Evaluation of 28 Human Embryonic Stem Cell Lines for Use as Unrelated Donors in Stem Cell Therapy: Implications of HLA and ABO Genotypes

Abstract

For human embryonic stem cells (hESCs) to be used clinically, it is imperative that immune responses evoked by hESCs and their derivates after transplantation should be prevented. Human leukocyte antigens (HLA) and ABO blood group antigens are important histocompatibility factors in graft rejection. HLA matching between recipient and unrelated donors, in particular, is important in improving outcomes in hematopoietic cell transplantation (HCT). We have established and successfully maintained 29 hESC lines and analyzed the HLA and ABO genotypes of these lines. HLA-A, -B, -C and -DR (DRB1) genotyping was performed by polymerase chain reaction (PCR) sequence-based typing and ABO genotyping was carried out by PCR restriction fragment length polymorphism methods. To determine what proportion of the Korean population would be covered by these cell lines in organ transplantation, 27 cell lines with HLA-A, -B, and -DR data were evaluated for HCT (cord blood) donors and 28 cell lines with HLA-DR and ABO data were evaluated for solid organ (kidney) transplantation donors, and then compared the data with those from 6,740 donated cord bloods. When 2 HLA mismatches are allowed for HCT, as currently accepted for cord blood transplantation, it was estimated that about 16% and 25% of the possible recipients can find one or more donor cell lines with ≤2 mismatches at A, B, DRB1 allele level and at A, B antigen/DRB1 allele level, respectively. When HLA-DR antigen level matching and ABO compatibility was considered for solid organ (kidney) transplantation, it was estimated that about 29% and 96% of the possible recipients can find one or more ABO-compatible donor cell lines with 0 and 1 DR mismatches, respectively. We provided the first report on the HLA and ABO genotypes of hESC lines, and estimated the degree of HLA and ABO matching in organ transplantation for the Korean population.

Do We Need More Human Embryonic Stem Cell Lines?

“…the authors speculate that should the number of embryonic stem cell lines is reduced but the selection of the histocompatibility types is made more stringent and more tailored to the structure of the studied population (more specifically, a selection for stem cell lines who are homozygous for the hlA types which are commonly seen in the population in question), about 10 embryonic stem cell lines may suffice to ensure about the same degree of compatibility. Similar results are reported by lee et al (23) for the Korean population as they conclude that depending on the resolution of hlA typing, a moderately-sized bank of embryonic stem cells containing about 30 human embryonic stem cell lines will serve the needs of about 15-25% of the recipient population (provided that no more than two hlA mismatches are allowed). therefore, to ensure a compatible transplant even for a patient that matches the ethnic profile for most commonly donated embryos, the number of stem cell lines that might constitute a usable inventory is estimated to be between roughly 10 and 200; and that is valid only for a population-sized study.…”

Autophagy Regulates Homeostasis of Pluripotency-Associated Proteins in hESCs

“…Two hESC lines (CHA15-hESC [23], passages 55-85, and H9, passages 50-80) and a human induced pluripotent stem cell (iPSC) line [24] (passages [25][26][27][28][29][30][31][32][33][34][35] were used in this study. They were maintained on Mitomycin C (Sigma-Aldrich, St. Louis, MO, http://www.sigmaaldrich.com)-treated mouse embryonic fibroblasts (mct-MEFs) in the ESC medium at 37 C and 5% CO 2 in air.…”

We heart cultured hearts. A comparative review of methodologies for targeted differentiation and maintenance of cardiomyocytes derived from pluripotent and multipotent stem cells

“…The risks of severe immunological conflicts may also be easier to resolve with cell lines as potential sources for cells and tissues and for transplantation than with donated tissues and organs. It is believed possible that after careful analysis of the distribution of the HLA types in the particular population, the minimal set of cell lines potentially intended to produce differentiated cells for transplantation purposes may be selected specifically so that their HLA types would match with high degree of compatibility (allowing for ≤ 2 mismatches) the HLA characteristics of a significant percentage of the population [2,3].…”