Cloned pigs could solve transplant problems

Five newborn cloned piglets could have a dramatic impact on attempts to transplant animal organs into humans, it was announced today.

They are the world’s first cloned pigs produced from cells that have been genetically modified.

The same technique might make it possible to create pigs bred for human transplants whose organs will not be rejected by patients’ immune systems.

A number of scientific teams are working on producing pigs from which kidneys, hearts and other organs can be taken for human transplants.

But one major hurdle is that pigs have a specific gene which causes the human immune system to reject pig organs.

Making cloned copies of ‘‘knock-out’’ pigs in whom this gene has been inactivated would solve the problem.

Today’s announcement was made by Edinburgh-based biotech pioneers PPL Therapeutics which last year introduced the world’s first cloned pigs.

The five new clones each had a foreign ‘‘marker gene’’ inserted into their DNA in order to demonstrate that genetic modification was possible.

Meanwhile, PPL has already moved on towards erasing the organ-rejection gene in pig clones. The gene has been targeted and knocked out in cells which are now in the process of being converted into animals.

Clinical trials of pig-to-human organ transplants could be as little as four or five years away, a PPL statement said today.

Analysts believe the worldwide market for solid organs alone could be worth more than £3bn. As much again may be obtained from cellular therapies, such as transplantable cells that produce insulin for treating diabetes.

PPL’s research director, Alan Colman, said: ‘‘This exciting world first ... is an important step on the road to producing a ‘knock-out’ pig, which would be a significant milestone in validating this approach to hyper-acute rejection.’’