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)

In a previous study we observed that neutrophils respond with a rapid rise in [Ca2+]i during adherence to cytokine-activated endothelial cells (EC), caused by EC membrane-associated platelet-activating factor (PAF). In the present study, we investigated whether this form of PAF was important in neutrophil adherence and migration across monolayers of rIL-1 beta- or rTNF alpha-prestimulated EC. PAF receptor antagonists prevented neutrophil migration across cytokine-pretreated EC by approximately 60% (P less than 0.005) without interfering with the process of adherence. The antagonists WEB 2086 and L-652,731 had no effect on neutrophil migration across resting EC induced by formylmethionyl-leucyl-phenylalanine (FMLP). A murine anti-IL-8 antiserum was found to also partially inhibit the neutrophil transmigration across cytokine-activated EC. When the anti-IL-8 antiserum was used in combination with a PAF receptor antagonist, neutrophil migration across cytokine-pretreated monolayers of EC was completely prevented. During transmigration, LAM-1 and CD44 on the neutrophils were down-modulated; both WEB 2086 and anti-IL-8 antiserum partially prevented this down-modulation caused by cytokine-prestimulated EC. Our results indicate that human neutrophils are activated and guided by EC-associated PAF and EC-derived IL-8 during the in vitro diapedesis in between cytokine-stimulated EC.
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PMID:Neutrophil migration across monolayers of cytokine-prestimulated endothelial cells: a role for platelet-activating factor and IL-8. 131 17

Several structural homologues of the chemotactic peptide neutrophil-activating peptide 1/IL-8 (NAP-1/IL-8) were tested for their ability to influence the expression and function of adhesion-promoting receptors on human polymorphonuclear leukocytes (PMN). NAP-2, melanoma growth stimulatory activity, and two forms of NAP-1/IL-8 (ser-NAP-1/IL-8 and ala-NAP-1/IL-8, consisting of 72 and 77 amino acids, respectively), each caused an increase in the expression of CD11b/CD18 (CR3) and CR1, which was accompanied by a decrease in the expression of leukocyte adhesion molecule-1 (LAM-1, LECAM-1). The binding activity of CD11b/CD18 was also enhanced 3- to 10-fold by these peptides, but enhanced function was transient: binding of erythrocytes coated with C3bi reached a maximum by 30 min and declined thereafter. Ser-NAP-1/IL-8, ala-NAP-1/IL-8, NAP-2, and melanoma growth stimulatory activity also caused a two- to threefold enhancement of the phagocytosis of IgG-coated erythrocytes (EIgG) by PMN without causing a large increase in the expression of Fc gamma receptors. Enhanced phagocytosis of EIgG appeared to be mediated through CD11b/CD18, because F(ab')2 fragments of an antibody directed against CD18 inhibited NAP-1/IL-8-stimulated ingestion of EIgG. The four active peptides caused a rapid, transient increase in the amount of F-actin within PMN, indicating that they are capable of influencing the structure of the microfilamentous cytoskeleton, which participates in phagocytosis. Two other NAP-1/IL-8-related peptides, platelet factor 4 and connective tissue-activating peptide III, were without effect on expression of CD11b/CD18, CR1, and LAM-1, binding activity of CD11b/CD18, or Fc-mediated phagocytosis, and increased actin polymerization only slightly. Our observations indicate that several members of the NAP-1/IL-8 family of peptides were capable of promoting integrin-mediated adhesion and Fc-mediated phagocytosis, processes important in the recruitment of PMN to sites of inflammation and antimicrobial responses of PMN.
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PMID:Differential effects of neutrophil-activating peptide 1/IL-8 and its homologues on leukocyte adhesion and phagocytosis. 172 41

