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1.
Insect Biochem Mol Biol ; 153: 103898, 2023 02.
Article de Anglais | MEDLINE | ID: mdl-36587808

RÉSUMÉ

Mosquitoes are responsible for the death and debilitation of millions of people every year due to the pathogens they can transmit while blood feeding. While a handful of mosquitoes, namely those in the Aedes, Anopheles, and Culex genus, are the dominant vectors, many other species belonging to different genus are also involved in various pathogen cycles. Sabethes cyaneus is one of the many poorly understood mosquito species involved in the sylvatic cycle of Yellow Fever Virus. Here, we report the expression profile differences between male and female of Sa.cyaneus salivary glands (SGs). We find that female Sa.cyaneus SGs have 165 up-regulated and 18 down-regulated genes compared to male SGs. Most of the up-regulated genes have unknown functions, however, odorant binding proteins, such as those in the D7 protein family, and mucins were among the top 30 genes. We also performed various in vitro activity assays of female SGs. In the activity analysis we found that female SG extracts inhibit coagulation by blocking factor Xa and has endonuclease activity. Knowledge about mosquitoes and their physiology are important for understanding how different species differ in their ability to feed on and transmits pathogens to humans. These results provide us with an insight into the Sabethes SG activity and gene expression that expands our understanding of mosquito salivary glands.


Sujet(s)
Aedes , Anopheles , Humains , Mâle , Femelle , Animaux , Transcriptome , Vecteurs moustiques , Glandes salivaires/métabolisme , Anopheles/génétique , Anopheles/métabolisme , Aedes/génétique
2.
Lancet Infect Dis ; 23(5): 578-588, 2023 05.
Article de Anglais | MEDLINE | ID: mdl-36708738

RÉSUMÉ

BACKGROUND: Human monoclonal antibodies might offer an important new approach to reduce malaria morbidity and mortality. In the first two parts of a three-part clinical trial, the antimalarial monoclonal antibody CIS43LS conferred high protection against parasitaemia at doses of 20 mg/kg or 40 mg/kg administered intravenously followed by controlled human malaria infection. The ability of CIS43LS to confer protection at lower doses or by the subcutaneous route is unknown. We aimed to provide data on the safety and optimisation of dose and route for the human antimalaria monoclonal antibody CIS43LS. METHODS: VRC 612 Part C was the third part of a three-part, first-in-human, phase 1, adaptive trial, conducted at the University of Maryland, Baltimore Center for Vaccine Development and Global Health, Baltimore, MD, USA. We enrolled adults aged 18-50 years with no previous malaria vaccinations or infections, in a sequential, dose-escalating manner. Eligible participants received the monoclonal antibody CIS43LS in a single, open-label dose of 1 mg/kg, 5 mg/kg, or 10 mg/kg intravenously, or 5 mg/kg or 10 mg/kg subcutaneously. Participants underwent controlled human malaria infection by the bites of five mosquitoes infected with Plasmodium falciparum 3D7 strain approximately 8 weeks after their monoclonal antibody inoculation. Six additional control participants who did not receive CIS43LS underwent controlled human malaria infection simultaneously. Participants were followed-up daily on days 7-18 and day 21, with qualitative PCR used for P falciparum detection. Participants who tested positive for P falciparum were treated with atovaquone-proguanil and those who remained negative were treated at day 21. Participants were followed-up until 24 weeks after dosing. The primary outcome was safety and tolerability of CIS43LS at each dose level, assessed in the as-treated population. Secondary outcomes included protective efficacy of CIS43LS after controlled human malaria infection. This trial is now complete and is registered with ClinicalTrials.gov, NCT04206332. FINDINGS: Between Sept 1, 2021, and Oct 29, 2021, 47 people were assessed for eligibility and 31 were enrolled (one subsequently withdrew and was replaced) and assigned to receive doses of 1 mg/kg (n=7), 5 mg/kg (n=4), and 10 mg/kg (n=3) intravenously and 5 mg/kg (n=4) and 10 mg/kg (n=4) subcutaneously, or to the control group (n=8). CIS43LS administration was safe and well tolerated; no serious adverse events occurred. CIS43LS protected 18 (82%) of 22 participants who received a dose. No participants developed parasitaemia following dosing at 5 mg/kg intravenously or subcutaneously, or at 10 mg/kg intravenously or subcutaneously. All six control participants and four of seven participants dosed at 1 mg/kg intravenously developed parasitaemia after controlled human malaria infection. INTERPRETATION: CIS43LS was safe and well tolerated, and conferred protection against P falciparum at low doses and by the subcutaneous route, providing evidence that this approach might be useful to prevent malaria across several clinical use cases. FUNDING: National Institute of Allergy and Infectious Diseases, National Institutes of Health.


