Bio:
I am a graduate student from Singapore, and my work focuses on the
Aedes aegypti
cell line immune responses to dengue virus. I am interested
in host-pathogen interactions such as virus mediated immune suppression, and
would like to explore these mechanisms in both insect and vertebrate cells.
Current research:
Use of cell line system
We have established an Ae. aegypti cell line system to further
dissect mosquito immune responses to dengue virus (DENV). The use of the
Aag2 cell line avoids the structural complexity of whole mosquitoes,
provides a more sensitive method of detecting changes in gene regulation,
and is easier to scale up for semi-high throughput assays such as RNAi
screens.
Immune suppressive activity of DENV in the cell line
In order to study the effect of DENV infection on insect cell
immune gene expression, a microarray analysis was carried out on live and
heat-inactivated (HI) DENV infected Aag2 cells.
 Fig
1: Live DENV up-regulates half as many immune genes as heat
inactivated (HI) DENV, while down-regulating twice as many immune genes.
Significantly regulated genes are shown here arranged by functional class;
immune genes are shown in red.
Fig 2: Many immune genes are oppositely regulated in
live DENV-infected cells and Cactus-silenced (Rel1 activated) mosquitoes.
Cactus silencing simulates Toll pathway activation and results in the
production of numerous anti-microbial effector molecules. Immune genes
regulated by live DENV in the Aag2 cell line and by Cactus silencing in
whole mosquitoes were clustered. Green indicates downregulation; red
indicates upregulation.
Future directions
We are currently studying this immune suppression in more detail
to determine which immune pathways the virus is acting on, and are
particularly interested to determine if known mechanisms of DENV immune
suppression in mammalian cells are also at work in invertebrate cells.
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