Genetically modified pigs were specially developed to host transplanted cells without rejectionReuters

Researchers have developed a new line of genetically modified pigs that do not reject transplants, a landmark development which has paved the way for future research on stem cell therapies.

One of the biggest challenges for medical researchers studying the effectiveness of stem cell therapies is the rejection of transplants or grafts of cells by the hosts. This rejection can render experiments useless, placing restrictions on potentially life-saving treatments.

Now, researchers at the University of Missouri have shown that a new line of genetically modified animals 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," R. Michael Roberts, researcher in the Bond Life Sciences Center, told Science Daily. "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."

In the study, researchers implanted human pluripotent stem cells in a special line of pigs developed by Randall Prather, a professor of reproductive physiology.

Prather specifically created the pigs with immune systems that allow the animals 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.

According to Prather, 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," he told the Business Standard.

"Physically, pigs are much closer to the size and scale of humans than other animals, and they respond to health threats similarly. This means that research in pigs is more likely to have results similar to those in humans for many different tests and treatments."

"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."

The study is published in the journal Proceedings of the National Academy of Sciences.