GENETICALLY MODIFIED PIGS FOR HUMAN TRANSPLANTS

Genetically Modified Pigs For Human Transplants
Korean scientists have created genetically modified pigs whose organs could be transplanted into human patients. The pig, named Xeno, was born in April 2009 at the National Institution of Animal Science in Suwon in Gyeonggi Province (South Korea). The pig belongs to a kind of mini-pig "which weighs only 80 kg.

Scientists worldwide are working on the use of animal organs to meet the shortage of organs for human transplants, one of the major problems of medicine. Many teams of researchers and try to mass produce these hybrid pigs able to produce parts of bodies "humanized" (Langerhans cells of the pancreas, heart valves, hearts, etc...). But it remains to prove that these organs can be transplanted into human patients without any risk.

The pig is potentially a good candidate to serve as an organ donor, but the main challenge for transplant organs from human patients of just one sugar molecule on the surface of cells that causes an immune reaction by the immune system of man. The molecule called alpha galactose 1.3 "or" alpha gal "present on all non-primate animal cells is recognized by the human immune system in spite of immunosuppressive treatment to prevent graft rejection. Animal organ transplant survives usually only a few hours. Korean researchers have produced a pig "GAL-knockout", which do not produce alpha-gal and would be invisible to the immune system. The technique is not new since it has already been used in the past by researchers at Harvard University (USA). Korean researchers think they have better technology.

Korean researchers have proceeded in the following manner, they were first removed one of two genes encoding the alpha-gal (the a1, 3-galactosyltransferase) from a somatic cell of a mini-pig and then inserted cell into an egg whose nucleus has been removed to create a clone. This required extensive testing, among the hundreds of tests, four embryos have been cloned successfully and one male named Xeno has survived.

The piglet product could be used to create a new breed of genetically modified pigs lacking Gal alpha, which increase the chances of producing compatible immune organs called "humanized", scientists suggest.

Researchers hope to begin clinical trials in humans in 2012 before commercial use these mini-pigs genetically altered to 2017.

Sources: BE Korea number 47, AFP and KoreaTimes