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Mulenga A, Kim TK, Ibelli AMG. Deorphanization and target validation of cross-tick species conserved novel Amblyomma americanum tick saliva protein. Int J Parasitol 2013; 43:439-51. [PMID: 23428900 DOI: 10.1016/j.ijpara.2012.12.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/03/2012] [Accepted: 12/04/2012] [Indexed: 01/20/2023]
Abstract
We previously identified a cross-tick species conserved tick feeding stimuli responsive Amblyomma americanum (Aam) AV422 gene. This study demonstrates that AamAV422 belongs to a novel group of arthropod proteins that is characterized by 14 cysteine amino acid residues: C(23)-X7/9-C(33)-X23/24-C(58)-X8-C(67)-X7-C(75)-X23-C(99)-X15-C(115)-X10-C(126)-X24/25/33-C(150)C(151)-X7-C(159)-X8-C(168)-X23/24-C(192)-X9/10-C(202) predicted to form seven disulfide bonds. We show that AamAV422 protein is a ubiquitously expressed protein that is injected into the host within the first 24h of the tick attaching onto the host as revealed by Western blotting analyses of recombinant (r)AamAV422, tick saliva and dissected tick organ protein extracts using antibodies to 24 and 48 h tick saliva proteins. Native AamAV422 is apparently involved with mediating tick anti-hemostasis and anti-complement functions in that rAamAV422 delayed plasma clotting time in a dose responsive manner by up to ≈ 160 s, prevented platelet aggregation by up to ≈ 16% and caused ≈ 24% reduction in production of terminal complement complexes. Target validation analysis revealed that rAamAV422 is a potential candidate for a cocktail or multivalent tick vaccine preparation in that RNA interference (RNAi)-mediated silencing of AamAV422 mRNA caused a statistically significant (≈ 44%) reduction in tick engorgement weights, which is proxy for amounts of ingested blood. We speculate that AamAV422 is a potential target antigen for development of the highly desired universal tick vaccine in that consistent with high conservation among ticks, antibodies to 24h Ixodes scapularis tick saliva proteins specifically bound rAamAV422. We discuss data in this study in the context of advancing the biology of tick feeding physiology and discovery of potential target antigens for tick vaccine development.
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Affiliation(s)
- Albert Mulenga
- Texas A & M University AgriLife Research, Department of Entomology, 2475 TAMU, College Station, TX 77843, USA.
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102
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Embers ME, Narasimhan S. Vaccination against Lyme disease: past, present, and future. Front Cell Infect Microbiol 2013; 3:6. [PMID: 23407755 PMCID: PMC3569838 DOI: 10.3389/fcimb.2013.00006] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 01/20/2013] [Indexed: 12/01/2022] Open
Abstract
Lyme borreliosis is a zoonotic disease caused by Borrelia burgdorferi sensu lato bacteria transmitted to humans and domestic animals by the bite of an Ixodes spp. tick (deer tick). Despite improvements in diagnostic tests and public awareness of Lyme disease, the reported cases have increased over the past decade to approximately 30,000 per year. Limitations and failed public acceptance of a human vaccine, comprised of the outer surface A (OspA) lipoprotein of B. burgdorferi, led to its demise, yet current research has opened doors to new strategies for protection against Lyme disease. In this review we discuss the enzootic cycle of B. burgdorferi, and the unique opportunities it poses to block infection or transmission at different levels. We present the correlates of protection for this infectious disease, the pros and cons of past vaccination strategies, and new paradigms for future vaccine design that would include elements of both the vector and the pathogen.
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Affiliation(s)
- Monica E Embers
- Division of Bacteriology and Parasitology, Tulane National Primate Research Center, Covington, LA, USA.
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103
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Gulley MM, Zhang X, Michel K. The roles of serpins in mosquito immunology and physiology. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:138-47. [PMID: 22960307 PMCID: PMC3560325 DOI: 10.1016/j.jinsphys.2012.08.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/24/2012] [Accepted: 08/28/2012] [Indexed: 05/10/2023]
Abstract
In vector-borne diseases, the complex interplay between pathogen and its vector's immune system determines the outcome of infection and therefore disease transmission. Serpins have been shown in many animals to be key regulators of innate immune reactions. Their control over regulatory proteolytic cascades ultimately decides whether the recognition of a pathogen will lead to an appropriate immune response. In mosquitoes, serpins (SRPNs) regulate the activation of prophenoloxidase and thus melanization, contribute to malaria parasite lysis, and likely Toll pathway activation. Additionally, in culicine mosquitoes, SRPNs are able to regulate hemostasis in the vertebrate host, suggesting a crucial role during bloodfeeding. This review summarizes the annotation, transcriptional regulation, and current knowledge of SRPN function in the three mosquito species for which the complete genome sequence is available. Additionally, we give a brief overview of how SRPNs may be used to prevent transmission of vector-borne diseases.
