An international study involving multiple institutions over 6 years has shown that immunotherapy can cure Tasmanian devils of the deadly devil facial tumor disease (DFTD). The research was led by the University of Tasmania's Menzies Institute for Medical Research with input from the School of Medicine. It also involved the Walter and Eliza Hall Institute of Medical Research, CSL Limited, and the Universities of Sydney, Southampton, Southern Denmark, and Cambridge.
Greg Woods, Ph.D., the leader of the DFTD team at Menzies, said scientists used immunotherapy on devils with a golf-ball sized tumors and then observed the tumors gradually shrinking and disappearing over 3 months. “This is almost a Eureka moment for us because it's the first time we can say for sure that it was the immunotherapy that was making the tumor shrink,” Dr. Woods said.
Building a good understanding of the devil's immune system goes hand in hand with the development of a vaccine. The process is incremental, but with each step scientists are closing in on the disease. This breakthrough is the next step on from work published in 2015 that showed that the devil's immune system was capable of mounting an immune response to DFTD.
Dr. Woods said the latest work underlined that the devil's immune system is its best ally against DFTD. “This is an important step along the way to developing a vaccine to protect against DFTD and potentially for immunotherapy to cure devils of established DFTD,” he said.
“The cancer cell is the ‘infectious’ agent transmitted as an allograft by biting. Animals usually die within a few months with no evidence of antibody or immune cell responses against the DFTD allograft. This lack of anti-tumor immunity is attributed to an absence of cell-surface major histocompatibility complex (MHC)-I molecule expression. While the endangerment of the devil population precludes experimentation on large experimental groups, those examined in our study indicated that immunization and immunotherapy with DFTD cells expressing surface MHC-I corresponded with effective anti-tumor responses,” reported the investigators.
Cesar Tovar, Ph.D., is the lead author on the latest paper (“Regression of Devil Facial Tumour Disease Following Immunotherapy in Immunised Tasmanian Devils”) published in Scientific Reports. He said the results were very encouraging as they confirmed that it was possible to trigger the devil's immune system to recognize and destroy established DFTD tumors. “Our research shows that a DFTD vaccine is feasible. We are focusing our efforts on developing strategies to improve the devils' response to immunization,” Dr. Tovar noted.