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 BorreliaSpirochetes Upregulate Release and Activation of Matrix Metalloproteinase Gelatinase B (MMP-9) and Collagenase 1 (MMP-1) in Human Cells

2001 ◽  
Vol 69 (1) ◽  
pp. 456-462 ◽  
Author(s):  
Joseph A. Gebbia ◽  
James L. Coleman ◽  
Jorge L Benach
Keyword(s):  
Lyme Disease ◽  
Matrix Metalloproteinase ◽  
Human Peripheral Blood ◽  
Umbilical Vein ◽  
Active Form ◽  
Human Neutrophils ◽  
Blood Monocytes ◽  
Gelatinase B ◽  
Matrix Metalloproteinase 1

ABSTRACT Borrelia burgdorferi, the spirochetal agent of Lyme disease, stimulated human peripheral blood monocytes to release pro-matrix metalloproteinase-9 (gelatinase B; pro-MMP-9) and active matrix metalloproteinase-1 (collagenase-1; MMP-1). Human neutrophils also released pro-MMP-9 and a 130-kDa protein with gelatinolytic activity in response to live B. burgdorferi. In addition, U937 cells and human keratinocyte cells were also stimulated to release pro-MMP-9 under the same conditions. However, human umbilical vein endothelial cells (HUVECs) released pro-MMP-9 and pro-MMP-2 in a constitutive manner and were not influenced by live spirochetes. MMPs produced by human monocytes also enhanced the penetration of B. burgdorferi through extracellular matrix component barriers in vitro. Plasmin stabilized on the surface of the Lyme disease spirochete was shown to activate pro-MMP-9 to its active form. This active form was also observed in the plasma of mice infected with a relapsing fever borrelia. These results suggest that borreliae can upregulate MMPs and possibly mediate an activation cascade initiated by plasmin bound to the microbial surface. MMPs may play a role in dissemination of the Lyme disease spirochete and in the pathogenesis ofBorrelia infection.

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 Hepoxilin A3-specific binding in human neutrophils

1996 ◽  
Vol 313 (2) ◽  
pp. 537-541 ◽  
Author(s):  
Denis REYNAUD ◽  
Peter DEMIN ◽  
Cecil R. PACE-ASCIAK
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Leukotriene B4 ◽  
Proteinase K ◽  
Human Neutrophils ◽  
Scatchard Analysis ◽  
Intact Cells ◽  
Specific Binding Sites ◽  
Binding Data ◽  
Hepoxilin A3

Hepoxilins have been shown to release calcium from intracellular stores in human neutrophils [Dho, Grinstein, Corey, Su and Pace-Asciak (1990) Biochem. J. 266, 63-68; Laneuville, Reynaud, Grinstein, Nigam and Pace-Asciak (1993) Biochem. J. 295, 393-397]. In this paper we report that tritium-labelled hepoxilin A3 (8S) binds to broken neutrophil membranes in a time-, substrate- and temperature-dependent fashion. Specific binding was displaced with unlabelled hepoxilin A3. Specific binding was greatest at 37 °C. Competitive binding was best observed with unlabelled hepoxilin A3 (8S); the glutathione conjugate, HxA3-C (8S or 8R), or 12(S)-hydroxyeicosatetraenoic acid was less active. Similarly inactive in displacing the bound radiolabelled hepoxilin A3 was leukotriene B4 as well as a variety of prostaglandins and thromboxane B2. Formylmethionyl-leucylphenylalanine was similarly inactive in competing for the hepoxilin binding sites. Specific binding was inhibited by pretreatment of the broken membranes during 30 min at 37 °C with proteinase K, while specific binding of the intact cells was unaffected. Scatchard analysis of binding data revealed a single population of binding sites with apparent KD and Bmax. of 79.3±9.1 nM and 8.86±1.4 pmol/ml per 2×106 cells (±S.E.M.) respectively reflecting approx. 2.67×106 sites/cell. These results demonstrate for the first time that neutrophils contain specific binding sites to hepoxilin A3.

Leukocyte-induced vascular protein leakage in cat mesentery

1991 ◽  
Vol 261 (6) ◽  
pp. H1872-H1879 ◽  
Author(s):  
P. Kubes ◽  
M. B. Grisham ◽  
J. A. Barrowman ◽  
T. Gaginella ◽  
D. N. Granger
Keyword(s):  
Leukocyte Adhesion ◽  
Platelet Activating Factor ◽  
Leukotriene B4 ◽  
Superoxide Production ◽  
Vascular Integrity ◽  
Fourfold Increase ◽  
Protein Leakage ◽  
Pmn Functions

