title: The potential of human peripheral blood derived CD34+ cells for ex vivo red blood cell production.
abstract: The potential of peripheral blood derived CD34+ cells for ex vivo erythropoiesis was investigated in a stroma-free culture system using a novel strategy of daily passaging. By expanding PB-derived CD34+ cells up to 1.5 x 10(6)-fold this method achieved expansion factors previously only reported for CD34+ cells derived from more potent stem cell sources such as cord blood, bone marrow and mobilized peripheral blood. Analysis of cell surface markers showed differentiation of immature CD34+ cells to populations with 80% CD71-/GpA+ cells and up to 45% enucleated cells, indicating a significant amount of terminal maturation. Cell crowdedness was found to have decisive effects on in vitro erythropoiesis. Cell density per surface area rather than cell concentration per media volume determined cell expansion during exponential growth where more crowded cells showed reduced overall expansion. In late stage erythropoiesis, however, when cells no longer proliferating, increased cell density was seen to enhance cell viability. These results indicate that peripheral blood derived haematopoietic stem cells can be an alternative to cells sourced from bone marrow, cord blood or leukapheresis in terms of expansion potential. This provides distinct advantages in terms of availability for studies of conditions for scale-up and maturation, and may have particular clinical applications in the future.
authors.affiliation: School of Chemical and Bioprocess Engineering, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.
authors.forename: Daniela
authors.initials: D
authors.lastname: Boehm
authors.forename: William G
authors.initials: WG
authors.lastname: Murphy
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Rubeai
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism*; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods*; D002453:Cell Cycle; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D002470:Cell Survival; D016207:Cytokines / Q000302:isolation & purification; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D011990:Receptors, Transferrin / Q000378:metabolism; D014343:Trypan Blue
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; C068126:CD71 antigen; D016207:Cytokines; D011990:Receptors, Transferrin; D019009:Proto-Oncogene Proteins c-kit; D014343:Trypan Blue