Ebrahimi Marzieh, Hassan Zuhair Mohammad, Hadjati Jamshid, Hayat Parisa, Moazzeni Seyed Mohammad
Department of Immunology, Tarbiat Modares University, Tehran, Iran.
Iran J Immunol. 2009 Sep;6(3):107-18.
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.
To evaluate the effect of early and late exposure to TNF-alpha on DC development from non-purified cord blood mononuclear cells.
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.
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.
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.
肿瘤坏死因子α（TNF-α）是免疫调节的主要介质，可能在CD34+细胞向树突状细胞（DC）发育的早期阶段发挥作用。然而，在单核细胞或未纯化的造血细胞的DC发育过程中，接触TNF-α的最佳时间细节仍不清楚，这种方法对DC发育的明显益处仍有待验证。
评估早期和晚期接触TNF-α对未纯化脐血单个核细胞DC发育的影响。
为了确定早期接触TNF-α对脐血单个核细胞的影响，我们在干细胞因子（SCF）、Flt3配体（Flt3L）、粒细胞-巨噬细胞集落刺激因子（GM-CSF）和白细胞介素-4（IL-4）存在的情况下培养脐血单个核细胞14天，并使其再成熟4天。TNF-α+组在第0、7和14天添加TNF-α，而TNF-α-组仅在第14天添加，此时它仅用作成熟因子。
结果显示，立即接触TNF-α可：（1）提高培养第一周细胞的存活率；（2）产生具有更高成熟标志物（CD80、CD83、CD86和人类白细胞抗原-DR（HLA-DR））的成熟DC；（3）增加成熟DC分泌白细胞介素-12（IL-12）。相比之下，延迟接触TNF-α会刺激纯度较低的成熟DC产生高水平的IL-10和低水平的IL-12。
在本研究中，我们开发了一种简单、易行且经济高效的方法，从未分级的单个核细胞中生成DC。我们还证实，在炎症条件下，即局部TNF-α浓度较高时，存在大量功能性DC。
