Extracellular motility and cell-to-cell transmission of enterohemorrhagic E. coli is driven by EspFU-mediated actin assembly

PLoS Pathogens

Kenneth G. Campellone¹  Katrina B. Velle¹ 

[1] Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America

关键词: Pathogen motility;    Actins;    Enterohaemorrhagic Escherichia coli;    Cell motility;    Host cells;    Cell staining;    Gastrointestinal tract;    Epithelial cells;   

DOI  :  10.1371/journal.ppat.1006501

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) are closely-related pathogens that attach tightly to intestinal epithelial cells, efface microvilli, and promote cytoskeletal rearrangements into protrusions called actin pedestals. To trigger pedestal formation, EPEC employs the tyrosine phosphorylated transmembrane receptor Tir, while EHEC relies on the multivalent scaffolding protein EspFU. The ability to generate these structures correlates with bacterial colonization in several animal models, but the precise function of pedestals in infection remains unclear. To address this uncertainty, we characterized the colonization properties of EPEC and EHEC during infection of polarized epithelial cells. We found that EPEC and EHEC both formed distinct bacterial communities, or “macrocolonies,” that encompassed multiple host cells. Tir and EspFU, as well as the host Arp2/3 complex, were all critical for the expansion of macrocolonies over time. Unexpectedly, EspFU accelerated the formation of larger macrocolonies compared to EPEC Tir, as EspFU-mediated actin assembly drove faster bacterial motility to cell junctions, where bacteria formed a secondary pedestal on a neighboring cell and divided, allowing one of the daughters to disengage and infect the second cell. Collectively, these data reveal that EspFU enhances epithelial colonization by increasing actin-based motility and promoting an efficient method of cell-to-cell transmission.

【 授权许可】

CC BY