Vectors retroviral genome

Some 24 per cent of all gene therapy clinical trials undertaken to date have employed retroviral vectors as gene delivery systems. Retroviruses are enveloped viruses. Their genome consists of ssRNA of approximately 5-8 kb. Upon entry into sensitive cells, the viral RNA is reverse transcribed and eventually yields double-stranded DNA. This subsequently integrates into the host cell genome (Box 14.1). The basic retroviral genome contains a minimum of three structural genes ... 

Fig. 6.4. Retroviral vectors. A. Structure of the provirus or the DNA copy of the retroviral genome. B and C. Prototype retroviral vectors approved for use in gene therapy protocols. ADA, adenosine deaminase LTR, long-terminal repeat RTase, reverse transcriptase.

Figure 14.4 Schematic representation of (a) the proviral genome of a basic retrovirus and (b) the genome of a basic engineered retroviral vector carrying the gene of interest. Refer to text for further details...

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