

    PubMed Central

    Gren, Susanne T.; Rasmussen, Thomas B.; Janciauskiene, Sabina; Håkansson, Katarina; Gerwien, Jens G.; Grip, Olof

    2015-01-01

    Human monocytes are a heterogeneous cell population classified into three different subsets: Classical CD14++CD16-, intermediate CD14++CD16+, and non-classical CD14+CD16++ monocytes. These subsets are distinguished by their differential expression of CD14 and CD16, and unique gene expression profile. So far, the variation in inter-cellular gene expression within the monocyte subsets is largely unknown. In this study, the cellular variation within each human monocyte subset from a single healthy donor was described by using a novel single-cell PCR gene-expression analysis tool. We investigated 86 different genes mainly encoding cell surface markers, and proteins involved in immune regulation. Within the three human monocyte subsets, our descriptive findings show multimodal expression of key immune response genes, such as CD40, NFⱪB1, RELA, TLR4, TLR8 and TLR9. Furthermore, we discovered one subgroup of cells within the classical monocytes, which showed alterations of 22 genes e.g. IRF8, CD40, CSF1R, NFⱪB1, RELA and TNF. Additionally one subgroup within the intermediate and non-classical monocytes also displayed distinct gene signatures by altered expression of 8 and 6 genes, respectively. Hence the three monocyte subsets can be further subdivided according to activation status and differentiation, independently of the traditional classification based on cell surface markers. Demonstrating the use and the ability to discover cell heterogeneity within defined populations of human monocytes is of great importance, and can be useful in unravelling inter-cellular variation in leukocyte populations, identifying subpopulations involved in disease pathogenesis and help tailor new therapies. PMID:26650546

  5. Creatine kinase expression and creatine phosphate accumulation are developmentally regulated during differentiation of mouse and human monocytes

    PubMed Central

    1984-01-01

    We have studied the expression of creatine kinase (CK) and the accumulation of creatine phosphate during the differentiation of human and mouse peripheral blood monocytes. Mouse monocytes cultured for 24 h do not contain detectable levels of CK and creatine phosphate. However, resident tissue macrophages and inflammatory elicited macrophages obtained from the peritoneal cavities of mice have 70 and 300 mU per mg protein of CK activity and contain 3 and 6 mol of creatine phosphate per mol of ATP, respectively. The major isozyme of CK in these cells has been identified as the brain form. These findings suggest that the differentiation of monocytes into macrophages is associated with the expression of CK and the accumulation of creatine phosphate. We have found a similar pattern in human monocytes. Human blood monocytes, maintained in culture for 24 or 48 h, do not contain detectable levels of CK or creatine phosphate. Monocyte-derived macrophages (monocytes maintained in tissue cultures for 1 to 2 wk) have up to 100 mU per mg protein of CK activity and contain 0.5 mol of creatine phosphate per mol of ATP. Human macrophages express multiple isozymes of CK including the brain (BB) and possibly the mitochondrial forms of this enzyme. Thus, the expression of CK and the accumulation of creatine phosphate in human monocytes is induced by their in vitro cultivation. The induction of CK during in vitro cultivation occurs independently of the concentration of creatine in the medium. However, the size of the creatine phosphate pool varies with respect to extracellular creatine concentration. Creatine phosphate and CK are not detectable in freshly isolated human lymphocytes, polymorphonuclear leukocytes or erythrocytes, but are found in freshly isolated human platelets. PMID:6699543

  6. Dendritic cells treated with resveratrol during differentiation from monocytes gain substantial tolerogenic properties upon activation

    PubMed Central

    Švajger, Urban; Obermajer, Nataša; Jeras, Matjaž

    2010-01-01

    Resveratrol is a polyphenol that acts on multiple molecular targets important for cell differentiation and activation. Dendritic cells (DCs) are a functionally diverse cell type and represent the most potent antigen-presenting cells of the immune system. In this study, we investigated resveratrol-induced effects on DCs during their differentiation and maturation. Our results show that resveratrol induces DC-associated tolerance, particularly when applied during DC differentiation. Costimulatory molecules CD40, CD80 and CD86 were down-regulated, as was the expression of major histocompatibility complex (MHC) class II molecules. Surface expression of inhibitory immunoglobulin-like transcript 3 (ILT3) and ILT4 molecules was induced, while human leucocyte antigen (HLA)-G expression was not affected. Resveratrol-treated DCs lost the ability to produce interleukin (IL)-12p70 after activation, but had an increased ability to produce IL-10. Such DCs were poor stimulators of allogeneic T cells and had lowered ability to induce CD4+ T-cell migration. Furthermore, treated cells were able to generate allogeneic IL-10-secreting T cells, but were not competent in inducing FoxP3 expression These tolerogenic effects are probably associated with the effect of resveratrol on multiple molecular targets through which it interferes with DC differentiation and nuclear factor (NF)-κB translocation. Our data provide new insights into the molecular and functional mechanisms of the tolerogenic effects that resveratrol exerts on DCs. PMID:20002210

  7. In vitro immunotoxicity assessment of culture-derived extracellular vesicles in human monocytes.

    PubMed

    Rosas, Lucia E; Elgamal, Ola A; Mo, Xiaokui; Phelps, Mitch A; Schmittgen, Thomas D; Papenfuss, Tracey L

    2016-09-01

    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

  8. cGAS Senses Human Cytomegalovirus and Induces Type I Interferon Responses in Human Monocyte-Derived Cells.

    PubMed

    Paijo, Jennifer; Döring, Marius; Spanier, Julia; Grabski, Elena; Nooruzzaman, Mohammed; Schmidt, Tobias; Witte, Gregor; Messerle, Martin; Hornung, Veit; Kaever, Volkhard; Kalinke, Ulrich

    2016-04-01

    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

  9. 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

  10. Effects of transforming growth factor-beta on long-term human cord blood monocyte cultures

    SciTech Connect

    Orcel, P.; Bielakoff, J.; De Vernejoul, M.C. )

    1990-02-01

    Transforming growth factor-beta (TGF-beta) modulates growth and differentiation in many cell types and is abundant in bone matrix. We recently showed that human cord blood monocytes cultured in the presence of 1,25(OH)2D3 acquire some features of osteoclast precursors. Since TGF-beta has been shown to influence bone resorption in organ culture, we have studied the effect of TGF-beta (1-1,000 pg/ml) on cord blood monocyte cultures. These cells were cultured on plastic substrate during 3 weeks in the presence of 20% horse serum and 10(-9) M 1,25(OH)2D3. TGF-beta, from a concentration of 10 pg/ml in the culture medium, decreased in a dose dependent manner the formation of multinucleated cells. At a concentration of TGF-beta of 1 ng/ml, the multinucleated cells were reduced to 2.1% +/- 0.3%, compared to 19.3% +/- 1.5% in control cultures. TGF-beta inhibited in a dose-dependent manner the proliferation of cord blood monocytes as assessed by 3H-thymidine incorporation at 7 and 14 days of culture. The fusion index was also decreased by 3 weeks of treatment with TGF-beta. Indomethacin did not reverse the inhibitory effects of TGF-beta. The expression of the osteoclastic phenotype was assessed using two different antibodies: 23C6, a monoclonal antibody directed against the vitronectin receptor, which is highly expressed by osteoclasts but not by adult monocytes, and an antibody to HLA-DR, which is not present on osteoclast. TGF-beta decreased the expression of HLA-DR and increased in a dose-dependent manner the proportion of 23C6-labeled cells; these results suggest that TGF-beta could modulate a differentiation effect to the osteoclastic phenotype. However, when cord blood monocytes were cultured on devitalized rat calvariae prelabeled with 45Ca, TGF-beta did not induce any 45Ca release from bone cultured with monocytes.

  11. Ganoderma lucidum polysaccharides can induce human monocytic leukemia cells into dendritic cells with immuno-stimulatory function

    PubMed Central

    Chan, Wing Keung; Cheung, Christopher Ching Hang; Law, Helen Ka Wai; Lau, Yu Lung; Chan, Godfrey Chi Fung

    2008-01-01

    Background Previous studies demonstrated Ganoderma lucidum polysaccharides (GL-PS), a form of bioactive β-glucan can stimulate the maturation of monocyte-derived dendritic cells (DC). The question of how leukemic cells especially in monocytic lineage respond to GL-PS stimuli remains unclear. Results In this study, we used in vitro culture model with leukemic monocytic cell-lines THP-1 and U937 as monocytic effectors cells for proliferation responses and DCs induction. We treated the THP-1 and U937 cells with purified GL-PS (100 μg/mL) or GL-PS with GM-CSF/IL-4. GL-PS alone induced proliferative response on both THP-1 and U937 cells but only THP-1 transformed into typical DC morphology when stimulated with GL-PS plus GM-CSF/IL-4. The transformed THP-1 DCs had significant increase expression of HLA-DR, CD40, CD80 and CD86 though not as high as the extent of normal monocyte-derived DCs. They had similar antigen-uptake ability as the normal monocyte-derived DCs positive control. However, their potency in inducing allogeneic T cell proliferation was also less than that of normal monocyte-derived DCs. Conclusion Our findings suggested that GL-PS could induce selected monocytic leukemic cell differentiation into DCs with immuno-stimulatory function. The possible clinical impact of using this commonly used medicinal mushroom in patients with monocytic leukemia (AML-M4 and M5) deserved further investigation. PMID:18644156

  12. Modulation of the Cytokine Response in Human Monocytes by Mycobacterium leprae Phenolic Glycolipid-1

    PubMed Central

    Manca, Claudia; Peixoto, Blas; Malaga, Wladimir; Guilhot, Christophe

    2012-01-01

    Leprosy is a chronic but treatable infectious disease caused by the intracellular pathogen Mycobacterium leprae. M. leprae cell wall is characterized by a unique phenolic glycolipid-1 (PGL-1) reported to have several immune functions. We have examined the role of PGL-1 in the modulation of monocyte cytokine/chemokine production in naive human monocytes. PGL-1 in its purified form or expressed in a recombinant Mycobacterium bovis Bacillus Colmette-Guérin (BCG) background (rBCG-PGL-1) was tested. We found that PGL-1 selectively modulated the induction of specific monocyte cytokines and chemokines and, when used as prestimulus, exerted priming and/or inhibitory effects on the induction of selected cytokines/chemokines in response to a second stimulus. Taken together, the results of this study support a modulatory role for PGL-1 in the innate immune response to M. leprae. Thus, PGL-1 may play an important role in the development of the anergic clinical forms of disease and in tissue damage seen in lepromatous patients and during the reactional states of leprosy. PMID:21981546

  13. Thrombin selectively induces transcription of genes in human monocytes involved in inflammation and wound healing.

    PubMed

    López, Mercedes L; Bruges, Gustavo; Crespo, Gustavo; Salazar, Victor; Deglesne, Pierre-Antoine; Schneider, Heike; Cabrera-Fuentes, Hector; Schmitz, M Lienhard; Preissner, Klaus T

    2014-11-01

    Thrombin is essential for blood coagulation but functions also as a mediator of cellular signalling. Gene expression microarray experiments in human monocytes revealed thrombin-induced upregulation of a limited subset of genes, which are almost exclusively involved in inflammation and wound healing. Among these, the expression of F3 gene encoding for tissue factor (TF) was enhanced indicating that this physiological initiator of coagulation cascade may create a feed-forward loop to enhance blood coagulation. Activation of protease-activated receptor type 1 (PAR1) was shown to play a main role in promoting TF expression. Moreover, thrombin induced phosphorylation of ERK1/2, an event that is required for expression of thrombin-regulated genes. Thrombin also increased the expression of TF at the protein level in monocytes as evidenced by Western blot and immunostaining. Furthermore, FXa generation induced by thrombin-stimulated monocytes was abolished by a TF blocking antibody and therefore it is entirely attributable to the expression of tissue factor. This cellular activity of thrombin provides a new molecular link between coagulation, inflammation and wound healing. PMID:25057055

  14. Silver nanoparticles induce pro-inflammatory gene expression and inflammasome activation in human monocytes.

    PubMed

    Murphy, A; Casey, A; Byrne, G; Chambers, G; Howe, O

    2016-10-01

    A complete cytotoxic profile of exposure to silver (AgNP) nanoparticles investigating their biological effects on the innate immune response of circulating white blood cells is required to form a complete understanding of the risk posed. This was explored by measuring AgNP-stimulated gene expression of the pro-inflammatory cytokines interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) in THP-1 monocytes. A further study, on human monocytes extracted from a cohort of blood samples, was carried out to compare with the AgNP immune response in THP-1 cells along with the detection of pro-IL-1β which is a key mediator of the inflammasome complex. The aims of the study were to clearly demonstrate that AgNP can significantly up-regulate pro-inflammatory cytokine gene expression of IL-1, IL-6 and TNF-α in both THP-1 cells and primary blood monocytes thus indicating a rapid response to AgNP in circulation. Furthermore, a role for the inflammasome in AgNP response was indicated by pro-IL-1β cleavage and release. These results highlight the potential inflammatory effects of AgNP exposure and the responses evoked should be considered with respect to the potential harm that exposure may cause. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26968431

  15. Interleukin-18 Increases TLR4 and Mannose Receptor Expression and Modulates Cytokine Production in Human Monocytes

    PubMed Central

    Dias-Melicio, Luciane Alarcão; Fernandes, Reginaldo Keller; Rodrigues, Daniela Ramos; Golim, Marjorie Assis; Soares, Angela Maria Victoriano Campos

    2015-01-01

    Interleukin-18 is a proinflammatory cytokine belonging to the interleukin-1 family of cytokines. This cytokine exerts many unique biological and immunological effects. To explore the role of IL-18 in inflammatory innate immune responses, we investigated its impact on expression of two toll-like receptors (TLR2 and TLR4) and mannose receptor (MR) by human peripheral blood monocytes and its effect on TNF-α, IL-12, IL-15, and IL-10 production. Monocytes from healthy donors were stimulated or not with IL-18 for 18 h, and then the TLR2, TLR4, and MR expression and intracellular TNF-α, IL-12, and IL-10 production were assessed by flow cytometry and the levels of TNF-α, IL-12, IL-15, and IL-10 in culture supernatants were measured by ELISA. IL-18 treatment was able to increase TLR4 and MR expression by monocytes. The production of TNF-α and IL-10 was also increased by cytokine treatment. However, IL-18 was unable to induce neither IL-12 nor IL-15 production by these cells. Taken together, these results show an important role of IL-18 on the early phase of inflammatory response by promoting the expression of some pattern recognition receptors (PRRs) that are important during the microbe recognition phase and by inducing some important cytokines such as TNF-α and IL-10. PMID:25873755

  16. Effects of urban particulate matter with high glucose on human monocytes U937.

    PubMed

    Zhang, Yue; Mo, Yiqun; Gu, Aihua; Wan, Rong; Zhang, Qunwei; Tollerud, David J

    2016-04-01

    Epidemiological studies and animal experiments have shown that individuals with preexisting diseases, such as diabetes mellitus (DM), are more susceptible to particulate matter (PM)-related cardiovascular diseases. However, the underlying mechanisms are still unclear. We hypothesized that PM and high glucose combined would cause enhanced effects on activation of monocytes and p38 mitogen-activated protein kinase (MAPK) by inducing oxidative stress, which would further activate matrix metalloproteinases (MMPs). Human monocytes U937 were used to test the effects of urban particulate matter (U-PM) and high glucose. The results showed that exposure of monocytes to non-toxic doses of U-PM alone caused generation of reactive oxygen species (ROS), increased phosphorylation of p38, and activation of monocytes which was reflected by up-regulation of MMP-2, MMP-9 and proinflammatory cytokines IL-1β and IL-8 expression and increased activity of pro-MMP-2 and pro-MMP-9. These effects were enhanced significantly when cells were exposed to U-PM in a high-glucose environment. Our results also showed that pre-treatment of cells with ROS scavengers or inhibitors abolished U-PM and high glucose-induced increased phosphorylation of p38. Up-regulation of pro-MMP-2 and pro-MMP-9 activity by U-PM in the setting of high glucose level was dramatically attenuated by treatment of cells with the p38-specific inhibitor, SB203580. These results suggest that activation of MMPs by U-PM with high glucose is partly through p38 phosphorylation that is induced by oxidative stress. Our findings may have important implications in understanding the potential health effects of PM on susceptible populations such as those with DM. PMID:26179980

  17. Circulating Blood Monocyte Subclasses and Lipid-Laden Adipose Tissue Macrophages in Human Obesity

    PubMed Central

    Pecht, Tal; Haim, Yulia; Bashan, Nava; Shapiro, Hagit; Harman-Boehm, Ilana; Kirshtein, Boris; Clément, Karine; Shai, Iris; Rudich, Assaf

    2016-01-01

    Background Visceral adipose tissue foam cells are increased in human obesity, and were implicated in adipose dysfunction and increased cardio-metabolic risk. In the circulation, non-classical monocytes (NCM) are elevated in obesity and associate with atherosclerosis and type 2 diabetes. We hypothesized that circulating NCM correlate and/or are functionally linked to visceral adipose tissue foam cells in obesity, potentially providing an approach to estimate visceral adipose tissue status in the non-surgical obese patient. Methods We preformed ex-vivo functional studies utilizing sorted monocyte subclasses from healthy donors. Moreover, we assessed circulating blood monocyte subclasses and visceral fat adipose tissue macrophage (ATM) lipid content by flow-cytometry in paired blood and omental-fat samples collected from patients (n = 65) undergoing elective abdominal surgery. Results Ex-vivo, NCM and NCM-derived macrophages exhibited lower lipid accumulation capacity compared to classical or intermediate monocytes/-derived macrophages. Moreover, of the three subclasses, NCM exhibited the lowest migration towards adipose tissue conditioned-media. In a cohort of n = 65, increased %NCM associated with higher BMI (r = 0.250,p<0.05) and ATM lipid content (r = 0.303,p<0.05). Among patients with BMI≥25Kg/m2, linear regression models adjusted for age, sex or BMI revealed that NCM independently associate with ATM lipid content, particularly in men. Conclusions Collectively, although circulating blood NCM are unlikely direct functional precursor cells for adipose tissue foam cells, their increased percentage in the circulation may clinically reflect higher lipid content in visceral ATMs. PMID:27442250

  18. Tetrandrine, a plant alkaloid, inhibits the production of tumour necrosis factor-alpha (cachectin) hy human monocytes.

