The monkey survived for two years after a pig transplant
Cynomolgus macaques survive in the same environment as the monkeys with kidneys. In the United States alone, nearly 88,000 people are waiting for a kidney donation
More than 20 cynomolgus macaques were given the same immunosuppressive drug cocktail as the pigs and pig kidney was transplant into them. All of the monkeys that receivedKidney without the seven human genes survived for just 50 days. By comparison, 9 of the 15 monkeys that received kidneys with the human genes did. The five monkeys who lived for more than one year were all males. The test shows that the transplanted organs performed as well as the native ones.
Kidneys remove waste, produce urine, and balance fluids in the body. In the United States alone, nearly 88,000 people are waiting for a kidney donation, according to data from the federal Organ Procurement and Transplantation Network. About 31,000 received one in the year 2022, a drop from the previous year.
Are pig xenotransplant recipients and their organs safe and healthy? A study of gene modification in live pigs by eGenesis
69 genes were edited, which was the most extensive editing done in live pigs. Several edits target the rejection-related molecule, and others target the retrovirus genomes that became in the pig genome long ago. The risk of human xenotransplant recipients and their organs getting infections in their transplants is not known despite previous research showing that embedded genomes produce viral particles in a laboratory setting.
This is a “proof of principle in non-human primates to say our [genetically engineered] organ is safe and supports life”, says Wenning Qin, a molecular biologist at the biotech firm eGenesis in Cambridge, Massachusetts, who co-authored the study published in Nature1 on 11 October.
In the past few years, researchers have transplanted pig hearts into two living people2, and demonstrated that pig hearts3 and kidneys4 can function in people who have been declared legally dead.
Such research is crucial, given the dearth of suitable organ donors, says David Cooper, a xenotransplant immunologist at Massachusetts General Hospital in Boston, who was not involved with the study but is a consultant for eGenesis. In the United States alone, more than 100,000 people are awaiting an organ transplant, and about 17 of them die each day.
Human genes are added to keep the transplant organ healthy. Two genes prevent unnecessary blood clotting.
Although survival times can be up to two years, they were more varied than the team had expected. But researchers engineered the pig genomes with people in mind, not non-human primates, so it’s likely that they would fare better in humans, Mohiuddin says.
Not all researchers are convinced that such extensive genetic changes are necessary. Megan Sykes, a transplant immunologist at Columbia University Medical Center in New York City, applauds the researchers for studying the effect of so many genes.
But the survival is not “strikingly better than what has been seen before with many fewer gene modifications”, she says. With each extra gene modification, they become harder to produce, which might make it more difficult to scale up, she says.
In principle, Mohiuddin agrees that some of these edits might be “overkill”, but he is optimistic that one day there will be genetically modified pigs that eliminate the need for immunosuppressive drugs.
Locke says he does not know how simple or complicated these gene edits can be. Clinical trials will be very important there.
A study of gene modification in live pigs by eGenesis 69 genes has shown that pig hearts and kidneys can function in people who’ve been declared legally dead. The team transplanted pig hearts into two living people, and demonstrated that pig hearts and kidneys can function in people who have been declared legally dead. The study was published in Nature.