Ionizing radiation modifies immune-related molecular profiles of tumor-derived exosomes

Background Exosomes are microvesicles (30-100nm) released from living cells that shuttle and transfer selected cellular biomolecules, including cytokines, cell surface molecules, growth factors, mRNA, and miRNA. Tumor-derived exosomes (TEX) allow for a sophisticated means of communication with a variety of cells, including immune cells, within the tumor microenvironment. Ionizing radiotherapy (RT) promotes anti-tumor immune responses by promoting uptake of tumor antigens by dendritic cells and by enhancing antigen presentation to activate effector T cells. We hypothesized that TEX released from irradiated tumors may play a role in altering the susceptibility of tumor cells to immune-mediated rejection.