Developmental stage oxidoreductive states of Chlamydia and infected host cells.
Developmental stage oxidoreductive states of Chlamydia and infected host cells.
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DOI：
10.1128/mbio.01924-14
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发表时间：
2014-10-28
期刊：
影响因子：
6.4
通讯作者：
Stephens RS
中科院分区：
文献类型：
--
作者：
Wang X;Schwarzer C;Hybiske K;Machen TE;Stephens RS
衣原体属的一个定义特征。是它们的发育周期，其特征在于富含半胱氨酸的外膜蛋白之间的半胱氨酸键的外膜转化。宿主细胞室的还原-氧化状态进行了监测，在发育周期中使用活荧光显微镜。细胞器的氧化还原状态进行了研究，使用氧化还原敏感的绿色荧光蛋白（roGFP 1）表达的CF 15上皮细胞和针对细胞质，线粒体，内质网（ER）。衣原体和夹杂物的氧化还原特性进行了监测，使用由沙眼衣原体转化后表达的roGFP。尽管衣原体感染引起了巨大的形态学变化，但胞质（胞浆）、线粒体（线粒体）和内质网（内质网）的氧化还原电位及其特有的氧化还原调节能力在细胞死亡前保持不变，此时胞浆和线粒体变得更加氧化，而内质网变得更加还原。在沙眼衣原体中的roGFP生物传感器的转化和表达之后，在整个发育周期中测量腔细胞质的氧化还原状态。周质和外膜的氧化还原状态进行了评估的半胱氨酸交联的水平，富含半胱氨酸的包膜蛋白。在这两种情况下，披衣细胞在发育周期的早期高度减少，并在发育周期的晚期被氧化。后期发育阶段的氧化还原酶/异构酶，DsbJ的生产，可能发挥关键作用的氧化还原发育阶段的特定过程的调节。传染性衣原体生物体具有高度氧化和半胱氨酸交联的膜蛋白，当在其宿主细胞外时赋予环境稳定性。一旦这些生物体感染新的宿主细胞，蛋白质就会减少，并在活跃生长阶段保持减少。这些蛋白质在其生长周期结束时被氧化，其中产生感染性生物并释放到环境中。衣原体如何介导和调节其发病机制中的这一关键步骤尚不清楚。使用专门针对感染的宿主细胞内的不同隔室和衣原体生物体本身的生物传感器，在感染过程中测量这些隔室的氧化还原状态。我们发现，宿主细胞的氧化还原状态不会因感染沙眼衣原体而改变，而衣原体生物体的状态在感染期间保持还原，直到发育后期，其中生物体的细胞质和周质被氧化，并且它们获得环境抗性和感染性。
A defining characteristic of Chlamydia spp. is their developmental cycle characterized by outer membrane transformations of cysteine bonds among cysteine-rich outer membrane proteins. The reduction-oxidation states of host cell compartments were monitored during the developmental cycle using live fluorescence microscopy. Organelle redox states were studied using redox-sensitive green fluorescent protein (roGFP1) expressed in CF15 epithelial cells and targeted to the cytosol, mitochondria, and endoplasmic reticulum (ER). The redox properties of chlamydiae and the inclusion were monitored using roGFP expressed by Chlamydia trachomatis following transformation. Despite the large morphological changes associated with chlamydial infection, redox potentials of the cytosol (Ψcyto [average, −320 mV]), mitochondria (Ψmito [average, −345 mV]), and the ER (ΨER [average, −258 mV]) and their characteristic redox regulatory abilities remained unchanged until the cells died, at which point Ψcyto and Ψmito became more oxidized and ΨER became more reduced. The redox status of the chamydial cytoplasm was measured following transformation and expression of the roGFP biosensor in C. trachomatis throughout the developmental cycle. The periplasmic and outer membrane redox states were assessed by the level of cysteine cross-linking of cysteine-rich envelope proteins. In both cases, the chlamydiae were highly reduced early in the developmental cycle and became oxidized late in the developmental cycle. The production of a late-developmental-stage oxidoreductase/isomerase, DsbJ, may play a key role in the regulation of the oxidoreductive developmental-stage-specific process. Infectious Chlamydia organisms have highly oxidized and cysteine cross-linked membrane proteins that confer environmental stability when outside their host cells. Once these organisms infect a new host cell, the proteins become reduced and remain reduced during the active growth stage. These proteins become oxidized at the end of their growth cycle, wherein infectious organisms are produced and released to the environment. How chlamydiae mediate and regulate this key step in their pathogenesis is unknown. Using biosensors specifically targeted to different compartments within the infected host cell and for the chlamydial organisms themselves, the oxidoreductive states of these compartments were measured during the course of infection. We found that the host cell redox states are not changed by infection with C. trachomatis, whereas the state of the chlamydial organisms remains reduced during infection until the late developmental stages, wherein the organisms’ cytosol and periplasm become oxidized and they acquire environmental resistance and infectivity.