Scientists transplant, grow human stem cells in pigs

Researchers have developed a new line of genetically modified pigs that do not reject transplants, an advance that allows for future research on stem cell therapies.
One of the biggest challenges for medical researchers studying the effectiveness of stem cell therapies is that transplants or grafts of cells are often rejected by the hosts.
This rejection can render experiments useless, making research into potentially life-saving treatments a long and difficult process.
Now, researchers at the University of Missouri have shown that a new line of genetically modified pigs will host transplanted cells without the risk of rejection.
"The rejection of transplants and grafts by host bodies is a huge hurdle for medical researchers," said R Michael Roberts, Curators Professor of Animal Science and Biochemistry and a researcher in the Bond Life Sciences Center.

"By establishing that these pigs will support transplants without the fear of rejection, we can move stem cell therapy research forward at a quicker pace," Roberts said.

Researchers implanted human pluripotent stem cells in a special line of pigs developed by Randall Prather, an MU Curators Professor of reproductive physiology.
Prather specifically created the pigs with immune systems that allow the pigs to accept all transplants or grafts without rejection.
Once the scientists implanted the cells, the pigs did not reject the stem cells and the cells thrived.
Prather said achieving this success with pigs is notable because pigs are much closer to humans than many other test animals.

"Many medical researchers prefer conducting studies with pigs because they are more anatomically similar to humans than other animals, such as mice and rats," Prather said.
"Now that we know that human stem cells can thrive in these pigs, a door has been opened for new and exciting research by scientists around the world," Roberts added.
"Hopefully this means that we are one step closer to therapies and treatments for a number of debilitating human diseases," Roberts said.
The study was published in the Proceedings of the National Academy of Sciences.