Viruses and Extracellular Vesicles: Special Issue, 2020, with Thirteen Articles by Chioma M. Okeoma

The discovery of extracellular vesicles (EVs) dates back to the early 1940s, when Erwin Chargaff and Randolph West showed that platelet-free plasma contains coagulation components that pellet upon high-speed (31,000× g) centrifugation [...].

groups used clinical samples or cultured cell lines to address the crosstalk between EV-associated viral and host proteins from a basic virology perspective.
In their study, Ishikawa et al. used transcriptome analysis to reveal the mRNA profile of milk-derived EVs isolated from Bovine Leukemia Virus-Infected Cattle [9]. McGowan et al., in their pilot study, evaluated the enrichment profile of EV-associated miRNAs from the blood of HEV-and HCV-infected patients [10]. These transcriptomic studies from the Inoshima [9] and Petrik [10] groups are great resources to the EV community as they provide information on the RNA biotypes associated with EVs in different mammalian body fluids under different disease conditions.
In addition to the primary research articles above, excellent reviews by different investigators summarize a wide array of studies on functional effects of EVs and mechanistic insights regulating EV-mediated roles. The review by Alqatawni et al., from the Daniel group, focused on the role of EVs in HIV infection and wound healing. The group summarized published evidence of the involvement of EVs in coagulation, inflammation, proliferation, and extracellular matrix remodeling, all of which are processes involved in wound healing that may be applicable to HIV and other viruses [11]. Insights into the role of EVs in viral replication, pathogenesis, antiviral response, and therapeutic interventions were summarized by Kumar et al., from the Santosh Kumar group [12], and Bello-Morales et al., from the López-Guerrero group [13]. The review by Reyes-Ruiz et al. from the del Ángel group focused on the potential role of EVs in flavivirus dissemination and transmission from the insect vector to host cells [14]. These reviews describe current knowledge about the involvement of EVs in viral pathogenesis and highlight the potential of EVs in the treatment of viral infections.
Additionally, Simone Giannecchini summarized published evidence on the mechanisms by which polyomaviruses (PyVs) exploit the EV delivery system during infection [15]. The investigator proposes that the association of PyV miRNAs with EVs in body fluids may be suggestive of a potential PyV persistence. In their review, Giannessi et al. discussed the state of the art of the studies on the relationship between EVs and various viruses including HIV, HCV, and SARS viruses [16]. This review from the Affabris group [16] placed the potential involvement of EVs in the pathogenesis of SARS viruses in a historical framework with the knowledge of well-known EV-HIV and EV-HCV interactions. To cap this edition of SI, Kutchy et al., from the Buch group, used the interaction between EVs and HIV, HTLV, Zika, CMV, EBV, HepB, HepC, JCV, and HSV to discuss the potential roles of EVs in virus-mediated neurodegenerative diseases and how EVs and their cargos may serve as biomarkers and therapeutic vehicles for viral infections [17].
Combining all the studies published in this SI edition, a theme that echoes the involvement of EVs in the pathogenesis of various viruses emerges. Also evident is the usefulness of EVs in the development of biomarkers and therapeutic strategies against various viruses.
I would like to end by acknowledging everyone that contributed to the success of this SI-including all the authors, editors, reviewers, as well as scientists and researchers of primary articles in our reviews. I am encouraging the academic, scientific, and medical communities to join the virology and EV communities in reading these articles.

Conflicts of Interest:
The author declare no conflict of interest.