Exosomes That Are Both Antigen-Specific & Carry a Selected Gene-Regulating miRNA Act at the Immune Synapse to Induce APC-Derived Secondary Suppressive Exosomes, A Unique Approach That May Have Treatment Applications in Cancer, Autoimmunity, & Allergy

At the International Society for Extracellular Vesicles 2020 Virtual Annual Meeting (July 20-22) (https://www.eventscribe.com/2020/ISEV/), Philip Askenase, MD, presented a poster (PT09.16) titled “Unique Dual Targeting Antigen-Specific and Delivered Chosen-Gene-Specific Regulating Primary Exosomes Acting at the Immune Synapse to Induce APC-Derived Secondary Effector T Cell Suppressive Exosomes.” Dr. Askenase is Professor of Medicine (Clinical Immunology) at the Yale University School of Medicine in the Section of Rheumatology and Clinical Immunology, and former Chief of Allergy & Clinical Immunology at the Yale University School of Medicine. In the ISEV poster, Dr. Askenase and colleagues report identification of a multi-exosome-APC (antigen-presenting cell) circuit that may be applicable far beyond the skin immunity these scientists study in mice. The researchers show results indicating they have been able to induce therapeutic exosomes that both specifically target a particular antigen on acceptor cells like APCs due to antibody light chains bound to the surface of the exosomes, and also target specific gene functions of the acceptor cells, due to delivery, in the exosome’s cargo, of a selected microRNA (miRNA). This dual antigen-specific (via the surface-bound antibody light chains) and gene-specific (via the exosome-associated selected miRNA) therapy may have applications in the treatment of cancer, autoimmunity, and allergy. In order to demonstrate this capability experimentally,