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CRISPR/Cas9 Gene Editing in Pigs to Solve Organ Shortage?

pigs as organ replacement sources

1 - 5 of 5 posts

robert99 robert99 Sweden Posts: 1360
1 5 Jan 2016
... scientists have looked to other animals as potential organ donors, but every small milestone has been blemished by larger setbacks related to organ rejection. But transplantation medicine has been revived again by a new era of gene-editing techniques called CRISPR/Cas9. Will this technology enable scientists to overcome the barriers of cross-species transplantation and fill the need for organs?

Pigs are, surprisingly enough, considered the next best candidate for providing organs for human transplants. The organs of the pig are exposed to a similar immune system as humans, and also shares similar functions and a close size match to ours. Already pigs have been of great service to medicine, as doctors have been replacing damaged human heart valves with pig valves for the past 50 years.

But moving from organ part to whole organ has been especially challenging. So far, lab trials of transplanted pig organs into baboons have been discouraging, with successes measured in days. Failure of the transplant to sustain in another animal is largely due to the host’s tendency to recognize and attack foreign organs. In addition to immunosuppressant drugs, scientists have found a few ways to block a pig antigen called α-1,3-galactose that seems to trigger most of the immune responses. They’ve created a pig that’s entirely missing the α-gal, removing the antigen completely. But despite these advances, the immune system has turned out to be much more complex than they anticipated. The current record for a pig-to-baboon kidney xenotransplantation is 136 days.
Enter the CRISPR/Cas9, a gene editing technology that’s taken the science community by storm. The system is heralded as a game-changer for many areas of science, but it may be the biggest game-changer for transplantation medicine. Because of its efficiency and specificity at editing genes, researchers can now quickly and accurately silence genes in the pig that could cause rejection or infection in the human.

CRISPR/Cas9 can do this and much more: it has allowed scientists to target multiple genes all at once. In other words, systematic silencing of all the antigen genes in the pigs would take decades, whereas CRISPR/Cas9 would reduce this time to mere months. Already a life-sciences company eGenesis, announced that it had edited the pig genome in 62 places in one go with one molecule. The 62 genes corresponded to viral genes in the pigs, PERVs, which once edited, could no longer trigger viral infections. eGenesis is coincidentally headed by George Church, one of the seminal experimentalists who optimized the CRISPR/Cas9 technology.

“This work brings us closer to a realization of a limitless supply of safe, dependable pig organs for transplant,” Dr. David Dunn, transplantation expert at the State University of New York at Oswego.

robert99 robert99 Sweden Posts: 1360
2 5 Jan 2016
Prof Brun Ulfhake has said that gene modified pigs could be used for medical research, as early as within a year. Heart and lungs would be more human-like to allow medical testing. How this would effect the pigs, well ....
see in Swedish though.

reddapanda reddapanda ACT Posts: 381
3 5 Jan 2016
Wow. Thanks for this information/topic Robert. Side-track but it made me think of the movie "never let me go", which is sort of about preparing cloned humans to become adults and then transplant donors. I guess if more people put themselves on voluntary organ donation lists there'd be less call for pigs to give theirs. Although, as the clip says for the past 15 years humans have been receiving heart valves from pigs.

robert99 robert99 Sweden Posts: 1360
4 5 Jan 2016
.. and the movie "The Island" which is about a clone as your own personal organ-bank.

So vegans, will you accept pig-organs?

reddapanda reddapanda ACT Posts: 381
5 5 Jan 2016
Hello Robert,

I think your question is something many people reading may not have a ready-answer for? Meaning that we're not in a life-death scenario of awaiting a transplant. Instead, perhaps we should become greater organ donor advocates? That'd be working beyond the individual hypothetical level, to the better societal option level?

Hmmm I think too, perhaps I have a bit of a utilitarian (Peter Singer inspired) view about... the relative merits of eating bacon compared saving a people's lives (and that should sort of direct our efforts too). Personally I don't really want to join the "tiny vegan club" of abstaining from everything, maybe just the main things.

I think getting into 'health' arguments is a bit of a strategic risk of sorts (for advocates). Anyway, enough from me. Have a good evening.