Small non-coding RNAs, in particular microRNAs, play significant roles in regulation of various
biological processes and their dysregulation leads to disorders. Recently, their role in cell-cell and
cross-species communications has also been revealed. Research has shown that a subset of stable
microRNAs is present in high abundance in blood which may affect other tissues or microorganisms
exposed to them. In this innovative project, we aim to explore the potential role of human blood
circulating microRNAs taken up by mosquitoes in regulating expression of genes in the mosquitoes
and their effect on replication of viruses that they transmit. As a model, we will use Aedes aegypti, a
notorious vector of several arboviruses, and dengue virus as the second most important vector-borne
pathogen. Our preliminary data shows that blood-derived microRNAs are stable in mosquitoes for
hours, successfully pass the mosquito midgut into other tissues in the body cavity and importantly occur
in biologically abundant numbers. In addition, our preliminary results show that at least one of the
human blood microRNAs alter mosquito genes that are involved in mosquito immunity and
We hypothesize that (i) circulating human blood-derived miRNAs obtained through blood feeding are
absorbed through the mosquito midgut and translocated into mosquito tissues, and (ii) the exchanged
miRNAs play roles in mosquito biology and affect replication of viruses they transmit.
To address these hypotheses, we aim 1) to analyze human blood miRNAs in Ae. aegypti biology, 2)
to identify the target genes of blood miRNAs in Ae. aegypti and their effect on mosquito biology, and
3) determine the effect of inhibition of human blood miRNAs on mosquito-virus interactions.
We anticipate that the outcomes will advance our understanding of the molecular events following
blood uptake by mosquitoes, and build-up of essential knowledge in identification of potential target
molecules for interfering in mosquito reproduction or virus replication.