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Query: UNIPROT:P10145 (
IL-8
)
23,849
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We considered the role of two neutrophil chemotactic agents (interleukin-8 and leukotriene B4) and of
myeloperoxidase
(a neutrophil-associated enzyme) in the pathologic condition of Crohn's disease (CD). Serial biopsy samples were taken at different sites in the colon, washed in 0.02 M phosphate-saline buffer, homogenized, and then sonicated.
Interleukin-8
levels were significantly increased throughout the colonic mucosa (> 300 pg/mg protein) in patients with CD compared with control groups (< 40 pg/mg protein) (p < or = 0.01). A two- to six-fold increase in leukotriene B4 was also found in CD, whereas mucosal levels of
myeloperoxidase
were unchanged compared with control subjects. This study demonstrates that interleukin-8 and leukotriene B4 may have an immunologic role in the pathologic condition of CD.
...
PMID:Neutrophil-activating peptide (interleukin-8) in colonic mucosa from patients with Crohn's disease. 838 93
IL-8
belongs to the family of chemotactic cytokines and may play an important role in the inflammatory response. In the current studies, a murine mAb (DM/C7) to human rIL-8 was found to have protective effects in inflammatory lung injury in rats. DM/C7 was nonreactive with the rat cytokine-induced neutrophil chemoattractant peptide. In vivo, DM/C7 blocked the glycogen-induced accumulation of neutrophils in rats and was highly protective against lung and dermal vascular injury after deposition of IgG immune complexes. The latter model of injury has recently been shown to be E-selectin dependent. The protective effects of DM/C7 correlated with reduced tissue accumulation of neutrophils, as measured by
myeloperoxidase
content. DM/C7 reacted with an epitope expressed by TNF-alpha-stimulated rat pulmonary artery endothelial cells and with the pulmonary vascular endothelium after intrapulmonary deposition of IgG immune complexes. In the model of IgG immune complex-induced lung injury, the protective effects of DM/C7 were abolished by prior absorption of the antibody with human rIL-8. Polyclonal antibody to cytokine-induced neutrophil chemoattractant peptide failed to protect against IgG immune complex-induced vascular injury even though this antibody blocked the in vitro chemotactic activity of cytokine-induced neutrophil chemoattractant. In the model of rapidly developing lung injury due to systemic activation of C after infusion of cobra venom factor, DM/C7 was not protective. As well, in the neutrophil-independent model of IgA immune complex-induced lung injury, treatment with DM/C7 was not protective. These data indicate that in inflammatory lung injury that is linked to E-selectin-dependent recruitment of neutrophils in rats, antibody to human
IL-8
also blocks recruitment of neutrophils and thereby affords protection against lung injury. The data suggest the presence of an
IL-8
-like product in this model of lung injury.
...
PMID:Inhibition of lung inflammatory reactions in rats by an anti-human IL-8 antibody. 839 May 38
Interleukin-8
(
IL-8
), a monocyte-derived neutrophil chemotactic agent, has a potential role in the regulation of inflammatory responses. The specific receptor for
IL-8
has been identified and characterized on the surface of human neutrophils (Samanta, A. K., Oppenheim, J. J., and Matsushima, K. (1989) J. Exp. Med. 169, 1185-1189). The present study demonstrates that at least two sulfhydryl groups of this receptor from human neutrophils participate in the binding of
IL-8
. Incubation of neutrophils with sulfhydryl group-modifying reagents, N-ethylmaleimide and diazene dicarboxylic acid bis-N,N-dimethylamide (diamide), severely impaired the binding of 125I-
IL-8
to neutrophils. Treatment with 0.8 mM N-ethylmaleimide and 0.4 mM diamide inhibit binding of 125I-
IL-8
to the neutrophils by 62 and 60%, respectively. These inhibitory effects could be reversed by 84-87% by treatment with 2-4 mM dithiothreitol. The saturable amount of the ligand,
IL-8
, provided partial protection against the modifying reagents. N-Ethylmaleimide and diamide at a concentration of 0.4 mM reduced chemotactic migration of neutrophils in a Boyden chamber by 95 and 60%, respectively. At a concentration of 0.4 mM, N-ethylmaleimide reduced the
IL-8
-induced (10 micrograms/ml) release of
myeloperoxidase
by 50%. Under identical conditions, 0.4 mM diamide could reduce release of
myeloperoxidase
by 63%. Finally, N-ethylmaleimide severely affected the overall binding and total uptake of 125I-
IL-8
to the neutrophils at 37 degrees C, a condition required for receptor-mediated internalization of the ligand and recycling of the receptor to the surface of neutrophils. Nitro blue tetrazolium reduction test of the lipopolysaccharide-stimulated neutrophils indicates that compared to control general metabolic functions of thiol-modified cells were markedly retained. These data suggest that at least two conformationally vicinal free reactive sulfhydryl groups are located in the binding domain of the receptor in neutrophils which are essential for
IL-8
-mediated biological responses.
