Engineering Gac/Rsm signaling cascade for optogenetic induction of pathogenicity switch inPseudomonas aeruginosa

Abstract

Bacterial pathogens operate by tightly controlling the virulence to facilitate invasion and survival in host. Although pathways regulating virulence have been defined in detail and signals modulating these processes are gradually understood, a lack of controlling infection signaling cascades of pathogens when and whereabouts specificity limits deeper investigating of host-pathogen interactions. Here, we employed optogenetics to reengineer the GacS of Pseudomonas aeruginosa, sensor kinase of GacS/GacA TCS regulates the expression of virulence factors by directly mediating several sRNAs. The resultant protein YGS24 displayed significant light-dependent activity of GacS kinases in Pseudomonas aeruginosa. When introduced in Caenorhabditis elegans host systems, YGS24 stimulated the pathogenicity of PAO1 in BHI and of PA14 in SK medium progressively upon blue-light exposure. This optogenetic system provides an accessible way to spatiotemporally control bacterial pathogenicity in defined host even specific tissues to develop new pathogenesis systems, which may in turn expedite development of innovative therapeutics.

Programming the lifestyles of engineered bacteria for cancer therapy

“…Using optogenetics, we 5 / 42 developed a genetic circuit in engineered bacteria that allows dynamic manipulation of bacterial lifestyles (planktonic, biofilm and lysis lifestyle) to precisely control the process of bacterial adhesion, colonization and drug release, with near-infrared (NIR) light in the BMCT process. The deep tissue penetration of NIR enables us a spatiotemporal and noninvasive control of genetic circuit [36,37] and is widely used to trigger certain behaviors of bacteria in vivo [38,39]. In addition, the LPD of NIR used to program the lifestyles of engineered bacteria H017 shows a reduction of 3 orders of magnitude compared to that of bacteria-based photothermal therapy (PTT) [40,41], which enables widespread clinical use outside of dermatological indications.…”