Figure 1 .

Mechanism of EV to cell interactions. Exosome uptake appears primarily mediated by (a) the standard phagocytosis machinery in professional phagocytes, and (b) receptor-mediated endocytosis in other cell types (e.g. CD29/CD81- or fibronectin-mediated interactions). However, exosomes also exhibit (c) paracrine signaling, where factors released by exosomes can directly adhere to cell surface receptors, and (d) receptor-mediated membrane fusion via interactions between exosome and cell membrane proteins (e.g. syncytins and MFSD2a or ASCF2).