Phagocytes Display Promise as Cancer Treatment Target

Phagocytes are cells best known for their role as immune cells that fight infection. However, recent research has identified broader functions for these cells in major human diseases. Miriam Merad, MD, PhD is an eminent oncologist and immunologist, who combines laboratory studies of phagocytes with a patient-focused perspective to develop new cancer treatments.

What will be the biggest advance in cancer treatment over the next five years?

The landscape of care will be dramatically different in the next five years. It's an exciting time for researchers, but more so for patients. We’re going to see the development of completely new cancer regimens where chemotherapy regimens will be revised to reduce suppressive activity, and combined with novel immunotherapy and likely also targeted therapies.

Why did you study the biology of phagocytes?

During my residency in Hem/Onc I rotated in the allogenic bone marrow transplantation (BMT) unit and witnessed the power of allogeneic BMT to cure patients with leukemia and severe lymphoma which really represent the first success of cancer immunotherapy. The success of BMT convinced me of the potential of immunotherapy to treat cancer. Later during my residency, I met a now very famous cancer immunologist Laurence Zitvogel, who was using phagocytes as vaccines against cancer. As a resident with little time to do research, I became fascinated by these cells and their potential to instruct cancer immunity and this is why I decided to spend my PhD studying these cells.

"We should not be working on the same models that our mentors have been using and should constantly improve them based on the knowledge gained from patients."

Why are phagocytes such a promising target for cancer treatments?

Immunologists have successfully used vaccination to induce anti-tumor immunity, but these successes were very limited. Recently, checkpoint blockade therapy which enhance anti-tumor T cells have had significant clinical success even in tumors that have traditionally not responded to conventional treatment. Now T cells cannot kill a cancer without being instructed to do so. Phagocytes are uniquely able to instruct T cells to kill or not to kill — this enhances phagocytes function and can strongly enhance anti-tumor immunity.

What advice would you give young researchers?

Researchers in the biological sciences should study patients more. We have much to learn from patient lesions and need to bring this knowledge to the lab. In my lab, researchers are encouraged to start with the patient and then decide whether a prominent model is best for attacking the question they want to answer. This is not to say that we need to get rid of the model system. That would be a disaster. Instead, researchers should constantly be revising current models. We should not be working on the same models that our mentors have been using and should constantly improve them based on the knowledge gained from patients.

Learn more from Dr. Merad and others experts, by registering to attend “Phagocytes in Health and Disease” at the Academy’s headquarters on Tuesday, December 4, 2018.