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Affiliation(s)
| | | | - Kristin Michel
- Corresponding author: tel.: +1 (785) 532-0161, fax: +1 (785) 532-6653;
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Alim MA, Islam MK, Miyoshi T, Hatta T, Yamaji K, Matsubayashi M, Fujisaki K, Tsuji N. A hemocyte-derived Kunitz-BPTI-type chymotrypsin inhibitor, HlChI, from the ixodid tick Haemaphysalis longicornis, plays regulatory functions in tick blood-feeding processes. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:925-934. [PMID: 23017545 DOI: 10.1016/j.ibmb.2012.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 08/10/2012] [Accepted: 09/16/2012] [Indexed: 06/01/2023]
Abstract
Inhibitors of proteases play key roles in the biological processes of vertebrate and invertebrate animals, including arthropod parasites. Here, we describe a cDNA that encodes a functionally active chymotrypsin inhibitor of the BPTI/Kunitz family of serine protease inhibitors from the hemocytes of the ixodid tick, Haemaphysalis longicornis, herein called HlChI. HlChI sequence is evolutionarily conserved and contains six cysteine residues and three disulfide bonds with a calculated molecular weight of 9.1 kDa. HlChI-specific mRNA was expressed in all developmental stages of ticks and the expression was up-regulated by host's blood-feeding processes. Endogenous HlChI was localized mainly in the hemocytes. HlChI potently inhibited bovine pancreatic α-chymotrypsin for hydrolyzing the fluorogenic substrate (IC(50) 8.32 nM, K(d) 5.35 ± 1.01 nM) and bovine casein digestion. However, HlChI weakly inhibited bovine pancreatic trypsin and could not affect the porcine elastase activity, suggesting its narrow specificity to chymotrypsin. HlChI was stable over the pH range 2-11 and heating up to 70 °C at pH 8. HlChI was highly stable to 8 M urea and 2% SDS at pH 8.0, when treated for 24 h at 37 °C. However, 0.2 M 2-mercaptoethanol caused complete but reversible inactivation of HlChI. Knockdown of HlChI gene by RNA interference (RNAi) caused death of the feeding ticks, failure of ticks to engorge and significantly reduced body weight gain. RNAi also resulted in significantly decreased egg conversion ratio and fecundity. These results suggest that HlChI is a chymotrypsin-specific inhibitor with high stability and may play regulatory functions in host's blood-feeding processes and tick reproduction.
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Affiliation(s)
- M Abdul Alim
- Laboratory of Parasitic Diseases, National Institute of Animal Health, National Agricultural and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
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105
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Patramool S, Choumet V, Surasombatpattana P, Sabatier L, Thomas F, Thongrungkiat S, Rabilloud T, Boulanger N, Biron DG, Missé D. Update on the proteomics of major arthropod vectors of human and animal pathogens. Proteomics 2012; 12:3510-23. [DOI: 10.1002/pmic.201200300] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/13/2012] [Accepted: 10/02/2012] [Indexed: 12/12/2022]
Affiliation(s)
| | - Valérie Choumet
- Unité de Génétique Moléculaire des Bunyavirus; Institut Pasteur; Paris; France
| | | | - Laurence Sabatier
- Département des Sciences Analytiques Institut Pluridisciplinaire Hubert Curien; Strasbourg; France
| | - Frédéric Thomas
- Laboratoire MIVEGEC; UMR CNRS 5290/IRD 224/UM1; Montpellier; France
| | - Supatra Thongrungkiat
- Department of Medical Entomology; Faculty of Tropical Medicine; Mahidol University; Bangkok; Thailand
| | - Thierry Rabilloud
- CNRS UMR 5249; Chemistry and Biology of Metals; CEA; Grenoble; France
| | - Nathalie Boulanger
- EA4438 Physiopathologie et médecine translationnelle; Faculté de Pharmacie; Illkirch; France
| | - David G. Biron
- CNRS UMR 6023; Laboratoire Microorganismes: Génome et Environnement; Aubière; France
| | - Dorothée Missé
- Laboratoire MIVEGEC; UMR CNRS 5290/IRD 224/UM1; Montpellier; France
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Ronca R, Kotsyfakis M, Lombardo F, Rizzo C, Currà C, Ponzi M, Fiorentino G, Ribeiro JM, Arcà B. The Anopheles gambiae cE5, a tight- and fast-binding thrombin inhibitor with post-transcriptionally regulated salivary-restricted expression. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:610-20. [PMID: 22617725 PMCID: PMC3416949 DOI: 10.1016/j.ibmb.2012.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/12/2012] [Accepted: 04/16/2012] [Indexed: 06/01/2023]
Abstract
