Background-Cell-derived Microparticles (MPs) are cellular membrane fragments with size ranging from 0.1 to 1 μm, derived from activated/apoptotic cells and characterized by an integral plasma membrane expressing population markers of the parental cell. The presence of phosphatidyl serine (PS) on the outer plasma membrane has been widely used as a marker to identify MPs. Recently, it has been suggested that a fraction of circulating PS– MPs may exist. Details on their cellular origin are however still lacking. Aim-We set up a multiparametric flow cytometric approach to identify, among the human circulating PS+ and PS– MPs, their cell origin. By combining the use of a high technology cytometer that allows the visualization of undetectable subpopulation of MPs with a multicolor staining, we are able to obtain an accurate overview of MPs and give a complete analysis of their characteristics and origin. Method-Human platelet free plasma (PFP) MPs from healthy volunteers (HV) (n=15) were characterized by a BD FACSAria IIUTM, a four lasers equipped cell sorter using simultaneously seven markers. Beads with definite and appropriate size (0.5/0.9 μm) were added to the sample to identify MPs; 7AAD was used to exclude debris. Results-The multiparametric approach allowed us to identify two populations of MPs (~70% PS+, ~30% PS-). More than 70% of PS+ MPs were CD31+ CD41+, confirming literature data that reported platelet-derived MPs as the most abundant circulating population. White blood cell (CD45+) derived MPs represented around 3% of total (50% PS-, 50% PS+); 20% of them were CD14+ deriving therefore from monocytes. Red blood cell (CD235+)-derived MPs were 8% of total and were both PS+(48%) and PS–(52%). Conclusions-the multicolor flow cytometry approach allowed us the simultaneous identification of PS+ and PS- MPs in PFP from HV and gives a significant improvement in the methodology applied until now to their characterization.
|Titolo:||HUMAN CIRCULATING MICROPARTICLES: A GLOBAL ASSESSMENT OF THEIR PHISICAL AND ANTIGENIC PROPRIETIES BY A MULTICOLOR FLOW CYTOMETRY APPROACH|
|Parole Chiave:||microparticles; flow cytometry;|
|Settore Scientifico Disciplinare:||Settore BIO/14 - Farmacologia|
Settore BIO/10 - Biochimica
|Data di pubblicazione:||set-2012|
|Digital Object Identifier (DOI):||10.2450/2011.0064-11|
|Appare nelle tipologie:||01 - Articolo su periodico|