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Query: UNIPROT:P10145 (IL-8)
 23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Whatever initiates inflammation, the final message mediating cellular invasion is chemical. This consideration allows rational development of anti-inflammatory treatments. Two main classes of chemotactic mediator are recognised. Water-soluble peptides, e.g. cytokines derived from macrophages and other cells, play an important integrating part in the early recruitment of neutrophils and mononuclear cells, and in the amplification of immune responses. Lipid-soluble mediators, of which leukotriene B4 is the most highly chemotactic for neutrophils, are important in secondary amplification. In inflammatory bowel disease, we have shown evidence of increased synthesis of cytokines interleukin 1, 6 and 8. These are associated with activation of circulating monocytes in active Crohn's disease, of lamina propria macrophages in relapse of both ulcerative colitis and Crohn's disease, and development of adhesion molecules on vascular endothelium. Our studies show that interleukin 6 is selectively increased in Crohn's disease, whilst preliminary findings suggest that enhanced synthesis of interleukin 8 is particularly characteristic of ulcerative colitis. Patterns of cytokine synthesis may, therefore, be of diagnostic value. They also offer the potential for therapeutic strategies since cytokine antagonists are becoming available. We have also demonstrated increased synthesis of leukotrienes in active inflammatory bowel disease. Since leukotriene B4 is quantitatively the main chemotactic signal in the mucosa in inflammatory bowel disease during relapse, we investigated the therapeutic effect of suppressing leukotriene B4 synthesis by treating patients with fish oil (as Hi-EPA), giving 4.5 g daily of eicosapentaenoic acid. This competes for the 5-lipoxygenase enzymes, inhibiting leukotriene B4 and promoting synthesis of the less chemotactic product, LTB5.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Therapeutic interventions in gastrointestinal disease based on an understanding of inflammatory mediators. 135 43

Cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage-CSF (M-CSF), neutrophil-activating peptide-1/interleukin-8 (NAP-1/IL-8), and interleukin-6 (IL-6) are pivotal in the regulation of hematopoiesis and immune responses. In mesenchymal cells, their expression is induced by tumor necrosis factor alpha (TNF) and other agents. We now show that, while induction of cytokine expression by TNF in human lung fibroblasts was parallel, glucocorticoid hormones differentially affected their production. Dexamethasone (1 mumol/L) concordantly repressed expression of GM-CSF, NAP-1/IL-8 and IL-6. RNA and protein levels were reduced to approximately 5%, 20%, and 30% of control cells, respectively, as determined by Northern blot analyses and immunoassays. A 50% reduction of RNA levels for all three cytokines occurred in the range of 1 hour. In contrast, dexamethasone (1 mumol/L) did not decrease M-CSF RNA levels and protein release. M-CSF RNA and protein levels were maintained even when dexamethasone (1 mumol/L) was present for the whole duration of a 48-hour TNF stimulation. Further experiments showed that dexamethasone downregulates expression of GM-CSF, NAP-1/IL-8, and IL-6 mainly by decreasing the mRNA stability of these cytokines, and that the dexamethasone-mediated repression of cytokine expression depends on ongoing protein and RNA syntheses. Our study suggests that glucocorticoid hormones repress expression of a set of cytokine genes important in conditions of stress. However, they seem not to affect M-CSF expression, which is likely to be more crucial in maintaining long-term functions of myeloid cells.
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PMID:Glucocorticoids downregulate gene expression of GM-CSF, NAP-1/IL-8, and IL-6, but not of M-CSF in human fibroblasts. 137 Feb 8

