- The devil facial tumor disease (DFTD) has spread across most of the Tasmanian devil’s range and has wiped out more than 80 percent of these animals in Tasmania.
- In a new study, researchers could successfully trigger the devil’s immune system to recognise and destroy established DFTD tumours.
- The findings show that a DFTD vaccine is feasible, researchers say.
A type of transmissible cancer has decimated Tasmanian devil populations.
First detected in 1996, the devil facial tumor disease (DFTD) has spread across most of the Tasmanian devil’s range and has wiped out more than 80 percent of these animals in Tasmania. The cancer, which spreads when the devils bite each other’s snouts, kills virtually every devil it infects.
Last year, researchers found that Tasmanian devils (Sarcophilus harrisii) have been evolving resistance to fight the cancer. And now, scientists may have a cure that could prevent the species’ extinction.
After years of laboratory work, researchers have successfully used immunotherapy to shrink and eliminate golf-ball sized tumors on Tasmanian devils. They report their findings in the journal Scientific Reports.
“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 tumour shrink,” Professor Woods of the Menzies Institute for Medical Research, University of Tasmania, said in a statement.
The researchers tested four immunization protocols on nine healthy devils over a span of six years. The team immunised the devils with a variety of cell preparations and exposed them to live DFTD cancer cells, and found that they could successfully trigger the devil’s immune system to recognise 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 immunisation,” said lead author Cesar Tovar of the Menzies Institute for Medical Research.
Only about 10,000 to 25,000 mature Tasmanian devils remain in the wild today, down from an estimated 150,000 individuals in the 1990s. This population collapse is largely due to the infectious cancer. This rapid decline in the devils, which are Tasmania’s top marsupial predators, has resulted in a sharp rise in the activity of feral cats and other invasive species, and a decrease in native mammals.
Ever since DFTD was discovered, scientists have been striving to establish disease-free populations of Tasmanian devils in the wild, which is why the promise of a vaccine is good news for the species, researchers say. Unfortunately, most healthy Tasmanian devils occur only in breeding programs. Before these animals can be released into the wild, they need to be protected against DFTD. An effective vaccine could be the key to their successful introduction.
Citation:
- Tovar, C. et al. Regression of devil facial tumour disease following immunotherapy in immunised Tasmanian devils. Sci. Rep. 7, 43827; doi: 10.1038/srep43827 (2017).