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 monocyte chemotactic and activating factor (MCAF) has been purified from TNF-stimulated 8387 human fibrosarcoma cell line-conditioned media. The purified MCAF showed microheterogeneity yielding two bands on SDS-PAGE analysis. Fibrosarcoma-derived MCAF specifically competed with THP-1 (a human monocytic cell line)-derived 125I-labeled MCAF in binding to human PBMC, whereas a similar basic heparin-binding leukocyte chemoattractant, IL-8, did not. The purified MCAF stimulated superoxide anion and N-acetyl beta-D glucosaminidase-releasing activity in human monocytes, as well as monocyte cytostatic augmenting activity against tumor cells and chemotactic activity for monocytes. When injected subcutaneously into Lewis rat ears, the purified human MCAF also induced considerable in vivo local monocyte infiltration beginning at 3 h and becoming maximal at 18 h. In conclusion, the data presented in this paper indicate that MCAF is a potent activator of monocytes as well as a monocyte recruitment factor that acts through receptors that are specific for this novel molecule. This novel cytokine might have an important role in tumor growth control due to its ability to attract and activate monocytes.
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PMID:Properties of monocyte chemotactic and activating factor (MCAF) purified from a human fibrosarcoma cell line. 216 98

Peripheral blood monocytes are important mediators of inflammation via the generation of various bioactive substances, including the recently isolated and cloned chemotactic peptide IL-8. Through cytokine networking, monocyte-derived cytokines are capable of inducing IL-8 expression from non-immune cells. IL-4, a B and T lymphocyte stimulatory factor, has recently been shown to inhibit monocyte/macrophage function, including the ability to suppress monocyte-generated cytokines. We describe the in vitro inhibition of IL-8 gene expression and synthesis from LPS, TNF, and IL-1 stimulated peripheral blood monocytes by IL-4. IL-4 suppressed IL-8 production from stimulated monocytes in a dose-dependent fashion, with partial suppression observed at IL-4 concentrations as low as 10 pg/ml. The IL-4-induced suppressive effects were observed even when IL-4 was administered 2 h post-LPS-stimulation. The IL-4-induced inhibition of IL-8 mRNA expression was dependent on protein synthesis, as the suppressive effects of IL-4 were significantly negated by the addition of cycloheximide. Our findings suggest that IL-4 may be an important endogenous regulator of inflammatory cell recruitment, and adds further support to the potential role of IL-4 as a down-regulator of monocyte immune function.
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PMID:IL-4 inhibits the expression of IL-8 from stimulated human monocytes. 220 Aug 23

The complement receptor type 1 (CR1) surface distribution, density and immune adherence efficiency were determined in circulating PMN activated by fMLP, NAP-1/IL-8, TNF, GM-CSF and C5a, or exudate PMN harvested from skin-blisters. These observations were compared with those observed on resting peri-pheral blood PMN. PMN activators known to upregulate CR1 expression did not induce a significant increase in CR1 clustering, or immune adherence efficiency towards opsonized immune complexes. By contrast, increase in CR1 density at the surface of exudated PMN was accompanied by an increased clustering. This clustering was however insufficient to increase the binding efficiency for immune complexes. Eventually, CR1 expression of exudated neutrophil could not be increased further by stimulation with fMLP or PMA. These results indicated that clustering of CR1 on PMN may occur in vivo. Such reaction might determine the phagocytic potential of the cell for opsonized micro-organisms or debris. This clustering could not be attributed to one of the PMN activators tested.
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PMID:Exudation induces clustering of CR1 receptors at the surface of human polymorphonuclear leukocytes. 224 4

Activated polymorphonuclear neutrophilic granulocytes (PMN) play an important role in propagation of inflammatory reactions and are capable of mediating tissue damage particularly by release of reactive oxygen species and lysosomal contents. Cytokines produced by monocytes as well as epidermal cells were recently shown to modulate PMN function. Therefore, the effect of immunomodulating cytokines on the oxidative metabolism of isolated human PMN was tested by functional as well as ultrastructural criteria. The following recombinant human cytokines were tested: tumor necrosis factor (TNF alpha), lymphotoxin (TNF beta), granulocyte-macrophage colony-stimulating factor (GM-CSF), M-CSF, G-CSF, PDGF, TGF-beta, interleukin-1 (IL-1) alpha and beta, IL-2, IL-3, IL-4, IL-5, IL-6, MONAP/MOC/NAF (IL-8), interferon-alpha and -gamma. Only TNF alpha, TNF beta and GM-CSF were found to be direct stimuli of the oxidative burst in human PMN whereas IL-3, IL-5, and IL-8 were active only at extremely high concentrations. None of the other cytokines tested induced any significant effect on isolated human PMN at physiological concentrations. The results clearly demonstrate that only selected cytokines are capable of inducing a long lasting activation of PMN oxidative metabolism. Release of these mediators represents a specific signal for PMN activation in inflammatory disease states.
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PMID:Activation of the oxidative metabolism in human polymorphonuclear neutrophilic granulocytes: the role of immuno-modulating cytokines. 225 41

