Microbial biocontainment is an essential goal for engineering safe, next-generation living therapeutics. However, the genetic stability of biocontainment circuits, including kill switches, is a challenge that must be addressed. Kill switches are among the most difficult circuits to maintain due to the strong selection pressure they impart, leading to high potential for evolution of escape mutant populations. Here we engineer two CRISPR-based kill switches in the probiotic Escherichia coli Nissle 1917, a single-input chemical-responsive switch and a 2-input chemical- and temperature-responsive switch. We employ parallel strategies to address kill switch stability, including functional redundancy within the circuit, modulation of the SOS response, antibiotic-independent plasmid maintenance, and provision of intra-niche competition by a closely related strain. We demonstrate that strains harboring either kill switch can be selectively and efficiently killed inside the murine gut, while strains harboring the 2-input switch are additionally killed upon excretion. Leveraging redundant strategies, we demonstrate robust biocontainment of our kill switch strains and provide a template for future kill switch development.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8813983 | PMC |
| http://dx.doi.org/10.1038/s41467-022-28163-5 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
To kill or to piggyback: Switching of viral lysis-lysogeny strategies depending on host dynamics.
Sci Total Environ
December 2024
Archaeal Biology Center, Synthetic Biology Research Center, Shenzhen Key Laboratory of Marine Microbiome Engineering, Key Laboratory of Marine Microbiome Engineering of Guangdong Higher Education Institutes, Institute for Advanced Study, Shenzhen University, Shenzhen 518055, PR China. Electronic address:
Viruses wield significant influence over microbial communities and ecosystem function in marine environments. However, the selection of viral life strategies and their impacts on microbial communities remains enigmatic. In this study, we utilized a large-scale macrocosm, established using water samples from a marine coastal region, to enable community-level investigation.
View Article and Find Full Text PDFMicrofluidic chip systems for characterizing glucose-responsive insulin-secreting cells equipped with FailSafe kill-switch.
Stem Cell Res Ther
December 2024
Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada.
Background: Pluripotent cell-derived islet replacement therapy offers promise for treating Type 1 diabetes (T1D), but concerns about uncontrolled cell proliferation and tumorigenicity present significant safety challenges. To address the safety concern, this study aims to establish a proof-of-concept for a glucose-responsive, insulin-secreting cell line integrated with a built-in FailSafe kill-switch.
Method: We generated β cell-induced progenitor-like cells (βiPLCs) from primary mouse pancreatic β cells through interrupted reprogramming.
Influence of Environmental Conditions on the Escape Rates of Biocontained Genetically Engineered Microbes.
Environ Sci Technol
December 2024
Department of Energy, Environmental, and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
The development of genetically engineered microbes (GEMs) has resulted in an urgent need to control their persistence in the environment. The use of biocontainment such as kill switches is a critical approach to prevent the unintended proliferation of GEMs; however, the effectiveness of kill switches─reported as escape rates, i.e.
View Article and Find Full Text PDFOptimising Control Device Luring Strategies for Invasive Predator Control: A Modelling Approach.
Ecol Evol
December 2024
Manaaki Whenua - Landcare Research Lincoln New Zealand.
Invasive predators pose a serious threat to native biodiversity, with trapping being one of several methods developed to manage and monitor their populations. Many individuals in these predator populations have been found to display trap-shyness, which hinders eradication and results in inaccurate estimates of population size. Lures are used to help overcome trap-shyness by increasing the probability of interaction with the device, but the extent of trap-shyness in wild populations, and the best timing for the introduction of a new lure or combination of lures, are uncertain.
View Article and Find Full Text PDFAnti-HIV-1 HSPC-based gene therapy with safety kill switch to defend against and attack HIV-1 infection.
bioRxiv
November 2024
UCLA AIDS Institute, UCLA, Los Angeles, CA, USA, 90024.
Article Synopsis
- HSPC-based gene therapy shows potential for long-term HIV-1 remission after a single treatment, using a lentiviral vector to deliver three anti-HIV-1 genes.
- Two of the genes focus on preventing infection by targeting the CCR5 co-receptor and inhibiting fusion of the virus, while the third gene is designed to attack infected cells.
- The therapy was successful in humanized mouse models, significantly reducing HIV-1 viral load and allowing for safe removal of modified cells if necessary, demonstrating both effectiveness and safety of the approach.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!