In vitro inhibition of leukotriene B4 formation by exogeneous 5-lipoxygenase inhibitors is associated with enhanced generation of 15-hydroxy-eicosatetraenoic acid (15-HETE) by human neutrophils

1988 ◽  
Vol 280 (7) ◽  
pp. 430-436 ◽  
Author(s):  
K. Fogh ◽  
T. Herlin ◽  
K. Kragballe
Keyword(s):  
Leukotriene B4 ◽  
Eicosatetraenoic Acid ◽  
Human Neutrophils ◽  
Lipoxygenase Inhibitors ◽  
In Vitro Inhibition

scholarly journals Pneumolysin Potentiates Production of Prostaglandin E2 and Leukotriene B4 by Human Neutrophils

2001 ◽  
Vol 69 (5) ◽  
pp. 3494-3496 ◽  
Author(s):  
Riana Cockeran ◽  
Helen C. Steel ◽  
Timothy J. Mitchell ◽  
Charles Feldman ◽  
Ronald Anderson
Keyword(s):  
Prostaglandin E2 ◽  
Inflammatory Responses ◽  
Pneumococcal Infection ◽  
Leukotriene B4 ◽  
Human Neutrophils ◽  
Prostaglandin E ◽  
Calcium Dependent

ABSTRACT Exposure to pneumolysin (8.37 and 41.75 ng/ml) caused a calcium-dependent increase in the generation of prostaglandin E2 and leukotriene B4 by both resting and chemoattractant-activated human neutrophils in vitro. These interactions of pneumolysin with neutrophils may result in dysregulation of inflammatory responses during pneumococcal infection.

L-selectin function is required for beta 2-integrin-mediated neutrophil adhesion at physiological shear rates in vivo

1992 ◽  
Vol 263 (4) ◽  
pp. H1034-H1044 ◽  
Author(s):  
U. H. Von Andrian ◽  
P. Hansell ◽  
J. D. Chambers ◽  
E. M. Berger ◽  
I. Torres Filho ◽  
...  
Keyword(s):  
Neutrophil Function ◽  
Leukotriene B4 ◽  
Human Neutrophils ◽  
Neutrophil Adhesion ◽  
Shear Rates ◽  
Sequence Of Events ◽  
Multistep Process ◽  
Beta 2

In vivo interactions between neutrophils and endothelial cells (EC) follow a multistep process involving two distinct neutrophil adhesion receptors. L-selectin, constitutively functional on resting neutrophils, mediates an activation-independent primary interaction resulting in rolling along the venular wall. Subsequent activation of rolling neutrophils induces upregulation and functional activation of beta 2-integrins (CD11/CD18) leading to firm attachment. Based on previous findings we hypothesized that, under shear force, rolling may be essential for successful neutrophil-EC recognition. Here we report results of our studies of human neutrophil behavior in interleukin (IL)-1-activated rabbit mesentery venules, an interaction that requires both L-selectin and beta 2-integrins. Rolling of human neutrophils is L-selection mediated; it was strongly reduced by monoclonal antibody inhibition or enzymatic removal of L-selectin. Furthermore, activation induced L-selectin shedding and, in a dose- and time-dependent fashion, rendered neutrophils unable to recognize inflamed EC despite expression of active beta 2-integrins, which promoted adhesion in vitro. Neutrophils activated for 5 min or longer lost most of their ability to roll. However, 1-3 min after activation, rolling was reduced (not abolished), and cells that were still able to roll displayed a significant tendency for a CD18-dependent transition from rolling to sticking. The whole sequence of events, rolling, sticking, and transendothelial migration, could be observed if an extravascular chemotactic stimulus was applied by superfusing mesenteries with leukotriene B4. Under such conditions, sticking and emigration was blocked when rolling was inhibited by enzymatic removal of L-selectin. Our results indicate that primary neutrophil interaction with inflamed EC through the L-selectin is a prerequisite for neutrophil function at physiological shear rates in vivo.

scholarly journals Identification and characterization of specific receptors for monocyte-derived neutrophil chemotactic factor (MDNCF) on human neutrophils.

1989 ◽  
Vol 169 (3) ◽  
pp. 1185-1189 ◽  
Author(s):  
A K Samanta ◽  
J J Oppenheim ◽  
K Matsushima
Keyword(s):  
Human Peripheral Blood ◽  
Platelet Activating Factor ◽  
Leukotriene B4 ◽  
Chemotactic Factor ◽  
Single Type ◽  
Human Neutrophils ◽  
Scatchard Analysis ◽  
Specific Receptors ◽  
Neutrophil Chemotactic Factor

