Despite impressive developments designing robust genetic circuits into bacteria, progress on the application of these approaches in complex environments has only recently been made and is still a general challenge. This is further complicated by issues arising from the release of engineered microbes into the environment, which may constitute ecological hazards. The primary goal of this project is to understand the interplay between environmental signals and synthetic genetic circuits. I will first design sensors that can probe and report on the local inflammatory conditions inside the intestine, which could ultimately be used as diagnostics. I will also design sensors that can detect environmental conditions indicative of being outside the gut (e.g., oxygen or drop in temperature) and will trigger a kill switch that will cause any released bacteria to self-destruct. These methods will quantitatively assess how environmental signals regulate engineered pathways as well as facilitate the safe application of engineered organisms into real-world contexts. The secondary goal is to create a foundation from which novel diagnostics and therapeutics can nondestructively function within the gut: a variable environment that is difficult to access. The gut microbiota maintains an intimate symbiotic relationship with the host; influencing multiple aspects of health, disease, and metabolism. Perturbations to its homeostasis can result in inflammatory and autoimmune diseases, transfer of antibiotic resistance, obesity and diabetes, inflammatory bowel disease, pathogenic infections, and cancer. Understanding the cross-talk between the host and microbiome will be invaluable for basic and translational research. Toward these ends, I will: 1. Understand signals of inflammation in the gut with bioengineered sensors. 2. Evaluate the environmental conditions necessary to eliminate engineered E. coli in a gut-on-a-chip device. 3. Test the impact of variable environmental stimuli on endogenous and abundant intestinal commensals. If implemented, this strategy could serve as an early detection system for infection, inflammatory bowel disease, and cancer. Using endogenous bacteria for safe, instantaneous, site-specific, and precise delivery of therapeutic compounds in response to environmental change could be tremendously advantageous for disease treatment and long-term health.

Public Health Relevance

My proposal focuses on the maintenance and containment of a stable bacterial community within a micro- engineered model of the human intestine and I seek to understand the interplay between environmental signals and genetic circuit function. These circuits?if applied to animal models?will safeguard the health of the host; ensuring the death of dysfunctional individuals and prevent environmental release and if implemented, these strategies could serve as an early detection system for infection, inflammatory bowel disease, and cancer. Future applications could use endogenous bacteria for safe, instantaneous, site-specific, and precise delivery of therapeutic compounds in response to environmental change, which would be tremendously advantageous for disease treatment and long-term health.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32DK112640-03
Application #
9687701
Study Section
Special Emphasis Panel (ZDK1)
Program Officer
Densmore, Christine L
Project Start
2017-05-01
Project End
2020-01-31
Budget Start
2019-05-01
Budget End
2020-01-31
Support Year
3
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Harvard University
Department
Type
Organized Research Units
DUNS #
082359691
City
Cambridge
State
MA
Country
United States
Zip Code
02138