High-Content Imaging Reveals Expansion of the Endosomal Compartment during Coxiella burnetii Parasitophorous Vacuole Maturation.
High-Content Imaging Reveals Expansion of the Endosomal Compartment during Coxiella burnetii Parasitophorous Vacuole Maturation.
复制标题
高内涵成像揭示伯内氏立克次体寄生液泡成熟过程中内体室的扩张。
DOI：
10.3389/fcimb.2017.00048
复制
发表时间：
2017
影响因子：
5.7
通讯作者：
Heinzen RA
中科院分区：
文献类型：
--
作者：
Larson CL;Heinzen RA
贝氏柯克斯体（Coxiellaburnetii）是一种专性胞内致病菌，是引起人类Q热的病原体。病原菌在一个类似宿主吞噬溶酶体的大的寄生虫空泡（PV）内复制是致病所必需的。PV生物发生是一个病原体驱动的过程，需要参与几个宿主细胞囊泡运输途径，以获得液泡成分。本研究的目的是确定是否由C.贝氏菌调节内溶酶体通量以潜在地有益于PV形成。HeLa细胞感染C.将贝氏体或未感染的贝氏体与荧光转铁蛋白（Tf）孵育0-30分钟，并通过高含量成像定量细胞内化的Tf的量。在3和5天，但不是1天感染后，最大量的荧光Tf内化的感染细胞显着大于未感染的细胞。感染和未感染细胞的Tf摄取和回收率是相同的;然而，在没有标记Tf的情况下，回收30分钟后，残留Tf持续存在于邻近大PV的EEA.1阳性隔室中。平均而言，C. Burnetii感染的细胞比未感染的细胞含有显著更多的CD 63阳性内体。相反，沙眼衣原体产生的含有大空泡的细胞表现出增加的Tf内化率，而不增加CD 63表达。我们的结果表明C.贝氏体感染扩展了内体系统以增加内吞物质的能力。此外，本研究还证明了高含量成像用于测量细胞内病原体感染的细胞反应的能力。
Coxiella burnetii is an obligate intracellular pathogen and the causative agent of human Q fever. Replication of the bacterium within a large parasitophorous vacuole (PV) resembling a host phagolysosome is required for pathogenesis. PV biogenesis is a pathogen driven process that requires engagement of several host cell vesicular trafficking pathways to acquire vacuole components. The goal of this study was to determine if infection by C. burnetii modulates endolysosomal flux to potentially benefit PV formation. HeLa cells, infected with C. burnetii or left uninfected, were incubated with fluorescent transferrin (Tf) for 0–30 min, and the amount of Tf internalized by cells quantitated by high-content imaging. At 3 and 5 days, but not 1 day post-infection, the maximal amounts of fluorescent Tf internalized by infected cells were significantly greater than uninfected cells. The rates of Tf uptake and recycling were the same for infected and uninfected cells; however, residual Tf persisted in EEA.1 positive compartments adjacent to large PV after 30 min of recycling in the absence of labeled Tf. On average, C. burnetii-infected cells contained significantly more CD63-positive endosomes than uninfected cells. In contrast, cells containing large vacuoles generated by Chlamydia trachomatis exhibited increased rates of Tf internalization without increased CD63 expression. Our results suggest that C. burnetii infection expands the endosomal system to increase capacity for endocytic material. Furthermore, this study demonstrates the power of high-content imaging for measurement of cellular responses to infection by intracellular pathogens.