To identify possible regulatory sites of the gene expression, we cloned the genomic DNA of human monocyte-derived neutrophil chemotactic factor (MDNCF/IL-8), whose mRNA is induced by IL-1 or TNF and determined its entire nucleotide sequence. The results show that the MDNCF/IL-8 gene consists of 4 exons and 3 introns with a single "CAT"- and "TATA"-like structure. The 5'-flanking region of MDNCF/IL-8 gene shows no overall sequence similarity with that of other cytokine and acute phase reactant genes whose production is also affected by IL-1 and TNF. The 5' flanking region, however, contains potential binding sites for several nuclear factors including activation factor-1, activation factor-2, IFN regulatory factor-1, and hepatocyte nuclear factor-1. In addition, the glucocorticoid responsive element and heat shock element were located in the 5'-flanking region. Inasmuch as PMA induces MDNCF/IL-8 mRNA accumulation in human PBMC and a glucocorticoid inhibits the induction of MDNCF/IL-8 mRNA by LPS, the expression of this gene is probably regulated by interaction of these nuclear factors with the 5'-flanking DNA.
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PMID:Genomic structure of the human monocyte-derived neutrophil chemotactic factor IL-8. 266 93

The influence of human monocyte-derived chemotactic peptide (GCP/IL-8) on degranulation of neutrophils was investigated in relation to that of other monokines. GCP/IL-8 promoted a dose-dependent release of lactoferrin from specific granules but had no effect on enzyme release from primary granules. From the other monokines that were tested, tumour necrosis factor alpha (TNF alpha) also induced degranulation, while IL-1 beta and IL-6 scored negatively. TNF alpha-induced lactoferrin release was enhanced by cytochalasin B pretreatment of the granulocytes, while GCP/IL-8-promoted degranulation was not. In contrast to GCP, TNF alpha also caused the release of LDH, suggesting a non-specific cell destruction. These observations further support the view that, unlike the other monokines, GCP/IL-8 is a true and specific granulocyte activator.
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PMID:Human granulocyte chemotactic peptide (IL-8) as a specific neutrophil degranulator: comparison with other monokines. 267 Jul 52

Epithelia from several sites exhibit inducible secretion of interleukin 8 (IL-8). This study aimed to characterise secretion of IL-8 by colonic epithelial cells in vitro. Colonic crypt cells were isolated enzymatically from resected colon and the IL-8 content of culture supernates was measured by ELISA. The rate of secretion of IL-8 accelerated and levels of IL-8 transcripts increased appreciably during culture. Exposure to tumour necrosis factor alpha (TNF alpha) failed to increase secretion further. Secretion was not induced by the enzymatic digestion or by serum used in the culture medium but was significantly inhibited by butyrate, by a mean of 23%. Control experiments indicated that colonic crypt cells were the likely source. The secretion of IL-8 over 24 hours by cells from uninflamed mucosa of patients with ulcerative colitis or Crohn's disease was more than twofold that from normal cells, while that from cancer bearing colons was normal. TNF alpha (10 mM) significantly suppressed IL-8 secretion only in the ulcerative colitis group and the change was different to those in the normal (p = 0.007) and Crohn's disease groups (p = 0.012). Cells from inflamed areas secreted more IL-8 than those from autologous uninflamed areas (p = 0.009) but responses to modulating factors were no different. The induction of IL-8 secretion by colonic crypt cells in vitro is probably a response to injury associated with isolation and culture. It is suppressed by butyrate and increased in inflammatory bowel disease independently of the presence of mucosal inflammation. Whether epithelial derived IL-8 plays a part in the pathogenesis of inflammatory bowel disease is not yet clear.
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PMID:Interleukin 8 secretion by colonic crypt cells in vitro: response to injury suppressed by butyrate and enhanced in inflammatory bowel disease. 748 42

