Isolation of circulating exosomes and identification of exosomal PD-L1 for predicting immunotherapy response. Issue 25 (14th June 2022)

• Record Type: Journal Article
• Authors: Zhang, Junli; Zhu, Yifan; Guan, Mengting; Liu, Yingying; Lv, Min; Zhang, Chongwei; Zhang, Hongling; Zhang, Zhenzhong
• Is Part Of: Nanoscale. Volume 14:Issue 25(2022)
• Page Start: 8995
• Page End: 9003
• Publication Date: 2022-06-14
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d2nr00829g
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Isolation of exosomes by iodixanol density gradient centrifugation could exclude the interference and aptamers could penetrate the glycosylated PD-L1 protein of exosomes, realizing sensitive detection of exosomal PD-L1. Abstract : Exosomes, a subgroup of extracellular vesicles secreted by multiple cells, have great potential as cancer biomarkers in clinical applications. However, enrichment and detection of exosomes from complex media remain a huge challenge due to their small size. Herein, we used iodixanol density gradient centrifugation for the isolation and purification of exosomes and label-free detection of exosomal PD-L1 using a biochip based on surface plasmon resonance (SPR-ExoPD-L1 ). The obtained exosomes are lipid-bilayer vesicles and the classical exosome markers CD9, CD63 and CD81 are highly enriched. Besides, PD-L1 is specifically expressed on exosomes instead of non-vesicular components or large extracellular vesicles. Compared with enzyme-linked immunosorbent assays, the SPR-ExoPD-L1 assay could better distinguish exosomes derived from melanoma cells with different levels of PD-L1. Accurate measurement of exosomal PD-L1 could provide critical clinical information for cancer diagnosis and personalized immunotherapy of cancer.