Mosquito saliva carries a large number of factors with anti-hemostatic, anti-inflammatory and immuno-modulatory activities. The cE5 protein was initially identified during an Anopheles gambiae salivary gland transcriptome study and later shown to share sequence similarity with anophelin, a thrombin inhibitor from the saliva of the New World mosquito Anopheles albimanus. The cE5 gene was found to encode different mRNA isoforms coexisting in several tissues of both male and female mosquitoes, a highly unusual profile for a gene potentially encoding an anti-thrombin and involved in blood feeding. Expression of the cE5 protein and assessment of its activity and inhibitory properties showed that it is a highly specific and tight-binding thrombin inhibitor, which differs from the A. albimanus orthologue for the fast-binding kinetics. Despite the widespread occurrence of cE5 transcripts in different mosquito tissues the corresponding protein was only found in female salivary glands, where it undergoes post-translational modification. Therefore, tissue-specific restriction of the A. gambiae cE5 is not achieved by transcriptional control, as common for mosquito salivary genes involved in hematophagy, but by post-trascriptional gene regulatory mechanisms. Our observations provide a paradigm of post-transcriptional regulation as key determinant of tissue specificity for a protein from an important disease vector and point out that transcriptomic data should be interpreted with caution in the absence of concomitant proteomic support.
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Affiliation(s)
- Raffaele Ronca
- Department of Structural and Functional Biology, “Federico II” University - Via Cinthia, 80126 Naples, Italy
| | - Michalis Kotsyfakis
- Institute of Parasitology, Biology Centre of the Academy of Sciences of Czech Republic, Ceske Budejovice, Czech Republic
| | - Fabrizio Lombardo
- Department of Public Health and Infectious Diseases, Sapienza University - Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Cinzia Rizzo
- Department of Public Health and Infectious Diseases, Sapienza University - Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Chiara Currà
- Dipartimento di Malattie Infettive, Parassitarie e Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Marta Ponzi
- Dipartimento di Malattie Infettive, Parassitarie e Immunomediate, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Gabriella Fiorentino
- Department of Structural and Functional Biology, “Federico II” University - Via Cinthia, 80126 Naples, Italy
| | - Josè M.C. Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Twinbrook III, 12735 Twinbrook Parkway, National Institute of Health, Rockville, MD 20852, USA
| | - Bruno Arcà
- Department of Structural and Functional Biology, “Federico II” University - Via Cinthia, 80126 Naples, Italy
- Department of Public Health and Infectious Diseases, Sapienza University - Piazzale Aldo Moro 5, 00185 Rome, Italy
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Chmelar J, Calvo E, Pedra JHF, Francischetti IMB, Kotsyfakis M. Tick salivary secretion as a source of antihemostatics. J Proteomics 2012; 75:3842-54. [PMID: 22564820 DOI: 10.1016/j.jprot.2012.04.026] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 04/13/2012] [Accepted: 04/18/2012] [Indexed: 01/04/2023]
Abstract
Ticks are mostly obligatory blood feeding ectoparasites that have an impact on human and animal health. In addition to direct damage due to feeding, some tick species serve as the vectors for the causative agents of several diseases, such as the spirochetes of the genus Borrelia causing Lyme disease, the virus of tick-borne encephalitis, various Rickettsial pathogens or even protozoan parasites like Babesia spp. Hard ticks are unique among bloodfeeders because of their prolonged feeding period that may last up to two weeks. During such a long period of blood uptake, the host develops a wide range of mechanisms to prevent blood loss. The arthropod ectoparasite, in turn, secretes saliva in the sites of bite that assists blood feeding. Indeed, tick saliva represents a rich source of proteins with potent pharmacologic action that target different mechanisms of coagulation, platelet aggregation and vasoconstriction. Tick adaptation to their vertebrate hosts led to the inclusion of a powerful protein armamentarium in their salivary secretion that has been investigated by high-throughput methods. The resulting knowledge can be exploited for the isolation of novel antihemostatic agents. Here we review the tick salivary antihemostatics and their characterized functions at the molecular and cellular levels.
