Arboviruses remain an immense public health threat, causing yearly large epidemics. The overarching aim of this research is to better understand the role of the Aedes aegypti RNA interference (RNAi) pathway in antiviral defense and innate immunity, and to generate knowledge and tools for the development of new methods to control arbovirus transmission. Population replacement of wild-type with genetically modified mosquitoes incapable of pathogen transmission is emerging as a promising complement to other disease control methods. Because Ae. aegypti transmits multiple arbovirus pathogens that are frequently sympatric, it is important for a transgenic mosquito to be resistant to multiple pathogens. The siRNA pathway-mediated antiviral defense system is known to act against a broad range of viruses. However, despite the RNAi pathway's emergence as the major pan-antiviral defense system it remains understudied in mosquitoes. Our research plan is designed to test the overarching hypothesis that the A. aegypti proteins, Dicer-2 (Dcr-2), R2D2 and Argonaute-2 (Ago-2), are key components mediating an RNA silencing response that is broadly protective against arbovirus infections. We will use of siRNA-deficient loss-of-function mutants and transgenic mosquitoes over-expressing Dcr-2, Ago-2 and R2D2 that will be generated in Aim 1. With these genetic tools we will clarify the temporal and spatial specificity of the antiviral response in Aim 2, and investigate possible inter-tissue signaling and regulation of vertical transmission in Aim 3.
In Aim 4 we will address interactions between the RNAi pathway and other innate immunity defense systems. This project utilizes the complementary expertise of Drs Dimopoulos and Myles with the arbovirus infection systems, mosquito transgenesis, mosquito innate immunity and RNAi/small RNA biology. Our proposed project will also generate powerful tools for studying other aspects of the RNAi pathway in Ae. aegypti biology.

Public Health Relevance

Aedes mosquitoes are the primary vectors of the arboviral human pathogens, and the RNA interference pathway is a major pan-antiviral defense system. This proposal will dissect the function of the RNAi pathway in antiviral defense, and assess its suitability for the development of disease control strategies using transgenic mosquitoes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI141532-02
Application #
9827528
Study Section
Vector Biology Study Section (VB)
Program Officer
Costero-Saint Denis, Adriana
Project Start
2018-11-20
Project End
2023-10-31
Budget Start
2019-11-01
Budget End
2020-10-31
Support Year
2
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Microbiology/Immun/Virology
Type
Schools of Public Health
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21205