Differential Protein Modulation in Midguts of Aedes aegypti Infected with Chikungunya and Dengue 2 Viruses

Abstract

BackgroundArthropod borne virus infections cause several emerging and resurgent infectious diseases. Among the diseases caused by arboviruses, dengue and chikungunya are responsible for a high rate of severe human diseases worldwide. The midgut of mosquitoes is the first barrier for pathogen transmission and is a target organ where arboviruses must replicate prior to infecting other organs. A proteomic approach was undertaken to characterize the key virus/vector interactions and host protein modifications that happen in the midgut for viral transmission to eventually take place.Methodology and Principal FindingsUsing a proteomics differential approach with two-Dimensional Differential in-Gel Electrophoresis (2D-DIGE), we defined the protein modulations in the midgut of Aedes aegypti that were triggered seven days after an oral infection (7 DPI) with dengue 2 (DENV-2) and chikungunya (CHIKV) viruses. Gel profile comparisons showed that the level of 18 proteins was modulated by DENV-2 only and 12 proteins were modulated by CHIKV only. Twenty proteins were regulated by both viruses in either similar or different ways. Both viruses caused an increase of proteins involved in the generation of reactive oxygen species, energy production, and carbohydrate and lipid metabolism. Midgut infection by DENV-2 and CHIKV triggered an antioxidant response. CHIKV infection produced an increase of proteins involved in detoxification.Conclusion/SignificanceOur study constitutes the first analysis of the protein response of Aedes aegypti's midgut infected with viruses belonging to different families. It shows that the differentially regulated proteins in response to viral infection include structural, redox, regulatory proteins, and enzymes for several metabolic pathways. Some of these proteins like antioxidant are probably involved in cell protection. On the other hand, we propose that the modulation of other proteins like transferrin, hsp60 and alpha glucosidase, may favour virus survival, replication and transmission, suggesting a subversion of the insect cell metabolism by the arboviruses.

Insect transferrins: Multifunctional proteins

“…The promoter region of D. melanogaster [30,80], P. xylostella [38], B. mori [70,110] and A. aegypti [19,27,29,37,111] Tsf1 genes is rich in putative NF-B binding sites supporting the hypothesis that Tsf1 has a role in innate immunity in these animals [2,18].A. aegypti Aag2 cells and A. albopictus (Asian tiger mosquito) C7-10 cells secrete Tsf1 when challenged with heat-killed bacteria [29].…”

“…CqTsf1 is upregulated in C. quinquefasciatus infected with W. bancrofti [27]. In contrast, in A. aegypti, infection with the Dengue virus up-regulates salivary gland Tsf1 [115], but the protein is down-regulated [111]. This was also the case for infection of Aedes with Chikungunya virus [111].…”

Protein-protein interactions between A. aegypti midgut and dengue virus 2: two-hybrid screens using the midgut cDNA library

“…This finding may be linked to the ability of RNA viruses (including DENV) to regulate its host cell gene expression profiles [44].…”

Proteome Analysis of Cry4Ba Toxin-interacting Aedes aegypti Lipid Rafts using geLC–MS/MS

“…Proteomic analyses of insect midguts have characterized either total BBMV proteomes 51, 52 or a proteome subset such as Bt toxin binding proteins 28, 53, 54 . Our geLC-MS/MS analysis of the DRM sub-proteome identified lipid raft marker proteins flotillin-1, flotillin-2, APN and ALP and many other proteins reported in similar analyses of DRMs 55–59 .…”