A New Weapon in the War Against Cancer
The human body was designed with a built-in defense force, your immune system. If you imagine the immune system as a general coordinating his troops, when your body is threatened, he gives orders to the white blood cells called T cells, to stand at attention poised to fend off foreign invaders – such as malignant cells. When the T cell warrior sees an invader, he raises his weapon and targets that cell for annihilation.
Stanley Riddell knows this battle well. As a cancer researcher, he has spent more than twenty years waging war against the deadly disease. He explains:
Tumors are very clever, and they utilize evasion strategies to limit the effectiveness of the immune response.
Now he is working with his fellow researchers to create longer-lived T cells that are specifically engineered to seek and destroy malignant cells. The scientists are extracting white blood cells from cancer patients, then exposing them to proteins made by tumor cells. They then isolate the few T cells that recognize the tumor proteins, and stimulate the process of cell division. This generates billions of cancer-fighting cells that can be injected back into the patient, where the T cells will ideally make its way to the site of the tumor and destroy it. Riddell explains:
When you see it work, it is so amazing. The bone marrow just goes from being full of leukemia to being in remission, and very large tumors simply melt away.
Unfortunately, T cells die quickly, and if the body’s immune response is not continuous, the cancer will eventually return.
Riddell and his team knew immunity could potentially last a lifetime, in the same way that vaccines provide lifetime immunity to other diseases. They wondered if they were using the wrong variety of T cells, so they tested other types and found that one, a central memory cell, was sustainable over a long period. That provided the starting point for cancer immunotherapy.
Immunotherapy appears to hold promise for various kinds of leukemia, including chemotherapy-resistant acute lymphoblastic leukemia, which afflicts children. It may also provide a cure for breast, ovarian and skin cancers. Riddell’s research may also dovetail with the work of researchers at University of Washington, who are attempting to create a breast cancer vaccine.
We’re really trying to move immunotherapy with central memory T cells into the clinic quickly. We are excited by the potential for success and believe that this therapy can be applied to several types of cancer.
When it does, millions of lives will be saved.