Cross-species cell interaction

[bioquest]

Not sure what the technical term for that in but could you inject mice cells (heart, liver etc) into humans without killing/harming the human?

 

[hypatia]

Xenotransplantation is the word used when they transplant animal organs/tissue into humans. While some organs like heart valves from pigs have been used with quite a bit of sucess, they are chemically treated first to kill any pig cells.
There has been a lot of studies with animal transplants, most with major setbacks, infection rates seem very high. The FDA has banned non-human primate transplants, here in the USA. There is a known risk of cross-species infection.
Any cells your body detects as "not belonging" will be attacked by your immune system.

 

[bioquest]

okay but could you use immune-rejection drugs, immunosuppressants, something to stop the mouse cells in the human body from being attacked? Could you transplant liver cells from another species (specifically a mouse) into a human or could you definately not? How long ill the immune system take to attack the cells?

So, you could receive something from a mouse or other animal, as long as the mouse or other animal cells were deleted? But if the mouse or other animal cells were what was giving you the effect that would be useless right?

 

[hypatia]

It would be very useless. Rejection starts with in 72 hours. You would half to use so much anti-rejection drugs, that the human would more then likely die of secondary infections, which is often the case, even in human to human transplants.

 

[bioquest]

Does rejection of the cells from a different species (not an organ, but just cells) start after 72 hours? How soon before the cells/not the organ get rejected/destroyed? Does that happen as soon as they start to interact with the body?

thanks
(not starting anymore threads)

 

[hypatia]

Individuals will vary on the amount of time, depending on their immune system. Rejection can start within hours and up to 72 hours later. The body pretty much views all the invading cells the same, it will boost the white blood cell count, depending on its need.

 

[bioquest]

I guess I thought that if the mouse liver cells were given to a human the human might be able to regenerate since I read this article (haven't verified everything in it) but stem cells mutate & degrade with time anyways right and they're not sure what is responsible for the abiitity to regenerate? and the mice can't regenerate/regrow their brains anyway so I am not so interested in it anymore if it can't stop brain degeneration

It's a miracle: mice regrow hearts SCIENTISTS
have created "miracle mice" that can regenerate amputated limbs or
damaged vital organs, making them able to recover from injuries that
would kill or permanently disable normal animals.The experimental animals are unique among mammals in their ability to regrow their heart, toes, joints and tail. And
when cells from the test mouse are injected into ordinary mice, they
too acquire the ability to regenerate, the US-based researchers say. Their
discoveries raise the prospect that humans could one day be given the
ability to regenerate lost or damaged organs, opening up a new era in
medicine. Details of the research will be presented next week
at a scientific conference on ageing titled Strategies for Engineered
Negligible Senescence, at Cambridge University in Britain. The
research leader, Ellen Heber-Katz, professor of immunology at the
Wistar Institute, a US biomedical research centre, said the ability of
the mice at her laboratory to regenerate organs appeared to be
controlled by about a dozen genes. Professor Heber-Katz says
she is still researching the genes' exact functions, but it seems
almost certain humans have comparable genes. "We have
experimented with amputating or damaging several different organs, such
as the heart, toes, tail and ears, and just watched them regrow," she
said. "It is quite remarkable. The only organ that did not grow back was the brain. "When
we injected fetal liver cells taken from those animals into ordinary
mice, they too gained the power of regeneration. We found this
persisted even six months after the injection." Professor
Heber-Katz made her discovery when she noticed the identification holes
that scientists punch in the ears of experimental mice healed without
any signs of scarring in the animals at her laboratory. The
self-healing mice, from a strain known as MRL, were then subjected to a
series of surgical procedures. In one case the mice had their toes
amputated -- but the digits grew back, complete with joints. In
another test some of the tail was cut off, and this also regenerated.
Then the researchers used a cryoprobe to freeze parts of the animals'
hearts, and watched them grow back again. A similar phenomenon was
observed when the optic nerve was severed and the liver partially
destroyed. The researchers believe the same genes could confer
greater longevity and are measuring their animals' survival rate.
However, the mice are only 18 months old, and the normal lifespan is
two years so it is too early to reach firm conclusions. Scientists
have long known that less complex creatures have an impressive ability
to regenerate. Many fish and amphibians can regrow internal organs or
even whole limbs. The Sunday Times
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