Type iv pilus of pseudomonasaeruginosa confers resistance to antimicrobial activities of the pulmonary surfactant protein-a

Rommel Max Tan, Zhizhou Kuang, Yonghua Hao, Gee W. Lau

Research output: Contribution to journalArticlepeer-review

Abstract

Pseudomonasaeruginosa(PA) is a Gram-negative bacterial pathogen commonly associated with chronic lung infections. Previously, we have identified several PA virulence factors that are important for resistance to the surfactant protein-A (SP-A), a pulmonary innate immunity protein that mediates bacterial opsonization and membrane permeabilization. In this study, we demonstrate that the type IV pilus (Tfp) is important in the resistance of PA to the antibacterial effects of SP-A. The Tfp-deficient mutant ΔpilA is severely attenuated in an acute pneumonia model of infection in the lungs of wild-type mice, but is virulent in the lungs of SP-A-/- mice. The ΔpilA bacteria are more susceptible to SP-A-mediated aggregation and opsonization. In addition, the integrity of the outer membranes of ΔpilA bacteria is compromised, rendering them more susceptible to SP-A-mediated membrane permeabilization. By comparing Tfp extension and retraction mutants, we demonstrate that the increased susceptibility of ΔpilA to SP-A-mediated opsonization requires the total absence of Tfp from PA cells. Finally, we provide evidence of increased expression of nonpilus adhesin OprH that may serve as an SP-A ligand, resulting in increased phagocytosis and preferential pulmonary clearance of ΔpilA.

Original languageEnglish (US)
Pages (from-to)227-239
Number of pages13
JournalJournal of Innate Immunity
Volume6
Issue number2
DOIs
StatePublished - Feb 2014

Keywords

  • Adhesins
  • Membrane permeabilization
  • Opsonization
  • Pseudomonas aeruginosa
  • Surfactant protein-A
  • Type IV pilus

ASJC Scopus subject areas

  • Immunology and Allergy

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