Devil Facial Tumour Disease Flashcards
(19 cards)
What is DFTD?
A contagious cancer that only effects Tasmanian devils
How is DFTD transmitted?
As an allograft through biting
What does DFTD stand for?
Devil face tumour disease
What is the origin of DFTD?
Arose from a schwann cell in a female Tasmanian devil
What are the two theories for why DFTD is not recognised as foreign?
- DFTD sees as self because they lack diversity at MHC genes
- DFTD evades the immune system by down regulating MHC expression
What is DFTD comparable to?
A skin graft specifically allograft so from the same species
Why could there be such low MHC diversity in Tasmanian devils?
Due to multiple population bottlenecks limiting the pool of MHC alleles
How long has MHC diversity been low in Tasmanian devils?
Thousands of years hence not due to humans
Where is DFTD common in Tasmania?
In the east
Where is DFTD not present in Tasmania?
Northwest
What is one of the things different in the genes of Tasmanian devils that are not impacted by DFTD?
They had polymorphisms which disrupt angiogenesis
What is angiogenesis?
The formation of new blood vessels from exisiting vessels
What is evidence against hypothesis one that its due to lack of diversity at MHC genes?
Tasmanian devils reject allograft which means they can distinguish self from non self
How does DFTD down regulate MHC I expression?
Changes the way DNA is packages preventing transcription of B2m, TAP 1 and TAP 2 meaning DFTD antigens can’t enter the ER
What age of Tasmanian devils are more susceptible to DFTD?
Over 3 years old
What happens to the immune system of Tasmanian devils as the age?
- Decrease in IgM and IgG
- Decrease in lymphocyte abundance
- TCR diversity decreases
How do NK cells respond to DFTD?
They show no cytotoxic response
What are three limitation to DFTD immunotherapy?
- Requires multiple injections
- Difficulty with trapping in remote areas
- Devils are elusive and trap shy
How many strains are there of DFTD?
9-12