Sujet(s)
Antipaludiques , Vaccins contre le paludisme , Paludisme à Plasmodium falciparum , Adulte , Animaux , Humains , Anticorps monoclonaux/usage thérapeutique , Paludisme à Plasmodium falciparum/traitement médicamenteux , Paludisme à Plasmodium falciparum/prévention et contrôle , Plasmodium falciparum , Vaccins contre le paludisme/usage thérapeutique
3.
Immunohorizons ; 6(6): 373-383, 2022 06 23.
Article de Anglais | MEDLINE | ID: mdl-35738824

RÉSUMÉ

Blood-feeding arthropods secrete potent salivary molecules, which include platelet aggregation inhibitors, vasodilators, and anticoagulants. Among these molecules, Alboserpin, the major salivary anticoagulant from the mosquito vector Aedes albopictus, is a specific inhibitor of the human coagulation factor Xa (FXa). In this study, we investigated the anti-inflammatory properties of Alboserpin, in vitro and in vivo. In vitro, Alboserpin inhibited FXa-induced protease-activated receptor (PAR)-1, PAR-2, PAR-3, VCAM, ICAM, and NF-κB gene expression in primary dermal microvascular endothelial cells. Alboserpin also prevented FXa-stimulated ERK1/2 gene expression and subsequent inflammatory cytokine release (MCP-1, TNF-α, IL-6, IL-8, IL-1ß, IL-18). In vivo, Alboserpin reduced paw edema induced by FXa and subsequent release of inflammatory cytokines (CCL2, MCP-1, IL-1α, IL-6, IL-1ß). Alboserpin also reduced FXa-induced endothelial permeability in vitro and in vivo. These findings show that Alboserpin is a potent anti-inflammatory molecule, in vivo and in vitro, and may play a significant role in blood feeding.


Sujet(s)
Aedes , Aedes/métabolisme , Animaux , Anti-inflammatoires/pharmacologie , Anticoagulants/pharmacologie , Cytokines , Cellules endothéliales/métabolisme , Humains , Interleukine-6 , Vecteurs moustiques , Récepteur de type PAR-1/génétique , Récepteur de type PAR-1/métabolisme
4.
Curr Res Struct Biol ; 3: 95-105, 2021.
Article de Anglais | MEDLINE | ID: mdl-34235489

