The Dose Makes the Poison: Nutritional Overload Determines the Life Traits of Blood-Feeding Arthropods.

Vertebrate blood composition is heavily biased towards proteins, and hemoglobin, which is a hemeprotein, is by far the most abundant protein. Typically, hematophagous insects ingest blood volumes several times their weight before the blood meal. This barbarian feast offers an abundance of nutrients, but the degradation of blood proteins generates toxic concentrations of amino acids and heme, along with unparalleled microbiota growth. Despite this challenge, hematophagous arthropods have successfully developed mechanisms that bypass the toxicity of these molecules. While these adaptations allow hematophagous arthropods to tolerate their diet, they also constitute a unique mode of operation for cell signaling, immunity, and metabolism, the study of which may offer insights into the biology of disease vectors and may lead to novel vector-specific control methods.

Proteases of haematophagous arthropod vectors are involved in blood-feeding, yolk formation and immunity - a review.

Ticks, triatomines, mosquitoes and sand flies comprise a large number of haematophagous arthropods considered vectors of human infectious diseases. While consuming blood to obtain the nutrients necessary to carry on life functions, these insects can transmit pathogenic microorganisms to the vertebrate host. Among the molecules related to the blood-feeding habit, proteases play an essential role. In this review, we provide a panorama of proteases from arthropod vectors involved in haematophagy, in digestion, in egg development and in immunity. As these molecules act in central biological processes, proteases from haematophagous vectors of infectious diseases may influence vector competence to transmit pathogens to their prey, and thus could be valuable targets for vectorial control.

Haematophagous arthropod saliva and host defense system: a tale of tear and blood.

The saliva from blood-feeding arthropod vectors is enriched with molecules that display diverse functions that mediate a successful blood meal. They function not only as weapons against host's haemostatic, inflammatory and immune responses but also as important tools to pathogen establishment. Parasites, virus and bacteria taking advantage of vectors' armament have adapted to facilitate their entry in the host. Today, many salivary molecules have been identified and characterized as new targets to the development of future vaccines. Here we focus on current information on vector's saliva and the molecules responsible to modify host's hemostasis and immune response, also regarding their role in disease transmission.

Haematophagous arthropod saliva and host defense system: a tale of tear and blood

A saliva de artrópodes hematófagos é rica em moléculas com funções diversas que mediam uma alimentação sangüínea bem sucedida. Estas moléculas agem não apenas como armas contra a resposta hemostática, inflamatória e imunológica do hospedeiro funcionando também como ferramentas para o estabelecimento de patógenos. Parasitas, vírus e bactérias aproveitando-se deste arsenal dos vetores adaptaram-se facilitando seu estabelecimento no hospedeiro. Hoje, várias moléculas salivares foram identificadas e caracterizadas como novos alvos para o desenvolvimento de vacinas futuras. Neste trabalho, centramos em informação recente sobre a saliva de vetores e as moléculas responsáveis por modificar a resposta hemostática e imunológica assim como seu papel na transmissão de doenças.