    PubMed Central

    Ferrante, A; Seow, W K; Rowan-Kelly, B; Thong, Y H

    1990-01-01

    Human mononuclear leucocytes (MNL) or the adherent fraction (monocytes) produced tumour necrosis factor-alpha (TNF-alpha) (by ELISA) in culture when stimulated with killed Staphylococcus aureus. The bisbenzylisoquinoline alkaloid, tetrandrine inhibited the capacity of MNL and monocytes to produce TNF-alpha at a concentration range of 0.1 to 5 micrograms/ml. Tetrandrine may be potentially useful in the treatment of inflammatory diseases in which TNF-alpha plays a major role. PMID:2357850

  19. Receptor-mediated uptake of remnant lipoproteins by cholesterol-loaded human monocyte-macrophages

    SciTech Connect

    Van Lenten, B.J.; Fogelman, A.M.; Jackson, R.L.; Shapiro, S.; Haberland, M.E.; Edwards, P.A.

    1985-07-25

    Normal human monocyte-macrophages were cholesterol-loaded, and the rates of uptake and degradation of several lipoproteins were measured and compared to rates in control cells. Receptor activities for SVI-rabbit beta-very low density lipoproteins (beta-VLDL), SVI-human low density lipoprotein, and SVI-human chylomicrons were down-regulated in cholesterol-loaded cells; however, the rate of uptake and degradation of SVI-human chylomicron remnants was unchanged from control cells. Cholesterol-loaded alveolar macrophages from a Watanabe heritable hyperlipidemic rabbit, which lack low density lipoprotein receptors, showed receptor down-regulation for SVI-beta-VLDL but not for SVI-human chylomicron remnants. In addition to chylomicron remnants, apo-E-phospholipid complexes competed for SVI-chylomicron remnant uptake, but apo-A-I-phospholipid complexes did not. Chylomicron remnants and beta-VLDL were equally effective in competing for SVI-beta-VLDL and SVI-chylomicron remnant uptake in cholesterol-loaded macrophages. The authors conclude: 1) specific lipoprotein receptor activity persists in cholesterol-loaded cells; 2) this receptor activity recognizes lipo-proteins (at least in part) by their apo-E content; and 3) cholesteryl ester accumulation can occur in monocyte-macrophages incubated with chylomicron remnants.

  20. MicroRNA Cargo of Extracellular Vesicles from Alcohol-exposed Monocytes Signals Naive Monocytes to Differentiate into M2 Macrophages.

    PubMed

    Saha, Banishree; Momen-Heravi, Fatemeh; Kodys, Karen; Szabo, Gyongyi

    2016-01-01

    Membrane-coated extracellular vesicles (EVs) released by cells can serve as vehicles for delivery of biological materials and signals. Recently, we demonstrated that alcohol-treated hepatocytes cross-talk with immune cells via exosomes containing microRNA (miRNAs). Here, we hypothesized that alcohol-exposed monocytes can communicate with naive monocytes via EVs. We observed increased numbers of EVs, mostly exosomes, secreted by primary human monocytes and THP-1 monocytic cells in the presence of alcohol in a concentration- and time-dependent manner. EVs derived from alcohol-treated monocytes stimulated naive monocytes to polarize into M2 macrophages as indicated by increased surface expression of CD68 (macrophage marker), M2 markers (CD206 (mannose receptor) and CD163 (scavenger receptor)), secretion of IL-10, and TGFβ and increased phagocytic activity. miRNA profiling of the EVs derived from alcohol-treated THP-1 monocytes revealed high expression of the M2-polarizing miRNA, miR-27a. Treatment of naive monocytes with control EVs overexpressing miR-27a reproduced the effect of EVs from alcohol-treated monocytes on naive monocytes and induced M2 polarization, suggesting that the effect of alcohol EVs was mediated by miR-27a. We found that miR-27a modulated the process of phagocytosis by targeting CD206 expression on monocytes. Importantly, analysis of circulating EVs from plasma of alcoholic hepatitis patients revealed increased numbers of EVs that contained high levels of miR-27a as compared with healthy controls. Our results demonstrate the following: first, alcohol increases EV production in monocytes; second, alcohol-exposed monocytes communicate with naive monocytes via EVs; and third, miR-27a cargo in monocyte-derived EVs can program naive monocytes to polarize into M2 macrophages. PMID:26527689

  1. Adjuvant-induced Human Monocyte Secretome Profiles Reveal Adjuvant- and Age-specific Protein Signatures.

    PubMed

    Oh, Djin-Ye; Dowling, David J; Ahmed, Saima; Choi, Hyungwon; Brightman, Spencer; Bergelson, Ilana; Berger, Sebastian T; Sauld, John F; Pettengill, Matthew; Kho, Alvin T; Pollack, Henry J; Steen, Hanno; Levy, Ofer

    2016-06-01

    Adjuvants boost vaccine responses, enhancing protective immunity against infections that are most common among the very young. Many adjuvants activate innate immunity, some via Toll-Like Receptors (TLRs), whose activities varies with age. Accordingly, characterization of age-specific adjuvant-induced immune responses may inform rational adjuvant design targeting vulnerable populations. In this study, we employed proteomics to characterize the adjuvant-induced changes of secretomes from human newborn and adult monocytes in response to Alum, the most commonly used adjuvant in licensed vaccines; Monophosphoryl Lipid A (MPLA), a TLR4-activating adjuvant component of a licensed Human Papilloma Virus vaccine; and R848 an imidazoquinoline TLR7/8 agonist that is a candidate adjuvant for early life vaccines. Monocytes were incubated in vitro for 24 h with vehicle, Alum, MPLA, or R848 and supernatants collected for proteomic analysis employing liquid chromatography-mass spectrometry (LC-MS) (data available via ProteomeXchange, ID PXD003534). 1894 non-redundant proteins were identified, of which ∼30 - 40% were common to all treatment conditions and ∼5% were treatment-specific. Adjuvant-stimulated secretome profiles, as identified by cluster analyses of over-represented proteins, varied with age and adjuvant type. Adjuvants, especially Alum, activated multiple innate immune pathways as assessed by functional enrichment analyses. Release of lactoferrin, pentraxin 3, and matrix metalloproteinase-9 was confirmed in newborn and adult whole blood and blood monocytes stimulated with adjuvants alone or adjuvanted licensed vaccines with distinct clinical reactogenicity profiles. MPLA-induced adult monocyte secretome profiles correlated in silico with transcriptome profiles induced in adults immunized with the MPLA-adjuvanted RTS,S malaria vaccine (Mosquirix™). Overall, adjuvants such as Alum, MPLA and R848 give rise to distinct and age-specific monocyte secretome profiles

  2. Pyoderma Gangrenosum with Ulcerative Colitis Successfully Treated by the Combination of Granulocyte and Monocyte Adsorption Apheresis and Corticosteroids.

    PubMed

    Ohno, Masashi; Koyama, Shigeki; Ohara, Mariko; Shimamoto, Kazumi; Kobayashi, Yu; Nakamura, Fumiyasu; Mitsuru, Kazuki; Andoh, Akira

    2016-01-01

    A 36-year-old woman was admitted to our hospital due to swelling and redness of the left lateral malleolus and dorsum of the left foot with severe pain, with a flare-up of ulcerative colitis (UC). A pathologic examination by skin biopsy led to a diagnosis of pyoderma gangrenosum (PG). She was treated with the intravenous administration of prednisolone (60 mg/day), and granulocyte and monocyte adsorption apheresis (GMA) was performed twice-a-week for 5 weeks. This treatment dramatically improved both the skin and colonic mucosal lesions. These results suggest that a combination of GMA and corticosteroids might be recommendable to induce the remission of serious PG complicated with UC. PMID:26726081

  3. SECTM1 Produced by Tumor Cells Attracts Human Monocytes Via CD7-mediated Activation of the PI3K Pathway

    PubMed Central

    Wang, Tao; Ge, Yingbin; Xiao, Min; Lopez-Coral, Alfonso; Li, Ling; Roesch, Alexander; Huang, Catherine; Alexander, Peter; Vogt, Thomas; Xu, Xiaowei; Hwang, Wei-Ting; Lieu, Melissa; Belser, Eric; Liu, Rui; Somasundaram, Rajasekharan; Herlyn, Meenhard; Kaufman, Russel E.

    2013-01-01

    Tumor-associated macrophages (TAMs) play essential roles in tumor progression and metastasis. Tumor cells recruit myeloid progenitors and monocytes to the tumor site, where they differentiate into TAMs; however, this process is not well studied in humans. Here we show that human CD7, a T cell and NK cell receptor, is highly expressed by monocytes and macrophages. Expression of CD7 decreases in M-CSF differentiated macrophages and in Melanoma-conditioned Medium Induced Macrophages (MCMI/Mϕ) in comparison to monocytes. A ligand for CD7, SECTM1 (Secreted and transmembrane protein 1), is highly expressed in many tumors, including melanoma cells. We show that SECTM1 binds to CD7 and significantly increases monocyte migration by activation of the PI3K pathway. In human melanoma tissues, tumor-infiltrating macrophages expressing CD7 are present. These melanomas, with CD7-positive inflammatory cell infiltrations, frequently highly express SECTM1, including an N-terminal, soluble form, which can be detected in the sera of metastatic melanoma patients but not in normal sera. Taken together, our data demonstrate that CD7 is present on monocytes and tumor macrophages, and that its ligand, SECTM1, is frequently expressed in corresponding melanoma tissues, possibly acting as a chemoattractant for monocytes to modulate the melanoma microenvironment. PMID:24157461

  4. A novel hybrid aspirin-NO-releasing compound inhibits TNFalpha release from LPS-activated human monocytes and macrophages

    PubMed Central

    Turnbull, Catriona M; Marcarino, Paolo; Sheldrake, Tara A; Lazzarato, Loretta; Cena, Clara; Fruttero, Roberta; Gasco, Alberto; Fox, Sarah; Megson, Ian L; Rossi, Adriano G

    2008-01-01

    Background The cytoprotective nature of nitric oxide (NO) led to development of NO-aspirins in the hope of overcoming the gastric side-effects of aspirin. However, the NO moiety gives these hybrids potential for actions further to their aspirin-mediated anti-platelet and anti-inflammatory effects. Having previously shown that novel NO-aspirin hybrids containing a furoxan NO-releasing group have potent anti-platelet effects, here we investigate their anti-inflammatory properties. Here we examine their effects upon TNFα release from lipopolysaccharide (LPS)-stimulated human monocytes and monocyte-derived macrophages and investigate a potential mechanism of action through effects on LPS-stimulated nuclear factor-kappa B (NF-κB) activation. Methods Peripheral venous blood was drawn from the antecubital fossa of human volunteers. Mononuclear cells were isolated and cultured. The resultant differentiated macrophages were treated with pharmacologically relevant concentrations of either a furoxan-aspirin (B8, B7; 10 μM), their respective furazan NO-free counterparts (B16, B15; 10 μM), aspirin (10 μM), existing nitroaspirin (NCX4016; 10 μM), an NO donor (DEA/NO; 10 μM) or dexamethasone (1 μM), in the presence and absence of LPS (10 ng/ml; 4 h). Parallel experiments were conducted on undifferentiated fresh monocytes. Supernatants were assessed by specific ELISA for TNFα release and by lactate dehydrogenase (LDH) assay for cell necrosis. To assess NF-κB activation, the effects of the compounds on the loss of cytoplasmic inhibitor of NF-κB, IκBα (assessed by western blotting) and nuclear localisation (assessed by immunofluorescence) of the p65 subunit of NF-κB were determined. Results B8 significantly reduced TNFα release from LPS-treated macrophages to 36 ± 10% of the LPS control. B8 and B16 significantly inhibited monocyte TNFα release to 28 ± 5, and 49 ± 9% of control, respectively. The B8 effect was equivalent in magnitude to that of dexamethasone, but

  5. Protein tyrosine kinase activity is essential for Fc gamma receptor-mediated intracellular killing of Staphylococcus aureus by human monocytes.

    PubMed Central

    Zheng, L; Nibbering, P H; Zomerdijk, T P; van Furth, R

    1994-01-01

    Our previous study revealed that the intracellular killing of Staphylococcus aureus by human monocytes after cross-linking Fc gamma receptor I (Fc gamma RI) or Fc gamma RII is a phospholipase C (PLC)-dependent process. The aim of the present study was to investigate whether protein tyrosine kinase (PTK) activity plays a role in the Fc gamma R-mediated intracellular killing of bacteria and activation of PLC in these cells. The results showed that phagocytosis of bacteria by monocytes was not affected by the PTK inhibitors genistein and tyrphostin-47. The intracellular killing of S. aureus by monocytes after cross-linking Fc gamma RII or Fc gamma RII with anti-Fc gamma R monoclonal antibody and a bridging antibody or with human immunoglobulin G (IgG) was inhibited by these compounds in a dose-dependent fashion. The production of O2- by monocytes after stimulation with IgG or IgG-opsonized S. aureus was almost completely blocked by the PTK inhibitor. These results indicate that inhibition of PTK impairs the oxygen-dependent bactericidal mechanisms of monocytes. Genistein and tyrphostin-47, which do not affect the enzymatic activity of purified PLC, prevented activation of PLC after cross-linking Fc gamma RI or Fc gamma RII, measured as an increase in the intracellular inositol 1,4,5-trisphosphate concentration. Cross-linking Fc gamma RI or Fc gamma RII induced rapid tyrosine phosphorylation of several proteins in monocytes, one of which was identified as PLC-gamma 1, and the phosphorylation could be completely blocked by PTK inhibitors, leading to the conclusion that activation of PLC after cross-linking Fc gamma R in monocytes is regulated by PTK activity. Together, these results demonstrate that PTK activity is essential for the activation of PLC which is involved in the Fc gamma R-mediated intracellular killing of S. aureus by human monocytes. Images PMID:7927687

  6. 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

    Wu, Shu-En; Miller, William E

    2015-09-01

    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

  7. Control of pro-inflammatory cytokine release from human monocytes with the use of an interleukin-10 monoclonal antibody.

