title: Withdrawal of TNF-alpha after the fifth day of differentiation of CD34+ cord blood progenitors generates a homogeneous population of Langerhans cells and delays their maturation.
abstract: Human cord blood CD34+ progenitors cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) generate a heterogeneous population of dendritic cells (DC), including Langerhans cells (LC). This combination of cytokines has been shown to be crucial for differentiation into LC. After day 5 of culture, TNF-alpha has been maintained in the medium in most studies despite the observation of spontaneous maturation of LC after day 12. Five-day samples of in vitro differentiated LC were cultured in parallel with or without TNF-alpha. The absence of TNF-alpha was shown to: (1) slow down proliferation without triggering apoptotic cell death, (2) enhance the percentage of LC, (3) delay or abrogate the expression of CD83, CD86, HLA-DR and CD208 molecules, and (4) maintain endocytosis by receptor and macropinocytosis. The withdrawal of TNF-alpha abrogated the spontaneous synthesis of matrix metalloproteinases. At day 12, TNF-alpha-deprived LC were less efficient in allogeneic T cell activation than LC cultivated with TNF-alpha. These data indicate that the suppression of TNF-alpha after day 5 maintains cells in an immature state and provides a population with 80% of LC at day 12.
authors.affiliation: INSERM Unité 346, Laboratoire de Recherche Peau Humaine et Immunité, Hôpital Edouard Herriot, Lyon, France.
authors.forename: N
authors.initials: N
authors.lastname: Noirey
authors.forename: M-J
authors.initials: MJ
authors.lastname: Staquet
authors.forename: M-J
authors.initials: MJ
authors.lastname: Gariazzo
authors.forename: M
authors.initials: M
authors.lastname: Serres
authors.forename: C
authors.initials: C
authors.lastname: Dezutter-Dambuyant
authors.forename: C
authors.initials: C
authors.lastname: André
authors.forename: D
authors.initials: D
authors.lastname: Schmitt
authors.forename: C
authors.initials: C
authors.lastname: Vincent
mesh_terms: D018952:Antigens, CD34 / Q000097:blood*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D016922:Cellular Senescence; D004334:Drug Administration Schedule; D018093:Gelatinases / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D007801:Langerhans Cells / Q000166:cytology / Q000201:enzymology / Q000502:physiology; D007959:Lymphocyte Culture Test, Mixed; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage*
chemical_list: D018952:Antigens, CD34; D014409:Tumor Necrosis Factor-alpha; D018093:Gelatinases