In vitro reconstituted quorum sensing pathways enable rapid evaluation of quorum sensing inhibitors

Abstract

Quorum sensing, as inner- or inter-species microbial communication process orchestrated by diffusible autoinducers, typically results in collective pathogenic behaviours, being recognized as a promising druggable target for anti-virulence. Here, we reconstituted las and rhl quorum sensing pathways of Pseudomonas aeruginosa, mediated by acyl-homoserine lactones (AHLs) and LuxI/LuxR-family proteins, with fluorescence output in Escherichia coli cell-free expression system, offering a platform to rapidly evaluate quorum sensing inhibitors (QSIs) in vitro. Previously reported small-molecule quorum sensing inhibitors for interfering with P. aeruginosa quorum sensing systems were tested and showed mild to high on-target inhibition as well as off-target toxicity. Of note, quercetin displayed potent on-target inhibition to quorum sensing pathways as well as acceptable off-target toxicity to cell-free expression machinery. Upon our work, cell-free platform is anticipated to further facilitate automated and high-throughput drug screening, bridge in silico and in vivo drug-screening methods, and accelerate the upgrading of antimicrobial arsenal. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/466404v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1bf4161org.highwire.dtl.DTLVardef@15d775corg.highwire.dtl.DTLVardef@1475569org.highwire.dtl.DTLVardef@388e49_HPS_FORMAT_FIGEXP M_FIG C_FIG