    PubMed

    Patel, Hardik; Davidson, Dennis

    2014-01-01

    The monocytes (MONOs) can be considered as "double-edge swords"; they have both important pro-inflammatory and anti-inflammatory functions manifested in part by cytokine production and release. Although MONOs are circulating cells, they are the major precursors of a variety of tissue-specific immune cells such as the alveolar macrophage, dendritic cells, microglial cells, and Kupffer cells. Unlike the polymorphonuclear leukocyte, which produces no or very little interleukin-10 (IL-10), the monocyte can produce this potent anti-inflammatory cytokine to control inflammation. IL-10, on an equimolar basis, is a more potent inhibitor of pro-inflammatory cytokines produced by monocytes than many anti-inflammatory glucocorticoids which are used clinically. This chapter describes how to isolate monocytes from human blood and the use of IL-10 monoclonal antibody to determine the effect and timing of endogenous IL-10 release on the production and release of pro-inflammatory cytokines. PMID:24908297

  8. Transcriptional Profiling of Human Monocytes Identifies the Inhibitory Receptor CD300a as Regulator of Transendothelial Migration

    PubMed Central

    Bottino, Cristina; Gerke, Volker

    2013-01-01

    Local inflammatory responses are characterized by the recruitment of circulating leukocytes from the blood to sites of inflammation, a process requiring the directed migration of leukocytes across the vessel wall and hence a penetration of the endothelial lining. To identify underlying signalling events and novel factors involved in these processes we screened for genes differentially expressed in human monocytes following their adhesion to and passage through an endothelial monolayer. Functional annotation clustering of the genes identified revealed an overrepresentation of those associated with inflammation/immune response, in particular early monocyte to macrophage differentiation. Among the gene products so far not implicated in monocyte transendothelial migration was the inhibitory immune receptor CD300a. CD300a mRNA and protein levels were upregulated following transmigration and engagement of the receptor by anti-CD300a antibodies markedly reduced monocyte transendothelial migration. In contrast, siRNA mediated downregulation of CD300a in human monocytes increased their rate of migration. CD300a colocalized and cosedimented with actin filaments and, when activated, caused F-actin cytoskeleton alterations. Thus, monocyte transendothelial migration is accompanied by an elevation of CD300a which serves an inhibitory function possibly required for termination of the actual transmigration. PMID:24058511

  9. Moraxella catarrhalis lipooligosaccharide selectively upregulates ICAM-1 expression on human monocytes and stimulates adjacent naïve monocytes to produce TNF-alpha through cellular cross-talk.

    PubMed

    Xie, Hang; Gu, Xin-Xing

    2008-07-01

    To elucidate the role of Moraxella catarrhalis lipooligosaccharide (LOS) in otitis media with effusion (OME), the effects of LOS on adhesion antigens of human monocytes were investigated. M. catarrhalis LOS selectively enhanced intercellular adhesion molecule 1 (ICAM-1 or CD54) expression on human monocytes by significantly increasing both the surface expression intensity and the percentage of ICAM-1(+) cells. ICAM-1 upregulation on human monocytes by the LOS required surface CD14, TLR4, NF-kappaB p65 and c-Jun N-terminal kinase (JNK) activity. Our study also revealed that the LOS-induced surface ICAM-1 expression was partially mediated through a TNF-alpha dependent autocrine mechanism and could be further augmented by lipopolysaccharide-binding protein in serum. In addition, M. catarrhalis LOS also stimulated human monocytes to produce pro-inflammatory cytokines in both TLR4- and CD14-dependent pathways. Our results also indicated that enhanced surface ICAM-1 expression on monocytes may hinder their adherence to the lung epithelial monolayer. Furthermore, the LOS-activated human monocytes secreted a significantly high level of IL-8, and could stimulate adjacent naïve monocytes to produce TNF-alpha which was partially mediated via membrane ICAM-1 and IL-8/IL-8RA. These results suggest that M. catarrhalis LOS could induce excessive middle ear inflammation through a cellular cross-talk mechanism during OME. PMID:18363879

  10. Expression and Function of Semaphorin 3A and Its Receptors in Human Monocyte-derived Macrophages

    PubMed Central

    Ji, Jong-Dae; Park-Min, Kyung-Hyun; Ivashkiv, Lionel B.

    2016-01-01

    Semaphorins are a large family of secreted and membrane-bound proteins. Recently, several roles of semaphorins in the immune system have emerged. Several semaphorins and their receptors are expressed in a variety of lymphoid and myeloid cells and affect immune cell functions, including cell proliferation, differentiation, chemotaxis, and cytokine production. However, the roles of class 3 semaphorins in human myeloid cells are not well known. Here we examined the regulation of expression of class 3 semaphorins and their receptors by inflammatory stimuli and their function in human macrophages. We show that the expression of Sema3A receptors (neuropilin-1 (NRP-1), NRP-2, plexin A1, plexin A2 and plexin A3) significantly increased during M-CSF-mediated differentiation of monocytes into macrophages under conditions that promote an M2 alternatively activated macrophage phenotype. Consistent with increased NRP-1 expression, cell surface binding of Sema3A increased during M2 differentiation. IFN-γ and LPS that promote classical M1 macrophage activation affected expression of NRP-1, NRP-2 and plexin A1. IFN-γ decreased NRP-1 expression and LPS suppressed NRP-2 and plexin A1 expression. Furthermore we show that Sema3A induced apoptosis in monocyte-derived macrophages, and cooperated with anti-Fas CH11 antibody to augment apoptosis. Our results suggest Sema3A plays a role in induction of apoptosis in monocyte-derived macrophages that are resistant to Fas-induced apoptosis and that its function can be modulated in inflammatory conditions. PMID:19480842

  11. ERK5 pathway regulates transcription factors important for monocytic differentiation of human myeloid leukemia cells.

    PubMed

    Wang, Xuening; Pesakhov, Stella; Harrison, Jonathan S; Danilenko, Michael; Studzinski, George P

    2014-07-01

    Mitogen-activated protein kinases (MAPKs) are important transducers of external signals for cell growth, survival, and other cellular responses including cell differentiation. Several MAPK cascades are known with the MEK1/2-ERK1/2, JNK, and p38MAPKs receiving most attention, but the role of MEK5-ERK5 in intracellular signaling deserves more scrutiny, as this pathway transmits signals that can complement ERK/2 signaling. We hypothesized that the ERK5 pathway plays a role in the control of monocytic differentiation, which is disturbed in myeloid leukemia. We therefore examined the cellular phenotype and key molecular events which occur when human myeloid leukemia cells, acute (AML) or chronic (CML), are forced to differentiate by vitamin D derivatives (VDDs). This study was performed using established cell lines HL60 and U937, and primary cultures of blasts from 10 patients with ML. We found that ERK5 and its direct downstream target transcription factor MEF2C are upregulated by 1,25D in parallel with monocytic differentiation. Further, inhibition of ERK5 activity by specific pharmacological agents BIX02189 and XMD8-92 alters the phenotype of these cells by reducing the abundance of the VDD-induced surface monocytic marker CD14, and concomitantly increasing surface expression of the general myeloid marker CD11b. Similar results were obtained when the expression of ERK5 was reduced by siRNA or short hairpin (sh) RNA. ERK5 inhibition resulted in an expected decrease in MEF2C activation. We also found that in AML cells the transcription factor C/EBPβ is positively regulated, while C/EBPα is negatively regulated by ERK5. These findings provide new understanding of dysregulated differentiation in human myeloid leukemia. PMID:24264602

  12. Spin trapping evidence for myeloperoxidase-dependent hydroxyl radical formation by human neutrophils and monocytes

    SciTech Connect

    Ramos, C.L.; Pou, S.; Britigan, B.E.; Cohen, M.S.; Rosen, G.M. )

    1992-04-25

    Using the electron spin resonance/spin trapping system, 4-pyridyl 1-oxide N-tert-butylnitrone (4-POBN)/ethanol, hydroxyl radical was detected as the alpha-hydroxyethyl spin trapped adduct of 4-POBN, 4-POBN-CH(CH3)OH, from phorbol 12-myristate 13-acetate-stimulated human neutrophils and monocytes without the addition of supplemental iron. 4-POBN-CH(CH3)OH was stable in the presence of a neutrophil-derived superoxide flux. Hydroxyl radical formation was inhibited by treatment with superoxide dismutase, catalase, and azide. Treatment with a series of transition metal chelators did not appreciably alter 4-POBN-CH(CH3)OH, which suggested that hydroxyl radical generation was mediated by a mechanism independent of the transition metal-catalyzed Haber-Weiss reaction. Kinetic differences between transition metal-dependent and -independent mechanisms of hydroxyl radical generation by stimulated neutrophils were demonstrated by a greater rate of 4-POBN-CH(CH3)-OH accumulation in the presence of supplemental iron. Detection of hydroxyl radical from stimulated monocyte-derived macrophages, which lack myeloperoxidase, required the addition of supplemental iron. The addition of purified myeloperoxidase to an enzymatic superoxide generating system resulted in the detection of hydroxyl radical that was dependent upon the presence of chloride and was inhibited by superoxide dismutase, catalase, and azide. These findings implicated the reaction of hypochlorous acid and superoxide to produce hydroxyl radical. 4-POBN-CH(CH3)OH was not observed upon stimulation of myeloperoxidase-deficient neutrophils, whereas addition of myeloperoxidase to the reaction mixture resulted in the detection of hydroxyl radical. These results support the ability of human neutrophils and monocytes to generate hydroxyl radical through a myeloperoxidase-dependent mechanism.

  13. ERK5 Pathway Regulates Transcription Factors Important for Monocytic Differentiation of Human Myeloid Leukemia Cells†

    PubMed Central

    Wang, Xuening; Pesakhov, Stella; Harrison, Jonathan S; Danilenko, Michael; Studzinski, George P

    2014-01-01

    Mitogen-activated protein kinases (MAPKs) are important transducers of external signals for cell growth, survival and other cellular responses including cell differentiation. Several MAPK cascades are known with the MEK1/2-ERK1/2, JNK, and p38MAPKs receiving most attention, but the role of MEK5-ERK5 in intracellular signaling deserves more scrutiny, as this pathway transmits signals that can complement ERK/2 signaling. We hypothesized that the ERK5 pathway plays a role in the control of monocytic differentiation, which is disturbed in myeloid leukemia. We therefore examined the cellular phenotype and key molecular events which occur when human myeloid leukemia cells, acute (AML) or chronic (CML), are forced to differentiate by vitamin D derivatives (VDDs). This study was performed using established cell lines HL60 and U937, and primary cultures of blasts from 10 patients with ML. We found that ERK5 and its direct downstream target transcription factor MEF2C are upregulated by 1,25D in parallel with monocytic differentiation. Further, inhibition of ERK5 activity by specific pharmacological agents BIX02189 and XMD8-92 alters the phenotype of these cells by reducing the abundance of the VDD-induced surface monocytic marker CD14, and concomitantly increasing surface expression of the general myeloid marker CD11b. Similar results were obtained when the expression of ERK5 was reduced by siRNA or short hairpin (sh) RNA. ERK5 inhibition resulted in an expected decrease in MEF2C activation. We also found that in AML the transcription factor C/EBPβ is positively regulated, while C/EBPα is negatively regulated by ERK5. These findings provide new understanding of dysregulated differentiation in human myeloid leukemia. PMID:24264602

  14. Human Cytomegalovirus Promotes Survival of Infected Monocytes via a Distinct Temporal Regulation of Cellular Bcl-2 Family Proteins

    PubMed Central

    Collins-McMillen, Donna; Kim, Jung Heon; Nogalski, Maciej T.; Stevenson, Emily V.; Caskey, Joshua R.; Cieply, Stephen J.

    2015-01-01

    ABSTRACT Monocytes play a key role in the hematogenous dissemination of human cytomegalovirus (HCMV) to target organ systems. To infect monocytes and reprogram them to deliver infectious virus, HCMV must overcome biological obstacles, including the short life span of monocytes and their antiviral proapoptotic response to infection. We have shown that virally induced upregulation of cellular Mcl-1 promotes early survival of HCMV-infected monocytes, allowing cells to overcome an early apoptotic checkpoint at around 48 h postinfection (hpi). Here, we demonstrate an HCMV-dependent shift from Mcl-1 as the primary antiapoptotic player to the related protein, Bcl-2, later during infection. Bcl-2 was upregulated in HCMV-infected monocytes beginning at 48 hpi. Treatment with the Bcl-2 antagonist ABT-199 only reduced the prosurvival effects of HCMV in target monocytes beginning at 48 hpi, suggesting that Mcl-1 controls survival prior to 48 hpi, while Bcl-2 promotes survival after 48 hpi. Although Bcl-2 was upregulated following viral binding/signaling through cellular integrins (compared to Mcl-1, which is upregulated through binding/activation of epidermal growth factor receptor [EGFR]), it functioned similarly to Mcl-1, adopting the early role of Mcl-1 in preventing caspase-3 cleavage/activation. This distinct, HCMV-induced shift from Mcl-1 to Bcl-2 occurs in response to a cellular upregulation of proapoptotic Bax, as small interfering RNA (siRNA)-mediated knockdown of Bax reduced the upregulation of Bcl-2 in infected monocytes and rescued the cells from the apoptotic effects of Bcl-2 inhibition. Our data demonstrate a distinct survival strategy whereby HCMV induces a biphasic regulation of cellular Bcl-2 proteins to promote host cell survival, leading to viral dissemination and the establishment of persistent HCMV infection. IMPORTANCE Hematogenous dissemination of HCMV via infected monocytes is a crucial component of the viral survival strategy and is required for the

  15. Human glioblastoma-associated microglia/monocytes express a distinct RNA profile compared to human control and murine samples.

    PubMed

    Szulzewsky, Frank; Arora, Sonali; de Witte, Lot; Ulas, Thomas; Markovic, Darko; Schultze, Joachim L; Holland, Eric C; Synowitz, Michael; Wolf, Susanne A; Kettenmann, Helmut

    2016-08-01

    Glioblastoma (GBM) is the most aggressive brain tumor in adults. It is strongly infiltrated by microglia and peripheral monocytes that support tumor growth. In the present study we used RNA sequencing to compare the expression profile of CD11b(+) human glioblastoma-associated microglia/monocytes (hGAMs) to CD11b(+) microglia isolated from non-tumor samples. Hierarchical clustering and principal component analysis showed a clear separation of the two sample groups and we identified 334 significantly regulated genes in hGAMs. In comparison to human control microglia hGAMs upregulated genes associated with mitotic cell cycle, cell migration, cell adhesion, and extracellular matrix organization. We validated the expression of several genes associated with extracellular matrix organization in samples of human control microglia, hGAMs, and the hGAMs-depleted fraction via qPCR. The comparison to murine GAMs (mGAMs) showed that both cell populations share a significant fraction of upregulated transcripts compared with their respective controls. These genes were mostly related to mitotic cell cycle. However, in contrast to murine cells, human GAMs did not upregulate genes associated to immune activation. Comparison of human and murine GAMs expression data to several data sets of in vitro-activated human macrophages and murine microglia showed that, in contrast to mGAMs, hGAMs share a smaller overlap to these data sets in general and in particular to cells activated by proinflammatory stimulation with LPS + INFγ or TNFα. Our findings provide new insights into the biology of human glioblastoma-associated microglia/monocytes and give detailed information about the validity of murine experimental models. GLIA 2016 GLIA 2016;64:1416-1436. PMID:27312099

  16. Binding immunoglobulin protein-treated peripheral blood monocyte-derived dendritic cells are refractory to maturation and induce regulatory T-cell development.