RÉSUMÉ

Female mosquitoes require blood meals for egg development. The saliva of blood feeding arthropods contains biochemically active molecules, whose anti-hemostatic and anti-inflammatory properties facilitate blood feeding on vertebrate hosts. While transcriptomics has presented new opportunities to investigate the diversity of salivary proteins from hematophagous arthropods, many of these proteins remain functionally undescribed. Previous transcriptomic analysis of female salivary glands from Culex quinquefasciatus, an important vector of parasitic and viral infections, uncovered a 12-member family of putatively secreted proteins of unknown function, named the Cysteine and Tryptophan-Rich (CWRC) proteins. Here, we present advances in the characterization of two C. quinquefasciatus CWRC family members, CqDVP-2 and CqDVP-4, including their enrichment in female salivary glands, their specific localization within salivary gland tissues, evidence that these proteins are secreted into the saliva, and their native crystal structures, at 2.3 â€‹Å and 1.87 â€‹Å, respectively. The ß-trefoil fold common to CqDVP-2 and CqDVP-4 is similar to carbohydrate-binding proteins, including the B subunit of the AB toxin, ricin, from the castor bean Ricinus communis. Further, we used a glycan array approach, which identifies carbohydrate ligands associated with inflammatory processes and signal transduction. Glycan array 300 testing identified 100 carbohydrate moieties with positive binding to CqDVP-2, and 77 glycans with positive binding to CqDVP-4. The glycan with the highest relative fluorescence intensities, which exhibited binding to both CqDVP-2 and CqDVP-4, was used for molecular docking experiments. We hypothesize that these proteins bind to carbohydrates on the surface of cells important to host immunology. Given that saliva is deposited into the skin during a mosquito bite, and acts as the vehicle for arbovirus inoculation, understanding the role of these proteins in pathogen transmission is of critical importance. This work presents the first solved crystal structures of C. quinquefasciatus salivary proteins with unknown function. These two molecules are the second and third structures reported from salivary proteins from C. quinquefasciatus, an important, yet understudied disease vector.

5.
Biomolecules ; 10(10)2020 09 27.
Article de Anglais | MEDLINE | ID: mdl-32992542

RÉSUMÉ

Mosquitoes inject saliva into the host skin to facilitate blood meal acquisition through active compounds that prevent hemostasis. D7 proteins are among the most abundant components of the mosquito saliva and act as scavengers of biogenic amines and eicosanoids. Several members of the D7 family have been characterized at the biochemical level; however, none have been studied thus far in Aedes albopictus, a permissive vector for several arboviruses that causes extensive human morbidity and mortality. Here, we report the binding capabilities of a D7 long form protein from Ae. albopictus (AlboD7L1) by isothermal titration calorimetry and compared its model structure with previously solved D7 structures. The physiological function of AlboD7L1 was demonstrated by ex vivo platelet aggregation and in vivo leukocyte recruitment experiments. AlboD7L1 binds host hemostasis agonists, including biogenic amines, leukotrienes, and the thromboxane A2 analog U-46619. AlboD7L1 protein model predicts binding of biolipids through its N-terminal domain, while the C-terminal domain binds biogenic amines. We demonstrated the biological function of AlboD7L1 as an inhibitor of both platelet aggregation and cell recruitment of neutrophils and eosinophils. Altogether, this study reinforces the physiological relevance of the D7 salivary proteins as anti-hemostatic and anti-inflammatory molecules that help blood feeding in mosquitoes.


Sujet(s)
Aedes/composition chimique , Interactions hôte-pathogène/effets des médicaments et des substances chimiques , Inflammation/génétique , Protéines d'insecte/composition chimique , Animaux , Hémostase/effets des médicaments et des substances chimiques , Humains , Inflammation/prévention et contrôle , Protéines d'insecte/génétique , Protéines d'insecte/pharmacologie , Leucocytes/effets des médicaments et des substances chimiques , Agrégation plaquettaire/effets des médicaments et des substances chimiques , Liaison aux protéines/effets des médicaments et des substances chimiques , Salive/composition chimique , Protéines et peptides salivaires/composition chimique , Protéines et peptides salivaires/pharmacologie
6.
Nat Commun ; 11(1): 2911, 2020 06 09.
Article de Anglais | MEDLINE | ID: mdl-32518308

RÉSUMÉ

During blood-feeding, mosquito saliva is injected into the skin to facilitate blood meal acquisition. D7 proteins are among the most abundant components of the mosquito saliva. Here we report the ligand binding specificity and physiological relevance of two D7 long proteins from Culex quinquefasciatus mosquito, the vector of filaria parasites or West Nile viruses. CxD7L2 binds biogenic amines and eicosanoids. CxD7L1 exhibits high affinity for ADP and ATP, a binding capacity not reported in any D7. We solve the crystal structure of CxD7L1 in complex with ADP to 1.97 Å resolution. The binding pocket lies between the two protein domains, whereas all known D7s bind ligands either within the N- or the C-terminal domains. We demonstrate that these proteins inhibit hemostasis in ex vivo and in vivo experiments. Our results suggest that the ADP-binding function acquired by CxD7L1 evolved to enhance blood-feeding in mammals, where ADP plays a key role in platelet aggregation.


