Each year 10-20% of the US population is infected by the influenza virus, resulting in up to 40,000 deaths and 200,000 hospitalizations. While small molecules and vaccines have shown some benefit, the ability of the virus to mutate rapidly allows escape from such therapeutic pressure and drug-resistant forms are emerging. Furthermore, vaccine development is a prolonged process taking up to a year to identify a suitable formulation and the ability to supply sufficient material for vaccination of a large population faced with a pandemic can take even longer. Stockpiling such vaccines is one way to ensure sufficient supply but incurs huge costs and many such stockpiles expire before needed and have to be discarded. SiRNAs utilize an endogenous mechanism in mammalian cells to induce sequence and target-specific silencing of viral genes and prevent viral replication with a reduction in viral load that can have therapeutic benefits. The major challenge to utilization of siRNAs in a therapeutic or prophylactic approach is the ability to deliver these reagents to the tissues and cells within a patient where the virus causes its effects. This proposal seeks to use nanoparticle delivery of siRNAs able to specifically induce silencing of essential genes needed by the virus for survival and validate the ability to treat influenza in animals as a first step towards therapeutic development for treatment in Man. SiRNAs can be specifically designed in silico to reduce expression of viral gene targets while having no homology for host genes and therefore limited toxicity. SiRNAs can limit viral replication rates in vitro and results demonstrating efficacy of delivery in vivo against other viruses such as SARS corona virus have been published by members of our team. The ability to rapidly design and synthesize siRNAs against any gene, their stability for storage, ease of formulation, and the ability to deliver siRNAs against more than one viral target in the same vehicle make these agents valuable in initial defense against life-threatening pandemics. However, a barrier for their use in flu is the validation of a vehicle that can deliver siRNAs to the appropriate site(s) needed for therapeutic benefit. In early flu symptoms this target would be the lungs while systemic delivery will be required for later stages. Sirnaomics addresses these issues through proprietary nanoparticle delivery technologies that we have successfully used to demonstrate effective siRNA delivery and gene silencing through respiratory as well as systemic routes. This proposal seeks to use these vehicles in in vivo infection models to simultaneously deliver multiple siRNAs against key viral targets to increase efficacy while reducing opportunity for viral escape through mutation. The outcome form this work will be the identification of a novel therapeutic strategy for treatment of influenza. Future work will then allow migration of this cocktail through all the steps necessary to confirm its utility as a therapeutic in treating either seasonal flu or a pandemic.
Each year 10-20% of the US population is infected by the influenza virus, resulting in up to 40,000 deaths and 200,000 hospitalizations. While small molecules and vaccines have shown some benefit, the ability of the virus to mutate rapidly allows escape from such therapeutic pressure and drug-resistant forms are emerging. Furthermore, vaccine development is a prolonged process taking up to a year to identify a suitable formulation and the ability to supply sufficient material for vaccination of a large population faced with a pandemic can take even longer. Stockpiling such vaccines is one way to ensure sufficient supply but incurs huge costs and many such stockpiles expire before needed and have to be discarded. We propose to design siRNAs specifically able to silence viral genes essential for viral replication and use nanoparticle delivery of these siRNAs to validate the ability to treat influenza in animal models as a first step towards therapeutic development in Man. The ability to rapidly design and synthesize siRNAs against any gene, their stability for storage, ease of formulation, and the ability to deliver siRNAs against more than one viral target in the same vehicle make these agents valuable in initial defense against life-threatening pandemics and limits the ability for the virus to escape therapeutic pressure by mutation.
