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Human Peripheral Blood Monocytes (human + peripheral_blood_monocyte)
Selected AbstractsAcute Alcohol Inhibits the Induction of Nuclear Regulatory Factor ,B Activation Through CD14/Toll-Like Receptor 4, Interleukin-1, and Tumor Necrosis Factor Receptors: A Common Mechanism Independent of Inhibitory ,B, Degradation?ALCOHOLISM, Issue 11 2002Pranoti Mandrekar Background Nuclear translocation and DNA binding of the nuclear factor ,B (NF-,B) is an early event in inflammatory cell activation in response to stimulation with bacterial components or cytokines. Cell activation via different receptors culminates in a common pathway leading to NF-,B activation and proinflammatory cytokine induction. We have previously shown that acute alcohol inhibits NF-,B activation by lipopolysaccharide (LPS) in human monocytes. Here we investigated whether acute alcohol treatment of human monocytes also inhibits NF-,B when induced through activation of the interleukin (IL)-1 or tumor necrosis factor (TNF) receptors. Methods Human peripheral blood monocytes were treated with LPS, TNF,, and IL-1, in the presence or absence of 25mM alcohol for 1 hr. NF-,B activation was determined by electrophoretic mobility shift assays using nuclear extracts. Inhibitory ,B, (I,B,) was estimated by Western blotting in cytoplasmic extracts. Chinese hamster ovary cells expressing human CD14 were treated with LPS in the presence or absence of alcohol to study NF-,B and I,B, regulation. Results Our results indicate that acute alcohol inhibits IL-1,- and TNF,-induced NF-,B activation. We further show in CD14/toll-like receptor 4,expressing Chinese hamster ovary cells the specificity of alcohol-mediated inhibition of NF-,B via the toll-like receptor 4/CD14 receptors. Inhibition of NF-,B by acute alcohol was concomitant with decreased levels of the I,B, molecule in the cytoplasm of LPS, IL-1, and TNF,-activated monocytes. Conclusions These data suggest a unique, I,B,-independent pathway for the inhibition of NF-,B activation by acute alcohol in monocytes. Universal inhibition of NF-,B by acute alcohol via these various receptor systems suggests a target for the effects of alcohol in the NF-,B activation cascade that is downstream from I,B, degradation. Further, these results demonstrate that acute alcohol is a potent inhibitor of NF-,B activation by mediators of early (LPS) or late (IL-1, TNF,) stages of inflammation in monocytes. [source] Targeted replacement of rodent CCR2 with the human orthologue CCR2B: A mouse model for in vivo analysis of human target-selective small molecule MCP-1 receptor antagonistsDRUG DEVELOPMENT RESEARCH, Issue 4 2002Haydn M. Prosser Abstract Rodent models for testing the efficacy of lead compounds are often invalidated by species selectivity of the compounds. The advent of mouse embryonic stem cell technology has allowed the development of genetically engineered mouse strains that incorporate a specific human gene in place of the orthologous mouse gene, a so-called knock-in mouse. This study describes the generation and validation of a mutant mouse line that expresses human CCR2B as a functional substitute for murine CCR2. The human CCR2B knock-in mice are viable and appear normal. In vitro assays indicate that the CCR2B knock-in is functionally expressed, giving a macrophage chemotactic profile in response to JE or MCP-1 that is similar to human peripheral blood monocytes rather than that of a murine macrophage cell line. In addition, the human selective CCR2B antagonist, SB-399721, was a more potent inhibitor of CCR2B knock-in macrophages in response to hMCP-1 than JE. The ability of the human CCR2B gene to functionally substitute for the mouse orthologue in vivo is demonstrated by a normal inflammatory response to intraperitoneal thioglycollate injection. Drug Dev. Res. 55:197,209, 2002. © 2002 Wiley-Liss, Inc. [source] TNF-, suppresses dendritic cell death and the production of reactive oxygen intermediates induced by plasma withdrawalEXPERIMENTAL DERMATOLOGY, Issue 5 2004Hong-Duck Um Abstract:, Mature dendritic cells (DCs) were generated by culturing human peripheral blood monocytes for 