Scientists de-bug pig genome in preparation for farming organ donors – Ars Technica

After a thorough antivirus scan, de-bugged pigs are a step closer to growing organs for us.

Researchers used the latest gene editing technology to deactivate 25 remnants of ancient viruses, called porcine endogenous retroviruses (PERVs), that had embedded in the DNA of a pig cell line. Pig genomes are rife with lurking PERVs, which threaten to emerge and infect humans. But with a genome wiped of active viruses, the researchers produced 37 piglets that are PERV-free. Thecreation of those clean little porkers, reported Thursday in Science, is progress toward using pigs as human organ donors, the researchers say.

Our study highlighted the value of PERV inactivation to prevent cross-species viral transmission and demonstrated the successful production of PERV-inactivated animals to address the safety concern in clinical xenotransplantation, the authors concluded.

Researchers have always worried about PERVs in pig-to-human transfers. The retroviruses, which are passed on through hog generations, have never proven to transmit to humansno human PERV disease cases have ever been reported, even in patients who have received pig tissue transplants. Still, the concern lingers. And in labs, PERVs can jump from pig cells to human cells.

Researchers saw this first hand in the new study, led by Harvard geneticist George Church and Luhan Yang, a bioengineer and president of eGenesis, a biotech start-up she and Church co-founded. Before sweeping away PERVs from a pig cell line, they showed that PERVs from a line of pig cells infected a line of human cells when researchers grew them together. And that infected line of human cells infected another line of human cells when researchers grew them together.

Theres still a lot of work ahead to turn the swine into human organ factories. And its unclear if researchers will end up needing PERV-free piglets for the feat. But for now, Church, Yang, and their team think their new pigs may serve as a foundation pig strain, which can be further engineered to provide safe and effective organ and tissue resources for xenotransplantation.

Science, 2017. DOI: 10.1126/science.aan4187 (About DOIs).

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Scientists de-bug pig genome in preparation for farming organ donors - Ars Technica