A research team from the Department of Biomedical Sciences at CHA University has created induced pluripotent stem cells (iPSC) that can be transplanted without immune rejection reactions in nearly half of Koreans.

CHA University Medical School Professor Song Ji-hwan

The study, led by CHA University Medical School Professor Song Ji-hwan, was published in the online version of the international journal Stem Cell.

Researchers first selected 10 types of cord blood that has a high human leukocyte antigen (HLA) haplotype in Koreans through a haplotype screening process and started creating the iPSC. HLA is an antigen that differentiates the tissues of one person from another. Severe immune rejection reactions occur when transplanting organs or cells between different HLA types.

The type of HLA is determined by the haplotype, which is a set of alleles in each locus on a chromosome. Since the HLA type is determined by one haplotype from the father and one haplotype from the mother, the probability of HLA type matching with a sibling is about one-fourth. In the case of non-blood donors, however, the chance falls to less than 1 out of 10,000.

The 10 types of cell lines created by Song’s team do not give rise to immune rejection reactions in a majority of patients if the HLA haplotype matches, CHA said.

The iPSC made from patient’s somatic cells have a low probability of creating an immune rejection. However, culturing and transplanting iPSC from somatic cells from a patient requires substantial time and cost. The iPSC developed by Song’s team substantially reduces the amount of money and time since it allows culturing of iPSC according to HLA haplotype, differentiates them into various cells, and stores them for use at, later times.

Professor Song also compared and analyzed HLA data around the world through international collaborative research. As a result, the team found that the Korean-derived cell lines can be applied to a large number of Asians, including those from Japan and China, at high frequency.

The top 10 cell lines in Korea consisted of matches with six types from Japan and five types from China. Although somewhat less frequent, it was also relevant to people from various other countries such as the United States, Britain, and Germany. Based on the findings, Professor Song emphasized the need for international cooperation in this field.

"This study has dramatically reduced the time and cost of custom-made cells using inducible pluripotent stem cells,” he said. "Collaboration with various countries such as Japan, China, the U.S. and the U.K. based on the similarity of the HLA haplotype will further enhance its usefulness on an international level.”

Song is serving as the director of the Global Alliance for iPSC Therapies (GAiT) that works for the development and commercialization of iPSC therapies in clinical trials while also serving as the CEO of Korea and Asia. The international consortium is working on the standardization of iPSC manufacturing, quality control, and safety standards.

yjc@docdocdoc.co.kr

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