Rotation of Vibrio fischeri Flagella Produces Outer Membrane Vesicles That Induce Host Development
Rotation of Vibrio fischeri Flagella Produces Outer Membrane Vesicles That Induce Host Development
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DOI：
10.1128/jb.00101-16
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发表时间：
2016-08-01
影响因子：
3.2
通讯作者：
Ruby, Edward
中科院分区：
文献类型：
--
作者：
Aschtgen, Marie-Stephanie;Lynch, Jonathan B.;Ruby, Edward
使用鱿鱼弧菌协会，我们的目的是通过它的机制，费氏弧菌细胞信号的共生发光器官的形态发生的特征。共生体释放两种细胞包膜分子，肽聚糖（PG）和脂多糖（LPS），在轻器官定植的12小时内，协同作用，触发正常组织发育。最近的研究表明，费氏弧菌产生的外膜囊泡（OMV）足以诱导PG依赖性形态发生;然而，这些细菌释放OMV的机制尚未描述。与几种有益菌和致病菌一样，费氏弧菌细胞也有极鞭毛，被外膜的延伸部分包围，其功能尚不清楚。在这里，我们提出的证据表明，沿着公认的现象，从细胞的表面起泡，旋转的这套鞭毛也导致OMV的释放。此外，我们表明，大多数的发展诱导LPS与这些OMV和外膜蛋白OmpU的存在下，但不是这些OMV上的LPS O抗原是重要的，在触发正常的主机发展。这些结果也提出了一个可能的新机制的LPS释放的病原体与鞘鞭毛的见解。IMPORTANCEDetermining的功能（S）的鞘鞭毛在细菌中一直具有挑战性，因为没有已知的突变结果，只有在这种外膜衍生的外壳的损失。然而，在宿主相关属如弧菌属、螺杆菌属和布鲁氏菌属中存在有鞘鞭毛导致了几种拟议的功能，包括鞭毛的物理保护和其免疫原性鞭毛蛋白的掩蔽。使用乌贼弧菌轻器官共生，我们证明了另一个作用，即V. fischeri细胞需要旋转鞭毛诱导表面上皮细胞内的凋亡细胞死亡，这是器官发育中的正常步骤。此外，我们提出的证据表明，这种旋转释放的外膜囊泡的形式的骨化触发脂多糖。这种释放也可能由病原体发生，但对宿主有不同的结果。
Using the squid-vibrio association, we aimed to characterize the mechanism through which Vibrio fischeri cells signal morphogenesis of the symbiotic light-emitting organ. The symbiont releases two cell envelope molecules, peptidoglycan (PG) and lipopolysaccharide (LPS) that, within 12 h of light organ colonization, act in synergy to trigger normal tissue development. Recent work has shown that outer membrane vesicles (OMVs) produced by V. fischeri are sufficient to induce PG-dependent morphogenesis; however, the mechanism(s) of OMV release by these bacteria has not been described. Like several genera of both beneficial and pathogenic bacteria, V. fischeri cells elaborate polar flagella that are enclosed by an extension of the outer membrane, whose function remains unclear. Here, we present evidence that along with the well-recognized phenomenon of blebbing from the cell's surface, rotation of this sheathed flagellum also results in the release of OMVs. In addition, we demonstrate that most of the development-inducing LPS is associated with these OMVs and that the presence of the outer membrane protein OmpU but not the LPS O antigen on these OMVs is important in triggering normal host development. These results also present insights into a possible new mechanism of LPS release by pathogens with sheathed flagella.IMPORTANCEDetermining the function(s) of sheathed flagella in bacteria has been challenging, because no known mutation results only in the loss of this outer membrane-derived casing. Nevertheless, the presence of a sheathed flagellum in such host-associated genera as Vibrio, Helicobacter, and Brucella has led to several proposed functions, including physical protection of the flagella and masking of their immunogenic flagellins. Using the squid-vibrio light organ symbiosis, we demonstrate another role, that of V. fischeri cells require rotating flagella to induce apoptotic cell death within surface epithelium, which is a normal step in the organ's development. Further, we present evidence that this rotation releases apoptosis-triggering lipopolysaccharide in the form of outer membrane vesicles. Such release may also occur by pathogens but with different outcomes for the host.