Lord Winston to farm pigs for transplants

Sarah-Kate Templeton

The Sunday Times - UK

September 7, 2008

Lord Winston, the fertility expert and Labour peer, is to begin breeding genetically modified pigs in the next three months to produce hearts, livers and kidneys for transplanting to humans.

Winston has pioneered a simplified technique to create pigs with “humanised” organs that will not be rejected by the patients’ immune systems.

He expects the technique to provide a solution to the shortage of donor organs within 10 years. Attempts to transplant animal organs – xenotrans-plantation – were abandoned because the tissue was rejected and because of fears that animal viruses would spread to humans. Enthusiasm for the procedure waned in the late 1990s after patient deaths.

Winston and his colleague, Dr Carol Readhead of the California Institute of Technology, believe pigs can be genetically modified to exclude the dangerous viruses.

The pigs will be bred with about six human genes to prevent patients rejecting their organs. Winston’s team will need to prove that the pig organs can be sufficiently modified to survive long-term in the human body.

He says his method could see hundreds of genetically modified pigs reared simultaneously for their organs. Organs could be taken from pigs as young as one year.

He says xeno-transplantation is the best hope to tackle the shortage of organs. A record number of almost 8,000 British patients are waiting for an organ.

The government is considering imposing presumed consent, whereby organs would be taken from the dead unless they had specifically expressed a wish not to give them away, though experts say this will not solve the problem.

In an article for The Sunday Times, Winston said other options also had shortcomings: “Artificial, human-made devices, like mechanical hearts, never work as well as biologically produced organs. And although huge publicity has recently been given to the idea of growing organs, culturing hearts and livers possibly from stem cells, this technology is still very primitive and is unlikely to come to fruition in the next 20 to 30 years.

“Pigs organs are the right size for human transplantation and they work similarly to human organs.”

Winston’s method of creating genetically modified animals involves either injecting human genes, carried by a virus, into the testicles of the piglets or adding them directly to the sperm. He argues the technique is more feasible and humane than rival methods, which involve cloning pigs and adding the genes to the cloned embryos before they are transferred into the sow’s womb.

Winston has filed several patents covering the technique and claims it “carries huge commercial opportunities”.

He is moving the research project from Britain to America after British regulations and a shortage of funding prevented experiments here. The pigs will be bred in Missouri.

In his article Winston added: “It has been difficult to pursue the research in the UK . . . Having got pigs producing transgenic sperm, we were suddenly informed we could not mate them because of some Defra [Department for Environment, Food and Rural Affairs] and EU regulations. We are not even permitted to do postmortems on the pigs so we cannot prove we have been successful.”

Defra said the breeding of genetically modified animals for research was permitted by the Home Office if a licence was granted. A spokesman said, however, that scientists must meet the criteria for a licence to be granted.

Xenotransplantation has been fiercely opposed by ethicists. In a report for the Department of Health in 2003, Professor Sheila McLean, director of the Institute of Law and Ethics in Medicine at Glasgow University, warned the government that potentially lethal viruses could be passed from pigs to humans.

timesonline.co.uk