Stem cells turned into cancer-killing immune cells

[n2doc]

by John Timmer - Aug 13 2013, 11:25am EDT

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—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.

When most people think of immune function, they tend to think of the cells that make antibodies, called B cells. The antibodies they make stick to invading cells and viruses, keeping the invaders from infecting cells and helping to attract immune cells to destroy them. But there's a second branch of the immune system that targets human cells after they become infected. The T cells recognize strange or unfamiliar proteins on the surface of human cells. When they spot them, the T cells attack and kill the infected cell while boosting the rest of the immune response.

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http://arstechnica.com/science/2013/08/stem-cells-turned-into-cancer-killing-immune-cells/