Sujet(s)
ADP/composition chimique , Culex/composition chimique , Vecteurs moustiques , Protéines et peptides salivaires/composition chimique , Adénosine triphosphate/composition chimique , Animaux , Sites de fixation , Biologie informatique/méthodes , Cristallographie aux rayons X , Éicosanoïdes/composition chimique , Comportement alimentaire , Analyse de profil d'expression de gènes , Hémostase , Humains , Protéines d'insecte/composition chimique , Ligands , Nucléotides/composition chimique , Agrégation plaquettaire , Liaison aux protéines , Domaines protéiques , Salive/composition chimique , Thermodynamique
7.
PLoS Pathog ; 14(5): e1007006, 2018 05.
Article de Anglais | MEDLINE | ID: mdl-29723281

RÉSUMÉ

Salivary components from disease vectors help arthropods to acquire blood and have been shown to enhance pathogen transmission in different model systems. Here we show that two salivary enzymes from Lutzomyia longipalpis have a synergist effect that facilitates a more efficient blood meal intake and diffusion of other sialome components. We have previously shown that Lundep, a highly active endonuclease, enhances parasite infection and prevent blood clotting by inhibiting the intrinsic pathway of coagulation. To investigate the physiological role of a salivary hyaluronidase in blood feeding we cloned and expressed a recombinant hyaluronidase from Lu. longipalpis. Recombinant hyaluronidase (LuloHya) was expressed in mammalian cells and biochemically characterized in vitro. Our study showed that expression of neutrophil CXC chemokines and colony stimulating factors were upregulated in HMVEC cells after incubation with LuloHya and Lundep. These results were confirmed by the acute hemorrhage, edema and inflammation in a dermal necrosis (dermonecrotic) assay involving a massive infiltration of leukocytes, especially neutrophils, in mice co-injected with hemorrhagic factor and these two salivary proteins. Moreover, flow cytometry results showed that LuloHya and Lundep promote neutrophil recruitment to the bite site that may serve as a vehicle for establishment of Leishmania infection. A vaccination experiment demonstrated that LuloHya and Lundep confer protective immunity against cutaneous leishmaniasis using the Lu. longipalpis-Leishmania major combination as a model. Animals (C57BL/6) immunized with LuloHya or Lundep showed minimal skin damage while lesions in control animals remained ulcerated. This protective immunity was abrogated when B-cell-deficient mice were used indicating that antibodies against both proteins play a significant role for disease protection. Rabbit-raised anti-LuloHya antibodies completely abrogated hyaluronidase activity in vitro. Moreover, in vivo experiments demonstrated that blocking LuloHya with specific antibodies interferes with sand fly blood feeding. This work highlights the relevance of vector salivary components in blood feeding and parasite transmission and further suggests the inclusion of these salivary proteins as components for an anti-Leishmania vaccine.


Sujet(s)
Hyaluronoglucosaminidase/immunologie , Leishmania major/immunologie , Leishmania major/pathogénicité , Leishmaniose cutanée/immunologie , Leishmaniose cutanée/prévention et contrôle , Psychodidae/immunologie , Animaux , Simulation numérique , Endonucleases/immunologie , Femelle , Interactions hôte-pathogène/immunologie , Humains , Hyaluronoglucosaminidase/composition chimique , Protéines d'insecte/composition chimique , Protéines d'insecte/immunologie , Souris , Souris de souche-129 , Souris de lignée C57BL , Modèles moléculaires , Granulocytes neutrophiles/immunologie , Polysaccharide-lyases/immunologie , Lapins , Salive/enzymologie , Salive/immunologie
8.
Proc Natl Acad Sci U S A ; 111(19): 6946-51, 2014 May 13.
Article de Anglais | MEDLINE | ID: mdl-24778255

