Research Lecture at Nobel Forum
15 September, kl. 16.30
Bonnie L. Bassler
Professor in Molecular Biology
Department of Molecular Biology, Princeton University New Jersey, USA
Title: “Quorum Sensing and its Control”
Bacteria communicate with one another via the production and detection of secreted signal molecules called autoinducers. This cell-to-cell communication process, called “Quorum Sensing”, allows bacteria to synchronize behavior on a population-wide scale. Behaviors controlled by quorum sensing are usually ones that are unproductive when undertaken by an individual bacterium acting alone but become effective when undertaken in unison by the group. For example, quorum sensing controls virulence factor production, biofilm formation, and the excretion of public goods such as enzymes that solubilize solid food sources making them accessible for consumption. We developed small molecule quorum-sensing agonists and antagonists to discover the principles underlying the exquisite selectivity quorum-sensing receptors have for their cognate ligands. Our results suggest mechanisms bacteria use in the wild to ensure the proper ligand has interacted with its partner receptor prior to eliciting signal transduction. We suggest that, in their native environments, bacteria encounter mixtures of autoinducers produced by other species occupying the same niche. Precise autoinducer discrimination enables a particular species of bacteria to respond exclusively to its own signal even in the face of fierce competition. This ability prevents the leakage of benefits of quorum-sensing-controlled public goods to non-kin. Beyond learning about fundamental principles underlying quorum sensing, another use for our synthetic molecules is to control quorum sensing on demand. Indeed, our most potent quorum sensing antagonist protects animals from quorum-sensing-mediated killing by pathogenic bacteria and prevents biofilm formation in model microfluidics chambers that mimic medical devices. These results validate the notion that targeting quorum sensing has potential for antimicrobial drug development.