The Role of Extracellular Vesicles in Viral Infection and Transmission

Abstract

Extracellular vesicles (EVs) have been found to be released by any type of cell and can be retrieved in every circulating body fluid, namely blood (plasma, serum), saliva, milk, and urine. EVs were initially considered a cellular garbage disposal tool, but later it became evident that they are involved in intercellular signaling. There is evidence that viruses can use EV endocytic routes to enter uninfected cells and hijack the EV secretory pathway to exit infected cells, thus illustrating that EVs and viruses share common cell entry and biogenesis mechanisms. Moreover, EVs play a role in immune response against viral pathogens. EVs incorporate and spread both viral and host factors, thereby prompting or inhibiting immune responses towards them via a multiplicity of mechanisms. The involvement of EVs in immune responses, and their potential use as agents modulating viral infection, will be examined. Although further studies are needed, the engineering of EVs could package viral elements or host factors selected for their immunostimulatory properties, to be used as vaccines or tolerogenic tools in autoimmune diseases.

Lysosomal Exocytosis, Exosome Release and Secretory Autophagy: The Autophagic- and Endo-Lysosomal Systems Go Extracellular

“…Similar findings were reported for poliovirus [115] and zikavirus [116]. Moreover, it has been widely reported that enveloped viruses hijack the endosomal-lysosomal pathway for biogenesis and infection [117]. As a matter of fact, EVs and viruses share common features in their size, biogenesis and uptake and, when released by infected cells, EVs have been demonstrated to contain viral components, such as proteins and genetic material [118].…”

“…The elevated α-synuclein exocytosis promoted α-synuclein deposition and cell death in neighboring neurons [127]. This finding provides a potential link between autophagic dysfunction and the progressive spread of the pathology [117]. In the case of Alzheimer's disease (AD), very early evidence for the role of MVBs in βAPP metabolism was provided by the study by Vingtdeux et al, which showed that βAPP and its catabolic derivatives are secreted in exosomes [62].…”

Introductory Chapter: An Overview to the Extracellular Vesicles

“…The composition of each kind of EV derives from the cell and purpose of the vesicle realized to the media. As such, these vesicles became an important marker for diseases, including cancer, infectious diseases, renal diseases, and diabetes [16][17][18][19][20]. In order to achieve this, EVs must be characterized and analyze their confidence to be candidates for those used by humans.…”

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

“…They are considered as both inter and intra-cellular messengers, able to modify their cargo according to the condition or stimulus affecting the parent cells [31,32], which upon internalization by recipient cells, can modulate the pathophysiological state in those cells [33,34]. EVs play an important role in HIV pathogenesis -either in improving or deteriorating the existing condition; however, the exact role of EVs in HIV pathogenesis is poorly understood [35,36]. Currently, only a handful of studies have investigated the role of EVs in smoking-mediated toxicity in the setting of HIV [37][38][39].…”