Ex vivo expansion of G-CSF-mobilized peripheral blood CD133+ progenitor cells on coculture with human stromal cells

ObjectiveThe 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.MethodsFive 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.ResultsThe 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 compa