1. wound healing involves a complex series of biochemical events that progress in distinct stages:...

1.

Wound healing involves a complex series of biochemical events that progress in

distinct stages: inflammation, proliferation and remodeling. While tissue repair

takes place during the proliferative and remodeling stages, chronic wounds resulting

from inflammatory bowel disease (IBD) are locked in an inflammatory state and

resist the body’s natural ability to repair tissue.

According to the Centers for Disease Control, IBD is 1 of the 5 most prevalent

gastrointestinal diseases in the United States, accounting for 100,000

hospitalizations and $1.7 billion dollars in health care costs each year. With only a

few durable treatments, these disorders remain without a cure.

Introduction

Approach

Towards Intelligent ProbioticsChris Brasseaux, David Golynskiy, Tyler Guinn, Sameer Sant,

Mitu Bhattatiry, Nimi Bhattatiry, Alfredo Flores

Control Unit Immunobot

KillbotImmunobot

Sensor Interface Taxis

Applications

Characterization

Design

Scheme

Probiotics are living microorganisms that can confer a benefit to their host. Live

cultures present in regular yogurt products are examples of everyday probiotics.

We imagined an intelligent probiotic that can process inputs that indicate tissue

damage and produce a programmed output. While the human body itself consists

of 100 trillion cells, the bowel hosts 10 times as many microorganisms that exist as

part of a mutually beneficial symbiotic relationship. This incredible diversity of

symbionts represents a potentially powerful engineering platform for intelligent

probiotics that address IBD.

In 2009, Stanford developed a two-component probiotic that regulates the activity

of Th17 and Treg lymphocytes in order to control tissue inflammation and allow

normal wound healing to proceed into the proliferative and remodeling phases.

We aimed to build on their work in two ways: i) by engineering a wound sensing

ability into E. coli, and ii) by developing a means for the user to control probiotic

activity.

This work has applications in health and medicine. Our engineered two-

component system can be integrated with devices that recruit wound repairing

agents at the site of tissue damage. More broadly, intelligent probiotics offer

great promise as therapeutic tools for health-related issues such as devices that

can process inputs such as nutrient imbalances and affect balance-restoring

outputs.

Construct 1

Intracellular levels of CheY-P and CheY control flagellar motors

(FliM). High [CheY-P] results in “tumbles” (no net movement)

whereas high [CheY] results in “runs” (straight-line movement).

FGFR-ToxR chimeric receptor activates CTX-controlled

chemotaxis, thus connecting FGF wound signaling to

movement.

Fibroblast growth factor (FGF), a wound signal, induces the

dimerization of FGF receptor (FGFR), triggering FGF signal

transduction.

Construct 3Construct 2

Time

Delivery/Glucose

Population 1 (Immunobot) Population 1 (Immunobot) + more Population 2 (Killbot)

Population 1 (Immunobot) + Population 2 (Killbot)

Immunobot Experiments

Killbot Experiments

Modeling and SimulationsActivation of

Receptor

Dimerization of Receptor

Transcription and translation of CheZ

Dephosphorylation of CheY

Prediction of tumbling activity

Acknowledgements

Human Practices

Accomplishments

Recent global health concerns have focused greater attention on development assistance measures

oriented towards addressing chronic health diseases. Advancements in synthetic biology, such as

intelligent probiotics, may serve as important tools to enhance current global health initiatives. They

may be engineered to recognize issue-specific signals that elicit issue-specific responses, thus enhancing

approaches taken towards achieving the first UN Millennium Development Goal: curbing global

malnutrition and hunger. Intelligent probiotics provide potential applications in the grand strategic

approach to global health, or the practice of “achieving large ends with limited means.” In context of

health-oriented grand strategy outlined by Curry et al., applications of intelligent probiotics can employ

the following principles:

I. Start with the goal in mind

UTD iGEM’s end goal was the development of an intelligent probiotic using an E.coli chassis, a bowel

symbiont. As a proof of purpose, our application involved mitigating inflammatory bowel disease.

II. Tactics matter

It may prove less resource intensive to improve the efficiency of existing materials (probiotics) at

addressing the issue of malnutrition rather than simply channeling more resources into combating the

problem.

III. Take an ecological approach

On a microscale, our approach involved two goals: i) engineering wound sensing ability (immunobot)

and ii) enabling population control (killbot). Killbots were developed as a biosafety tool to manage

unintended consequences associated with using immunobots. On a macroscale, we attempt to illustrate

the utility of intelligent probiotics to global health organizations currently grappling with the

malnutrition issue. Our system may enhance the effectiveness of current initiatives by making them

more cost-effective.

Hence, we believe that grand strategic thinking in synthetic biology will better help connect future

developments in biotechnology with their intended beneficiaries.

We would like to express our sincerest thanks to the following people for their generous support during our iGEM experience:• To our mentors whose guidance which was invaluable to the success of our project.• To Kristina Ehrhardt, Neha Kashyap, and Lagnajeet Pradhan who provided additional

support carrying out experiments and also encoding the wiki and Android apps.• To UT Dallas for providing a facility to carry out our lab experiments.• To Dr. Ruth Silversmith (UNC School of Medicine) and Ms. Britta Herzog (University

of Göttigen) for providing us some important constructs. • To the Institute of Biological Engineering for hosting us at the Americas Jamboree.• To iGEM for giving our team this incredible opportunity.

• Entered information detailing at least one new standard BioBrick (BBa_K569001) in the Registry of Standard Biological Parts.

• Demonstrated that at least one new BioBrick (BBa_K569001) of our own design and construction works as expected. We also characterized its operation and entered this information and other documentation on the appropriate Registry page.

• Improved the characterization of BBa_K131010, an existing BioBrick, and entered our experience in the appropriate Registry page.

• Outlined and detailed a new grand strategic approach to Human Practices in connecting intelligent probiotics with ongoing initiatives in the global health arena to enhance their impact.