Related Experiment Video

Updated: Jun 26, 2026

Generation of a Novel Dendritic-cell Vaccine Using Melanoma and Squamous Cancer Stem Cells
12:43

Generation of a Novel Dendritic-cell Vaccine Using Melanoma and Squamous Cancer Stem Cells

Published on: January 6, 2014

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

Mette E Skindersoe1, Louise H Zeuthen, Susanne Brix

  • 1Center for Biomedical Microbiology, Technical University of Denmark, Lyngby, Denmark.

FEMS Immunology and Medical Microbiology
|February 4, 2009
PubMed

Insights

Pseudomonas aeruginosa quorum-sensing molecules N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) and Pseudomonas quinolone signal (PQS) reduce interleukin-12 production by dendritic cells. This impairs T-cell proliferation and adaptive immune defense against infection.

Area of Science:

  • Microbiology
  • Immunology
  • Bacterial Pathogenesis

Background:

  • Pseudomonas aeruginosa virulence factors are regulated by quorum sensing.
  • N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) and Pseudomonas quinolone signal (PQS) are key quorum-sensing molecules.
  • These molecules have demonstrated immune-modulating properties.

Purpose of the Study:

  • To investigate the effects of OdDHL and PQS on cytokine production by bone marrow-derived dendritic cells (BM-DCs).
  • To determine the impact of OdDHL and PQS on T-cell responses.
  • To elucidate the dual role of these molecules in bacterial infection.

Main Methods:

  • Stimulation of BM-DCs with Escherichia coli lipopolysaccharide.
  • Treatment of BM-DCs with OdDHL and PQS.
  • Measurement of IL-12 and IL-10 cytokine production.
  • Assessment of T-cell proliferation following antigen stimulation of treated BM-DCs.

Main Results:

  • OdDHL and PQS significantly decreased IL-12 production by stimulated BM-DCs.
  • IL-10 release remained unaltered.
  • BM-DCs treated with OdDHL and PQS showed reduced capacity to induce T-cell proliferation in vitro.
  • A shift in DC maturation away from a pro-inflammatory T-helper type I response was observed.

Conclusions:

  • OdDHL and PQS act as immune modulators by suppressing IL-12 production and T-cell responses.
  • These molecules facilitate Pseudomonas aeruginosa infection by dampening adaptive immunity.
  • OdDHL and PQS exhibit dual functions: inducing virulence and modulating the host immune system.

More Related Videos

Time-lapse Imaging of Bacterial Swarms and the Collective Stress Response06:26

Time-lapse Imaging of Bacterial Swarms and the Collective Stress Response

Published on: May 23, 2020

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.08:11

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.

Published on: September 1, 2015

Related Concept Videos

Gene Regulation in Microbial Communities: Quorum Sensing01:28

Gene Regulation in Microbial Communities: Quorum Sensing

Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
Bacterial Signaling01:30

Bacterial Signaling

Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.