RÉSUMÉ

Mosquito salivary glands have important roles in blood feeding and pathogen transmission. However, the biological relevance of many salivary components has yet to be determined. Aegyptin, a secreted salivary protein from Aedes aegypti, binds collagen and inhibits platelet aggregation and adhesion. We used a transgenic approach to study the relevance of Aegyptin in mosquito blood feeding. Aedes aegypti manipulated genetically to express gene-specific inverted-repeat RNA sequences exhibited significant reductions in Aegyptin mRNA accumulation (85-87%) and protein levels (>80-fold) in female mosquito salivary glands. Transgenic mosquitoes had longer probing times (78-300 s, P < 0.0001) when feeding on mice compared with controls (15-56 s), feeding success was reduced, and those feeding took smaller blood meals. However, no differences in feeding success or blood meal size were found in membrane feeding experiments using defibrinated human blood. Salivary gland extracts from transgenic mosquitoes failed to inhibit collagen-induced platelet aggregation in vitro. Reductions of Aegyptin did not affect salivary ADP-induced platelet aggregation inhibition or disturb anticlotting activities. Our results demonstrate the relevance of Aegyptin for A. aegypti blood feeding, providing further support for the hypothesis that platelet aggregation inhibition is a vital salivary function in blood feeding arthropods. It has been suggested that the multiple mosquito salivary components mediating platelet aggregation (i.e., Aegyptin, apyrase, D7) represent functional redundancy. Our findings do not support this hypothesis; instead, they indicate that multiple salivary components work synergistically and are necessary to achieve maximum blood feeding efficiency.


Sujet(s)
Aedes/génétique , Aedes/virologie , Virus de la dengue/génétique , Comportement alimentaire , Protéines d'insecte/génétique , Protéines et peptides salivaires/génétique , Aedes/physiologie , Animaux , Animal génétiquement modifié , Spécificité des anticorps , Séquence nucléotidique , Coagulation sanguine/physiologie , Protéines du sang/physiologie , Collagène/métabolisme , Femelle , Extinction de l'expression des gènes , Humains , Protéines d'insecte/métabolisme , Mâle , Souris , Données de séquences moléculaires , Agrégation plaquettaire/physiologie , Lapins , Protéines recombinantes/génétique , Protéines recombinantes/immunologie , Protéines recombinantes/métabolisme , Salive/métabolisme , Protéines et peptides salivaires/métabolisme
9.
Belo Horizonte; s.n; 2011. xxii,162 p. ilus.
Thèse de Portugais | LILACS, Coleciona SUS | ID: biblio-937926

RÉSUMÉ

O simulídeo Thyrsopelma guianense é o principal vetor da oncocercose no Brasil, e pouco se conhece sobre a composição e função da saliva em simulídeos. Artrópodes hematófagos contém uma “poção mágica” para interagir com à hemostase, inflamação e imunidade de seus hospedeiros. A glândula salivar de fêmeas de T. guianense é constituída de dois lobos idênticos contendo uma glândula principal (envolvida com a alimentação com sangue) e uma acessória (envolvida com a alimentação com açúcar), a última similar à glândula de macho. A análise histoquímica demonstrou uma saliva é rica em polissacarídeos, proteínas e lipídios principalmente na glândula principal. Essa região contém cavidades secretoras elétron-densas, enquanto, o lúmen da glândula acessória é elétron-lucente. Os homogenados salivares inibiram a coagulação sanguínea, atuando em fXa mas não em trombina. Esses homogenados também apresentaram atividade enzimática de lisozima em pH 7,0.


