Bacteria-Based Live Vehicle for In Vivo Bioluminescence Imaging

Abstract

The anticancer therapy strategy mediated by tumor-targeting bacteria needs better visualization tools for imaging and monitoring bacteria in vivo. The probiotic strain Escherichia coli Nissle 1917 (EcN), one of the tumor-targeting bacteria, leads to the potential application for cancer therapy. Here, we report the development and application of a live, EcN-based imageable vehicle for noninvasive in vivo bioluminescence imaging in live mice. Firefly luciferase (Fluc) and luciferin-regenerating enzyme (LRE), an enzyme that contributes to stable bioluminescence, were functionally coexpressed in EcN. The recombinant EcN strain expressing the genomically integrated Fluc-LRE cassette was demonstrated to be a valuable tool for generating robust, continuous, and red-shifted bioluminescence for bacterial tracking in vitro and in vivo, thus providing an optical tumor-targeting system for the in vivo study of bacteria-assisted cancer therapy. Additionally, in vivo imaging of the recombinant EcN strain in the mouse intestinal tract indicated the potential of this strain to be used as a tool in the study of gut.

New insight into the application of fluorescence platforms in tumor diagnosis: From chemical basis to clinical application

“…[192][193][194][195] In the field of tumor diagnosis, an in vivo imageable carrier based on tumor-targeting bacteria (EcN) has been applied for noninvasive in vivo luminescence imaging in mice. 196 This system utilizes recombinant EcN strains to simultaneously express firefly luciferase (Fluc) and luciferase regenase (LRE) to produce stable, continuous, and red-shifted bioluminescence, which provides a valuable reference for in vivo studies of bacterial-assisted cancer therapy. In addition, Professor Li Minyong's team is also committed to optimizing the firefly luciferase system.…”

“…The firefly luciferase system is the most widely used bioluminescence system, and a series of bioluminescence probes have been developed using this system for in vivo imaging of disease markers, and surprising imaging results have been achieved 192–195 . In the field of tumor diagnosis, an in vivo imageable carrier based on tumor‐targeting bacteria (EcN) has been applied for noninvasive in vivo luminescence imaging in mice 196 . This system utilizes recombinant EcN strains to simultaneously express firefly luciferase (Fluc) and luciferase regenase (LRE) to produce stable, continuous, and red‐shifted bioluminescence, which provides a valuable reference for in vivo studies of bacterial‐assisted cancer therapy.…”

Genetically engineered probiotics for an optical imaging-guided tumor photothermal therapy/immunotherapy

“…Fluorescence nanoparticles, magnetic nanoparticles and radioactive nuclide-labelled bacteria have been constructed for imagingguided BCT. [26][27][28] Owing to the convenience of biogenetic modification, bacteria were engineered to express fluorescence proteins or luciferase for in vivo optical tracking, 29,30 simplifying the construction of imageable bacteria, but usually showing negligible therapeutic effects for cancer treatment without any additional drug loading.…”

Advances in Escherichia coli Nissle 1917 as a customizable drug delivery system for disease treatment and diagnosis strategies

“…To achieve good drug adaptability in vivo , in addition to chemical materials, natural bionic delivery systems similar to cell membranes or bacteria have also been developed [ [4] , [5] , [6] ]. In contrast to ligand targeting of cell membrane and avoiding immune response in vivo , the bacterial delivery system provides additional functionality through drugs or modification, provided that bacteria maintain their original functions (for example, inhibit cancer by competing with tumor cells) [ [7] , [8] , [9] ]. Human diseases are closely related to bacteria.…”