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Updated: Sep 20, 2025
Experimental Viral Infection in Adult Mosquitoes by Oral Feeding and Microinjection
Published on: July 28, 2022
Mosquito saliva enhances virus infection through sialokinin-dependent vascular leakage
Daniella A Lefteri1, Steven R Bryden1, Marieke Pingen1
1Virus Host Interaction Team, Leeds Institute of Medical Research, School of Medicine, Faculty of Medicine and Health, University of Leeds, Leeds, LS9 7TF, United Kingdom.
Abstract:
Viruses transmitted by Aedes mosquitoes are an increasingly important global cause of disease. Defining common determinants of host susceptibility to this large group of heterogenous pathogens is key for informing the rational design of panviral medicines. Infection of the vertebrate host with these viruses is enhanced by mosquito saliva, a complex mixture of salivary-gland-derived factors and microbiota. We show that the enhancement of infection by saliva was dependent on vascular function and was independent of most antisaliva immune responses, including salivary microbiota. Instead, the Aedes gene product sialokinin mediated the enhancement of virus infection through a rapid reduction in endothelial barrier integrity. Sialokinin is unique within the insect world as having a vertebrate-like tachykinin sequence and is absent from Anopheles mosquitoes, which are incompetent for most arthropod-borne viruses, whose saliva was not proviral and did not induce similar vascular permeability. Therapeutic strategies targeting sialokinin have the potential to limit disease severity following infection with Aedes-mosquito-borne viruses.
Insights
Mosquito saliva enhances viral infections by impacting vascular function. A specific protein, sialokinin, reduces endothelial barrier integrity, increasing disease risk from Aedes-borne viruses.
Area of Science:
- Virology
- Immunology
- Entomology
Background:
- Aedes mosquitoes transmit numerous viruses globally, posing a significant public health threat.
- Understanding host susceptibility is crucial for developing broad-acting antiviral therapies.
- Mosquito saliva enhances pathogen transmission, but the mechanisms are not fully understood.
Purpose of the Study:
- To identify the salivary factors responsible for enhancing Aedes-borne virus infections.
- To elucidate the mechanism by which mosquito saliva increases host susceptibility.
- To explore potential therapeutic targets for Aedes-borne viral diseases.
Main Methods:
- Investigated the role of vascular function and immune responses in saliva-mediated infection enhancement.
- Identified the Aedes gene product sialokinin as a key mediator of infection enhancement.
- Compared the effects of Aedes saliva with Anopheles saliva on vascular permeability.
Main Results:
- Saliva-enhanced infection was dependent on vascular function and independent of anti-saliva immunity.
- Aedes sialokinin rapidly reduced endothelial barrier integrity, facilitating virus entry.
- Sialokinin's unique vertebrate-like sequence and absence in Anopheles mosquitoes correlate with differential virus transmission competence.
Conclusions:
- Aedes sialokinin is a critical factor in enhancing virus infection by compromising vascular integrity.
- Targeting sialokinin offers a potential therapeutic strategy to mitigate Aedes-borne viral diseases.
- This finding provides a novel target for panviral medicines against Aedes-transmitted pathogens.
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