Large Extracellular Vesicles Step Out of the Shadow of Exosomes in Landmark Review

Cells shed far more than molecular dust. Scattered across their surfaces and along their migratory trails, they release a menagerie of membrane-bound packages that dwarf the exosomes that have dominated the extracellular vesicle literature for two decades. A comprehensive review published in Nature Reviews Molecular Cell Biology now assembles this scattered field into a coherent framework, arguing that large extracellular vesicles, defined as vesicles exceeding 200 nanometres in diameter, deserve systematic attention as a biologically distinct and therapeutically promising class of cellular messengers. The review, led by Yuwei Huang and Li Yu of Tsinghua University and Xi’an Jiaotong University, synthesises findings that have accumulated rapidly since several of the field’s most striking subtypes were discovered only within the past decade.

The case for treating large extracellular vesicles as their own category rests on a fundamental difference in origin. Small extracellular vesicles arise from two well-characterised sources: the endosomal system, which produces exosomes when multivesicular bodies fuse with the plasma membrane, and the plasma membrane itself, which buds off small ectosomes. Most large extracellular vesicles, by contrast, stem directly from the plasma membrane, although the review emphasises that the various subtypes follow strikingly different biogenesis routes. This distinction matters because it shapes what the vesicles carry, how they are released, and what they do once they arrive at a recipient cell. A vesicle born from a dying cell’s collapsing membrane carries a very different cargo than one pinched off from the rear of a migrating cell or extruded from a neuron under proteotoxic stress.

The classical cast of large vesicles includes apoptotic bodies, microvesicles and large oncosomes, each recognised for years and each associated with distinct biology. Apoptotic bodies form as dying cells disassemble themselves, a process driven by caspase-mediated activation of ROCK1, which triggers the actomyosin contraction underlying membrane blebbing. These fragments are far more than debris: they broadcast find-me and eat-me signals that orchestrate the orderly clearance of dead cells by phagocytes, and recent work shows they can stimulate stem cell proliferation during tissue maintenance and couple bone resorption to bone formation. Microvesicles, shed directly from the plasma membrane of viable cells, depend on the ARF6–myosin light chain–actomyosin axis for their scission, and tumour cells exploit this pathway to spread oncogenic receptors such as EGFRvIII and drug-resistance proteins like P-glycoprotein to neighbouring cells. Large oncosomes, the giant vesicles shed by cancer cells, have been linked to loss of the formin DIAPH3 and to the reprogramming of fibroblasts in the tumour microenvironment through MYC-dependent mechanisms.

The most exciting chapters of the review concern the newer subtypes, several of which were unknown when the extracellular vesicle field consolidated its nomenclature under the MISEV guidelines. Migrasomes, discovered in 2015 by Li Yu’s group, form on retraction fibres left behind by migrating cells and serve as organelles for controlled release of cytoplasmic contents during cell migration. Their formation depends on the assembly of micron-scale tetraspanin-enriched macrodomains, driven by sphingomyelin synthase 2, phosphatidylinositol 4,5-bisphosphate signalling through Rab35, and palmitoylation of the tetraspanin Tspan4. Migrasomes have since been implicated in zebrafish organ morphogenesis, embryonic angiogenesis, mitochondrial quality control through a process termed mitocytosis, and even coagulation, with neutrophil-derived migrasomes identified as essential components of the clotting system.

Equally remarkable are the vesicles that cells use to jettison damaged components. Exophers, first described in Caenorhabditis elegans neurons in 2017, are enormous vesicles through which stressed neurons extrude toxic protein aggregates and dysfunctional mitochondria, providing a proteostasis escape route with obvious implications for neurodegenerative disease. Mitophers, reported in 2023, represent a form of mitochondria-specific ectocytosis through which sperm cells regulate their mitochondrial complement and, consequently, their fertility, establishing a paradigm for cargo-selective packaging of entire organelles into large vesicles. Blebbisomes, characterised in 2025, are large, organelle-rich vesicles with startling cell-like properties, carrying broad organellar cargo and expanding the functional repertoire attributed to vesicle-mediated communication. Large ageing neutrophil-derived vesicles, or LAND-Vs, add an anti-inflammatory dimension: they control complement activation and facilitate the resolution of inflammation, revealing that large vesicles can dampen immune responses as well as provoke them.

