Short time exposure to lipopolysaccharide is sufficient to activate human monocytes.
Détails
ID Serval
serval:BIB_97E99BC52DEA
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Short time exposure to lipopolysaccharide is sufficient to activate human monocytes.
Périodique
Journal of Immunology
ISSN
0022-1767[print], 0022-1767[linking]
Statut éditorial
Publié
Date de publication
06/1993
Volume
150
Numéro
11
Pages
5086-5093
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Publication Status: ppublish
Résumé
Very little is known about early events in LPS binding and about the duration of LPS exposure required to activate monocytes. In the present study, we have investigated the kinetics of LPS binding to human monocytes and the time of exposure required to trigger the synthesis of TNF-alpha. We directly followed the binding of FITC-labeled LPS to monocytes by flow cytometry or confocal laser microscopy. LPS was able to bind to the cell surface within 1 min of exposure, and was internalized within 5 min. Equilibrium was reached within 15 min at all but the lowest LPS concentration tested (10 ng/ml). Binding was dependent on the presence of LPS-binding protein, supplied either as a plasma component or in purified form, and inhibited by an anti-CD14 mAb (MY4). Polymyxin B, an inhibitor of LPS-mediated activation, essentially abrogated the LPS-binding protein- and CD14-dependent binding of LPS to monocytes. Using either the anti-CD14 mAb or polymyxin B to block further LPS binding, we found that 5 to 10 min of exposure was sufficient to trigger maximal TNF-alpha release. Similarly, monocytes washed after 5 to 15 min exposure to eliminate LPS also produced high levels of TNF-alpha transcripts without further presence of LPS in the medium. We conclude that a few minutes of exposure to physiologically relevant concentrations of LPS are sufficient to trigger both maximal binding and activation of monocytes.
Mots-clé
Acute-Phase Proteins, Animals, Antigens, CD/physiology, Antigens, CD14, Antigens, Differentiation, Myelomonocytic/physiology, Binding, Competitive, Carrier Proteins/metabolism, Fluorescein-5-isothiocyanate/metabolism, Humans, Kinetics, Lipopolysaccharides/metabolism, Lipopolysaccharides/pharmacology, Macrophage Activation/drug effects, Membrane Glycoproteins, Mice, Monocytes/drug effects, Monocytes/immunology, Polymyxin B/pharmacology, RNA, Messenger/biosynthesis, RNA, Messenger/metabolism, Tumor Necrosis Factor-alpha/biosynthesis, Tumor Necrosis Factor-alpha/genetics
Pubmed
Web of science
Création de la notice
24/01/2008 15:39
Dernière modification de la notice
20/08/2019 14:59