A new method for fighting ‘cold’ tumors
Source: www.eurekalert.org Author: news release University of Colorado Anschutz Medical Campus Not all cancerous tumors are created equal. Some tumors, known as "hot" tumors, show signs of inflammation, which means they are infiltrated with T cells working to fight the cancer. Those tumors are easier to treat, as immunotherapy drugs can then amp up the immune response. "Cold" tumors, on the other hand, have no T-cell infiltration, which means the immune system is not stepping in to help. With these tumors, immunotherapy is of little use. It's the latter type of tumor that researchers Michael Knitz and radiation oncologist and University of Colorado Cancer Center member Sana Karam, MD, PhD, address in new research published this week in the Journal for ImmunoTherapy of Cancer. Working with mouse models in Karam's specialty area of head and neck cancers, Knitz and Karam studied 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," Karam says. She and her team found that regulatory T cells (Tregs), a specialized T cell type that suppresses immune response, are essentially telling the T cells to stop fighting the cancer. "Tregs normally serve as an important balance in a healthy immune system," Knitz says. "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 [...]