Immediate exposure to TNF-alpha activate dendritic cells derived from non-purified cord blood mononuclear cells.
BACKGROUND
Tumor necrosis factor alpha (TNF-alpha) 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-alpha 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-alpha on DC development from non-purified cord blood mononuclear cells.


METHODS
To define the effects of early exposure to TNF-alpha 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-alpha was added on day 0, 7 and 14 in TNF-alpha + group, and only on day 14 in TNF-alpha - group where it was used only as a maturation factor.


RESULTS
Immediate exposure to TNF-alpha 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-alpha stimulate mature DCs with less purity producing a high level of IL-10 and a low level of IL-12.


CONCLUSIONS
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-alpha were high.
Department of Immunology, Tarbiat Modares University, Tehran, Iran. ebrahimi@royaninstitute.org
Marzieh
M
Ebrahimi
Zuhair Mohammad
ZM
Hassan
Jamshid
J
Hadjati
Parisa
P
Hayat
Seyed Mohammad
SM
Moazzeni
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D015703:Antigens, CD / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005312:Fetal Blood / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis / Q000276:immunology; D018664:Interleukin-12 / Q000096:biosynthesis / Q000276:immunology; D015847:Interleukin-4 / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000276:immunology; D008565:Membrane Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000276:Adjuvants, Immunologic; D015703:Antigens, CD; C508609:IL10 protein, human; C508598:IL4 protein, human; D008565:Membrane Proteins; D014409:Tumor Necrosis Factor-alpha; C084881:flt3 ligand protein; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor