Stem cells turned into cancer-killing immune cells

T cells, colored blue here, move in to attack.

NCI

In addition to fighting off invaders that arrive from outside the body, the immune system is also able to identify cells that have gone bad inside the body. Even though cancer cells look a lot like normal ones, immune cells can often tell the difference—often enough that people who receive long-term treatments of immunosuppressive drugs have a higher incidence of cancer.

But the immune system clearly has its limits, or cancer wouldn't be a problem. Cancer cells evolve ways to avoid detection or use the immune system's own signals to tamp down its activity. A number of researchers have been looking for ways to reestablish the immune system's superiority, boosting it in a way that it once again clears out cancer cells. One option for doing so has been to simply boost the cells that already recognize a tumor by isolating them and growing them in large numbers in culture.

This doesn't consistently work, however, as it can be hard to identify and isolate tumor-specific immune cells. A team of researchers has figured out a way of taking stem cells, converting them into immune cells, and directing them to attack one type of cancer.