Abstract
Extracellular vesicles (EVs) derived from blood cells are promising biomarkers for various diseases. However, they are difficult to measure accurately in plasma due to their small size. Here, we demonstrate that platelet-derived EVs in plasma can be measured using solid-phase proximity ligation assay with high sensitivity and specificity using very small sample volume of biological materials. The results correlate well with high-sensitivity flow cytometry with the difference that the smallest EVs are detected. Briefly, the EVs are first captured on a solid phase, using lactadherin binding, and detection requires recognition with two antibodies followed by qPCR. The assay, using cholera toxin subunit-B or lactadherin as capture agents, also allowed detection of the more rare population of tissue factor (TF)-positive EVs at a concentration similar to sensitive TF activity assays. Thus, this assay can detect different types of EVs with high specificity and sensitivity, and has the potential to be an attractive alternative to flow cytometric analysis of preclinical and clinical samples. Improved techniques for measuring EVs in plasma will hopefully contribute to the understanding of their role in several diseases.
Highlights
A series of experiments were conducted on platelet-derived Extracellular vesicles (EVs) (CD41 þ /CD61 þ )
We show that EVs can be accurately measured in only a few microliters of plasma using a qPCR machine, standard equipment in most laboratories which is cheap and easy to handle as compared with a flow cytometer
Based on the solid-phase proximity ligation assay (SP-PLA) technique, we have developed an assay that and sensitively detect platelet-derived EVs (CD41 þ /CD61þ and PS þ ) as well as TFþ EVs in small amounts of Detection of EVs in Plasma by SP-PLA Thulin et al e257
Summary
Extracellular vesicles (EVs) constitute a heterogeneous population ranging from 0.03 to 1 μm in size that are released from cells either by membrane budding (microvesicles) or by exocytosis of intracellular multivesicular bodies (exosomes).[1,2] Exosomes can be released by secretory autophagy with and without membrane fusion.[3,4,5] The release of EVs is induced by cellular activation, injury, or stress, and their functions vary broadly depending on the source, the activation state of the parental cell, and the generation process.[1,6] This results in EV populations with different content and surface antigens that disseminate the functions of the parental cell and makes it possible to detect and characterize them.[7,8] EVs are received February 14, 2018 accepted after revision June 13, 2018.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
