Overview of Project DR. SWITCH (Disease-associated RNA Switch)
Our project focus on developing an on-site subtypting method for Influenza A virus subtype H5N1 and H7N9 using toehold switches. To facilitate future toehold switch project, we also developed an online software program for designing toehold switch, and constructed toehold switch cloning tool that allow easy construction and validation of toehold switches.
Influenza A is a rapid changing disease that causes 5,000,000 of death annually worldwide. Among different subtypes, highly pathogenic avian influenza has the highest mortality rate. Challenges of disease control in the modern world with high population mobility remains at the speed and accuracy of diagnosis. However, nowadays influenza A subtyping method rely greatly on RT-PCR, which requires long time, expertise and laboratory space. Meanwhile, a novel type of riboswitch, namely toehold switch, shows its potential in subtyping Influenza A with quicker detection and lower production cost.
By combining cell free system and toehold switch, a rapid on- site detection method for influenza A subtype H5N1 and H7N9 is designed and under investigation. It has high potential to be used widely in, but not limited to, animal farms, and border inspections and schools wherever expertise and laboratory equipment are not readily available.
We hope that our project can (i) provide rapid detection method with higher accuracy at a lower production cost; (ii) stop Influenza A pandemic by early on-site detection; and (iii) ease the stress on public health service when disease attacks, especially in less developed countries.
Influenza A can be spread rapidly throughout poultry flocks and cause severe illnesses, or even deaths in human. The most notorious pandemic was the "Spanish Flu" in 1918, which killed 50 million people worldwide (1). Influenza A virus poses large social and economic burden. Each year in the United States, it is estimated that around 600,000 lives and 90 billion US
dollars are lost due to influenza A virus (2). Influenza A can be subtyped according to the types of hemagglutinin (HA) and neuraminidase (NA) on the virus surface. Since there are 16 types of HA and 9 types of NA, there are 144 possible subtypes. Different Influenza A subtype show different properties. For example, the mortality rate of inflection by the subtypes H5N1 and H7N9 is much higher than that of H1N1.