title: Mesenchymal stem cells promote a primitive phenotype CD34+c-kit+ in human cord blood-derived hematopoietic stem cells during ex vivo expansion.
abstract: The purpose of this study was to evaluate the influence of bone marrow-mesenchymal stem cells (BM-MSC) and exogenously added cytokines on the proliferation, primitive cell subpopulation maintenance (including the c-kit+ marker) and clonogenic capacity of hematopoietic stem cells (HSC). BM-MSC were collected from volunteer donors, isolated and characterized. Umbilical cord blood (UCB) samples were collected from healthy full-term deliveries. UCB-CD34+ cells were cultured in the presence or absence of BM-MSC and/or cytokines for 3 and 7 days. CD34+ cell proliferation was evaluated using the CSFE method and cell phenotype was determined by CD34, c-kit, CD33, CD38, HLA-DR, cyCD22 and cyCD3 detection. Cell clonogenic ability was also assessed. Exogenously added SCF, TPO and FLT3L increased CD34+ cell proliferation in the presence or absence of BM-MSC, but with concomitant cell differentiation. Without any added cytokines, BM-MSC are able to increase the percentage of primitive progenitors as evaluated by c-kit expression and CFU-GEMM increase. Interestingly, this latter effect was dependent on both cell-cell interactions and secreted factors. A 7-day co-culture period will be optimal for obtaining an increased primitive HSC level. Including c-kit as a marker for primitive phenotype evaluation has shown the relevance of BM-MSC and their secreted factors on UCB-HSC stemness function. This effect could be dissociated from that of the addition of exogenous cytokines, which induced cellular differentiation instead.
authors.affiliation: Grupo de Inmunobiología y Biología Celular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Viviana M
authors.initials: VM
authors.lastname: Rodríguez-Pardo
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Vernot
mesh_terms: D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D018920:Coculture Techniques; D005312:Fetal Blood / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D016130:Immunophenotyping; D008565:Membrane Proteins / Q000494:pharmacology; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D023461:Myeloid Progenitor Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D019089:Stem Cell Factor / Q000494:pharmacology; D013926:Thrombopoietin / Q000494:pharmacology
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D008565:Membrane Proteins; D019089:Stem Cell Factor; C084881:flt3 ligand protein; D013926:Thrombopoietin; D019009:Proto-Oncogene Proteins c-kit