His bold theory: An infection, whether an inflamed cut or a bad cold, seemed to switch the immune system into high gear, spurring it to attack everything in sight—including malignant tumors. But could science replicate the effect in a drug? Nope. Not for more than a century, anyway. The shift begins. Finally, in recent years, clinical trials have revealed the truth—Coley was right all along. When we manipulate the on/off switches of our immune system’s fiercest fighters, these T cells, as they’re called, seek and destroy metastatic cancer. How well can it work? For some people, dramatically. A variety of T-cell-tweaking regimens—administered through IV drug infusions—are garnering promising results targeting melanoma, leukemia, and kidney, breast, and colon cancers. This is a big deal. Yep, says Yale oncologist Scott Gettinger: “There is no doubt that this is going to change the way we treat cancer.” HOW IMMUNOTHERAPY WORKST cells are the soldiers of your immune system—they fight disease. But cancer suppresses them. With immunotherapy, your doctor can become your T cells’ general. Doctor’s orders: Charge! T cells require two signals to become activated. The first battle cry comes from the T-cell receptor, and the second is via a protein in each T cell known as CD28. Once those signals are received, T cells attack invader cells. Retreat! T cells also have signals that turn them off. Inhibitory molecules in each T cell (one important one is called CTLA4) give the order to fall back. Knowing when to attack and when to back off is the art and science of immunotherapy. Keep fighting! Doctors can now use an antibody that keeps the signals from CTLA4 and other “retreat” proteins temporarily blocked. This allows T cells to keep fighting cancer, when they otherwise might have been suppressed. MORE: 10 Ways To KeepBreast CancerOut Of Your Future