    PubMed

    Corrigall, Valerie M; Vittecoq, Olivier; Panayi, Gabriel S

    2009-10-01

    Binding immunoglobulin protein (BiP) has been shown previously to have immunomodulatory functions. Herein we investigated whether BiP could affect the differentiation of monocytes into dendritic cells (DCs) and thence the development of regulatory T cells. Peripheral blood monocyte-derived DCs were matured with lipopolysaccharide in the presence or absence of BiP. DC development and T-cell changes were monitored by flow cytometry and regulatory T-cell function was measured by uptake of tritiated thymidine. More BiP-treated DCs (DC((BiP))s) expressed amounts of intracellular indoleamine 2,3-dioxygenase (IDO) and cell surface leucocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1), retained CD14 expression but down-regulated expression of human leucocyte antigen (HLA)-DR and CD86, and produced copious amounts of interleukin (IL)-10, when compared with control DCs. T cells co-cultured with DC((BiP))s developed regulatory function with increased surface expression of CD4(+) CD25(hi) CD27(hi) but with no concomitant increase in forkhead box P3 (Foxp3). These T cells also showed significantly higher levels of intracellular cytotoxic T-lymphocyte antigen (CTLA)-4. The latter could be inhibited by the presence of the IDO inhibitor 1 methyl tryptophan. The addition of neutralizing anti-IL-10 antibody or the specific mitogen-activated protein kinase (MAPK) p38 inhibitor SB203580 reversed the inhibition of DC differentiation by BiP. In conclusion, BiP is an immunomodulator able to arrest inflammation through induction of tolerogenic DCs and subsequent generation of T regulatory cells. PMID:19740378

  17. Differential regulation of human T cell responsiveness by mucosal versus blood monocytes.

    PubMed

    Qiao, L; Braunstein, J; Golling, M; Schürmann, G; Autschbach, F; Möller, P; Meuer, S

    1996-04-01

    Human intestinal T lymphocytes are constantly exposed to a large number of foreign antigens without developing a systemic immune response. One crucial mechanisms leading to this intestinal hyporesponsiveness is based on impaired signal transduction through the T cell receptor/CD3 complex in lamina propria T lymphocytes (LP-T). In this study, we addressed the question whether a lack of co-stimulatory/progression signals might also contribute to LP-T hyporesponsiveness. To this end, isolated human monocyte populations from the intestinal lamina propria were obtained and their phenotypes as well as their capacity to promote T cell activation studied. Here, we demonstrate that lamina propria macrophages (LP-MO), in contrast to peripheral blood monocytes (PB-MO), do not support proliferation of either LP-T or PB-T. This may be due to the low expression of ligands (CD54, CD58, CD80) for the T cell accessory receptors CD11/18, CD2 and CD28/CTLA-4 on mucosal macrophages. Thus, down-regulation of both recognition/competence and co-stimulatory/progression signals contribute to intestinal hypo- or unresponsiveness. PMID:8625989

  18. Proteome analysis of human monocytic THP-1 cells primed with oxidized low-density lipoproteins.

    PubMed

    Kang, Jeong Han; Kim, Hyun Tae; Choi, Myung-Sook; Lee, Won Ha; Huh, Tae-Lin; Park, Yong Bok; Moon, Byung Jo; Kwon, Oh-Shin

    2006-02-01

    Native low-density lipoprotein (LDL) and oxidized LDL (oxLDL) possess a wide variety of biological properties, and play a central role in atherogenesis. In this study, we used a proteomic analysis of human monocyte THP-1 cells induced with oxLDL or with LDL, to identify proteins potentially involved in atherosclerotic processes. Of the 2500 proteins detected, 93 were differentially expressed as a result of priming with LDL or oxLDL. The proteins were unambiguously identified by comparing the masses of their tryptic peptides with those of all known proteins using MALDI-TOF MS and the NCBI database. The largest differences in expression were observed for vimentin (94-fold increase), meningioma-expressed antigen 6 (48-fold increase), serine/threonine protein phosphatase 2A (40-fold increase), and beta-1,3-galactosyltransferase (15-fold increase). In contrast, the abundance of an unnamed protein product and phosphogluconate dehydrogenase decreased 30-fold and 25-fold, respectively. The expression of some selected proteins was confirmed by Western blot and RT-PCR analyses. The proteins identified in this study are attractive candidates for further biomarker research. This description of the altered protein profiles induced by oxLDL in human monocytes will support functional studies of the macrophage-derived foam cells involved in the pathogenesis of atherosclerosis. PMID:16402358

  19. Age-Related Gene Expression Differences in Monocytes from Human Neonates, Young Adults, and Older Adults.

    PubMed

    Lissner, Michelle M; Thomas, Brandon J; Wee, Kathleen; Tong, Ann-Jay; Kollmann, Tobias R; Smale, Stephen T

    2015-01-01

    A variety of age-related differences in the innate and adaptive immune systems have been proposed to contribute to the increased susceptibility to infection of human neonates and older adults. The emergence of RNA sequencing (RNA-seq) provides an opportunity to obtain an unbiased, comprehensive, and quantitative view of gene expression differences in defined cell types from different age groups. An examination of ex vivo human monocyte responses to lipopolysaccharide stimulation or Listeria monocytogenes infection by RNA-seq revealed extensive similarities between neonates, young adults, and older adults, with an unexpectedly small number of genes exhibiting statistically significant age-dependent differences. By examining the differentially induced genes in the context of transcription factor binding motifs and RNA-seq data sets from mutant mouse strains, a previously described deficiency in interferon response factor-3 activity could be implicated in most of the differences between newborns and young adults. Contrary to these observations, older adults exhibited elevated expression of inflammatory genes at baseline, yet the responses following stimulation correlated more closely with those observed in younger adults. Notably, major differences in the expression of constitutively expressed genes were not observed, suggesting that the age-related differences are driven by environmental influences rather than cell-autonomous differences in monocyte development. PMID:26147648

  20. Development of human connective tissue mast cells from purified blood monocytes.

    PubMed Central

    Czarnetzki, B M; Figdor, C G; Kolde, G; Vroom, T; Aalberse, R; de Vries, J E

    1984-01-01

    Highly purified subfractions of human peripheral blood monocytes, when cultured in the presence of 30% L cell supernatant and 30% horse serum, assumed all the characteristics that define human connective tissue mast cells. After three weeks of culture, 75% of the cells developed metachromasia and granular chloroacetate esterase staining, and their intracellular histamine levels increased from 0.0 to 50.5 ng/10(6) cells. On electron microscopy, the cells developed intracytoplasmic granules with all the features typical for mature and immature mast cells. Cultured cells bound 55 pg 125I-IgE/10(6) cells, while labelling was negligible with cells prior to culture and with heat-denatured 125I-IgE. Fluorescent staining with anti-IgE increased slightly as well, while staining with monoclonal anti-monocyte and anti-HLA-Dr markers decreased. Purified lymphocytes did not assume mast cell characteristics, and lymphokines did not induce or enhance in vitro mast cell development or IgE binding. The data therefore further support the concept that connective tissue mast cells arise from the monocytoid lineage. Images Figure 1 PMID:6698581

  1. Uptake of exogenous free cholesterol induces upregulation of tissue factor expression in human monocyte-derived macrophages.

    PubMed Central

    Lesnik, P; Rouis, M; Skarlatos, S; Kruth, H S; Chapman, M J

    1992-01-01

    Lipid-laden macrophages present as foam cells may contribute to the hyperthrombotic state of human atherosclerotic lesions by the production of tissue factor (TF). We investigated the effect of exogenous nonlipoprotein cholesterol on the expression of TF by human monocyte-derived macrophages in culture. Nonlipoprotein cholesterol at 50 micrograms/ml increased TF activity 4-fold; TF induction was dose- and time-dependent. Expression of TF activity was positively correlated with the free cholesterol content of monocyte-derived macrophages, was increased upon inhibition of cholesterol esterification, and reflected de novo synthesis of TF protein. TF expression in cholesterol-loaded macrophages remained sensitive to stimulation (approximately 12-fold) by bacterial lipopolysaccharide, indicating that intracellular free cholesterol and lipopolysaccharide act by distinct mechanisms in inducing TF procoagulant activity. Our results suggest that loading human monocyte-derived macrophages with free cholesterol induces upregulation of TF expression, thereby contributing to thrombus formation at sites of plaque rupture. Images PMID:1438222

  2. α1-adrenergic receptors positively regulate Toll-like receptor cytokine production from human monocytes and macrophages.

    PubMed

    Grisanti, Laurel A; Woster, Andrew P; Dahlman, Julie; Sauter, Edward R; Combs, Colin K; Porter, James E

    2011-08-01

    Catecholamines released from the sympathetic nervous system in response to stress or injury affect expression of inflammatory cytokines generated by immune cells. α(1)-Adrenergic receptors (ARs) are expressed on innate immune cell populations, but their subtype expression patterns and signaling characteristics are not well characterized. Primary human monocytes, a human monocytic cell line, and monocyte-derived macrophage cells were used to measure expression of the proinflammatory mediator interleukin (IL)-1β responding to lipopolysaccharide (LPS) in the presence or absence of α(1)-AR activation. Based on our previous findings, we hypothesized that α(1)-AR stimulation on innate immune cells positively regulates LPS-initiated IL-1β production. IL-1β production in response to LPS was synergistically higher for both monocytes and macrophages in the presence of the selective α(1)-AR agonist (R)-(-)-phenylephrine hydrochloride (PE). This synergistic IL-1β response could be blocked with a selective α(1)-AR antagonist as well as inhibitors of protein kinase C (PKC). Radioligand binding studies characterized a homogenous α(1B)-AR subtype population on monocytes, which changed to a heterogeneous receptor subtype expression pattern when differentiated to macrophages. Furthermore, increased p38 mitogen-activated protein kinase (MAPK) activation was observed only with concurrent PE and LPS stimulation, peaking after 120 and 30 min in monocytes and macrophages, respectively. Blocking the PKC/p38 MAPK signaling pathway in both innate immune cell types inhibited the synergistic IL-1β increase observed with concurrent PE and LPS treatments. This study characterizes α(1)-AR subtype expression on both human monocyte and macrophage cells and illustrates a mechanism by which increased IL-1β production can be modulated by α(1)-AR input. PMID:21571945

  3. Monoclonal antibody to a subset of human monocytes found only in the peripheral blood and inflammatory tissues

    SciTech Connect

    Zwadlo, G.; Schlegel, R.; Sorg, C.

    1986-07-15

    A monoclonal antibody is described that was generated by immunizing mice with cultured human blood monocytes. The antibody (27E10) belongs to the IgG1 subclass and detects a surface antigen at M/sub r/ 17,000 that is found on 20% of peripheral blood monocytes. The antigen is increasingly expressed upon culture of monocytes, reaching a maximum between days 2 and 3. Stimulation of monocytes with interferon-..gamma.. (IFN-..gamma..), 12-O-tetradecanoyl-phorbol-13-acetate (TPA), and lipopolysaccharide (LPS) Ylalanine (fMLP) increased the 27E10 antigen density. The amount of 27E10-positive cells is not or is only weakly affected. The antigen is absent from platelets, lymphotyces, and all tested human cell lines, yet it cross-reacts with 15% of freshly isolated granulocytes. By using the indirect immunoperoxidase technique, the antibody is found to be negative on cryostat sections of normal human tissue (skin, lung, and colon) and positive on only a few monocyte-like cells in liver and on part of the cells of the splenic red pulp. In inflammatory tissue, however, the antibody is positive on monocytes/macrophages and sometimes on endothelial cells and epidermal cells, depending on the stage and type of inflammation, e.g., BCG ranulomas are negative, whereas psoriasis vulgaris, atopic dermatitis, erythrodermia, pressure urticaria, and periodontitis contain positively staining cells. In contact eczemas at different times after elicitation (6 hr, 24 hr, and 72 hr), the 27E10 antigen is seen first after 24 hr on a few infiltrating monocytes/macrophages, which increase in numbers after 72 hr.

  4. Genetics and Beyond – The Transcriptome of Human Monocytes and Disease Susceptibility

    PubMed Central

    Zeller, Tanja; Wild, Philipp; Szymczak, Silke; Rotival, Maxime; Schillert, Arne; Castagne, Raphaele; Maouche, Seraya; Germain, Marine; Lackner, Karl; Rossmann, Heidi; Eleftheriadis, Medea; Sinning, Christoph R.; Schnabel, Renate B.; Lubos, Edith; Mennerich, Detlev; Rust, Werner; Perret, Claire; Proust, Carole; Nicaud, Viviane; Loscalzo, Joseph; Hübner, Norbert; Tregouet, David; Münzel, Thomas; Ziegler, Andreas; Tiret, Laurence

    2010-01-01

    Background Variability of gene expression in human may link gene sequence variability and phenotypes; however, non-genetic variations, alone or in combination with genetics, may also influence expression traits and have a critical role in physiological and disease processes. Methodology/Principal Findings To get better insight into the overall variability of gene expression, we assessed the transcriptome of circulating monocytes, a key cell involved in immunity-related diseases and atherosclerosis, in 1,490 unrelated individuals and investigated its association with >675,000 SNPs and 10 common cardiovascular risk factors. Out of 12,808 expressed genes, 2,745 expression quantitative trait loci were detected (P<5.78×10−12), most of them (90%) being cis-modulated. Extensive analyses showed that associations identified by genome-wide association studies of lipids, body mass index or blood pressure were rarely compatible with a mediation by monocyte expression level at the locus. At a study-wide level (P<3.9×10−7), 1,662 expression traits (13.0%) were significantly associated with at least one risk factor. Genome-wide interaction analyses suggested that genetic variability and risk factors mostly acted additively on gene expression. Because of the structure of correlation among expression traits, the variability of risk factors could be characterized by a limited set of independent gene expressions which may have biological and clinical relevance. For example expression traits associated with cigarette smoking were more strongly associated with carotid atherosclerosis than smoking itself. Conclusions/Significance This study demonstrates that the monocyte transcriptome is a potent integrator of genetic and non-genetic influences of relevance for disease pathophysiology and risk assessment. PMID:20502693

  5. Retinoid-Dependent Restriction of Human Immunodeficiency Virus Type 1 Replication in Monocytes/Macrophages

    PubMed Central

    Hanley, Timothy M.; Kiefer, Heather L. B.; Schnitzler, Aletta C.; Marcello, Jennifer E.; Viglianti, Gregory A.

    2004-01-01

    Vitamin A deficiency has been correlated with increased severity of human immunodeficiency virus type 1 (HIV-1)-associated disease. Moreover, vitamin A supplementation can reduce AIDS-associated morbidity and mortality. Our group and others have shown that retinoids, the bioactive metabolites of vitamin A, repress HIV-1 replication in monocytic cell lines and primary macrophages by blocking long-terminal-repeat (LTR)-directed transcription. Based on these studies, we hypothesize that retinoids are natural repressors of HIV-1 in vivo. We show here that all-trans-retinoic acid (RA)-mediated repression of HIV-1 activation requires pretreatment for at least 12 h and is blocked by the protein synthesis inhibitors cycloheximide and puromycin. Studies of the kinetics of RA-mediated repression in U1 cells and primary monocyte-derived macrophages (MDMs) reveal that the repressive effects of RA on HIV-1 expression are long-lasting but reversible. We demonstrate that HIV-1 expression is activated when U1 cells or MDMs are cultured in retinoid-free synthetic medium and show that physiological concentrations of RA repress this activation. In addition, the synthetic pan-retinoic acid receptor antagonist BMS-204 493 activates HIV-1 replication in U1 cells in a dose-dependent manner, suggesting that RA-induced transactivation of cellular gene expression is required for HIV-1 repression. Together, these data support the hypothesis that retinoids present in tissue culture media in vitro and serum in vivo maintain HIV-1 in a transcriptionally repressed state in monocytes/macrophages. PMID:14990701

  6. Systems toxicology-based assessment of the candidate modified risk tobacco product THS2.2 for the adhesion of monocytic cells to human coronary arterial endothelial cells.

