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.

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.

scholarly journals A sand fly salivary protein acts as a neutrophil chemoattractant

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anderson B. Guimaraes-Costa ◽  
John P. Shannon ◽  
Ingrid Waclawiak ◽  
Jullyanna Oliveira ◽  
Claudio Meneses ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Calcium Influx ◽  
Parasite Burden ◽  
Salivary Protein ◽  
Sand Fly ◽  
Human Neutrophils ◽  
Chemotactic Protein ◽  
The Impact

AbstractApart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.

scholarly journals Electrospun Polydioxanone Loaded With Chloroquine Modulates Template-Induced NET Release and Inflammatory Responses From Human Neutrophils

2021 ◽  
Vol 9 ◽  
Author(s):  
Allison E. Fetz ◽  
Shannon E. Wallace ◽  
Gary L. Bowlin
Keyword(s):  
Growth Factor ◽  
Inflammatory Responses ◽  
Human Peripheral Blood ◽  
Early Time ◽  
Human Neutrophils ◽  
Late Time ◽  
Dependent Manner ◽  
Blood Neutrophils ◽  
Net Release

The implantation of a biomaterial quickly initiates a tissue repair program initially characterized by a neutrophil influx. During the acute inflammatory response, neutrophils release neutrophil extracellular traps (NETs) and secrete soluble signals to modulate the tissue environment. In this work, we evaluated chloroquine diphosphate, an antimalarial with immunomodulatory and antithrombotic effects, as an electrospun biomaterial additive to regulate neutrophil-mediated inflammation. Electrospinning of polydioxanone was optimized for rapid chloroquine elution within 1 h, and acute neutrophil-biomaterial interactions were evaluated in vitro with fresh human peripheral blood neutrophils at 3 and 6 h before quantifying the release of NETs and secretion of inflammatory and regenerative factors. Our results indicate that chloroquine suppresses NET release in a biomaterial surface area–dependent manner at the early time point, whereas it modulates signal secretion at both early and late time points. More specifically, chloroquine elution down-regulates interleukin 8 (IL-8) and matrix metalloproteinase nine secretion while up-regulating hepatocyte growth factor, vascular endothelial growth factor A, and IL-22 secretion, suggesting a potential shift toward a resolving neutrophil phenotype. Our novel repurposing of chloroquine as a biomaterial additive may therefore have synergistic, immunomodulatory effects that are advantageous for biomaterial-guided in situ tissue regeneration applications.

scholarly journals Tulathromycin Exerts Proresolving Effects in Bovine Neutrophils by Inhibiting Phospholipases and Altering Leukotriene B4, Prostaglandin E2, and Lipoxin A4Production

2014 ◽  
Vol 58 (8) ◽  
pp. 4298-4307 ◽  
Author(s):  
Carrie D. Fischer ◽  
Stephanie C. Duquette ◽  
Bernard S. Renaux ◽  
Troy D. Feener ◽  
Douglas W. Morck ◽  
...  
Keyword(s):  
Calcium Ionophore ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Lipid Signaling ◽  
Prostaglandin E ◽  
Ionophore A23187 ◽  
Proinflammatory Mediators ◽  
Bovine Neutrophils

ABSTRACTThe accumulation of neutrophils and proinflammatory mediators, such as leukotriene B4(LTB4), is a classic marker of inflammatory disease. The clearance of apoptotic neutrophils, inhibition of proinflammatory signaling, and production of proresolving lipids (including lipoxins, such as lipoxin A4[LXA4]) are imperative for resolving inflammation. Tulathromycin (TUL), a macrolide used to treat bovine respiratory disease, confers immunomodulatory benefits via mechanisms that remain unclear. We recently reported the anti-inflammatory properties of TUL in bovine phagocytesin vitroand inMannheimia haemolytica-challenged calves. The findings demonstrated that this system offers a powerful model for investigating novel mechanisms of pharmacological immunomodulation. In the present study, we examined the effects of TUL in a nonbacterial model of pulmonary inflammationin vivoand characterized its effects on lipid signaling. In bronchoalveolar lavage (BAL) fluid samples from calves challenged with zymosan particles (50 mg), treatment with TUL (2.5 mg/kg of body weight) significantly reduced pulmonary levels of LTB4and prostaglandin E2(PGE2). In calcium ionophore (A23187)-stimulated bovine neutrophils, TUL inhibited phospholipase D (PLD), cytosolic phospholipase A2(PLA2) activity, and the release of LTB4. In contrast, TUL promoted the secretion of LXA4in resting and A23187-stimulated neutrophils, while levels of its precursor, 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE], were significantly lower. These findings indicate that TUL directly modulates lipid signaling by inhibiting the production of proinflammatory eicosanoids and promoting the production of proresolving lipoxins.

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 Soluble iron modulates iron oxide particle-induced inflammatory responses via prostaglandin E2 synthesis: In vitro and in vivo studies

2009 ◽  
Vol 6 (1) ◽  
pp. 34 ◽  
Author(s):  
Ingrid Beck-Speier ◽  
Wolfgang G Kreyling ◽  
Konrad L Maier ◽  
Niru Dayal ◽  
Mette C Schladweiler ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Prostaglandin E2 ◽  
Inflammatory Responses ◽  
Oxide Particle ◽  
In Vivo Studies ◽  
Iron Oxide Particle ◽  
Soluble Iron

Derivatives of schisandrin with increased inhibitory potential on prostaglandin E2 and leukotriene B4 formation in vitro

2010 ◽  
Vol 18 (7) ◽  
pp. 2809-2815 ◽  
Author(s):  
Martina Blunder ◽  
Eva M. Pferschy-Wenzig ◽  
Walter M.F. Fabian ◽  
Antje Hüfner ◽  
Olaf Kunert ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Leukotriene B4 ◽  
Inhibitory Potential ◽  
Derivatives Of

scholarly journals Targeting redox regulatory site of protein kinase B impedes neutrophilic inflammation in lung injury

2018 ◽  
Author(s):  
Po-Jen Chen ◽  
I-Ling Ko ◽  
Chia-Lin Lee ◽  
Hao-Chun Hu ◽  
Fang-Rong Chang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Lung Injury ◽  
Inflammatory Responses ◽  
Protein Kinase B ◽  
Reduced Form ◽  
Human Neutrophils ◽  
Akt Inhibitor ◽  
Neutrophilic Inflammation

AbstractNeutrophil activation has a pathogenic effect in inflammatory diseases. Protein kinase B (PKB)/AKT regulates diverse cellular responses. However, the significance of AKT in neutrophilic inflammation is still not well understood. Here, we identified CLLV-1 as a novel AKT inhibitor. CLLV-1 inhibited respiratory burst, degranulation, chemotaxis, and AKT phosphorylation in activated human neutrophils and dHL-60 cells. Significantly, CLLV-1 blocked AKT activity and covalently reacted with AKT Cys310 in vitro. The AKT309-313 peptide-CLLV-1 adducts were determined by NMR or mass spectrometry assay. The alkylation agent-conjugated AKT (reduced form) level was also inhibited by CLLV-1. Additionally, CLLV-1 ameliorated lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. CLLV-1 acts as a covalent allosteric AKT inhibitor by targeting AKT Cys310 to restrain inflammatory responses in human neutrophils and LPS-induced ALI in vivo. Our findings provide a mechanistic framework for redox modification of AKT that may serve as a novel pharmacological target to alleviate neutrophilic inflammation.

Sign in / Sign up

Export Citation Format

Share Document