Pseudomonas aeruginosa quorum-sensing signal molecules interfere with dendritic cell-induced T-cell proliferation

FEMS Immunol Med Microbiol. 2009 Apr;55(3):335-45. doi: 10.1111/j.1574-695X.2008.00533.x. Epub 2009 Jan 28.


Pseudomonas aeruginosa releases a wide array of toxins and tissue-degrading enzymes. Production of these malicious virulence factors is controlled by interbacterial communication in a process known as quorum sensing. An increasing body of evidence reveals that the bacterial signal molecule N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) exhibits both quorum-sensing signalling and immune-modulating properties. Recently, yet another quorum-sensing signal molecule, the Pseudomonas quinolone signal (PQS), has been shown to affect cytokine release by mitogen-stimulated human T cells. In the present article we demonstrate that both OdDHL and PQS decrease the production of interleukin-12 (IL-12) by Escherichia coli lipopolysaccharide-stimulated bone marrow-derived dendritic cells (BM-DCs) without altering their IL-10 release. Moreover, BM-DCs exposed to PQS and OdDHL during antigen stimulation exhibit a decreased ability to induce T-cell proliferation in vitro. Collectively, this suggests that OdDHL and PQS change the maturation pattern of stimulated DCs away from a proinflammatory T-helper type I directing response, thereby decreasing the antibacterial activity of the adaptive immune defence. OdDHL and PQS thus seem to possess dual activities in the infection process: as inducers of virulence factors as well as immune-modulators facilitating the infective properties of this pathogen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Butyrolactone / analogs & derivatives*
  • 4-Butyrolactone / metabolism
  • 4-Butyrolactone / pharmacology
  • Animals
  • Cell Proliferation*
  • Dendritic Cells / drug effects*
  • Homoserine / analogs & derivatives*
  • Homoserine / metabolism
  • Homoserine / pharmacology
  • Immunologic Factors / metabolism
  • Immunologic Factors / pharmacology*
  • Mice
  • Mice, Inbred C57BL
  • Pseudomonas aeruginosa / immunology*
  • Pseudomonas aeruginosa / metabolism
  • Quinolones / immunology*
  • Quinolones / metabolism
  • T-Lymphocytes / immunology*


  • 2-heptyl-3-hydroxy-4-quinolone
  • Immunologic Factors
  • N-(3-oxododecanoyl)homoserine lactone
  • Quinolones
  • Homoserine
  • 4-Butyrolactone