Using Borrowed T Cells to Fight Cancer Shows Promise
Healthy T cells from a donor were able to recognize cancer cells that patients’ T cells were not able to.
Findings from a recent study suggest that using one patient’s immune cells in a second patient may potentially allow the cells to recognize and fight tumors even if their own immune system cannot.
According to the study published by Science, researchers found that adding DNA from cancer cells into immune stimulating cells from healthy donors created a response in their immune cells. By inserting the targeted components from the donor cells into the immune cells of the patient with cancer, their immune cells were able to recognize the cancer cells again.
Two main causes that prevent the immune system from fighting cancer are: the immune cells are controlled by brakes that can interfere with their function, and sometimes the immune cells cannot recognize the cancer cells. Researchers tested the borrowed immune system method to determine whether the cells could detect cancer cells in the patient.
T cells check all cells to see whether there are any foreign protein fragments on the cell surface that are not supposed to be there. Once these fragments are identified, the T cells then kill the foreign, aberrant cells.
Cancer cells can display faulty proteins, or they can display neo-antigens on their surface.
The researchers mapped all possible neo-antigens on the surface of melanoma cells from 3 patients. Researchers found a large number of different neo-antigens and then attempted to match the neo-antigens to the patients’ T cells, but most went unnoticed.
However, researchers discovered that donor T cells are able to detect many of the neo-antigens that could not be detected by the patients’ T cells.
"In a way, our findings show that the immune response in cancer patients can be strengthened; there is more on the cancer cells that makes them foreign that we can exploit. One way we consider doing this is finding the right donor T cells to match these neo-antigens,” said researcher Ton Schumacher, PhD. "The receptor that is used by these donor T-cells can then be used to genetically modify the patient's own T cells so these will be able to detect the cancer cells."
Researchers concluded that more research needs to be performed, but they are hopeful this could be a new method for cancer treatment.
"Our study shows that the principle of outsourcing cancer immunity to a donor is sound. However, more work needs to be done before patients can benefit from this discovery. Thus, we need to find ways to enhance the throughput,” said researcher Johanna Olweus, MD, PhD. “We are currently exploring high-throughput methods to identify the neo-antigens that the T cells can "see" on the cancer and isolate the responding cells. But the results showing that we can obtain cancer-specific immunity from the blood of healthy individuals are already very promising.”