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Updated: Jul 5, 2026
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Arbovirus Infections As Screening Tools for the Identification of Viral Immunomodulators and Host Antiviral Factors
Published on: September 13, 2018
Arbovirus evolution in vivo is constrained by host alternation.
Lark L Coffey1, Nikos Vasilakis, Aaron C Brault
1Department of Pathology and Center for Tropical Diseases, University of Texas Medical Branch, Galveston, TX 77555, USA.
Summary
Arthropod-borne viruses (arboviruses) may evolve slower due to alternating hosts. Specializing in one host, like mosquitoes or vertebrates, accelerates adaptation, potentially impacting epidemic emergence frequency.
Area of Science:
- Virology
- Evolutionary Biology
- Epidemiology
Background:
- RNA virus plasticity drives host range expansion and epidemics.
- Evolutionary constraints on arthropod-borne virus (arbovirus) cross-species transmission are not well understood.
- Arboviruses may face fitness trade-offs when adapting to distinct mosquito and vertebrate hosts.
Purpose of the Study:
- To investigate the impact of host alternation on arbovirus adaptation and evolution.
- To test the hypothesis that specialization in a single host accelerates arbovirus adaptation.
- To evaluate arboviral emergence potential in relation to host range.
Main Methods:
- Utilized an in vivo model system with Venezuelan equine encephalitis virus (VEEV), an emerging alphavirus.
- Serially passaged VEEV in mosquitoes to assess adaptation to arthropod hosts.
- Developed vertebrate-specialized VEEV strains to evaluate adaptation to vertebrate hosts.
- Compared fitness gains in single-host specialized strains versus alternately passaged strains.
Main Results:
- Serial passage in mosquitoes enhanced VEEV infectivity in arthropod hosts.
- Vertebrate-specialized VEEV strains demonstrated increased viremia in vertebrate hosts.
- Alternately passaged VEEV showed no significant fitness improvements in either host.
- Host specialization accelerated arbovirus adaptation, while host alternation did not.
Conclusions:
- Arbovirus adaptation and evolution are constrained by their obligate alternation between hosts.
- Specialization in a single host (mosquito or vertebrate) promotes viral fitness.
- Arboviral emergence through host range expansion may be less frequent than for viruses with single-host replication cycles.
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