...
PMID:Modification of sulfhydryl groups of interleukin-8 (IL-8) receptor impairs binding of IL-8 and IL-8-mediated chemotactic response of human polymorphonuclear neutrophils. 845 90
We have investigated whether
IL-8
is present in airway secretions from patients with asthma and chronic obstructive pulmonary disease (COPD) to obtain information on its possible role in airway inflammation in obstructive airways disease. In the bronchoalveolar lavage fluid (BALF) from 11 clinically stable patients with asthma the levels of
IL-8
were increased compared to 10 healthy subjects (median: controls 21.5 pg/ml, asthma 244 pg/ml: p < 0.005). In the patients with asthma the levels of
IL-8
correlated with the percentage neutrophils in the BALF (r = 0.81; p < 0.001) and with a parameter of the permeability of the respiratory membrane, the quotient (alpha 2-macroglobulin in BALF)/(alpha 2-macroglobulin in serum) (r = 0.66; p < 0.025). In the sputum sol phase of 9 patients with symptomatic asthma the levels of
IL-8
were lower than in 9 patients with COPD (asthma: 6.4 ng/ml; COPD: 16.3 ng/ml; p < 0.02) and significantly correlated with those of neutrophilic
myeloperoxidase
(
MPO
; r = 0.85; p < 0.005). The increased levels of
IL-8
in the airway secretions from both patients with asthma and COPD may be markers of an ongoing inflammatory process, which is more pronounced in patients with COPD. In patients with asthma the strong correlation between the levels of
IL-8
and the percentage neutrophils and/or the levels of
MPO
points to a role of
IL-8
in the recruitment and activation of neutrophils in the airway lumen.
...
PMID:Interleukin-8 in airway inflammation in patients with asthma and chronic obstructive pulmonary disease. 856 94
Granulocyte colony-stimulating factor (G-CSF) was administered at a dose of 7.5 or 10 micrograms/kg s.c. once daily for 6d (days 1-6) to two groups consisting of eight and six healthy volunteers. The administration of G-CSF resulted in a rapid decrease in neutrophil counts and serum levels of the secondary granule protein, human neutrophil lipocalin (HNL) after 30 min, followed by a recovery and gradual increase within 180 min. The number of circulating neutrophils and plasma and serum levels of neutrophil secondary granule proteins were dramatically elevated on day 2 (1 d after the administration of G-CSF) and stayed so until day 7. The plasma levels of HNL and lactoferrin (LF) showed a biphasic pattern with peaks at day 2 and days 5-7, and remained highly elevated at day 12. The serum levels of HNL and LF increased rapidly (about 8-fold and 6-fold, respectively) on day 2 and stayed elevated until day 7, subsequently returning to baseline levels. At day 5, neutrophil release induced in vitro by f-MLP was significantly enhanced. The cellular contents of HNL and LF were reduced to about 50% of levels before G-CSF administration at day 5. The release of lactoferrin and HNL, but not of
myeloperoxidase
(
MPO
), was slightly enhanced after preincubation of isolated normal neutrophils with G-CSF in vitro, but no obvious release of these proteins was observed with G-CSF alone. The administration of G-CSF resulted in a dramatic increase in the alkaline phosphatase (AP) activity in the plasma membrane, with maximal activity occurring at day 5. Furthermore, during administration of G-CSF, TNF-alpha in plasma increased about 25-fold. TNF-alpha started to rise at day 2 and peaked at day 6. After discontinuation of G-CSF the levels of TNF-alpha gradually decreased. The elevated levels of TNF-alpha (tumour necrosis factor-alpha) were temporally correlated to the other signs of neutrophil activation. GM-CSF and
IL-8
, however, were not detected in plasma. Our data suggest that G-CSF affects the neutrophils not only directly but also indirectly by the induction of the production of other cytokines such as TNF-alpha.
