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)

We have previously purified and partially characterized histamine releasing factors (HRF), which were derived from a mixture of human mononuclear cells and platelets. We now report the effect of IL-8 upon HRF-, connective tissue activating peptide III (CTAP III)-, and IL-3-induced histamine release from human basophils. We determined that IL-8 itself, at concentrations between 10(-7) to 10(-11) M, does not release histamine from basophils, although positive results are observed in two of 26 subjects at 10(-7) M. Unfractionated (crude) HRF released histamine in 25 of 26 donors, in the range of 6.7% to 100% of total basophil histamine stores. When basophils were preincubated with IL-8 (10(-7) to 10(-11) M) for 5 min, followed by a 40-min incubation with HRF, histamine release was significantly inhibited in 20 of 25 donors. Inhibition was observed at as little as 10(-11) M IL-8, with maximal inhibition being attained at 10(-9) M. HRF-containing supernatants contain a mixture of different histamine-releasing moieties. To better define which factor(s) may be inhibited by IL-8, fractionated supernatants, purified CTAP III, and IL-3 were studied. Histamine release produced by two different HRF-containing chromatographic fractions (HRFvoid and HRFpeak 2) and purified CTAP-III (5 micrograms/ml) was inhibited by IL-8 in 10 of 12 donors, three of three donors, and seven of 10 donors, respectively. IL-3 (5000 U/ml)-dependent histamine release was inhibited by IL-8 in all subjects tested. In contrast, histamine release by anti-IgE and FMLP was not affected by IL-8. Thus, IL-8 appears to be an inhibitor of cytokine-like molecules that induce histamine release and may represent the previously described 8-kDa histamine release inhibitory factor present in mononuclear cell supernatants.
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PMID:IL-8 inhibits histamine release from human basophils induced by histamine-releasing factors, connective tissue activating peptide III, and IL-3. 171 85

We investigated the response of purified and cloned human thymic epithelial cells (TEC) to IL-1, IL-4, and IFN-gamma stimulation in vitro. IL-1 alpha strongly up-regulated the production of granulocyte-macrophage CSF (GM-CSF), granulocyte CSF (G-CSF), IL-6, and IL-8, as measured by specific immunoenzymetric assays and by increased steady state mRNA levels. IL-4 or IFN-gamma did not induce these cytokines in TEC but in a sustained and dose-dependent manner down-regulated the IL-1-induced GM-CSF protein and mRNA levels. Only IFN-gamma, and not IL-4, suppressed the IL-1-induced G-CSF and IL-8 production, as shown at both the protein and mRNA levels. The inhibition was dose dependent, sustained for at least 96 h, and more pronounced for G-CSF than for IL-8. In contrast, both IL-4 and IFN-gamma enhanced the IL-1-induced IL-6 production. IL-4 and IFN-gamma had additive effects to increase IL-6 secretion and to more completely suppress the IL-1-induced GM-CSF. Analyses of cell surface molecules showed that intercellular adhesion molecule 1 (ICAM-1) expression on TEC was increased by IL-1 or IFN-gamma. IL-4 slightly down-regulated constitutive ICAM-1 levels but did not significantly modify the levels of expression induced by either IL-1 or IFN-gamma. MHC class II expression was induced by IFN-gamma but not by IL-1 or IL-4. The combination of IL-1 and IL-4 with IFN-gamma did not alter the levels of class II MHC Ag induced by IFN-gamma. In conclusion, TEC cytokine production and cell surface molecule expression are differentially regulated via a complex cytokine network. Our data suggest that developing T cells provide, in part, the signals controlling the function of their supporting stroma.
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PMID:IL-1, IL-4, and IFN-gamma differentially regulate cytokine production and cell surface molecule expression in cultured human thymic epithelial cells. 171 90

gamma-Immune protein-10 (gamma-IP10) is a cytokine whose expression has been shown to be induced by interferon-gamma. It is a member of a group of closely related cytokines (e.g., interleukin 8 and platelet factor 4) with chemotactic properties. gamma-IP10 has been detected in keratinocytes, lymphocytes, monocytes, and endothelial cells in immunologically mediated processes, such as positive tuberculin skin tests, and in growth-activated keratinocytes, such as in psoriasis. Keratinocytes in normal epidermis do not produce gamma-IP10. We tested the hypothesis that keratinocytes adjacent to dysplastic nevi and melanomas would produce gamma-IP10, perhaps as part of an immune response to a tumor, and that this response would not be seen in ordinary melanocytic nevi. We used an affinity-purified, polyclonal rabbit anti-gamma-IP10 antibody to examine 10 nevi with moderate to severe histologic dysplasia, one superficial spreading melanoma, and 10 compound melanocytic nevi with no features of dysplasia. As predicted, keratinocytes surrounding all of the cytologically atypical melanocytic lesions displayed strong staining with gamma-IP10. There was no staining of keratinocytes adjacent to ordinary melanocytic nevi. The observed keratinocyte staining with gamma-IP10 may be related to a host immune response to antigenically abnormal cells.
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PMID:Detection of cytokine-induced protein gamma-immune protein-10 (gamma-IP10) in atypical melanocytic proliferations. 172 47

