Search results for "Monocyte"
showing 10 items of 381 documents
Proteomic differentiation pattern in the U937 cell line
2011
The U937 cell line, originally established from a histiocytic lymphoma, has been widely used as a powerful in vitro model for haematological studies. These cells retain the immature cell phenotype and can be induced to differentiate by several factors, among which 12-O-tetradecanoyl-13-phorbol acetate (TPA). Fully differentiated cells acquire the adherent phenotype and exhibit various properties typical of macrophages. However, in spite of a great deal of research devoted to the U937 cellular model, the molecular basis of biological processes involved in the monocyte/macrophage differentiation remains unclear. The present study has been undertaken to contribute to this knowledge, in order t…
Biological properties of extracellular vesicles and their physiological functions
2015
The authors wish to thank Dr R Simpson and Dr D Taylor for critical reading of the manuscript and acknowledge the Horizon 2020 European Cooperation in Science and Technology programme and its support of our European Network on Microvesicles and Exosomes in Health & Disease (ME-HaD; BM1202 www.cost.eu/COST_Actions/bmbs/Actions/BM1202). In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive invest…
Soot-exposed mononuclear cells increase inflammatory cytokine mRNA expression and protein secretion in cocultured bronchial epithelial cells.
2000
<i>Background:</i> Soot particles are air pollutants capable of inducing airway and lung parenchymal injury. Mononuclear and bronchial epithelial cells are central to the maintenance of homeostasis and inflammation in the airways. <i>Objectives:</i> The aim of this study was to evaluate the contribution of mononuclear cells to the release of inflammatory mediators by bronchial epithelial cells. <i>Methods:</i> To model the in vivo situation, an in vitro system of cocultured blood monocytes and BEAS-2B cells was established in a transwell system. Blood monocytes were exposed to soot particles (FR 101) at concentrations of up to 100 μg/10<sup>6</su…
Production of reactive oxygen intermediates by human macrophages exposed to soot particles and asbestos fibers and increase in NF-kappa B p50/p105 mR…
1999
Alveolar macrophages (AM) play a decisive role in the immunologic defense system of the lung and in inflammatory pulmonary pathomechanisms. AM and blood monocytes (BM) were exposed to chrysotile B, soot FR 101, and Printex 90 (P 90). We evaluated the reactive oxygen intermediate (ROI) release of AM and BM after particle exposure. ROI release was measured by chemiluminescence. Thirty-minute exposure caused a significant (up to 2.5-fold) increase in ROI release of AM (100 micrograms/10(6) cells) compared with control experiments (p0.01). Identical exposure conditions for BM resulted in a similar reaction pattern (maximum 2.2-fold increase in ROI release; p0.05). After a 90-min particle exposu…
Lung-restricted activation of the alveolar macrophage/monocyte system in pulmonary sarcoidosis.
1992
An activation of T-cells that is restricted to the lung has been demonstrated in pulmonary sarcoidosis. The role of blood monocytes (MO) and alveolar macrophages (AM) in this concept of compartmentalized inflammation has not yet been evaluated. In order to elucidate this question, we measured the release of tumor necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) by peripheral blood mononuclear cells (PBMNC) and AM in 43 patients with sarcoidosis (32 with active, 11 with inactive disease) without therapy and correlated the spontaneous monokine release to parameters of the T-cell alveolitis and the course of the disease. TNF alpha as well as IL-1 were spontaneously released by AM of …
Theophylline suppresses the release of tumour necrosis factor-alpha by blood monocytes and alveolar macrophages.
1994
The purpose of this study was to evaluate the effect of theophylline on tumour necrosis factor-alpha (TNF-alpha) release by human blood monocytes (BMo), and rat BMo and alveolar macrophages (AM). BMo and AM were incubated in the absence or presence of theophylline, and the cell-free supernatants were harvested and tested for TNF-alpha activity by bioassay. Theophylline dose-dependently reduced TNF-alpha release by human BMo: significant inhibition was observed at 100 microns (41 +/- 5.9% of controls) and at 50 microns (59 +/- 4.8% of controls), while the inhibitory activity of theophylline at 10 microns (71 +/- 8.9% of controls) was not statistically significant. This activity was maximal a…
Identification and purification of human erythroid progenitor cells by monoclonal antibody to the transferrin receptor (T� 67)
1988
Anti-TU 67 is a murine monoclonal antibody that recognizes the transferrin receptor. With respect to hematopoietic cells TU 67 is expressed by human multipotent colony-forming cells (CFU-Mix), erythroid progenitor cells (BFU-E and CFU-E) and a fraction of granulocyte/monocyte colony forming cells, but is not expressed by mature hematopoietic cells including erythrocytes, platelets, lymphocytes, and peripheral blood myeloid cells. The TU 67-positive fraction of normal bone marrow, separated by fluorescence-activated cell sorting (FACS) or immune rosettes, contained 87% of the erythroid progenitor cells. Erythroid progenitor cells were enriched up to 50-fold by using a combination of monoclon…
Chronic lymphocytic leukemia nurse-like cells express hepatocyte growth factor receptor (c-MET) and indoleamine 2,3-dioxygenase and display features …
2014
Hepatocyte growth factor, produced by stromal and follicular dendritic cells, and present at high concentrations in the sera of patients with chronic lymphocytic leukemia, prolongs the survival of leukemic B cells by interacting with their receptor, c-MET. It is, however, unknown whether hepatocyte growth factor influences microenvironmental cells, such as nurse-like cells, which deliver survival signals to the leukemic clone. We evaluated the expression of c-MET on nurse-like cells and monocytes from patients with chronic lymphocytic leukemia and searched for phenotypic/functional features supposed to be influenced by the hepatocyte growth factor/c-MET interaction. c-MET is expressed at hi…
Osteopontin shapes immunosuppression in the metastatic niche.
2014
Abstract The matricellular protein osteopontin (OPN, Spp-1) is widely associated with cancer aggressiveness when produced by tumor cells, but its impact is uncertain when produced by leukocytes in the context of the tumor stroma. In a broad study using Spp1−/− mice along with gene silencing in tumor cells, we obtained evidence of distinct and common activities of OPN when produced by tumor or host cells in a spontaneously metastatic model of breast cancer. Different cellular localization of OPN is associated with its distinct activities, being mainly secreted in tumor cells while intracellular in myeloid cells. OPN produced by tumor cells supported their survival in the blood stream, wherea…
Looking for biological factors to predict the risk of active cytomegalovirus infection in non-immunosuppressed critically ill patients
2013
The identification of non-immunosuppressed critically ill patients most at risk for developing cytomegalovirus (CMV) reactivation is potentially of great clinical relevance. The current study was aimed at determining (i) whether single nucleotide polymorphisms in the genes coding for chemokine receptor 5 (CCR5), interleukin-10 IL-10), and monocyte chemoattractant protein-1 (MCP-1) have an impact on the incidence rate of active CMV infection, (ii) whether serum levels of CMV-specific IgGs are associated with the risk of CMV reactivation, and (iii) whether detection of CMV DNA in saliva precedes that in the lower respiratory tract or the blood compartment. A total of 36 out of 78 patients (46…