The present study was designed to investigate the capacity of human mononuclear phagocytes to produce a cytokine chemotactic for monocytes (monocyte chemotactic protein (MCP), alternative acronyms JE, monocyte chemotactic and activating factor, MCP-1, and tumor-derived chemotactic factor). Human PBMC exposed in vitro to bacterial LPS expressed high levels of MCP transcripts. Monocyte-depleted lymphoid cells were not induced to express MCP by LPS. Percoll-gradient purified monocytes were able to express high levels of MCP transcripts. In an effort to exclude a role of contaminating non-monocytic cells, mononuclear phagocytes were separated by flow cytometry and sorting: CD14+ cells exposed to LPS showed high levels of MCP mRNA. LPS-stimulated monocytes released chemotactic activity for monocytes that could be inhibited by absorption with anti-MCP antibodies. IL-1, TNF, IFN-gamma, granulocyte-macrophage-CSF and, to a lesser extent, macrophage-CSF, as well as inactivated streptococci, also induced MCP gene expression. Actinomycin D experiments indicated that induction of MCP in monocytes was gene transcription-dependent. The protein synthesis inhibitor cycloheximide (Cy) blocked IL-1-, TNF-, or LPS-induced MCP gene expression in monocytes. In contrast, expression of the structurally related chemotactic cytokine IL-8 was superinduced by Cy. Moreover, Cy superinduced MCP gene expression in cells other than monocytes, including endothelial cells, smooth muscle cell and fibrosarcoma cells, indicating different mechanisms of regulation in mononuclear phagocytes vs cells of other lineages. The capacity of cells of the monocyte-macrophage lineage to produce a cytokine that recruits and activates circulating monocytes may be of considerable importance in inflammatory and immunologic reactions. Thus, the mononuclear phagocyte system can autonomously regulate the extravasation and activation of immature elements of the same lineage, a key event in inflammation and immunity.
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PMID:Expression of a monocyte chemotactic cytokine by human mononuclear phagocytes. 137 May 16

Thrombin stimulation of human platelets results in the release of a preformed proteinaceous human eosinophil (Eo)-chemotactic activity. By the use of different high-performance liquid chromatography techniques, two Eo-chemotactic polypeptides (EoCPs), tentatively termed EoCP-1 and EoCP-2, were purified to homogeneity. Upon SDS-PAGE analysis, these chemotaxins showed molecular masses near 8 kD. NH2-terminal amino acid sequence analysis revealed identical sequences for both EoCP-1 and EoCP-2, which are also identical to that of RANTES, a cytokine that structurally belongs to the interleukin 8 superfamily of leukocyte selective attractants, and that is known to be a "memory-type" T lymphocyte-selective attractant. In the major Eo chemotaxin, EoCP-1, the residues 4 and 5, which in EoCP-2 were found to be serine residues, could not be identified. Electrospray mass spectrometry (ESP-MS) of EoCPs revealed for EoCP-2 a molecular mass of 7,862.8 +/- 1.1 daltons, which is 15.8 mass units higher than the calculated value of RANTES, indicating that EoCP-2 is identical to the full-length cytokine, and oxygenation, probably at methionine residue number 64, has taken place. Upon ESP-MS, EoCP-1 showed an average molecular mass of 8,355 +/- 10 daltons, suggesting O-glycosylation at these serine residues. Both natural forms of RANTES showed strong Eo-chemotactic activity (ED50 = 2 nM) with optimal chemotactic migration at concentrations near 10 nM, however, there were no significant migratory responses with human neutrophils. Chemotactic activity of RANTES for human Eos could be confirmed using recombinant material, which has been found to be as active as the natural forms. Since RANTES gene expression has been detected in activated T lymphocytes, and recombinant RANTES was shown to be a "memory" T lymphocyte-selective attractant, it is now tempting to speculate about an important role of RANTES in clinical situations such as allergene-induced late-phase skin reactions in atopic subjects or asthma, where in affected tissues both memory T cells and Eos are characteristic.
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PMID:Cytokine RANTES released by thrombin-stimulated platelets is a potent attractant for human eosinophils. 138 64

