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)

The measurement of cytokine mRNA levels is of fundamental importance in the understanding of diverse pathological states. We present a simplification of a polymerase chain reaction-based technique which permits the simultaneous measurement of up to 20 cytokine mRNAs, together with those of several other cellular products, including beta 2-microglobulin and beta-actin. The technique makes use of internal standards bearing multiple PCR primer sites which are identical to those on the mRNAs to be assayed. Known quantities of the standards are added to the cellular RNA and the mixture is co-reverse transcribed and co-amplified. The simplifications described here are based on the fact that each pair of amplicons accumulates in a constant ratio even in the plateau phase of amplification. As a result, no preliminary experiments to determine the limits of the exponential phase of amplification are necessary; the same number of cycles may be chosen for all the mRNAs to be measured, whatever their level in the mixture might be; pipetting errors are avoided since all calculations are based upon the relative quantities of co-amplified material. Here we illustrate the method through a quantitative study of the expression of cytokine mRNAs in U373 human astrocytoma cells before and after stimulation with IL-1 beta. Quantitation was carried out either by incorporating radioactivity in the amplicons or by fluorescence measurements after propidium iodide staining. Only very low numbers of transcripts for IL-6, IL-8, CSF-1, MCP-1 and either Gro alpha or Gro beta were detectable in unstimulated cells. The levels of these cytokine mRNAs increased dramatically following IL-1 beta stimulation and, in addition, transcription of IL-1 beta, TNF alpha, GM-CSF, G-CSF, Gro gamma and MCP-1, some of which have not previously been detected in U373, was initiated in the stimulated cells. At the same time we found that transcripts for IL-2, IL-3, IL-4, IL-5, IFN gamma, huMlP1 alpha and huMlP1 beta were totally absent in this cell line. These results suggest a potentially important role for astrocytes in the local amplification of inflammatory responses in the brain.
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PMID:Simultaneous quantitation of cytokine mRNAs in interleukin-1 beta stimulated U373 human astrocytoma cells by a polymerisation chain reaction method involving co-amplification with an internal multi-specific control. 129 3

Basophil chemotactic activity (BCA) of eight recombinant human (rh) cytokines was examined. Highly purified basophils were obtained by Percoll discontinuous gradients, followed by negative selection using flow cytometry. Then BCA was measured by means of modified Boyden chamber method. Both interleukin (IL)-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF) had much more potent BCA than complement C5a, leukotriene B4 and platelet activating factor, well known as granulocyte chemotactic factors. Chemotaxis rather than chemokinesis was shown in chequerboard analysis of basophil migration induced by IL-3 and GM-CSF. Relatively high concentrations of IL-5 also induced basophil migration, although predominantly chemokinetic. IL-8 had apparent BCA, which was not so high as that of C5a. In contrast, IL-2, IL-4, interferon(IFN)-gamma and granulocyte colony-stimulating factor (G-CSF) had no significant BCA. These findings suggest that IL-3, IL-5, GM-CSF and, perhaps, IL-8 have an effect on basophil migration as well as modulation of basophil mediator release and may provide some insight into the basophil accumulation observed in late-phase allergic responses.
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PMID:Effects of cytokines on human basophil chemotaxis. 133 81

The effect of interleukin 8 (IL-8) on IL-4-induced immunoglobulin E (IgE) production was studied. IL-4 induced IgE and IgG4 production by tonsillar mononuclear cells (MNC) without affecting IgM, IgG1, IgA, IgG2, or IgG3 production. IL-8 inhibited IL-4-induced IgE and IgG4 production, whereas it had no effect on IgM, IgG1, IgA, IgG2, and IgG3 production. The inhibitory effect by IL-8 was specific, since it was blocked by anti-IL-8 mAb, but not by control IgG1. Although interferon gamma (IFN-gamma) also inhibited IgE and IgG4 production by MNC stimulated with IL-4, the inhibitory effect of IL-8 was not mediated by IFN-gamma, since the IL-8-induced inhibition could not be blocked by anti-IFN-gamma. Furthermore, anti-IL-8 mAb had no effect on IFN-gamma-induced inhibition. Moreover, addition of IL-5 or IL-6 did not reverse IL-8-induced inhibition of IgE production. In contrast to these observations with MNC, IL-4 failed to induce IgE and IgG4 production by purified B cells. However, combined treatment of purified B cells cells with IL-4 and anti-CD40 antibody resulted in IgE but not IgG4 production. IL-8 inhibited this IgE production without affecting IgM, IgG1, IgG2, IgG3, IgG4, or IgA production, whereas IFN-gamma, IFN-alpha, or prostaglandin E2 (PGE2) failed to do so. These results indicate that IL-8 antagonizes IL-4-induced IgE production by directly affecting B cells through a specific mechanism that is different from IFN-gamma, IFN-alpha, or PGE2.
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PMID:Interleukin 8 (IL-8) selectively inhibits immunoglobulin E production induced by IL-4 in human B cells. 138 79

