Activated immune cells secrete tiny capsules bearing DNA that can enter other immune and tumor cells to stimulate the body’s defense systems, according to a study led by investigators at Weill Cornell Medicine. 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.
Most animal cells secrete tiny capsules known as extracellular vesicles—nanoscale, membrane-bound particles—whose cargo can include proteins, snippets of DNA and other molecules. In the new study, published April 30 in Cancer Cell, the researchers discovered that vesicles secreted by activated T cells —major weapons of the immune system—carry DNA that enters immune cells and nearby tumor cells to enhance the immune response against the tumor. 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.
“These findings reveal a natural mechanism for treating immunologically silent tumors and other diseases that stem from insufficient immune surveillance,” said study co-senior author Dr. David Lyden, 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.









