Through a Novel Gene Editing Technology, Pig-to-Human Organ Transplants May Save Lives
As of July 2017, 117,000 Americans—men, women and children—are on the national transplant list waiting to receive a vital organ such as a kidney, liver, heart or lung to save their lives. Unfortunately, the list of needy patients keeps growing while donors are decreasing causing an alarming organ shortage. As a consequence, 22 people will die each day.
Dr. George Church, whose lab at Harvard spun off eGenesis, a company focusing on genetically altering pig organs to make them safe for transplant in humans, led the experiments that may make organ transplants more viable than ever. He believes the first pig-to-human transplants could occur within two years.
It’s been a long time coming. Despite the success of porcine heart valve replacements, experiments with pig organ transplants fell out of favor in the 1990s when scientists discovered that retroviruses within pig hearts could unleash immune storms ravaging the human body after transplantation. Now thanks to CRISPR, a gene editing technology that can modify DNA inside living cells, scientists can eliminate viruses that lay dormant in the pig’s genome—which is exactly what Dr. Church and his team managed to do.
They modified pig cells by creating a “humanized” immune system; they then modified other cells to eliminate risky viruses. Both sets of genetic changes were merged into a single pig cell to be turned into a pig which could be used to clone an entire animal. The cell was subsequently injected into an egg to form an embryo and then transferred to a surrogate sow—15 piglets survived.
eGenesis may become the pioneer in learning just how far gene editing can go before these modified pigs start to develop their own health problems. What’s more, these problems once detected, may be edited out of the cell in the laboratory.
The days of our national waiting list may thankfully be numbered. It’s now up to regulators and scientists to reach consensus about CRISPR and its potential.