Analysis of tetraspanin distribution on plasma and serum extracellular vesicles indicates that separate subpopulations carries CD9, CD63 and CD81

ABSTRACT: The ability to isolate extracellular vesicles (EVs) from blood is vital in the development of EVs as disease biomarkers. Both serum and plasma can be used, but few studies have compared these sources in terms of the quantity and type of EVs that are obtained. The aim of this study was therefore to determine the presence of different subpopulations of EVs in plasma and serum. Blood samples were collected from healthy subjects, from which plasma and serum were isolated in parallel. ACD-A or EDTA tubes were used for the collection of plasma, while serum was obtained in clot activator tubes. We previously developed a method utilising a combination of density cushion and size exclusion chromatography to isolate EVs from plasma with minimal contamination of lipoprotein particles. In the current study, we applied this method to both EDTA-plasma and serum. In addition, EVs were isolated by a combination of density cushion and density gradient or by bead immune capturing (anti-CD63, anti-CD9, and anti-CD81 beads). The subpopulations of EVs were analysed by nanoparticle tracking analysis, Western blot, single particle interferometric reflectance imaging sensing, conventional and nano flow cytometry, magnetic bead enzyme-linked immunosorbent assay, and mass spectrometry.This study shows that a larger number of CD9+ EVs are present in EDTA-plasma compared to ACD-plasma and serum, and the presence of CD41a on theses EVs suggests that they are released from platelets. Furthermore, only a small number of EVs in blood were double positive for CD63 and CD81. The CD63+ EVs were enriched in serum, while CD81+ vesicles were the rarest subpopulation in both plasma and serum. Together, these findings show that multiple subpopulations of EVs are present in blood including CD9+/CD41a+, CD9+/CD63+/CD41+, CD63+/CD41a+, CD63+/CD9+/CD81−, CD81+/CD9+/CD63−, and CD9+/CD63+/CD81+ and that their presence is dissimilar in EDTA-plasma, ACD-plasma and serum.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood Plasma

SUBMITTER: Proteomics Core Facility  

LAB HEAD: Cecilia Lässer

PROVIDER: PXD026863 | Pride | 2022-05-20

REPOSITORIES: Pride