Circulating blood cells function as a surveillance system for damaged tissue in Drosophila larvae
Circulating blood cells function as a surveillance system for damaged tissue in Drosophila larvae
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DOI：
10.1073/pnas.0709951105
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发表时间：
2008-07-22
影响因子：
11.1
通讯作者：
Galko, Michael J.
中科院分区：
文献类型：
--
作者：
Babcock, Daniel T.;Brock, Amanda R.;Galko, Michael J.
昆虫有一个开放的循环系统，其中心脏将血液（血淋巴）泵入体腔，在那里它直接沐浴内部器官和表皮。血液中含有游离的和组织结合的免疫细胞，它们在炎症反应中发挥作用。在这里，我们使用荧光标记的血细胞（血细胞）转基因果蝇幼虫的实时成像，以调查幼虫血细胞的循环动力学及其对组织损伤的反应。我们发现，在正常条件下，游离细胞快速循环，而组织结合的细胞是固着的。在表皮创伤后，创伤部位周围的组织结合细胞保持无柄和无反应，而循环细胞通过粘附捕获迅速募集到损伤部位。捕获后，这些细胞分布在伤口上，表现出吞噬活性，随后通过愈合的表皮释放回循环中。结果表明，循环细胞的功能作为一个监视系统，监测幼虫组织的损害，和粘合剂捕获，一个重要的机制，招聘循环细胞在脊椎动物的炎症部位，是共享的昆虫和脊椎动物，尽管他们的循环系统的架构有很大的不同。
Insects have an open circulatory system in which the heart pumps blood (hemolymph) into the body cavity, where it directly bathes the internal organs and epidermis. The blood contains free and tissue-bound immune cells that function in the inflammatory response. Here, we use live imaging of transgenic Drosophila larvae with fluorescently labeled blood cells (hemocytes) to investigate the circulatory dynamics of larval blood cells and their response to tissue injury. We find that, under normal conditions, the free cells rapidly circulate, whereas the tissue-bound cells are sessile. After epidermal wounding, tissue-bound cells around the wound site remain sessile and unresponsive, whereas circulating cells are rapidly recruited to the site of damage by adhesive capture. After capture, these cells distribute across the wound, appear phagocytically active, and are subsequently released back into circulation by the healing epidermis. The results demonstrate that circulating cells function as a surveillance system that monitors larval tissues for damage, and that adhesive capture, an important mechanism of recruitment of circulating cells to inflammatory sites in vertebrates, is shared by insects and vertebrates despite the vastly different architectures of their circulatory systems.