Publications by authors named "Thiago L Alves E Silva"

Article Synopsis
  • The evolution of blood-feeding insects, like mosquitoes, involves adaptations that help them consume blood while avoiding the host's immune responses.
  • Anopheles gambiae salivary apyrase (AgApyrase) plays a key role in blood meal hemostasis by inhibiting platelet aggregation and facilitating the conversion of plasminogen to plasmin, which helps in degrading fibrin and promotes Plasmodium transmission.
  • Immunizing against AgApyrase can inhibit Plasmodium infection and transmission, suggesting potential strategies for preventing malaria spread.
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In arthropods, hemolymph carries immune cells and solubilizes and transports nutrients, hormones, and other molecules that are involved in diverse physiological processes including immunity, metabolism, and reproduction. However, despite such physiological importance, little is known about its composition. We applied mass spectrometry-based label-free quantification approaches to study the proteome of hemolymph perfused from sugar-fed female and male mosquitoes.

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Malaria transmission by mosquitoes is very effective, in part because the parasite expresses a surface protein called Pfs47 that allows it to evade the mosquito immune system. Here we investigate how this protein changes the response of mosquito midgut epithelial cells to invasion by the parasite. Pfs47 is known to interact with P47Rec, a mosquito midgut receptor.

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  • Natural IgM antibodies (IgMn) play a key role in facilitating genetic exchange among Leishmania parasites by inducing the formation of transient clumps that promote fusion and hybridization.
  • IgMn from Leishmania-free animals binds to the parasites' surface, causing significant changes in their transcript and protein expression, although this binding is partially reduced after glycosidase treatment.
  • Increased hybrid formation occurs in sand flies that receive IgMn through a second blood meal, demonstrating a strong link between host antibodies and parasite genetic diversity, ultimately enhancing the fitness of Leishmania.
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Article Synopsis
  • Mosquito salivary proteins, especially salivary apyrase (AgApyrase), play a key role in managing blood clotting during a mosquito bite, which is important for the transmission of diseases like malaria.
  • The study shows that AgApyrase activates a human protein called tissue plasminogen activator, leading to increased plasmin production that helps mosquitoes digest blood more effectively and increases their infection rates.
  • Immunizing against AgApyrase was found to reduce mosquito infection and limit the spread of malaria, suggesting potential new methods for preventing transmission of the disease.
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Malaria inflicts the highest rate of morbidity and mortality among the vector-borne diseases. The dramatic bottleneck of parasite numbers that occurs in the gut of the obligatory mosquito vector provides a promising target for novel control strategies. Using single-cell transcriptomics, we analyzed Plasmodium falciparum development in the mosquito gut, from unfertilized female gametes through the first 20 h after blood feeding, including the zygote and ookinete stages.

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Immunohistochemistry is a valuable technique that provides information on protein localization and interactions in tissues. Mosquito salivary gland immunohistochemistry requires the meticulous dissection of a delicate tissue. The integrity of the salivary glands must be closely monitored throughout the entire process to prevent structural damage and loss of saliva.

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Studying protein localization in mosquito salivary glands provides novel insights on the function and physiological relevance of salivary proteins and also provides an avenue to study interactions between mosquitoes and pathogens. Salivary proteins display compartmentalization. For example, proteins involved in blood feeding are stored in the medial and distal lateral lobes, whereas proteins related to sugar metabolism localize to the proximal portion of the lateral lobes.

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In mammals, the serine protease plasmin degrades extracellular proteins during blood clot removal, tissue remodeling, and cell migration. The zymogen plasminogen is activated into plasmin by two serine proteases: tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), a process regulated by plasminogen activator inhibitor 1 (PAI-1), a serine protease inhibitor that specifically inhibits tPA and uPA. Plasmodium gametes and sporozoites use tPA and uPA to activate plasminogen and parasite-bound plasmin degrades extracellular matrices, facilitating parasite motility in the mosquito and the mammalian host.

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Plasmodium and other vector-borne pathogens have evolved mechanisms to hijack the mammalian fibrinolytic system to facilitate infection of the human host and the invertebrate vector. Plasmin, the effector protease of fibrinolysis, maintains homeostasis in the blood vasculature by degrading the fibrin that forms blood clots. Plasmin also degrades proteins from extracellular matrices, the complement system, and immunoglobulins.

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Anopheles mosquitoes feed on plant nectars as their main source of sugar. Wang et al. show that Asaia bacteria proliferate in the midgut of mosquitoes that feed on glucose or trehalose.