O sialotranscriptoma isolou e identificou 1.772 transcritos, classificados como secretores (S) (74,7%), celulares (C) (16,2%), produtos de função desconhecida (U) (9%) e elementos de transposição (0,1%). Esse sialotranscriptoma identificou famílias de proteínas ubíquas como antígeno-5, Yellow, domínios ML, lipocalina, lisozima, cecropina, serpina, domínios Kunitz, serino proteases, hialuronidase, apirase, glicosidases, adenosina deaminase e destabilase, além de famílias de proteínas específicas para insetos como Aegyptina e a superfamília D7/OBP. Cerca de 63,4% dos produtos secretores corresponderam a famílias de proteínas encontradas somente em Simulium, como SVEP/Marydilan, proteínas ácidas ricas em His, Sv 7,8 kDa, mucinas, tipo-colágeno, básicas 7-13 kDa, Sv 7,8 kDa, 4,8 kDa, básicas 7,4 kDa, básica 13 kDa e família 5-Cys. Várias famílias de proteínas foram deorfanizadas do sialotranscriptoma de S. nigrimanum como Sn 8-10 Cys W, ácida 28 kDa, básica 28 kD, 19 kDa, básica 8 kDa e Sn básica 4,4 kDa. Transcritos com similaridade para kunitoxina foram encontrados em T. guianense. Observamos um aumento na expressão de transcritos para a classe S e expecionalmente em SVEP, e nos subgrupos síntese de proteína e metabolismo energético da classe C, em relação a outros sialotranscriptomas de Simulium. O proteoma confirmou 28 das 32 famílias de proteínas encontradas no transcriptoma e disponibilizamos 101 sequências de proteínas de interesse para o NCBI. Essa é a primeira descrição de um sialoma (do grego Greek Sialo=saliva) de um vetor de oncocercose. Assim, nossos resultados ajudam no entendimento do papel da saliva de Simulium na transmissão de Onchocerca volvulus e para a evolução de proteínas salivares em simulídeos, além de consistir numa plataforma de novos compostos antihemostáticos e candidatos a vacina contra oncocercose.


Sujet(s)
Humains , Animaux , Bovins , Onchocercose/transmission , Glandes salivaires
10.
Belo Horizonte; s.n; 2011. xxii,162 p. ilus.
Thèse de Portugais | LILACS | ID: lil-658784

RÉSUMÉ

O simulídeo Thyrsopelma guianense é o principal vetor da oncocercose no Brasil, e pouco se conhece sobre a composição e função da saliva em simulídeos. Artrópodes hematófagos contém uma “poção mágica” para interagir com à hemostase, inflamação e imunidade de seus hospedeiros. A glândula salivar de fêmeas de T. guianense é constituída de dois lobos idênticos contendo uma glândula principal (envolvida com a alimentação com sangue) e uma acessória (envolvida com a alimentação com açúcar), a última similar à glândula de macho. A análise histoquímica demonstrou uma saliva é rica em polissacarídeos, proteínas e lipídios principalmente na glândula principal. Essa região contém cavidades secretoras elétron-densas, enquanto, o lúmen da glândula acessória é elétron-lucente. Os homogenados salivares inibiram a coagulação sanguínea, atuando em fXa mas não em trombina. Esses homogenados também apresentaram atividade enzimática de lisozima em pH 7,0.


