Essential role of the VirB machinery in the maturation of the Brucella abortus-containing vacuole
Essential role of the VirB machinery in the maturation of the Brucella abortus-containing vacuole
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DOI：
10.1046/j.1462-5822.2001.00102.x
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发表时间：
2001-03-01
影响因子：
3.4
通讯作者：
Ugalde, RA
中科院分区：
文献类型：
--
作者：
Comerci, DJ;Martínez-Lorenzo, MJ;Ugalde, RA
在上皮细胞中，细胞内病原体流产布鲁氏菌从内吞途径逃逸，利用宿主细胞的自噬机制，并在内质网中建立独特的复制小生境。这些过程背后的分子机制仍然知之甚少。最近，一个B。由virB操纵子编码的流产IV型相关分泌系统已被描述为参与细菌的细胞内运输。在这项研究中，我们分析了B，流产病毒virB 10突变株的细胞内途径，我们证明，一个功能性的virB操纵子是必不可少的生物合成的布鲁氏菌含有空泡，极性突变阻止virB 10和下游序列的转录不允许布鲁氏菌绕过内吞途径。因此，含有极性mu的空泡与溶酶体融合，细菌在其中经历降解过程。相比之下，virB10非极性突变体能够避免与内吞途径的相互作用，但与野生型布鲁氏菌不同，无法到达内质网以建立其细胞内复制小生境，并且似乎被回收到细胞表面。基于在这项工作中描述的两个特定的表型，提出了一个模型的成熟的布鲁氏菌含有液泡。
In epithelial cells, the intracellular pathogen Brucella abortus escapes from the endocytic pathway, exploits the autophagic machinery of the host cell and establishes a unique replication niche in the endoplasmic reticulum. The molecular mechanisms underlying these processes are still poorly understood. Recently, a B. abortus type IV-related secretion system encoded by the virB operon has been described as being involved in the intracellular trafficking of the bacteria. In this study, we have analysed the intracellular pathway of B, abortus virB10 mutant strains by confocal microscopy, We demonstrate that a functional virB operon is essential for the biogenesis of the Brucella-containing vacuole, Polar mutation preventing the transcription of virB10 and downstream sequences did not allow Brucella to bypass the endocytic pathway. Consequently, polar mutant-containing vacuoles fused with lysosomes in which bacteria underwent a degradation process. In contrast, virB10 non-polar mutants were capable of avoiding interactions with the endocytic pathway but, diverging to wild-type Brucella, were unable to reach the endoplasmic reticulum to establish their intracellular replication niche and seemed to be recycled to the cell surface. Based on the two particular phenotypes described in this work, a model of maturation of the Brucella-containing vacuole is proposed.