Université de Strasbourg

Fellows Seminar - The molecular basis of natural antiviral resistance in mosquitoes and the implications for transmission to humans

December 2, 2021
From 15:30 until 17:00
Strasbourg (FR)

Image: Pixabay

The molecular basis of natural antiviral resistance against Dengue and Zika viruses in Aedes aegypti mosquitoes

By João Marques, 2019 Fellow

Viral epidemics have gained increasing attention due to the COVID-19 pandemic, but SARS-CoV-2 is not the only virus threatening humans worldwide. Zika (ZIKV) and Dengue (DENV) are arthropod-borne viruses belonging to the Flaviviridae family that are transmitted by Aedes mosquitoes, especially Aedes aegypti. An estimated 390 million people per year get infected with dengue worldwide, of which about 100 million people get sick from infection each year. Dengue is considered by the World Health Organization to be the most critical mosquito-borne viral disease worldwide. No efficient treatments or vaccines are available against these viruses to date and strategies to contain infection rely mostly on prevention and vector control. To make matters worse, infections by mosquito-borne viruses are increasing rapidly due to climate change and urbanization. In addition, as with COVID-19, it is possible that new mosquito-borne viruses will emerge and cause global pandemics. Therefore, we urgently need more tools to prevent and control the spread of mosquito-borne viruses.

Our laboratory focuses on identifying and characterizing viruses circulating in mosquitoes and understanding factors that affect their transmission to humans. We have recently performed a global surveillance in wild Aedes mosquitoes that led to the identification of several novel viruses. Interestingly, we found that the most abundant of these viruses were insect specific and therefore did not cause infections in humans. However, we identified positive interactions between two of the insect specific viruses, named Phasi-Charoen like virus (PCLV) and Humaita Tubiacanga virus (HTV) with dengue and Zika viruses in wild mosquitoes. In the laboratory, we demonstrate that HTV and PCLV directly affect the ability of Aedes aegypti mosquitoes to transmit dengue and Zika viruses by modulating the expression of pro-viral factors. Our study highlights the complexities of virus transmission by mosquitoes in the wild and provides a basis for novel control strategies.

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