Oscillatory expression of lentiviral transgenes

Although antiretroviral drugs can give people a normal life expectancy after HIV infection, they will still have HIV-infected cells throughout their life that make viruses and compromise their health. By contrast, in the field of gene therapy technology, cells that have been genetically instructed to continually make lentivirus frequently inactivate their viral genes and stop making virus, compromising the effetiveness of gene therapy production. The project aims to model, design, build and test a 'viroscillator' genetic circuit to extend the productive lifespan of stable lentiviral packaging cells. The performance of the resulting cells will be tested against conventional stable lentiviral packaging cell lines. The natural lentivirus, HIV-1, can achieve robust, persistent production of infectious viral particles in infected humans over decades, despite the fact high levels of expression of HIV-1 genes can lead to cell death. Insights gained from mathematical modelling of this system suggested opposing function of two HIV-1 genes act as positive and negative feedback loops respectively to bring about oscillation of viral genes overall. In this way the rate of production of lentiviral genes products is in constant flux, achieving sufficient yield of lentiviral protein over time, but never remaining at cytoxic production rate for long enough to select for a cell response. This project will test the hypothesis that an engineered oscillation of lentiviral genes can extend the productive lifespan of a stable lentiviral packaging cell lines.