HIV virus behind leukemia cures at Children's Hospital of Philadelphia

Seven-year-old Emily Whitehead received a lot of attention last year when a gene therapy engineered at the University of Pennsylvania cured her of leukemia. At the time, Emily was one of 10 patients who received the T cell therapy that uses a patient's own healthy T cells infected with a virus to attack the cancer cells.

What's really interesting about the therapy is that it uses the HIV virus. How is that possible?

"The virus has been engineered so that it can't cause disease anymore, but it still retains the ability to reprogram the immune system so that it will now attack cancer cells," says Carl H. June, MD from the University of Pennsylvania.

The new cells have been nicknamed "serial killer cells," and rightfully so. These modified cells can kill more than 1,000 different tumor cells.

Check out the video below for more about Emily Whitehead and how the T cell gene therapy works.