The overall objective of this study was to determine whether leukocyte adherence and/or emigration is a prerequisite for the increased vascular protein leakage associated with acute inflammation. An in vivo preparation was used to monitor intestinal vascular protein leakage as well as polymorphonuclear leukocyte (PMN) adhesion and emigration in feline mesenteric microvessels exposed to platelet-activating factor (PAF) and leukotriene B4 (LTB4). Local intra-arterial infusion of PAF (4 ng/min) produced a fourfold increase in vascular protein leakage. A 50-fold higher concentration of LTB4 had no effect on vascular protein efflux. LTB4, however, did potentiate the PAF-induced vascular protein leakage. Both inflammatory mediators caused leukocytes to adhere to endothelial cells in postcapillary venules; however, leukocyte emigration was observed only in the presence of PAF. PAF-induced leukocyte adhesion and emigration and the increased vascular protein leakage were inhibited by a monoclonal antibody (MoAb IB4) directed against the common beta-subunit of the adhesive glycoprotein complex CD11/CD18. MoAb IB4 also prevented LTB4-induced leukocyte adhesion. Both PAF and LTB4 caused degranulation of cat PMNs in vitro, yet superoxide production was stimulated by PAF only. The data derived from these in vivo and in vitro studies indicate that leukocyte adhesion per se does not necessarily lead to increased vascular protein leakage and leukocyte emigration. Adhesion-dependent PMN functions such as emigration and superoxide production may play an important role in producing the alterations in vascular integrity observed in inflamed microvessels.

Phospholipase A2 activation in human neutrophils requires influx of extracellular Ca2+ and leukotriene B4

1995 ◽  
Vol 268 (1) ◽  
pp. C138-C146 ◽  
Author(s):  
S. Reddy ◽  
R. Bose ◽  
G. H. Rao ◽  
M. Murthy
Keyword(s):  
Ethylene Glycol ◽  
Phospholipase A2 ◽  
Platelet Activating Factor ◽  
Leukotriene B4 ◽  
Lipid Mediators ◽  
Oxidation Products ◽  
Human Neutrophils ◽  
Tetraacetic Acid ◽  
A 23187 ◽  
Transient Elevation

We have demonstrated that phospolipase A2 (PLA2) activation in human neutrophils requires both the influx of extracellular Ca2+ and leukotriene B4 (LTB4). Surprisingly, the eicosanoids (LTB4 and its omega-oxidation products) formed were quantitatively very similar in both thapsigargin (Thap)- and A-23187-stimulated neutrophils. In contrast, Thap had very little effect on the activation of PLA2 when 5-lipoxygenase (5-LO) was blocked by BW755C or MK-886, whereas A-23187 caused a substantial activation. The lack of PLA2 activation in Thap-stimulated neutrophils results from the inhibition of LTB4 formation in the presence of 5-LO inhibitors. It appears that A-23187 activates both LTB4-dependent and -independent PLA2, whereas Thap activates LTB4-dependent PLA2. Experiments with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid demonstrated that activation of Thap-sensitive PLA2 and 5-LO requires the influx of Ca2+. Neither the transient elevation of cytosolic Ca2+ from intracellular stores nor the sustained Ca2+ influx alone without LTB4 appears sufficient to cause the activation of LTB4-dependent PLA2. We suggest that the activation of LTB4-dependent PLA2 involves 1) a sustained elevation of cytosolic Ca2+ coupled to the influx of extracellular Ca2+ and 2) a coupling between LTB4 and its receptor. We conclude that LTB4-dependent PLA2 plays an important role in the poststimulatory formation of lipid mediators such as prostaglandins, leukotrienes, and platelet-activating factor.

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.

Acute lung injury in endotoxemic pigs: role of leukotriene B4

1995 ◽  
Vol 78 (3) ◽  
pp. 1121-1131 ◽  
Author(s):  
T. J. VanderMeer ◽  
M. J. Menconi ◽  
B. P. O'Sullivan ◽  
V. A. Larkin ◽  
H. Wang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Platelet Activating Factor ◽  
Leukotriene B4 ◽  
Important Mediator ◽  
Preliminary Study ◽  
Receptor Upregulation ◽  
To Receive

The role of leukotriene B4 (LTB4) in the pathogenesis of acute lung injury was examined in endotoxemic pigs. In a preliminary study, the activity and specificity of an LTB4-receptor antagonist, LY-306669, were evaluated. In vitro, LY-306669 completely blocked the functional upregulation of phagocyte opsonin receptors induced by LTB4 but had a much smaller effect on opsonin receptor upregulation induced by platelet-activating factor. In pigs treatment with LY-306669 prevented leukopenia induced by injection of authentic LTB4 but had no effect on the hematologic or hemodynamic effects of PAF or U-48816, a thromboxane-A2 mimetic. In a second study, pigs received an intravenous priming dose of lipopolysaccharide (LPS) at time (t) = -18 h and were randomized to receive 1) no further treatment (n = 5), 2) LPS (250 micrograms/kg over 1 h beginning at t = 0 h) and LY-306669 (10 mg/kg bolus and 3 mg.kg-1.h-1 infusion beginning at t = -15 min) (n = 7), or 3) LPS and vehicle (n = 6). Treatment with LY-306669 significantly ameliorated LPS-induced hypoxemia, pulmonary edema, and alveolitis. These data suggest that LTB4 is an important mediator of pulmonary dysfunction and transendothelial migration of neutrophils in LPS-induced acute lung injury.

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