Beneath this diversity lies a set of shared physical and biochemical principles that the review dissects with technical precision. Membrane budding and scission require the coordination of actomyosin contractility, hydrostatic pressure and lipid remodelling. The transbilayer distribution of phospholipids emerges as a recurring regulatory node: flippases maintain lipid asymmetry, while scramblases such as TMEM16F collapse it in a calcium-dependent manner, exposing phosphatidylserine on the outer leaflet and promoting both vesicle release and the engulfment signals that mark apoptotic material for clearance. Disruption of flippase localisation in C. elegans increases extracellular vesicle budding, demonstrating that lipid asymmetry actively suppresses vesiculation in healthy membranes. Protein crowding at the membrane, tetraspanin microdomains, lipid rafts and caveolin-dependent dynamics each contribute to curvature generation at specific sites, while the ESCRT machinery contributes its membrane-scission capabilities to several of these pathways.

Cargo sorting into large vesicles follows equally mechanistic rules. The ARF6–Exportin-5 axis delivers pre-microRNA cargo into tumour microvesicles, Cdc42 acts as a regulatory node for microvesicle biogenesis, and RNA-binding proteins govern which transcripts are packaged. Zipcode-like sequence elements enrich specific mRNAs in microvesicles, and integrin pairing with extracellular matrix proteins determines where migrasomes form on retraction fibres. Delivery to recipient cells proceeds through clathrin-independent endocytosis and macropinocytosis, although the review is careful to note that the field still lacks definitive experimental support for functional cargo transfer in many contexts, a caution that reflects growing scrutiny of the extracellular vesicle cargo-transfer hypothesis.

The pathological implications are broad and, in several cases, already translating toward clinical applications. In cancer, large vesicles transfer oncogenic receptors, promote angiogenesis through CD147 and VEGF signalling, carry retrotransposon elements and amplified oncogene sequences, and mediate immune evasion through vesicle-associated PD-L1, which Epstein–Barr virus LMP1 enhances. In neurodegeneration, microglia convert aggregated amyloid-beta into neurotoxic forms through microvesicle shedding, while macrophage-derived migrasomes activate complement-dependent blood–brain barrier damage in cerebral amyloid angiopathy and promote paracrine senescence in ageing brain. Inflammation, thrombosis and kidney injury each feature large-vesicle mechanisms, with urinary podocyte-derived migrasomes emerging as early indicators of glomerular damage and plasma apoptotic bodies serving as non-invasive biomarkers of apoptosis in ischemic stroke.

Methodological rigour occupies a central place in the review’s argument. The authors catalogue the technologies now enabling multidimensional characterisation, from cryo-electron microscopy and super-resolution structured illumination microscopy to nanoparticle tracking analysis, tunable resistive pulse sensing, asymmetric flow field-flow fractionation and microfluidic affinity capture. Deep-learning platforms for automated detection of vesicle exocytosis and self-supervised image enhancement for long-term subcellular recording are extending what live imaging can reveal. Yet the review is equally candid about pitfalls: fluorescent lipophilic dyes can confound uptake studies, isolation methods such as ultracentrifugation and tangential flow filtration yield different preparations, and loss-of-function studies and mechanistic analyses must be appropriately integrated to ensure rigour and reproducibility. Engineered migrasomes that serve as thermally stable vaccination platforms hint at the therapeutic horizon, but the authors stress that biodistribution depends on cell source, administration route and targeting ligands, and that the field’s progress will depend on pairing new tools with the disciplined standards set out in the MISEV2023 framework. What emerges is a portrait of a maturing discipline: one in which the largest and most structurally complex members of the extracellular vesicle family are finally being studied with the systematic attention their biology demands.

Subject of Research: Subtypes, biogenesis and functions of large extracellular vesicles

Article Title: Towards a systematic understanding of the diverse subtypes, biogenesis and functions of large extracellular vesicles

Article References: Huang, Y., Xie, R., Ma, J., & Yu, L. (2026). Towards a systematic understanding of the diverse subtypes, biogenesis and functions of large extracellular vesicles. Nature Reviews Molecular Cell Biology. https://doi.org/10.1038/s41580-026-01021-8

Image Credits: AI Generated

DOI: 10.1038/s41580-026-01021-8

Keywords: large extracellular vesicles, migrasomes, apoptotic bodies, microvesicles, large oncosomes, exophers, blebbisomes, mitophers, plasma membrane budding, tetraspanins, extracellular vesicle biogenesis, cell-cell communication