Heterogeneity among human bone marrow-derived mesenchymal stem cells and neural progenitor cells

Department of Internal Medicine II, Division of Hematology and Oncology, University of Tubingen, Otfried-Muller-Str. 10, 72076 Tubingen, Germany. BACKGROUND AND OBJECTIVES: Mesenchymal stem cells (MSC) and neural progenitor cells (NPC) are pluripotent cells. The former can give rise to myocytes, chondrocytes, adipocytes, and osteogenic cells, while the latter can give rise to astrocytes, neurons, and oligodendrocytes. The aim of this study was to analyze and compare the antigen expression patterns of MSC and NPC. DESIGN AND METHODS: Human bone marrow-derived MSC and NPC were analyzed by flow cytometry and immunocytochemistry using a variety of unique monoclonal antibodies (57D2, W4A5, W8B2) generated in our laboratory. In addition, the expression profile of CD antigens and intracellular differentiation markers was analyzed. RESULTS. We show for the first time that CD10+, CD13+, CD61+, CD90+, CD105 (endoglin)+, CD45-, CD34-, and CD133- MSC also expressed CD109, CD140b (PDGF-RB), CD164, and CD172a (SIRPa). In addition, we found heterogeneity of MSC as demonstrated by the preferential expression of nestin and W8B2 antigen on distinct MSC subpopulations. Morphologically, these populations comprised small single cells and larger cells with polygonal appearance. NPC expressed high levels of CD56, CD90 and nestin and moderate levels of CD15, W4A5, and 57D2 antigens. In contrast, CD133 and CD172 were found only on NPC subpopulations. INTERPRETATION AND CONCLUSIONS: Our data demonstrate nestin expression in most NPC as well as in immature MSC subpopulations. MSC and NPC subpopulations can now be distinguished using our novel antibodies W8B2, 57D2, and W4A5.