Decoy exosomes as a novel biologic reagent to antagonize inflammation

Abstract

Natalie Duong,1 Kevin Curley,1 Annie Brown,1 Alexander Campanelli,1 Mai Anh Do,1 Daniel Levy,1 Adarsh Tantry,1 Gerard Marriott,2 Biao Lu11Department of Bioengineering, School of Engineering, Santa Clara University, Santa Clara, CA 95053, USA; 2Department of Bioengineering and Tsinghua-Berkeley Shenzhen Institute, University of California at Berkeley, Berkeley, CA 94720, USABackground: Exosomes are ubiquitous naturally secreted stable nanovesicles that can be engineered to target and deliver novel therapeutics to treat a host of human diseases.Methods: We engineered the surfaces of cell-derived nanovesicles to act as decoys in the treatment of inflammation by antagonizing the major proinflammatory cytokine, tumor necrosis factor alpha (TNFα).Results: Decoy exosomes were generated by displaying the TNFα binding domain of human TNF receptor-1 (hTNFR1) on the outer surface of exosomes using stably transfected HEK293 cells. We developed an efficient method to purify the engineered exosomes from conditioned medium based on sequential centrifugation, ultrafiltration, and precipitation. We characterized decoy exosomes using immune-quantification, nanoparticle tracking analysis, and confocal microscopy to confirm that they retain the correct orientation, size, and shape of naturally produced exosomes. We demonstrated the engineered decoy exosomes specifically antagonize activities of TNFα using an inflammatory reporter cell line.Conclusions: Decoy exosomes produced in human cells serve as a novel biologic reagent for antagonizing inflammatory signaling mediated by TNFα.Keywords: Decoy exosomes, Inflammation, CD63, Receptor, TNFα, Drug delivery  

Keywords

• Exosome
• decoy exosome
• TNFα
• inflammation