Complement-mediated killing of Escherichia coli by mechanical destabilization of the cell envelope

Data for research published as https://doi.org/10.1101/2023.12.10.570986 and currently under review for publication in peer reviewed journal, with data here grouped by main figures as in the submitted manuscript.Complement proteins eliminate Gram-negative bacteria in the blood via the formation of membrane attack complex (MAC) pores in the outer membrane. However, it remains unclear how outer membrane poration leads to inner membrane permeation and cell lysis. Using atomic force microscopy (AFM) on living Escherichia coli (E. coli), we probed MAC-induced changes in the cell envelope and correlated these with subsequent cell death. Initially, bacteria survived despite the formation of hundreds of MACs randomly distributed over the cell surface. This was followed by larger-scale disruption of the outer membrane, including propagating defects and fractures, and by an overall swelling and stiffening of the bacterial surface, which precede inner membrane permeation. We conclude that bacterial cell lysis is only an indirect effect of MAC formation; outer membrane poration leads to mechanical destabilization of the cell envelope, reducing its ability to contain the turgor pressure, leading to inner membrane permeation and cell death.The data stored here include AFM data of living E. coli cells exposed to complement proteins and particularly the membrane attack complex; results of data processing in the form of background subtracted images and mechanical data; and brightfield and fluorescence microscopy images that were taken complementary to AFM data on the same cells.Data files can be open with open-source AFM image processing software (e.g., Gwyddion), general image viewers (e.g., for jpeg, tiff, pdf) or any spreadsheet text readers (for e.g. txt and csv files).

本研究数据集收录了发表于https://doi.org/10.1101/2023.12.10.570986的研究成果，该成果目前正在同行评审期刊中进行审稿。数据按照提交的稿件中的主要图示进行分组。补体蛋白通过在革兰氏阴性菌的外膜形成膜攻击复合物（MAC）孔洞来消除血液中的细菌。然而，外膜穿孔如何导致内膜渗透和细胞裂解尚不明确。本研究利用原子力显微镜（AFM）对活性的大肠杆菌（E. coli）进行检测，探究了MAC诱导的细胞外膜变化，并将其与后续的细胞死亡相关联。最初，尽管在细胞表面形成了数百个MAC，但细菌仍存活。随后，外膜发生了更大规模的破坏，包括传播缺陷和断裂，以及细菌表面的整体肿胀和硬化，这些均预示着内膜渗透的发生。我们得出结论，细菌细胞裂解是MAC形成的一个间接效应；外膜穿孔导致细胞外膜机械稳定性下降，降低其维持膨压的能力，进而引起内膜渗透和细胞死亡。此处存储的数据包括暴露于补体蛋白和特别是膜攻击复合物的活性的大肠杆菌细胞的AFM数据；数据处理的成果，以背景减除图像和机械数据的形式呈现；以及与AFM数据相对应的同一细胞的明场和荧光显微镜图像。数据文件可以使用开源的AFM图像处理软件（例如Gwyddion）、通用图像查看器（例如jpeg、tiff、pdf查看器）或任何电子表格文本阅读器（例如txt和csv文件阅读器）打开。