Immune-related transcripts, microbiota and vector competence differ in dengue-2 virus-infected geographically distinct Aedes aegypti populations

Abstract

Background Vector competence in Aedes aegypti is influenced by various factors. Crucial new control methods can be developed by recognizing which factors affect virus and mosquito interactions. Methods In the present study we used three geographically distinct Ae. aegypti populations and compared their susceptibility to infection by dengue virus serotype 2 (DENV-2). To identify any differences among the three mosquito populations, we evaluated expression levels of immune-related genes and assessed the presence of microbiota that might contribute to the uniqueness in their vector competence. Results Based on the results from the DENV-2 competence study, we categorized the three geographically distinct Ae. aegypti populations into a refractory population (Vilas do Atlântico), a susceptible population (Vero) and a susceptible but low transmission population (California). The immune-related transcripts were highly expressed in the California population but not in the refractory population. However, the Rel-1 gene was upregulated in the Vilas do Atlântico population following ingestion of a non-infectious blood meal, suggesting the gene’s involvement in non-viral responses, such as response to microbiota. Screening of the bacteria, fungi and flaviviruses revealed differences between populations, and any of these could be one of the factors that interfere with the vector competence. Conclusions The results reveal potential factors that might impact the virus and mosquito interaction, as well as influence the Ae. aegypti refractory phenotype. Graphical Abstract

Artificial Feeding Systems for Vector-Borne Disease Studies

“…In studies focusing on pathogen acquisition, artificial feeding systems have been instrumental in investigating the complex mechanisms of vector–pathogen interactions. They provide a means to explore vector susceptibility factors, including immunological responses, environmental influences, and vector genetics, all of which impact the vector’s ability to acquire and transmit pathogens [ 180 , 181 ]. Artificial feeding systems also enable the precise control of vector infection status, facilitating the evaluation of various factors’ effects on transmission rates [ 182 ].…”