You know what would be nice? If there were a way for our immune systems to identify cancer cells and just handle them. You know, without cancer patients having to flood their systems with toxic chemotherapy chemicals or by blasting the cancer cells (in addition to a lot of healthy cells) with high-energy radiation. For this reason, the field of immunotherapy is really hot in cancer research these days.
A lot of money has been invested in immunotherapy cancer research over the past few years, and it seems to be paying off. New research suggests we might be closer to having a viable immunotherapy treatment that uses healthy donor immune cells planted with mutated cancer DNA to train a patient's own immune system to fight off their cancer.
Our immune systems have a notoriously difficult time dealing with cancer cells. Under normal circumstances, our immune cells, commonly called T cells, are instructed to scan for proteins on the surface of every cell that identifies it as either healthy and normal, or not. When a T cell comes across a cell bearing a foreign protein fragment, or neo-antigen, the T cell is supposed to destroy it. But sometimes a cancer patient's T cells have a hard time recognizing a cancer cell's protein insignia as foreign and dangerous, so they neglect to flag it for attack by the immune system.
In other cases, a series of "breaks" in the operation of the immune system prohibits T cells from binding to and destroying cancer cells. Most research in immunotherapy focuses on how to help our immune systems better detect and destroy cancer cells, or how to bypass these "brakes."
Researchers at the the Netherlands Cancer Institute and the University of Oslo have been looking into whether immune cells can be outsourced — whether another person's T cells might be better at detecting and flagging cancer cells than the patient's own. In a proof of principle study, all the possible neoantigens on the melanoma cells of three different cancer patients were mapped and then put in the ring with the patient's own T cells. When faced with cells peppered with neoantigens from their own cancer cells, the cancer patient's T cells completely dropped the ball. They had no idea there was anything wrong with those cells.
However, when researchers seeded a healthy donor's T cells with a piece of mutated DNA from the patient's cancer cells and then pitted them against cells from the patient's tumor, the research team discovered the donor T cells had a much better time detecting all the possible neoantigens on the patient's cancer cells than the patient's own T cells.
"Our research opens the possibility to make efficient, cancer-specific immune responses independently of the patient's own immune system," says Johanna Olweus of the Netherlands Cancer Institute. "By outsourcing the immune response to a healthy donor, the patient's weakened immune response can be strengthened in cases where it is insufficient."
The research team is hoping these donated T cells might be able to train the patient's own immune system to detect and destroy their own cancer cells.
"Since it targets cancer-specific mutations, the approach could in principle be tailored to any cancer form," says Olweus. "And for the same reason it is expected to have few side effects. However, it will take more work and resources before this can be translated into therapy."
But 50 years from now, hopefully we'll be telling our grandkids, "Back when I was your age, we used to treat cancer with POISON!" That'll scare them straight.