The capacity of human monocytes/macrophages (M/M) infected with a human immunodeficiency virus-1 (HIV-1) isolate to produce several immunomodulating cytokines including interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-8, and macrophage chemoattractant and activating factor (MCAF) was examined. Although HIV infection itself induced significant increases in the level of mRNAs for IL-1 beta, TNF-alpha, IL-6, and IL-8, the levels of lipopolysaccharide (LPS)-induced mRNAs for IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, IL-8, and MCAF were decreased over those of uninfected LPS-stimulated cells. In addition, HIV-infected M/M produced lower amounts of IL-8 protein, as measured by radioimmunoassay over an 18-day culture period. These results suggest that HIV infection generally suppresses the LPS-inducible cytokine production in human M/M. The impact of the role of these cytokines in the immunity and pathogenesis of HIV-1 infection is discussed.
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PMID:Decrease in cytokine production by HIV-infected macrophages in response to LPS-mediated activation. 172 30

Injury to cartilage is a recognized sequela of neutrophil activation in arthritic joints. This study examined the possibility that chondrocytes may play a direct role in intraarticular neutrophil activation. We demonstrate that IL-1 beta-stimulated primary and subcultured human articular chondrocytes, express the gene for the potent neutrophil chemotactic and activating cytokine, IL-8. Expression of IL-8 mRNA is also inducible by TNF-alpha and LPS and, to a lesser degree, by the chondrocyte growth factor, transforming growth factor-beta, but not by platelet-derived growth factor, acidic and basic fibroblast growth factor, or epidermal growth factor. Analysis of IL-1 beta-stimulated cartilage organ cultures by in situ hybridization demonstrates that chondrocytes in all zones of cartilage are rapidly induced to express the IL-8 gene in high copy number. Metabolically labeled IL-1 beta-stimulated chondrocytes synthesize IL-8 de novo, which comigrates on SDS-PAGE with IL-8 produced by synovial fibroblasts. Furthermore, the conditioned media of IL-1 beta-stimulated chondrocytes and cartilage organ cultures contain neutrophil chemotactic activity which is completely neutralized by a specific antibody to IL-8, establishing that a bioactive form of IL-8 is the major secreted neutrophil chemotactic factor. By using a specific RIA, we demonstrate that not only IL-1 beta, but also TNF-alpha and LPS can induce abundant IL-8 secretion from chondrocytes. In conclusion, articular chondrocytes are readily inducible to express the IL-8 gene and secrete biologically active IL-8 which can promote neutrophil-mediated inflammation and cartilage destruction.
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PMID:Cartilage and joint inflammation. Regulation of IL-8 expression by human articular chondrocytes. 172 66

Cells in the rheumatoid synovium express high levels of major histocompatibility complex (MHC) class II molecules in vivo. We have therefore examined the ability of engagement of MHC class II molecules by the superantigen Staphylococcal enterotoxin A (SEA) to activate interleukin 6 (IL-6) and IL-8 gene expression in type B synoviocytes isolated from patients with rheumatoid arthritis. SEA had a minimal or undetectable effect on the expression of either gene in resting synoviocytes, as determined by Northern blot and specific enzyme-linked immunosorbent assay. However, induction of MHC class II molecule expression after treatment of synoviocytes with interferon gamma (IFN-gamma) enabled the cells to respond to SEA in a dose-dependent manner, resulting in an increase in both the level of steady-state mRNA for IL-6 and IL-8, and the release of these cytokines into the supernatant. IFN-gamma by itself had no effect on the expression of either cytokine. Pretreatment of the cells with the transcription inhibitor actinomycin D prevented the increase in cytokine mRNA induced by SEA, whereas cycloheximide superinduced mRNA for both cytokines after stimulation by SEA. Taken together, these results indicate that signaling through MHC class II molecules may represent a novel mechanism by which inflammatory cytokine production is regulated in type B rheumatoid synoviocytes, and potentially provides insight into the manner by which superantigens may initiate and/or propagate autoimmune diseases.
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PMID:Engagement of major histocompatibility complex class II molecules by superantigen induces inflammatory cytokine gene expression in human rheumatoid fibroblast-like synoviocytes. 173 19

