Dengue virus replicates in mosquito brains with minimal immune response, study finds
A new study using RNA sequencing found that dengue virus productively infects the brains of Aedes aegypti mosquitoes but triggers minimal transcriptional immune response. The research reveals that while blood meals alter thousands of genes including immunity genes, active viral replication in the brain does not increase this response. This finding could help explain how dengue and related viruses persist in mosquitoes and continue to be transmitted to humans.
Researchers used whole-mount immunofluorescence and single-head bulk RNA-sequencing to examine how dengue virus (DENV) infects the brains of Aedes aegypti mosquitoes, the primary vector for dengue, Zika, yellow fever, and chikungunya viruses. The study found that DENV productively replicates in brain cells in a bimodal pattern—individual brains showed either sparse or widespread infection with no intermediate states. While an infectious blood meal altered thousands of genes including 64 immunity genes at 7 days post-feeding, the presence of active viral replication in the head did not increase the transcriptional immune response. Notably, mosquito brains with and without detectable DENV showed minimal transcriptional differences, with no induction of canonical immune effectors. The findings suggest that the mosquito brain tolerates dengue virus replication with minimal transcriptional response, which may have implications for understanding viral persistence and transmission.
What's missing
The study's own limitations and open questions include: whether the minimal transcriptional response reflects post-transcriptional immune mechanisms or other defense pathways not captured by RNA-seq; whether findings generalize to other arboviruses transmitted by Aedes aegypti; and the functional consequences of this tolerance for viral persistence and transmission dynamics.
What different sources said
- bioRxivCenter
Dengue virus infection in Aedes aegypti mosquito brains elicits minimal transcriptional response
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