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Affiliation(s)
- Jindrich Chmelar
- Division of Vascular Inflammation, Diabetes and Kidney, Department of Medicine and Institute of Physiology, Technical University Dresden, 01307 Dresden, Germany
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Tsujimoto H, Kotsyfakis M, Francischetti IMB, Eum JH, Strand MR, Champagne DE. Simukunin from the salivary glands of the black fly Simulium vittatum inhibits enzymes that regulate clotting and inflammatory responses. PLoS One 2012; 7:e29964. [PMID: 22383955 PMCID: PMC3285612 DOI: 10.1371/journal.pone.0029964] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 12/09/2011] [Indexed: 01/08/2023] Open
Abstract
Background Black flies (Diptera: Simuliidae) feed on blood, and are important vectors of Onchocerca volvulus, the etiolytic agent of River Blindness. Blood feeding depends on pharmacological properties of saliva, including anticoagulation, but the molecules responsible for this activity have not been well characterized. Methodology/Principal Findings Two Kunitz family proteins, SV-66 and SV-170, were identified in the sialome of the black fly Simulium vittatum. As Kunitz proteins are inhibitors of serine proteases, we hypothesized that SV-66 and/or −170 were involved in the anticoagulant activity of black fly saliva. Our results indicated that recombinant (r) SV-66 but not rSV-170 inhibited plasma coagulation. Mutational analysis suggested that SV-66 is a canonical BPTI-like inhibitor. Functional assays indicated that rSV66 reduced the activity of ten serine proteases, including several involved in mammalian coagulation. rSV-66 most strongly inhibited the activity of Factor Xa, elastase, and cathepsin G, exhibited lesser inhibitory activity against Factor IXa, Factor XIa, and plasmin, and exhibited no activity against Factor XIIa and thrombin. Surface plasmon resonance studies indicated that rSV-66 bound with highest affinity to elastase (KD = 0.4 nM) and to the active site of FXa (KD = 3.07 nM). We propose the name “Simukunin” for this novel protein. Conclusions We conclude that Simukunin preferentially inhibits Factor Xa. The inhibition of elastase and cathepsin G further suggests this protein may modulate inflammation, which could potentially affect pathogen transmission.
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Affiliation(s)
- Hitoshi Tsujimoto
- Department of Entomology, The University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Michail Kotsyfakis
- Laboratory of Genomics and Proteomics of Disease Vectors, Institute of Parasitology, Biology Center of the Academy of Sciences of Czech Republic, Ceske Budejovice, Czech Republic
| | - Ivo M. B. Francischetti
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jai Hoon Eum
- Department of Entomology, The University of Georgia, Athens, Georgia, United States of America
| | - Michael R. Strand
- Department of Entomology, The University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, The University of Georgia, Athens, Georgia, United States of America
| | - Donald E. Champagne
- Department of Entomology, The University of Georgia, Athens, Georgia, United States of America
- Center for Tropical and Emerging Global Diseases, The University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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A deep insight into the sialotranscriptome of the gulf coast tick, Amblyomma maculatum. PLoS One 2011; 6:e28525. [PMID: 22216098 PMCID: PMC3244413 DOI: 10.1371/journal.pone.0028525] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 11/09/2011] [Indexed: 01/10/2023] Open
Abstract
Background Saliva of blood sucking arthropods contains compounds that antagonize their hosts' hemostasis, which include platelet aggregation, vasoconstriction and blood clotting; saliva of these organisms also has anti-inflammatory and immunomodullatory properties. Perhaps because hosts mount an active immune response against these compounds, the diversity of these compounds is large even among related blood sucking species. Because of these properties, saliva helps blood feeding as well as help the establishment of pathogens that can be transmitted during blood feeding. Methodology/Principal Findings We have obtained 1,626,969 reads by pyrosequencing a salivary gland cDNA library from adult females Amblyomma maculatum ticks at different times of feeding. Assembly of this data produced 72,441 sequences larger than 149 nucleotides from which 15,914 coding sequences were extracted. Of these, 5,353 had >75% coverage to their best match in the non-redundant database from the National Center for Biotechnology information, allowing for the deposition of 4,850 sequences to GenBank. The annotated data sets are available as hyperlinked spreadsheets. Putative secreted proteins were classified in 133 families, most of which have no known function. Conclusions/Significance This data set of proteins constitutes a mining platform for novel pharmacologically active proteins and for uncovering vaccine targets against A. maculatum and the diseases they carry.
