Mechanism of Autophagic Extracellular Vesicles Revealed.

Recent work by Mao and colleagues identifies a distinct class of small extracellular vesicles, termed autophagic extracellular vesicles (AEVs), generated from amphisomes upon autophagy induction. In this commentary, we discuss how this study provides important mechanistic insight into the coupling between autophagy and secretion. AEVs are molecularly and functionally distinct from canonical exosomes, being enriched in autophagy-related components such as LC3 and p62, and dependent on core ATG machinery for their biogenesis. Notably, their secretion is enhanced by autophagy induction and contributes to intercellular communication, particularly in the context of viral infection. These findings position amphisomes as critical sorting hubs that direct cargo toward either degradation or secretion, thereby integrating autophagic and endolysosomal pathways. We further highlight how these results intersect with prior evidence implicating SNARE-dependent mechanisms, including VAMP7 and stress-responsive regulators such as GRASP55, in unconventional secretion. Finally, we discuss key unresolved questions, particularly the mechanisms underlying the generation of small intraluminal vesicles within amphisomes and the role of ESCRT machinery in this process. Overall, the identification of AEVs adds a new layer of complexity to extracellular vesicle biology and opens new avenues for understanding how autophagy contributes to intercellular signaling in health and disease.