fig3

Figure 3. Schematic illustration of EV biogenesis, composition, and uptake. EVs are generated via two primary pathways: (1) the endosomal pathway, where early endosomes mature into late endosomes, which form ILVs within MVBs. These MVBs release ILVs as exosomes upon fusion with the plasma membrane; (2) direct budding from the plasma membrane, yielding microvesicles. EVs are composed of a lipid bilayer embedded with transmembrane proteins and enclosing a luminal cargo of diverse nucleic acids, proteins, and lipids. EVs can be internalized by recipient cells through endocytosis or direct membrane fusion. EVs: Extracellular vesicles; circRNA: circular RNA; ER: endoplasmic reticulum; ESCRT: endosomal sorting complex required for transport; FAS: Fas cell surface death receptor; HSP70: heat shock protein 70; HSP90: heat shock protein 90; ILVs: intraluminal vesicles; lncRNA: long non-coding RNA; MHC I: major histocompatibility complex class I; MHC II: major histocompatibility complex class II; mRNA: messenger RNA; miRNA: microRNA; mtDNA: mitochondrial DNA; PS: phosphatidylserine; ssDNA: single-stranded DNA; Tsg101: tumor susceptibility gene 101; MVBs: multivesicular bodies.