Human circulating CD14+ monocytes as a source of progenitors that exhibit mesenchymal cell differentiation

J Leukoc Biol. 2003 Nov;74(5):833-45. doi: 10.1189/jlb.0403170. Epub 2003 Jul 22.


Circulating CD14+ monocytes are precursors of phagocytes, such as macrophages and dendritic cells. Here we report primitive cells with a fibroblast-like morphology derived from human peripheral blood CD14+ monocytes that can differentiate into several distinct mesenchymal cell lineages. We named this cell population monocyte-derived mesenchymal progenitor (MOMP). MOMPs were obtained in vitro from human peripheral blood mononuclear cells cultured on fibronectin in the presence of fetal bovine serum alone as a source of growth factors. MOMPs had a unique molecular phenotype-CD14+CD45+CD34+type I collagen+-and showed mixed morphologic and molecular features of monocytes and endothelial and mesenchymal cells. MOMPs were found to be derived from a subset of circulating CD14+ monocytes, and their differentiation required that they bind fibronectin and be exposed to one or more soluble factors derived from peripheral blood CD14- cells. MOMPs could be expanded in culture without losing their original phenotype for up to five passages. The induction of MOMPs to differentiate along multiple limb-bud mesodermal lineages resulted in the expression of genes and proteins specific for osteoblasts, skeletal myoblasts, chondrocytes, and adipocytes. Our findings represent the first evidence that human circulating CD14+ monocytes are a source of progenitors that exhibit mesenchymal cell differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / blood
  • Azacitidine / pharmacology
  • Base Sequence
  • Calcium / blood
  • Cell Adhesion / drug effects
  • Cell Differentiation
  • Cells, Cultured
  • DNA Primers
  • Dendritic Cells / cytology
  • Dendritic Cells / immunology
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / immunology*
  • Humans
  • Leukocytes, Mononuclear / cytology
  • Leukocytes, Mononuclear / immunology
  • Lipopolysaccharide Receptors / blood*
  • Lipopolysaccharide Receptors / genetics
  • Lipoproteins, LDL / blood
  • Macrophages / cytology
  • Macrophages / immunology
  • Mesoderm / cytology*
  • Mesoderm / immunology
  • Monocytes / cytology
  • Monocytes / immunology*
  • Osteogenesis / drug effects
  • Osteogenesis / physiology
  • Polymerase Chain Reaction


  • DNA Primers
  • Lipopolysaccharide Receptors
  • Lipoproteins, LDL
  • acetyl-LDL
  • Alkaline Phosphatase
  • Azacitidine
  • Calcium