The impact of progenitor enrichment, serum, and cytokines on the ex vivo expansion of mobilized peripheral blood stem cells: a controlled trial

Stem Cells. 2003;21(1):33-40. doi: 10.1634/stemcells.21-1-33.

Abstract

The aim of this study was to verify, and possibly improve, culture conditions to expand human mobilized peripheral blood stem cells (PBSCs). We investigated the role of three parameters: A) the culture medium (serum-free versus serum-dependent); B) the initial cell population (Ficoll-separated mononucleated cells versus CD34(+)-selected cells), and C) the low concentration of recombinant cytokines, flt3 ligand, and thrombopoietin in association with a basic cocktail of stem cell factor, interleukin (IL)-6, IL-3, GM-CSF, and erythropoietin. Eighteen leukapheresis samples were monitored in static culture for 15 days. The expansion potential was assessed at day 10 and 15 by total nuclear cells, colony-forming-units (CFUs) (burst-forming units-erythroid [BFU-E], colony-forming units-granulocyte-macrophage [CFU-GM], and colony-forming units-granulocyte-erythroid-macrophage-megakaryocyte [CFU-GEMM]), and flow cytometry immunophenotyping (CD34(+)/CD38(-), CD38(+), CD33(+), CD41(+), GlyA(+) progenitor cells). The results, evaluated by multivariate analysis of variance, emphasize that some variables affected the outcome of stem and progenitor cell expansion. CD34(+) enrichment increased expansion of total nuclear cells, number of CD38(+) and CD33(+) late precursors, and number of the CFU-GM compartment. Interestingly, however, quantitative expansion of GlyA(+) and the early progenitor cells (CD34(+)/CD38(-), CFU-GEMM, BFU-E) are favored by the use of unselected mononucleated cells. Regarding the role of serum, no significant difference was observed except for expansion of total nuclear cells, CFU-GM, and BFU-E. Cytokine combinations, in particular the use of flt3 ligand, stimulated expansion of almost all the cellular subsets, reaching a statistical significance for total nuclear cells and CFU-GM. Our study indicates that progenitor and late precursor multilineage cell compartments of mobilized PBSCs may be significantly expanded in short-term cultures by well-defined experimental conditions. Furthermore, these data might be useful when evaluating ex vivo expansion of hematopoietic cells for clinical purposes.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Culture Techniques / methods
  • Cell Division / physiology
  • Cell Separation / methods
  • Cells, Cultured
  • Cytokines / physiology*
  • Female
  • Hematopoietic Stem Cell Mobilization / methods*
  • Humans
  • Immunophenotyping
  • Leukocytes, Mononuclear / chemistry
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Peripheral Blood Stem Cell Transplantation / methods
  • Stem Cells / chemistry
  • Stem Cells / drug effects
  • Stem Cells / physiology*

Substances

  • Cytokines