Table 1 Comparison between the cytoplasmic RNA viruses and the currently used RNA and DNA viruses for RNAi-based therapy
From: Cytoplasmic RNA viruses as potential vehicles for the delivery of therapeutic small RNAs
Genus | Main representative | Genome(sense) | Genome size (Kb) | Immuno-genicity | Expression level | Genomic insertion | Time of expression | Advantages | Limitations |
|---|---|---|---|---|---|---|---|---|---|
Alphavirus | Sindbis virus | ssRNA (+) | 12 | High | High | No | Short-term | - Cytoplasmic replication allowing high expression levels and potential non-canonical processing of artificial miRNAs. | Toxicity due to viral replication (non-cytopathic vectors overcome this limitation) |
- Apoptosis induction, they can be considered in Cancer gene therapy applications. | |||||||||
- Infect neurons in primary and cell lines, could be good candidates for gene therapy in Central Nervous System (CNS) | |||||||||
Flavivirus | West Nile virus, Tick-borne encephalitis virus | ssRNA (+) | 11 | Medium | High | No | Short-term | - Cytoplasmic replication allowing high expression levels and potential non-canonical processing of artificial miRNAs. | Toxicity (non-cytopathic vectors available Pre–existing immunity mainly in (sub)tropical countries |
- Genetic structure allow easy manipulation | |||||||||
Vesiculovirus | Vesicular stomatitis virus | ssRNA (-) | 11 | High | High | No | Short-term | - Cytoplasmic replication allowing high expression levels and potential non-canonical processing of artificial miRNAs. | Very sensitive to the antiviral action of interferon |
- Apoptosis induction, they can be considered in cancer therapy | |||||||||
Lentivirus | Human immunodeficiency virus type 1 | ssRNA (+) | 8 | Low | High | Yes | Long-term | Persistent gene transfer in most tissues | Integration might induce oncogenesis |
Dependovirus | Adeno-associated virus serotype 2 | ssDNA | <5 | Low | High | Yes | Long-term | Non-pathogenic parental viruses | Integration might induce oncogenesis |
Herpesvirus | Herpes simplex virus type 1 | dsDNA | 150 | High | High | No | Short-,Medium-term | Well suited as oncolytic vector and CNS applications (retrograde axonal transport) | Risk of recombination with latently herpes simplex virus-infected cells |