The entomopathogenic fungus Beauveria bassiana activate toll and JAK-STAT pathway-controlled effector genes and anti-dengue activity in Aedes aegypti

Here we investigated the effect of Beauveria bassiana infection on the survival of Aedes aegypti mosquitoes and the modulation of their susceptibility to dengue virus infection. Application of B. bassiana caused a reduction in the life span of A. aegypti and hindered dengue virus replication in the mosquito midgut. Fungus infection induced the expression a variety anti-microbial and dengue virus restriction factor genes. Transient reverse genetic analyses showed that the JAK-STAT pathway is implicated anti-fungal defense of Aedes mosquitoes. Our data suggest that this B. bassiana-mediated anti-dengue activity is likely to be at least partly indirectly mediated through the activation of the mosquito’s anti-dengue Toll and JAK-STAT pathways.

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► The fungus Beauveria bassiana can significantly shorten the life span of Ae. aegypti mosquitoes even at low exposure dosages.
► We show for the first time that fungal exposure can significantly suppress the dengue virus infection in mosquitoes.
► We provide evidence that Toll and JAK-STAT pathway effector genes are up-regulated upon fungal challenge.
► We show that the JAK-STAT pathway is implicated in anti-fungal defense.