Oscillatory expression of lentiviral transgenes

尽管抗逆转录病毒药物可以让人在感染艾滋病毒后获得正常的预期寿命，但他们一生中仍然会有艾滋病毒感染的细胞，这些细胞会制造病毒，危及他们的健康。相比之下，在基因治疗技术领域，被遗传指示不断使慢病毒持续存在的细胞经常使其病毒基因失活，并停止制造病毒，从而损害了基因治疗产品的有效性。该项目旨在建模、设计、建造和测试一个“病毒振荡器”基因电路，以延长稳定的慢病毒包装细胞的生产寿命。所得到的细胞的性能将与常规稳定的慢病毒包装细胞系进行测试。尽管HIV-1基因的高水平表达可能导致细胞死亡，但天然慢病毒HIV-1可以在数十年内在受感染的人类中实现强劲、持续的感染性病毒颗粒的产生。从该系统的数学模型中获得的见解表明，两个HIV-1基因的相反功能分别作为正反馈环和负反馈环，导致病毒基因的整体振荡。通过这种方式，慢病毒基因产物的生产速度处于恒定的流动中，随着时间的推移获得足够的慢病毒蛋白产量，但永远不会保持足够长的细胞毒性生产速度来选择细胞反应。该项目将测试这样一种假设，即通过设计慢病毒基因的振荡可以延长稳定的慢病毒包装细胞系的生产寿命。

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.