7.1.1 Retrovirus Vectors

Retrovirus is a virus that infects animal cells. Structurally, it is composed of a protein coat and genetic material made of RNA. It has a unique life cycle. The virus attaches itself to a specific cell surface receptor, then it enters the cell.  Inside the cell, the RNA genome is copied by an enzyme reverse transcriptase to form DNA. This DNA is then integrated into the host genome randomly, to form a provirus encodes to form more copies of viral RNA and protein envelopes to form new viruses. The newly produced viruses leave the cell by budding off from the cell carrying the part of the outer membrane (Fig. 9)

Figure 9 : Retrovirus life cycle

The retroviral vectors were first described to be used for gene therapy by Wei et al (1981) and the first patient was treated for adenosine deaminase deficiency was carried out by Anderson et al 1990.