Alveolar response to Pseudomonas aeruginosa: role of the type III secretion system.

Details

Serval ID
serval:BIB_79599A2B0543
Type
Article: article from journal or magazin.
Collection
Publications
Title
Alveolar response to Pseudomonas aeruginosa: role of the type III secretion system.
Journal
Infection and immunity
Author(s)
Ader F., Le Berre R., Faure K., Gosset P., Epaulard O., Toussaint B., Polack B., Nowak E., Viget N.B., Kipnis E., Guery B.P.
ISSN
0019-9567 (Print)
ISSN-L
0019-9567
Publication state
Published
Issued date
07/2005
Peer-reviewed
Oui
Volume
73
Number
7
Pages
4263-4271
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
The type III secretion system (TTSS) is a specialized cytotoxin-translocating apparatus of gram-negative bacteria which is involved in lung injury, septic shock, and a poor patient outcome. Recent studies have attributed these effects mainly to the ExoU effector protein. However, few studies have focused on the ExoU-independent pathogenicity of the TTSS. For the present study, we compared the pathogenicities of two strains of Pseudomonas aeruginosa in a murine model of acute lung injury. We compared the CHA strain, which has a functional TTSS producing ExoS and ExoT but not ExoU, to an isogenic mutant with an inactivated exsA gene, CHA-D1, which does not express the TTSS at all. Rats challenged with CHA had significantly increased lung injury, as assessed by the wet/dry weight ratio for the lungs and the protein level in bronchoalveolar lavage fluid (BALF) at 12 h, compared to those challenged with CHA-D1. Consistent with these findings, the CHA strain was associated with increased in vitro cytotoxicity on A549 cells, as assessed by the release of lactate dehydrogenase. CHA was also associated at 12 h with a major decrease in polymorphonuclear neutrophils in BALF, with a proinflammatory response, as assessed by the amounts of tumor necrosis factor alpha and interleukin-1beta, and with decreased bacterial clearance from the lungs, ultimately leading to an increased mortality rate. These results demonstrate that the TTSS has a major role in P. aeruginosa pathogenicity independent of the role of ExoU. This report underscores the crucial roles of ExoS and ExoT or other TTSS-related virulence factors in addition to ExoU.
Keywords
Animals, Cell Line, Cytotoxins/metabolism, Humans, Interleukin-10/biosynthesis, Lung/pathology, Neutrophils/physiology, Protein Transport, Pseudomonas Infections/mortality, Pseudomonas aeruginosa/metabolism, Pseudomonas aeruginosa/pathogenicity, Pulmonary Alveoli/microbiology, Rats, Rats, Sprague-Dawley, Tumor Necrosis Factor-alpha/biosynthesis, Virulence Factors/metabolism
Pubmed
Web of science
Open Access
Yes
Create date
29/04/2021 9:59
Last modification date
17/07/2023 10:55
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