Tuneable Conditional Control of Engineered Bacterial Therapeutics

Project Information

BACTOCONTROL

Grant agreement ID: 101113178

DOI

10.3030/101113178

Project closed

EC signature date 16 March 2023

Start date 1 April 2023

End date 31 March 2025

Funded under

• European Research Council (ERC)

Total cost

No data

EU contribution

€ 150 000,00

Coordinated by

INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE
France

Periodic Reporting for period 1 - BACTOCONTROL (Tuneable Conditional Control of Engineered Bacterial Therapeutics)

Reporting period: 2023-04-01 to 2025-03-31

Summary of the context and overall objectives of the project

Engineered microbes are attractive platforms for the diagnosis and treatment of several diseases. For example, bacteria can selectively target tumors and are ideal vehicles for in situ delivery of therapeutic agents. However, as of today, no engineered living bacterial therapeutics in clinical trials have the ability for conditional control of therapeutic activity. This lack of reliable control over the timing and dosage of effector molecule production limits the specificity, safety, and efficacy of current bacterial therapies. In this project, I will use of a generalizable synthetic receptor platform to control the in vivo therapeutic activity of engineered bacteria using an externally administered molecules. As a proof of concept, I will use a receptor responding to a molecule found in the diet to control therapeutic release in tumors. I will use a safe probiotic, E. coli Nissle 1917, with demonstrated tumor targeting properties. In a first research line, I will characterize the dose-response and kinetics of synthetic receptors implemented in bacteria colonizing an in vitro 3D tumor spheroids model. I will then evaluate the therapeutic activity of strains producing cytolytic molecules in response to external inducer. In a second research line, I will characterize conditional control of gene expression and then therapeutic release in tumor mice model, using cytolytic and immunotherapeutic effectors. My work will deliver robust, safe, and efficient frameworks for conditional control of bacterial cancer therapy. By enabling in situ drug delivery with a highly-precise dosage and timing, it will allow physicians and ultimately the patients to finely control bacterial therapeutic activity. Because of its modularity my platform will be further engineerable to detect other conditional inducers. This system will be reusable for the treatment of many other pathologies, including autoimmune and infectious diseases.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Work Package 1 focused on monitoring the colonization of therapeutic bacteria and assessing the functionality of biosensors for externally administered molecules in 3D tumor spheroids. Despite technical challenges in adapting the MC38 cancer cell line, a robust protocol for bacterial colonization was established, and an imaging protocol was developed to visualize GFP-expressing bacteria within spheroids. Induction in bacteria colonizing spheroids was demonstrated. However, some deliverables, such as induction kinetics and induction of bacterial oncolytic activity in 3D tumor spheroids, were not achieved.

Work Package 2 aimed to characterize the toxicity, biodistribution, pharmacokinetics, and therapeutic activity of therapeutic bacterial strains. A standardized protocol for bacterial counting using flow cytometry was optimized, and toxicity studies showed a dose-response correlation between bacterial concentration and mouse weight loss. Inducer pharmacokinetics were investigated, confirming detectable levels in tumors, and the functionality of the sensor was validated in vivo using luciferase as a reporter. Therapeutic effectors were tested, but no significant effect on tumor growth was observed. Some deliverables, such as nduction of bacterial oncolytic and immunotherapeutic activity in vivo, were not fully achieved.

In summary, the project successfully established protocols for bacterial colonization and induction by externally administered molecules in spheroids, optimized bacterial counting methods, and validated biosensor functionality in vivo. However, further optimization of the induction process and exploration of combination therapies are needed to enhance the efficacy of inducible bacterial cancer therapy.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The results of the BACTOCONTROL project have significant potential impacts in the field of bacterial therapeutics and cancer treatment. The establishment of robust protocols for bacterial colonization and gene induction in 3D tumor spheroids using externally administered molecules provides a valuable foundation for future research and therapeutic development. The optimization of bacterial counting methods and the validation of biosensor functionality in vivo are critical advancements that can enhance the precision and efficacy of bacterial therapies.

To ensure further uptake and success, several key needs must be addressed:

1. Further Research: Continued research is essential to optimize the induction process and explore combination therapies. This includes improving the stability, expression levels, and bioavailability of effector molecules, as well as investigating the potential of combining inducer-controlled bacterial cancer therapy with other therapeutic approaches, such as chemotherapy or radiation therapy.

2. Demonstration: Additional demonstration studies are needed to validate the efficacy and safety of bacterial cancer therapy in preclinical and clinical settings. This will involve conducting comprehensive in vivo studies and clinical trials to assess the therapeutic potential and long-term effects of the treatment.

3. Access to Markets and Finance: This was not planned nor adressed in this project as we were still at an early stage. Nevertheless, securing access to markets and finance is crucial for the commercialization and widespread adoption of the developed therapies. This includes attracting investment, forming strategic partnerships, and navigating regulatory pathways to bring the therapies to market.

4. Commercialisation: Developing a robust commercialization strategy is essential for translating the research findings into marketable products. This involves identifying target markets, establishing production and distribution channels, and creating a compelling value proposition for potential customers.This is still early in the project, we are now focusing on secruing IP and validating the technology.

5. Intellectual property rights (IPR) support is vital for protecting the innovative technologies and therapies developed during the project. during the duration of the project, the main patent protecting the invention was accepted in Japan and Europe, and we are in good positon to get it in the US.
Patent: Chang HJ, Bonnet J., “Chimeric Receptor For Use In Whole-cell Sensors For Detecting Analytes Of Interest”, Patent granted in 2024 in Europe (P3635398B1), Spain (ES2986584T3), and Japan (JP7265487B2) in process for US and WO. Initially filled in 2018.