Live Imaging of Disseminated Candidiasis in Zebrafish Reveals Role of Phagocyte Oxidase in Limiting Filamentous Growth
Live Imaging of Disseminated Candidiasis in Zebrafish Reveals Role of Phagocyte Oxidase in Limiting Filamentous Growth
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DOI：
10.1128/ec.05005-11
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发表时间：
2011-07-01
期刊：
影响因子：
--
通讯作者：
Wheeler, Robert T.
中科院分区：
文献类型：
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作者：
Brothers, Kimberly M.;Newman, Zachary R.;Wheeler, Robert T.
白色念珠菌是一种重要的真菌病原体，在人类感染过程中以酵母和菌丝两种形式生长。虽然念珠菌可引起皮肤和粘膜疾病，但全身感染引起的死亡率最高。血吸虫病主要发生在免疫功能低下的患者中，对他们来说，先天免疫系统在免疫中起着至关重要的作用。我们已经开发了一种新的透明脊椎动物模型的念珠菌血症探测的分子性质的念珠菌先天免疫系统的相互作用在一个完整的主机。我们的斑马鱼感染模型导致一种致命的播散性疾病，该疾病与哺乳动物中的播散性念珠菌病具有重要特征，包括双态真菌生长、对菌丝生长的毒力依赖以及对吞噬细胞NADPH氧化酶的免疫依赖。荧光标记的免疫细胞和真菌的双重成像显示，被吞噬的酵母细胞可以保持活力，甚至在巨噬细胞内分裂而不发芽。同样，虽然我们观察到中性粒细胞内的酵母细胞明显被杀死，但这些先天免疫细胞内的大多数酵母细胞是活的。利用这个模型，我们结合活体成像和基因敲除，首次显示NADPH氧化酶是调节C。白念珠菌体内培养。透明和易于操作的斑马鱼幼虫模型有望提供一个独特的工具，解剖吞噬细胞NADPH氧化酶介导的限制丝状体生长在体内的分子基础。
Candida albicans is a human commensal and a clinically important fungal pathogen that grows in both yeast and hyphal forms during human infection. Although Candida can cause cutaneous and mucosal disease, systemic infections cause the greatest mortality in hospitals. Candidemia occurs primarily in immunocompromised patients, for whom the innate immune system plays a paramount role in immunity. We have developed a novel transparent vertebrate model of candidemia to probe the molecular nature of Candida-innate immune system interactions in an intact host. Our zebrafish infection model results in a lethal disseminated disease that shares important traits with disseminated candidiasis in mammals, including dimorphic fungal growth, dependence on hyphal growth for virulence, and dependence on the phagocyte NADPH oxidase for immunity. Dual imaging of fluorescently marked immune cells and fungi revealed that phagocytosed yeast cells can remain viable and even divide within macrophages without germinating. Similarly, although we observed apparently killed yeast cells within neutrophils, most yeast cells within these innate immune cells were viable. Exploiting this model, we combined intravital imaging with gene knockdown to show for the first time that NADPH oxidase is required for regulation of C. albicans filamentation in vivo. The transparent and easily manipulated larval zebrafish model promises to provide a unique tool for dissecting the molecular basis of phagocyte NADPH oxidase-mediated limitation of filamentous growth in vivo.