title: Implication of delayed TNF-alpha exposure on dendritic cell maturation and expansion from cryopreserved cord blood CD34+ hematopoietic progenitors.
abstract: Most currently used systems for dendritic cell (DC) production from progenitors entail tumor necrosis factor alpha (TNF-alpha) at the onset of cell culture, based on the notion that TNF-alpha might be required in the early stages of DC development. To optimize conditions for DC expansion from cryopreserved cord blood (CB) CD34+ hematopoietic progenitors, we took a dynamic approach to define the timing of TNF-alpha exposure to the culture. We cultured cord blood CD34+ cells in RPMI-1640 with 10% human AB plasma, stem cell factor (days 1-6), granulocyte-macrophage colony-stimulating factor (days 1-18), interleukin-4 (days 6-18) and varying schedules of TNF-alpha (0-144 h after thawing). Expression of the DC-associated markers, including CD83/CD1a, HLA DR/CD86/CD80, CD14/CD40, was monitored every 3 days. Our data demonstrate that delayed TNF-alpha exposure by 48-72 h after thawing gave rise to two- to three-fold increase in the yield of CD83+ DCs that were highly active in stimulating allogeneic T-cell proliferation compared to immediate TNF-alpha exposure. Thus, the immediate exposure of cryopreserved cord blood CD34+ cells to TNF-alpha, potentially compromising DC expansion, should be avoided. This finding should be of significant consideration when using cryopreserved CD34+ progenitor cells as a source of immunologically competent DCs in a clinical setting.
authors.affiliation: Department of Medicine and Long Island Cancer Institute, State University of New York at Stony Brook, NY, USA. rxu@notes.cc.sunysb.edu
authors.forename: Richard Li-Cheng
authors.initials: RL
authors.lastname: Xu
authors.forename: Yingying
authors.initials: Y
authors.lastname: Tang
authors.forename: Paul L
authors.initials: PL
authors.lastname: Ogburn
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Malinowski
authors.forename: Stefan
authors.initials: S
authors.lastname: Madajewicz
authors.forename: Frances
authors.initials: F
authors.lastname: Santiago-Schwarz
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fan
mesh_terms: D018952:Antigens, CD34 / Q000276:immunology; D015415:Biomarkers; D002454:Cell Differentiation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects*; D015925:Cryopreservation; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D005312:Fetal Blood / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000276:immunology; D006801:Humans; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha