title: [Expansion of human natural killer cells ex vivo].
abstract: OBJECTIVE
  To obtain sufficient numbers of pure and activated human primary NK cells for potential clinical application.
  
  
  METHODS
  PBMC based ex vivo expansion of natural killer cells was set up. The expansion was initiated by co-culture of PBMC and stimulator cells (irradiate genetic modified K562 cells) in RPMI1640 medium with 1 000 U/mL IL-2. Genetic modified K562 cells 'K562D3' were prepared by expressing IL-15, 4-1BBL and IL-18 on K562 cell membrane.
  
  
  RESULTS
  An average of 500 fold expansion of CD56(+)CD3(-) cells was observed after 3 weeks of co-culture. The NK cells population could reach 93% after expansion, comparing with 7% before expansion. The expanded NK cells lysed 95% of K562 targets in a 5:1 effector to target ratio. IL-15/4-1BBL bound K562 stimulatory cells could expand same fold NK cells as K562D3, but the cytotoxicity of NK cells expanded by 'K562D3' was 10% higher.
  
  
  CONCLUSIONS
  The described method is a simple and efficient way for the expansion of human NK cells.
authors.affiliation: Key Laboratory for Space Biosciences & Biotechnology, Faculty of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China. qingshengh@yahoo.com.cn
authors.forename: Qing-Sheng
authors.initials: QS
authors.lastname: Huang
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Peng
authors.initials: P
authors.lastname: Shang
authors.forename: Ming-Jie
authors.initials: MJ
authors.lastname: Zhang
mesh_terms: D053330:4-1BB Ligand / Q000235:genetics / Q000378:metabolism; D000328:Adult; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D019409:Interleukin-15 / Q000235:genetics / Q000378:metabolism; D020382:Interleukin-18 / Q000235:genetics / Q000378:metabolism; D007376:Interleukin-2 / Q000494:pharmacology; D020014:K562 Cells / Q000378:metabolism / Q000502:physiology; D007694:Killer Cells, Natural / Q000166:cytology* / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D053330:4-1BB Ligand; D019409:Interleukin-15; D020382:Interleukin-18; D007376:Interleukin-2