...
PMID:The effect of granulocyte colony-stimulating factor (G-CSF) on the degranulation of secondary granule proteins from human neutrophils in vivo may be indirect. 865 73
New selenium-containing compounds behave as GPx mimics and protect endothelial cells (HUVEC) from damage upon exposure to 55 microM linoleic acid hydroperoxide or to 200 microM hydrogen peroxide. The simultaneous presence of the GPx mimic and the hydroperoxyde is not necessary, since a pre-treatment of endothelial monolayers with 1 to 10 microM of such compounds, preserves their morphology, their cell density and their longer-term viability. The compounds which are most efficient in this model of oxidative stress also protect endothelial monolayers which have been incubated with an excess (10:1) of polymorphonuclear neutrophils (PMN) and with 1 ng/ml of TNF-alpha, if such monolayers are pre- and co-treated (10 microM). They inhibit the adhesion of activated neutrophils which show-up as polymorphous and very dense particles, in the vicinity of which endothelial alterations can be seen. The inhibition of leucocyte adhesion and that of endothelial activation/alteration have been quantified by means of immunoassays of
myeloperoxidase
and von Willebrand factor (vWf). The lead-compound BXT-51072 is not a direct inhibitor of the NADPH oxidase of PMN. TNF-alpha alone induces the endothelial release of
Interleukin-8
(Il-8) as well as the expression of P- and E-selectin. The extent and the kinetics of inhibition of such processes by compound BXT-51072 would explain several of the effects observed in the presence of PMN. The GPx mimics also inhibit the endothelial production of Il-8 which is induced by Interleukin-1 alpha. Finally, compound BXT-51072 inhibits the endothelial expression of the adhesion factor VCAM-1 which is more slowly induced by TNF-alpha. Such antioxidant catalysts therefore protect endothelial cells from the toxic effects of TNF-alpha through mechanisms which include a down-regulation of cytokines and cell-adhesion factors.
...
PMID:[Antioxidant and anti-inflammatory protection of vascular endothelial cells by new synthetic mimics of glutathione peroxidase]. 867 32
Exposure of healthy subjects to ozone is associated with increases in cellular and biochemical markers of inflammation in bronchoalveolar lavage fluid. To determine if analysis of induced sputum might similarly reveal the pulmonary inflammatory effects of ozone exposure, we performed cellular and biochemical analysis of induced sputum collected 4 hr after air and ozone (0.4 ppm for 2 hr) exposures from 10 healthy subjects (age 30.0 +/- 5.0 years; 5 females) in a randomized crossover study in which exposures were separated by 2 weeks. We found that the total number of nonsquamous cells was significantly higher after ozone exposure than after air exposure (7.4 vs 3.9 x 10(5)/ml, P < 0.05) as was the percentage of the nonsquamous cells that were neutrophils (80.0 +/- 7.0% vs 51.0 +/- 20.0%, P < 0.05) and the levels of
myeloperoxidase
in the sputum fluid phase (1.6 +/- 0.6 vs 1.3 +/- 0.6 microg/ml, P < 0.05). In addition, IL-6 and
IL-8
levels were higher after ozone than after air exposures, but not significantly so (44.5 +/- 32.4 pg/ml vs 26.8 +/- 30.7 pg/ml, P = 0.11; 1.5 +/- 0.5 ng/ml vs 1.1 +/- 0.6 ng/ml, P = 0.09). Mucin-like glycoprotein levels were also not significantly different between exposures (1.6 +/- 0.9 mg/ml vs 1.3 +/- 1.0 mg/ml, P = 0.26). We conclude that analysis of induced sputum is a useful noninvasive method for studying the pulmonary response to ozone exposure in healthy subjects.
