'Knockout pigs' bring animal to human transplants closer
'Knockout pigs', which could in the future be used for animal to human transplants, have been produced by PPL, the US commercial offshoot of the Scottish Roslin Institute. The five piglets, born on 25 December have had the specific gene that leads to the human immune system rejecting pig organs inactivated. The piglets were born as a result of using nuclear transfer and PPL's gene targeting technology. PPL's head of research, Alan Colman, said that it may be necessary to add certain genes before such pigs are ready for trials, but that human trials are likely to be only four or five years away. If successful, it will be possible to transplant cells from pigs into failing organs to deal with diseases such as diabetes, Parkinson's and Alzheimer's. 'With one of the major technical hurdles and scientific risks overcome, the promise of xenotransplantation [transplantation from animals to humans] is now a reality, with the potential to revolutionise the transplant industry,' said Mr Colman. 'This advance provides a near term solution for overcoming the shortage of human organs for transplants as well as insulin-producing cells to cure diabetes,' added Dr David Ayares, chief operational officer and vice president of research at PPL's US division. The piglets, named Noel, Angel, Star, Joy and Mary have had the alpha 1.3 galactosyl transferase gene 'knocked out', which is responsible for making an enzyme that adds a sugar to the surface of pig cells. This is recognised by the human immune system as foreign and is rejected, often in a matter of minutes. There are however still hurdles to overcome. These include the theoretical risk that pig viruses may be transferred to humans, causing new diseases, as well as opposition on ethical grounds. Dr Donald Bruce from the Church of Scotland has welcomed the prospect of using pig organs to save human lives if a number of conditions are fulfilled, 'but it raises serious ethical issues over the use of animals and a major question of safety,' he is reported has having said. PPL is now looking for a partner to invest the funds necessary to bring the technology to a market that it believes is worth around 12.8 billion euro a year. 'PPL has devoted a lot of resources to this over four or five years and now it's time for the funds to come from somewhere else, either a venture capitalist or a pharmaceutical company,' Dr Martyn Breeze, product development director with PPL, is reported as having said.