The expansion of megakaryocyte progenitors from CD34+-enriched mobilized peripheral blood stem cells is inhibited by Flt3-L

J Interferon Cytokine Res. 2006 Feb;26(2):76-82. doi: 10.1089/jir.2006.26.76.

Abstract

This study aimed to determine the optimal growth factor combination for expansion of megakaryocyte (Mk) progenitors with clonogenic potential from CD34+-enriched mobilized peripheral blood stem cells (PBSC). Mobilized PBSC were monocyte depleted and CD34+ enriched, then cultured with various combinations of interleukin-3 (IL-3), IL-6, IL-11, Flt3 ligand (Flt3-L), stem cell factor (SCF), granulocyte-macrophage colonystimulating factor (GM-CSF), and erythropoietin (EPO), using a 2(7-3) IV fractional factorial design. Expansion of Mk committed progenitors (CD41+) and primitive precursors (CD61+ CD34+) was determined using FACS and colony-forming assays. Amplification of Mk progenitor production was attributed to IL-3 (p < 0.002), SCF (p < 0.001), and GM-CSF (p < 0.05). Flt3-L inhibited the production of total CD61+ cells (p < 0.05), CD61+CD34+ cells (p < 0.03), and total CD41a+ cells (p < 0.01). Addition of Flt3-L to the optimum growth factor combination of megakaryocyte growth and development factor (MGDF), SCF, IL-3, and GM-CSF caused the greatest increase in total nucleated cells but reduced Mk progenitor expansion. There was also a 20% reduction in Mk+ colonies from cells expanded in the presence of Flt3-L. Factorial analysis identified the optimal combination of growth factors required to expand Mk precursors with clonogenic potential. The addition of Flt3-L to the optimal combination of MGDF, SCF, IL-3, and GM-CSF reduced both the fold expansion of Mk progenitors and Mk colony numbers.

MeSH terms

  • Antigens, CD34 / biosynthesis*
  • Antigens, CD34 / blood
  • Cell Differentiation / physiology*
  • Cell Proliferation
  • Cells, Cultured
  • Clone Cells
  • Colony-Forming Units Assay
  • Factor Analysis, Statistical
  • Granulocyte-Macrophage Colony-Stimulating Factor / blood
  • Granulocyte-Macrophage Colony-Stimulating Factor / physiology
  • Growth Inhibitors / blood
  • Growth Inhibitors / physiology*
  • Hematopoietic Stem Cell Mobilization* / statistics & numerical data
  • Hematopoietic Stem Cells / cytology
  • Hematopoietic Stem Cells / metabolism
  • Hematopoietic Stem Cells / physiology*
  • Humans
  • Interleukin-3 / blood
  • Interleukin-3 / physiology
  • Ligands
  • Megakaryocytes / cytology
  • Megakaryocytes / metabolism*
  • Megakaryocytes / physiology
  • Membrane Proteins / blood
  • Membrane Proteins / physiology*
  • Stem Cell Factor / blood
  • Stem Cell Factor / physiology
  • Thrombopoietin / blood
  • Thrombopoietin / physiology

Substances

  • Antigens, CD34
  • Growth Inhibitors
  • IL3 protein, human
  • Interleukin-3
  • Ligands
  • Membrane Proteins
  • Stem Cell Factor
  • flt3 ligand protein
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Thrombopoietin