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Malaria elimination requires tools that interrupt parasite transmission. Here, we characterize B cell receptor responses among Malian adults vaccinated against the first domain of the cysteine-rich 230 kDa gamete surface protein Pfs230, a key protein in sexual stage development of P. falciparum parasites.

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Article Synopsis
  • Parasites need to move through protein-rich barriers to infect mosquitoes and their vertebrate hosts, and they use human plasminogen to aid in this process.
  • The study finds that blocking the activation of plasminogen stops parasite development early in their life cycle, which occurs before a critical stage known as ookinete formation.
  • Increased levels of fibrinogen in the blood actually reduce the parasites' ability to infect mosquitoes, and the presence of plasmin on the surface of parasites enhances their movement, suggesting that targeting the fibrinolytic system could be a strategy to prevent transmission.
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mating is initiated by the swarming of males at dusk followed by females flying into the swarm. Here, we show that mosquito swarming and mating are coordinately guided by clock genes, light, and temperature. Transcriptome analysis shows up-regulation of the clock genes () and () in the head of field-caught swarming males.

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Mosquito physiology and immunity are integral determinants of malaria vector competence. This includes the principal role of hormonal signaling in Anopheles gambiae initiated shortly after blood-feeding, which stimulates immune induction and promotes vitellogenesis through the function of 20-hydroxyecdysone (20E). Previous studies demonstrated that manipulating 20E signaling through the direct injection of 20E or the application of a 20E agonist can significantly impact Plasmodium infection outcomes, reducing oocyst numbers and the potential for malaria transmission.

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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.

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The surface protein Pfs47 allows parasites to survive and be transmitted by making them "undetectable" to the mosquito immune system. parasites express Pfs47 haplotypes compatible with their sympatric vectors, while those with incompatible haplotypes are eliminated by the mosquito. We proposed that Pfs47 serves as a "key" that mediates immune evasion by interacting with a mosquito receptor "the lock," which differs in evolutionarily divergent anopheline mosquitoes.

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Trypanosomatids are protozoan parasites that infect thousands of globally dispersed hosts, potentially affecting their physiology. Several species of trypanosomatids are commonly found in phytophagous insects. Leptomonas wallacei is a gut-restricted insect trypanosomatid only retrieved from Oncopeltus fasciatus.

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A naturally occurring strain (Anga-Mali) was identified in mosquitoes of the complex collected in the Malian villages of Dangassa and Kenieroba. Phylogenetic analysis of the nucleotide sequence of two 16S rRNA regions showed that Anga-Mali clusters with strains from supergroup A and has the highest homology to a strain isolated from cat fleas (). Anga-Mali is different from two strains previously reported in from Burkina Faso (Anga_VK5_STP and Anga_VK5_3.

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African trypanosomes (Trypanosoma brucei spp.) cause devastating diseases in sub-Saharan Africa. Trypanosomes differentiate repeatedly during development in tsetse flies before gaining mammalian infectivity in fly salivary glands.

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Tsetse are vectors of pathogenic trypanosomes, agents of human and animal trypanosomiasis in Africa. Components of tsetse saliva (sialome) are introduced into the mammalian host bite site during the blood feeding process and are important for tsetse's ability to feed efficiently, but can also influence disease transmission and serve as biomarkers for host exposure. We compared the sialome components from four tsetse species in two subgenera: subgenus Morsitans: Glossina morsitans morsitans (Gmm) and Glossina pallidipes (Gpd), and subgenus Palpalis: Glossina palpalis gambiensis (Gpg) and Glossina fuscipes fuscipes (Gff), and evaluated their immunogenicity and serological cross reactivity by an immunoblot approach utilizing antibodies from experimental mice challenged with uninfected flies.

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The agents of sleeping sickness disease, Trypanosoma brucei complex parasites, are transmitted to mammalian hosts through the bite of an infected tsetse. Information on tsetse-trypanosome interactions in the salivary gland (SG) tissue, and on mammalian infective metacyclic (MC) parasites present in the SG, is sparse. We performed RNA-seq analyses from uninfected and T.

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The genus Phytomonas includes parasites that are etiological agents of important plant diseases, especially in Central and South America. These parasites are transmitted to plants via the bite of an infected phytophagous hemipteran. Despite the economic impact of these parasites, many basic questions regarding the genus Phytomonas remain unanswered, such as the mechanism by which the parasites cope with the immune response of the insect vector.

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Phytomonas species are plant parasites of the family Trypanosomatidae, which are transmitted by phytophagous insects. Some Phytomonas species cause major agricultural damages. The hemipteran Oncopeltus fasciatus is natural and experimental host for several species of trypanosomatids, including Phytomonas spp.

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