A study led by investigators at Weill Cornell Medicine has found that activated T cells secrete extracellular vesicles (EVs) containing DNA, which can enter other immune and tumor cells to stimulate the body’s defense systems. Preclinical experiments showed that this vesicle-associated DNA could be useful therapeutically, boosting T cell attacks against tumors that otherwise evoke little or no immune response. Studies in live mice showed that these activated T cell-derived-EVs (AT-EVs) enhanced antigen processing and presentation (APP) in tumor cells and dendritic cells (DCs) across different immunologically cold tumors. The ATEVs also synergized with immune checkpoint inhibitors (ICIs) to trigger antitumor immunity and hold back tumor growth. The discovery extends the scientific understanding of the immune system, identifies a new strategy for boosting immunity against cancers, and potentially offers a new tool for delivering genetic payloads to other cells. “These findings reveal a natural mechanism for treating immunologically silent tumors and other diseases that stem from insufficient immune surveillance,” said David Lyden, MD, PhD, the Stavros S. Niarchos professor in pediatric cardiology and a member of the Gale and Ira Drukier Institute for Children’s Health and the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine. Lyden is co-senior author of the researchers’ published paper in Cancer Cell, titled “Activated T cell extracellular vesicle DNA transfer enhances antigen presentation and anti-tumor immunity,” in which they stated, “We uncover a mechanism whereby activated T cell-derived extracellular vesicles (ATEVs) drive a positive feedback loop that enhances antigen presentation and immune responses…