Histamine and putrescine (a precursor of polyamines) are formed by histidine decarboxylase (HDC) and ornithine decarboxylase (ODC), respectively. Within a few hours after injection of a lipopolysaccharide (LPS) into mice, HDC is induced in the liver, spleen, lung and bone marrow, and ODC is induced in the liver, spleen and bone marrow. Since LPS is known to stimulate the production of various cytokines, the abilities of various cytokines to induce HDC and ODC in the tissues of mice were examined. IL-2, IL-6, IL-8, IFN gamma and M-CSF were ineffective. IL-1 alpha, IL-1 beta, TNF alpha and TNF beta induced HDC and ODC, as does LPS. On the other hand, GM-CSF and G-CSF induced HDC and ODC only in the spleen and bone marrow within a few hours after their injection. These results suggest that, in addition to their roles in inflammation or immune responses, HDC and ODC are also involved in an early stage of hematopoiesis.
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PMID:GM-CSF and G-CSF stimulate the synthesis of histamine and putrescine in the hematopoietic organs in vivo. 138 20

The chemotactic cytokine interleukin 8 (IL-8) is produced upon stimulation by various agents in many cell types, including connective-tissue fibroblasts. Tumor necrosis factor (TNF) and IL-1 are potent inducers of IL-8 expression. Earlier we showed that TNF-induced stimulation of IL-8 mRNA accumulation in human FS-4 fibroblasts was inhibited by interferon beta (IFN-beta) or IFN-gamma. Here we show that this inhibition is not specific for TNF, since IFN-beta also reduced IL-8 mRNA accumulation induced by IL-1 or the double-stranded RNA poly (I-C). Treatment with IFN-beta also decreased TNF-induced IL-8 protein accumulation. Interestingly, the inhibitory effect was much less pronounced when IFN-beta was added greater than or equal to 1 hr before TNF. The inhibitory action of IFN-beta on IL-8 mRNA accumulation was undiminished in the presence of inhibitors of protein synthesis. Nuclear run-on assays demonstrated that IFN-beta caused a marked inhibition of TNF-induced IL-8 gene transcription; the transcriptional activation of several other TNF-induced genes was not inhibited by IFN-beta. The results suggest that the specific inhibition of the transcriptional activation of IL-8 by IFN is due either to a transient inactivation of a factor required for IL-8 transcription or to the activation of a selective inhibitory factor.
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PMID:Downregulation of interleukin 8 gene expression in human fibroblasts: unique mechanism of transcriptional inhibition by interferon. 140 1

LD78 is a small secreted protein that has a sequence similar to a number of other polypeptides, including murine macrophage inflammatory protein 1 alpha (MIP-1 alpha), interleukin 8 (IL-8), Act-2, monocyte chemoattractant protein 1 (MCP-1), and others. These polypeptides are members of a novel cytokine superfamily that is involved in the inflammatory response, wound healing, hematopoiesis, and tumorigenesis. Specific receptors for purified clonal LD78 protein were measured using four cell lines (HL-60, U937, Jurkat, and MJ). 125I-labeled recombinant LD78 bound most efficiently to U937 cells. We therefore characterized the receptors as being on the surface of U937 cells. Binding reached an equilibrium after incubation for 60 min at 4 degrees C. Scatchard analysis showed that there were two classes of binding sites on U937 cells, high affinity sites (Kd = 5.3 x 10(-9) M) and low affinity sites (Kd = 9.3 x 10(-8) M), with the average number of binding sites per cell being approximately 30,000 and approximately 90,000, respectively. These receptors for LD78 were distinct from the receptors for gamma-IFN and for IL-8. SDS-PAGE analysis of chemically crosslinked 125I-labeled LD78 receptor complexes identified a single band of 52 kDa. The ability to detect specific LD78 receptors should prove valuable in efforts to molecularly clone these receptors and to dissect the biological actions of LD78.
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PMID:Identification and characterization of specific receptors for the LD78 cytokine. 151 Nov 63

