School of Global Animal Health, Washington State University, Pullman, United States.
Elife. 2019 Apr 24;8:e45252. doi: 10.7554/eLife.45252.
Previously, we found that phagocytic cells ingest bacteria directly from the cytosol of infected cells without killing the initially infected cell (Steele et al., 2016). Here, we explored the events immediately following bacterial transfer. bacteria acquired from infected cells were found within double-membrane vesicles partially composed from the donor cell plasma membrane. As with phagosomal escape, the Type VI Secretion System (T6SS) was required for vacuole escape. We constructed a T6SS inducible strain and established conditions where this strain is trapped in vacuoles of cells infected through bacterial transfer. Using this strain we identified bacterial transfer events in the lungs of infected mice, demonstrating that this process occurs in infected animals. These data and electron microscopy analysis of the transfer event revealed that macrophages acquire cytoplasm and membrane components of other cells through a process that is distinct from, but related to phagocytosis.
此前，我们发现吞噬细胞可以在不杀死最初感染细胞的情况下，直接从感染细胞的细胞质中摄取细菌（Steele 等人，2016 年）。在这里，我们探索了细菌转移后立即发生的事件。从感染细胞中获得的细菌被发现存在于双层囊泡中，这些囊泡部分由供体细胞的质膜组成。与吞噬体逃逸一样，VI 型分泌系统（T6SS）对于液泡逃逸是必需的。我们构建了一个可诱导 T6SS 的菌株，并建立了条件，使该菌株在通过细菌转移感染的细胞的液泡中被捕获。使用这种菌株，我们在感染小鼠的肺部中鉴定到了细菌转移事件，证明了这一过程发生在感染动物体内。这些数据以及对转移事件的电子显微镜分析表明，巨噬细胞通过一种与吞噬作用不同但相关的过程获取其他细胞的细胞质和膜成分。
