D'Amico Angela, Wu Li
The Walter and Eliza Hall Institute of Medical Research, 1G, Royal Parade, Parkville, Victoria 3050, Australia.
J Exp Med. 2003 Jul 21;198(2):293-303. doi: 10.1084/jem.20030107.
Flt3 ligand (Flt3L) is a growth factor for hemopoietic progenitors and can promote the expansion of both conventional dendritic cells (DCs) and plasmacytoid predendritic cells (p-preDCs). The cells responding to Flt3L treatment and the precursors for the DCs and p-preDCs had not been fully characterized. We examined different mouse bone marrow (BM) hemopoietic precursor populations for the surface expression of Flt3 and tested them for early DC and p-preDC precursor activity. Most DC precursor activity, other than that given by multipotent hemopoietic stem cells, was within the downstream precursors expressing Flt3. The majority of mouse BM common lymphoid precursors expressed high levels of Flt3 and these were the most efficient precursors of both DCs and p-preDCs. In contrast, only a small proportion of the common myeloid precursors (CMPs) expressed Flt3, but the precursor activity for both DCs and p-preDCs was within this minor Flt3+ CMP fraction. The granulocyte and macrophage precursors and pro-B cells did not express Flt3 and had no DC or p-preDC precursor activity. These findings demonstrate that the early precursors for all DC subtypes are within the BM Flt3+ precursor populations, regardless of their lymphoid or myeloid lineage orientation.
Flt3配体（Flt3L）是造血祖细胞的生长因子，可促进常规树突状细胞（DC）和浆细胞样前树突状细胞（p-preDC）的扩增。对Flt3L治疗有反应的细胞以及DC和p-preDC的前体尚未得到充分表征。我们检查了不同小鼠骨髓（BM）造血前体群体的Flt3表面表达，并测试了它们的早期DC和p-preDC前体活性。除多能造血干细胞外，大多数DC前体活性存在于表达Flt3的下游前体中。大多数小鼠BM常见淋巴前体表达高水平的Flt3，这些是DC和p-preDC最有效的前体。相比之下，只有一小部分常见髓系前体（CMP）表达Flt3，但DC和p-preDC的前体活性都在这个较小的Flt3 + CMP部分中。粒细胞和巨噬细胞前体以及前B细胞不表达Flt3且没有DC或p-preDC前体活性。这些发现表明，所有DC亚型的早期前体都在BM Flt3 +前体群体中，无论它们的淋巴或髓系谱系方向如何。