Human neutrophils at inflammatory sites may be an important source of the chemotactic cytokines macrophage inflammatory protein 1 alpha (M1P-1 alpha; a C-C chemokine) and interleukin 8 (IL-8; a C-X-C chemokine). In this study, we show that the inflammatory microcrystals monosodium urate monohydrate (MSU) and calcium pyrophosphate dihydrate (CPPD), the major mediators of gout and pseudogout, differentially regulate the production of these two chemokines by human neutrophils. Both MSU and CPPD increased the secretion of IL-8 by neutrophils in a dose- and time-dependent manner, but had no effect on that of MIP-1 alpha. Since inflammatory cytokines are likely to be present in the synovium during crystal-induced inflammation, we examined the interaction between TNF-alpha and GM-CSF and the crystals. Both TNF-alpha and GM-CSF stimulated IL-8 production; however, only TNF-alpha exerted a significant effect on MIP-1 alpha secretion in neutrophils. IL-8 production induced by TNF-alpha and GM-CSF was synergistically enhanced in the presence of MSU or CPPD, whereas MIP-1 alpha secretion induced by TNF was completely inhibited in the presence of either MSU or CPPD. Interestingly, no interaction between the crystals and the inflammatory cytokines was observed with respect to synthesis of the C-X-C chemokine MGSA in neutrophils. These results suggest that the combination of TNF-alpha and GM-CSF with MSU or CPPD will lead to the production of IL-8 by neutrophils and abolish the release of MIP-1 alpha, an event that will theoretically lead to recruitment of neutrophils but not mononuclear cells. These results are in accordance with the pathological state of gout and pseudogout, where the predominant inflammatory cell is the neutrophil.
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PMID:Inflammatory microcrystals differentially regulate the secretion of macrophage inflammatory protein 1 and interleukin 8 by human neutrophils: a possible mechanism of neutrophil recruitment to sites of inflammation in synovitis. 750 47

Human tumour necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine capable of killing mammalian tumour cells in vitro and in vivo, and of enhancing the proinflammatory activity of leucocytes and endothelium, the latter effects limiting its usage as an antitumour agent in humans. Using TNF-alpha mutants with a selective capacity to bind to the TNF p55 receptor (TNFR55) or to the p75 receptor (TNFR75) we show here that these two major activities of TNF-alpha can be dissociated. The TNFR55-selective mutants (R32W, E146K and R32W-S86T) which bind poorly to TNFR75 displayed similar potency to wild-type TNF in causing cytotoxicity of a human laryngeal carcinoma-derived cell line (HEp-2) and cytostasis in a human leukaemic cell line (U937). However, these TNFR55-selective mutants exhibited lower proinflammatory activity than wild-type TNF. Specifically, TNF-alpha's priming of human neutrophils for superoxide production and antibody-dependent cell-mediated cytotoxicity, platelet-activating factor synthesis and adhesion to endothelium were reduced by up to 170-fold. Activation of human endothelial cell functions represented by human umbilical venular endothelial cell (HUVEC) adhesiveness for neutrophils, E-selectin expression, neutrophil transmigration and IL-8 secretion were also reduced by up to 280-fold. On the other hand, D143F, a TNFR75-selective mutant tested either alone or in combination with TNFR55-selective mutants, did not stimulate these activities despite being able to cause cytokine production in TNFR75-transfected PC60 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Dissociation of TNF-alpha cytotoxic and proinflammatory activities by p55 receptor- and p75 receptor-selective TNF-alpha mutants. 750 79

Lysophosphatidylcholine (lyso-PC) is a major phospholipid component of atherogenic lipoproteins (e.g., oxidized LDL and beta-VLDL) and also can be generated through the action of leukocyte-secreted phospholipase A2 at sites of inflammation. We have previously reported that lyso-PC can activate cultured endothelia, resulting in the selective upregulation of adhesion molecules, such as vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. In this study, we have found that lyso-PC increased steady state mRNA levels for two smooth muscle/fibroblast-directed growth factors, the A and B chains of PDGF and heparin-binding EGF-like protein (HB-EGF), in cultured human endothelial cells. Lyso-PC did not upregulate the expression of certain other inducible endothelial genes, including E-selectin, IL-8, or monocyte chemoattractant protein-1 in the same cells, in contrast to the coordinate pattern of activation typically observed with other stimuli, such as TNF alpha, bacterial endotoxin, or PMA. Nuclear runoff assays documented an increased transcriptional rate for the HB-EGF gene in lyso-PC-treated cells. Northern blot analyses, after actinomycin D treatment, further indicated that the increased amounts of mRNA for HB-EGF, PDGF A and B chains, and intercellular adhesion molecule-1 were not dependent upon message stabilization. We conclude that lyso-PC can induce growth factor gene expression in cultured endothelial cells and thus may contribute to the migration and proliferation of smooth muscle cells and fibroblasts in various response-to-injury settings in vivo.
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PMID:Lysophosphatidylcholine transcriptionally induces growth factor gene expression in cultured human endothelial cells. 750 51


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