Newswise — By recruiting the immune system to combat tumor cells, immunotherapy has improved survival rates, offering hope to millions of cancer patients. However, only about one in five people responds favorably to these treatments. With a goal of understanding and addressing immunotherapy’s limitations, researchers at Washington University School of Medicine in St Louis have found that the immune system can be its own worst enemy in the fight against cancer.
In a new study in mice, a subset of immune cells – type 1 regulatory T cells, or Tr1 cells – did its normal job of preventing the immune system from overreacting but did so while inadvertently restraining immunotherapy’s cancer-fighting power. “Tr1 cells were found to be a heretofore unrecognized obstacle to immunotherapy’s effectiveness against cancer,” said senior author Robert D. Schreiber, PhD , the Andrew M.
and Jane M. Bursky Distinguished Professor in the Department of Pathology & Immunology , and director of the Bursky Center for Human Immunology & Immunotherapy at Washington University School of Medicine. “By removing or circumventing that barrier in mice, we successfully reenergized the immune system’s cancer-fighting cells and uncovered an opportunity to expand the benefits of immunotherapy for more cancer patients.
” The study is available in Nature. Cancer vaccines represent a new approach to personalize cancer immunotherapy. Aimed at the mutant proteins specific to a patient’s tumor,.