Pseudomonas aeruginosa vesicles associate with and are internalized by human lung epithelial cells.
Abstract
BACKGROUND: Pseudomonas aeruginosa is the major pathogen associated with chronic and
ultimately fatal lung infections in patients with cystic fibrosis (CF). To investigate
how P. aeruginosa-derived vesicles may contribute to lung disease, we explored their
ability to associate with human lung cells. RESULTS: Purified vesicles associated
with lung cells and were internalized in a time- and dose-dependent manner. Vesicles
from a CF isolate exhibited a 3- to 4-fold greater association with lung cells than
vesicles from the lab strain PAO1. Vesicle internalization was temperature-dependent
and was inhibited by hypertonic sucrose and cyclodextrins. Surface-bound vesicles
rarely colocalized with clathrin. Internalized vesicles colocalized with the endoplasmic
reticulum (ER) marker, TRAPalpha, as well as with ER-localized pools of cholera toxin
and transferrin. CF isolates of P. aeruginosa abundantly secrete PaAP (PA2939), an
aminopeptidase that associates with the surface of vesicles. Vesicles from a PaAP
knockout strain exhibited a 40% decrease in cell association. Likewise, vesicles from
PAO1 overexpressing PaAP displayed a significant increase in cell association. CONCLUSION:
These data reveal that PaAP promotes the association of vesicles with lung cells.
Taken together, these results suggest that P. aeruginosa vesicles can interact with
and be internalized by lung epithelial cells and contribute to the inflammatory response
during infection.
Type
Journal articleSubject
AminopeptidasesCell Line
Cystic Fibrosis
Endoplasmic Reticulum
Epithelial Cells
Humans
Lung
Lung Diseases
Pseudomonas Infections
Temperature
Transport Vesicles
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https://hdl.handle.net/10161/10660Published Version (Please cite this version)
10.1186/1471-2180-9-26Publication Info
Bauman, Susanne J; & Kuehn, Meta J (2009). Pseudomonas aeruginosa vesicles associate with and are internalized by human lung
epithelial cells. BMC Microbiol, 9. pp. 26. 10.1186/1471-2180-9-26. Retrieved from https://hdl.handle.net/10161/10660.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Margarethe Joanna Kuehn
Associate Professor of Biochemistry
Enterotoxigenic E. coli (ETEC) causes traveler's diarrhea and infant mortality in
underdeveloped countries, and Pseudomonas aeruginosa is an opportunistic pathogen
for immunocompromised patients. Like all gram negative bacteria studied to date, ETEC
and P. aeruginosa produce small outer membrane vesicles that can serve as delivery
"bombs" to host tissues. Vesicles contain a subset of outer membrane and
soluble periplasmic proteins and lipids. In tissues and sera of infected hosts,

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