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Ma D, Assumpção TCF, Li Y, Andersen JF, Ribeiro J, Francischetti IMB. Triplatin, a platelet aggregation inhibitor from the salivary gland of the triatomine vector of Chagas disease, binds to TXA(2) but does not interact with glycoprotein PVI. Thromb Haemost 2011; 107:111-23. [PMID: 22159626 DOI: 10.1160/th11-10-0685] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 10/26/2011] [Indexed: 02/05/2023]
Abstract
Salivary glands from haematophagous animals express a notable diversity of negative modulators of platelet function. Triplatin is an inhibitor of collagen-induced platelet aggregation which has been described as an antagonist of glycoprotein VI (GPVI). Because triplatin displays sequence homology to members of the lipocalin family of proteins, we investigated whether triplatin mechanism of action could be explained by interaction with pro-haemostatic prostaglandins. Our results demonstrate that triplatin inhibits platelet aggregation induced by low doses of collagen, thromboxane A2 (TXA(2)) mimetic (U46619), and arachidonic acid (AA). On the other hand, it does not inhibit platelet aggregation by convulxin, PMA, or low-dose ADP. Isothermal titration calorimetry (ITC) revealed that triplatin binds AA, cTXA(2), TXB(2), U46619 or prostaglandin (PG)H(2) mimetic (U51605). Consistent with its ligand specificity, triplatin induces relaxation of rat aorta contracted with U46619. Triplatin also interacts with PGF(2α) and PGJ(2), but not with leukotrienes, AA or biogenic amines. Surface plasmon resonance experiments failed to demonstrate interaction of triplatin with GPVI; it also did to inhibit platelet adhesion to fibrillar or soluble collagen. Because triplatin displays sequence similarity to apolipoprotein D (ApoD) - a lipocalin associated with high-density lipoprotein, ApoD was tested as a putative TXA(2)-binding molecule. ITC failed to demonstrate binding of ApoD to all prostanoids described above, or to AA. Furthermore, ApoD was devoid of inhibitory properties towards platelets activation by AA, collagen, or U46619. In conclusion, triplatin mechanism of action has been elucidated without ambiguity as a novel TXA(2)- and PGF(2α)- binding protein. It conceivably blocks platelet aggregation and vasoconstriction, thus contributing to successful blood feeding at the vector-host interface.
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Affiliation(s)
- Dongying Ma
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland 20852, USA
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111
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Ribeiro JM, Anderson JM, Manoukis NC, Meng Z, Francischetti IM. A further insight into the sialome of the tropical bont tick, Amblyomma variegatum. BMC Genomics 2011; 12:136. [PMID: 21362191 PMCID: PMC3060141 DOI: 10.1186/1471-2164-12-136] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 03/01/2011] [Indexed: 01/02/2023] Open
Abstract
Background Ticks--vectors of medical and veterinary importance--are themselves also significant pests. Tick salivary proteins are the result of adaptation to blood feeding and contain inhibitors of blood clotting, platelet aggregation, and angiogenesis, as well as vasodilators and immunomodulators. A previous analysis of the sialotranscriptome (from the Greek sialo, saliva) of Amblyomma variegatum is revisited in light of recent advances in tick sialomes and provides a database to perform a proteomic study. Results The clusterized data set has been expertly curated in light of recent reviews on tick salivary proteins, identifying many new families of tick-exclusive proteins. A proteome study using salivary gland homogenates identified 19 putative secreted proteins within a total of 211 matches. Conclusions The annotated sialome of A. variegatum allows its comparison to other tick sialomes, helping to consolidate an emerging pattern in the salivary composition of metastriate ticks; novel protein families were also identified. Because most of these proteins have no known function, the task of functional analysis of these proteins and the discovery of novel pharmacologically active compounds becomes possible.
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Affiliation(s)
- José Mc Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20892, USA.
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