Maturation of the Coxiella burnetii parasitophorous vacuole requires bacterial protein synthesis but not replication
Maturation of the Coxiella burnetii parasitophorous vacuole requires bacterial protein synthesis but not replication
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DOI：
10.1046/j.1462-5822.2003.00293.x
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发表时间：
2003-07-01
影响因子：
3.4
通讯作者：
Heinzen, RA
中科院分区：
文献类型：
--
作者：
Howe, D;Melnicáková, J;Heinzen, RA
本研究探讨了伯内特柯克斯体（一种专性细胞内细菌）的溶酶体样、大而宽敞的寄生液泡（PV）的成熟和融合性是否需要蛋白质合成和复制。在感染复数为 10 并用抑菌浓度的萘啶酸或羧苄青霉素（分别抑制 DNA 和细胞壁生物合成的抗菌剂）处理的 Vero 细胞中，通过相差显微镜观察到具有多个非复制性伯氏念珠菌的大而宽敞的 PV。相反，在用抑菌浓度的蛋白质合成抑制剂氯霉素处理的细胞中没有观察到大而宽敞的PV。相反，单个细胞的荧光显微镜显示多个酸性PV含有由LAMP-1阳性液泡膜紧密结合的单个生物体。去除药物后，这些液泡同型融合形成大而宽敞的 PV。氯霉素还抑制乳胶珠向大而宽敞的PV的运输，并导致成熟的PV塌陷。总的来说，这些结果表明，新生的伯内特伯内氏菌 PV 和乳胶珠吞噬体之间的融合，以及大而宽敞的复制性 PV 的形成和维持，都需要伯内特伯内特伯内特伯内氏菌蛋白质合成，但不是复制。然而，新生PV通过内吞途径最终获得溶酶体标记的情况似乎与柯克斯体蛋白合成无关。
This study examined whether protein synthesis and replication are required for maturation and fusogenicity of the lysosomal-like, large and spacious parasitophorous vacuole (PV) of Coxiella burnetii, an obligate intracellular bacterium. Large and spacious PV with multiple non-replicating C. burnetii were observed by phase microscopy in Vero cells infected at a multiplicity of infection of ten and treated with a bacteriostatic concentration of nalidixic acid or carbenicillin, antimicrobics that inhibit DNA and cell wall biosynthesis respectively. Conversely, large and spacious PV were not observed in cells treated with a bacteriostatic concentration of the protein synthesis inhibitor chloramphenicol. Rather, fluorescence microscopy of individual cells revealed multiple, acidic PV harbouring a single organism tightly bounded by a LAMP-1 positive vacuolar membrane. These vacuoles homotypically fused to form a large and spacious PV upon removal of the drug. Chloramphenicol also inhibited trafficking of latex beads to large and spacious PV and caused mature PV to collapse. Collectively, these results demonstrate that C. burnetii protein synthesis, but not replication, is required for fusion between nascent C. burnetii PV and latex bead phagosomes, and also for formation and maintenance of large and spacious, replicative PV. However, transit of nascent PV through the endocytic pathway to ultimately acquire lysosomal markers appears to occur irrespective of Coxiella protein synthesis.