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Extracell Vesicles Circ Nucleic Acids 2020;1:20-56 I http://dx.doi.org/10.20517/evcna.2020.10 Page 47

E-mail: jericks@gmu.edu
Affiliations:
1 Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, USA.
2 Izon Science (IZON), Medford, MA, USA.
3 American Type Culture Collection (ATCC), Manassas, VA, USA.
4 Systems Biosciences (SBI), Palo Alto, CA, USA.
Abstracts: Since the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) was declared a
pandemic in mid-March of 2020 by the World Health Origination (WHO), laboratories around the
[1]
world started research into diagnostics, therapeutics, and treatments . In recent years, the importance of
extracellular vesicles (EVs) in the pathogenesis of viral infections have been found in the cases of many viral
pathogens including few DNA and RNA viruses including human T-cell leukemia virus-1 (HTLV-1) and
[2,3]
human immunodeficiency virus-1 (HIV-1) . EVs from HIV-1 infected cells on uninfected macrophages
[3]
induces an increase in the proinflammatory cytokines . While EVs from HTLV-1 infected cells on
uninfected recipient cells promoted the localization and cellular contact by cells, this directly influences
[2]
the pathogenesis of HTLV-1 as the virus mainly infects other cells by cell to cell contact . Similar to
retroviruses, coronaviruses are also positive strand RNA viruses, except they replicate in the cytoplasm and
may regulate chromosomal DNA depending on the strain of virus. We have recently began working on
beta- coronaviruses, including OC43 (BSL2 strain) and SARS-CoV-2 (BSL3 strain). Our initial experiments
focus on isolation of EVs away from virions using either an iodixanol gradients or Izon sizing columns.
We have successfully separated the two from one another mainly due to their density and potentially size
differences. We found that EVs from multiple coronaviruses are not infectious and viral particles treated
with UV irradiation are also not infectious. We also have found that coronavirus EVs caused T-cell death,
which may corelate with lymphopenia observed in COVID patients. Along these lines coronavirus EVs can
activate other viral genes (i.e., HIV-1 or HTLV-1) when these genes are integrated into the genome, further
implying that these EVS regulate chromosomal gene expression. Finally, the mechanism(s) of how these
EVs may cause such diverse effects on T-cells and other viral gene expression will be discussed.

REFERENCES
1. Cucinotta D, Vanelli M. WHO Declares COVID-19 a Pandemic. Acta Biomed 2020;91:157-60.
2. Pinto DO, DeMarino C, Pleet ML, et al. HTLV-1 extracellular vesicles promote cell-to-cell contact. Front Microbiol 2019;10:2147.
3. Sampey GC, Saifuddin M, Schwab A, et al. Exosomes from HIV-1-infected cells stimulate production of pro-inflammatory cytokines
through trans-activating response (TAR) RNA. J Biol Chem 2016;291:1251-66.

36. Reduction of the therapeutic dose of silencing RNA by packaging it in extracellular

vesicles via a pre-microRNA backbone

Authors: Ryan Reshke, James A. Taylor, Alexandre Savard, Huishan Guo, Luke H. Rhym, Piotr S.
Kowalski, My Tran Trung, Charles Campbell, Daniel G. Anderson, Derrick Gibbings
E-mail: rreshke@uottawa.ca
Affiliations:
Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada.
The Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA,
USA.
Abstracts: Current delivery vehicles enable less than 1% of silencing RNA (siRNA) cargoes to escape into
the cytoplasm. This necessitates high doses in patients that have demonstrated toxicity and constrained use
of siRNA therapeutics to targets expressed in liver. Small extracellular vesicles (sEVs) are naturally released