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

ABSTRACT: The 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 new set of five protein categories displaying different relative abundance in distinct EV populations. We demonstrate the presence of exosomal and non-exosomal subpopulation within small EVs, and propose their differential separation by immuno-isolation using either CD63, CD81 or CD9. Our work thus provides new guidelines to define subtypes of EVs for future functional studies.

INSTRUMENT(S): LTQ Orbitrap, Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Dendritic Cell

SUBMITTER: Guillaume Arras  

LAB HEAD: Damarys Loew

PROVIDER: PXD003257 | Pride | 2016-02-11

REPOSITORIES: Pride