rAAV-CAG

Recombinant adeno-associated viruses (rAAVs) are widely used vectors in gene delivery due to their safety, efficiency, and ability to achieve long-term expression in various cell types. The inclusion of the CAG promoter, a hybrid promoter combining elements from the cytomegalovirus early enhancer (CMV), chicken β-actin promoter, and rabbit β-globin intron, further enhances rAAV utility.

Features of rAAV-CAG

• Versatility: The CAG promoter drives robust, ubiquitous, and high-level gene expression in both dividing and non-dividing cells.
• Cross-Species Compatibility: It is functional across a broad range of mammalian species, including humans, rodents, and primates.
• Target Specificity: When combined with tissue-specific enhancers or capsid-engineered rAAVs, it can achieve precise targeting in specific tissues (e.g., brain, liver, retina).

Applications of rAAV-CAG

• Gene Therapy:
  • Delivery of therapeutic genes for inherited diseases (e.g., hemophilia, retinal dystrophies).
  • Modulation of gene expression in neurodegenerative diseases (e.g., Parkinson's, Alzheimer's).
• Neuroscience Research:
  • Expression of optogenetic tools (e.g., channelrhodopsins) for circuit mapping.
  • Delivery of genetic reporters (e.g., GFP, GCaMP) for in vivo imaging.
• Functional Genomics:
  • Overexpression or knockdown of target genes to study gene function.
  • Use in CRISPR/Cas9-mediated genome editing.
• Developmental Biology:
  • Studying gene expression patterns during embryogenesis using reporter genes.

Advantages

• High expression driven by the CAG promoter.
• Long-term stability of expression due to episomal persistence.
• Minimal immune response in most systems.

Challenges

• Limited packaging capacity (~4.7 kb) of rAAV.
• Potential for off-target effects in non-specific applications.
• Scalability and production for large-scale studies or therapeutic use.

rAAV-CAG is a powerful tool in modern molecular biology, facilitating advances in gene therapy and functional studies across various disciplines.