Inter-kingdom Signalling: Interaction of Quorum sensing molecules with mammalian immune cells

Acyl‐homoserine lactones (AHL) such as N‐3‐oxo‐dodecanoyl‐L‐homoserine lactone (3O-C12-HSL) 1, known as quorum sensing molecules, play an important role in the context of bacterial infection and biofilm formation. Recent studies have shown however, that these molecules are not only involved in bacterial communication, the so-called Quorum Sensing, but also cause effects in eukaryotic cells and organisms.



So far, little is known about the detailed mechanism of how AHL interacts with mammalian cells, and a receptor for AHL inside or on cell surface has not yet been clearly identified and characterised.

In detail, the following question will be addressed: (1) Is there a receptor for AHL on or in mammalian cells (e.g. PMNs); (2) does AHL enter the cell in a non-selective, random manner?

An experimental set-up to investigate the interaction of AHL with artificial membrane systems (supported lipid bilayers, SLB) using sum frequency generation (SFG) spectroscopy is shown in the figure below.

(A) Synthesis of deuterated AHL probes, e.g. 3OC12-HSL; (B) Monitoring the insertion of deuterated 3OC12-HSL into artificial membranes via SFG


Jakubczyk, D. / Barth, C. / Kubas, A. / Anastassacos, F. / Koelsch, P. / Fink, K. / Schepers, U. / Brenner-Weiß, G. (2012): „Deuterium-labelled N-acyl-l-homoserine lactones (AHLs)—inter-kingdom signalling molecules—synthesis, structural studies, and interactions with model lipid membranes“. In: Analytical and Bioanalytical Chemistry 2 (2012), 403, 473-482

Barth, C. / Jakubczyk, D. / Kubas, A. / Anastassacos, F. / Brenner-Weiss, G. / Fink, K. / Schepers, U. / Bräse, S. / Koelsch, P. (2012): „Inter-Kingdom signalling: Integration, Conformation and Orientation of N-Acyl-L-Homoserine Lactones in Supported Lipid Bilayers”. In: Langmuir (2012)

Jakubczyk, D. / Merle, C. / Brenner-Weiss, G. / Luy, B. / Bräse, S. / (2012): „Deuterium and Tritium Labelling of N-Acyl-L-homoserine Lactones (AHLs) by Catalytic Reduction of a Double Bond in the Layer-by-Layer Method”. In: European Journal of Organic Chemistry 23 (2012), 5323-5330