title: Generation of natural killer cells from serum-free, expanded human umbilical cord blood CD34+ cells.
abstract: Natural killer (NK) cells are important effectors of the innate immune system, which exhibits cytolytic activity against infectious agents and tumor cells. NK cells are derived from CD34(+) hematopoietic stem cells (HSCs). Human umbilical cord blood (UCB) has been recognized as a rich source of HSCs. Previously, we have reported an optimized serum-free medium for ex vivo expansion of CD34(+) cells from UCB. In this study, the serum-free, expanded CD34(+) cells were tested to differentiate into NK cells and their induction kinetics. After 5 weeks of induction, the induced NK cells were characterized by analysis of surface antigens, IFN-gamma secretion, and cytotoxicity against K562 cells. The results indicated that NK cells derived from the serum-free, expanded CD34(+) cells exhibited both characteristics and functions of NK cells. Furthermore, the serum-free, expanded CD34(+) cells showed a significantly higher NK cell differentiation potential than freshly isolated CD34(+) cells. NK cells induced from serum-free, expanded CD34(+) cells showed a higher concentration of IFN-gamma secretion and ability of cytotoxicity than those from freshly isolated CD34(+) cells. Therefore, ex vivo-expanded CD34(+) cells in optimized serum-free medium could differentiate into NK cells and provided a promising cell source for immunotherapeutic approaches.
authors.affiliation: Bioresource Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, Taiwan.
authors.forename: I-Ting
authors.initials: IT
authors.lastname: Kao
authors.forename: Chao-Ling
authors.initials: CL
authors.lastname: Yao
authors.forename: Zwe-Ling
authors.initials: ZL
authors.lastname: Kong
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Wu
authors.forename: Tzu-Lin
authors.initials: TL
authors.lastname: Chuang
authors.forename: Shiaw-Min
authors.initials: SM
authors.lastname: Hwang
mesh_terms: D018952:Antigens, CD34 / Q000097:blood*; D002454:Cell Differentiation; D002470:Cell Survival; D003470:Culture Media; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D011247:Pregnancy; D014470:Umbilical Cord / Q000166:cytology*
chemical_list: D018952:Antigens, CD34; D003470:Culture Media