title: Ex vivo expansion of G-CSF-mobilized peripheral blood CD133+ progenitor cells on coculture with human stromal cells.
abstract: OBJECTIVE
  The pentaspan molecule CD133 has been shown to be a marker of more primitive hematopoietic progenitors in mobilized peripheral blood (PB). Our objective was to assess the efficacy of PB CD133(+) cells in our coculture system using human telomerized stromal (HTS) cells.
  
  
  METHODS
  Five thousand PB CD133(+) cells or conventional cord blood (CB) CD34(+) cells were expanded with or without HTS cells in the presence or absence of stem cell factor, thrombopoietin, and Flk-2/Flt-3 ligand.
  
  
  RESULTS
  The coculture was significantly superior in expanding PB clonogenic cells as compared with the stroma-free culture (CFU-C, 2 +/- 0 vs 111 +/- 15-fold of initial cell number, p < 0.01), and the fold increase of PB clonogenic cells was comparable to that for CB cells after two weeks of coculture (BFU-E, 54 +/- 3 vs 56 +/- 4-fold; CFU-GM, 156 +/- 26 vs 83 +/- 9-fold; CFU-Mix, 30 +/- 11 vs 80 +/- 36-fold). However, proliferation of CFU-Mk from PB on coculture with HTS cells was modest as compared with stroma-free culture. Concomitantly, multiple hematopoietic cells transmigrated below the stromal layer and formed cobblestone areas (CAs). The production of hematopoietic progenitor cells from CAs after coculture with PB was significantly lower than that seen in cells cocultured with CB for four weeks (CFU-Mix, 0 +/- 0 vs 9 +/- 5-fold on day 28, p < 0.01), although a similar number of CAs derived from PB and CB were observed.
  
  
  CONCLUSIONS
  PB CD133(+) cells proliferated efficiently above the stromal layer, while the characteristics of PB CD133(+) cells underneath the human stromal layer were likely to be maintained, even after long-term hematopoietic-stromal interaction.
authors.affiliation: Fourth Dept. of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawano
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kobune
authors.forename: Hiroki
authors.initials: H
authors.lastname: Chiba
authors.forename: Kiminori
authors.initials: K
authors.lastname: Nakamura
authors.forename: Rishu
authors.initials: R
authors.lastname: Takimoto
authors.forename: Kohichi
authors.initials: K
authors.lastname: Takada
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ito
authors.forename: Junji
authors.initials: J
authors.lastname: Kato
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hamada
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Niitsu
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000096:biosynthesis*; D018952:Antigens, CD34 / Q000096:biosynthesis; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002999:Clone Cells; D018920:Coculture Techniques; D006023:Glycoproteins / Q000096:biosynthesis*; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D010455:Peptides; D017154:Stromal Cells / Q000166:cytology* / Q000187:drug effects
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D016179:Granulocyte Colony-Stimulating Factor