Activation of innate immunity selectively compromises mitochondrial complex I, proline oxidation, and flight activity in the major arbovirus vector Aedes aegypti.

Aedes aegypti females are natural vectors of important arboviruses such as dengue, zika, and yellow fever. Mosquitoes activate innate immune response signaling pathways upon infection, as a resistance mechanism to fight pathogens and limit their propagation. Despite the beneficial effects of immune activation for insect vectors, phenotypic costs ultimately affect their fitness.

The Aedes aegypti peritrophic matrix controls arbovirus vector competence through HPx1, a heme-induced peroxidase.

Aedes aegypti mosquitoes are the main vectors of arboviruses. The peritrophic matrix (PM) is an extracellular layer that surrounds the blood bolus. It acts as an immune barrier that prevents direct contact of bacteria with midgut epithelial cells during blood digestion.

Hemocyte differentiation to the megacyte lineage enhances mosquito immunity against .

Activation of signaling in by silencing , a suppressor of this pathway, enhances local release of hemocyte-derived microvesicles (HdMv), promoting activation of the mosquito complement-like system, which eliminates ookinetes. We uncovered the mechanism of this immune enhancement. silencing triggers a -mediated differentiation of granulocytes to the megacyte lineage, a new subpopulation of giant cells, resulting in a dramatic increase in the proportion of circulating megacytes.

Double peroxidase and histone acetyltransferase AgTip60 maintain innate immune memory in primed mosquitoes.

Immune priming in is mediated by the systemic release of a hemocyte differentiation factor (HDF), a complex of lipoxin A bound to Evokin, a lipid carrier. HDF increases the proportion of circulating granulocytes and enhances mosquito cellular immunity. Here, we show that Evokin is present in hemocytes and fat-body cells, and messenger RNA (mRNA) expression increases significantly after immune priming.

Morphological Characterization of the Antennal Sensilla of the Afrotropical Sand Fly, Phlebotomus duboscqi (Diptera: Psychodidae).

We investigated by scanning electron microscopy the morphology, distribution, and abundance of antennal sensilla of females Phlebotomus duboscqi sand fly, an important vector of zoonotic cutaneous leishmaniasis at Afrotropical region. Thirteen well-differentiated sensilla were identified, among six types of cuticular sensilla. The probable function of these sensillary types is discussed in relation to their external structure and distribution.

Prostaglandins regulate humoral immune responses in Aedes aegypti.

Prostaglandins (PGs) are immuno-active lipids that mediate the immune response in invertebrates and vertebrates. In insects, PGs play a role on different physiological processes such as reproduction, ion transport and regulation of cellular immunity. However, it is unclear whether PGs play a role in invertebrate's humoral immunity, and, if so, which immune signaling pathways would be modulated by PGs.

Mosquito cellular immunity at single-cell resolution.

Hemocytes limit the capacity of mosquitoes to transmit human pathogens. Here we profile the transcriptomes of 8506 hemocytes of and mosquito vectors. Our data reveal the functional diversity of hemocytes, with different subtypes of granulocytes expressing distinct and evolutionarily conserved subsets of effector genes.

Ultrastructure of the Antennae and Sensilla of Nyssomyia intermedia (Diptera: Psychodidae), Vector of American Cutaneous Leishmaniasis.

The antennal sensilla and the antenna of females Nyssomyia intermedia, one of the main vectors of American cutaneous leishmaniasis, were studied by scanning electron microscopy. The main goal was to characterize the quantity, typology, and topography of the sensilla with particular attention to the olfactory types. The insects were captured in the city of Corte de Pedra, State of Bahia, Brazil, by CDC-type light traps and raised in a laboratory as a new colony.

A mosquito juvenile hormone binding protein (mJHBP) regulates the activation of innate immune defenses and hemocyte development.

Insects rely on the innate immune system for defense against pathogens, some aspects of which are under hormonal control. Here we provide direct experimental evidence showing that the juvenile hormone-binding protein (mJHBP) of Aedes aegypti is required for the regulation of innate immune responses and the development of mosquito blood cells (hemocytes). Using an mJHBP-deficient mosquito line generated by means of CRISPR-Cas9 gene editing technology we uncovered a mutant phenotype characterized by immunosuppression at the humoral and cellular levels, which profoundly affected susceptibility to bacterial infection.

Mosquito Midgut Prostaglandin Release Establishes Systemic Immune Priming.

Anopheles gambiae mosquitoes that have been infected with Plasmodium mount a more effective immune response to a subsequent infection. Priming is established when Plasmodium invasion of the mosquito midgut allows contact of the gut microbiota with epithelial cells. This event is followed by a systemic release of a hemocyte differentiation factor (HDF) consisting of Lipoxin A4 bound to Evokin, a lipocalin carrier, which increases the proportion of circulating hemocytes.

The Aedes aegypti IMD pathway is a critical component of the mosquito antifungal immune response.

Successful infection of the insect body by entomopathogenic fungi is the result of complex molecular interactions between the host and the invading pathogenic fungi. The mosquito antifungal response is multifaceted and is regulated in part by the Toll and Jak-STAT pathways. Here, we assessed the role of the IMD pathway in the mosquito Ae.

Entomopathogenic fungal infection leads to temporospatial modulation of the mosquito immune system.

Alternative methods of mosquito control are needed to tackle the rising burden of mosquito-borne diseases while minimizing the use of synthetic insecticides, which are threatened by the rapid increase in insecticide resistance in mosquito populations. Fungal biopesticides show great promise as potential alternatives because of their ecofriendly nature and ability to infect mosquitoes on contact. Here we describe the temporospatial interactions between the mosquito Aedes aegypti and several entomopathogenic fungi.

Microbiota activates IMD pathway and limits Sindbis infection in Aedes aegypti.

Background: Aedes aegypti is the main vector of important arboviruses such as dengue, Zika and chikungunya. During infections mosquitoes can activate the immune pathways Toll, IMD and JAK/STAT to limit pathogen replication.

Results: Here, we evaluate the immune response profile of Ae.

Tyrosine Detoxification Is an Essential Trait in the Life History of Blood-Feeding Arthropods.

Blood-feeding arthropods are vectors of infectious diseases such as dengue, Zika, Chagas disease, and malaria [1], and vector control is essential to limiting disease spread. Because these arthropods ingest very large amounts of blood, a protein-rich meal, huge amounts of amino acids are produced during digestion. Previous work on Rhodnius prolixus, a vector of Chagas disease, showed that, among all amino acids, only tyrosine degradation enzymes were overexpressed in the midgut compared to other tissues [2].

Validation of Aedes aegypti Aag-2 cells as a model for insect immune studies.

Background: The understanding of mosquito immune responses can provide valuable tools for development of novel mosquito control strategies. Aiming the study at insect innate immunity, continuous insect cell lines have been established and used as research tools due to the fact that they constitute more homogeneous, sensitive, and reproducible systems than the insects from which they originated. More recently, Aag-2, an Aedes aegypti cell lineage, began to be frequently used as a model for studies of mosquito immunity.