ISSN:
1600-0625
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Medizin
Notizen:
Abstract: Human cord blood CD34+ progenitors cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) 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-α 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-α. The absence of TNF-α was shown to: (1) slow down proliferation without triggering apoptotic cell death, (2) enhance the percentage of LC, (3) delay or abrogat the expression of CD83, CD86, HLA-DR and CD208 molecules, and (4) maintain endocytosis by receptor and macropinocytosis. The withdrawal of TNF-α abrogated the spontaneous synthesis of matrix metalloproteinases. At day 12, TNF-α-deprived LC were less efficient in allogeneic T cell activation than LC cultivated with TNF-α. These data indicate that the suppression of TNF-α after day 5 maintains cells in an immature state and provides a population with 80% of LC at day 12.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1034/j.1600-0625.2003.00043.x
