what are bunyaviruses?
Bunyaviruses are the largest group of viruses with an RNA genome. They have a vast geographic presence and can infect a range of hosts.
The bunyaviruses we study are primarily arboviruses (meaning they require insects for transmission) and can cause disease in humans and animals. Many of these viruses also have zoonotic potential (meaning they can spread from animals to humans).
Batai and Bunyamwera viruses are mosquito transmitted and are primarily found in Africa.
Dabie bandavirus is prevalent in South East Asia and is spread via ticks.
Heartland virus (or Heartland bandavirus) is also spread by ticks and most human infections occur in the Southern and Midwestern parts of the US.
Oropouche virus is midge transmitted and is found in Central and South America.
These bunyaviruses cause a range of mild to severe diseases in humans and animals.
Some of the viruses we study you probably never knew existed!
Batai virus, Bunyamwera virus, Dabie bandavirus (previously called SFTSV), Heartland bandavirus and Oropouche virus.
The bunyavirus genome is made up of three negative polarity RNA segments. When two or more closely-related bunyaviruses infect the same cells in the same host they can exchange these segments with each other. This process is called reassortment and it is a major driver of segmented virus evolution.
Reassortment is a way influenza viruses evolve as well, and has been the cause of several of the pandemic strains.
Our knowledge of reassortment in bunyaviruses is limited compared to what we know about influenza viruses. This is a not good news as reassortment has given rise to some nasty bunyaviruses in the past.
Using imaging and molecular interactions techniques, as well as mouse models our lab is trying to understand bunyavirus reassortment at the molecular level. We also hope to understand what evolutionary pressures play a role in the fitness of a new reassortment virus (called a reassortant).
Reassortment
Oropouche virus inspired the Tilston’s lab’s bunyavirus journey. This virus gets its name after a river in Trinidad where it was first identified.
Sloths and marmosets are the likely animal reservoirs (meaning the virus is maintained in nature in these animals).
Oropouche virus is a major public health threat in Central and South America. Since the early 60s over half a million infections have been documented. However, with the lack of an adequate diagnostic system the actual infections are likely much higher. To add to this, we now know there are three Oropouche virus reassortants co-circulating in these areas.
Oropouche virus
Our goal is to better understand the pathogenesis of Oropouche virus, and how natural reassortment impacts Oropouche virus virulence.
The interactions that go on between a virus and the host cell are complex. Our goal is to define some of these interactions, specifically the ones that go on with viral proteins that are known to be antagonistic to the host’s immune system. By defining these interactions and how they change in the reassortants we hope to better understand disease outcome.
virus-host interactions
Related publications
Tilston-Lunel NL, Shi X, Elliott RM, Acrani GO. The Potential for Reassortment between Oropouche and Schmallenberg Orthobunyaviruses. Viruses. 2017 Aug 11;9(8) PubMed Central PMCID: PMC5580477.
Tilston-Lunel NL, Acrani GO, Randall RE, Elliott RM. Generation of Recombinant Oropouche Viruses Lacking the Nonstructural Protein NSm or NSs. J Virol. 2015 Dec 23;90(5):2616-27. PubMed Central PMCID: PMC4810690.
Biosafety
A lot of what we do requires high containment. We have the necessary approvals and training to safely work at A/BSL-3.
