%0 Journal Article %T Immediate Exposure to TNF-α Activates Dendritic Cells Derived from Non-Purified Cord Blood Mononuclear Cells %J Iranian Journal of Immunology %I Shiraz Institute for Cancer Research %Z 1735-1383 %A Ebrahimi, Marzieh %A Hassan, Zuhair Mohammad %A Hadjati, Jamshid %A Hayat, Parisa %A Moazzeni, Seyed Mohammad %D 2009 %\ 09/01/2009 %V 6 %N 3 %P 107-118 %! Immediate Exposure to TNF-α Activates Dendritic Cells Derived from Non-Purified Cord Blood Mononuclear Cells %K Dendritic Cells %K TNF-α %K Cord blood %R %X Background: Tumor necrosis factor alpha (TNF-α) is a primary mediator of immune regulation and might be required in the early stages of DC development from CD34+ cells. However, details of optimal timing of exposure to TNF-α in DC development process in monocytes or non-purified hematopoitic cells are still lacking and clear benefits of this approach to the development of DCs remain to be validated. Objective: To evaluate the effect of early and late exposure to TNF-α on DC devel-opment from non-purified cord blood mononuclear cells. Methods: To define the ef-fects of early exposure to TNF-α on cord blood mononuclear cells, we cultured UCB-MNC in the presence of SCF, Flt3L, GM-CSF and IL-4 for 14 days and matured them for an extra 4 days. TNF-α was added on day 0, 7 and 14 in TNF-α + group, and only on day 14 in TNF-α - group where it was used only as a maturation factor. Results: Immediate exposure to TNF-α was shown to: (1) enhance the survival of cells in the first week of culture; (2) produce mature DCs with higher maturation markers (CD80, CD83, CD86 and HLA-DR); and (3) increase secretion of IL-12 by mature DCs. In contrast, delayed exposure to TNF-α stimulate mature DCs with less purity producing a high level of IL-10 and a low level of IL-12. Conclusion: We developed a simple, easy and cost effective method to generate DCs from non-fractionating mononuclear cells in this study. Also we confirm the presence of a large number of functional DCs under inflammatory conditions, where local concentrations of TNF-α were high. %U https://iji.sums.ac.ir/article_17082_5a7960f5ae4f236d3742e0a04a741552.pdf