    PubMed

    Poussin, Carine; Laurent, Alexandra; Peitsch, Manuel C; Hoeng, Julia; De Leon, Hector

    2016-01-01

    Alterations of endothelial adhesive properties by cigarette smoke (CS) can progressively favor the development of atherosclerosis which may cause cardiovascular disorders. Modified risk tobacco products (MRTPs) are tobacco products developed to reduce smoking-related risks. A systems biology/toxicology approach combined with a functional in vitro adhesion assay was used to assess the impact of a candidate heat-not-burn technology-based MRTP, Tobacco Heating System (THS) 2.2, on the adhesion of monocytic cells to human coronary arterial endothelial cells (HCAECs) compared with a reference cigarette (3R4F). HCAECs were treated for 4h with conditioned media of human monocytic Mono Mac 6 (MM6) cells preincubated with low or high concentrations of aqueous extracts from THS2.2 aerosol or 3R4F smoke for 2h (indirect treatment), unconditioned media (direct treatment), or fresh aqueous aerosol/smoke extracts (fresh direct treatment). Functional and molecular investigations revealed that aqueous 3R4F smoke extract promoted the adhesion of MM6 cells to HCAECs via distinct direct and indirect concentration-dependent mechanisms. Using the same approach, we identified significantly reduced effects of aqueous THS2.2 aerosol extract on MM6 cell-HCAEC adhesion, and reduced molecular changes in endothelial and monocytic cells. Ten- and 20-fold increased concentrations of aqueous THS2.2 aerosol extract were necessary to elicit similar effects to those measured with 3R4F in both fresh direct and indirect exposure modalities, respectively. Our systems toxicology study demonstrated reduced effects of an aqueous aerosol extract from the candidate MRTP, THS2.2, using the adhesion of monocytic cells to human coronary endothelial cells as a surrogate pathophysiologically relevant event in atherogenesis. PMID:26655683

  7. IL-17A influences essential functions of the monocyte/macrophage lineage and is involved in advanced murine and human atherosclerosis.

    PubMed

    Erbel, Christian; Akhavanpoor, Mohammadreza; Okuyucu, Deniz; Wangler, Susanne; Dietz, Alex; Zhao, Li; Stellos, Konstantinos; Little, Kristina M; Lasitschka, Felix; Doesch, Andreas; Hakimi, Maani; Dengler, Thomas J; Giese, Thomas; Blessing, Erwin; Katus, Hugo A; Gleissner, Christian A

    2014-11-01

    Atherosclerosis is a chronic inflammatory disease. Lesion progression is primarily mediated by cells of the monocyte/macrophage lineage. IL-17A is a proinflammatory cytokine, which modulates immune cell trafficking and is involved inflammation in (auto)immune and infectious diseases. But the role of IL-17A still remains controversial. In the current study, we investigated effects of IL-17A on advanced murine and human atherosclerosis, the common disease phenotype in clinical care. The 26-wk-old apolipoprotein E-deficient mice were fed a standard chow diet and treated either with IL-17A mAb (n = 15) or irrelevant Ig (n = 10) for 16 wk. Furthermore, essential mechanisms of IL-17A in atherogenesis were studied in vitro. Inhibition of IL-17A markedly prevented atherosclerotic lesion progression (p = 0.001) by reducing inflammatory burden and cellular infiltration (p = 0.01) and improved lesion stability (p = 0.01). In vitro experiments showed that IL-17A plays a role in chemoattractance, monocyte adhesion, and sensitization of APCs toward pathogen-derived TLR4 ligands. Also, IL-17A induced a unique transcriptome pattern in monocyte-derived macrophages distinct from known macrophage types. Stimulation of human carotid plaque tissue ex vivo with IL-17A induced a proinflammatory milieu and upregulation of molecules expressed by the IL-17A-induced macrophage subtype. In this study, we show that functional blockade of IL-17A prevents atherosclerotic lesion progression and induces plaque stabilization in advanced lesions in apolipoprotein E-deficient mice. The underlying mechanisms involve reduced inflammation and distinct effects of IL-17A on monocyte/macrophage lineage. In addition, translational experiments underline the relevance for the human system. PMID:25261478

  8. IL-17A Influences Essential Functions of the Monocyte/Macrophage Lineage and Is Involved in Advanced Murine and Human Atherosclerosis

    PubMed Central

    Akhavanpoor, Mohammadreza; Okuyucu, Deniz; Wangler, Susanne; Dietz, Alex; Zhao, Li; Stellos, Konstantinos; Little, Kristina M.; Lasitschka, Felix; Doesch, Andreas; Hakimi, Maani; Dengler, Thomas J.; Giese, Thomas; Blessing, Erwin; Katus, Hugo A.; Gleissner, Christian A.

    2014-01-01

    Atherosclerosis is a chronic inflammatory disease. Lesion progression is primarily mediated by cells of the monocyte/macrophage lineage. IL-17A is a proinflammatory cytokine, which modulates immune cell trafficking and is involved inflammation in (auto)immune and infectious diseases. But the role of IL-17A still remains controversial. In the current study, we investigated effects of IL-17A on advanced murine and human atherosclerosis, the common disease phenotype in clinical care. The 26-wk-old apolipoprotein E–deficient mice were fed a standard chow diet and treated either with IL-17A mAb (n = 15) or irrelevant Ig (n = 10) for 16 wk. Furthermore, essential mechanisms of IL-17A in atherogenesis were studied in vitro. Inhibition of IL-17A markedly prevented atherosclerotic lesion progression (p = 0.001) by reducing inflammatory burden and cellular infiltration (p = 0.01) and improved lesion stability (p = 0.01). In vitro experiments showed that IL-17A plays a role in chemoattractance, monocyte adhesion, and sensitization of APCs toward pathogen-derived TLR4 ligands. Also, IL-17A induced a unique transcriptome pattern in monocyte-derived macrophages distinct from known macrophage types. Stimulation of human carotid plaque tissue ex vivo with IL-17A induced a proinflammatory milieu and upregulation of molecules expressed by the IL-17A–induced macrophage subtype. In this study, we show that functional blockade of IL-17A prevents atherosclerotic lesion progression and induces plaque stabilization in advanced lesions in apolipoprotein E–deficient mice. The underlying mechanisms involve reduced inflammation and distinct effects of IL-17A on monocyte/macrophage lineage. In addition, translational experiments underline the relevance for the human system. PMID:25261478

  9. In vitro Effects of Selected Saponins on the Production and Release of Lysozyme Activity of Human Monocytic and Epithelial Cell Lines

    PubMed Central

    Helal, Racha; Melzig, Matthias F.

    2011-01-01

    Lysozyme is one of the most important factors of innate immunity and a unique enzybiotic in that it exerts not only antibacterial activity, but also antiviral, anti-inflammatory, anticancer and immunomodulatory activities. The purpose of the present study was to investigate whether in vitro exposure to saponins can affect the release and production of lysozyme activity in human monocytic cells THP-1, and in human epithelial cells HT-29. Lysozyme activity levels in cell culture fluids were measured using highly sensitive fluorescence-based lysozyme activity assay. Majority of the examined saponins were demonstrated to stimulate significantly the release of lysozyme activity of monocytes and epithelial cells after one hour treatment at non-toxic concentrations. On the contrary, cells treated with saponins for longer periods up to 72 hours showed tendency to decrease in the secretion and production of lysozyme activity. However, these inhibitory effects of saponins observed with long-term treatment periods were mostly associated with toxic effects of saponins to cells. The results suggested positive contribution of some saponins to lysozyme release of monocytes and epithelial cells upon short exposure. Furthermore, demonstrated ability of these saponins to enhance the release of lysozyme activity can present a new mechanism contribute to explaining important biological characteristics of saponins, including the antibacterial, antiviral, anti-inflammatory or immune-stimulating properties. PMID:21773070

  10. Human caspase-4 and caspase-5 regulate the one-step non-canonical inflammasome activation in monocytes.

    PubMed

    Viganò, Elena; Diamond, Catherine Emma; Spreafico, Roberto; Balachander, Akhila; Sobota, Radoslaw M; Mortellaro, Alessandra

    2015-01-01

    Monocytes promote the early host response to infection releasing key pro-inflammatory cytokines, such as IL-1β. The biologically inactive IL-1β precursor is processed to active form by inflammasomes, multi-protein complexes activating caspase-1. Human monocytes exhibit an unconventional one-step pathway of inflammasome activation in response to lipopolysaccharide (LPS) alone. Although this lineage-restricted mechanism is likely to contribute to the pathology of endotoxin shock, signalling pathways regulating this mechanism are currently unknown. Here we report that caspase-4 and caspase-5 mediate IL-1α and IL-1β release from human monocytes after LPS stimulation. Although caspase-4 remains uncleaved, caspase-5 undergoes rapid processing upon LPS treatment. We also identify an additional caspase-5 cleavage product in LPS-stimulated monocytes, which correlates with IL-1 secretion. This one-step pathway requires Syk activity and Ca(2+) flux instigated by CD14/TLR4-mediated LPS internalization. Identification of caspase-4/5 as the key determinants of one-step inflammasome activation in human monocytes provides potential targets for therapeutic intervention in endotoxin shock. PMID:26508369

  11. Characterization of a receptor for human monocyte-derived neutrophil chemotactic factor/interleukin-8

    SciTech Connect

    Grob, P.M.; David, E.; Warren, T.C.; DeLeon, R.P.; Farina, P.R.; Homon, C.A. )

    1990-05-15

    Monocyte-derived neutrophil chemotactic factor/interleukin-8 (MDNCF/IL-8) is an 8,000-dalton protein produced by monocytes which exhibits activity as a chemoattractant for neutrophils with maximal activity achieved at a concentration of 50 ng/ml. This polypeptide has been iodinated by chloramine-T methodology (350 Ci/mM), and specific receptors for MDNCF/IL-8 have been detected on human neutrophils, U937 cells, THP-1 cells, and dimethyl sulfoxide-differentiated HL-60 cells. The binding of MDNCF/IL-8 to human neutrophils is not inhibited by interleukin-1 alpha, tumor necrosis factor-alpha, insulin, or epidermal growth factor. In addition, chemoattractants such as C5a, fMet-Leu-Phe, leukotriene B4, and platelet-activating factor fail to inhibit binding, suggesting that MDNCF/IL-8 utilizes a unique receptor. The receptor for MDNCF/IL-8 is apparently glycosylated since ligand binding is inhibited by the presence of wheat germ agglutinin, a lectin with a binding specificity for N-acetylglucosamine and neuraminic acid. Steady state binding experiments indicate Kd values of 4 and 0.5 nM and receptor numbers of 75,000 and 7,400 for human neutrophils and differentiated HL-60 cells, respectively. 125I-MDNCF/IL-8 bound to human neutrophils is rapidly internalized and subsequently released from cells as trichloroacetic acid-soluble radioactivity. Affinity labeling experiments suggest that the human neutrophil MDNCF/IL-8 receptor exhibits a mass of approximately 58,000 daltons.

  12. Human monocyte killing of Staphylococcus aureus: modulation by agonists of cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-monophosphate.

    PubMed Central

    O'Dorisio, M S; Vandenbark, G R; LoBuglio, A F

    1979-01-01

    This study was designed to test whether cyclic nucleotides play a role in the regulation of bacterial killing by human monocytes. Agents were tested for their ability to activate monocyte adenylate or guanylate cyclase in cell-free preparations, to increase cyclic adenosine 3',5'-monophosphate (cAMP) or cyclic guanosine 3',5'-monophosphate (cGMP) in intact human monocytes, and to modulate monocyte-induced killing of Staphylococcus aureus in vitro. Prostaglandin E1 and cholera toxin activated monocyte adenylate cyclase and inhibited monocyte killing of S. aureus. An adenylate cyclase inhibitor, RMI 12330A, reversed the prostaglandin E1-mediated inhibition of bacterial killing, thus implicating cAMP as the intracellular mediator of this inhibition. In contrast, monocyte cGMP levels were increased 5- and 17-fold by 5-hydroxytryptamine and N-methyl-N' -nitro-N-nitrosoguanidine, respectively, but neither agent was effective in modulating monocyte bactericidal activity. Thus, modulation of bactericidal activity in human monocytes did not conform to the yin/yang theory of opposing actions by cAMP and cGMP, for although monocyte-mediated killing of S. aureus was inhibited by cAMP agonists, it was not enhanced by cGMP agonists. PMID:44704

  13. Functional and Phenotypic Characteristics of Alternative Activation Induced in Human Monocytes by Interleukin-4 or the Parasitic Nematode Brugia malayi ▿ †

    PubMed Central

    Semnani, Roshanak Tolouei; Mahapatra, Lily; Moore, Vanessa; Sanprasert, Vivornpun; Nutman, Thomas B.

    2011-01-01

    Human monocytes from patients with patent filarial infections are studded with filarial antigen and express markers associated with alternative activation of macrophages (MΦ). To explore the role of filaria-derived parasite antigen in differentiation of human monocytes, cells were exposed to microfilariae (mf) of Brugia malayi, and their phenotypic and functional characteristics were compared with those of monocytes exposed to factors known to generate either alternatively (interleukin-4 [IL-4]) or classically (macrophage colony-stimulating factor [MCSF]) activated MΦ. IL-4 upregulated mRNA expression of CCL13, CCL15, CCL17, CCL18, CCL22, CLEC10A, MRC1, CADH1, CD274, and CD273 associated with alternative activation of MΦ but not arginase 1. IL-4-cultured monocytes had a diminished ability to promote proliferation of both CD4+ and CD8+ T cells compared to that of unexposed monocytes. Similar to results with IL-4, exposure of monocytes to live mf induced upregulation of CCL15, CCL17, CCL18, CCL22, CD274, and CD273 and downregulation of Toll-like receptor 3 (TLR3), TLR5, and TLR7. In contrast to results with MCSF-cultured monocytes, exposure of monocytes to mf resulted in significant inhibition of the phagocytic ability of these cells to the same degree as that seen with IL-4. Our data suggest that short exposure of human monocytes to IL-4 induces a phenotypic characteristic of alternative activation and that secreted filarial products skew monocytes similarly. PMID:21788379

  14. In vitro studies of human monocyte migration across endothelium in response to leukotriene B4 and f-Met-Leu-Phe.

    PubMed Central

    Migliorisi, G.; Folkes, E.; Pawlowski, N.; Cramer, E. B.

    1987-01-01

    Relatively little is known about monocyte emigration from the vasculature or about the factors that regulate this process. In this study, a human in vitro model of a blood vessel wall was used for examination of monocyte transendothelial migration. Umbilical vein endothelial cells were grown to confluency on amnion connective tissue, and human monocytes were stimulated to cross the monolayer in response to the chemoattractants leukotriene B4 or f-Met-Leu-Phe. The pattern and time course of monocyte migration were similar for the two chemotactic factors. In both cases, approximately 40-50% of the adherent monocytes extended single or multiple pseudopods into the apical endothelial surface. This indenting behavior was also observed in the absence of chemotactic factors. It was not affected by the medium (M199 or Gey's) or method of monocyte isolation. Neutrophils also displayed this behavior, but only about half as many neutrophils as monocytes indented the endothelial surface. The integrity of the endothelium remained intact as the monocytes traversed the monolayer. When the monocytes reached the basal surface of the endothelium, they frequently wedged themselves between the basal surface of the endothelium and its basal lamina. The monocytes then invaded the basal lamina and accumulated in the connective tissue. In response to both f-Met-Leu-Phe and leukotriene B4, monocyte migration across the endothelium began as early as 10 minutes. The average rate of accumulation in the connective tissue peaked at 30 minutes; and by 60 minutes, 25-35% of the monocytes had traversed the monolayer. Approximately two to three times as many monocytes traversed the endothelium under conditions of chemotaxis as under conditions of chemokinesis or random migration. These studies provide the basis for understanding the process of monocyte migration out of the bloodstream and lay the foundation for the study of their differentiation into macrophages in the connective tissue. Images

  15. Induced expression of the new cytokine, activin A, in human monocytes: inhibition by glucocorticoids and retinoic acid.

    PubMed Central

    Yu, J; Shao, L E; Frigon, N L; Lofgren, J; Schwall, R

    1996-01-01

    The capacity of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), glucocorticoids or all-trans-retinoic acid to modulate production of activin A by human monocytes was studied. It was shown that GM-CSF stimulated monocytes to accumulate activin A RNA after as few as 4 hr of incubation, reaching a peak of stimulation at approximately 16 hr of incubation. The activin A transcripts accumulated in the monocytes after stimulation with only 5 U/ml of GM-CSF and reached a maximum plateau level of expression between 25 and 50 U/ml of GM-CSF. Biologically active activin A molecules were detected in the conditioned media by a bioassay, performed both in the absence and presence of a neutralizing antiserum for activin A. Accumulation of bioactive activin A in conditioned medium of monocyte cultures was detected after 24 hr of incubation with GM-CSF and high levels of activin A were maintained for 72 hr. The production of the dimeric beta A beta A in these monocytes was further confirmed by sandwich enzyme-linked immunosorbent assay (ELISA) specific for activin A. In contrast to the stimulatory effect of GM-CSF, hydrocortisone, dexamethasone or all-trans-retinoic acid at 1 x 10(-7) to 1 x 10(-5) M inhibited the constitutive expression of activin A and greatly suppressed the GM-CSF-stimulated production. Thus, the expression of activin A is modulated in monocytes by different agents. These observations may imply new roles for activin A at sites of inflammation where monocytes accumulate. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8774352

  16. Patterns of Transcriptional Response to 1,25-Dihydroxyvitamin D3 and Bacterial Lipopolysaccharide in Primary Human Monocytes.

