In fact, pigs are studied for their biocompatibility with the human. So far, the animals have lived more than a year with no problems, Tector said. Pig heart valves are already being routinely transplanted into humans, some diabetes patients have transplanted pig pancreas cells and pig skin is often used for treating patients with severe burns. But there are also plenty of barriers to the cross-species sharing. "There is so much desperation among people on transplant lists, and 20 a day are dying as they wait", said Dr. Adam Griesemer, a xenotransplantation researcher and transplant surgeon at Columbia University Medical Center. And it could eventually become a tool that lets pigs serve as organ donors for humans following a milestone advance reported by genomics-centered biotech eGenesis. This involves immunological changes as well as making the tissues compatible and fixing blood-clotting issues. The Alabama group, though, does not think pig retroviruses are a major concern.
The private company eGenesis was founded by two men, is thus achieved to obtain the birth to 37 piglets whose organs may be suitable for xenotransplantation, is a transplant from donor animals. They showed that these viruses had integrated into the human DNA and could be transmitted to other human cells. In a lab dish the pig viruses infected human cells, and those infected cells were able to infect other human cells that had not been directly exposed to pig cells.
The researchers first demonstrated that porcine retroviruses are transferred to human cells.
They used a line of pig cells from connective tissue that contained 25 PERVs. They speculated that the genetic slicing and dicing was enough to signal to the cells that something was drastically wrong and that they should commit suicide-a cell process called apoptosis. To enable survival of the cells, the team had to treat them with a chemical cocktail of pro-survival factors. The result was 100 percent PERV eradication.
Now they have taken the genetic material from such cells and, using a similar technique to the one used to clone Dolly the sheep, inserted it into pig eggs. The latest landmark development in the field comes from a team of scientists who successfully created genetically modified piglets free of 25 retroviruses that are generally present in pigs but thought to cause harm to humans.
There's still a lot of work ahead to turn the swine into human organ factories.
Speaking to the New York Times, Dr. David Klassen, chief medical officer at the United Network for Organ Sharing, a nonprofit organization that manages the U.S. transplant system, said the study "could be a real game changer".