Prions & TSEs

Question 1

What does TSE stand for

Answer 1

Transmissible spongiform encephalopathies

Question 2

What is TSE in general terms

Answer 2

Non-febrile, degenerative, transmissible, fatal disease affecting the CNS

Question 3

What is the cause of TSE (very general)

Answer 3

Aberrant protein expression - proteins are resistant to proteases

Question 4

What are Koch’s postulates of infection

Answer 4

1 - cause found in sufferers, but not in healthy animals
2 - when isolated from diseased animals and given to healthy susceptible animals, a disease with the characteristic symptoms and clinical outcome should result
3 - it should be possible to reisolate the disease agent from the inoculated animals

Question 5

Prion definition:

Answer 5

A proteinaceous infectious particle that lacks nucleic acid

Question 6

Why was the discovery of prion disease important for medicine in general

Answer 6

It was previously thought that the presence of nucleic acid was needed for infections to be passed/inherited

Question 7

What is the name for the infectious form of the prion protein

Answer 7

PrPsc

Question 8

What is the structure of the PrPsc vs PrPc protein

Answer 8

PrPsc - beta-sheets
PrPc - alpha helices

Question 9

How does PrPsc cause disease

Answer 9

The beta sheets form insoluble fibrils (amyloid!) by H bonding to each other
Accumulation –> plaques –> cell death & neurodegeneration

Question 10

Does the normal form (PrPc) need to be present for prion disease to develop?

Answer 10

Yes

Question 11

Why does PrPc need to be present for the disease to occur?

Answer 11

PrPsc induces PrPc to change conformation