Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A hyperdynamic sepsis model was set up in seven adult baboons to evaluate neutrophil-activating peptide-1/interleukin (IL)-8 (NAP-1/IL-8), IL-1 beta, IL-6, tumor necrosis factor-alpha (TNF alpha), and IFN-gamma in plasma. By continuous intravenous administration of 10(10) cfu/kg live Escherichia coli over 8 h with additional infusion therapy (less than or equal to 50 ml/kg/h), endotoxin plasma levels of 2.7-22.3 ng/ml were observed. In plasma the kinetics of NAP-1/IL-8 and IL-6 were similar to those of IL-1 at the end of the experiment (8 h) (peak median values, 34, 4197, and 230 ng/ml, respectively). Differences were greatest for IL-6. Monocyte activation during sepsis was confirmed by elevated plasma neopterin levels (91-139 mumol/mmol of creatine). Granulocyte activation was evident from both incipient neutropenia and the massive release of neutrophil elastase into the plasma as measured by a new immunoassay (peak level, 374 ng/ml). Thus, in primate bacteremia, early TNF release is followed by a concomitant increase of NAP-1/IL-8 with plasma kinetics similar to those of IL-6 and IL-1 and accompanied by massive activation of neutrophils.
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PMID:Plasma neutrophil-activating peptide-1/interleukin-8 and neutrophil elastase in a primate bacteremia model. 190 12

Cells of the synovial microenvironment may recruit neutrophils (PMN) and lymphocytes into synovial fluid, as well as lymphocytes into the synovial tissues, of arthritic patients. We have investigated the production of the chemotactic cytokine IL-8 by using sera, synovial fluid, synovial tissue, and macrophages and fibroblasts isolated from synovial tissues from 75 arthritic patients. IL-8 levels were higher in synovial fluid from rheumatoid (RA) patients (mean +/- SE, 14.37 +/- 5.8 ng/ml), compared with synovial fluid from osteoarthritis patients (0.135 +/- 17 ng/ml) (p less than 0.05) or from patients with other arthritides (5.52 +/- 5.11 ng/ml). IL-8 from RA sera was 8.44 +/- 2.33 ng/ml, compared with nondetectable levels found in normal sera. IL-8 levels from RA sera and synovial fluid were strongly positively correlated (r = 0.96, p less than 0.05). Moreover, RA synovial fluid chemotactic activity for PMN in these fluids was inhibited 40 +/- 5% upon incubation with neutralizing polyclonal antibody to IL-8. Synovial tissue fibroblasts released only small amounts of constitutive IL-8 but could be induced to produce IL-8 by stimulation with either IL-1 beta, TNF-alpha, or LPS. In contrast, unlike normal PBMC or alveolar macrophages, macrophages isolated from RA synovial tissue constitutively expressed both IL-8 mRNA and antigenic IL-8. RA synovial macrophage IL-8 expression was not augmented by incubation with either LPS, TNF-alpha, or IL-1 beta. Immunohistochemical analysis of synovial tissue showed that a greater percentage of RA macrophages than osteoarthritis macrophages reacted with anti-IL-8. Whereas macrophages were the predominant cell for immunolocalization of IL-8, less than 5% of synovial tissue fibroblasts were positive for immunolocalized IL-8. These results suggest that macrophage-derived IL-8 may play an important role in the recruitment of PMN in synovial inflammation associated with RA.
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PMID:Synovial tissue macrophage as a source of the chemotactic cytokine IL-8. 191 55