...
PMID:Analysis of induced sputum after air and ozone exposures in healthy subjects. 867 83
Within the gastroduodenal mucosa Helicobacter pylori infection stimulates local production of a range of proinflammatory and immunoregulatory cytokines, neutrophil infiltration, specific T- and B-cell responses and the development of gastric lymphoid follicles. Following bacterial eradication this mucosal inflammatory response resolves. Infiltrating neutrophils are likely to be one of the major mediators of mucosal damage. Neutrophil activation, including reactive oxygen metabolite production and the release of
myeloperoxidase
, will be induced directly by bacterial factors and indirectly through products of complement activation, bioactive lipids and host-derived cytokines.
Interleukin-8
, and related peptides of the chemokine family secreted by gastric epithelial cells, are likely to be important host mediators inducing neutrophil migration to sites of infection. Epithelial
IL-8
is upregulated by TNF-alpha and IL-1 and directly by H. pylori strains expressing the CagA phenotype. The extent of mucosal injury may reflect bacterial density, the variability of different strains of H. pylori to induce chemokine expression in epithelial cells and the oxidative burst in neutrophils. Recent evidence from in vivo and in vitro studies shows that CagA+ VacA+ strains of H. pylori are associated with enhanced inflammatory responses and mucosal damage. Defining the specific bacterial mediators of mucosal inflammation will be important in elucidating the role of H. pylori in the pathogenesis of gastroduodenal disease.
...
PMID:Gastric mucosal inflammatory responses to Helicobacter pylori. 873 Feb 57
A fusion protein was generated by genetic engineering which combined a Fab fragment of a monoclonal antibody directed to the human epidermal growth factor receptor with the biologically active N-terminally truncated 2-72 amino acid form of the human chemokine
IL-8
. The Fab
IL-8
fusion protein was expressed in E. coli and antibody binding and
IL-8
activity were determined. Our data indicate that the N-terminus of
IL-8
remains functional for receptor interaction. The fusion protein showed specific binding to
IL-8
receptors, induced
IL-8
mediated chemotactic activity, and the release of
MPO
activity. However, N-terminal fusion of
IL-8
to the carboxyl terminus of the Fab fragment resulted in reduced binding to
IL-8
receptors and consequently to reduced biologic activity of
IL-8
. The affinity of the antibody arm for EGF-R was improved when compared to a monovalent Fab. Fusion proteins as described herein may represent improved therapeutics for cancer therapy based on their potential to selectively increase and prolong cytokine concentration in the tumour. Since chemokines such as
IL-8
recruit effector cells and stimulate effector cell function in situ, a lymphocyte-independent anti-tumour activity followed by tumour-specific immunity could be proposed.
...
PMID:A fusion protein of IL-8 and a Fab antibody fragments binds to IL-8 receptors and induces neutrophil activation. 883 36
Although interleukin (IL)-8 is well known as a chemotactic agent for neutrophil migration in vitro, the relationship between
IL-8
activity and the degree of neutrophil infiltration in gastric mucosa is still unclear. In the present study, we investigated
IL-8
and
myeloperoxidase
activity, a marker of neutrophil infiltration, in gastric antral mucosa using biopsy samples in 23 patients with no gastric lesions. The results indicate that there is a good correlation between
IL-8
and
myeloperoxidase
activity (y = 0.173x + 13.9; r = 0.49, P < 0.01). Furthermore,
IL-8
and
myeloperoxidase
activity are significantly higher in Helicobacter pylori-positive patients than in H. pylori-negative patients. In conclusion, an increase of
IL-8
activity in the gastric mucosa causes increased neutrophil infiltration in human gastric mucosa and H. pylori infection accelerates these reactions in the mucosa.
...
PMID:Relationship between interleukin-8 levels and myeloperoxidase activity in human gastric mucosa. 908 10
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