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Life Sciences => Cells, Microbes & Viruses => Topic started by: scientizscht on 15/06/2019 23:33:28

Title: How can prions be transmitted via ingestion or inhalation?
Post by: scientizscht on 15/06/2019 23:33:28

Prions are proteins and it seems not very small ones.

How do they transmit through ingestion and inhalation and how do they cross the blood brain barrier?

Title: Re: How can prions be transmitted via ingestion or inhalation?
Post by: evan_au on 16/06/2019 00:21:13

I have heard of prions being infectious via the digestive system.
- I can imagine that they could bypass the digestive system if they get in via a blood transfusion, during surgery or even a cut in the skin
- I have heard suggestions that prions may be transmitted via optometrists eye-pressure measuring instruments, since there have been traces of prions discovered in the tears of infected individuals, and perhaps they could infect the nerves of the cornea.
- But inhalation seems unlikely, unless the prions were aerosolised (eg in an abattoir); but there have been experiments done on this route...

Your digestive system is very good at breaking down proteins into their constituent amino acids.
- However, prions are not individual proteins, but a polymer of misfolded protein, forming long strings or tangles which would make it difficult for digestive enzymes to attack.
- Presumably, ulcers or other breaks in the stomach lining could allow them into the nervous system or bloodstream.

See: https://en.wikipedia.org/wiki/Prion#Transmission