The pulmonary fibroblast's (PF) unique location allows it to communicate in a bidirectional fashion between the vascular compartment and alveolar airspace, placing it in a strategic position for the elicitation of inflammatory leukocytes into the lung. In this study, we demonstrate that PF may contribute to pulmonary inflammation through the production of a potent neutrophil chemotactic factor, interleukin (IL)-8. PF-derived IL-8 expression was dependent upon stimulation by either tumor necrosis factor (TNF) or IL-1 but not lipopolysaccharide (LPS). Both TNF and IL-1 stimulation of PF resulted in a time- and dose-dependent expression of steady-state levels of mRNA, antigen, and specific chemotactic activity consistent with IL-8. Because it was apparent that cytokine networking may exist in the lung between alveolar macrophage (AM)-derived cytokines and the production of PF-derived IL-8, we next examined an in vitro model of cellular communication within the lung. We determined that LPS-stimulated AM-conditioned media induced significant levels of PF-derived IL-8 mRNA, which was inhibited by preincubation with specific neutralizing TNF and IL-1 beta antibodies. Furthermore, when AM were directly co-cultured with PF and stimulated with LPS, the kinetic analysis of PF-derived antigenic expression of IL-8 was shifted toward the right. This suggested that PF-derived IL-8 expression in co-culture was first dependent upon activation of the AM by LPS and subsequent elaboration of macrophage inflammatory mediators. These data provide evidence that cytokine networking between AM and PF may be operative in the lung, culminating in the generation of IL-8 and elicitation of inflammatory leukocytes.
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PMID:Pulmonary fibroblast expression of interleukin-8: a model for alveolar macrophage-derived cytokine networking. 193 Oct 78

Gelatinases (type IV collagenases) produced by normal peripheral blood leukocytes were studied by the use of a substrate conversion assay. When monocytes were stimulated with IL-1 beta discrete amounts of a 85-kDa gelatinase were detected. This type of gelatinase comigrated with a phorbol ester-inducible metalloproteinase from human tumor cells. The levels of induction of the monocytic enzyme after stimulation with IL-1, double-stranded RNA, LPS, and mitogens paralleled those of the secondary cytokine IL-6. When peripheral blood neutrophils were stimulated with IL-8 or PMA significant amounts of a 91-kDa neutrophil gelatinase were released, whereas with IL-1 beta no effect was observed. Both neutrophil and monocyte gelatinases cross-reacted in immunoprecipitation experiments with tumor cell-derived gelatinases. Further evidence for structural similarity between the IL-1-inducible monocytic (85 kDa) and the IL-8-regulated neutrophilic (91 kDa) gelatinases was obtained after purification of the proteins to homogeneity: both gelatinases possessed an identical amino terminal amino acid sequence and appeared as truncated forms of gelatinase from tumor cells. Synovial fluids of arthritic joints contained extremely high concentrations of the 91-kDa gelatinase. The concentrations of this type of gelatinase were correlated with the titers of the marker cytokine IL-6. The controlled production and activity of leukocyte-derived gelatinase may play an essential role in local proteolysis of the extracellular matrix and in leukocyte migration. In the arthritis patient this enzyme might contribute to the pathogenesis of joint destruction and might constitute a useful marker of disease status.
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PMID:Cytokine-mediated regulation of human leukocyte gelatinases and role in arthritis. 193 76

In the present study we demonstrate that human monocytes activated by lipopolysaccharides (LPS) were able to produce high levels of interleukin 10 (IL-10), previously designated cytokine synthesis inhibitory factor (CSIF), in a dose dependent fashion. IL-10 was detectable 7 h after activation of the monocytes and maximal levels of IL-10 production were observed after 24-48 h. These kinetics indicated that the production of IL-10 by human monocytes was relatively late as compared to the production of IL-1 alpha, IL-1 beta, IL-6, IL-8, tumor necrosis factor alpha (TNF alpha), and granulocyte colony-stimulating factor (G-CSF), which were all secreted at high levels 4-8 h after activation. The production of IL-10 by LPS activated monocytes was, similar to that of IL-1 alpha, IL-1 beta, IL-6, IL-8, TNF alpha, granulocyte-macrophage colony-stimulating factor (GM-CSF), and G-CSF, inhibited by IL-4. Furthermore we demonstrate here that IL-10, added to monocytes, activated by interferon gamma (IFN-gamma), LPS, or combinations of LPS and IFN-gamma at the onset of the cultures, strongly inhibited the production of IL-1 alpha, IL-1 beta, IL-6, IL-8, TNF alpha, GM-CSF, and G-CSF at the transcriptional level. Viral-IL-10, which has similar biological activities on human cells, also inhibited the production of TNF alpha and GM-CSF by monocytes following LPS activation. Activation of monocytes by LPS in the presence of neutralizing anti-IL-10 monoclonal antibodies resulted in the production of higher amounts of cytokines relative to LPS treatment alone, indicating that endogenously produced IL-10 inhibited the production of IL-1 alpha, IL-1 beta, IL-6, IL-8, TNF alpha, GM-CSF, and G-CSF. In addition, IL-10 had autoregulatory effects since it strongly inhibited IL-10 mRNA synthesis in LPS activated monocytes. Furthermore, endogenously produced IL-10 was found to be responsible for the reduction in class II major histocompatibility complex (MHC) expression following activation of monocytes with LPS. Taken together our results indicate that IL-10 has important regulatory effects on immunological and inflammatory responses because of its capacity to downregulate class II MHC expression and to inhibit the production of proinflammatory cytokines by monocytes.
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PMID:Interleukin 10(IL-10) inhibits cytokine synthesis by human monocytes: an autoregulatory role of IL-10 produced by monocytes. 194 Jul 99

