Switching on the lights for gene therapy

Area of Science:

• Molecular Biology
• Biotechnology
• Medical Imaging

Background:

• Non-invasive, quantitative imaging of in vivo gene expression is crucial for understanding disease mechanisms and gene therapy.
• Assessing gene regulation dynamics aids in detecting endogenous biological alterations and monitoring therapeutic gene induction.

Purpose of the Study:

• To demonstrate the feasibility of non-invasive imaging for regulated gene expression in vivo using versatile vectors.
• To generate regulatable herpes simplex virus type 1 (HSV-1) amplicon vectors for monitoring gene expression dynamics.

Main Methods:

• Generated HSV-1 amplicon vectors with hormone (mifepristone) or antibiotic (tetracycline) regulated promoters.
• Engineered vectors for proportional co-expression of two marker genes.
• Monitored gene expression using fluorescence microscopy in culture, and positron emission tomography (PET) or bioluminescence imaging (BLI) in vivo.

Main Results:

• Demonstrated successful in vivo monitoring of regulated gene expression using the developed vectors.
• Observed varying induction levels in glioma models dependent on inductor dosage.
• Validated PET and BLI as effective tools for assessing gene expression in animal models and potential human applications.

Conclusions:

• The generated regulatable HSV-1 amplicon vectors provide a versatile platform for non-invasive gene expression monitoring.
• These vectors facilitate the study of gene regulation dynamics in research settings with potential for clinical translation.
• Co-expression of marker genes with the gene of interest allows for proportional imaging of gene activity.