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Page 32 Extracell Vesicles Circ Nucleic Acids 2020;1:20-56 I http://dx.doi.org/10.20517/evcna.2020.10

milk exosomes. Hence, peptide targeted, hypoxia-responsive bovine milk exosomes (iHRX) encapsulating
the anticancer drug doxorubicin will decrease cell survival of triple-negative breast cancer cell population.
Doxorubicin has been encapsulated using electroporation and shows encapsulation efficiencies of above
50%. Transmission electron microscopy, atomic force microscopy, and dynamic light scattering have
demonstrated the stability of modified exosomes in normoxic conditions and exosome fragmentation
under concentrations greater than 5 mM glutathione, which directly corresponds to tumor oxygen levels.
Additional studies to confirm the presence of iRGD has been performed indicating strong adhesion to the
avb3 integrin most abundantly found in tumors. Future studies will include testing of iHRX’s toxicity and
cellular internalization in monolayer and three-dimensional cultures prior to in vivo studies.

15. Liver tumor-derived exosomes (small extracellular vesicles) induce macrophage polarity

Authors: Mackenzie J. Burroughs, Gina T. Bardi, Joshua L. Hood
E-mail: joshua.hood@louisville.edu
Affiliations:
Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.
James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA.
Hepatobiology and Toxicology COBRE, University of Louisville, Louisville, KY, USA.
Abstracts:
Our recent data demonstrate that nanoscale tumor-derived small extracellular vesicles (sEVs), otherwise
known as exosomes, induce macrophage (Mϕ) functions. Tumor-associated M1 (proinflammatory) or
M2 (immunosuppressive) Mϕs are pivotal in the progression of inflammation-related cancers such as
hepatocellular carcinoma. However, the ability of liver tumor-derived sEVs to influence Mϕ- related pro-tumor
processes is largely unexplored. Using human HepG2 liver tumor and THP-1 Mϕ models, we investigated
the hypothesis that HepG2-sEVs induce Mϕ polarity, indicative of pro-tumor inflammatory processes.
Preliminary ELISA results revealed a dose dependent increase in production of the proinflammatory M1
cytokine TNF-α and immunosuppressive M2 cytokine IL-10 at a treatment concentration of 0.05 μg sEV
protein/μL. Subsequent ELISA experiments demonstrated batch to batch variations in the induction of IL-
10 by HepG2-sEVs at the 0.05 μg sEV protein/μL dose. In contrast, normal plasma (np) control sEVs did
not increase IL-10 production. TNF-α production was significantly induced by all np-SEV and HepG2-sEV
lots and batches tested. Use of qRT-PCR showed that both np control and HepG2 sEVs favored induction
of M1 polarization factors with HepG2’s also trending toward induction of a few mixed M1/M2 and M2
markers. Overall, HepG2-sEVs induced Mϕ polarity, indicative of pro-tumor inflammatory processes. Future
investigations will explore these processes and derivative therapeutic strategies.
Grant Support: University of Louisville Cancer Education Program (R25-CA134283), The Elsa U. Pardee
Foundation (PI J.L. Hood), University of Louisville Department of Pharmacology and Toxicology Faculty
Start-up funds to J.L. Hood, and UofL Hepatobiology and Toxicology COBRE NIGMS NIH P20GM113226.

16. Small RNA-binding molecules inhibit HIV-1 transcription in CNS latent reservoirs

1
4
1
3
1,2
Authors: Pooja Khatkar , Maria Cowen , Catherine DeMarino , Fardokht A Abulwerdi , Lance A Liotta ,
3
Stuart F.J Le Grice , Fatah Kashanchi 1
E-mail: pkhatkar@masonlive.gmu.edu
Affiliations:
1 Laboratory of Molecular Virology, George Mason University, Manassas, VA, USA.
2 Infections of the Nervous System, NINDS, Bethesda, MD, USA.