This article continues the same theme and reports further work in the School of Chemical Engineering on optimising production of gene therapy vectors. Recent advances in molecular biology and recombinant DNA technology have revealed the potential of gene therapy to cure such diseases. On the other hand the integration and expression of foreign genes into human cells is naturally performed by some viruses to ensure their own survival and vectors based on retroviruses are currently being employed in most gene therapy clinical trials. This unique property of retroviruses is vital for their propagation.
Retroviruses only infect vertebrate cells.
Infection of a cell with a retrovirus has little or no effect on cell function, hence this virus type has been exploited by researchers to integrate foreign genes into human cells. The latter are released by budding from the cell plasma membrane. This life cycle does not cause cell lysis and the cells are able to continuously release new virus particles. Hence any foreign gene inserted into the genome of a retrovirus will be produced indefinitely by the infected cells and their progeny. To use virus particles as 'vehicles' for therapeutic genes, the virus life cycle must be altered.