We have previously reported that cytokine- or LPS-activated human umbilical vein endothelial cell (HUVEC) monolayers secrete IL-8 that can act as a neutrophil-selective adhesion inhibitor. In our study we investigated the mechanisms involved in the leukocyte adhesion inhibitory action of IL-8. The leukocyte adhesion inhibitory effect appears to be mediated by the action of IL-8 on the neutrophil, does not involve down-regulation of relevant endothelial adhesion molecules such as endothelial-leukocyte adhesion molecule-1 or intercellular adhesion molecule-1, and is quantitatively similar in different endothelial activation states that are predominantly endothelial-leukocyte adhesion molecule-1 dependent or intercellular adhesion molecule-1 dependent. In addition to inhibiting the attachment of freshly isolated peripheral blood neutrophils to cytokine-activated HUVEC monolayers, IL-8 also promoted a rapid detachment of tightly adherent neutrophils from activated HUVEC, and abolished neutrophil transendothelial migration. Certain other chemoattractants, including FMLP and C5a, had similar inhibitory actions, indicating IL-8 was not unique in its ability to inhibit various neutrophil-endothelial interactions. In contrast, two other neutrophil agonists 1-0-alkyl-2-acetyl sn-glycero-3-phosphocholine and granulocyte-macrophage-CSF, which, like IL-8, are produced by activated HUVEC, as well as the leukocyte-derived chemoattractant leukotriene B4, exerted minimal inhibitory effects on adhesion. Regardless of their ability to modulate neutrophil-endothelial cell adhesion, all these agents induced altered leukocyte surface expression of functionally important adhesion molecules, including loss of L-selectin (leukocyte adhesion molecule-1, LECAM-1) and increase in CD11b/CD18. Thus, although the above agonists have been characterized primarily as chemoattractants, our findings demonstrate that these agents can exert a wide range of modulatory effects on neutrophil-endothelial adhesive interactions.
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PMID:In vitro inhibitory effect of IL-8 and other chemoattractants on neutrophil-endothelial adhesive interactions. 138 98

Astrocyte-enriched populations were established from human embryonic brain analyzed for their ability to synthesize cytokines potentially relevant for mechanisms of inflammation and immunity in the brain. Unstimulated astrocytes did not secrete significant IL-6, IL-8, macrophage CSF (M-CSF), granulocyte-macrophage CSF (GM-CSF), or granulocyte-CSF (G-CSF), as determined by specific ELISA and/or bioassay. With the exception of M-CSF mRNA, transcripts for the above factors were not detected in unstimulated astrocytes. On exposure of human astrocytes to IL-1 beta, high levels of IL-6, IL-8, M-CSF, G-CSF, and GM-CSF mRNAs were detected; moreover, active secretion of all the above cytokines was demonstrated. TNF-alpha was also able to stimulate IL-6, IL-8, M-CSF, GM-CSF, and G-CSF synthesis and secretion, but was generally less potent than IL-1 beta. No IL-3 mRNA or protein was detected in unstimulated or cytokine-treated astrocytes. IL-1 alpha and IL-1 beta mRNAs and proteins were not detected in unstimulated astrocytes, but were present in very small amounts after stimulation with TNF-alpha/IL-1 beta. No IL-6, M-CSF, GM-CSF, G-CSF, or IL-8 were induced by IL-1 beta or TNF-alpha in early primary cultures, which mainly contain undifferentiated neuronal/glial progenitor cells. These studies demonstrate for the first time the production of multiple cytokines by normal human astrocytes stimulated in culture by IL-1 beta and TNF-alpha. The capacity of human astrocytes to synthesize and release cytokines active on hemolymphopoietic cells supports the concept that these cells play an important role in the regulation of inflammatory and immune responses in a variety of brain pathologies.
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PMID:Production of hemolymphopoietic cytokines (IL-6, IL-8, colony-stimulating factors) by normal human astrocytes in response to IL-1 beta and tumor necrosis factor-alpha. 138 99

Interleukin-8 (IL-8) is a chemotactic and activating cytokine for neutrophils, which plays an important role in acute inflammatory responses. We aimed to develop a sensitive enzyme-linked immunosorbent assay (ELISA) for IL-8 and established 18 clones of anti-IL-8 monoclonal antibodies (mAbs). These mAbs were evaluated in terms of their antigen-binding affinities, and five clones were selected and used for the comparative study of various combinations of antibodies in sandwich ELISA. Affinity purified rabbit polyclonal antibody was also used in this study. One antibody pair, which showed relatively high sensitivity and which was not severely interfered with blood components, was selected and the assay conditions were optimized by choosing the appropriate buffer for sample dilution and by directly labeling the second antibody with enzyme. The finalized ELISA, using polyclonal antibody as first (coated) antibody and horseradish peroxidase-labeled mAb (clone EL139) Fab' fragment as second antibody, could detect as low as 2.5 pg/ml (0.125 pg/well) of IL-8 by in total 2 h incubation, without being affected by body fluid components. The ELISA was specific to IL-8, showing no cross-reactivity with other cytokines or various IL-8 family proteins which share some amino acid sequence homology with IL-8. As an example of its application to clinical specimens, plasma samples from patients with septic shock were measured. The results showed that sepsis patients contain significantly higher levels of plasma IL-8 compared to normal controls. When analyzed by gel-filtration chromatography, IL-8 in sepsis plasma was eluted in a molecular weight (M(r) region corresponding to the monomer form. The ELISA established here is expected to be effectively used for further investigations on the relationship between IL-8 and various diseases.
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PMID:A highly sensitive enzyme-linked immunosorbent assay for the measurement of interleukin-8 in biological fluids. 138 37

