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Human Blood Monocytes (human + blood_monocyte)

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Medical Sciences	50%

Selected Abstracts

Moderate Alcohol Intake in Humans Attenuates Monocyte Inflammatory Responses: Inhibition of Nuclear Regulatory Factor Kappa B and Induction of Interleukin 10

ALCOHOLISM, Issue 1 2006
Pranoti Mandrekar
Background: In contrast to the deleterious effects of chronic excessive alcohol consumption on the liver and cardiovascular system, modest alcohol intake, such as 1 to 2 drinks per day, has benefits on cardiovascular mortality. Little is known about the length of time or the amounts of alcohol consumed that may cause alterations in inflammatory cells such as monocytes that are crucial to atherosclerotic vascular disease. Here, we determine in vivo effects of acute alcohol consumption on inflammatory cytokine production and nuclear regulatory factor ,B (NF- ,B) binding in human monocytes. Methods: Human blood monocytes were isolated by plastic adherence before and after acute alcohol consumption (2 ml vodka/kg body weight). Lipopolysaccharide (LPS)- and superantigen-induced tumor necrosis factor , (TNF ,), interleukin (IL)-1,, and IL-10 production were then determined in monocytes by ELISA. Nuclear regulatory factor- ,B activity of monocytes before and after alcohol consumption was estimated by electromobility shift assay and promoter-driven reporter activity. I,B, was determined by Western blotting in the cytoplasmic extracts. Results: Eighteen hours after moderate alcohol consumption, we found a significant reduction in monocyte production of inflammatory mediators, TNF- , and IL-1,, in response to LPS or staphylococcal enterotoxin B stimulation. Acute alcohol consumption inhibited LPS-induced DNA binding of the p65/p50 NF- ,B in monocytes that regulates the expression of both the TNF- , and the IL-1, genes. Consistent with this, acute alcohol treatment (25 mM) significantly reduced LPS-induced activation of an NF- ,B-driven reporter gene suggesting inhibition of this proinflammatory signaling pathway. Further, LPS-induced I,B, degradation was not affected by acute alcohol consumption indicating an I,B, -independent mechanism, as observed earlier in the in vitro acute alcohol studies. In contrast, monocyte production of the anti-inflammatory cytokine, IL-10, was augmented by acute alcohol intake. Conclusions: Our findings suggest that acute alcohol consumption has dual anti-inflammatory effects that involve augmentation of IL-10 and attenuation of monocyte inflammatory responses involving inhibition of NF- ,B. These mechanisms may contribute to the beneficial effects of moderate alcohol use on atherosclerosis. [source]

Serum lipids regulate dendritic cell CD1 expression and function

IMMUNOLOGY, Issue 3 2008
David S. Leslie
Summary Dendritic cells (DCs) are highly potent antigen-presenting cells (APCs) and play a vital role in stimulating naïve T cells. Treatment of human blood monocytes with the cytokines granulocyte,macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 stimulates them to develop into immature dendritic cells (iDCs) in vitro. DCs generated by this pathway have a high capacity to prime and activate resting T cells and prominently express CD1 antigen-presenting molecules on the cell surface. The presence of human serum during the differentiation of iDCs from monocytes inhibits the expression of CD1a, CD1b and CD1c, but not CD1d. Correspondingly, T cells that are restricted by CD1c showed poor responses to DCs that were generated in the presence of human serum, while the responses of CD1d-restricted T cells were enhanced. We chemically fractionated human serum to isolate the bioactive factors that modulate surface expression of CD1 proteins during monocyte to DC differentiation. The human serum components that affected CD1 expression partitioned with polar organic soluble fractions. Lysophosphatidic acid and cardiolipin were identified as lipids present in normal human serum that potently modulate CD1 expression. Control of CD1 expression was mediated at the level of gene transcription and correlated with activation of the peroxisome proliferator-activated receptor (PPAR) nuclear hormone receptors. These findings indicate that the ability of human DCs to present lipid antigens to T cells through expression of CD1 molecules is sensitively regulated by lysophosphatidic acid and cardiolipin in serum, which are ligands that can activate PPAR transcription factors. [source]

Cytological properties of stromal cells derived from giant cell tumor of bone (GCTSC) which can induce osteoclast formation of human blood monocytes without cell to cell contact

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2005
Makoto Nishimura
Abstract When human blood monocytes were cocultured with stromal cells derived from human giant cell tumor of bone (GCTSC) and a Millipore filter (0.4 ,m) was interposed between monocytes and GCTSC, multinucleated giant cell formation of monocytes was induced. The multinucleated giant cells have characters as osteoclast-like cells, indicating that a soluble osteoclast-inducing factor(s) is secreted from GCTSC expressing RANK, RANKL/ODF/OPGL and TACE mRNA. Furthermore, OCIF/OPG inhibited GCTSC-induced osteoclastogenesis, showing that the RANK,RANKL system is involved in GCTSC-induced osteoclastogenesis and that soluble form of ODF/RANKL induces osteoclasts from monocytes. GCTSC expressed the cytokine mRNAs such as M-CSF, GM-CSF, IL-3, IL-4, IL-6, and IFN-, mRNAs. None of IL-1r,, IL-1,, IL-1,, IL-2, IL-4, IL-10, IL-18, TNF-,, GCSF and IFN-, could be detected in all culture media. A significant amount of IL-6 could be detected in the culture media of all GCTSC. IL-8 was found in the culture media of two GCTSC and two osteosarcoma-derived cells. M-CSF was detected in all culture media. GCTSC express CaSR, and stimulation of GCTSC with either extracellular Ca2+ or neomycin, agonist of CaSR, augumented the expression of RANKL. Some lines of GCTSC expressed alkaline phosphatase, osteocalcin and Cbfa1, suggesting that GCTSC are intimately related to osteoblastic lineage. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]