‘Mini-pig’ a promising sign for transplants

A team of Korean scientists has successfully produced a genetically engineered and cloned piglet that is partially deprived of the genes that cause the human body to reject pig organ transplants, the Science Ministry said yesterday.

The world’s second birth of a so-called “mini-pig” is expected to pave the way for more successful pig-to-human transplants.

According to Korea Biotech R&D, a state-run research group composed of scientists from different universities nationwide, the piglet was born healthy on April 3 and is now being cared for at the National Institute of Animal Science in Suwon, on the outskirts of Seoul.

When pig organs are transplanted into humans, a type of immune reaction called hyperacute graft rejection occurs within minutes to hours, rendering the organ non-functional.

By removing one of two genes involved in the hostile immune response, the Korean scientists overcame a major obstacle in transplants between pigs and humans. A research team at the University of Missouri-Columbia, led by Randall Prather, initially succeeded in doing the same in 2002. Four such piglets were born at the time.

When human organs deteriorate to a certain stage, transplantation from other humans is the only real solution available now.

But huge demand and little supply has prompted scientists to come up with an alternative source - organs from animals. According to the Science Ministry, an average of around 6,000 people in the United States have died due to human organ shortage in recent years. The ministry estimates that there will be 1.58 million people on the waiting list for organ transplantation by 2015.

“Commercialization of mini-pig organ transplantation into humans may be possible around 2017,” said Lim Kyo-bin, a team member and professor at the University of Suwon.

The ministry said Korea Biotech R&D will conduct a joint study with the Welfare Ministry on commercializing pancreas islet cells, heart valves and hearts from mini-pigs for transplantation. With the National Institute of Animal Science, the research center will work on mass production of cloned piglets without the immune rejection genes.

Pigs are species deemed to be more acceptable donors for humans. The type of pigs used in the study comes from a unique line of miniature swine.

By Seo Ji-eun [spring@joongang.co.kr]