title: Ex vivo expansion does not alter the capacity of umbilical cord blood CD34+ cells to generate functional T lymphocytes and dendritic cells.
abstract: We examined whether ex vivo expansion of umbilical cord blood progenitor cells affected their capacity to generate immune cells such as T lymphocytes (TLs) and dendritic cells (DCs). The capacity to generate TLs from cord blood CD34(+) cells expanded for 14 days (d14) was compared with that of nonexpanded CD34(+) cells (d0) using fetal thymus organ cultures or transfer into nonobese diabetic/severe combined immunodeficient mice. The cell preparations yielded comparable percentages of immature (CD4(+)CD8(-), CD4(+)CD8(+)) TLs and functional mature (CD3(+)CD4(+), CD3(+)CD8(+)) TLs with an analogous TCR (T-cell receptor)-Vbeta repertoire pattern. As regards DCs, d0 and d14 CD34(+) cells also yielded similar percentages of CD1a(+) DCs with the same expression levels of HLA-DR, costimulatory and adhesion molecules, and chemokine receptors. DCs derived from either d14 or d0 CD34(+) stimulated allogeneic TLs to the same extent, and the cytokine pattern production of these allogeneic TLs was similar with no shift toward a predominant Th1 or Th2 response. Even though the intrinsic capacity of d14 CD34(+) cells to generate DCs was 13-fold lower than that of d0 CD34(+) cells, this reduction was offset by the prior amplification of the CD34(+) cells, resulting in the overall production of 15-fold more DCs. These data indicate that ex vivo expansion of CD34(+) cells does not impair T lymphopoiesis nor DC differentiation capacity.
authors.affiliation: Laboratoire d'Hématologie, Unité de Formation et de Recherche EA1638, Université Pierre et Marie Curie, CHU Saint Antoine, Paris, France.
authors.forename: Ladan
authors.initials: L
authors.lastname: Kobari
authors.forename: Marie C
authors.initials: MC
authors.lastname: Giarratana
authors.forename: Jean C
authors.initials: JC
authors.lastname: Gluckman
authors.forename: Luc
authors.initials: L
authors.lastname: Douay
authors.forename: Michelle
authors.initials: M
authors.lastname: Rosenzwajg
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology*; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009924:Organ Culture Techniques; D010641:Phenotype; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology*
chemical_list: D018952:Antigens, CD34; D016693:Receptors, Antigen, T-Cell, alpha-beta; D007371:Interferon-gamma