title: Human CD34+ cell preparations contain over 100-fold greater NOD/SCID mouse engrafting capacity than do CD34- cell preparations.
abstract: OBJECTIVE
  The CD34 cell surface marker is used widely for stem/progenitor cell isolation. Since several recent studies reported that CD34(-) cells also have in vivo engrafting capacity, we quantitatively compared the engraftment potential of CD34(+) vs CD34(-) cell preparations from normal human placental/umbilical cord blood (CB), bone marrow (BM), and mobilized peripheral blood (PBSC) specimens, using the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model.
  
  
  METHODS
  CD34(+) and CD34(-) cell preparations were purified by four different approaches in 14 individual experiments involving 293 transplanted NOD/SCID mice. In most experiments, CD34(+) cells were depleted twice (CD34(=)) in order to obtain efficient depletion of CD34(+) cells from the CD34(-) cell preparations.
  
  
  RESULTS
  Dose-dependent levels of human hematopoietic cells were observed after transplantation of CD34(+) cell preparations. To rigorously assess the complementary CD34(-) cell preparations, cell doses 10- to 1000-fold higher than the minimum dose of the CD34(+) cell preparations necessary for engraftment were transplanted. Nevertheless, of 125 NOD/SCID mice transplanted with CD34(-) cell preparations purified from the same starting cells, only six mice had detectable human hematopoiesis, by flow cytometric or PCR assay.
  
  
  CONCLUSIONS
  CD34(-) cells provide only a minor contribution to hematopoietic engraftment in this in vivo model system, as compared to CD34(+) cells from the same samples of noncultured human cells. Hematopoiesis derived from actual CD34(-) cells is difficult to distinguish from that due to CD34(+) cells potentially contaminating the preparations.
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Z
authors: Z
authors: Gao
authors: M J
authors: MJ
authors: Fackler
authors: W
authors: W
authors: Leung
authors: R
authors: R
authors: Lumkul
authors: M
authors: M
authors: Ramirez
authors: N
authors: N
authors: Theobald
authors: H L
authors: HL
authors: Malech
authors: C I
authors: CI
authors: Civin
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000096:biosynthesis / Q000276:immunology*; D015415:Biomarkers; D006085:Graft Survival / Q000276:immunology*; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D014184:Transplantation, Homologous
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers