Table 1.

Identification of relevant host factors and cellular processes during DENV infection in its mosquito vectors

Study	Methods	Findings	References
Transcriptomic studies
Identification of the mosquito innate immune system as a part of anti-DENV defences	Microarray Digital gene expression RNAi-based gene knockdown Microarray RNAi-based gene knockdown Microarray RNA-sequencing RT-PCR RNA sequencing RT-PCR Northern blot Immunofluorescence Transgenic Ae. aegypti RNAi-based gene knockdown	Upregulation of genes related to the Toll, JAK-STAT and IMD pathways. The signalling components of the Toll (MyD88) and JAK-STAT (Dome and JAK/Hop) pathways are HRFs while the negative regulators of the Toll (Cactus) and JAK-STAT (PIAS) pathways are HDFs. A conserved function in anti-DENV defence of the Toll and JAK-STAT pathways across different Ae. aegypti strains. Downregulation of genes related to the Toll and IMD pathways following DENV infection. The ability of DENV sfRNA and sNS1 to inhibit the Toll and JAK-STAT pathways, respectively. The presence of the siRNA pathway and its importance in anti-DENV defence in Ae. aegypti.	[23–25, 31] [25–27, 32] [26, 27, 32] [30] [26, 28, 29], [19, 33] [37–40]
Identification of other relevant cellular processes during virus infection through comparative transcriptomic studies	Microarray Microarray RNA-sequencing	A potential role of differentially transcriptomic changes underlying vector competence of Ae. aegypti. - DENV-susceptible Ae. aegypti strain: upregulation of genes involved in the proteasome, mRNA surveillance and protein processing in the ER. DENV-refractory Ae. aegypti strain: upregulation of genes involved in the Wnt signalling pathway, the glycolysis pathway and glycan biosynthesis. A potentially conserved transcriptomic signature of flavivirus infection. - Alteration in the expression of genes involved in metabolic processes, peptidase activity, ion binding and transport during DENV, WNV and YFV infection. A consistent upregulation of genes involved in starch and sucrose metabolism, pyrimidine metabolism and drug metabolism, and downregulation of genes involved in RNA transport, purine metabolism, drug metabolism, folate biosynthesis, and valine, leucine and isoleucine degradation in DENV-infected Aag2 and C6/36 cells.	[41] [42] [30] [28],
Proteomic studies
Proteomic changes during DENV infection	2D-DIGE MALDI-TOF MS 2D-DIGE MALDI-TOF/TOF MS 2DE LC-MS/MS	Upregulation of proteins involved in the glycolysis pathway and the cellular stress response in C6/36 cells. Increased production of proteins involved in carbohydrate and lipid metabolism as well as the production of reactive oxygen species (ROSs) in Ae. aegypti midguts. Alteration in the expression of proteins; in particular proteins with anti-hemostatic and pain inhibitory properties in Ae. aegypti salivary glands.	[43] [44] [46]
Identification of potential cellular receptors	VOPBA Mass spectrometry VOPBA Mass spectrometry Co-purification Mass spectrometry	With the use of Ae. aegypti midgut homogenates and C6/36 cell lysates, cadherin, enolase, beta-adrenergic receptor kinase (beta-ARK) and translation elongation factor EF-1 alpha/Tu were identified. With the use of the membrane fractions of A7 cells, C6/36 cells and Ae. aegypti midguts, actin, orisis, vav-1, prohibitin, ATP synthase β subunit, tubulin β chain, and 70-kD heat shock cognate protein (HSC70) were identified. With the use of C6/36 cell lysates, HSC70, 78 kDa glucose-regulated protein (GRP78 or BiP), 70 kDa heat shock protein (HSP70) and 40 kDa protein with homology to protein disulfide isomerase (PDI) were identified.	[50] [51] [52]
Identification of DENV-mosquito protein interactions	Tandem affinity purification LC-MS/MS RNAi-based gene knockdown Affinity purification LC-MS/MS Pharmacological inhibition	18 mosquito proteins as potential interacting partners of DENV and WNV proteins. Actin, myosin, myosin light chain kinase and PI3-kinase are DENV and WNV HDFs. 28 host proteins both humans and mosquitoes as interacting partners of DENV and ZIKV proteins. SEC61 is a shared DENV and ZIKV HDF in both mammalian and mosquito cells.	[53]. [11]
Metabolomic studies
Lipidomic changes during DENV infection	LC-MS LC-HRMS RNAi-based gene knockdown	Upregulation of lipid anabolism and catabolism. Enrichment of lipids that can modify the physical properties of membranes. Increased production of membrane phospholipids which are required to modify mosquito membrane structures to support DENV replication.	[54] [56] [57],
Potential importance of lipid modulation during DENV infection	LC-MS RNAi-based gene knockdown Microarray RNAi-based gene knockdown	Identification of lipid modulation as a molecular mechanism underlying Wolbachia -mediated DENV blocking in Ae. aegypti. Upregulation of genes encoding lipid-binding proteins – the myeloid differentiation 2-related lipid recognition protein (ML) and the Niemann Pick-type C1 (NPC1) family members in Ae. aegypti, and silencing of those gene family members restricted DENV infection in Ae. aegypti midgut.	[58] [24, 25, 59]
Computational studies
Establishment of DENV-mosquito interaction networks	Computational approach based on available data from genome-wide RNAi screens, transcriptomic studies and physical protein-protein interactions Computational approach based on structural similarity of DENV and Ae. aegypti proteins	714 DENV-Ae. aegypti interactions with Ae. aegypti proteins involved in transport, immunity, metabolism and replication/transcription/translation being the most enriched. 176 DENV-Ae. aegypti interactions with Ae. aegypti proteins involved in RNA processing and regulation of stress response being the most enriched.	[60] [61]

2D-DIGE, two-dimensional differential in-gel electrophoresis; 2DE, two-dimensional gel electrophoresis; LC-HRMS, liquid chromatography-high resolution mass spectrometry; LC-MS, liquid chromatography-mass spectrometry; LC-MS/MS, liquid chromatography-tandem mass spectrometry; MALDI-TOF MS, matrix assisted laser desorption ionisation time-of-flight mass spectrometry; MALDI-TOF/TOF MS, matrix assisted laser desorption ionisation time-of-flight/time-of-flight mass spectrometry; RNAi, RNA interference; RT-PCR, real-time polymerase chain reaction; VOPBA, virus overlay protein binding assay.