7 days and, then, treating them with a cytokine cocktail for 2 days. The viability of the mature DCs (Day 9) obtained was approximately 60,70%, and this gradually declined when they were recultured in X-VIVO 15 media containing 2% human plasma (40% viability after 3 days of reculture). DC death accelerated on withdrawing plasma from the culture (20% viability after 3 days). However, the addition of tumor necrosis factor-, (TNF-,) to the medium completely restored DC viability in the absence of plasma. Such a protective effect was not afforded by other cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1, (IL-1,), IL-4, IL-6 and prostaglandin E2 which are used for the maturation of DCs. These results indicate that TNF-, is specifically required to maintain the viability of mature DCs. The withdrawal of plasma rapidly (within 15 min) elevated cellular levels of reactive oxygen intermediates (ROIs), which have been proposed to regulate the ability of DCs to control inflammatory reactions. The possibility that ROIs act as mediators of DC death was eliminated by the observation that scavengers of ROIs, such as catalase, N -acetylcysteine, glutathione, failed to prolong DC life span in the absence of plasma. Interestingly, TNF-, was found to almost completely abolish the production of ROIs induced by plasma withdrawal. To summarize, our results suggest that TNF-, controls not only the inflammatory functions of DCs but also their survival. [source] Interleukin-6 Induction by Helicobacter pylori in Human Macrophages is Dependent on PhagocytosisHELICOBACTER, Issue 3 2006Stefan Odenbreit Abstract Background:, The colonization of the gastric mucosa with Helicobacter pylori is accompanied by elevated levels of proinflammatory cytokines, such as interleukin-1 (IL-1), IL-6, and IL-8. The aim of our study was to determine the mechanisms of IL-6 stimulation in phagocytes upon H. pylori infection. Materials and Methods:, We investigated the secretion of IL-6 by different professional phagocytes from murine and human origin, including granulocyte- and monocyte-like cells and macrophages derived from human peripheral blood monocytes (PBMCs). The influence of viability, phagocytosis, and the impact of different subcellular fractions of H. pylori bacteria were evaluated. Results:, IL-6 levels induced by H. pylori were low in cell lines derived from murine and human monocytes and in human granulocyte-like cells. By contrast, macrophages derived from human PBMCs were highly responsive to both H. pylori and Escherichia coli. IL-6 induction was blocked by inhibition of actin-dependent processes prior to infection with H. pylori, but not with E. coli or E. coli lipopolysaccharide (LPS). Using cell fractionation, the most activity was found in the H. pylori membrane. H. pylori LPS exhibited a 103 - to 104 -fold lower biologic activity than E. coli LPS, suggesting a minor role for toll-like receptor 4 (TLR4)-mediated signalling from the exterior. Conclusions:, From these data, we conclude that macrophages may be a major source of IL-6 in the gastric mucosa upon H. pylori infection. The IL-6 induction by H. pylori in these cells is a multifactorial process, which requires the uptake and presumably degradation of H. pylori bacteria. [source] Hericium erinaceum induces maturation of dendritic cells derived from human peripheral blood monocytesPHYTOTHERAPY RESEARCH, Issue 1 2010Sun Kyung Kim Abstract Hericium erinaceum, a medicinal mushroom, has long been used as a therapeutic due to its immuno-regulating potentials eliciting anticarcinogenic and antimicrobial efficacies. Since maturation of dendritic cells (DC) is an important process in the initiation and regulation of immune responses, the ability of water-soluble components from H. erinaceum (WEHE) to regulate DC maturation was investigated. Immature DC were prepared by differentiating human peripheral blood CD14-positive cells with GM-CSF and IL-4. DC were stimulated with WEHE at 2,20 µg/mL for 48 h and subjected to flow cytometric analysis to determine the expression of indicative maturation markers. The endocytic capacity of WEHE-stimulated DC was examined by a Dextran-FITC uptake assay. An