This article describes the administration of lux-tagged bacteria to mice and subsequent in vivo analysis using IVIS bioluminescence imaging.
This video describes the use of whole body bioluminesce imaging (BLI) for the study of bacterial trafficking in live mice, with an emphasis on the use of bacteria in gene and cell therapy for cancer. Bacteria present an attractive class of vector for cancer therapy, possessing a natural ability to grow preferentially within tumors following systemic administration. Bacteria engineered to express the lux gene cassette permit BLI detection of the bacteria and concurrently tumor sites. The location and levels of bacteria within tumors over time can be readily examined, visualized in two or three dimensions. The method is applicable to a wide range of bacterial species and tumor xenograft types. This article describes the protocol for analysis of bioluminescent bacteria within subcutaneous tumor bearing mice. Visualization of commensal bacteria in the Gastrointestinal tract (GIT) by BLI is also described. This powerful, and cheap, real-time imaging strategy represents an ideal method for the study of bacteria in vivo in the context of cancer research, in particular gene therapy, and infectious disease. This video outlines the procedure for studying lux-tagged E. coli in live mice, demonstrating the spatial and temporal readout achievable utilizing BLI with the IVIS system.
In the context of gene therapy, the use of biological agents for delivery of therapeutic genes to patients has shown great promise 3-5. Like viruses, the innate biological properties of bacteria permit efficient DNA delivery to cells or tissues, particularly in the context of cancer. It has been shown that bacteria are naturally capable of homing to tumors when systemically administered resulting in high levels of replication locally, either external to (non-invasive species) or within tumor cells (pathogens)….
The authors have nothing to disclose.
The authors wish to acknowledge support relevant to this manuscript from the European Commission Seventh Framework Programme (PIOF-GA-2009-255466) and the Irish Health Research Board (HRA_POR/2010/138). Lux-tagged E. coli was a kind gift from Dr. Cormac Gahan, University College Cork.
Name of the reagent | Company | Catalogue number | Comments |
4T1 cell line | ATCC | CRL-2539 | Syngeneic breast cancer model derived from a spontaneously arising BALB/c mammary tumor |
DMEM | Sigma-Aldrich | D6429 | Dulbecco’s Modified Eagle’s Medium |
PBS | Sigma-Aldrich | D8537 | Phosphate Buffered Saline |
Xenogen IVIS | Caliper Life Sciences | IVIS 100 for 2D imaging; IVIS Spectrum for 3D. | |
Luria Broth Miller (LB) | Sigma-Aldrich | L2542 | Growth medium for E. coli |
Erythromycin | Sigma-Aldrich | E5389 | Antibiotic |
Streptomycin | Sigma-Aldrich | S9137 | Antibiotic |
MF1nu/nu mice | Harlan (UK) | 069(nu)/070(nu/+) | Hsd:Athymic Nude-Foxn1nu |
Balb/c mice | Harlan (UK) | 066 | Haplotype: H-2d |
Gavage needle | Vet-tech Solutions (UK) | DE009 | 22G x 38mm straight gavage needle |
Syringe for IV injection | BD BioSciences | 309309 – 1 ml | Insulin syringe with 28 G x ½ inch micro-fine IV needle. |
Syringe for tumor inoculation | Braun | 9161376V | Omnifix 26 G x ½ inch needle |