ABSTRACT
Mosquitoes naturally harbor a diverse community of microorganisms that play a crucial role in their biology. Mosquito-microbiota interactions are abundant and complex. They can dramatically alter the mosquito immune response, and impede or enhance a mosquito's ability to transmit medically important arboviral pathogens. Yet critically, given the massive public health impact of arboviral disease, few such interactions have been well characterized. In this review, we describe the current state of knowledge of the role of microorganisms in mosquito biology, how microbial-induced changes to mosquito immunity moderate infection with arboviruses, cases of mosquito-microbial-virus interactions with a defined mechanism, and the molecular interactions that underlie the endosymbiotic bacterium Wolbachia's ability to block virus infection in mosquitoes.
Subject(s)
Host Microbial Interactions/immunology , Microbial Interactions/immunology , Mosquito Vectors , Wolbachia/immunology , Aedes/immunology , Aedes/microbiology , Aedes/virology , Animals , Anopheles/immunology , Anopheles/microbiology , Anopheles/virology , Arbovirus Infections/immunology , Arbovirus Infections/microbiology , Arbovirus Infections/virology , Arboviruses/pathogenicity , Biological Control Agents/immunology , Culex/immunology , Culex/microbiology , Culex/virology , Dengue Virus/pathogenicity , Humans , Immunity, Innate , Microbiota , Mosquito Vectors/immunology , Mosquito Vectors/microbiology , Mosquito Vectors/virology , Virus Diseases/immunology , Virus Diseases/microbiology , Virus Diseases/virologyABSTRACT
In many regions of the world, mosquito-borne viruses pose a growing threat to human health. As an alternative to traditional control measures, the bacterial symbiont Wolbachia has been transferred from Drosophila into the mosquito Aedes aegypti, where it can block the transmission of dengue and Zika viruses. A recent paper has reported large-scale releases of Wolbachia-infected Ae. aegypti in the city of Cairns, Australia. Wolbachia, which is maternally transmitted, invaded and spread through the populations due to a sperm-egg incompatibility called cytoplasmic incompatibility. Over a period of 2 years, a wave of Wolbachia infection slowly spread out from 2 release sites, demonstrating that it will be possible to deploy this strategy in large urban areas. In line with theoretical predictions, Wolbachia infection at a third, smaller release site collapsed due to the immigration of Wolbachia-free mosquitoes from surrounding areas. This remarkable field experiment has both validated theoretical models of Wolbachia population dynamics and demonstrated that this is a viable strategy to modify mosquito populations.
