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Long Term Chronic Pseudomonas aeruginosa Airway Infection in Mice
15:43

Long Term Chronic Pseudomonas aeruginosa Airway Infection in Mice

Published on: March 18, 2014

Murine complement interactions with Pseudomonas aeruginosa and their consequences during pneumonia

John G Younger1, Sunita Shankar-Sinha, Marc Mickiewicz

  • 1Department of emergency Medicine, Division of Pulmonary and Critical Care Medicine, Univeristy of Michigan, Ann Arbor, MI 48109-0303. jyounger@umich.edu

American Journal of Respiratory Cell and Molecular Biology
|September 23, 2003
PubMed

Insights

The complement system is crucial for fighting Pseudomonas aeruginosa lung infections. Complement deficiency increases mortality and lung injury, highlighting its role beyond phagocyte recruitment.

Area of Science:

  • Immunology
  • Microbiology
  • Pulmonary Medicine

Background:

  • The complement system is vital for host defense against bacterial lung infections.
  • Pseudomonas aeruginosa is a significant opportunistic pathogen causing lung infections.

Purpose of the Study:

  • To investigate the role of complement in defense against Pseudomonas aeruginosa lung infection.
  • To elucidate the in vitro interactions between complement and P. aeruginosa.
  • To assess the in vivo effects of complement depletion on host response and lung injury.

Main Methods:

  • In vitro serum bactericidal assays and complement pathway analysis.
  • In vivo complement depletion models in mice.
  • Assessment of bacterial clearance, inflammatory cell recruitment (neutrophils), and lung function (pressure-volume curves).

Main Results:

  • P. aeruginosa was resistant to direct serum killing but underwent C3 opsonization via alternative and mannose binding lectin (MBL) pathways.
  • Complement-deficient mice showed increased mortality and impaired bacterial clearance from the lungs.
  • Complement deficiency led to exacerbated lung injury and altered inflammatory responses, including increased chemokine KC levels.

Conclusions:

  • Complement activation on P. aeruginosa surfaces is essential for host survival during lung infection.
  • The complement system limits inflammatory responses and tissue damage, independent of phagocyte recruitment.
  • Targeting complement pathways could be a therapeutic strategy for P. aeruginosa lung infections.

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