title: In vitro proliferation and differentiation of human CD34+ cells from peripheral blood into mature red blood cells with two different cell culture systems.
abstract: BACKGROUND
  An in vitro erythropoiesis assay is a powerful tool for investigating red blood cell (RBC) development and diseases of the erythroid lineage. Most assays, however, failed in either proliferation or terminal differentiation. Here two liquid cultures (LCs) for in vitro generation of RBCs from peripheral blood CD34+ cells were compared.
  
  
  METHODS
  Granulocyte-colony-stimulating factor-mobilized CD34+ cells were cultured for 16 days in a two-phase LC (2P-LC; Days 1-8, stem cell factor [SCF], erythropoietin [EPO], insulinlike growth factor [IGF]-1, and steroids; Days 9-16, EPO and insulin) and for 21 days in a three-phase LC (3P-LC; Days 1-7, SCF, thrombopoetin, and Flt3-ligand; Days 8-14, SCF, EPO, and IGF-1; Days 15-21, EPO and IGF-1). Maturation was analyzed by flow cytometry (CD36, CD71, glycophorin A [GPA]) and microscopy.
  
  
  RESULTS
  In the 2P-LC, cell numbers increased from 0.5 x 10(6) to 25.7 x 10(6) +/- 15.1 x 10(6) cells per mL. More than 95 percent were GPA+ and showed morphologic characteristics of normoblasts (52 +/- 15%) and enucleated reticulocytes (43 +/- 18%). In the 3P-LC, a higher overall proliferation to 55.7 x 10(6) +/- 37.7 x 10(6) cells per mL was achieved (p < 0.05). This was also accompanied by a high degree of normoblasts (36 +/- 16%) and reticulocytes (48 +/- 24%). The amount of GPA+ cells was slightly lower (88.4 +/- 16.4%), associated with a significantly higher contamination by nonerythroid cells (15.8 +/- 19.3% vs. 3.9 +/- 2.9%, p < 0.05).
  
  
  CONCLUSIONS
  Both LCs were able to generate fully matured RBCs and represent powerful tools for fundamental research in erythroid development and diseases targeting the erythroid lineage. A slightly higher proliferation was achieved in the 3P-LC. This was associated with a limited homogeneity due to more nonerythroid cells, however. Therefore the 2P-LC is favored, also saving additional culture days and growth factors.
authors.affiliation: Institute of Immunology and Transfusion Medicine, University of Luebeck, Campus Luebeck, Luebeck, Germany. dorn@immu.mu-luebeck.de
authors.forename: Isabel
authors.initials: I
authors.lastname: Dorn
authors.forename: Pamela
authors.initials: P
authors.lastname: Lazar-Karsten
authors.forename: Stefanie
authors.initials: S
authors.lastname: Boie
authors.forename: Julika
authors.initials: J
authors.lastname: Ribbat
authors.forename: Dirk
authors.initials: D
authors.lastname: Hartwig
authors.forename: Birgit
authors.initials: B
authors.lastname: Driller
authors.forename: Holger
authors.initials: H
authors.lastname: Kirchner
authors.forename: Peter
authors.initials: P
authors.lastname: Schlenke
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism*; D015415:Biomarkers; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation; D018920:Coculture Techniques; D003114:Colony-Forming Units Assay; D004912:Erythrocytes / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D007962:Leukocytes / Q000166:cytology* / Q000378:metabolism*
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers