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Neutrophil Extracellular Traps: How to Generate and Visualize Them
Published on: February 24, 2010
Ectosomes released by human neutrophils are specialized functional units
1Department of Research, University Hospital Basel, Switzerland. hessch@ubaclu.unibas.ch
Journal of Immunology (Baltimore, Md. : 1950)
|October 8, 1999
Summary
Human polymorphonuclear leukocytes (PMN) release ectosomes during activation. These PMN-derived ectosomes concentrate antimicrobial proteins and complement receptors, enhancing bacterial targeting.
Area of Science:
- Immunology
- Cell Biology
Background:
- Human polymorphonuclear leukocytes (PMN) are key immune cells involved in inflammation.
- The release and function of PMN-derived ectosomes are not fully understood.
Purpose of the Study:
- To investigate the release and characteristics of ectosomes from activated human PMN.
- To determine the functional role of these ectosomes in antimicrobial activity.
Main Methods:
- In vitro and in vivo activation of human PMN.
- Analysis of protein sorting into and out of PMN-derived ectosomes using biotinylation.
- Detection of specific proteins (CR1, myeloperoxidase, elastase, CD63, CD14, CD59, CD55, CD46) on PMN and ectosomes.
Main Results:
- PMN release ectosomes independently of complement activation.
- Ectosomes exhibit specific protein sorting, concentrating complement receptor 1 (CR1).
- Antimicrobial enzymes (myeloperoxidase, human leukocyte elastase) and complement regulators (CD59) colocalize with CR1 on ectosomes.
Conclusions:
- PMN-derived ectosomes act as organized 'ecto-organelles'.
- These ectosomes efficiently bind opsonized bacteria via CR1.
- Ectosomes focus antimicrobial activity, suggesting a novel mechanism in innate immunity.
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