The human alveolar macrophage (AM) is an important immune effector cell of the lung, as this cell possesses potent antimicrobial activities and has the ability to present antigen. In addition, the Am can secrete a number of regulatory and chemotactic cytokines in response to both endogenous and exogenous stimuli. In this study, we demonstrate that the adherence of AM to plastic or cellular substrates is an important activation event leading to the gene expression of novel chemotactic cytokine interleukin (IL)-8. The culturing of AM on plastic induced the time-dependent accumulation of IL-8 mRNA. In addition, adherence of these cells induced the gene expression of the proinflammatory cytokines tumor necrosis factor-alpha and IL-1 beta. This adherence phenomenon was not specific to plastic, as AM cultured on collagen- or fibronectin-coated plates also expressed IL-8 mRNA upon adherence. The adherence of Am resulted in the induction of de novo IL-8 mRNA synthesis, as this mRNA accumulation was completely abrogated by actinomycin D. Adherence-induced IL-8 mRNA expression was not altered by cycloheximide, suggesting that de novo or ongoing protein synthesis was not required for induction of IL-8 message. Adherence of AM to plastic not only upregulated IL-8 mRNA levels but also induced the production of extracellular IL-8 immunoreactive protein. Both adherent and nonadherent AM treated with lipopolysaccharide generated substantial amounts of IL-8 mRNA. Adherence and lipopolysaccharide, however, acted in a synergistic fashion to dramatically augment the production of extracellular IL-8 from these cells. Our findings would suggest that AM adherence is an important macrophage-activating event that may play a critical role in the modulation of lung inflammatory responses.
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PMID:Interleukin-8 gene expression from human alveolar macrophages: the role of adherence. 195 85

Expression of the cytokine gene gro, also known as melanoma growth stimulatory activity, is induced by inflammatory stimuli, including IL-1. To determine whether gro expression is regulated at a post-transcriptional level, the effect of IL-1 on gro mRNA stability was examined. Treatment of fibroblasts with IL-1 beta caused a dose-dependent induction of gro mRNA. When IL-1 was withdrawn, gro mRNA decayed rapidly with a half life of 1 hour. This decay occurred whether or not actinomycin D was added to block new transcription. In contrast, when IL-1 was present in the medium, the level of gro mRNA was stable over 8 hours following addition of actinomycin D. In addition, the stability of a related mRNA, IL-8, was found to be regulated by IL-1. To examine whether Northern results reflected expression of gro alpha, or of the closely related genes, gro beta and gro gamma, RNA samples were analyzed by PCR. All three genes were found to be induced by IL-1 and all mRNAs were stabilized in the presence of IL-1. Northern analysis revealed a minor species of gro mRNA which lacked poly(A). The pattern of expression of this RNA suggested that it was a decay intermediate of one or more of the gro mRNAs. The findings indicate that mRNA stabilization is an important component of IL-1 induced gene expression.
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PMID:Post-transcriptional regulation of gro alpha, beta, gamma, and IL-8 mRNAs by IL-1 beta. 201 72

