Journal Article

Differential fates of biomolecules delivered to target cells via extracellular vesicles

Kaspar, Roger L., Butte, Manish J., Hardy, Jonathan W., Matin, A. C., Wang, Andrew, Frimannson, Daniel Omar, Sylvester, Matthew D., Bronsart, Laura, Bachmann, Michael H., Schmidt, Tobi L., Contag, Christopher H., Kanada, Masamitsu

2015

Overview

Significance Extracellular vesicle (EV)-mediated transfer of macromolecules may play a key role in cellular communication and may have utility in directed molecular therapies. In addition, the EV packaged biomolecules in serum may have potential for diagnosing cancer and determining its likelihood of metastasis. EVs are heterogeneous and there are many outstanding questions associated with biogenesis, uptake, and the fate of transferred molecules in recipient cells. In fact, the function, characterization, and even the nomenclature of EVs are being refined. Here we aimed to improve the functional characterization of EVs, and observed that only microvesicles (MVs), but not exosomes, can functionally transfer loaded reporter molecules to recipient cells, largely by delivering plasmid DNA. Our data show that exosomes and MVs are structurally and functionally distinct. Extracellular vesicles (EVs), specifically exosomes and microvesicles (MVs), are presumed to play key roles in cell–cell communication via transfer of biomolecules between cells. The biogenesis of these two types of EVs differs as they originate from either the endosomal (exosomes) or plasma (MVs) membranes. To elucidate the primary means through which EVs mediate intercellular communication, we characterized their ability to encapsulate and deliver different types of macromolecules from transiently transfected cells. Both EV types encapsulated reporter proteins and mRNA but only MVs transferred the reporter function to recipient cells. De novo reporter protein expression in recipient cells resulted only from plasmid DNA (pDNA) after delivery via MVs. Reporter mRNA was delivered to recipient cells by both EV types, but was rapidly degraded without being translated. MVs also mediated delivery of functional pDNA encoding Cre recombinase in vivo to tissues in transgenic Cre-lox reporter mice. Within the parameters of this study, MVs delivered functional pDNA, but not RNA, whereas exosomes from the same source did not deliver functional nucleic acids. These results have significant implications for understanding the role of EVs in cellular communication and for development of EVs as delivery tools. Moreover, studies using EVs from transiently transfected cells may be confounded by a predominance of pDNA transfer.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Animals / Apoptosis / Biological Sciences / Biological Transport - genetics / Biosynthesis / Cell Communication / Cell Membrane - metabolism / Cells / Deoxyribonucleic acid / DNA / DNA - chemistry / Exosomes - chemistry / Flow Cytometry / Gene Silencing / Genes, Reporter - genetics / HEK293 Cells / Humans / Integrases - metabolism / Lipids - chemistry / Macromolecular Substances - chemistry / Mice / Mice, Transgenic / Microscopy, Atomic Force / Microscopy, Confocal / Microscopy, Fluorescence / Molecules / Nucleic acids / Phosphatidylserines - chemistry / Plasma / Plasmids / PNAS Plus / Polyethylene Glycols - chemistry / Protein expression / Ribonucleic acid / RNA / RNA, Messenger - metabolism / Tetraspanin 30 - chemistry