Injection (i.v.) of the granulocyte chemoattractant/activator IL-8 has been shown to reduce neutrophil recruitment into dermal inflammatory sites in vivo. To further investigate the mechanism of this phenomenon, we examined the effect of i.v. [Ser-IL-8]72 (12-20 micrograms/kg) on leukocyte rolling and chemoattractant-induced emigration in mesenteric venules of New Zealand White rabbits and on expression of L-selectin (mAb LAM1-3) and CD18 (mAb 60.3) on circulating rabbit granulocytes. Within 1 min of IL-8 i.v., granulocytes virtually disappeared from carotid blood samples for approximately 5 min. Concomitantly, the flux of rolling leukocytes in mesenteric venules fell from 83 +/- 21 to 2 +/- 1 leukocytes/min. Both rolling leukocyte flux and systemic granulocyte count returned to or exceeded control values within less than 30 min. The chemoattractant/activator FMLP (0.15 microgram/kg i.v.) produced similar results. A second i.v. injection of IL-8 or FMLP, 90 min after the first challenge, had equipotent effects. Local extravascular application of IL-8 via micropipette close to a venule induced adhesion and emigration of 63 +/- 21 leukocytes per site before, but only 26 +/- 9 leukocytes per site 50 to 75 min after i.v. IL-8, when systemic granulocyte count and rolling leukocyte flux had reached or exceeded control values. This was not due to agonist-specific desensitization, because a similar reduction of leukocyte emigration was seen after FMLP i.v. Rabbit granulocytes circulating in vivo uniformly expressed near-control levels of L-selectin at all times between 3 and 360 min after IL-8 i.v. CD18 expression transiently increased after IL-8 i.v. and returned to base line by 90 min. These findings show that IL-8 i.v. reduces granulocyte recruitment to inflammatory sites by inhibiting function(s) necessary for transmigration that are independent of L-selectin and subsequent to rolling.
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PMID:Intravenous interleukin-8 inhibits granulocyte emigration from rabbit mesenteric venules without altering L-selectin expression or leukocyte rolling. 750 19

Pregnancy exerts suppressive effects on a number of chronic inflammatory conditions, particularly rheumatoid arthritis. We isolated peripheral blood polymorphonuclear leukocytes (PMN) from pregnant women at 30 to 34 wk (n = 34) and showed significant reductions in respiratory burst activity compared with nonpregnant controls (n = 34), as determined by lucigenin-enhanced chemiluminescence (LUCL). Responses to FMLP were reduced by 54% (p = 0.0046) and to zymosan-activated serum (ZAS) by 69% (p = 0.0043). Following LUCL responses to these agonists in women throughout the course of their pregnancy (n = 7) revealed significantly reduced responses by the second and third trimesters (p < 0.005). Intracellular H2O2 production in PMN at 30 to 34 wk gestation was significantly reduced (p = 0.0454) in response to FMLP, compared with the nonpregnant controls. Investigation of adhesion molecule expression revealed no differences in CD11b or CD18. However, loss of CD62L from the PMN surface in response to FMLP and ZAS was significantly reduced at 30 to 34 wk, as compared with controls (FMLP, p = 0.049; ZAS, p = 0.01; n = 34). There were no significant differences in cell surface formyl peptide receptor expression, although there were statistical differences in LUCL responses to all concentrations of FMLP used (p < 0.05). Incubating PMN with TNF, IL-8, and granulocyte-macrophage CSF increased formyl peptide receptor expression but revealed no differences between the two groups. Priming of pregnancy PMN with the same cytokines gave significantly reduced LUCL when cells were subsequently stimulated with FMLP (p < 0.05; n = 6). Our results show a reduction in PMN NADPH-oxidase activity during pregnancy and may offer a partial explanation for the remission of symptoms observed in rheumatoid arthritis.
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PMID:The effect of pregnancy on polymorphonuclear leukocyte function. 759 61

Over a period of 14 days a longitudinal analysis was performed on the effects of filgrastim (recombinant human granulocyte colony stimulating factor, rhG-CSF) administered to 20 postoperative/posttraumatic patients at risk of or with sepsis. The following parameters were determined: leukocyte counts, serum cytokine levels and the surface expression of functional antigens and adhesion molecules. Filgrastim (1 mu g/kg.day) was infused continuously on the first 3 days and tapered to 0.5 mu g/kg.day on the following 4 days or until discharge from the surgical intensive care unit. During infusion of filgrastim, G-CSF levels increased in 16 out of the 20 patients within 48 h. In these 16 patients, leukocyte counts increased in 15 out of 16 patients. Expression of CD64 was upregulated within 24 h. The expression of CD32 was upregulated in 8 out of 9 patients with an initial expression < 55%. LAM-1 expression was downregulated in all patients revealing an initial expression of LAM-1 > 40%. Soluble ICAM increased in 9 out of 11 patients. IL-8 decreased in all 6 patients presenting initial values of IL-8 > 90 pg/ml. IL-1RA increased in 10 patients. Filgrastim had no effect on the expression of CD14, CD16 and CD34 and on the levels of TNF-alpha and sTNF-R type I (p55). In conclusion, infusion of filgrastim in postoperative/post traumatic patients at risk of and with sepsis resulted in improved generation and function of neutrophils and appeared to counterregulate hyperactivation of proinflammatory processes.
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PMID:Filgrastim (RHG-CSF) related modulation of the inflammatory response in patients at risk of sepsis or with sepsis. 883 41

