Professor Yun Ik-jin of Konkuk University Medical Center's (KUMC) department of surgery will get 1.29 billion won ($1.2 million) in funding from the Rural Development Administration to develop a method of xenotransplantation using pig organs.

Xenotransplantation, also called cross-species transplantation, refers to grafting or transplanting organs or tissues between different animal species.

The research will aim to extend the survival rate of the monkeys getting xenotransplantation using pigs’ organs and ultimately apply the findings to cross-species transplantations involving humans. It also seeks to uncover why animals die following xenotransplantation considering most do so within two months of operation.

The study, which began last month, will last until December 2020 to span a total of 34 months.

One of the difficulties of cross-species transplantation originates from an immune response called a hyperacute rejection (HAR) thought to be caused by the alpha 13-galactosyltransferase gene, called the alpha gal. Alpha gal is present in all animals including primates.

Professor Yun’s team, which has completed 10 interspecies kidney transplants, 22 heart transplants, and five corneal transplants since 2011, have used a transgenic cloned pig without the alpha gal gene (called alpha gal gene-knockout or GalT-KO) to minimize the immune reaction.

The team, in previous xenotransplantations, found a monkey that received an organ from a GalT-KO pig went two hours without a hyperacute rejection. Usually, when a pig's kidney is transplanted to a monkey, a hyperacute rejection occurs within 30 minutes.

The professor’s team has since transplanted the heart of a GalT-KO pig into a monkey to find the monkey survived 60 days following the transplant, maintaining a relatively smooth heart rate. The team also transplanted a kidney from a GalT-KO pig into a monkey, and the monkey survived 32 days. Both are the longest survival records in Korea.

"The primate model is a necessary step to the clinical application of xenotransplantation by examining the immunoreactivity that can occur in humans and by examining its efficacy," Professor Yun said. "It is significant that the monkeys that received heart and kidney transplants survived as long as they did, marking the longest records in the country."

The research results were published in the international journal “Transplant proceeding.”