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Engineered pig organs survive in monkeys
Nature Magazine ^ | 08 December 2003 | HELEN PEARSON

Posted on 12/08/2003 7:13:18 AM PST by PatrickHenry

Genetically modified pig kidneys have survived long after being transplanted into baboons. Researchers hope that this early success may pave the way for animal-to-human organ transplants.

The pigs used in the experiment were engineered to have human-friendly organs in 2002. They lack a key sugar molecule that normally prompts the human and monkey immune system to launch an aggressive and fatal attack on foreign tissues.

Now David Sachs, of Massachusetts General Hospital in Cambridge, and his team have transplanted kidneys from the genetically modified pigs into eight baboons. The new organs enabled the animals to survive for up to 81 days, compared with around 30 days for non-transgenic kidneys.

The results show that, in principle, the genetically engineered pig organs bypass the fierce rejection response, and will perhaps escape attack in the human body too. "It is evidence that rejection can be overcome," agrees transplant immunologist Kathryn Wood of the University of Oxford, UK.

Eighty-one days is around the longest that researchers have extended a baboon's life with a pig organ — although baboon-to-baboon transplants are still more successful. With extra work, "the likelihood is that we'll be able to go much further", Sachs predicts.

The team has yet to publish the experiments, which were carried out in collaboration with Immerge BioTherapeutics in Cambridge, Massachusetts. Sachs presented the findings in October this year to the International Xenotransplantation Congress in Glasgow, UK.

Experts say that the genetically modified pigs may be the most promising development on the long road towards animal-to-human transplants, or xenotransplants. They hope that animal organs could one day make up for the massive shortfall in available human organs such as hearts and kidneys.

Sugar-free

The pigs lack a gene called alpha-1,3-galactosyltransferase, or GGTA1, which adds alpha-1,3-galactose sugar molecules to its cells. Monkeys and humans harbour a pool of ready-made antibodies that instantly recognize this sugar, prompting a rapid and violent rejection, sometimes within minutes.

Researchers have made genetically modified pigs for transplants before, but these animals carried extra genes that suppress this immune response, rather than avoiding it altogether. The animals that Sachs' team used are also miniature pigs, so their organs are roughly the same size as human ones.

Another team, led by David Ayares of Revivicor in Blacksburg, Virginia, has also found preliminary evidence that pig organs engineered to lack GGTA1 can bypass rejection. Revivicor is a spin-off company from PPL Therapeutics, whose researchers created the transgenic pigs.

Safety first

The latest experiments do not give the green light to pig-to-human transplants. Scientists must still overcome other rounds of attack by the immune system, such as the tiny blood clots that killed some of Sachs' baboons.

Sachs' team used other tricks to quell organ rejection in the baboons, including drugs that quieten the immune system. Along with the kidney, the researchers also transplanted pieces of pig thymus, which pump out immune cells that do not attack pig tissues.

There are also numerous safety and ethical hurdles to clear before researchers can consider transplanting organs into humans. One concern is that pig organs could carry unknown viruses. Some people also have ethical objections to the rearing of humanized animals as organ factories.


TOPICS: Culture/Society; Miscellaneous
KEYWORDS: crevolist; evolution; health; healthcare; immunesystem; organtransplant; rejection
A couple of issues here: genetic engineering [oh the horror!], monkeys and humans [Gasp! That reeks of common descent!] both exhibit the same violent rejection to pig transplants, and ... despite these issues, science continues to make progress.
1 posted on 12/08/2003 7:13:21 AM PST by PatrickHenry
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To: *crevo_list; VadeRetro; jennyp; Junior; longshadow; RadioAstronomer; Scully; LogicWings; ...
PING. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]
2 posted on 12/08/2003 7:14:14 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry
They should call that magazine, un-nature.
3 posted on 12/08/2003 7:15:04 AM PST by CJ Wolf
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To: PatrickHenry
I wonder if they're gonna genetically engineer a pig that is all baby back ribs...
4 posted on 12/08/2003 7:15:32 AM PST by Kenton (Hmmm...So this is how this tag line thingie works)
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To: PatrickHenry
Sorry, it must be too early in the morning for me. My first thought upon reading this was: Is the resulting hybred animal called a Punky or a Mig?
5 posted on 12/08/2003 7:17:22 AM PST by Egon (I'll still respect you... I'll respect you even more... Just use more whipped cream...)
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To: PatrickHenry
This explains Hillary
6 posted on 12/08/2003 7:19:32 AM PST by thoughtomator (The U.N. is a terrorist organization)
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To: PatrickHenry
When are we going to get a four assed monkey?
7 posted on 12/08/2003 7:21:01 AM PST by CzarNicky (The problem with bad ideas is that they seemed like good ideas at the time.)
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To: Kenton
I still remember several years ago when a baboon's heart was transplanted into a human....Petah Jennings used the apparent Canadian pronunciation: "Buh-boon"
8 posted on 12/08/2003 7:21:28 AM PST by ErnBatavia (Taglineus Interruptus)
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To: PatrickHenry
science continues to make progress

I think mankind has finally reached maturity.
There will always be a residual supernaturalists to whine,
but their influence is waning.

9 posted on 12/08/2003 7:26:32 AM PST by ASA Vet ("Those who know don't talk, those who talk don't know.")
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To: PatrickHenry
The results show that, in principle, the genetically engineered pig organs bypass the fierce rejection response, and will perhaps escape attack in the human body too. "It is evidence that rejection can be overcome,"

My mother had four separate valve transplants - two pig valve's and two mechanical valve's. She rejected the pig valve after her last surgery.

I hope genetic engineering works and will reduce the rejection rate.

