Nano-guided cell networks as conveyors of molecular communication

Abstract

Advances in nanotechnology have provided unprecedented physical means to sample molecular space. Living cells provide additional capability in that they identify molecules within complex environments and actuate function. We have merged cells with nanotechnology for an integrated molecular processing network. Here we show that an engineered cell consortium autonomously generates feedback to chemical cues. Moreover, abiotic components are readily assembled onto cells, enabling amplified and ‘binned' responses. Specifically, engineered cell populations are triggered by a quorum sensing (QS) signal molecule, autoinducer-2, to express surface-displayed fusions consisting of a fluorescent marker and an affinity peptide. The latter provides means for attaching magnetic nanoparticles to fluorescently activated subpopulations for coalescence into colour-indexed output. The resultant nano-guided cell network assesses QS activity and conveys molecular information as a ‘bio-litmus' in a manner read by simple optical means.

Engineering Escherichia coli for enhanced sensitivity to the autoinducer‐2 quorum sensing signal

“…sfGFP expression was tested in both MDAI2 and CT104 containing plasmid pCT6 and either pET‐sfGFP, pET‐sfGFP‐LsrK, or pET‐sfGFP‐LsrACDB for AI‐2 concentrations ranging from 0 to 40 μM (Figure ). As expected, both the number of fluorescing cells and the intensity of fluorescence were generally higher in CT104 than MDAI2 . The lack of AI‐2 degrading proteins likely allows prolonged activation of the lsr promoter resulting in measurable levels of sfGFP even in cells with low intracellular AI‐2 levels.…”

“…Previously, we developed inducible AI‐2 controller cells with enhanced ability to uptake and respond to AI‐2 by manipulating the AI‐2 quorum sensing network through overexpression of proteins responsible for uptake and phosphorylation of AI‐2, specifically LsrACDB and LsrK . We have also engineered cells that autonomously activate protein expression based on accumulation of AI‐2 and demonstrated that deleting genes responsible for degrading and altering AI‐2, lsrF and lsrG , results in activation of protein expression at lower AI‐2 levels . In this paper, we demonstrate that combining these two strategies, use of an enhanced feedback loop through overexpression of LsrK and LsrACDB and deletion of lsrF and lsrG from the genome, can be used to engineer E. coli cells with enhanced sensitivity and ability to uptake and report on the presence of biologically relevant extracellular AI‐2 concentrations.…”

“…We next tested the enhanced feedback loop in host strain CT104. CT104 has previously been shown to be more sensitive to AI‐2 than MDAI2 . Here, we tested whether use of the enhanced feedback loop could further increase AI‐2 sensitivity in these cells.…”

Microbiome engineering: Current applications and its future

“…Humans Administration of SCFAs, LED209, tempol, AI-2, CAI-1 [18,19,26,[49][50][51][52][53]61] Treat or prevent disorders and diseases e.g. metabolic syndrome, obesity and cholera…”

Synthetic biology routes to bio-artificial intelligence

“…This opens exciting possibilities for implementing dynamical decision making using distributed SGNs. Terrel et al [34] also took a major step toward experimental implementation of distributed SGNs capable of classification. They demonstrated a system in which the presence of input was reported by a nanoparticle binding event that could occur only when two different cell types detected input signal.…”