Researcher claims organ transplant breakthrough

A US gene researcher says he has cloned a miniature pig in a development he called a major step towards transplanting pig organs into humans.

Randall Prather, a professor at the University of Missouri-Columbia, announced that he had cloned a miniature pig – without the gene that has kept doctors from successfully transplanting pig organs into humans.

Pigs are potential human lifesavers because they are physiologically similar to people and more plentiful than non-human primates, such as baboons.

However, pigs are born with a gene that coats their organs with a sugar molecule, called a-1,3-galactosyltransferase or GGTA1, which triggers organ rejection when transplanted into humans.

Prather told the International Embryo Transfer Society in Auckland, New Zealand, that the cloning process for his female pig, Goldie, born on November 18 in Columbia, Missouri, blocked both copies of the gene.

“We have only one (pig) living which has both gene copies modified so they’re non-functional,” Prather, a professor of reproductive biotechnology, told The Associated Press news agency.

He said checks of the pig’s cells confirmed that both copies of the gene producing GGTA1 “have been knocked out”.

Prather said the work still had to be reviewed by independent scientists and was writing up the results for publication in a science journal.

But he called Goldie’s birth “the first step through the brick wall” separating scientists and doctors from transplanting pig organs into humans, known as xenotransplantation.

Dr David Cooper, professor of surgery at Harvard Medical School and a former president of the International Xenotransplantation Association, called the development “a very important step forward”.

Goldie’s birth means “we’re well on the way to considering a clinical trial of xenotransplantation of pig organs into humans” within three years or so, he said today, from Massachusetts.

Overcoming the body’s massive immune response after it perceives a foreign organ is one of the greatest hurdles to animal-to-human organ transplants.

Without the sugar, the antibodies can’t attach, and therefore the rejection process cannot begin, Prather says.

He anticipated other rejection problems to emerge as the work developed.