The Tasmanian devil (Sarcophilus harrisii) is the world’s largest living marsupial carnivore. Devil facial tumour disease (DFTD) is a transmissible cancer that has killed approximately 80% of the devil population. The devil’s immune system fails to recognise foreign DFTD cancer cells and no devil with DFTD has survived.
The inability of the devil’s immune system to reject the transplanted tumours suggests that the tumour cells could be immunologically inert. Immunisation of Tasmanian devils with various formulations of tumour cells and adjuvants has met with limited success. But this limited success has provided evidence that some devils can produce a weak antibody response. These antibodies are providing useful tools to screen for potential tumour antigens.
Immunisation of mice with DFTD tumour cells has provided unequivocal evidence that DFTD tumour cells are immunogenic. When BALB/c and C57Bl mice were injected with viable DFTD tumour cells, neither strain developed a tumour. Immunodeficient NOD/SCID mice always developed tumours when injected with viable DFTD tumour cells. Analysis of the immune response of the BALB/c and C57Bl mice indicated that the presence of the tumour cells did not bias immunity towards a Th1 or Th2 direction, hence the tumour cells are unlikely to have immunomodulatory properties.