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Pneumolysin-mediated activation of NFkappaB in human neutrophils is antagonized by docosahexaenoic acid.
- Source :
-
Clinical and experimental immunology [Clin Exp Immunol] 2005 May; Vol. 140 (2), pp. 274-81. - Publication Year :
- 2005
-
Abstract
- This study was designed to investigate the relationship between influx of extracellular Ca(2+), activation of NFkappaB and synthesis of interleukin-8 (IL-8) following exposure of human neutrophils to subcytolytic concentrations (8.37 and 41.75 ng/ml) of the pneumococcal toxin, pneumolysin, as well as the potential of the omega-3 polyunsaturated fatty acid, docosahexaenoic acid, to antagonize these events. Activation and translocation of NFkappaB were measured using a radiometric electrophoretic mobility shift assay, while influx of extracellular Ca(2+) and synthesis of IL-8 were determined using a radioassay and an ELISA procedure, respectively. Exposure of neutrophils to pneumolysin was accompanied by influx of Ca(2+), activation of NFkappaB, and synthesis of IL-8, all of which were eliminated by inclusion of the Ca(2+)-chelating agent, EGTA (10 m m), in the cell-suspending medium, as well as by pretreatment of the cells with docosahexaenoic acid (5 and 10 microg/ml). The antagonistic effects of docosahexaenoic acid on these pro-inflammatory interactions of pneumolysin with neutrophils were not attributable to inactivation of the toxin, and required the continuous presence of the fatty acid. These observations demonstrate that activation of NFkappaB and synthesis of IL-8, following exposure of neutrophils to pneumolysin are dependent on toxin-mediated influx of Ca(2+) and that these potentially harmful activities of the toxin are antagonized by docosahexaenoic acid.
- Subjects :
- Adult
Bacterial Proteins antagonists & inhibitors
Bacterial Proteins metabolism
Calcium metabolism
Cells, Cultured
Hemolysis drug effects
Hemolysis immunology
Humans
Interleukin-8 biosynthesis
Neutrophil Activation immunology
Neutrophils drug effects
Neutrophils immunology
Neutrophils metabolism
Recombinant Proteins immunology
Recombinant Proteins metabolism
Streptolysins antagonists & inhibitors
Streptolysins metabolism
Bacterial Proteins immunology
Docosahexaenoic Acids pharmacology
NF-kappa B metabolism
Neutrophil Activation drug effects
Streptolysins immunology
Subjects
Details
- Language :
- English
- ISSN :
- 0009-9104
- Volume :
- 140
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Clinical and experimental immunology
- Publication Type :
- Academic Journal
- Accession number :
- 15807851
- Full Text :
- https://doi.org/10.1111/j.1365-2249.2005.02757.x