O sialotranscriptoma isolou e identificou 1.772 transcritos, classificados como secretores (S) (74,7%), celulares (C) (16,2%), produtos de função desconhecida (U) (9%) e elementos de transposição (0,1%). Esse sialotranscriptoma identificou famílias de proteínas ubíquas como antígeno-5, Yellow, domínios ML, lipocalina, lisozima, cecropina, serpina, domínios Kunitz, serino proteases, hialuronidase, apirase, glicosidases, adenosina deaminase e destabilase, além de famílias de proteínas específicas para insetos como Aegyptina e a superfamília D7/OBP. Cerca de 63,4% dos produtos secretores corresponderam a famílias de proteínas encontradas somente em Simulium, como SVEP/Marydilan, proteínas ácidas ricas em His, Sv 7,8 kDa, mucinas, tipo-colágeno, básicas 7-13 kDa, Sv 7,8 kDa, 4,8 kDa, básicas 7,4 kDa, básica 13 kDa e família 5-Cys. Várias famílias de proteínas foram deorfanizadas do sialotranscriptoma de S. nigrimanum como Sn 8-10 Cys W, ácida 28 kDa, básica 28 kD, 19 kDa, básica 8 kDa e Sn básica 4,4 kDa. Transcritos com similaridade para kunitoxina foram encontrados em T. guianense. Observamos um aumento na expressão de transcritos para a classe S e expecionalmente em SVEP, e nos subgrupos síntese de proteína e metabolismo energético da classe C, em relação a outros sialotranscriptomas de Simulium. O proteoma confirmou 28 das 32 famílias de proteínas encontradas no transcriptoma e disponibilizamos 101 sequências de proteínas de interesse para o NCBI. Essa é a primeira descrição de um sialoma (do grego Greek Sialo=saliva) de um vetor de oncocercose. Assim, nossos resultados ajudam no entendimento do papel da saliva de Simulium na transmissão de Onchocerca volvulus e para a evolução de proteínas salivares em simulídeos, além de consistir numa plataforma de novos compostos antihemostáticos e candidatos a vacina contra oncocercose.


Sujet(s)
Humains , Animaux , Bovins , Glandes salivaires , Onchocercose/transmission
11.
Mem Inst Oswaldo Cruz ; 105(2): 174-8, 2010 Mar.
Article de Anglais | MEDLINE | ID: mdl-20428677

RÉSUMÉ

In this study, anticoagulant activity was detected in salivary gland homogenates (SGHs) of Thyrsopelma guianense (Diptera: Simuliidae). The SGH yielded 1.07 microg +/- 0.03 (n = 15) of total soluble protein per pair of glands. In addition, following SDS-PAGE (12.5% gel) and silver nitrate staining, 12 polypeptides with molecular weights ranging from 14-69 kDa were detected in all physiological ages analyzed (12 h, 24 h, 48 h and 72 h following emergence). Coagulation bioassays showed that the SGHs had activities that interacted at all levels of coagulation (the intrinsic, extrinsic and common pathways), by extending the plasma recalcification time, prothrombin time, thrombin time. This is the first report on the activity of salivary gland proteins from the main vector of onchocerciasis in Brazil. We also suggest detailed studies on the morphology and function of the salivary glands in order to understand the role of these proteins in host/vector interactions.


Sujet(s)
Anticoagulants/pharmacologie , Protéines d'insecte/pharmacologie , Vecteurs insectes/composition chimique , Glandes salivaires/composition chimique , Simuliidae/composition chimique , Animaux , Anticoagulants/isolement et purification , Brésil , Électrophorèse sur gel de polyacrylamide , Femelle , Humains , Protéines d'insecte/isolement et purification , Onchocercose/transmission , Facteurs temps
12.
Mem. Inst. Oswaldo Cruz ; 105(2): 174-178, Mar. 2010. ilus
Article de Anglais | LILACS | ID: lil-544623

RÉSUMÉ

In this study, anticoagulant activity was detected in salivary gland homogenates (SGHs) of Thyrsopelma guianense (Diptera: Simuliidae). The SGH yielded 1.07 ìg ± 0.03 (n = 15) of total soluble protein per pair of glands. In addition, following SDS-PAGE (12.5 percent gel) and silver nitrate staining, 12 polypeptides with molecular weights ranging from 14-69 kDa were detected in all physiological ages analyzed (12 h, 24 h, 48 h and 72 h following emergence). Coagulation bioassays showed that the SGHs had activities that interacted at all levels of coagulation (the intrinsic, extrinsic and common pathways), by extending the plasma recalcification time, prothrombin time, thrombin time. This is the first report on the activity of salivary gland proteins from the main vector of onchocerciasis in Brazil. We also suggest detailed studies on the morphology and function of the salivary glands in order to understand the role of these proteins in host/vector interactions.


