title: Sustained macroscopic engraftment of cynomolgus embryonic stem cells in xenogeneic large animals after in utero transplantation.
abstract: Because embryonic stem (ES) cells are able to proliferate indefinitely and differentiate into any type of cell, they have the potential for providing an inexhaustible supply of transplantable cells or tissues. However, methods for the in vitro differentiation of human ES cells are still quite limited. One possible strategy would be to generate differentiated cells in vivo. In view of future clinical application, we investigated the possibility of using xenogeneic large animals for this purpose. We transplanted nonhuman primate cynomolgus ES cells into fetal sheep at 43-67 gestational days (full term 147 days, n=15). After birth, cynomolgus tissues, which were mature teratomas, had been engrafted in sheep when more than 1 x 10(6) ES cells were transplanted at <50 gestational days. Despite the sustained engraftment, both cellular and humoral immune responses against the ES cells were detected, and additional transplantation was not successful in the animals. At 2 weeks post-transplantation, the ES cell progeny proliferated when transplanted at 48 (<50) gestational days, whereas they were cleared away when transplanted at 60 (>50) gestational days. These results support the rapid development of the xenogeneic immunological barrier in fetal sheep after 50 gestational days. Notably, a large number of Foxp3(+) regulatory T cells were present around the ES cell progeny, but macrophages were absent when the transplant was conducted at <50 gestational days, implying that regulatory T cells and premature innate immunity might have contributed to the sustained engraftment. In conclusion, long-term macroscopic engraftment of primate ES cells in sheep is feasible despite the xenogeneic immunological barrier.
authors.affiliation: Division of Regenerative Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi 329-0498, Japan.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shibata
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kishi
authors.forename: Tamako
authors.initials: T
authors.lastname: Ikeda
authors.forename: Shigeo
authors.initials: S
authors.lastname: Masuda
authors.forename: Kyoko
authors.initials: K
authors.lastname: Sasaki
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Abe
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hayashi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kitano
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Nagao
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hanazono
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004624:Embryo Transfer / Q000379:methods; D004622:Embryo, Mammalian; D047108:Embryonic Development / Q000235:genetics; D053595:Embryonic Stem Cells / Q000502:physiology / Q000637:transplantation*; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D006085:Graft Survival; D007113:Immunity, Innate / Q000235:genetics / Q000502:physiology; D008252:Macaca fascicularis; D008969:Molecular Sequence Data; D011247:Pregnancy; D012756:Sheep / Q000196:embryology; D018183:Transplantation Chimera; D014181:Transplantation Immunology; D014183:Transplantation, Heterologous; D014599:Uterus / Q000502:physiology
chemical_list: D051858:Forkhead Transcription Factors