The Arbovirus Immunology research area was established recently at the Institute to focus on the innate and adaptive immune response and pathogenesis of arthropod-borne virus (arbovirus) infections in their mammalian hosts. Arboviruses are transmitted between vertebrate hosts by arthropod vectors such as ticks, mosquitoes and biting midges and inoculated into the skin together with arthropod saliva. This saliva contains a vast range of pharmacologically active molecules that influence virus infectivity, dissemination and, ultimately, virulence.
Therefore our research is specifically targeted at the unique interaction between the virus, the arthropod saliva and the mammalian immune response (systemic and of the skin) following blood feeding and infection. Understanding the immune response of mammalian hosts to arboviruses and vector saliva is vital in fully understanding how these viruses cause disease and may eventually lead to novel methods of control.
Our aim is to investigate the complex interactions between vertebrate host, arthropod vector and arbovirus. This helps us to understand the vertebrate host’s immune responses to arboviruses in the context of inflammatory response to vector blood-feeding and saliva inoculation. Identifying immune response components facilitating protection as well as underlying mechanisms which contribute to disease exacerbation, will lead to better prevention of arbovirus infections as well as potential treatment options. Specific current objectives include:
- Analysing the innate and adaptive immune response of mammalian hosts to Culicoides (biting midges) saliva proteins and the subsequent effects on virus infectivity and dissemination
- Determine the role of Culicoides saliva proteins for the transmission, infectivity and dissemination of important arboviruses of livestock (e.g. bluetongue virus (BTV) and Schmallenberg viruses (SBV)).
The group is currently studying the cellular responses and susceptibility of ruminant immune cells and skin cells following infection with BTV and SBV in the presence and absence of Culicoides saliva proteins.
The innate and systemic immune response of ruminants towards Culicoides saliva proteins is further investigated to identify immunogenic saliva proteins and their specific role in virus transmission and hypersensitivity induction.
Furthermore, the enzymatic activity of Culicoides saliva and potential additional functions of saliva proteins is explored.
Analysing the immune response of mammalian hosts to viruses transmitted by blood-feeding insects is complicated by the fact that these pathogens are inoculated into the hosts’ skin alongside insect saliva. Bioactive molecules present in insect vector saliva trigger inflammatory responses in mammalian skin and these have a major influence on arbovirus dissemination, cellular infectivity and virulence.
Our work currently focuses on Culicoides transmitted arboviruses such as BTV, which are a major threat to the livestock farming sector. We have previously demonstrated that Culicoides saliva can directly modify the BTV particle and its infectivity. We are currently investigating the immune response mechanism induced by Culicoides saliva in mammalian hosts to further elucidate its influence on viral infectivity and dissemination as well as its general immune-modulatory potential.
Understanding innate immune responses to arboviruses in natural host systems in the context of insect saliva co-inoculation will allow better transmission prevention not only for BTV but also contribute to the wider understanding of arbovirus transmission relevant to human health.