Neutrophil emigration through endothelial cells under shear flow involves several adhesion processes including cell rolling, arrest, and transmigration. Rolling is mediated by selectins, while arrest and transmigration both require activated CD18 integrins. One mode of CD18 activation is via selectins expressed on neutrophils and endothelial cells. We have recently reported that cross-linking of L-selectin (CD62L) resulted in the rapid activation of CD18-dependent adhesion. In the current study, we examine whether binding of E-selectin (CD62E) and L-selectin can activate neutrophil CD18-dependent adhesion under shear flow. Human ICAM-1 (CD54) and E-selectin were co-transfected into L cells. Neutrophil capture, rolling, and arrest on these monolayers were quantitated in a parallel plate flow chamber at a wall shear stress of 2.0 dyne/cm2. Under these conditions, E-selectin supported cell capture and rolling on the monolayer, but did not trigger CD18-mediated cell arrest within 200 microm of rolling. However, when neutrophils were treated with anti-L-selectin mAb and cross-linked with a secondary mAb, approximately 50% of the cells arrested within 54 microm. Cell arrest was also observed in response to IL-8 stimulation. A subthreshold level of IL-8 in combination with L-selectin cross-linking potentiated the level of cell arrest due to either stimulus alone. The transition to cell arrest involved both LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18). Blocking either subunit alone failed to reduce arrest, while blocking both molecules with mAbs reduced the number to baseline levels. These data support the conclusion that L-selectin, but not E-selectin, can signal the transition from neutrophil rolling to cell arrest under shear flow.
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PMID:Neutrophil CD18-dependent arrest on intercellular adhesion molecule 1 (ICAM-1) in shear flow can be activated through L-selectin. 897 12

Current models of the multistep adhesion cascade for leukocyte-endothelial interactions predict loss of L-selectin from the leukocyte surface before transendothelial migration. We have tested this hypothesis using in vitro adhesion and transendothelial migration assays and a zinc-dependent metalloproteinase inhibitor, Ro 31-9790 (N-2-((2s)-[(hydroxycarbamoyl)methyl)-4-methylvaleryl]-N-1,3 -dimethyl-L-valinamide), which prevents chemoattractant-induced (e.g., IL-8, FMLP, C5a, platelet-activating factor) L-selectin endoproteolytic cleavage from isolated human neutrophils. Inhibitor and vehicle-treated neutrophils exhibited identical behavior during both adhesive interactions with 4- and 24-h TNF-alpha-activated HUVEC monolayers under flow, (including rate of initial attachment, rolling velocities, stable adhesion, and transmigration) and in static adhesion assays. Flow cytometric analysis of transmigrated neutrophils with mAb to L-selectin revealed that vehicle treated neutrophils had minimal detectable surface L-selectin, whereas inhibitor-treated neutrophils retained comparable levels of L-selectin on their surface as neutrophils maintained at 37 degrees C. In addition, mAb to L-selectin that induce rapid shape change and homotypic adhesion (LAM1-116) did not enhance the rate or extent of neutrophil transmigration under flow or static conditions. Neutrophils preincubated with LAM 1-116 displayed similar behavior to neutrophils preincubated with the control anti-L-selectin mAb, LAM1-101. In summary, these results demonstrate that there is no requirement for L-selectin to be shed from the surface of neutrophils before, or during, their migration across endothelial monolayers, and that prevention of surface L-selectin proteolytic cleavage does not enhance or inhibit neutrophil-endothelial cell adhesive interactions.
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PMID:L-selectin shedding does not regulate human neutrophil attachment, rolling, or transmigration across human vascular endothelium in vitro. 912