Much effort has been directed toward elucidating the host response to sepsis and inflammation, resulting in the definition of a cascade of endogenous mediators that direct metabolic and immunological responses. Here we report that IL-8, a novel cytokine produced by a variety of cells in vitro in response to stimulation with bacterial LPS and the proinflammatory cytokines, appears in the circulation of primates in vivo during septic shock, sublethal endotoxemia, and after the administration of IL-1 alpha. The magnitude of the IL-8 response correlates with the severity of the insult, and levels of IL-8 peak relatively late, after those of TNF-alpha and IL-1 beta, and simultaneously with those of IL-6. IL-8 has been primarily defined as a selective activator and chemoattractant of neutrophils, and we demonstrate that after LPS or IL-1 alpha infusion, circulating neutrophil numbers rapidly recover from an initial neutropenia while IL-8 concentrations are maximal, supporting the hypothesis that IL-8 influences circulating leukocyte populations in vivo. We conclude that IL-8 is another participant in the cytokine cascade elicited by sepsis and inflammation and, as such, may play a significant role in host defense and disease.
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PMID:IL-8 in septic shock, endotoxemia, and after IL-1 administration. 202 76

Inflammation involving the retina and choroid is a common clinical problem, but the mechanisms that elicit and maintain ocular inflammation remain poorly understood. Interposed between the sensory retina and the systemic blood circulation within the choroid is the neural-derived retinal pigment epithelium (RPE), which forms part of the blood-retina barrier. The RPE is actively phagocytic and shares several features with mononuclear phagocytes of bone marrow origin, including the production of a neutrophil chemotactic factor, interleukin 8, after stimulation with interleukin 1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF-alpha). Because monocyte-derived macrophages are present in retinal lesions of many common and blinding diseases, we monitored human RPE cells or monocyte chemotactic protein (MCP) mRNA expression and activity following cytokine stimulation. Cultured human RPE cells were left unstimulated or exposed to recombinant human IL-1 beta, TNF-alpha, or lipopolysaccharide. MCP mRNA expression in RPE cells and biologically active MCP in RPE cell supernatants were present 1 hour after stimulation and maintained for 24 hours. Conditioned media from RPE cells stimulated with 20 ng/ml of IL-1 beta or TNF-alpha for 24 hours contained biologically active monocyte chemotactic activity that rose rapidly from baseline levels over 4 hours and plateaued over the subsequent 20 hours. RPE chemotactic activity was dose dependent using concentrations of these cytokines ranging from 20 pg/ml to 20 ng/ml of 4-hour assays. Time- and concentration-dependent expression of RPE cell MCP mRNA was also found in the same cultures. Peak MCP mRNA expression occurred after 8 hours of stimulation with IL-1 beta or TNF-alpha. Maximal steady-state MCP mRNA expression occurred at 20 ng/ml for IL-1 beta. Immunohistochemical staining using specific anti-MCP antibodies resulted in distinctive RPE cell staining, confirming the presence of MCP in human RPE cells. These findings demonstrate that cytokine-stimulated RPE cells may evoke or augment mononuclear phagocyte-mediated ocular inflammation by synthesizing MCP.
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PMID:Monocyte chemotactic protein gene expression by cytokine-treated human retinal pigment epithelial cells. 204 33

The protein-bound polysaccharide extracted from a fungus, PSK, has been used as a biological response modifier in the treatment of cancer patients in Japan for over ten years. Although the antitumor mechanism of PSK is not fully understood, host-mediated antitumor activity has been claimed to play a significant role. The administration of PSK to tumor-bearing rodents inhibited tumor growth and modulated immune responses. To clarify the potential immunomodulating activities of PSK, we examined the direct effect of PSK on cytokine gene expression and production in human peripheral blood mononuclear cells (PBMC) in vitro. As determined by Northern blotting, PSK was a potent inducer of gene expression for IL-1 alpha, IL-1 beta, IL-6, IL-8, tumor necrosis factor (TNF-alpha) and monocyte chemotactic and activating factor (MCAF), but not for IL-2 and lymphotoxin (LT). Expression of mRNA occurred at 1-3 hr in a dose dependent manner using from 5-400 micrograms/ml of PSK. Furthermore, these cytokines were also produced in response to PSK as detected by ELISA, RIA or bioassays. We speculate that these cytokines may mediate immunoenhancing actions of PSK in vivo.
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PMID:Induction of gene expression and production of immunomodulating cytokines by PSK in human peripheral blood mononuclear cells. 209 Aug 74


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