New organs from 'designer pigs' could be ready to use in humans within a decade. The hope is to transplant the organs into humans who require them to help solve the problem of the shortage of transplant organs.
Lord Robert Winston, the fertility expert from Imperial College London, is one of the directors of Atazoa, the spin-out company that is pioneering the work on the pigs with a team at the California Institute of Technology, Pasadena, led by Dr Carol Readhead. He is attempting to genetically modify and breed special kinds of 'mini-pigs', which are about a quarter of the size of normal farm pigs and whose organs are the right size for humans.
The male pigs are injected with a cocktail of genes that alter their sperm, and genes are taken up in the offspring after they mate with normal sows. If the correct genes are taken up, the porcine organs will be modified to have human proteins on them, in an attempt to prevent rejection by the human body due to the immune system recognising and rejecting 'foreign bodies' on the pig organ. The hope is that once the donor pig has been created, a limitless and cheap supply of organs will be produced. Lord Winston has already successfully incorporated a test gene into the sperm of six pigs.
There are currently 8000 people on the waiting list for transplants in the UK, 7000 of who are waiting for a kidney. There are only enough donors for 3000 transplants per year. Lord Winston says: 'there is a massive shortage. Essentially, if you are waiting for a transplant, you are waiting for someone to die in a car accident'.
Pigs are considered ideal for 'xenotransplantation' (animal-to-human transplants) due to the similarities in their physiological make-up to humans, and they have many of the same diseases. Patients who receive the pig organs, however, will still have to take powerful immunosuppressant drugs for the rest of their lives, although no more than patients who receive human organs. Other benefits of the breeding of these pigs include biomedical research into understanding human diseases, and testing new medicines in the pigs to avoid risks to humans in late phase clinical trials.
Lord Winston aims to breed the first pigs next year, and hopes that transplantable organs could be ready within two to three years for testing and licensing. He says there have been problems with the progress of the project, however, due to 'red tape' that bans his team from mating and producing offspring from the transgenic pigs. The research might have to be moved to the US, where the regulations are more relaxed.
There has been some opposition to the research, for example from the campaign group People for the Ethical Treatment of Animals. It maintains that the 'obstacles to success in this research are colossal, the risk to humans incalculable and the cost in animal suffering is enormous'.