It is evident from this review that TNF exhibits complex interactions with other cytokines at the level of production and in its effects. Studies designed to determine the role of TNF in the animal models or cell culture system using pure recombinant molecules have revealed that TNF never operates by itself, but instead operates within a network of cytokines. First, the multitude of exogenous as well as endogenous signals, which induce TNF production, concomitantly also stimulate the production of a battery of other inflammatory cytokines: IL-1, IL-6, IL-8, multiple CSFs, IFN, and TGF-beta. Moreover, TNF itself stimulates the production of most of these cytokines. Thus even when pure recombinant TNF is used, it readily generates the production of other interactive cytokines. This apparent redundancy in the production of cytokines with overlapping effects presumably has protective advantage for the host. Furthermore, interaction of these cytokines is more economical and amplifies the responses to subtoxic doses of potentially harmful cytokines. Cytokine interaction may lead to either synergistic (as for many TNF-IL-1 interactions) or antagonistic effects (TNF and TGF-beta, for example). These may depend on (1) the modulation of receptor expression of one cytokine by another (IFN-gamma-enhancing receptor expression for TNF, and TGF-beta down-regulation of IL-1 receptors), (2) stabilization of the cytokine message by one another (induction of IL-6 by TNF or IL-1), (3) interactions at the level of signal transduction, (4) gene expression, or (5) at the posttranslational level. Thus the receptor repertoire, which is a function of the cell type and stage of development, actually determines the net effects of a particular combination of interactive cytokines. Clearly, the mechanisms of these interactions will need to be elucidated to better understand their biological function and to permit cytokines to be used clinically to the advantage of the host.
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PMID:Relationship of TNF to interleukins. 155 Aug 74

The influence of cytokines on extracellular superoxide dismutase (EC-SOD) expression by human dermal fibroblasts was investigated. The expression was markedly stimulated by interferon-gamma (IFN-gamma), was varying between fibroblast lines stimulated or depressed by interleukin-1 alpha (IL-1 alpha), was intermediately depressed by tumor necrosis factor-alpha (TNF-alpha), and markedly depressed by transforming growth factor-beta (TGF-beta). TNF-alpha, however, enhanced the stimulation by a high dose of IFN-gamma, whereas TGF-beta markedly depressed the stimulations given by IFN-gamma and IL-1 alpha. The ratio between the maximal stimulation and depression observed was around 30-fold. The responses were generally slow and developed over periods of several days. There were no effects of IFN-alpha, IL-2, IL-3, IL-4, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor, human growth hormone, Escherichia coli lipopolysaccharide, leukotriene B4, prostaglandin E2, formylmethionylleucylphenylalanine, platelet-activating factor, and indomethacin. The cytokines influencing the EC-SOD expression are also known to influence superoxide production by leukocytes and other cell types, and the EC-SOD response pattern is roughly compatible with the notion that its function is to protect cells against extracellular superoxide radicals. The results show that EC-SOD is a participant in the complex inflammatory response orchestrated by cytokines. The CuZn-SOD activity of the fibroblasts was not influenced by any of the cytokines, whereas the Mn-SOD activity was depressed by TGF-beta. TNF-alpha, IL-1 alpha, and IFN-gamma stimulated the Mn-SOD activity, as previously known, and these responses were reduced by TGF-beta. The different responses of the three SOD isoenzymes illustrate their different physiological roles.
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PMID:Regulation by cytokines of extracellular superoxide dismutase and other superoxide dismutase isoenzymes in fibroblasts. 155 78

Both keratin synthesis and the formation of the horny layer are "classical" functions of human epidermal keratinocytes. In recent year a couple of interesting immunological functions of keratinocytes have been discovered. In the present review phagocytosis, production and secretion of cytokines (IL-1, IL-3, IL-6, IL-8, CSF, ECDF, IFN) and their ligands as well as the expression of selected cell surface receptors (HLA-DR, ICAM-1, Fc-gamma receptor) ligands are described.
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PMID:[The keratinocyte--a biologically active cell]. 169 21

The capacity of human melanocytes and melanoma cells to produce IL-8 and monocyte chemotactic and activating factor (MCAF) was investigated. Melanocytes expressed mRNA for IL-8 and MCAF, when stimulated with either IL-1 alpha or TNF alpha, but not when stimulated with IL-6, IFN gamma, or LPS alone. IL-8 and MCAF could be induced in a dose-dependent fashion with doses as low as 0.1 ng/ml TNF alpha and 0.5 ng/ml IL-1 alpha. IL-8 and MCAF mRNA were rapidly expressed and peaked between 2 and 4 h for IL-8 and between 4 and 8 h for MCAF. This correlated well with the accumulation of IL-8 antigen as measured by a radioimmunoassay. Supernatants from melanocyte cultures stimulated with either IL-1 alpha or TNF alpha and separated on a heparin-Sepharose column became positive for neutrophil and monocyte chemotactic activity in a dose- and time-dependent fashion. When IFN gamma was added to melanocyte cultures stimulated with suboptimal doses of TNF alpha there was a synergistic increase in secreted IL-8 protein and monocyte chemotactic activity. These data provide further evidence for the possible role of melanocytes in the initiation of an inflammatory reaction. Three different malignant melanoma cell lines stimulated with either TNF alpha or IL-1 alpha expressed IL-8 mRNA, but not mRNA for MCAF. The IL-8 mRNA signal corresponded well with the amount of secreted IL-8 protein. These data suggest that IL-8 and MCAF may play a role in growth regulation and spreading of melanomas.
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PMID:Expression and secretion of leukocyte chemotactic cytokines by normal human melanocytes and melanoma cells. 187 58


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