Proceedings of the 2017 ISEV symposium on "HIV, NeuroHIV, drug abuse, & EVs"

A brief history of nearly EV-erything - The rise and rise of extracellular vesicles

Extracellular vesicles (EVs) are small cargo-bearing vesicles released by cells into the extracellular space. The field of EVs has grown exponentially over the past two decades; this growth follows the realisation that EVs are not simply a waste disposal system as had originally been suggested by some, but also a complex cell-to-cell communication mechanism. Indeed, EVs have been shown to transfer functional cargo between cells and can influence several biological processes. These small biological particles are also deregulated in disease. As we approach the 75th anniversary of the first experiments in which EVs were unknowingly isolated, it seems right to take stock and look back on how the field started, and has since exploded into its current state. Here we review the early experiments, summarise key findings that have propelled the field, describe the growth of an organised EV community, discuss the current state of the field, and identify key challenges that need to be addressed.

Biogenesis, physiological functions and potential applications of extracellular vesicles in substance use disorders

Substance use disorder (SUD) is a growing health problem that affects several millions of people worldwide, resulting in negative socioeconomic impacts and increased health care costs. Emerging evidence suggests that extracellular vesicles (EVs) play a crucial role in SUD pathogenesis. EVs, including exosomes and microvesicles, are membrane-encapsulated particles that are released into the extracellular space by most types of cells. EVs are important players in mediating cell-to-cell communication through transfer of cargo such as proteins, lipids and nucleic acids. The EV cargo can alter the status of recipient cells, thereby contributing to both physiological and pathological processes; some of these play critical roles in SUD. Although the functions of EVs under several pathological conditions have been extensively reviewed, EV functions and potential applications in SUD remain less studied. In this review, we provide an overview of the current knowledge of the role of EVs in SUD, including alcohol, cocaine, heroin, marijuana, nicotine and opiate abuse. The review will focus on the biogenesis and cargo composition of EVs as well as the potential use of EVs as biomarkers of SUD or therapeutic targets in SUD.

Extracellular Vesicles in Smoking-Mediated HIV Pathogenesis and their Potential Role in Biomarker Discovery and Therapeutic Interventions

In the last two decades, the mortality rate in people living with HIV/AIDS (PLWHA) has decreased significantly, resulting in an almost normal longevity in this population. However, a large portion of this population still endures a poor quality of life, mostly due to an increased inclination for substance abuse, including tobacco smoking. The prevalence of smoking in PLWHA is consistently higher than in HIV negative persons. A predisposition to cigarette smoking in the setting of HIV potentially leads to exacerbated HIV replication and a higher risk for developing neurocognitive and other CNS disorders. Oxidative stress and inflammation have been identified as mechanistic pathways in smoking-mediated HIV pathogenesis and HIV-associated neuropathogenesis. Extracellular vesicles (EVs), packaged with oxidative stress and inflammatory agents, show promise in understanding the underlying mechanisms of smoking-induced HIV pathogenesis via cell-cell interactions. This review focuses on recent advances in the field of EVs with an emphasis on smoking-mediated HIV pathogenesis and HIV-associated neuropathogenesis. This review also provides an overview of the potential applications of EVs in developing novel therapeutic carriers for the treatment of HIV-infected individuals who smoke, and in the discovery of novel biomarkers that are associated with HIV-smoking interactions in the CNS.

Strategies for the use of Extracellular Vesicles for the Delivery of Therapeutics

Extracellular vesicles (EVs) are nanosized, membrane-bound vesicles released from eukaryotic and prokaryotic cells that can transport cargo containing DNA, RNA, lipids and proteins, between cells as a means of intercellular communication. Although EVs were initially considered to be cellular debris deprived of any essential biological functions, emerging literature highlights the critical roles of EVs in the context of intercellular signaling, maintenance of tissue homeostasis, modulation of immune responses, inflammation, cancer progression, angiogenesis, and coagulation under both physiological and pathological states. Based on the ability of EVs to shuttle proteins, lipids, carbohydrates, mRNAs, long non-coding RNAs (lncRNAs), microRNAs, chromosomal DNA, and mitochondrial DNA into target cells, the presence and content of EVs in biofluids have been exploited for biomarker research in the context of diagnosis, prognosis and treatment strategies. Additionally, owing to the characteristics of EVs such as stability in circulation, biocompatibility as well as low immunogenicity and toxicity, these vesicles have become attractive systems for the delivery of therapeutics. More recently, EVs are increasingly being exploited as conduits for delivery of therapeutics for anticancer strategies, immunomodulation, targeted drug delivery, tissue regeneration, and vaccination. In this review, we highlight and discuss the multiple strategies that are employed for the use of EVs as delivery vehicles for therapeutic agents, including the potential advantages and challenges involved. Graphical abstract.