Team:Warwick/Project/Applications

Due to the way in which the RNA strand was engineered, the construct can easily be altered to act as a chassis for any number of potential uses, both in siRNA and other genes. This is due to the presence of restriction sites abundant in our construct. One particularly current application is for the treatment of Ebola. Ebola has come to the forefront of public knowledge and fears due to the rampant outbreak in Africa which has resulted in a death toll of 9000 recorded deaths.

Ebola

Ebola is a viral haemorrhagic fever which attacks the blood vessels throughout the body causing internal and external bleeding and multiple organ failure leading to death in 50% of cases. The most recent outbreak of Zaire ebolavirus originated in Guinea and has now spread to many other countries in Africa including; Sierra Leone, Nigeria, Liberia and further afield with the first death in the U.S recorded in mid-October. The most effective treatment to date was ZMAPP, a combination of three humanised monoclonal antibodies used in tandem with rehydration to replenish water loss from hemorrhage reducing the mortality rate from 90% to 50%. There has recently been a worldwide exhaustion of reserves of ZMAPP which is complex and lengthy to prepare, therefore driving endeavors to find alternative therapies. The most promising of these is siRNA therapies targetting the Ebolavirus genome.




The siRNA is transfected into cells using lipid nanoparticle technology, as used in our transfection in vitro, and targets the L, VP24 and VP30 genes. This has been tested in chimpanzees and has shown reduction in Ebolavirus found in the blood when administered both pre and post infection, at the time when symptoms would present. If these siRNAs were inserted into our replicon it could be used as a prophylactic or post-infection treatment of those at risk or infected with, respectively, Ebola. This treatment has been fast tracked to Stage 3 clinical trials due to the severity of the disease.

Alzheimer's Disease


Another potential application for our replicon in an alternative location is Alzheimer's Disease. This is a neurodegenerative disorder usually affecting those in old age and causing memory loss, inflammation and neuronal cell death. These symptoms arise from the build-up of β-amyloid peptides causing neurofibrillary tangles in the brain. The disease shares a number of physiological markers with type II diabetes mellitus and shows an improvement in symptoms following administration of incretins. This is due to cAMP coupled incretin receptors present in the brain, suggesting a central role of these hormones in the regulation of neuronal function and plasticity as well as neuronal survival, which is severely reduced in those with Alzheimer's, as seen in the figure below.

The effect of long-term suppression of DPP-IV on the alzheimer's symptoms was investigated in D'Amico et al. 2009. The reduction in DPP-IV increases the life span of incretins such as GLP-1. Transgenic mice prone to the development of Alzheimer's, when administered with DPP-IV inhibitors, showed a significantly increased level of GLP-1 in a tissue assay and subsequently a reduction in nitrosative stress, inflammation and diminished build-up of β-amyloid peptides. This suggests that if the replicon was administered to neuronal cells, there may be an extension of neuronal cell life and aleviated symptoms of Alzheimer's, increasing the quality of life in old age.