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Author Topic: Do sheep-cells transplanted into humans ever take ?  (Read 300 times)

Offline RD

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Is there any evidence sheep stem-cells transplanted into humans,
#1 survive,  & #2 perform some useful function ,
 ( e.g. as nerves, muscle, endocrine glands, whatever ).

NB: The cells are 100% ovine, not genetically-modified sheep-human hybrid ( like Neilep :)
and the human recipient has a normal immune system , ( no immune-suppression ).


https://wikipedia.org/wiki/Xenotransplantation#Barriers_and_issues
« Last Edit: 12/10/2016 18:36:44 by RD »


 

Online chris

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Re: Do sheep-cells transplanted into humans ever take ?
« Reply #1 on: 12/10/2016 19:07:06 »
In their natural state, stem cells - or any other cell for that matter - from a sheep would not survive in a healthy human. The cells would instantly be recognised by the host immune system as bearing foreign (non-self) antigens on their surfaces, which would trigger a brutal immune response leading to the almost instant destruction of the cells.

The only exception to this might be if such cells were engrafted into an individual lacking an immune response owing to, for instance, a genetic problem such as SCID (severe combined immunodeficiency).

That said, scientists are attempting to engineer replacement tissues that can be grown inside animals like sheep and pigs for subsequent transplant into patients:

https://www.technologyreview.com/s/545106/human-animal-chimeras-are-gestating-on-us-research-farms/
 

Online evan_au

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Re: Do sheep-cells transplanted into humans ever take ?
« Reply #2 on: 12/10/2016 21:29:51 »
There have been trials of transplantation of insulin-secreting cells from non-matched donors, where the cells are enclosed in a porous membrane, allowing oxygen & nutrients in, and allowing insulin & metabolites out, but blocking any direct contact with the immune system. But this is still probably laboratory trials.

If you could do a transplant before the immune system matures in a baby, the thymus would recognize the sheep cells as "self" cells, and the immune system would not attack them.

But this is certainly a very challenging area.

Less challenging is transfer of tissues where the structure is transplanted, but without any living cells. Human cells then populate the transplanted tissues.
 

Offline Semaphore

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Re: Do sheep-cells transplanted into humans ever take ?
« Reply #3 on: 12/10/2016 21:52:59 »
Yeah, makes socialists.
 

Offline RD

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Re: Do sheep-cells transplanted into humans ever take ?
« Reply #4 on: 13/10/2016 01:00:09 »
In their natural state, stem cells - or any other cell for that matter - from a sheep would not survive in a healthy human. The cells would instantly be recognised by the host immune system as bearing foreign (non-self) antigens on their surfaces, which would trigger a brutal immune response leading to the almost instant destruction of the cells.

So the chap in this video, (allegedly a double doctor: PhD&MD), is incorrect when he says sheep-cells are "never" rejected when implanted into humans ...

https://youtu.be/f6wVfkb6UFs?t=30s

His statement sounded bollocks false to me, but I wanted to check that was the case.

xenotransplantation can work if the host does not have an effective immune system,
e.g. if the host was an early fetus, before it's immune-system had developed, or nude mice, which can be host to human cancer cells.
« Last Edit: 13/10/2016 13:28:10 by RD »
 

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Re: Do sheep-cells transplanted into humans ever take ?
« Reply #4 on: 13/10/2016 01:00:09 »

 

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