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Updated: May 19, 2026
06:02
Arbovirus Infections As Screening Tools for the Identification of Viral Immunomodulators and Host Antiviral Factors
Published on: September 13, 2018
Eilat virus, a unique alphavirus with host range restricted to insects by RNA replication
Farooq Nasar1, Gustavo Palacios, Rodion V Gorchakov
1Institute for Human Infections and Immunity and Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
Summary
A newly discovered alphavirus, Eilat virus (EILV), infects mosquitoes but not vertebrate cells. This mosquito-specific virus may help researchers understand how arboviruses evolve host range and disease emergence.
Area of Science:
- Virology
- Arthropod-borne viruses
- Molecular biology
Background:
- Most arboviruses, including alphaviruses, infect both arthropods and vertebrates, which is crucial for their natural cycle.
- Some flaviviruses are known to infect mosquitoes but not vertebrates, with mechanisms of host restriction yet to be fully understood.
Purpose of the Study:
- To characterize a novel alphavirus, Eilat virus (EILV), isolated from mosquitoes.
- To investigate the host range and replication capabilities of EILV, particularly its ability to infect vertebrate cells.
Main Methods:
- Phylogenetic analysis to determine EILV's evolutionary relationship to other alphaviruses.
- Electron microscopy to visualize EILV virion structure and budding process.
- Infection assays using various insect and vertebrate cell lines at different temperatures (37 °C and 28 °C) to assess viral and RNA replication.
Main Results:
- Eilat virus (EILV) was phylogenetically placed as a sister to the Western equine encephalitis antigenic complex.
- EILV virions are spherical, 70 nm in diameter, and bud from mosquito cell plasma membranes.
- EILV efficiently infected insect cells but failed to infect mammalian or avian cell lines, with no detectable viral or RNA replication at either 37 °C or 28 °C.
Conclusions:
- Eilat virus (EILV) is a unique, mosquito-specific alphavirus, representing a novel complex within the genus Alphavirus.
- EILV appears to have lost the ability to infect vertebrate cells during its evolution.
- Further studies using reverse genetics on EILV could reveal determinants of alphavirus host range and disease emergence.
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