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Proteomic comparison defines novel markers to characterize heterogeneous populations of extracellular vesicle subtypes.

Proceedings of the National Academy of Sciences of the United States of America (2016-02-10)
Joanna Kowal, Guillaume Arras, Marina Colombo, Mabel Jouve, Jakob Paul Morath, Bjarke Primdal-Bengtson, Florent Dingli, Damarys Loew, Mercedes Tkach, Clotilde Théry
RÉSUMÉ

Extracellular vesicles (EVs) have become the focus of rising interest because of their numerous functions in physiology and pathology. Cells release heterogeneous vesicles of different sizes and intracellular origins, including small EVs formed inside endosomal compartments (i.e., exosomes) and EVs of various sizes budding from the plasma membrane. Specific markers for the analysis and isolation of different EV populations are missing, imposing important limitations to understanding EV functions. Here, EVs from human dendritic cells were first separated by their sedimentation speed, and then either by their behavior upon upward floatation into iodixanol gradients or by immuno-isolation. Extensive quantitative proteomic analysis allowing comparison of the isolated populations showed that several classically used exosome markers, like major histocompatibility complex, flotillin, and heat-shock 70-kDa proteins, are similarly present in all EVs. We identified proteins specifically enriched in small EVs, and define a set of five protein categories displaying different relative abundance in distinct EV populations. We demonstrate the presence of exosomal and nonexosomal subpopulations within small EVs, and propose their differential separation by immuno-isolation using either CD63, CD81, or CD9. Our work thus provides guidelines to define subtypes of EVs for future functional studies.

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Description du produit

Sigma-Aldrich
IgG normale de souris, Normal Mouse IgG Polyclonal Antibody control validated for use in Immunoprecipitation & Western Blotting.
Sigma-Aldrich
Anticorps anti-CD9, clone MM2/57, clone MM2/57, Chemicon®, from mouse
Sigma-Aldrich
Anti-TSG101 (C-terminal) antibody produced in rabbit, ~1.5 mg/mL, affinity isolated antibody, buffered aqueous solution