title: Ex vivo expanded umbilical cord blood T cells maintain naive phenotype and TCR diversity.
abstract: BACKGROUND
  Umbilical cord blood (CB) is a promising source of hematopoietic stem cells for allogeneic transplantation. However, delayed engraftment and impaired immune reconstitution remain major limitations. Enrichment of donor grafts with CB T cells expanded ex vivo might facilitate improved T-cell immune reconstitution post-transplant. We hypothesized that CB T cells could be expanded using paramagnetic microbeads covalently linked to anti-CD3 and anti-CD28 Ab.
  
  
  METHODS
  CB units were divided into three fractions: (1) cells cultured without beads, (2) cells cultured with beads and (3) cells cultured with beads following CD3+ magnetic enrichment. All fractions were cultured for 14 days in the presence of IL-2 (200 IU/mL).
  
  
  RESULTS
  A mean 100-fold expansion (range 49-154) of total nucleated cells was observed in the CD3+ magnetically enriched fraction. Following expansion, CB T cells retained a naive and/or central memory phenotype and contained a polyclonal TCR diversity demonstrated by spectratyping.
  
  
  CONCLUSIONS
  Our data provide evidence that naive and diverse CB T cells may be expanded ex vivo and warrant additional studies in the setting of human CB transplantation.
authors.affiliation: The Department of Blood and Marrow Transplantation, MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: S
authors.initials: S
authors.lastname: Parmar
authors.forename: S N
authors.initials: SN
authors.lastname: Robinson
authors.forename: K
authors.initials: K
authors.lastname: Komanduri
authors.forename: L
authors.initials: L
authors.lastname: St John
authors.forename: W
authors.initials: W
authors.lastname: Decker
authors.forename: D
authors.initials: D
authors.lastname: Xing
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.forename: J
authors.initials: J
authors.lastname: McMannis
authors.forename: R
authors.initials: R
authors.lastname: Champlin
authors.forename: M
authors.initials: M
authors.lastname: de Lima
authors.forename: J
authors.initials: J
authors.lastname: Molldrem
authors.forename: A
authors.initials: A
authors.lastname: Rieber
authors.forename: M
authors.initials: M
authors.lastname: Bonyhadi
authors.forename: R
authors.initials: R
authors.lastname: Berenson
authors.forename: E J
authors.initials: EJ
authors.lastname: Shpall
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D018106:CD28 Antigens / Q000378:metabolism; D017252:CD3 Complex / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D002478:Cells, Cultured; D036101:Cord Blood Stem Cell Transplantation; D005312:Fetal Blood / Q000166:cytology*; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D018106:CD28 Antigens; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell