Flaviviruses are a single-stranded, positive sense, RNA virus that affect around 400 million people annually. Flaviviruses are transmitted by arthropod vectors, the most common vector being the mosquito. Currently, many mosquito control strategies are in use, these control strategies are diverse in both efficiency and cost. However, developing new vector control strategies is becoming increasingly important, due to climate changing affecting vector population distribution and the current limitations conventional control strategies face. Although many different control strategies exist, there is limited research pertaining to reducing viral infection in the vector. Reducing the transmission capabilities of vectors could help relieve the disease burden felt around the world. Aripo virus (ARPV), an insect-specific flavivirus, has ushered in opportunities to discover a novel approach to arbovirus control. The exclusionary effects of ARPV were explored as a means to eventually understanding superinfection exclusion (SIE) and utilizing it as a calculated defense against mosquito-borne disease. Aripo virus was evaluated for its SIE potential in vitro and experiments were performed to explore the possible mechanisms underlying SIE. Aripo virus showed significant exclusion against the flaviviruses tested, as well as an alphavirus. Additionally, West Nile virus was unable to adapt and overcome SIE barriers over 9 serial passages. Lastly, ARPV was superinfected with chimeric viruses to asses replication kinetics, and possible exclusionary bias
was seen with non-structural genes. These data show ARPV is capable of reducing viral titer, as well as possible leads into understanding the underlying mechanism of SIE, a critical step in utilizing SIE as a strategy to combat vector-borne disease. / Master of Science in Life Sciences / Mosquitoes all around the globe spread disease causing pathogens. Infection with viral pathogens such as West Nile virus, Zika virus, and Japanese encephalitis virus can cause lifelong health effects or even death. Risk for increased spread of mosquito-vectored disease is on the rise. The continued effects of climate change, increasing temperatures away from the equator, and increased encroachment into natural areas for urban development, is opening the door for new infectious diseases spread by mosquitoes. There are many ways to curb the effects that these viral diseases can have on humans, including vaccines or mosquito repellents, and even eliminating mosquito populations is helping to reduce the effects of these important diseases. Sadly, no one method can solve the problem. The methods of dealing with mosquito transmitted disease are likely to be most effective when done in combination. The more countermeasures that attempt to stop the spread of disease, the greater dent in reducing the spread of disease. In this dissertation, we dive into the realm of stopping disease transmission before humans become a factor. If we can limit mosquito infections, then the disease has no way of reaching humans. An approach to controlling mosquito infections could lie within viruses themselves. Aripo virus, an insect-specific virus, is interesting in that it does not affect vertebrates, only mosquitoes. When Aripo virus infects mosquito cells at the same time as deadly viruses, the deadly viruses do not accumulate in the mosquito cells nearly as much.
Within mosquito cells, Aripo virus was able to reduce the levels of West Nile virus, St. Louis encephalitis virus, Japanese encephalitis virus, Zika virus, and Mayaro virus. If the underlying concept of the method of Aripo virus induced exclusion of deadly viruses could be further understood, it could be used to reduce the spread of mosquito-related viral diseases.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/111073 |
| Date | 06 January 2021 |
| Creators | Carver, James A. |
| Contributors | Entomology, Auguste, A. Jonathan, Weger-Lucarelli, James, Eastwood, Gillian |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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