US scientists closer to pig-to-human organ transplants

By Barry Eitel

SAN FRANCISCO

Scientists announced Thursday they have discovered a gene editing method that could clear the way for growing human organs in pigs meant for transplants.

The theory of growing human organs inside pigs has been around for some time but has been hampered because pigs carry genetic diseases that can be harmful to humans.

Specifically, porcine endogenous retroviruses (PERVs) can be carried in the genes of pigs even if they are not ill. Research has shown PERVs can cause leukemia or other cancers in humans.

But a breakthrough using CRISPR gene editing technology paves the way for pigs free of PERVs. Scientists at Harvard University, as well as teams of researchers in China and Denmark, discovered they could pinpoint the genes linked to PERVs and remove them. Theoretically, the genetically modified pigs could be used to harbor organs meant for human patients, a process called xenotransplantation.

The study was partly funded and conducted by the biotech company eGenesis. The landmark report was published in the journal Science.

“This is the first publication to report on PERV-free pig production,” eGenesis co-founder Luhan Yang said in a statement.

“This research represents an important advance in addressing safety concerns about cross-species viral transmission. Our team will further engineer the PERV-free pig strain to deliver safe and effective xenotransplantation.”

There is a drastic shortage of organs available for transplants around the world. The U.S. Department of Health and Human Services estimates 117,000 men, women and children are currently awaiting organ transplants in the U.S. alone. An average of 22 Americans die each day waiting for an organ.

Xenotransplantation using pigs has been singled out as a possible solution to the organ crisis because the organs of pigs and humans are similar in size and function.