Synthetic Biology-Based Engineering Living Therapeutics for Antimicrobial Application

Abstract

There is currently a pressing issue of antimicrobial resistance, with numerous pathogenic superbugs continually emerging, posing significant threats to both human health and the economy. However, the development of new antibiotics has not kept up in pace with the development of microbial resistance, necessitating the exploration of more effective approaches to combat microbes. Synthetic biology offers a novel paradigm by employing selective screening and assembling diverse biological components to redesign biological systems that can specifically target and eliminate microbes. In particular, engineering living therapeutics enables the detection and precise eradication of pathogenic microorganisms in a controlled means. This review provides an overview of recent advancements in engineering living therapeutics using synthetic biology for antibacterial treatment. It focuses on modifying bacteriophages, microbes, and mammalian cells through engineering approaches for antibacterial therapy. The advantages of each approach are delineated along with potential challenges they may encounter. Finally, a prospective outlook is presented highlighting the potential impact and future prospects of this innovative antimicrobial strategy.

Keywords: antimicrobial therapy; engineering living therapeutics; synthetic biology.

FIGURE 1

Modification and counter‐selection strategies for bacteriophage genome. (A) Modification of bacteriophage genome is achieved through homologous recombination. (B) BRED (bacteriophage recombineering of electroporated DNA) technique is employed to introduce bacteriophage DNA, template DNA, and the aforementioned recombinase system into host cells, thereby enhancing transformation efficiency. (C) Modification of bacteriophage genome is carried out utilizing the CRISPR‐Cas system. (D) The CRISPR‐Cas system is utilized for the selection of engineered bacteriophages.

FIGURE 2

Phage synthesis engineering. Designed and synthesized gene fragments undergo homologous recombination within yeast cells or are assembled into a specific bacteriophage genome in vitro. Subsequently, the assembled synthetic phage genome can be rebooted within host cells, L‐form bacteria, or by utilizing cell‐free TXTL (transcription–translation) technology. Ultimately, the specific bacteriophage generated is utilized for antibacterial therapy.

FIGURE 3

Sense‐killed system in engineering microbes. Engineered and modified microbes are designed to produce receptors or transcriptional factors that detect bacterial quorum‐sensing (QS) molecules (purple) or metabolites (green). Upon detection, the system triggers the production of molecules that are lethal to the bacteria.

FIGURE 4

Antibacterial mechanisms in engineered mammalian cells. Engineering mammalian cells to produce a biological sensor involves the detection of bacterial quorum‐sensing (QS) molecules. Additionally, toll‐like receptors can be utilized to recognize bacterial pathogen‐associated molecular patterns (PAMPs). Upon recognition, the cells secrete molecules that are directly lethal to bacteria. Besides, engineering mammalian cells may also produce substances that control QS molecules, leading to the quorum‐quenching and collective suppression of bacterial activity.