A study led by University of Tasmania researchers Cesar Tovar and Gregory Woods has shown that immunotherapy can cure Tasmanian devils (Sarcophilus harrisii) of the devil facial tumor disease. The findings are published in the journal Scientific Reports.
Young Tasmanian devil. Image credit: Keres H. / CC BY-SA 4.0.
Tasmanian devils are the largest carnivorous marsupial in the world, reaching 2.6 feet (80 cm) in length and weighing up to 31 pounds (14 kg).
They display significant aggression toward one another, which often involves biting on the face.
This sometimes transmits Tasmanian devil facial tumor disease (DFTD), a nearly 100% fatal and transmissible cancer first detected in northeastern Tasmania in 1996.
“DFTD is a transmissible Schwann cell cancer that has decimated the Tasmanian devil population,” the researchers said.
“Since its recognition in the far northeast of Tasmania in 1996, the disease has spread over most of the devils’ natural range.”
“It has been estimated that more than 80% of the devil population has been killed by DFTD.”
“Conservation efforts are in place to protect this species, including the establishment of an insurance population. The objective is to reintroduce a robust and genetically diverse population into the wild. This can only be achieved if these devils are protected from DFTD, hence the urgent need for a vaccine.”
Prof. Woods, Dr. Tovar and their colleagues used immunotherapy on devils with a golf-ball sized tumors and then observed the tumors gradually shrinking and disappearing over three 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,” Prof. Woods said.
Building a good understanding of the devil’s immune system, which goes hand in hand with the development of a vaccine, involves years of painstaking laboratory work. 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.
“The latest work underlined that the devil’s immune system is its best ally against DFTD,” Prof. Woods said.
“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.”
“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,” Dr. Tovar said.
“Our research shows that a DFTD vaccine is feasible. We are focusing our efforts on developing strategies to improve the devils’ response to immunization.”
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Cesar Tovar et al. 2017. Regression of devil facial tumour disease following immunotherapy in immunised Tasmanian devils. Scientific Reports 7, article number: 43827; doi: 10.1038/srep43827