Sujet(s)
Animaux , Femelle , Humains , Anticoagulants/pharmacologie , Protéines d'insecte/pharmacologie , Vecteurs insectes/composition chimique , Glandes salivaires/composition chimique , Simuliidae/composition chimique , Anticoagulants/isolement et purification , Brésil , Électrophorèse sur gel de polyacrylamide , Protéines d'insecte/isolement et purification , Onchocercose/transmission , Facteurs temps
13.
Acta amaz ; 37(1): 127-132, 2007. graf, tab
Article de Anglais | LILACS | ID: lil-459261

RÉSUMÉ

The sand fly Lutzomyia cruzi is considered as one of vectors of visceral leishmaniasis in Brazil. This work examined optimum feeding age, feeding time, host preference, fecundity rates, and female blood meal volume taken by single females from a closed colony of L. cruzi. Mean feeding time was longer on hamsters, 6.6 minutes, than on humans, 5.7 minutes. 49.1 percent of the 48h-old flies fed on humans and 43.3 percent of 72h-old flies fed on hamsters. Of a total of 120 females, 61 percent fed on humans and 25 percent fed on hamsters. Total fecundity was significantly higher in females fed on hamster than on human or opossum. Laboratory-reared L. cruzi females fed earlier, more promptly, and preferably on humans than on hamsters when offered these blood-meal sources simultaneously. The blood-meal volume is higher in females fed on hamsters than other hosts (human and opossum).


O flebotomíneo Lutzomyia cruzi é incriminado como um dos vetores de leishmaniose visceral no Brasil. Foram estudados: a idade ótima, a preferência alimentar, os índices de fecundidade e o volume de alimentação sanguínea realizado com fêmeas de L. cruzi colonizadas em laboratório. O tempo médio de alimentação foi maior em hamster, seguido de humano. Verificou-se que 49,1 por cento das fêmeas alimentaram-se em humano com 48h enquanto em hamster, 43,3 por cento alimentaram-se com 72h. Das 120 fêmeas observadas, 61 por cento realizaram a alimentação em humanos e 25 por cento em hamster. A fecundidade total foi maior nas fêmeas alimentadas em hamster, humano e mucura, respectivamente. Observou-se que fêmeas de L. cruzi colonizadas alimentam-se mais facilmente e preferencialmente em humanos do que em hamster quando ambas as fontes de alimentação são oferecidas simultaneamente. O volume da alimentação sanguínea foi maior nas fêmeas alimentadas em hamster.


Sujet(s)
Psychodidae , Volume sanguin , Fécondité , Maladies vectorielles , Leishmaniose viscérale
14.
Rev. bras. epidemiol ; 9(2): 186-192, jun. 2006.
Article de Portugais | LILACS | ID: lil-436830

RÉSUMÉ

A Vila de Pitinga, Presidente Figueiredo/AM, é uma área de exploração de minérios e endêmica para leishmaniose tegumentar americana (LTA). A vila é a sede administrativa e local de moradia de seus funcionários. O comportamento epidemiológico da endemia, avaliado para o período de 2000 a 2004, foi relacionado com as medidas de controle adotadas para reduzir a incidência da doença na área e comparado com o registrado para o município e o Estado do Amazonas. A maior proporção dos casos detectados no período ocorreu no gênero masculino, com atividades laborais de contato com a floresta. O declínio na incidência de casos de LTA na área do estudo, não foi observado como ocorrido no Município e Estado e foi considerado resultante das medidas de controle para a doença, aplicadas na área.


The village of Pitinga, Presidente Figueiredo, AM, is a mining area and endemic for American Cutaneous Leishmaniasis (ACL). The village is the administrative office of the mine and where mining workers live. This study presents the profile of ACL in the 2000-2004 period. The highest prevalence of ACL occurs in male individuals with forest-related activities. The reduction in the number of ACL cases in the study area was not observed in the municipality and the state, a fact probably related to the disease control measures put into practice in the area.


Sujet(s)
Humains , Mâle , Leishmaniose cutanée diffuse/épidémiologie , Leishmaniose cutanée diffuse/prévention et contrôle
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