Activation of human monocytes with LPS induces coordinate expression of a number of cytokine genes, including IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, and IL-8. The T cell-derived lymphokine, IL-4, inhibits expression of these genes in monocytes, suggesting that it may be an important physiologic regulator of cytokine production. We have previously shown that IL-4 reduces steady state messenger RNA (mRNA) levels for IL-1 beta in human monocytes by decreasing both IL-1 beta transcription and the t1/2 of newly formed IL-1 beta mRNA transcripts. In the present study, we extend these findings to show that IL-4 similarly accelerates the turnover of IL-6 mRNA in LPS-stimulated monocytes. However, this inhibition of cytokine expression and dramatic increase in the decay rate of cytokine mRNA does not extend to all LPS-inducible genes because IL-4 treatment did not inhibit the expression or accelerate the turnover of mRNA for the IL-1 receptor antagonist (IL-1ra) in the same cells. Although IL-1 beta and IL-1Ra are both LPS-inducible genes, they displayed distinct temporal patterns of expression. Peak steady state mRNA levels for IL-1ra lagged significantly behind that of IL-1 beta, suggesting a possible endogenous mechanism for limiting IL-1 biologic activity. Furthermore, although IL-4 suppressed expression of both IL-1 beta and IL-6, it up-regulated synthesis of IL-1ra mRNA and protein. Thus, IL-4 inhibits production of the proinflammatory cytokine, IL-1 beta, while concomitantly enhancing synthesis of the IL-1ra in activated human monocytes.
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PMID:IL-4 reciprocally regulates IL-1 and IL-1 receptor antagonist expression in human monocytes. 138 62

In preterm deliveries, we have reported a high incidence (30-50%) of histologic chorioamnionitis (CAM) in the placenta. There is little evidence about the effects of CAM on preterm infants. We investigated the levels of complements and cytokines in the cord blood, the pathological nature of the placenta, the L/S ratio of gastric and tracheal aspirate of each preterm infant at birth, and assessed the biological effects of CAM on them. CAM stimulates the immunological system by cytokine production (IL6 and IL8) and complement activation in the fetus. It has been suggested that CAM may be one of the factor accelerating fetal maturation of the immunological system such as complement activation and immunoglobulin production, and of surfactant synthesis in the lung. On the contrary, CAM may damage the structures along the lining cells in the airway by accumulating polymorphonuclear cells of the infants with Wilson-Mikity syndrome.
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PMID:Significance of chorioamnionitis. 139 24

The synovial fluid aspirated from patients with symptomatic arthritis was analyzed for the presence of tumor necrosis factor (TNF), interleukin 6 (IL-6) and interleukin 8 (IL-8). All three cytokines were found in both inflammatory and non-inflammatory arthritides: IL-8 levels ranged from less than 20 to 38,990 pg/ml, IL-6 from less than 10 to 72,300 pg/ml and TNF from less than 4 to 61 pg/ml. No inhibitors of cytokine activity were found. IL-8 and IL-6 were present in significantly higher levels in patients with inflammatory arthritis compared to patients with osteoarthritis, and there was significant correlation between the IL-6 and IL-8 levels. These findings document the presence of multiple cytokines in the synovial fluid specimens of patients with arthritis, and demonstrate that higher cytokine levels accompany inflammatory arthritis.
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PMID:Profile of cytokines in synovial fluid specimens from patients with arthritis. Interleukin 8 (IL-8) and IL-6 correlate with inflammatory arthritides. 139 81


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