title: Enteropathogenic Escherichia coli type III effectors EspG and EspG2 alter epithelial paracellular permeability.
abstract: Enteropathogenic Escherichia coli (EPEC) delivers a subset of effectors into host cells via a type III secretion system. Here we show that the type III effector EspG and its homologue EspG2 alter epithelial paracellular permeability. When MDCK cells were infected with wild-type (WT) EPEC, RhoA was activated, and this event was dependent on the delivery of either EspG or EspG2 into host cells. In contrast, a loss of transepithelial electrical resistance and ZO-1 disruption were induced by infection with an espG/espG2 double-knockout mutant, as was the case with the WT EPEC, indicating that EspG/EspG2 is not involved in the disruption of tight junctions during EPEC infection. Although EspG- and EspG2-expressing MDCK cells exhibited normal overall morphology and maintained fully assembled tight junctions, the paracellular permeability to 4-kDa dextran, but not the paracellular permeability to 500-kDa dextran, was greatly increased. This report reveals for the first time that a pathogen can regulate the size-selective paracellular permeability of epithelial cells in order to elicit a disease process.
authors.affiliation: Laboratory of Bacterial Infection, Kitasato Institute for Life Sciences, Kitasato University, Minato-ku, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsuzawa
authors.forename: Asaomi
authors.initials: A
authors.lastname: Kuwae
authors.forename: Akio
authors.initials: A
authors.lastname: Abe
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology*; D004926:Escherichia coli / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D010539:Permeability; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism / Q000382:microbiology; D062826:Zonula Occludens-1 Protein; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; C429282:EspG protein, E coli; C505458:EspG2 protein, E coli; D008565:Membrane Proteins; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein; D020742:rhoA GTP-Binding Protein