Interactions between lipopolysaccharides and blood factors on the stimulation of equine polymorphonuclear neutrophils.
Abstract: In horses, the mechanisms of lipopolysaccharide (LPS) stimulation of isolated neutrophils to produce reactive oxygen species remain unknown. We re-investigated this problem by monitoring the luminol-enhanced chemiluminescence (CL) produced by LPS-stimulated equine neutrophils. The neutrophils were isolated from horse blood by discontinuous density gradient centrifugation (> or = 99% neutrophils; viability > or = 98%). Increasing concentrations of Escherichia coli (E. coli) LPS (from 0.01-10 microg ml(-1)) were used to activate the neutrophils. When LPS was used directly, without another stimulator, the respiratory burst of neutrophils was not activated (N=12 horses; n=5 assays per horse). On the contrary, when LPS was added to whole blood, the neutrophils isolated from this blood were stimulated in a LPS dose-dependent manner, but polymyxin B added to whole blood suppressed this stimulation (N=2; n=6). LPS dissolved in autologous equine plasma stimulated the isolated neutrophils in a dose-dependent manner from 0.1-10 microg ml(-1) (N=5; n=12). Heat inactivation of the plasma abolished this CL increase (N=2; n=5). LPS added to equine albumin did not stimulate the isolated neutrophils (N=2; n=5). On the contrary, the addition of gamma-globulins (1 mg ml(-1)) to LPS (10 microg ml(-1)) led to the stimulation of neutrophils (N=2; n=5). We concluded that LPS did not directly stimulate the isolated equine neutrophils, but that plasmatic factors are needed for the stimulation of these cells by LPS.
Publication Date: 1998-10-09 PubMed ID: 9764724DOI: 10.1016/s0165-2427(98)00142-1Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research study aims to explain how lipopolysaccharide (LPS), a component of bacteria, stimulates neutrophils, a type of blood cell, in horses. It concludes that LPS does not trigger these cells directly; instead, certain plasma (the liquid part of blood) factors are necessary for this stimulation.
Research Method
- The research involved studying the interaction of lipopolysaccharide (LPS) with equine polymorphonuclear neutrophils, a type of white blood cell in horses, and understanding how this interaction induces the generation of reactive oxygen species (ROS), which plays a role in the immune response.
- The neutrophils were isolated from horse blood using a technique called discontinuous density gradient centrifugation. This method ensures high purity (> or = 99%) and viability (> or = 98%) of the neutrophils.
- Different concentrations of LPS, derived from E. coli, were used to stimulate the neutrophils. The process of ROS production, termed as respiratory burst, was then monitored.
Main Findings
- When LPS was added directly to the isolated neutrophils, there was no activation of the respiratory burst. This indicated a lack of responsiveness by the immune cells to LPS alone.
- However, when LPS was added to whole blood, the neutrophils displayed a dose-dependent stimulation, suggesting that other factors in the blood might be crucial for the observed response.
- When polymyxin B, a molecule known for neutralizing LPS, was added to the LPS-activated blood, stimulation of neutrophils was suppressed.
- When LPS was dissolved in autologous equine plasma (plasma from the same horse), it stimulated the isolated neutrophils in a dose-dependent manner.
- When the plasma was heat-inactivated, it could not induce any response, implying heat-labile factors in plasma were essential for the stimulation.
- Dissolving LPS in equine albumin, a protein in plasma, did not stimulate the neutrophils. On the other hand, when LPS was added to gamma-globulins (a type of protein in blood plasma), a significant stimulation of neutrophils was seen.
Conclusion
- The study concluded that LPS in isolation cannot stimulate equine neutrophils.
- The presence of certain plasma factors seems to be critical for the activation of these immune cells by LPS.
- This finding is significant as it helps to understand the immune response in horses and can be beneficial for the diagnosis and treatment of bacterial infections.
Cite This Article
APA
Benbarek H, Deby-Dupont G, Caudron I, Grülke S, Deby C, Lamy M, Serteyn D.
(1998).
Interactions between lipopolysaccharides and blood factors on the stimulation of equine polymorphonuclear neutrophils.
Vet Immunol Immunopathol, 64(4), 313-322.
https://doi.org/10.1016/s0165-2427(98)00142-1 Publication
Researcher Affiliations
- Anesthésiologie Générale et Pathologie Chirurgicale des Grands Animaux, Faculté de Médecine Vétérinaire, B 43, Domaine Universitaire du Sart Tilman, Liège, Belgium. cbo@ulg.ac.be
MeSH Terms
- Animals
- Blood Physiological Phenomena
- Dose-Response Relationship, Drug
- Horses / immunology
- Lipopolysaccharides / pharmacology
- Neutrophil Activation / drug effects
- Neutrophils / drug effects
Citations
This article has been cited 9 times.- Barton AK, Richter IG, Ahrens T, Merle R, Alalwani A, Lilge S, Purschke K, Barnewitz D, Gehlen H. MMP-9 Concentration in Peritoneal Fluid Is a Valuable Biomarker Associated with Endotoxemia in Equine Colic.. Mediators Inflamm 2021;2021:9501478.
- Martin LM, Johnson PJ, Amorim JR, DeClue AE. Effects of Orally Administered Resveratrol on TNF, IL-1β, Leukocyte Phagocytic Activity and Oxidative Burst Function in Horses: A Prospective, Randomized, Double-Blinded, Placebo-Controlled Study.. Int J Mol Sci 2020 Feb 20;21(4).
- Sheats MK. A Comparative Review of Equine SIRS, Sepsis, and Neutrophils.. Front Vet Sci 2019;6:69.
- Boly R, Franck T, Kohnen S, Lompo M, Guissou IP, Dubois J, Serteyn D, Mouithys-Mickalad A. Evaluation of Antiradical and Anti-Inflammatory Activities of Ethyl Acetate and Butanolic Subfractions of Agelanthus dodoneifolius (DC.) Polhill & Wiens (Loranthaceae) Using Equine Myeloperoxidase and Both PMA-Activated Neutrophils and HL-60 Cells.. Evid Based Complement Alternat Med 2015;2015:707524.
- DeClue AE, Nickell J, Chang CH, Honaker A. Upregulation of proinflammatory cytokine production in response to bacterial pathogen-associated molecular patterns in dogs with diabetes mellitus undergoing insulin therapy.. J Diabetes Sci Technol 2012 May 1;6(3):496-502.
- Lewis DH, Chan DL, Pinheiro D, Armitage-Chan E, Garden OA. The immunopathology of sepsis: pathogen recognition, systemic inflammation, the compensatory anti-inflammatory response, and regulatory T cells.. J Vet Intern Med 2012 May-Jun;26(3):457-82.
- Grulke S, Franck T, Gangl M, Péters F, Salciccia A, Deby-Dupont G, Serteyn D. Myeloperoxidase assay in plasma and peritoneal fluid of horses with gastrointestinal disease.. Can J Vet Res 2008 Jan;72(1):37-42.
- Hedges JF, Demaula CD, Moore BD, McLaughlin BE, Simon SI, MacLachlan NJ. Characterization of equine E-selectin.. Immunology 2001 Aug;103(4):498-504.
- Grulke S, Benbarek H, Caudron I, Deby-Dupont G, Mathy-Hartert M, Farnir F, Deby C, Lamy M, Serteyn D. Plasma myeloperoxidase level and polymorphonuclear leukocyte activation in horses suffering from large intestinal obstruction requiring surgery: preliminary results.. Can J Vet Res 1999 Apr;63(2):142-7.
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