Brawand Pierre, Fitzpatrick David R, Greenfield Brad W, Brasel Kenneth, Maliszewski Charles R, De Smedt Thibaut
Amgen Inc., Seattle, WA 98101, USA.
J Immunol. 2002 Dec 15;169(12):6711-9. doi: 10.4049/jimmunol.169.12.6711.
The putative counterparts of human plasmacytoid pre-dendritic cells (pDCs) have been described in vivo in mouse models and very recently in an in vitro culture system. In this study, we report that large numbers of bone marrow-derived murine CD11c(+)B220(+) pDCs can be generated with Flt3 ligand (FL) as the sole exogenous differentiation/growth factor and that pDC generation is regulated in vivo by FL because FL-deficient mice showed a major reduction in splenic pDC numbers. We extensively analyzed bone marrow-derived CD11c(+)B220(+) pDCs and described their immature APC phenotype based on MHC class II, activation markers, and chemokine receptor level of expression. CD11c(+)B220(+) pDCs showed a nonoverlapping Toll-like receptor pattern of expression distinct from that of classical CD11c(+)B220(-) dendritic cells and were poor T cell stimulators. Stimulation of CD11c(+)B220(+) pDCs with oligodeoxynucleotides containing certain CpG motifs plus CD40 ligand plus GM-CSF led to increased MHC class II, CD80, CD86, and CD8alpha expression levels, to a switch in chemokine receptor expression that affected their migration, to IFN-alpha and IL-12 secretion, and to the acquisition of priming capacities for both CD4(+) and CD8(+) OVA-specific TCR-transgenic naive T cells. Thus, the in vitro generation of murine pDCs may serve as a useful tool to further investigate pDC biology as well as the potential role of these cells in viral immunity and other settings.
在小鼠模型的体内以及最近在体外培养系统中，已描述了人类浆细胞样前树突状细胞（pDC）的假定对应物。在本研究中，我们报告，以Flt3配体（FL）作为唯一的外源性分化/生长因子，可产生大量骨髓来源的小鼠CD11c(+)B220(+) pDC，并且pDC的生成在体内受FL调节，因为FL缺陷小鼠脾脏pDC数量大幅减少。我们广泛分析了骨髓来源的CD11c(+)B220(+) pDC，并根据MHC II类、激活标志物和趋化因子受体表达水平描述了它们未成熟的抗原呈递细胞表型。CD11c(+)B220(+) pDC表现出与经典CD11c(+)B220(-)树突状细胞不同的、不重叠的Toll样受体表达模式，并且是较差的T细胞刺激剂。用含有特定CpG基序的寡脱氧核苷酸加CD40配体加GM-CSF刺激CD11c(+)B220(+) pDC，导致MHC II类、CD80、CD86和CD8α表达水平增加，趋化因子受体表达发生转变，这影响了它们的迁移，导致IFN-α和IL-12分泌，并获得了对CD4(+)和CD8(+) OVA特异性TCR转基因幼稚T细胞的启动能力。因此，小鼠pDC的体外生成可能作为一种有用的工具，用于进一步研究pDC生物学以及这些细胞在病毒免疫和其他环境中的潜在作用。
