title: Generation of hematopoietic stem cells from human embryonic stem cells using a defined, stepwise, serum-free, and serum replacement-free monolayer culture method.
abstract: BACKGROUND
  Embryonic stem cells (ESCs) can be expanded infinitelyin vitroand have the potential to differentiate into hematopoietic stem cells (HSCs); thus, they are considered a useful source of cells for HSC production. Although several technicalin vitromethods for engineering HSCs from pluripotent stem cells have been developed, clinical application of HSCs engineered from pluripotent stem cells is restricted because of the possibility of xenogeneic contamination resulting from the use of murine materials.
  
  
  METHODS
  Human ESCs (CHA-hES15) were cultured on growth factor-reduced Matrigel-coated dishes in the mTeSR1 serum-free medium. When the cells were 70% confluent, we initiated HSC differentiation by three methods involving (1) knockout serum replacement (KSR), cytokines, TGFb1, EPO, and FLT3L; (2) KSR, cytokines, and bFGF; or (3) cytokines and bFGF.
  
  
  RESULTS
  Among the three differentiation methods, the minimal number of cytokines without KSR resulted in the greatest production of HSCs. The optimized method resulted in a higher proportion of CD34+CD43+hematopoietic progenitor cells (HPCs) and CD34+CD45+HPCs compared to the other methods. In addition, the HSCs showed the potential to differentiate into multiple lineages of hematopoietic cellsin vitro.
  
  
  CONCLUSIONS
  In this study, we optimized a two-step, serum-free, animal protein-free, KSR-free, feeder-free, chemically defined monolayer culture method for generation of HSCs and hematopoietic stem and progenitor cells (HSPCs) from human ESCs.
authors.affiliation: Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health and Korea Centers for Diseases Control and Prevention, Cheongju, Korea.; Department of Biochemistry, College of Medicine, Chungbuk National University, Cheongju, Korea.
authors.forename: So-Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health and Korea Centers for Diseases Control and Prevention, Cheongju, Korea.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Jung
authors.affiliation: Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health and Korea Centers for Diseases Control and Prevention, Cheongju, Korea.
authors.forename: Hye-Yeong
authors.initials: HY
authors.lastname: Ha
authors.affiliation: Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health and Korea Centers for Diseases Control and Prevention, Cheongju, Korea.
authors.forename: Soo Kyung
authors.initials: SK
authors.lastname: Koo
authors.affiliation: Department of Biochemistry, College of Medicine, Chungbuk National University, Cheongju, Korea.
authors.forename: Eung-Gook
authors.initials: EG
authors.lastname: Kim
authors.affiliation: Division of Intractable Diseases, Center for Biomedical Sciences, National Institute of Health and Korea Centers for Diseases Control and Prevention, Cheongju, Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
keywords: Hematopoietic differentiation; Pluripotent stem cell; Xeno-free protocol