Glycosylation of extracellular vesicles: current knowledge, tools and clinical perspectives

Figures & data

Table 1. A primer of glycan features relevant to EVs.

Glycan feature	Representative structures			EV relevance
Polylactosamine				Enriched
α2,6 linked sialic acid				Enriched
High mannose N-glycan				Enriched
Complex type N-glycan				Enriched
O-linked blood group antigens A/B				Excluded

Figure 1. Enrichment for specific glycans to EVs.

Lectin microarrays have shown that EVs are preferentially enriched in certain glycan features compared to more diverse glycan repertoire of the producing cell membranes [38,39]. These features include polylactosamine and α2-6 linked sialic acid residues, and high mannose and complex type N-glycans. Exclusion of blood group A/B antigens was also identified. Glycans of this figure are representative of these features but are not definitive structures as these are not possible to obtain through lectin microarrays alone.

Figure 2. A protocol for the purification of EVs using a lectin-bead approach.

Following a lectin microarray screen, STL was found to bind to uEVs with greater specificity than urine glycoproteins [48]. Incubation of undiluted urine with biotinylated STL and streptavidin-conjugated Dynabeads allowed for magnetic recovery of uEVs.

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