Treg Deactivation Could Boost Immune Response Against 'Cold' Tumors

A team of researchers from the University of Colorado has discovered that regulatory T cells (Tregs) bring T cell responses to a halt in 'cold' tumors—or tumors that don’t show signs of inflammation. They also found that using medication that deactivates Tregs can help boost the immune response in patients with these tumors. Their study was published in Immunotherapy of Cancer. 

Working with mouse models, the scientists looked into the role of T cells in tumor treatment. "What we found is that the cells that normally tell the T cell, 'Hey, here's a tumor—come and attack it,' are being silenced," lead researcher Sana Karam says.

Karam and her team found that Tregs are essentially telling the T cells to stop fighting the cancer. "Tregs normally serve as an important balance in a healthy immune system," collaborator Michael Knitz adds. "They prevent autoimmune disease and put the brakes on the T cells when needed. However, in many tumors, Tregs are too numerous or overly suppressive, bringing the T cell response to a halt."

Karam says the next step in her research is clinical trials she hopes will eventually change the treatment paradigm from surgery and weeks of chemotherapy and radiation to just three sessions of radiation and immunotherapy, then surgery. She is driven to change the standard of care for cold tumors, she explains, because of the difficult effects they have on patients.

"These tumors resemble those in patients who are heavy smokers," she says. "They're very destructive to bone and muscle, infiltrating the tongue, jaw, gum, and lymph nodes. It's horrible. We have very high failure rates with them, and the treatment often involves removing the tongue and weeks of radiation and chemotherapy, only for the patient to fail. I'm confident that we can do better for our patients,” she concludes.