Inhibition of defensin A and cecropin A responses to dengue virus 1 infection in Aedes aegypti

• Published in: Biomédica
• Main Authors: Yda Méndez, César Pacheco, Flor Herrera
• Format: Article in Journal/Newspaper
• Language: English; Spanish
• Published: Instituto Nacional de Salud 2021
• Subjects: aedes aegypti; dengue virus; alpha-defensins; cecropins; escherichia coli; Medicine; R; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.7705/biomedica.5491; https://doaj.org/article/4c6103ac34704599bfa60378dd46ff58

Introduction: It is essential to determine the interactions between viruses and mosquitoes to diminish dengue viral transmission. These interactions constitute a very complex system of highly regulated pathways known as the innate immune system of the mosquito, which produces antimicrobial peptides that act as effector molecules against bacterial and fungal infections. There is less information about such effects on virus infections. Objective: To determine the expression of two antimicrobial peptide genes, defensin A and cecropin A, in Aedes aegypti mosquitoes infected with DENV-1. Materials and methods: We used the F1 generation of mosquitoes orally infected with DENV-1 and real-time PCR analysis to determine whether the defensin A and cecropin A genes played a role in controlling DENV-1 replication in Ae. aegypti. As a reference, we conducted similar experiments with the bacteria Escherichia coli. Results: Basal levels of defensin A and cecropin A mRNA were expressed in uninfected mosquitoes at different times post-blood feeding. The infected mosquitoes experienced reduced expression of these mRNA by at least eightfold when compared to uninfected control mosquitoes at all times post-infection. In contrast with the behavior of DENV-1, results showed that bacterial infection produced up-regulation of defensin and cecropin genes; however, the induction of transcripts occurred at later times (15 days). Conclusion: DENV-1 virus inhibited the expression of defensin A and cecropin A genes in a wild Ae. aegypti population from Venezuela.