PDF(Pubmed)
Abstract：
Microsporidia are an early-diverging group of fungal pathogens with a wide host range. Several microsporidian species cause opportunistic infections in humans that can be fatal. As obligate intracellular parasites with highly reduced genomes, microsporidia are dependent on host metabolites for successful replication and development. Our knowledge of microsporidian intracellular development remains rudimentary, and our understanding of the intracellular niche occupied by microsporidia has relied on 2D TEM images and light microscopy. Here, we use serial block-face scanning electron microscopy (SBF-SEM) to capture 3D snapshots of the human-infecting species, Encephalitozoon intestinalis, within host cells. We track E. intestinalis development through its life cycle, which allows us to propose a model for how its infection organelle, the polar tube, is assembled de novo in developing spores. 3D reconstructions of parasite-infected cells provide insights into the physical interactions between host cell organelles and parasitophorous vacuoles, which contain the developing parasites. The host cell mitochondrial network is substantially remodeled during E. intestinalis infection, leading to mitochondrial fragmentation. SBF-SEM analysis shows changes in mitochondrial morphology in infected cells, and live-cell imaging provides insights into mitochondrial dynamics during infection. Our data provide insights into parasite development, polar tube assembly, and microsporidia-induced host mitochondria remodeling.
摘要：
微孢子虫是一种早期分化的真菌病原体，宿主范围广。几种微孢子虫物种在人类中引起机会性感染，可能是致命的。作为基因组高度减少的专性细胞内寄生虫，微孢子虫依赖于宿主代谢产物进行成功的复制和发育。我们对微孢子虫细胞内发育的了解还很初步,我们对微孢子虫占据的细胞内生态位的理解依赖于2DTEM图像和光学显微镜。这里,我们使用串行块面扫描电子显微镜（SBF-SEM）捕获人类感染物种的3D快照，头孢菌素肠肌，在宿主细胞内。我们通过它的生命周期跟踪肠球菌的发育，这使我们能够提出一个模型，极管，在发育中的孢子中从头组装。寄生虫感染细胞的3D重建提供了对宿主细胞器和寄生虫空泡之间物理相互作用的见解。其中含有正在发育的寄生虫。宿主细胞线粒体网络在大肠埃希氏菌感染期间被显著重塑,导致线粒体碎片化。SBF-SEM分析显示感染细胞中线粒体形态的变化，活细胞成像提供了对感染过程中线粒体动力学的见解。我们的数据提供了有关寄生虫发育的见解，极管组件,和微孢子虫诱导的宿主线粒体重塑。
