The immune system relies on an intricate network of alarm bells, targets and safety brakes to determine when and what to attack. The new results suggest that scientists may now be able to combine DNA sequencing data with their knowledge of the triggers and targets that set off immune alarms to more precisely develop vaccines and other immunotherapies for cancer.
“We already have ways to identify specific targets for immunotherapy, but they are technically challenging, extremely labor-intensive and often take more than a year to complete,” says senior author Robert Schreiber, PhD, the Alumni Professor of Pathology and Immunology at the School of Medicine and co-leader of the tumor immunology program at the Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine. “These difficulties have stood in the way of developing personalized immunotherapies for cancer patients, who often require immediate care for their disease. To our knowledge, this is one of the first studies to show that the faster methods provided by DNA sequencing can help. That opens up all kinds of exciting possibilities.” Scientists have long maintained that the immune system can recognize cancer as a threat either on its own or with the help of vaccines or other immunotherapeutic treatments, which help alert the immune system to the danger posed by cancers. Once the cancer is recognized, the immune system should develop the capacity to attack growing cancer cells until either the tumor is eradicated or the immune system's resources are exhausted. Schreiber and his colleagues have shown that interactions between the immune system and cancer are more complex. Their theory, called cancer immunoediting, suggests that some of the mutations in tumor cells are very easy for the immune system to recognize as a threat. If the immune system detects these mutations in cancer cells, it attacks until they are destroyed. At that point, the cancer may be eliminated. But it's also possible that the cancer can be “edited” by the immune system, resulting in the removal of all the cells containing the critical easily recognized mutations. The remaining tumor cells can continue to grow or enter into a period of dormancy where they are not destroyed but are held in check by the immune system.