Le Guyader Dorothée, Redd Michael J, Colucci-Guyon Emma, Murayama Emi, Kissa Karima, Briolat Valérie, Mordelet Elodie, Zapata Agustin, Shinomiya Hiroto, Herbomel Philippe
Unité Macrophages et Développement de l'Immunité, Centre National de la Recherche Scientifique-Unité de Recherche Associée 2578, Institut Pasteur, Paris, France.
Blood. 2008 Jan 1;111(1):132-41. doi: 10.1182/blood-2007-06-095398. Epub 2007 Sep 17.
The first leukocytes that arise in the development of vertebrate embryos are the primitive macrophages, which differentiate in the yolk sac and then quickly invade embryonic tissues. These macrophages have been considered to constitute a separate lineage, giving rise to no other cell type. Using an in vivo photoactivatable cell tracer in the transparent zebrafish (Danio rerio) embryo, we demonstrated that this lineage also gave rise to an equal or higher number of neutrophilic granulocytes. We were surprised to find that the differentiation of these primitive neutrophils occurs only after primitive myeloid progenitors have dispersed in the tissues. By 2 days after fertilization, these neutrophils have become the major leukocyte type found wandering in the epidermis and mesenchyme. Like the primitive macrophages, all primitive and larval neutrophils express PU.1 and L-plastin and they are highly attracted to local infections, yet only a small fraction of them phagocytose microbes, and to a much lesser extent per cell than the macrophages. They are also attracted to variously stressed or malformed tissues, suggesting a wider role than antimicrobial defense.
在脊椎动物胚胎发育过程中出现的首批白细胞是原始巨噬细胞，它们在卵黄囊中分化，然后迅速侵入胚胎组织。这些巨噬细胞被认为构成一个独立的谱系，不会产生其他细胞类型。我们在透明的斑马鱼胚胎中使用体内光激活细胞示踪剂，证明这个谱系还产生了数量相等或更多的嗜中性粒细胞。我们惊讶地发现，这些原始嗜中性粒细胞的分化仅在原始髓系祖细胞分散到组织中之后才发生。受精后2天，这些嗜中性粒细胞已成为在表皮和间充质中游走的主要白细胞类型。与原始巨噬细胞一样，所有原始和幼体嗜中性粒细胞都表达PU.1和L-原肌球蛋白，它们对局部感染具有高度吸引力，但只有一小部分会吞噬微生物，而且每个细胞吞噬微生物的程度比巨噬细胞小得多。它们也被各种应激或畸形组织所吸引，这表明其作用比抗菌防御更广泛。