enzyme-linked immunosorbent assay was performed to examine the secretion of TNF- , and IL-12p40. DC stimulated with WEHE showed representative features upon DC maturation: enhanced expression of CD80, CD83 and CD86, and both MHC class I and II molecules, decreased endocytic capacity of DC, increased expression of CD205, and decreased expression of CD206. However, interestingly, WEHE could not induce the production of TNF- , and IL-12p40, whereas lipopolysaccharide substantially increased the production of both cytokines. Collectively, these results suggest that H. erinaceum induces the maturation of human DC, which might reinforce the host innate immune system. Copyright © 2009 John Wiley & Sons, Ltd. [source] Effects of arsenobetaine, a major organic arsenic compound in seafood, on the maturation and functions of human peripheral blood monocytes, macrophages and dendritic cellsAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2004Takami Ohta Abstract We examine the in vitro immunotoxicity of synthetically pure arsenobetaine [AsBe; trimethyl (carboxymethyl) arsonium zwitterion], which is a major organic arsenic compound in seafood, on various human immune cells, such as peripheral blood monocytes, monocyte-derived macrophages and monocyte-derived dendritic cells (DCs). In particular, we examine the differentiation of monocytes into macrophages or DCs by comparing the effects of AsBe with those pentavalent inorganic arsenate. AsBe neither enhanced nor inhibited the differentiation of human monocytes into macrophages or DCs, and also did not affect their various immune functions. Furthermore, AsBe had no cytolethality in monocyte-derived macrophages or DCs even at a concentration of 5 mmol l,1. In contrast, inorganic arsenate showed strong cytolethality in these human immune cells in vitro at micromolar concentrations. These data indicate that the organic arsenic compound AsBe in seafood has no in vitro immunotoxicity in human immune cells. Copyright © 2004 John Wiley & Sons, Ltd. [source] Induction of the expression of profibrotic cytokines and growth factors in normal human peripheral blood monocytes by gadolinium contrast agentsARTHRITIS & RHEUMATISM, Issue 5 2009Peter J. Wermuth Objective Nephrogenic systemic fibrosis (NSF) is a severe fibrosing disorder occurring in patients with renal insufficiency. The majority of patients with this disorder have documented exposure to magnetic resonance imaging contrast agents containing Gd. The purpose of this study was to examine the effects of gadolinium diethylenetriaminepentaacetic acid bismethylamide (Gd[DTPA-BMA]; Omniscan) as compared with Gd-DTPA and GdCl3 on the expression and production of cytokines and growth factors by normal human peripheral blood monocytes in vitro and to examine whether conditioned media from Gd-exposed peripheral blood monocytes could induce a profibrotic phenotype in dermal fibroblasts. Methods Normal human peripheral blood monocytes isolated by Ficoll-Hypaque gradient centrifugation and plastic adherence were incubated with various concentrations of Gd[DTPA-BMA], Gd-DTPA, or GdCl3. Gene expression of interleukins 4, 6, and 13, interferon-,, tumor necrosis factor ,, transforming growth factor ,, connective tissue growth factor, and vascular endothelial growth factor were assessed by real-time polymerase chain reaction (PCR) analysis. Production and secretion of cytokines and growth factors by Gd compound,exposed monocytes was quantified by enzyme-linked immunosorbent assay proteome multiplex arrays. The effects of conditioned media from the Gd compound,exposed monocytes on the phenotype of normal human dermal fibroblasts were examined by real-time PCR and Western blotting. Results The 3 Gd-containing compounds stimulated the expression and production of numerous cytokines and growth factors by normal human peripheral blood monocytes. Conditioned media from these cells induced a profibrotic phenotype in normal human dermal fibroblasts. Conclusion The 3 Gd-containing compounds studied induce potent cellular responses in normal human peripheral blood monocytes, which may participate in the development of tissue fibrosis in NSF. [source] | ||||||||||