Specific receptors for a recently purified and cloned monocyte-derived neutrophil chemotactic factor (MDNCF) have been identified on the surface of normal human peripheral blood neutrophils using 125I-labeled recombinant human MDNCF (125I-MDNCF). Competitive binding of 125I-MDNCF to human neutrophils reached a maximal level at 1-3 h at 4 degrees C. The Scatchard analysis showed that there are approximately 20,000 receptors per cell with a single type of high affinity binding (Kd, 8 x 10(-10) M). The receptors for MDNCF are clearly distinct from the receptors for other cytokines and chemotactic agents, e.g., IL-1 alpha, TNF-alpha, and FMLP, C5a, leukotriene B4, and platelet activating factor. Based on the SDS-PAGE analysis of chemically crosslinked 125I-MDNCF receptor complex, there are two polypeptides that bind MDNCF; the molecular weight of these two MDNCF receptors were estimated to be 67,000 and 59,000. Treatment of a promyelocytic cell line, HL60, with 1.25% DMSO for 5 d in vitro increased the number of receptors up to 7,000 receptors/cell with a Kd of 1.2 x 10(-9) M.

scholarly journals Functional characterization of synthetic leukotriene B and its stereochemical isomers.

1981 ◽  
Vol 154 (4) ◽  
pp. 1243-1248 ◽  
Author(s):  
R A Lewis ◽  
E J Goetzl ◽  
J M Drazen ◽  
N A Soter ◽  
K F Austen ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Neutrophil Infiltration ◽  
Eicosatetraenoic Acid ◽  
Human Neutrophils ◽  
Racemic Mixture ◽  
Hydroxyl Groups ◽  
Biological Assays ◽  
Neutrophil Chemotactic Activity

Leukotriene B (LTB), a potent lipid chemotactic factor for neutrophils, is 5S,12R-dihydroxy-6,14-cis,8,10-trans-eicosatetraenoic acid (Fig 1), based upon direct comparison of natural LTB with synthetic 5S,12R-dihydroxy-6,8,10,14-eicosatetraenoic acid (5,12-di-HETE) stereoisomers in three biological assays. Of the six synthetic stereoisomers evaluated, only the 5S,12R,6,14-cis,8,10-trans compound had chemotactic potency for human neutrophils in vitro that was comparable to that of natural LTB, with a concentration of 3 X 10(9-9) M eliciting a one-half maximum response. In contrast, the racemic mixture of 5R,12R- and 5S,12S-6,10-trans,8,14-cis, the racemic mixture of 5S,12R- and 5R,12S-6,10-trans,8,14-cis, the 5S,12R-6,8-trans,10,14-cis, the 5S,12R-6,8,10-trans,14-cis, and the 5S,12S-6,8,10-trans,14-cis stereoisomers required concentrations of 3 X 10(-7) to 1 X 10(-6) M to elicit comparable responses. Only natural LTB and its synthetic counterpart elicited a local neutrophil infiltration when injected into the skin of the rhesus monkey at 10 ng and 100 ng per site. Natural and synthetic LTB at a concentration of 3 X 10(-8) M each provoked an EC25 contractile response of guinea pig pulmonary parenchymal strips in vitro, whereas the other four tested stereoisomers of 5,12-di-HETE were inactive at this concentration. Structure-function analyses suggest that the neutrophil chemotactic activity depends critically upon the C-1 to C-12 domain, including the stereochemistry of the 6-,8-,and 10-olefinic bonds and the presence of both hydroxyl groups.

scholarly journals Leukotriene B4 Augments Neutrophil Phagocytosis of Klebsiella pneumoniae

2001 ◽  
Vol 69 (4) ◽  
pp. 2011-2016 ◽  
Author(s):  
Peter Mancuso ◽  
Patrick Nana-Sinkam ◽  
Marc Peters-Golden
Keyword(s):  
Klebsiella Pneumoniae ◽  
Human Peripheral Blood ◽  
Critical Role ◽  
Leukotriene B4 ◽  
Eicosatetraenoic Acid ◽  
Human Neutrophils ◽  
Complement Receptor ◽  
Macrophage Phagocytosis ◽  
Blood Neutrophils ◽  
Cysteinyl Leukotriene Receptor

ABSTRACT Neutrophils play a critical role in the clearance of bacteria from the lung and other organs by their capacity for phagocytosis and killing. Previously, we identified an important role for the leukotrienes in rat alveolar macrophage phagocytosis ofKlebsiella pneumoniae. In this report, we explored the possibility that the leukotrienes play an important role in phagocytosis by neutrophils as well. Inhibition of endogenous leukotriene synthesis by 5-lipoxygenase knockout in mice or by pharmacologic means in human peripheral blood neutrophils attenuated phagocytosis of opsonized K. pneumoniae. Reduced phagocytosis was also observed in human neutrophils pretreated with a leukotriene B4 receptor but not a cysteinyl-leukotriene receptor antagonist. While leukotriene B4 reconstituted defective phagocytosis in leukotriene-deficient neutrophils and enhanced phagocytosis in neutrophils capable of leukotriene synthesis, leukotriene C4, leukotriene D4, 5-hydroperoxyeicosatetraenoic acid, and 5-oxo-eicosatetraenoic acid were ineffective. To determine the opsonin dependence of the leukotriene B4 augmentation of phagocytosis, we assessed the ability of leukotriene B4 to modulate neutrophil phagocytosis and the adherence of sheep erythrocytes opsonized with immunoglobulin G or the complement fragment C3bi. While leukotriene B4 augmented both Fc receptor- and complement receptor-mediated phagocytosis, increased adherence to leukotriene B4-treated neutrophils was limited to complement opsonized targets. In conclusion, we have identified a novel role for leukotriene B4 in the augmentation of neutrophil phagocytosis mediated by either the Fc or complement receptor.