    PubMed

    Kariuki, Silvia N; Blischak, John D; Nakagome, Shigeki; Witonsky, David B; Di Rienzo, Anna

    2016-01-01

    The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D), plays an important immunomodulatory role, regulating transcription of genes in the innate and adaptive immune system. The present study examines patterns of transcriptome-wide response to 1,25D, and the bacterial lipopolysaccharide (LPS) in primary human monocytes, to elucidate pathways underlying the effects of 1,25D on the immune system. Monocytes obtained from healthy individuals of African-American and European-American ancestry were treated with 1,25D, LPS, or both, simultaneously. The addition of 1,25D during stimulation with LPS induced significant upregulation of genes in the antimicrobial and autophagy pathways, and downregulation of proinflammatory response genes compared to LPS treatment alone. A joint Bayesian analysis enabled clustering of genes into patterns of shared transcriptional response across treatments. The biological pathways enriched within these expression patterns highlighted several mechanisms through which 1,25D could exert its immunomodulatory role. Pathways such as mTOR signaling, EIF2 signaling, IL-8 signaling, and Tec Kinase signaling were enriched among genes with opposite transcriptional responses to 1,25D and LPS, respectively, highlighting the important roles of these pathways in mediating the immunomodulatory activity of 1,25D. Furthermore, a subset of genes with evidence of interethnic differences in transcriptional response was also identified, suggesting that in addition to the well-established interethnic variation in circulating levels of vitamin D, the intensity of transcriptional response to 1,25D and LPS also varies between ethnic groups. We propose that dysregulation of the pathways identified in this study could contribute to immune-mediated disease risk. PMID:26976439

  17. Patterns of Transcriptional Response to 1,25-Dihydroxyvitamin D3 and Bacterial Lipopolysaccharide in Primary Human Monocytes

    PubMed Central

    Kariuki, Silvia N.; Blischak, John D.; Nakagome, Shigeki; Witonsky, David B.; Di Rienzo, Anna

    2016-01-01

    The active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D), plays an important immunomodulatory role, regulating transcription of genes in the innate and adaptive immune system. The present study examines patterns of transcriptome-wide response to 1,25D, and the bacterial lipopolysaccharide (LPS) in primary human monocytes, to elucidate pathways underlying the effects of 1,25D on the immune system. Monocytes obtained from healthy individuals of African-American and European-American ancestry were treated with 1,25D, LPS, or both, simultaneously. The addition of 1,25D during stimulation with LPS induced significant upregulation of genes in the antimicrobial and autophagy pathways, and downregulation of proinflammatory response genes compared to LPS treatment alone. A joint Bayesian analysis enabled clustering of genes into patterns of shared transcriptional response across treatments. The biological pathways enriched within these expression patterns highlighted several mechanisms through which 1,25D could exert its immunomodulatory role. Pathways such as mTOR signaling, EIF2 signaling, IL-8 signaling, and Tec Kinase signaling were enriched among genes with opposite transcriptional responses to 1,25D and LPS, respectively, highlighting the important roles of these pathways in mediating the immunomodulatory activity of 1,25D. Furthermore, a subset of genes with evidence of interethnic differences in transcriptional response was also identified, suggesting that in addition to the well-established interethnic variation in circulating levels of vitamin D, the intensity of transcriptional response to 1,25D and LPS also varies between ethnic groups. We propose that dysregulation of the pathways identified in this study could contribute to immune-mediated disease risk. PMID:26976439

  18. Structure of human monocyte chemoattractant protein 4 (MCP-4/CCL13)

    SciTech Connect

    Barinka, Cyril; Prahl, Adam; Lubkowski, Jacek

    2008-04-02

    Monocyte chemoattractant proteins (MCPs) belong to the CC chemokine family and are involved in many (patho)physiological processes characterized by mononuclear cell infiltration, including tissue remodeling, atherosclerosis and cancer metastasis. Here, the crystal structure of human monocyte chemoattractant protein 4 (MCP-4) refined at 1.70 {angstrom} resolution is reported with crystallographic values R = 0.180 and R{sub free} = 0.212. The overall MCP-4 fold reveals the typical tertiary features of the CC chemokine family. A central three-stranded antiparallel {beta}-sheet is C-terminally flanked by an overlaying {alpha}-helix, while the N-terminal part of the molecule forms an extended loop that is anchored to the rest of the molecule via two disulfide bridges, Cys11-Cys35 and Cys12-Cys51. The crystal packing suggests the existence of MCP-4 dimers with a dimerization interface similar to those previously reported for the X-ray structures of MCP-1 and MCP-2.

  19. Role of mycobacteria-induced monocyte/macrophage apoptosis in the pathogenesis of human tuberculosis.

    PubMed

    Bocchino, M; Galati, D; Sanduzzi, A; Colizzi, V; Brunetti, E; Mancino, G

    2005-04-01

    Apoptosis is a physiological programmed cell death process whose dysregulation plays an important role in different human infectious diseases. An increasing number of intracellular pathogens are known to induce target cell apoptosis, while some other parasites inhibit it. Unlike necrosis, apoptosis is a silent immunological event occurring without inflammation. Infection-induced target cell apoptosis may be a successful strategy to eliminate pathogens and assure host survival. Conversely, apoptosis inhibition could represent an adaptive mechanism for pathogen survival, while it may be beneficial for the host to initiate an effective immune response. The worldwide increase in tuberculosis has stimulated more research aimed at defining the interaction between Mycobacterium tuberculosis and the immune system. M. tuberculosis possesses sophisticated strategies to circumvent its fate within target monocytic cells. Apoptosis of alveolar macrophages and monocytes has been described as a consequence of M. tuberculosis infection. Moreover, the observation that mycobacterial lipoproteins activate macrophages through Toll-like receptor (TLR) 2 suggests that innate immune receptors contribute to defence against M. tuberculosis. There is evidence that TLR-induced apoptosis modulates inflammation and immune activation during M. tuberculosis infection. Finally, the role of apoptotic-infected cells as a source of microbial antigens for cross-priming of effector T-cells is also discussed. PMID:15830742

  20. Human peripheral blood monocytes display surface antigens recognized by monoclonal antinuclear antibodies

    SciTech Connect

    Holers, V.M.; Kotzin, B.L.

    1985-09-01

    The authors used monoclonal anti-nuclear autoantibodies and indirect immunofluorescence to examine normal human peripheral blood mononuclear leukocytes for the presence of cell surface nuclear antigens. Only one monoclonal anti-histone antibody (MH-2) was found to bind to freshly isolated PBL, staining approximately 10% of large cells. However, after cells were placed into culture for 16-24 h, a high percentage (up to 60%) of large-sized cells were recognized by an anti-DNA (BWD-1) and several different antihistone monoclonal antibodies (BWH-1, MH-1, and MH-2). These antibodies recognize separate antigenic determinants on chromatin and histones extracted from chromatin. The histone antigen-positive cells were viable, and the monoclonal antibodies could be shown to be binding to the cell surface and not to the nucleus. Using monoclonal antibodies specific for monocytes and T cells, and complement-mediated cytotoxicity, the cells bearing histone antigens were shown to be primarily monocytes. The appearance of histone and DNA antigen-positive cells was nearly completely inhibited by the addition of low concentrations of cycloheximide at initiation of the cultures. In contrast, little effect on the percentage of positive cells was detected if cells were exposed to high doses of gamma irradiation before culture. These data further support the existence of cell surface nuclear antigens on selected cell subsets, which may provide insight into the immunopathogenesis of systemic lupus erythematosus and related autoimmune diseases.

  1. IκBζ Regulates Human Monocyte Pro-Inflammatory Responses Induced by Streptococcus pneumoniae.

    PubMed

    Sundaram, Kruthika; Rahman, Mohd Akhlakur; Mitra, Srabani; Knoell, Daren L; Woodiga, Shireen A; King, Samantha J; Wewers, Mark D

    2016-01-01

    Pneumococcal lung infections represent a major cause of death worldwide. Single nucleotide polymorphisms (SNPs) in the NFKBIZ gene, encoding the transcription factor IκBζ, are associated with increased susceptibility to invasive pneumococcal disease. We hence analyzed how IκBζ might regulate inflammatory responses to pneumococcal infection. We first demonstrate that IκBζ is expressed in human blood monocytes but not in bronchial epithelial cells, in response to wild type pneumococcal strain D39. D39 transiently induced IκBζ in a dose dependent manner, with subsequent induction of downstream molecules involved in host defense. Of these molecules, IκBζ knockdown reduced the expression of IL-6 and GMCSF. Furthermore, IκBζ overexpression increased the activity of IL-6 and GMCSF promoters, supporting the knockdown findings. Pneumococci lacking either pneumolysin or capsule still induced IκBζ. While inhibition of TLR1/TLR2 blocked D39 induced IκBζ expression, TLR4 inhibition did not. Blockade of p38 MAP kinase and NFκB suppressed D39 induced IκBζ. Overall, our data demonstrates that IκBζ regulates monocyte inflammatory responses to Streptococcus pneumoniae by promoting the production of IL-6 and GMCSF. PMID:27597997

  2. Human Monocyte-Derived Osteoclasts Are Targeted by Staphylococcal Pore-Forming Toxins and Superantigens.

    PubMed

    Flammier, Sacha; Rasigade, Jean-Philippe; Badiou, Cédric; Henry, Thomas; Vandenesch, François; Laurent, Frédéric; Trouillet-Assant, Sophie

    2016-01-01

    Staphylococcus aureus is the leading cause of bone and joint infections (BJIs). Staphylococcal pathogenesis involves numerous virulence factors including secreted toxins such as pore-forming toxins (PFTs) and superantigens. The role of these toxins on BJI outcome is largely unknown. In particular, few studies have examined how osteoclasts, the bone-resorbing cells, respond to exposure to staphylococcal PFTs and superantigens. We investigated the direct impact of recombinant staphylococcal toxins on human primary mature monocyte-derived osteoclasts, in terms of cytotoxicity and cell activation with cell death and bone resorption assays, using macrophages of the corresponding donors as a reference. Monocyte-derived osteoclasts displayed similar toxin susceptibility profiles compared to macrophages. Specifically, we demonstrated that the Panton-Valentine leukocidin, known as one of the most powerful PFT which lyses myeloid cells after binding to the C5a receptor, was able to induce the death of osteoclasts. The archetypal superantigen TSST-1 was not cytotoxic but enhanced the bone resorption activity of osteoclasts, suggesting a novel mechanism by which superantigen-producing S. aureus can accelerate the destruction of bone tissue during BJI. Altogether, our data indicate that the diverse clinical presentations of BJIs could be related, at least partly, to the toxin profiles of S. aureus isolates involved in these severe infections. PMID:26934588

  3. Granzyme K synergistically potentiates LPS-induced cytokine responses in human monocytes.

    PubMed

    Wensink, Annette C; Kemp, Vera; Fermie, Job; García Laorden, M Isabel; van der Poll, Tom; Hack, C Erik; Bovenschen, Niels

    2014-04-22

    Granzymes are serine proteases released by cytotoxic lymphocytes to induce apoptosis in virus-infected cells and tumor cells. Evidence is emerging that granzymes also play a role in controlling inflammation. Granzyme serum levels are elevated in patients with autoimmune diseases and infections, including sepsis. However, the function of extracellular granzymes in inflammation largely remains unknown. Here, we show that granzyme K (GrK) binds to Gram-negative bacteria and their cell-wall component lipopolysaccharide (LPS). GrK synergistically enhances LPS-induced cytokine release in vitro from primary human monocytes and in vivo in a mouse model of LPS challenge. Intriguingly, these extracellular effects are independent of GrK catalytic activity. GrK disaggregates LPS from micelles and augments LPS-CD14 complex formation, thereby likely boosting monocyte activation by LPS. We conclude that extracellular GrK is an unexpected direct modulator of LPS-TLR4 signaling during the antimicrobial innate immune response. PMID:24711407

  4. Human Monocyte-Derived Osteoclasts Are Targeted by Staphylococcal Pore-Forming Toxins and Superantigens

    PubMed Central

    Flammier, Sacha; Rasigade, Jean-Philippe; Badiou, Cédric; Henry, Thomas; Vandenesch, François; Laurent, Frédéric; Trouillet-Assant, Sophie

    2016-01-01

    Staphylococcus aureus is the leading cause of bone and joint infections (BJIs). Staphylococcal pathogenesis involves numerous virulence factors including secreted toxins such as pore-forming toxins (PFTs) and superantigens. The role of these toxins on BJI outcome is largely unknown. In particular, few studies have examined how osteoclasts, the bone-resorbing cells, respond to exposure to staphylococcal PFTs and superantigens. We investigated the direct impact of recombinant staphylococcal toxins on human primary mature monocyte-derived osteoclasts, in terms of cytotoxicity and cell activation with cell death and bone resorption assays, using macrophages of the corresponding donors as a reference. Monocyte-derived osteoclasts displayed similar toxin susceptibility profiles compared to macrophages. Specifically, we demonstrated that the Panton-Valentine leukocidin, known as one of the most powerful PFT which lyses myeloid cells after binding to the C5a receptor, was able to induce the death of osteoclasts. The archetypal superantigen TSST-1 was not cytotoxic but enhanced the bone resorption activity of osteoclasts, suggesting a novel mechanism by which superantigen-producing S. aureus can accelerate the destruction of bone tissue during BJI. Altogether, our data indicate that the diverse clinical presentations of BJIs could be related, at least partly, to the toxin profiles of S. aureus isolates involved in these severe infections. PMID:26934588

  5. Signal transduction pathways leading to the production of IL-8 by human monocytes are differentially regulated by dexamethasone.

