Biogenesis Of The Salmonella-containing Vacuole

沙门氏菌属是兼性胞内细菌，其在空泡（SCV）内驻留和复制。SCV的生物发生由细菌决定，并涉及通过III型分泌系统易位到宿主细胞中的效应蛋白。由于肌动蛋白细胞骨架的局部重排，导致局部膜皱褶，从而发生侵袭。这一过程是由几个易位效应蛋白的协同效应诱导的。膜皱褶包含大量必须快速递送的膜。由于在SCV中仅检测到内吞标志物，因此已经假设生物合成/分泌途径不参与该过程。与蒙特利尔大学的Michel Desjardins合作，我们最近发现SCV迅速获得内质网膜，并且确实与ER相邻。因此，可能是ER对质膜皱褶的膜内容物起作用。事实上，在吞噬细胞中，ER膜可以看到与含有乳胶珠或利什曼原虫的新生吞噬体邻接。

Salmonella sp are facultative intracellular bacteria that reside and replicate within a vacuole (SCV). The biogenesis of the SCV is determined by the bacteria and involves effector proteins that are translocated into the host cell via Type III secretion systems. Invasion occurs as a result of localized membrane ruffles that are due to local rearrangement of the actin cytoskeleton. This process is induced by the co-operative effectives of several translocated effector proteins. Membrane ruffles contain large amounts of membrane that must be rapidly delivered. It has been assumed, since only endocytic markers are detected in SCVs, that the biosynthetic/secretory pathway is not involved in this process. In collaboration with Michel Desjardins at the University of Montreal, we have recently shown that the SCV rapidly acquires Endoplasmic Reticulum membranes and indeed appears contiguous with the ER. Thus it is possible that the ER is contributing membrane content to ruffles at the plasma membrane. Indeed, in phagocytic cells, ER membrane can be seen to be contiguous with nascent phagosomes containing either latex beads or Leishmania.