Prevalence of 5-Lipoxygenase Expression in Canine Osteosarcoma and the Effects of a Dual 5-Lipoxygenase/Cyclooxygenase Inhibitor on Osteosarcoma Cells In Vitro and In Vivo

2012 ◽  
Vol 49 (5) ◽  
pp. 802-810 ◽  
Author(s):  
R. C. Goupil ◽  
J. J. Bushey ◽  
J. Peters-Kennedy ◽  
J. J. Wakshlag
Keyword(s):  
Cell Proliferation ◽  
Xenograft Model ◽  
Eicosatetraenoic Acid ◽  
Treatment Modalities ◽  
Nuclear Staining ◽  
Lipoxygenase Inhibitors ◽  
Canine Osteosarcoma ◽  
Area Of Interest

Canine osteosarcoma is an insidious disease with few effective treatment modalities; therefore, use of pharmacologic intervention to improve mortality or morbidity is constantly sought. The use of cyclooxygenase enzyme inhibitors has been an area of interest with limited efficacy based on retrospective examination of tumor expression and in vivo cell proliferation models. Recently, examination of dual cyclooxygenase and 5-lipoxygenase inhibitors in human and canine oncology suggests that 5-lipoxygenase inhibitors may be an effective approach in vitro and during tumor induction in rodent models. Therefore, the authors decided to examine 5-lipoxygenase expression in primary canine osteosarcoma samples and have shown that approximately 65% of osteosarcomas label positive for cytoplasmic 5-lipoxygenase. Further examination of a cell culture and xenograft model shows similar 5-lipoxygenase expression. Surprisingly, a canine 5-lipoxygenase inhibitor (tepoxalin) significantly reduced cell proliferation at physiologic doses in vitro and diminished xenograft tumor growth in nude mice, suggesting that further investigation is needed. Traditionally, 5-lipoxygense leads to production of lipid mediators, such as leukotriene B4 and 5-oxo-eicosatetraenoic acid, which, when added back to the media of tepoxalin-treated cells, did not recover cell proliferation. The lack of nuclear staining in primary and xenografted tumors and the lack of response to eicoasanoids suggest that lipid mediator production is not the primary means by which tepoxalin acts to alter proliferation. Regardless of the mechanisms involved in retarding cell proliferation, future investigation is warranted.

Proinflammatory mediators elicit secretion of the intracellular B-lymphocyte stimulator pool (BLyS) that is stored in activated neutrophils: implications for inflammatory diseases

Blood ◽  
2005 ◽  
Vol 105 (2) ◽  
pp. 830-837 ◽  
Author(s):  
Patrizia Scapini ◽  
Antonio Carletto ◽  
Bernardetta Nardelli ◽  
Federica Calzetti ◽  
Viktor Roschke ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
B Lymphocyte ◽  
De Novo ◽  
Inflammatory Responses ◽  
Leukotriene B4 ◽  
Human Neutrophils ◽  
Immunogold Electron Microscopy ◽  
Proinflammatory Mediators ◽  
B Lymphocyte Stimulator

Abstract We have recently shown that granulocyte–colony-stimulating factor (G-CSF)– and interferon-γ (IFN-γ)–activated human neutrophils accumulate and release remarkable amounts of soluble B-lymphocyte stimulator (BLyS) in vitro. In this study, we provide evidence that neutrophils migrating into skin window exudates (SWEs) developed in healthy volunteers and in patients with rheumatoid arthritis (RA), synthesized, and released BLyS in response to locally produced G-CSF. Accordingly, the concentrations of soluble BLyS in SWEs were significantly more elevated than in serum. Because the levels of SWE BLyS, but not SWE G-CSF, were higher in patients with RA than in healthy subjects, we examined the effect of CXCL8/IL-8, C5a, and other proinflammatory mediators that dramatically accumulate in RA SWEs and in inflamed synovial fluids. We show that CXCL1/GROα, CXCL8/IL-8, C5a, immune complexes, tumor necrosis factor-α (TNF-α), leukotriene B4, N-formyl-methionyl-leucyl-phenylalanine (fMLP), and lipopolysaccharide (LPS), which by themselves do not induce BLyS de novo synthesis, act as potent secretagogues for BLyS, which is mainly stored in Golgi-related compartments within G-CSF–treated neutrophils, as determined by immunogold electron microscopy. This action is pivotal in greatly amplifying neutrophil-dependent BLyS release in SWEs of patients with RA compared with healthy subjects. Collectively, our data uncover a novel mechanism that might dramatically exacerbate the release of BLyS by neutrophils during pathologic inflammatory responses.

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