    PubMed Central

    Anttila, H S; Reitamo, S; Ceska, M; Hurme, M

    1992-01-01

    Previous studies have shown that IL-8 gene expression is enhanced by various stimuli, which induce different signal transduction pathways. A lipopolysaccharide (LPS)-induced pathway has been reported to be inhibited by glucocorticoids in monocytes. We have now examined the effect of dexamethasone on the LPS-induced and other signal transduction pathways leading to the production of IL-8 by human monocytes. Dexamethasone inhibited the production of IL-8 stimulated with a cyclic adenosine monophosphate analog or LPS. In contrast, dexamethasone had no significant effect on a phorbol ester (PMA)-stimulated IL-8 production. These results suggest that the signal transduction pathways leading to the production of IL-8 by human monocytes are differentially regulated by dexamethasone. PMID:1325308

  6. Granzyme B Expression is Enhanced in Human Monocytes by TLR8 Agonists and Contributes to ADCC1

    PubMed Central

    Elavazhagan, Saranya; Fatehchand, Kavin; Santhanam, Vikram; Fang, Huiqing; Ren, Li; Gautam, Shalini; Reader, Brenda; Mo, Xiaokui; Cheney, Carolyn; Briercheck, Edward; Vasilakos, John P.; Dietsch, Gregory N.; Hershberg, Robert M.; Caligiuri, Michael; Byrd, John C.; Butchar, Jonathan P.; Tridandapani, Susheela

    2015-01-01

    Fcγ receptors (FcγR) are critical mediators of monoclonal antibody cancer therapies, as they drive cytotoxic processes upon binding of effector cells to opsonized targets. Along with natural killer (NK) cells, monocytes are also known to destroy antibody-coated targets via antibody-dependent cellular cytotoxicity (ADCC). However, the precise mechanisms by which monocytes carry out this function have remained elusive. Here, we show that human monocytes produce the protease Granzyme B upon both FcγR and Toll-like Receptor (TLR) 8 activation. Treatment with TLR8 agonists elicited Granzyme B and also enhanced FcγR-mediated Granzyme B production in an additive fashion. Furthermore, monocyte-mediated ADCC against cetuximab-coated tumor targets was enhanced by TLR8 agonist treatment, and this enhancement of ADCC required Granzyme B. Hence, we have identified Granzyme B as an important mediator of FcγR function in human monocytes and have uncovered another mechanism by which TLR8 agonists may enhance FcγR-based therapies. PMID:25667415

  7. Oxygen-Loaded Nanodroplets Effectively Abrogate Hypoxia Dysregulating Effects on Secretion of MMP-9 and TIMP-1 by Human Monocytes

    PubMed Central

    Gulino, Giulia Rossana; Magnetto, Chiara; Khadjavi, Amina; Panariti, Alice; Rivolta, Ilaria; Soster, Marco; Argenziano, Monica; Cavalli, Roberta; Giribaldi, Giuliana; Guiot, Caterina; Prato, Mauro

    2015-01-01

    Monocytes play a key role in the inflammatory stage of the healing process. To allow monocyte migration to injured tissues, the balances between secreted matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) must be finely modulated. However, a reduction of blood supply and local oxygen tension can modify the phenotype of immune cells. Intriguingly, hypoxia might be targeted by new effective oxygenating devices such as 2H,3H-decafluoropentane- (DFP-) based oxygen-loaded nanodroplets (OLNs). Here, hypoxia effects on gelatinase/TIMP release from human peripheral monocytes were investigated, and the therapeutic potential of dextran-shelled OLNs was evaluated. Normoxic monocytes constitutively released ~500 ng/mL MMP-9, ~1.3 ng/mL TIMP-1, and ~0.6 ng/mL TIMP-2 proteins. MMP-2 was not detected. After 24 hours, hypoxia significantly altered MMP-9/TIMP-1 balance by reducing MMP-9 and increasing TIMP-1, without affecting TIMP-2 secretion. Interestingly OLNs, not displaying toxicity to human monocytes after cell internalization, effectively counteracted hypoxia, restoring a normoxia-like MMP-9/TIMP-1 ratio. The action of OLNs was specifically dependent on time-sustained oxygen diffusion up to 24 h from their DFP-based core. Therefore, OLNs appear as innovative, nonconventional, cost-effective, and nontoxic therapeutic tools, to be potentially employed to restore the physiological invasive phenotype of immune cells in hypoxia-associated inflammation. PMID:25878404

  8. Differential Cytotoxicity but Augmented IFN-γ Secretion by NK Cells after Interaction with Monocytes from Humans, and Those from Wild Type and Myeloid-Specific COX-2 Knockout Mice

    PubMed Central

    Tseng, Han-Ching; Arasteh, Aida; Kaur, Kawaljit; Kozlowska, Anna; Topchyan, Paytsar; Jewett, Anahid

    2015-01-01

    The list of genes, which augment NK cell function when knocked out in neighboring cells is increasing, and may point to the fundamental function of NK cells targeting cells with diminished capability to differentiate optimally since NK cells are able to target less differentiated cells, and aid in their differentiation. In this paper, we aimed at understanding the effect of monocytes from targeted knockout of COX-2 in myeloid cells (Cox-2flox/flox;LysMCre/+) and from control littermates (Cox-2flox/flox;LysM+/+) on ex vivo function of NK cells. Furthermore, we compared the effect of monocytes treated with and without lipopolysaccharide (LPS) on NK cells from mice and humans. NK cells purified from Cox-2flox/flox;LysMCre/+ mice had heightened cytotoxic activity when compared to those obtained from control littermates. In addition, NK cells cultured with autologous Cox-2flox/flox;LysMCre/+ monocytes and DCs, mouse embryonic fibroblasts from global knockout COX-2, but not with knockout of COX-2 in T cells, had increased cytotoxic function as well as augmented IFN-γ secretion when compared to NK cells from control littermates cultured with monocytes. LPS inhibited NK cell cytotoxicity while increasing IFN-γ secretion when cultured in the presence of monocytes from either Cox-2flox/flox;LysMCre/+ or control littermates. In contrast to mice, NK cells from humans when cultured with monocytes lost cytotoxic function and gained ability to secrete large amounts of IFN-γ, a process, which we had previously coined as “split anergy.” Similar to mice, LPS potentiated the loss of human NK cell cytotoxicity while increasing IFN-γ secretion in the presence of monocytes. Greater loss of cytotoxicity and larger secretion of IFN-γ in NK cells induced by gene knockout cells may be important for the greater need of these cells for differentiation. PMID:26106386

  9. Activated Human Mast Cells Induce LOX-1-Specific Scavenger Receptor Expression in Human Monocyte-Derived Macrophages

    PubMed Central

    Alanne-Kinnunen, Mervi; Lappalainen, Jani; Öörni, Katariina; Kovanen, Petri T.

    2014-01-01

    Objective Activated mast cells in atherosclerotic lesions degranulate and release bioactive compounds capable of regulating atherogenesis. Here we examined the ability of activated human primary mast cells to regulate the expression of the major scavenger receptors in cultured human primary monocyte-derived macrophages (HMDMs). Results Components released by immunologically activated human primary mast cells induced a transient expression of lectin-like oxidized LDL receptor (LOX-1) mRNA in HMDMs, while the expression of two other scavenger receptors, MSR1 and CD36, remained unaffected. The LOX-1-inducing secretory components were identified as histamine, tumor necrosis factor alpha (TNF-α), and transforming growth factor beta (TGF-β1), which exhibited a synergistic effect on LOX-1 mRNA expression. Histamine induced a transient expression of LOX-1 protein. Mast cell –induced increase in LOX-1 expression was not associated with increased uptake of oxidized LDL by the macrophages. Conclusions Mast cell-derived histamine, TNF-α, and TGF-β1 act in concert to induce a transient increase in LOX-1 expression in human primary monocyte-derived macrophages. The LOX-1-inducing activity potentially endows mast cells a hitherto unrecognized role in the regulation of innate immune reactions in atherogenesis. PMID:25250731

  10. 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. PMID:25481443

  11. Serum amyloid A induces calcium mobilization and chemotaxis of human monocytes by activating a pertussis toxin-sensitive signaling pathway.

    PubMed

    Badolato, R; Johnston, J A; Wang, J M; McVicar, D; Xu, L L; Oppenheim, J J; Kelvin, D J

    1995-10-15

    We have previously reported that serum amyloid A (SAA) induces adhesion and chemotaxis of human monocytes and polymorphonuclear neutrophils, in vitro as well as in vivo. Since the mechanism of SAA signaling is unknown, we have investigated the possibility that SAA, like other chemoattractants such as the chemotactic peptide FMLP and chemokines, might induce migration of monocytes by G protein activation. We report here that preincubation of monocytes with pertussis toxin (PTx) inhibited SAA chemotaxis, while incubation with cholera toxin (CTx) did not. Staurosporine and H-7, both inhibitors of protein kinase C (PKC), significantly decreased rSAA-induced chemotaxis of monocytes, suggesting that PKC may be involved in the rSAA signaling pathway. Moreover, rSAA, at concentrations that were effective in chemoattracting monocytes, resulted in transient elevation of cytoplasmic calcium concentration ([Ca2+]i), and incubation of cells with PTx markedly inhibited the mobilization of Ca2+ in response to rSAA. This suggests that both chemotaxis and the rise in [Ca2+]i, are mediated by G proteins of the Gi class. The increase in [Ca2+]i, induced in monocytes by rSAA, was comparable to that elicited by FMLP, and was severalfold greater than that induced by optimal concentrations of chemokine beta-family members such as RANTES, MCAF/MCP-1, and MIP-1 alpha. The chemoattractants FMLP, RANTES, MIP-1 alpha, and MCAF/MCP-1, all failed to desensitize rSAA-induced Ca2+ influx and chemotaxis in monocytes. This suggests that SAA uses a distinct receptor that is coupled to PTx-sensitive G proteins. PMID:7561109

  12. Sargaquinoic Acid Inhibits TNF-α-Induced NF-κB Signaling, Thereby Contributing to Decreased Monocyte Adhesion to Human Umbilical Vein Endothelial Cells (HUVECs).

    PubMed

    Gwon, Wi-Gyeong; Lee, Bonggi; Joung, Eun-Ji; Choi, Min-Woo; Yoon, Nayoung; Shin, Taisun; Oh, Chul-Woong; Kim, Hyeung-Rak

    2015-10-21

    Sargaquinoic acid (SQA) has been known for its antioxidant and anti-inflammatory properties. This study investigated the effects of SQA isolated from Sargassum serratifolium on the inhibition of tumor necrosis factor (TNF)-α-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). SQA decreased the expression of cell adhesion molecules such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 as well as chemotactic cytokines such as interleukin-8 and monocyte chemoattractant protein-1 in TNF-α-treated HUVECs. As a result, SQA prevented monocyte adhesion to TNF-α-induced adhesion. SQA also inhibited TNF-α-induced nuclear factor kappa B (NF-κB) translocation into the nucleus by preventing proteolytic degradation of inhibitor κB-α. Overall, SQA protects against TNF-α-induced vascular inflammation through inhibition of the NF-κB pathway in HUVECs. These data suggest that SQA may be used as a therapeutic agent for vascular inflammatory diseases such as atherosclerosis. PMID:26437568

  13. Tumor necrosis factor alpha gene expression in human monocytic THP-1 cells exposed to beryllium.

    PubMed

    Galbraith, G M; Pandey, J P; Schmidt, M G; Arnaud, P; Goust, J M

    1996-01-01

    Chronic beryllium disease, which results from occupational exposure to particulate beryllium, is characterized by the development of lung granulomas and progressive pulmonary fibrosis. Increased production of proinflammatory cytokines (e.g., tumor necrosis factor alpha and interleukin-1 beta) by pulmonary alveolar macrophages occurs in many chronic fibrotic lung diseases and is thought to contribute to the disease process. The purpose of the present study was to investigate cytokine production by human monocytic cells exposed to beryllium in vitro. The results indicated that such cells respond to beryllium ions in the presence of fluoride by accumulation of messenger ribonucleic acid for both tumor necrosis factor alpha and interleukin-1 beta. These findings suggest that inhaled beryllium may directly stimulate the production of these cytokines by alveolar macrophages in vitro. PMID:8629860

  14. Ambroxol inhibits platelet-derived growth factor production in human monocytic cells.

    PubMed

    Utsugi, Mitsuyoshi; Dobashi, Kunio; Koga, Yasuhiko; Masubuchi, Ken; Shimizu, Yasuo; Endou, Katsuaki; Nakazawa, Tsugio; Mori, Masatomo

    2002-02-01

    Several growth factors, including platelet-derived growth factor (PDGF), have been implicated in the mechanism of lung and airway remodeling. We investigated the effect of ambroxol, trans-4-[(2-amino-3,5-dibromobenzyl) amino] cyclohexanol hydrochloride, on the lipopolysaccharide-induced PDGF production in human monocytic cells, THP-1. Ambroxol inhibited the lipopolysaccharide-induced PDGF-AB production via PDGF-A mRNA expression. Lipopolysaccharide activated p44/42 extracellular signal-regulated kinase (ERK), and ambroxol attenuated the lipopolysaccharide-induced p44/42 ERK activation. Furthermore, mitogen-activated protein kinase kinase (MEK)-1-specific inhibitor, 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one (PD 98059), blocked the lipopolysaccharide-induced p44/42 ERK activation and PDGF production. These findings indicate that ambroxol inhibits the lipopolysaccharide-induced PDGF production due to the suppression of p44/42 ERK activity. PMID:11834245

  15. Analyzing Illumina Gene Expression Microarray Data Obtained From Human Whole Blood Cell and Blood Monocyte Samples.

    PubMed

    Teumer, Alexander; Schurmann, Claudia; Schillert, Arne; Schramm, Katharina; Ziegler, Andreas; Prokisch, Holger

    2016-01-01

    Microarray profiling of gene expression is widely applied to studies in molecular biology and functional genomics. Experimental and technical variations make not only the statistical analysis of single studies but also meta-analyses of different studies very challenging. Here, we describe the analytical steps required to substantially reduce the variations of gene expression data without affecting true effect sizes. A software pipeline has been established using gene expression data from a total of 3358 whole blood cell and blood monocyte samples, all from three German population-based cohorts, measured on the Illumina HumanHT-12 v3 BeadChip array. In summary, adjustment for a few selected technical factors greatly improved reliability of gene expression analyses. Such adjustments are particularly required for meta-analyses of different studies. PMID:26614070

  16. 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

  17. Comparison of histamine release from human blood monocytes, lymphocytes, adenoidal and skin mast cells.

    PubMed

    Schmutzler, W; Bolsmann, K; Zwadlo-Klarwasser, G

    1995-01-01

    Monocytes and lymphocytes from human blood contain 0.043 +/- 0.007 and 0.053 +/- 0.014 pg histamine/cell, respectively, which can be released by a number of stimulants (A 23187, C5a, substance P, specific allergen). The release process takes 60-120 min to reach its end point, in contrast to tissue mast cells which complete the release within 1-3 min. Both, ketotifen (10(-7) - 10(-5) M) and disodium cromoglycate (10(-5) - 10(-3) M) inhibited histamine release dose dependently up to 40-45%, which might be particularly relevant during the later stages of acute allergic or pseudoallergic reactions. PMID:7542070

  18. Effect of pregnancy-specific β1-glycoprotein on indoleamine-2,3-dioxygenase activity in human monocytes.

    PubMed

    Zamorina, S A; Timganova, V P; Bochkova, M S; Khramtsov, P V; Raev, M B

    2016-07-01

    The role of heterogenic human pregnancy-specific glycoprotein (PSG), obtained by the authors' technology, in the regulation of the indoleamine-2,3-dioxygenase (IDO) activity in female blood monocytes has been studied in vitro. PSG stimulated IDO activity under the conditions of induction of the monocytes by interferon-γ. Upon the induction of cell proliferation by lipopolysaccharides, the stimulating effect was obtained only with 10 μg/mL of PSG. Enhanced IDO activity is probably a factor of peripheral immunological tolerance and antimicrobial protection against intracellular infections in the gestation period. PMID:27595833

  19. [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. PMID:27451498

  20. Measles virus infection enhances IL-1 beta but reduces tumor necrosis factor-alpha expression in human monocytes.

    PubMed

    Leopardi, R; Vainionpää, R; Hurme, M; Siljander, P; Salmi, A A

    1992-10-01

    Monocytes may play a role in the immunologic abnormalities caused by measles. The effect of measles virus (MV) infection on peripheral blood monocyte functions is poorly known. We report that MV-infected PBM have an altered pattern of IL-1 beta and TNF-alpha production in response to stimulation with LPS and PMA in vitro. MV-infected peripheral blood monocytes produced higher amounts of IL-1 beta, whereas the production of TNF-alpha was reduced. The same effect was observed in the human monocytic cell line THP-1, which was used for RNA analysis. An increased steady-state level of IL-1 beta mRNA was observed in MV-infected cells, and the level of TNF-alpha mRNA was reduced. However, both IL-1 beta and TNF-alpha had about 50% increased transcription rate. Analysis of the mRNA stability after transcriptional block by actinomycin D showed that the TNF-alpha mRNA had a reduced half-life in MV-infected cells (about 30 vs 80 min in uninfected cells), whereas IL-1 beta mRNA stability was similar in uninfected and MV-infected cells. These results indicate that MV infection disturbs the immunoregulatory network by interfering with the monocyte functions. PMID:1527385

  1. Flagella from Five Cronobacter Species Induce Pro-Inflammatory Cytokines in Macrophage Derivatives from Human Monocytes

    PubMed Central

    Cruz-Córdova, Ariadnna; Rocha-Ramírez, Luz M.; Ochoa, Sara A.; Gónzalez-Pedrajo, Bertha; Espinosa, Norma; Eslava, Carlos; Hernández-Chiñas, Ulises; Mendoza-Hernández, Guillermo; Rodríguez-Leviz, Alejandra; Valencia-Mayoral, Pedro; Sadowinski-Pine, Stanislaw; Hernández-Castro, Rigoberto; Estrada-García, Iris; Muñoz-Hernández, Onofre; Rosas, Irma; Xicohtencatl-Cortes, Juan