There is increasing interest in the role of blood polymorphonuclear leukocytes (PMNs) in the pathogenesis of sickle cell crisis. We studied the adherence of PMNs from 18 sickle cell patients in crisis, 25 out of crisis, and 43 healthy subjects (controls) to monolayers of human umbilical cord endothelium that were either untreated or pretreated with tumor necrosis factor alpha (TNFalpha). Overall, the PMNs from patients in crisis were more adherent than control PMNs to untreated endothelial monolayers (mean 53% increase; P < .001) and TNFalpha-treated monolayers (mean 41% increase; P < .002). Increased adhesiveness was not associated with an abnormal expression of CD11a, CD11b, CD11c, CD18, CD62L, or CD15. There was an increase in the number of PMNs expressing CD64 in patients in crisis (median value, 44%) compared with patients out of crisis (median, 21%; P = .025) and controls (median, 6.5%; P < .001). Sera from patients in crisis had normal levels of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interferon-gamma, TNFalpha, interleukin-1 (IL-1), IL-6, or IL-8 and did not modify the adherence of PMNs or their expression of CD64. Only IFN-gamma induced CD64 expression on PMNs, but this effect was not associated with enhanced binding to endothelium. Because PMNs bound to endothelial monolayers were CD64(+) and CD64-enriched PMNs were 7 times more adherent to endothelial monolayers than CD64-depleted PMNs, it is likely that CD64 is a marker of adherent PMNs. Two of the three anti-CD64 antibodies used in our antibody blocking studies (clones 32.2 and 197) partially inhibited the binding of sickle cell PMNs to untreated endothelium (mean inhibitions of 33% [P = .01] and 21% [P = .03], respectively), whereas only one (clone 197) inhibited binding to TNFalpha-treated endothelium (mean inhibition, 29%; P = . 004). In some patients with sickle cell disease, an enhanced PMN adhesion to vascular endothelium could contribute to the vascular occlusion that characterizes the acute crisis of the disease.
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PMID:Blood polymorphonuclear leukocytes from the majority of sickle cell patients in the crisis phase of the disease show enhanced adhesion to vascular endothelium and increased expression of CD64. 941 94

Adhesion molecules are responsible for leukocyte recruitment in injured tissues. Here, the kinetics of expression and shedding of endothelial (sE-selectin-1, sP-selectin, and sICAM-1) and neutrophil (CD11b, CD62L, and CD54) adhesion molecules was investigated by serial determinations of serum concentrations in 20 patients with elective hip arthroplasty as an exemplary condition of acute inflammation in humans. Changes were related to secretion of proinflammatory cytokines (IL-1beta, IL-6, IL-8, and TNF-alpha) as their possible inducing signals. sE-selectin-1 responded to injury with a significant increase in concentrations already after 20 min, followed by sP-selectin and sICAM-1, which increased at Hour 10 and Day 1. Expression of CD11b and CD62L acutely responded to injury (within 1 h) by a parallel increase and decrease, respectively, and normalized by Day 1. Increases in concentrations of IL-1beta and TNF-alpha preceded the increase in adhesion molecules and significantly correlated with the response of sE-selectin-1 and sICAM-1. In conclusion, the close associations between release of IL-1beta and TNF-alpha and sE-selectin and sICAM-1 shown in this kinetic study indicates a key role of these cytokines in upregulation of endothelial rather than neutrophil adhesion molecules in vivo.
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PMID:Adhesion molecules in tissue injury: kinetics of expression and shedding and association with cytokine release in humans. 975 24

Crohn's disease (CD) lesions are characterized by a marked neutrophilic infiltrate associated with enhanced mucosal IL-8, contrasting with low serum IL-8 levels. The aim of this study was to investigate the effects of circulating GROalpha and IL-8 on neutrophil priming and migration. The expression of surface molecules involved in rolling (CD62L, CD15) and firm adhesion (Mac-1 and LFA-1) to endothelial cells was assessed by flow cytometry, while the chemotactic response of PMN to IL-8 and to fMLP was investigated in a Boyden chamber assay. In addition, IL-8 and GROalpha levels were determined by ELISA in plasma samples and in culture supernatants of purified polymorphonuclear neutrophils (PMN) and peripheral blood mononuclear cells (PBMC) from patients with CD and healthy blood donors. This study revealed an upregulation of CD11b (Mac-1) membrane expression on circulating PMN from patients with CD, as assessed by the mean fluorescence intensity which reflects antigen density. Furthermore, an enhanced chemotactic response towards both fMLP and IL-8 of PMN from CD patients was observed. Despite often undetectable levels of circulating IL-8, all plasma samples were positive for GROalpha, with a significant increase in CD patients when compared to donors. In vitro, equivalent concentrations of GROalpha were able to increase the IL-8 driven chemotaxis of PMN. In conclusion, blood PMN from patients with CD showed an enhanced capacity to be recruited into inflammed intestinal mucosa, which could be due to an increased expression of CD11b (Mac-1) as well as an increased chemotactic response toward fMLP or IL-8. This priming effect of PMN in CD may partly occur through elevated circulating GROalpha levels.
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PMID:Circulating growth-regulator oncogene alpha contributes to neutrophil priming and interleukin-8-directed mucosal recruitment into chronic lesions of patients with Crohn's disease. 988 9


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