Quorum-Quenching Human Designer Cells for Closed-Loop Control of Pseudomonas aeruginosa Biofilms

Abstract

Current antibiotics gradually lose their efficacy against chronic Pseudomonas aeruginosa infections due to development of increased resistance mediated by biofilm formation, as well as the large arsenal of microbial virulence factors that are coordinated by the cell density-dependent phenomenon of quorum sensing. Here, we address this issue by using synthetic biology principles to rationally engineer quorum-quencher cells with closed-loop control to autonomously dampen virulence and interfere with biofilm integrity. Pathogen-derived signals dynamically activate a synthetic mammalian autoinducer sensor driving downstream expression of next-generation anti-infectives. Engineered cells were able to sensitively score autoinducer levels from P. aeruginosa clinical isolates and mount a 2-fold defense consisting of an autoinducer-inactivating enzyme to silence bacterial quorum sensing and a bipartite antibiofilm effector to dissolve the biofilm matrix. The self-guided cellular device fully cleared autoinducers, potentiated bacterial antibiotic susceptibility, substantially reduced biofilms, and alleviated cytotoxicity to lung epithelial cells. We believe this strategy of dividing otherwise coordinated pathogens and breaking up their shielded stronghold represents a blueprint for cellular anti-infectives in the postantibiotic era.

Responsive Assembly of Silver Nanoclusters with a Biofilm Locally Amplified Bactericidal Effect to Enhance Treatments against Multi-Drug-Resistant Bacterial Infections

“…5,6 Worse still, conventional antibiotics show very limited effectiveness and induce antibiotic resistance of bacteria. 7−9 Biofilm formation is considered to be vital to the drug resistance of bacteria, 10−12 and the biofilm matrix acts as a natural barrier to drug penetration and activation. 13 The biofilm matrix containing exopolymeric substances (EPS) causes diffusion-reaction inhibition for antibiotics.…”

Smart-watch-programmed green-light-operated percutaneous control of therapeutic transgenes

“…Glow Control, based on non-invasive wearable consumer electronics interfacing a standard programmable green-light LED with biopharmaceutical production of engineered cells, provides a new level of control, which we have successfully validated for experimental diabetes treatment. The combination of Glow Control with non-invasive, continuous glucose monitoring 47 – 49 , 51 , 52 , 56 , 57 could eventually enable full closed-loop control, a cell-based treatment strategy 4 that has been used to cure a variety of experimental metabolic disorders 32 , 58 – 60 or infectious diseases 61 , 62 . To translate our proof-of-concept smart watch-controlled Glow Control system into clinical reality, it will be necessary to develop improved cell encapsulation strategies, including novel approaches and materials that ensure long-term cell survival.…”

From synthetic biology to human therapy: engineered mammalian cells

“…In contrast to AI-2, other autoinducers, such as Pseudomonas autoinducer (PAI) 1 and 2 promote biofilm formation. A nuclear autoinducer sensor was engineered to sense PAI-1 and in response activate expression of a combination of biofilm-and autoinducer-degrading enzymes [34] (Figure 3d). These studies showcase the effectiveness of therapeutics produced in vivo, even though the same molecules might be unsuited for traditional delivery routes due to low serum half-life or poor oral bioavailability.…”