Researchers hope sheep-human hybrids could be used for organ transplants

CTV News Channel: Human-sheep hybrid Reproductive biologist and co-researcher Pablo Ross explains how human-sheep hybrids could grow human organs to combat type 1 diabetes.

Researchers in California are aiming to cut down on long wait times for organ transplants by using human stem cells to grow a patient a new organ inside pigs and sheep.

The research team says the science works by inserting the patient’s stem cells inside an embryo of an animal during the earliest stages of reproduction. When the animal becomes fully grown, presumably it will have fully grown human organs.

“The idea here is that we would like to grow this organ from the patient’s own cells,” Dr. Pablo Ross, an associate professor at the University of California and co-author of the research, told CTV News Channel.

“Growing an organ in a lab has proven to be a very difficult task but animals grow their organs every time and they always do it right.”

Ross and his team presented their findings on Sunday during a talk at an annual meeting for the American Association for the Advancement of Science in Austin, Texas.

The team says this work, if successful, would greatly reduce the wait times for organ transplants and should improve the success rate of the transplant as the organ would be made from the cells of the person who needs it.

Health Canada says there were more than 4,500 people waiting for an organ transplant in 2014 -- 278 of them died.

While it might seem like a far-off idea, scientists have already had success with growing a mouse pancreas inside a rat.

“We can grow a mouse pancreas inside a rat, then take cell from that mouse pancreas and put it back in a diabetic mouse and basically cure diabetes without really requiring immunosuppression,” Ross said.

The team has also been able to use genome editing to produce pig and sheep embryos that are unable to develop a pancreas. The hope is that the human stem cells would grow to replace the missing organ.

Ross and his team just recently made a breakthrough where they were able to introduce human stem cells into pig embryos, the first major hurdle for this research to be successful.

For an animal to start growing human organs, Ross says about one per cent of the animal’s embryo cells have to be human. So far, they can get to about .001 per cent in pigs and .01 in sheep.

There are a number of advantages in using pigs and sheep to grow human organs. Both animals have organs that are already similar in size and shape to humans and also grow from an embryo to a fully grown adult fairly quickly, resulting in shorter wait times for the patient.