Table 2 General properties of the most commonly used viral vectors.
From: LDLR-Gene therapy for familial hypercholesterolaemia: problems, progress, and perspectives
Properties | Adenoviruses | AAV | Retroviruses | Lentiviruses |
|---|---|---|---|---|
Wild type viruses | 36 kb ds linear DNA | 4.7 kb ssDNA | 9.2 kb Diploid +ssRNA | 8-10 kb Diploid +ssRNA |
Pre-existing host antibodies | Yes | Yes | Unlikely | Unlikely but (may be in HIV +ve individuals) |
Packaging capacity | 8-30 kb | 4 kb | <8 kb | 8 kb expected |
Viral titre (particles/ml) | >1013 | >1012 | >109 | 109 |
Stability | Good | Good | Good | Not tested |
Integration | No | <10% integrated | Yes | Yes |
Cellular localisation | Nuclear | Nuclear | Nuclear | Nuclear |
Cell range | Non-replicating and replicating | Non-replicating and replicating | Replicating only | Non-replicating and replicating |
Levels of expression | Very high | Moderate | Moderate | Moderate |
Duration of expression | Transient | Long | Long, but subject to shutdown | Long |
Immune response | Extensive | Not known | Few neutralis-ing antibodies | Not known |
Safety issues | Inflammatory and toxicity | Rearrangement and inflammatory | Insertional mutagenesis | Insertional mutagenesis |
Main advantages | Extremely efficient transduction of most tissues | Non-inflammatory Non-pathogenic | Long-term gene transfer in dividing cells | Long-term gene transfer in dividing cells |
Main disadvantages | Capsid mediates a potent inflammatory response | Small packaging capacity | Transduces only dividing cells and potential for oncogenesis | Potential for oncogenesis |