IL-8 is a proinflammatory cytokine that functions as a chemoattractant for neutrophils. Recently, cDNA clones encoding the human neutrophil IL-8R were isolated by an expression cloning strategy. The amino acid sequence of the human IL-8R was sufficiently similar to a published sequence for an isoform of the rabbit FMLP receptor that we considered the possibility that the rabbit sequence might bind IL-8 as well. In order to establish its ligand specificity, we have isolated and characterized cDNA clones encoding the rabbit receptor. These cDNA clones, when expressed in mammalian cells, confer high affinity IL-8 binding (Kd = 3.6 nM), lack detectable binding of FMLP, and produce a transient increase in the intracellular Ca2+ concentration in response to IL-8 but not to FMLP. These data demonstrate that the reported rabbit FMLP receptor is the rabbit IL-8R, not an isoform of the FMLP receptor. In addition, the amino acid sequence of the rabbit IL-8R encoded by these cDNA clones differs at 23 amino acids (of 355) from that previously published.
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PMID:Characterization of complementary DNA clones encoding the rabbit IL-8 receptor. 173 38

Chemotactic cytokines play a critical role in recruiting leukocytes to sites of tissue injury. Interleukin-8 (IL-8) is a chemotactic cytokine secreted by a variety of cells (eg, monocytes, endothelial cells, fibroblasts) during the inflammatory response. In this report, the authors demonstrate that human transitional cell carcinomas and renal cell carcinomas have the capacity to elaborate IL-8 in response to the inflammatory mediators IL-1 beta and tumor necrosis factor (TNF)-alpha. All cell lines expressed high levels of IL-8 mRNA on stimulation with either IL-1 beta or TNF-alpha, but not lipopolysaccharide; one expressed the gene constitutively. The authors selected one transitional cell carcinoma cell line (UM-UC-9) and one renal cell carcinoma cell line (UM-RC-5) for further study. Both displayed a time- and dose-dependent increase in steady-state levels of IL-8 mRNA in response to IL-1 beta and TNF-alpha. Specific mRNA was detectable by 1 hour after stimulation. Secretion of antigenic IL-8 measured by enzyme-linked immunosorbent assay into culture supernatants reflected the kinetics of mRNA expression. Because heat-inactivated TNF-alpha failed to induce synthesis of IL-8 mRNA, and cycloheximide augmented TNF-alpha-induced synthesis, IL-8 expression appears to be a stimulus-specific primary induction phenomenon. As with other inflammatory mediators whose mRNA contains a 3' AU-rich sequence (eg, IL-2, TNF-alpha), the half-life of IL-8 mRNA was short, less than 1 hour. Our data suggest that secretion of IL-8 by malignant cells may partly account for the inflammatory infiltrates associated with some malignant neoplasms.
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PMID:Cytokine-induced gene expression of interleukin-8 in human transitional cell carcinomas and renal cell carcinomas. 173 30

The present study was designed to investigate the effect of membrane proteoglycans (MPG) from Klebsiella pneumoniae on production of the chemotactic cytokine, IL-8, and monocyte chemotactic protein (MCP) by human peripheral blood monocytes. Exposure of human peripheral blood monocytes to MPG in vitro induced high levels of mRNA transcripts for IL-8 and MCP, as assessed by Northern blot analysis. Cytokine gene expression was associated with the production of chemotactic activity in the supernatants. The levels of IL-8 and MCP expression induced by MPG were comparable with those elicited by LPS. Induction of chemotactic cytokines in mononuclear phagocytes may play a role in the immunomodulatory activity of MPG.
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PMID:Chemotactic cytokine gene expression and production induced in human monocytes by membrane proteoglycans from Klebsiella pneumoniae. 175 2

Human alveolar macrophages (AM) are susceptible to infection with respiratory syncytial virus (RSV), but the infection is abortive after the initial cycles of virus replication. We have investigated if RSV infection of AM results in the production of cytokines TNF, IL-6, and IL-8, all of which may modulate inflammatory and immune responses to the virus, as well as may directly protect respiratory epithelial cells against spread of infection. Within 1 h after interaction with RSV, increased mRNA levels were found for all three cytokines. Peak expression of the mRNAs occurred at 3 to 6 h. The virus most effectively induced TNF mRNA expression greater than IL-6 mRNA greater than IL-8 mRNA, as compared to cytokine mRNA expression induced by bacterial endotoxin. Inactivated virus was almost as effective as live virus in inducing and maintaining increased IL-6 and IL-8 mRNA over 16 h, whereas live infectious RSV was necessary for maintaining TNF mRNA expression over the same time. Protein concentrations of the different cytokines in the supernatants of infected AM reflected the increased levels of mRNA in the cells. Despite the high levels of cytokines with possible antiviral activity (TNF and IL-6) in the AM supernatants, neither supernatants nor rTNF when added to bronchial epithelial cells protected them from infection with RSV. However, TNF, IL-1, and RSV, but not IL-6, induced IL-8 and IL-6 mRNA expression by the bronchial epithelial cells suggesting that cytokines produced by RSV-infected AM may be more important in modulating the inflammatory response in infection than directly interfering with virus infection/replication of airway epithelium.
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PMID:Cytokine (tumor necrosis factor, IL-6, and IL-8) production by respiratory syncytial virus-infected human alveolar macrophages. 175 1


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