Natural mechanism of the body"s defense against cancer discovered

Immune cells are capable of "transferring" special DNA fragments to each other and to tumors, enhancing their ability to recognize and destroy cancer. This revolutionary discovery was made by researchers from Weill Cornell Medical Center. The results of the study were published in the journal Cancer Cell.

The team of scientists established that activated T cells — the main "soldiers" of immune defense — release extracellular vesicles. These are microscopic membrane "capsules" that cells use to exchange signals. Inside these tiny containers, DNA fragments capable of penetrating other cells were discovered.

A series of experiments demonstrated that DNA-containing vesicles are absorbed by both neighboring immune cells and cancer cells themselves. Once inside, they trigger enhanced antigen presentation — the very mechanism by which the immune system recognizes the enemy. The result is impressive: tumors lose their "invisibility" and come under a powerful immune attack.

Under normal conditions, cancer cells actively camouflage themselves, suppressing immune surveillance. However, the discovered mechanism effectively reverses the situation: the vesicles restore the immune system's lost ability to "see" the tumor.

Preclinical trials in animals yielded encouraging results: the administration of vesicles led to slowed tumor growth and massive infiltration of immune cells into them. The effect was observed across several types of cancer — glioblastoma, pancreatic cancer, and triple-negative breast cancer. All of these forms are considered particularly resistant to immunotherapy.

Another important detail: the DNA inside the vesicles turned out not to be a random assortment of genetic material. It is enriched with genes associated with immune function. Additionally, a special enzyme was found on the surface of the vesicles that delivers the genetic cargo directly into the cell nucleus, where it can be temporarily activated.

The authors of the study emphasize that the discovery points to the existence of a natural "amplification loop" of the immune response. T cells do not simply attack the tumor directly — they mobilize the entire immune system by sending genetic signals to their allies.

The research team is currently developing new therapeutic approaches based on the discovered mechanism. It is anticipated that vesicles could be used as a standalone treatment method or in combination with existing immunotherapy regimens.