    2012-01-01

    Cronobacter spp. are opportunistic pathogens linked to lie-threatening infections in neonates and contaminated powdered infant formula that has been epidemiologically associated with these cases. Clinical symptoms of Cronobacter include necrotizing enterocolitis, bacteremia, and meningitis. Flagella from C. sakazakii are involved in biofilm formation and its adhesion to epithelial cells. We investigated the role of flagella from C. sakazakii ST1 and ST4, C. malonaticus, C. muytjensii, C. turicensis and C. dublinensis during the activation of cytokines (IL-8, TNF-α, and IL-10) in macrophage derivatives from human monocytes, which has not been extensively studied. The production and identity of flagella from the five Cronobacter species were visualized and recognized with anti-flagella antibodies by immunogold labeling through transmission electron microscopy. Purified flagella were dissociated into monomers in 12% SDS-PAGE Coomassie blue-stained gels showing a band of ∼28 kDa and, in addition, mass spectrometry revealed the presence of several peptides that correspond to flagellin. Flagella (100 ng) induced the release of IL-8 (3314–6025 pg/ml), TNF-α (39–359 pg/ml), and IL-10 (2–96 pg/ml), in macrophage isolates from human monocytes and similar results were obtained when flagella were dissociated into monomers. Inhibition assays using three dilutions of anti-flagella antibodies (1∶10, 1∶100, and 1∶200) suppressed the secretion of IL-8, TNF-α, and IL-10 between 95–100% using 100 ng of protein. A transfection assay using 293-hTLR5 cells showed IL-8 release of 197 pg/ml and suppression in the secretion of IL-8 when anti-hTLR5-IgA antibodies were used at different concentrations. These observations suggest that flagella and flagellin are involved in an inflammatory response dependent on TLR5 recognition, which could contribute to the pathogenesis of the bacteria. PMID:23284883

  2. Involvement of p38 MAPK in haemozoin-dependent MMP-9 enhancement in human monocytes.

    PubMed

    Khadjavi, Amina; Valente, Elena; Giribaldi, Giuliana; Prato, Mauro

    2014-01-01

    The lipid moiety of natural haemozoin (nHZ, malarial pigment) was previously shown to enhance expression and release of human monocyte matrix metalloproteinase-9 (MMP-9), and a major role for 15-(S,R)-hydroxy-6,8,11,13-eicosatetraenoic acid (15-HETE), a nHZ lipoperoxidation product, was proposed. Here, the underlying mechanisms were investigated, focusing on the involvement of mitogen-activated protein kinases (MAPKs). Results showed that nHZ promoted either early or late p38 MAPK phosphorylation; however, nHZ did not modify basal phosphorylation/expression ratios of extracellular signal-regulated kinase-1/2 and c-jun N-terminal kinase-1/2. 15-HETE mimicked nHZ effects on p38 MAPK, whereas lipid-free synthetic (s)HZ and delipidized (d)HZ did not. Consistently, both nHZ and 15-HETE also promoted phosphorylation of MAPK-activated protein kinase-2, a known p38 MAPK substrate; such an effect was abolished by SB203580, a synthetic p38 MAPK inhibitor. SB203580 also abrogated nHZ-dependent and 15-HETE-dependent enhancement of MMP-9 mRNA and protein (latent and activated forms) levels in cell lysates and supernatants. Collectively, these data suggest that in human monocytes, nHZ and 15-HETE upregulate MMP-9 expression and secretion through activation of p38 MAPK pathway. The present work provides new evidence on mechanisms underlying MMP-9 deregulation in malaria, which might be helpful to design new specific drugs for adjuvant therapy in complicated malaria. PMID:23468369

  3. Functional characterisation of human pulmonary monocyte-like cells in lipopolysaccharide-mediated acute lung inflammation

    PubMed Central

    2014-01-01

    Background We have previously reported the presence of novel subpopulations of pulmonary monocyte-like cells (PMLC) in the human lung; resident PMLC (rPMLC, HLA-DR+CD14++CD16+cells) and inducible PMLC (iPMLC, HLA-DR+CD14++CD16- cells). iPMLC are significantly increased in bronchoalveolar lavage (BAL) fluid following inhalation of lipopolysaccharide (LPS). We have carried out the first functional evaluation of PMLC subpopulations in the inflamed lung, following the isolation of these cells, and other lineages, from BAL fluid using novel and complex protocols. Methods iPMLC, rPMLC, alveolar macrophages (AM), neutrophils, and regulatory T cells were quantified in BAL fluid of healthy subjects at 9 hours post-LPS inhalation (n = 15). Cell surface antigen expression by iPMLC, rPMLC and AM and the ability of each lineage to proliferate and to undergo phagocytosis were investigated using flow cytometry. Basal cytokine production by iPMLC compared to AM following their isolation from BAL fluid and the responsiveness of both cell types following in vitro treatment with the synthetic corticosteroid dexamethasone were assessed. Results rPMLC have a significantly increased expression of mature macrophage markers and of the proliferation antigen Ki67, compared to iPMLC. Our cytokine data revealed a pro-inflammatory, corticosteroid-resistant phenotype of iPMLC in this model. Conclusions These data emphasise the presence of functionally distinct subpopulations of the monocyte/macrophage lineage in the human lung in experimental acute lung inflammation. PMID:24684897

  4. Exposure to Bacillus anthracis Capsule Results in Suppression of Human Monocyte-Derived Dendritic Cells

    PubMed Central

    Chabot, Donald J.; Bozue, Joel A.; Tobery, Steven A.; West, Michael W.; Moody, Krishna; Yang, De; Oppenheim, Joost J.

    2014-01-01

    The antiphagocytic capsule of Bacillus anthracis is a major virulence factor. We hypothesized that it may also mediate virulence through inhibition of the host's immune responses. During an infection, the capsule exists attached to the bacterial surface but also free in the host tissues. We sought to examine the impact of free capsule by assessing its effects on human monocytes and immature dendritic cells (iDCs). Human monocytes were differentiated into iDCs by interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) over 7 days in the presence of capsule derived from wild-type encapsulated B. anthracis Ames (WT) or a control preparation from an isogenic B. anthracis Ames strain that produces only 2% of the capsule of the WT (capA mutant). WT capsule consistently induced release of IL-8 and IL-6 while the capA mutant control preparation elicited either no response or only a minimal release of IL-8. iDCs that were differentiated in the presence of WT capsule had increased side scatter (SSC), a measure of cellular complexity, when assessed by flow cytometry. iDCs differentiated in the presence of WT capsule also matured less well in response to subsequent B. anthracis peptidoglycan (Ba PGN) exposure, with reduced upregulation of the chemokine receptor CCR7, reduced CCR7-dependent chemotaxis, and reduced release of certain cytokines. Exposure of naive differentiated control iDCs to WT capsule did not alter cell surface marker expression but did elicit IL-8. These results indicate that free capsule may contribute to the pathogenesis of anthrax by suppressing the responses of immune cells and interfering with the maturation of iDCs. PMID:24891109

  5. Geranylated flavanone tomentodiplacone B inhibits proliferation of human monocytic leukaemia (THP-1) cells

    PubMed Central

    Kollár, Peter; Bárta, Tomáš; Závalová, Veronika; Šmejkal, Karel; Hampl, Aleš

    2011-01-01

    BACKGROUND AND PURPOSE Paulownia tomentosa is a rich source of geranylated flavanones, some of which we have previously shown to have cytotoxic activity. To identify members of this class of compounds with cytostatic effects, we assessed the effects of the geranylated flavanone tomentodiplacone B (TOM B) on cell cycle progression and cell cycle regulatory pathways of THP-1 human monocytic leukaemia cells. EXPERIMENTAL APPROACH Cell viability was measured by dye exclusion and proliferation by WST-1 assays; cell cycle was monitored by flow cytometry. Regulatory proteins were assessed by immunoprecipitation and kinase assays, and Western blotting. KEY RESULTS Tomentodiplacone B had no effect during the first 24 h of cell growth at concentrations between 1 and 2.5 µM, but inhibited cell growth in a dose-dependent manner at concentrations of 5 µM or higher. Growth inhibition during the first 24 h of exposure to TOM B was not accompanied by cytotoxicity as cells were accumulated in G1 phase dose-dependently. This G1 phase accumulation was associated with down-regulation of cyclin-dependent kinase 2 activity and also protein levels of cyclins E1 and A2. However, key stress-related molecules (γ-H2AX, p53 and p21) were not induced, suggesting that TOM B acts by directly inhibiting the cyclin-dependent kinase 2 signalling pathway rather than initiating DNA damage or cellular stress. CONCLUSIONS AND IMPLICATIONS Our study provides the first evidence that TOM B directly inhibits proliferation of human monocytic leukaemia cells, and thus is a potential anticancer agent, preventing leukaemia cells from progressing from G1 phase into DNA synthesis. PMID:21175584

  6. Neurotoxic factors released by stimulated human monocytes and THP-1 cells.

    PubMed

    Lee, Moonhee; Suk, Kyoungho; Kang, Yunhee; McGeer, Edith; McGeer, Patrick L

    2011-07-11

    Activated monocytes/macrophages are known to release toxic materials. Identification of these materials is important for developing more effective treatments for inflammatory disorders where self attack occurs. We stimulated human monocytes and THP-1 cells with LPS/IFNγ and measured the toxic effects of their conditioned media against differentiated human NT-2 cells. Their cytotoxicity, as measured by LDH release, was reduced by half when their conditioned media was passed through a 3kDa cutoff filter, indicating an equal division between high and low molecular weight materials. When the high molecular weight components tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 were removed from the conditioned medium by specific antibodies, the toxicity was reduced by 37-38%. When prostaglandin production was blocked by treatment with the COX inhibitors acetylsalicylic acid and ibuprofen, toxicity was reduced by 15-16%. When oxygen free radical production was blocked by the NADPH inhibitor diphenylene iodonium (DPI) the toxicity was reduced by 17-18%. Treatment with the nitric oxide scavenger carboxy-phenyl-tetramethylimidazolineoxyl-oxide, or the NOS inhibitor N(G)-monomethylene-l-arginine, attenuated the toxicity by about 20%. Removal of released glutamate by glutamate decarboxylase also attenuated the toxicity by 12-13%. In combination, these treatments reduced the toxicity by approximately 50% accounting for the low molecular weight component toxicity. About 10% of the overall toxicity, which was associated with the high molecular weight component, was not identified. Optimal antiinflammatory therapy may require combined suppression of these identified toxin-generating pathways as well as relatively minor pathways yet to be identified. PMID:21640980

  7. Comparing methods for ex vivo characterization of human monocyte phenotypes and in vitro responses.

    PubMed

    Johnston, Lisa; Harding, Scott A; La Flamme, Anne Camille

    2015-12-01

    Monocytes are key innate effector cells and their phenotype and function may be a useful biomarker of disease state or therapeutic response. However, for such an assay to be clinically feasible it needs to be simple and reproducible, which this study aimed to address. Peripheral blood mononuclear cells (PBMC)(2) isolated from whole blood using Histopaque-1077 or cell preparation tubes (CPT) showed no difference in the ex vivo monocyte activation marker expression or in vitro responses; however, a delayed isolation using CPT significantly altered ex vivo and in vitro phenotypes and responses. Furthermore, purification of monocytes using CD14(+) microbeads resulted in a loss of CD14(low)CD16(+) monocytes compared to PBMC samples. Thus, the use of CPT reduced complexity and time compared to Histopaque, and PBMC isolation allowed the analysis of all 3 major monocyte subsets. Finally, because the delayed isolation of PBMC from CPT significantly altered monocytes, time delays should be standardized. PMID:26256247

  8. Effect of a standardized liver and spleen fraction of peptides on the differentiation of human monocyte-derived macrophages.

    PubMed

    Spessotto, P; Bulla, R; Mittenzwei, H; Dri, P

    1994-06-01

    The effect of Factor AF2 (AF2), a standardized fraction of peptides with a molecular weight of < 10,000 Dalton obtained from livers and spleens of newborn lambs, on the differentiation of human monocyte-derived macrophages was studied, in view of the central role played by these cells in inflammation and tumor cytotoxicity. The results show that the drug 1. increases the cell density of cultures, 2. favours the morphologic differentiation of monocytes into macrophages, and 3. increases the macrophages phagocytic capacity. The first two effects are observed when monocytes are cultured in 1% serum but not in 10% serum while the enhancement of phagocytic activity is detected at both serum concentrations. PMID:8053979

  9. Cyclooxygenase-1 and cyclooxygenase-2 selectivity of non-steroidal anti-inflammatory drugs: investigation using human peripheral monocytes.

    PubMed

    Kato, M; Nishida, S; Kitasato, H; Sakata, N; Kawai, S

    2001-12-01

    Since the pharmacological profiles of various non-steroidal anti-inflammatory drugs (NSAIDs) might depend on their differing selectivity for cyclooxygenase 1 (COX-1) and 2 (COX-2), we developed a new screening method using human peripheral monocytes. Monocytes from healthy volunteers were separated, and the cells were incubated with or without lipopolysaccharide (LPS). Monocytes without LPS stimulation exclusively expressed COX-1 on Western blotting analysis, whereas LPS stimulation induced COX-2 expression. Unstimulated monocytes (COX-1) and LPS-stimulated monocytes (COX-2) were then used to determinethe COX selectivity of various NSAIDs. The respective mean IC50 values for COX-1 and COX-2 IC50 (microM), and the COX-1/COX-2 ratio of each NSAID were as follows: celecoxib, 82, 6.8, 12; diclofenac, 0.076, 0.026, 2.9; etodolac, > 100, 53, > 1.9; ibuprofen, 12, 80, 0.15; indometacin, 0.0090, 0.31, 0.029; meloxicam, 37, 6.1, 6.1; 6-MNA (the active metabolite of nabumetone), 149, 230, 0.65; NS-398, 125, 5.6, 22; piroxicam, 47, 25, 1.9; rofecoxib, > 100, 25, > 4.0; S-2474, > 100, 8.9, > 11; SC-560, 0.0048, 1.4, 0.0034. The percentage inhibition of COX-1 activity at the IC50 of COX-2 also showed a wide variation among these NSAIDs. The bioassay system using human monocytes to assess the inhibitory effects of various NSAIDs on COX-1 and COX-2 may become a clinically useful screening method. PMID:11804398

  10. Transmigration of polymorphnuclear neutrophils and monocytes through the human blood-cerebrospinal fluid barrier after bacterial infection in vitro

    PubMed Central

    2013-01-01

    Background Bacterial invasion through the blood-cerebrospinal fluid barrier (BCSFB) during bacterial meningitis causes secretion of proinflammatory cytokines/chemokines followed by the recruitment of leukocytes into the CNS. In this study, we analyzed the cellular and molecular mechanisms of polymorphonuclear neutrophil (PMN) and monocyte transepithelial transmigration (TM) across the BCSFB after bacterial infection. Methods Using an inverted transwell filter system of human choroid plexus papilloma cells (HIBCPP), we studied leukocyte TM rates, the migration route by immunofluorescence, transmission electron microscopy and focused ion beam/scanning electron microscopy, the secretion of cytokines/chemokines by cytokine bead array and posttranslational modification of the signal regulatory protein (SIRP) α via western blot. Results PMNs showed a significantly increased TM across HIBCPP after infection with wild-type Neisseria meningitidis (MC58). In contrast, a significantly decreased monocyte transmigration rate after bacterial infection of HIBCPP could be observed. Interestingly, in co-culture experiments with PMNs and monocytes, TM of monocytes was significantly enhanced. Analysis of paracellular permeability and transepithelial electrical resistance confirmed an intact barrier function during leukocyte TM. With the help of the different imaging techniques we could provide evidence for para- as well as for transcellular migrating leukocytes. Further analysis of secreted cytokines/chemokines showed a distinct pattern after stimulation and transmigration of PMNs and monocytes. Moreover, the transmembrane glycoprotein SIRPα was deglycosylated in monocytes, but not in PMNs, after bacterial infection. Conclusions Our findings demonstrate that PMNs and monoctyes differentially migrate in a human BCSFB model after bacterial infection. Cytokines and chemokines as well as transmembrane proteins such as SIRPα may be involved in this process. PMID:23448224