Engineered Bacteria for Pulsatile Therapeutic Release
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Solution Overview
Problem
Current cancer therapies using engineered bacteria face challenges in safely avoiding systemic inflammatory responses while continuously producing anti-tumor agents locally within tumors, and existing methods lack dynamic control over colony growth and therapeutic expression.
Innovation Solution
Genetically engineered bacteria programmed to exhibit dynamic lysis at high cell densities, releasing genetically encoded therapeutic proteins, utilizing a genetic circuit with coupled positive and negative feedback loops to synchronize population growth and payload release within tumors, thereby maintaining a low bacterial population and avoiding immune responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engineered bacteria continuously produce anti-tumor agents within tumors, then therapeutic efficacy is improved, but systemic inflammatory responses are triggered
Solution Approach 1:
The patent implements periodic action through oscillatory lysis circuits that cause bacteria to lyse and release therapeutic payloads in periodic pulses rather than continuous release. The genetic circuit includes a lysis gene expressed under quorum sensing control, creating oscillations where bacterial populations grow to a threshold, then lyse and release therapy, followed by regrowth and subsequent lysis events. This periodic release maintains therapeutic efficacy while reducing continuous immune system activation.
Solution Approach 2:
The patent applies local quality by enabling bacteria to sense and respond to local tumor microenvironment conditions through quorum sensing mechanisms. The lysis gene expression is controlled by local bacterial population density signals (autoinducers), ensuring that lysis and therapeutic release occur only when sufficient bacterial accumulation has been achieved locally within the tumor. This localized control allows therapeutic action precisely where needed while avoiding systemic immune responses.
2Quantity of substance
If bacterial population density is increased to enhance therapeutic production, then anti-tumor agent availability is improved, but immune detection and clearance are increased
Solution Approach 1:
The patent implements feedback control through quorum sensing circuits where bacteria produce autoinducer molecules that accumulate with population density. When autoinducer concentration reaches a threshold, it triggers lysis gene expression, which reduces the bacterial population. This creates a negative feedback loop where the system self-regulates population density, ensuring sufficient numbers for therapeutic production while automatically preventing excessive accumulation that would trigger immune clearance.
Solution Approach 2:
The patent applies dynamics by creating a dynamic, oscillating bacterial population rather than a static high-density population. The population continuously cycles through growth phases (where numbers increase for therapeutic production) and lysis phases (where numbers decrease to avoid immune detection). This dynamic behavior allows the system to temporarily achieve high population densities needed for adequate therapeutic production while periodically returning to low densities that evade immune surveillance.
3Stability of the object's composition
If bacteria are engineered to release therapeutic proteins continuously, then treatment consistency is improved, but metabolic burden and loss of viability are increased
Solution Approach 1:
The patent implements periodic action by replacing continuous therapeutic production with oscillatory pulses of lysis and release. The genetic circuit is designed so that therapeutic proteins are produced intracellularly during bacterial growth phases, then released in pulses when lysis occurs. This periodic production pattern reduces the continuous metabolic burden of protein synthesis and secretion while maintaining treatment consistency through regular, predictable release cycles driven by quorum sensing timing.
Data Source
AI summary
Some embodiments described herein relate to cells which have been genetically engineered to release a polypeptide when a population of the cells reaches a desired density. In some embodiments, the released polypeptide may be a therapeutic polypeptide. In some embodiments, the therapeutic polypeptide kills tumor cells or which inhibits the growth of tumor cells.