Immunoaffinity-Based Protocol to Enrich Nervous System Cell-, Lung Alveolar Cell-, and Hepatocyte-Derived Extracellular Vesicles From Human Plasma.

By preserving molecular information inherited from the source cell, extracellular vesicles (EVs) can serve as biomarkers for tissue health or disease, paving the way for liquid biopsy applications. The enrichment of tissue-specific EVs (TS-EVs) from human biofluids can be challenging due to technical and methodological limitations. Here, we use single and sequential immunoaffinity capture workflows to enrich antigen-specific EVs circulating in human blood. We demonstrate the specificity, efficiency, and consistency of our approach for enriching blood plasma EV subpopulations from the nervous system, alveolar cells and hepatocytes. The enriched subpopulations are characterized by canonical EV features and markers, as well as co-localization of tissue-specific and general markers on the surface. We provide a validated workflow to derive multiple EV subpopulations from circulation, leveraging their promise as informative biomarkers of tissue status and enabling liquid biopsy and biomarker discovery.