[P006] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P03-318] Inter-kingdom adrenergic signaling enables stress hormone sensing and programmable biological output

Santosh Kumar Srivastava^1,2,3, ○Guo Wei Foo^1,2,3, Nikhil Aggarwal^1,2,3, Matthew Wook Chang^1,2,3,4 (1. NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore (Singapore), 2. Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore (Singapore), 3. National Centre for Engineering Biology (NCEB) (Singapore), 4. Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (Singapore))

Keywords:

Inter-kingdom adrenergic signaling,Catecholamine neurohormones,QseBC Two-component system,Escherichia coli Nissle 1917,Corticotropin-releasing factor (CRF)

Host stress elevates catecholamine neurohormones that modulate gut physiology and host–microbe interactions, yet how bacteria detect and interpret these signals remains unclear. Enteric pathogens exploit inter-kingdom adrenergic signaling to sense host-derived norepinephrine and epinephrine, but the rational rewiring of such pathways for predictable, programmable outputs has not been systematically explored. Here, we reconstituted adrenergic signaling in Escherichia coli Nissle 1917 by repurposing the enterohemorrhagic E. coli QseBC two-component system. Transcriptomic profiling confirmed robust catecholamine-dependent activation of QseBC-regulated pathways. Guided by these data, we engineered a QseBC-responsive promoter derived from the flhDC regulatory region through truncation, sigma-factor binding site replacement, and optimization of QseBC expression. The resulting synthetic promoter exhibited enhanced sensitivity and dose-dependent responsiveness to norepinephrine and epinephrine, further improved by incorporating dual QseB binding motifs. Structure-guided mutagenesis of the QseC sensor kinase identified residues critical for catecholamine recognition, providing mechanistic insight into adrenergic sensing. To link sensing with function, we coupled the system to a secretion cassette encoding a corticotropin-releasing factor (CRF) receptor antagonist. In vitro validation in Caco-2 and THP-1 models demonstrated improved epithelial barrier integrity and reduced pro-inflammatory cytokine production. Together, this work establishes a framework for engineering inter-kingdom signaling into programmable microbial systems.