10 posted on 12/08/2003 7:47:18 AM PST by flutters (God Bless The USA)
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To: ASA Vet
There will always be a residual supernaturalists to whine, but their influence is waning.

They'll probably be complaining all over this thread. But they'll all accept an organ transplant if they need one. Provided, of course, that it's been suitably engineered to be successfully transplanted into the related [gasp!] monkey-human family of [ahem!] animals.

11 posted on 12/08/2003 7:52:08 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: Kenton
I wonder if they're gonna genetically engineer a pig that is all baby back ribs...

Now you're talking!

12 posted on 12/08/2003 8:16:13 AM PST by <1/1,000,000th%
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To: PatrickHenry
My first thought is that Western medicine should make as much as possible based on pigs -- transplants, vaccines, pharmaceuticals.
13 posted on 12/08/2003 8:56:34 AM PST by js1138
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To: ASA Vet
This isn't a crevo issue.

And how dare the skeptics voice concern over animal-to-human transplants! What's the worst that could happen? (degredation of the humane genome, death, suffering)

First you give the recipient immunosupressants (e.g., Cyclosporin) and/or steroids, basically rendering their immune system inoperable, then introduce animal organs which may or may not work and which may also contain uniquely-animal viruses that can contaminate the human genome forever. The viruses can 'jump' species barriers and be passed both horizontally (e.g., needles) and vertically (offspring). Furthermore, animal organs weren't designed to support the human respiratory systems. For example, pig kidneys are unable to handle the high levels of uric acid found in the human bloodstream and are also unable to regulate drug levels.

So, no, it's not just creationists who have a problem with the practice, it's everyone who understands the possible side effects and associated effects on the human genome. (course to an evo, what's one bad mutation?)

I think the alternatives (living healthier lifestyles, the utilization of organs taken from deceased humans and intelligently designed mechanical parts) seem more viable. But who knows, if our scientists continue to intelligently design and restructure mature systems and components, we may have a breakthrough!

14 posted on 12/08/2003 9:56:06 AM PST by Michael_Michaelangelo
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To: Michael_Michaelangelo
skeptics voice concern over animal-to-human transplants

I have no problem with skeptics basing their argurments on reality.
They will likely bring up factors which will need to be addressed, and researched.

15 posted on 12/08/2003 10:07:22 AM PST by ASA Vet ("Those who know don't talk, those who talk don't know.")
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To: PatrickHenry
Thanks for the ping!
16 posted on 12/08/2003 12:29:54 PM PST by Alamo-Girl
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To: Alamo-Girl
Some threads just don't attract any interest. Whatcha gonna do?

Didn't want your post to be the last. Too embarrassing. So let it be mine.

17 posted on 12/09/2003 3:48:53 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: PatrickHenry
Novartis did a study a couple of years ago which suggested strongly that the threat of transgenic viruses from xenotransplants was very low, which was one of the common fears about such things.

Might as well make the last post on-topic ;)

18 posted on 12/09/2003 4:00:48 AM PST by general_re (Knife goes in, guts come out! That's what Osaka Food Concern is all about!)
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To: PatrickHenry; general_re
Actually, I've been expecting this thread to explode because there are so many different topics to discuss. The first one that occurs to me is the use of pig engineered organs would be intolerable to all the Muslims. Of course it might also work as a punishment worse than death for one caught in a terrorist attack...
19 posted on 12/09/2003 10:00:09 AM PST by Alamo-Girl
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To: Alamo-Girl
The first one that occurs to me is the use of pig engineered organs would be intolerable to all the Muslims.

Sucks for them. This is why it's really important to read the fine print when shopping for a religion ;)

20 posted on 12/09/2003 10:25:15 AM PST by general_re (Knife goes in, guts come out! That's what Osaka Food Concern is all about!)
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To: PatrickHenry
I've been waiting for this thread to explode, too, but it seems that the word "creation" hasn't been mentioned, so all's quiet for the time being. However, I'm shocked that no one has responded to your "common ancestor" quip.
21 posted on 12/09/2003 10:26:51 AM PST by stanz (Those who don't believe in evolution should go jump off the flat edge of the Earth.)
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To: stanz
I'm shocked that no one has responded to your "common ancestor" quip.

They know by now that I probably won't respond to some mindless post. But others may, and so I too am surprised at the lack of activity here. But there will be other threads ...

22 posted on 12/09/2003 10:34:09 AM PST by PatrickHenry (Felix, qui potuit rerum cognoscere causas.)
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To: Alamo-Girl
You and I are on the same page here. See #13.

;^)
23 posted on 12/09/2003 10:37:55 AM PST by js1138
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To: general_re
Thank you for your reply! Indeed, some religions have built-in problems...
24 posted on 12/09/2003 10:41:43 AM PST by Alamo-Girl
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To: js1138
Indeed. Thanks for pointing that out!
25 posted on 12/09/2003 10:43:23 AM PST by Alamo-Girl
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To: Alamo-Girl
Indeed, some religions have built-in problems...

You're too kind - my take is that certain worldviews are just plainly dysfunctional ;)

26 posted on 12/09/2003 10:45:42 AM PST by general_re (Knife goes in, guts come out! That's what Osaka Food Concern is all about!)
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To: general_re
So true. So very true...
27 posted on 12/09/2003 10:52:09 AM PST by Alamo-Girl
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To: stanz
it seems that the word "creation" hasn't been mentioned

This from post #14 is close
animal organs weren't designed to support the human respiratory systems.

28 posted on 12/09/2003 10:58:02 AM PST by ASA Vet ("Those who know don't talk, those who talk don't know.")
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