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AnonTechie writes:

Donated human organs are in such short supply that thousands of people die waiting for one every year. U.S. researchers have been shattering records in xenotransplantation, or between-species organ transplants.

The researchers say they have kept a pig heart alive in a baboon for 945 days and also reported the longest-ever kidney swap between these species, lasting 136 days. The experiments used organs from pigs "humanized" with the addition of as many as five human genes, a strategy designed to stop organ rejection.

The GM pigs are being produced in Blacksburg, Virginia, by Revivicor, a division of the biotechnology company United Therapeutics. That company's founder and co-CEO, Martine Rothblatt, is a noted futurist who four years ago began spending millions to supply researchers with pig organs and has quickly become the largest commercial backer of xenotransplantation research.

Rothblatt says her goal is to create "an unlimited supply of transplantable organs" and to carry out the first successful pig-to-human lung transplant within a few years. One of her daughters has a usually fatal lung condition called pulmonary arterial hypertension. In addition to GM pigs, her company is carrying out research on tissue-engineered lungs and cryopreservation of organs. "We're turning xenotransplantation from what looked like a kind of Apollo-level problem into just an engineering task," she says.

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AndyTheAbsurd writes:

(Andy's note: pretty sure it's only "radical" if you discount ideas from science fiction - Technovelgy points out it's been as an idea from at least 2002, and I'm pretty sure earlier examples could be found if one went looking.)

[Wikipedia helpfully has articles on Chimera (mythology) (the source of the name) and Chimera (genetics) (the topic of this research). -Ed.]

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An Anonymous Coward writes:

https://www.sciencemag.org/news/2016/04/researchers-keep-pig-hearts-alive-baboons-more-2-years

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takyon writes:

The National Institutes of Health (NIH) is planning to lift its moratorium on chimeric embryo research:

The National Institutes of Health is proposing a new policy to permit scientists to get federal money to make embryos, known as chimeras, under certain carefully monitored conditions. The NIH imposed a moratorium on funding these experiments in September because they could raise ethical concerns.

[...] [Scientists] hope to use the embryos to create animal models of human diseases, which could lead to new ways to prevent and treat illnesses. Researchers also hope to produce sheep, pigs and cows with human hearts, kidneys, livers, pancreases and possibly other organs that could be used for transplants.

To address the ethical concerns, the NIH's new policy imposes several restrictions. The policy prohibits the introduction of any human cells into embryos of nonhuman primates, such as monkeys and chimps, at their early stages of development. Previously, the NIH wouldn't allow such experiments that involved human stem cells but it didn't address the use of other types of human cells that scientists have created. In addition, the old rules didn't bar adding the cells very early in embryonic development. The extra protections are being added because these animals are so closely related to humans. But the policy would lift the moratorium on funding experiments involving other species. Because of the ethical concerns, though, at least some of the experiments would go through an extra layer of review by a new, special committee of government officials.

You can submit a response to the proposal here up until the end of the day on September 4.

Related: NIH Won't Fund Human Germline Modification
U.S. Congress Moves to Block Human Embryo Editing
China's Bold Push into Genetically Customized Animals
Human-Animal Chimeras are Gestating on U.S. Research Farms

Original Submission

mrpg writes:

Embryos that are less than 0.001% human - and the rest pig - have been made and analysed by scientists.

It is the first proof chimeras - named after the mythical lion-goat-serpent monster - can be made by combining material from humans and animals.

However, the scientific report in the journal Cell [open, DOI: 10.1016/j.cell.2016.12.036] [DX] shows the process is challenging and the aim of growing human organs in animals is distant.

It was described as an "exciting publication" by other researchers.

To create a chimera, human stem cells - the type that can develop into any tissue - are injected into a pig embryo.

The embryo - now a mix of human and pig - is then implanted into a sow for up to one month.

The process appears very inefficient - of the 2,075 embryos implanted only 186 continued to develop up to the 28-day stage.

Human-pig 'chimera embryos' detailed

Original Submission

anubi writes:

A few days ago, SN ran a story on human-pig chimeras.

Here's another story about mouse-rat chimeras providing insight on a problem that's plaguing many of us... diabetes and other pancreas-related issues.

From the story:

Growing human organs in other animals is a small step closer to reality.

While human-animal chimera work is still in its infancy (and faces ethical and funding hurdles, see sidebar), hybrids of rats and mice are already hinting that growing an organ from one species in another is a viable strategy for curing some diseases. Researchers report January 25 in Nature that they grew mouse pancreases in rats. Mouse insulin-producing cells were extracted from the rat-grown organs and transplanted into diabetic mice, curing their diabetes. Transplanted cells kept the mice's blood sugar normal for more than a year even though the mice were not given immune-suppressing drugs to prevent rejection after the first five days following the transplant. That finding raises the hope that animal-grown organs tailored to individual patients could be transplanted without fear of rejection.

Hopefully, these guys succeed!

Original Submission

takyon writes:

eGenesis Bio, a startup co-founded by George Church and Luhan Yang, has used CRISPR/Cas9 to inactivate Porcine Endogenous Retrovirus (PERV) in piglets. It is one step towards the creation of pig organs that could be transplanted into humans:

"This is the first publication to report on PERV-free pig production," Yang, who is chief scientific officer at Egenesis, said in a news release. [...] There are two huge hurdles to getting animal-organ transplants to successfully work in humans — a process known as xenotransplantation. The first, Yang told Business Insider in March, is the virology, or the fact that pigs carry genes encoded with viruses that could transmit disease to humans — that's the PERV genes that Egenesis is working to deactivate.

The second hurdle, she said, is the immunology. Since the pig organ would be foreign to the body, the person's immune system might try to kick it out, rejecting the organ. Those proved too challenging for a slew of researchers going after this subject in the 1990s [open, DOI: 10.4103/0970-1591.33729] [DX]. Ideally, CRISPR will help tackle those issues "that were insurmountable before," Yang said. "We think the advancement of gene editing can help us address both of them," Yang said.

Also at MIT and The New York Times (picture of cute piglets ready for harvest).

Inactivation of porcine endogenous retrovirus in pigs using CRISPR-Cas9 (DOI: 10.1126/science.aan4187) (DX)

Original Submission