Transcriptome Analysis of Aedes aegypti Aag2 Cells in Response to Dengue Virus-2 Infection

Abstract

Background: Dengue virus (DENV) is a flavivirus transmitted by mosquitoes that is prevalent in tropical and subtropical countries and has four serotypes (DENV1-4). Aedes aegypti, as the main transmission vector of DENV, exhibits strong infectivity and transmission. With the aim of obtaining a better understanding of the Ae. aegypti-DENV interaction, the transcriptome changes in DENV-2-infected Aag2 cells were studied to describe the immune responses of mosquitoes using the Ae. aegypti Aag2 cell line as a model.Methods: RNAseq technology was used to sequence the transcripts of the Ae. aegypti Aag2 cell line before and after infection with DENV-2. A bioinformatics analysis was then performed to assess the biological functions of the differentially expressed genes, and the sequencing data were verified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR).Results: The transcriptome analysis generated 8866 unigenes that were found in both groups, 225 unigenes that were only found in the infection group, and 683 unigenes that only existed in the control group. A total of 1199 differentially expressed genes, including 1014 upregulated and 185 downregulated genes, were identified. The bioinformatics analysis showed that the differentially expressed genes were mainly involved in the longevity regulating pathway, circadian rhythm, DNA replication, and peroxisome, purine, pyrimidine, and drug metabolism. The qRT-PCR verification results showed the same trend, which confirmed that the expression of the differentially expressed genes had changed and that the transcriptome sequencing data were reliable.Conclusions: This study investigated the changes in the transcriptome levels in the DENV-2-infected Ae. aegypti Aag2 cell line, which provides a faster and effective method for discovering genes related to Ae. aegypti pathogen susceptibility. The findings provide basic data and directions for further research on the complex mechanism underlying host-pathogen interactions.

Controlling arbovirus infection: high-throughput transcriptome and proteome insights

“…It is worth noting, however, that different strains are used across studies, with the Rockefeller strain being the most used. Transcriptomic data is also accessible for A. albopictus , C. pipiens , and for the three mosquito cell lines Aag2 ( Li et al, 2020 ), U4.4 ( Öhlund et al, 2022 ), Hsu ( Paradkar et al, 2015 ) derived from A. aegypti , A. albopictus , and C. quinquefasciatus , respectively. Among the studied viruses, DENV-2 infection was the most extensively examined, followed by ZIKV and WNV.…”

Revisiting dengue virus-mosquito interactions: molecular insights into viral fitness

“…This includes alterations in the expression of genes involved in transport, metabolic processes, ion binding and peptidase activity. Similarly, in DENV-infected Aag2 and C6/36 cells, 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 were observed [28, 30].…”

“…Downregulation of several genes related to the Toll pathway was observed at different time-points during DENV infection in Ae. aegypti-derived Aag2 cells [28,29], Ae. albopictus-derived C6/36 cells [30], and Ae.…”

“…In contrast to the Toll and JAK-STAT pathways, the roles of the IMD pathway in controlling DENV infection remain elusive. The IMD pathway was shown to be inhibited upon DENV infection in some studies, suggesting its involvement in anti-DENV defence [28,30]. In contrast, another study showed that while knockdown of the signal transduction adaptor protein IMD of the IMD pathway increased viral load in the midgut of DENV-infected Ae.…”