8 results on '"Tirloni, Lucas"'
Search Results
2. Coxiella endosymbiont of Rhipicephalus microplus modulates tick physiology with a major impact in blood feeding capacity
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Guizzo, Melina Garcia, Tirloni, Lucas, Gonzalez, Sergio Alberto, Farber, Marisa Diana, Braz, Glória Regina Cardoso, Parizi, Luis Fernando, Silva, Lucas André Dedavid e, Vaz Junior, Itabajara da Silva, and Oliveira, Pedro Lagerblad de
- Subjects
Transcriptoma ,Coxiella ,Rhipicephalus microplus ,Alimentação hematófaga ,Crescimento e desenvolvimento ,Microbiome ,Simbiose ,Symbiont ,Transcriptome ,Tick - Abstract
In the past decade, metagenomics studies exploring tick microbiota have revealed widespread interactions between bacteria and arthropods, including symbiotic interactions. Functional studies showed that obligate endosymbionts contribute to tick biology, affecting reproductive fitness and molting. Understanding the molecular basis of the interaction between ticks and their mutualist endosymbionts may help to develop control methods based on microbiome manipulation. Previously, we showed that Rhipicephalus microplus larvae with reduced levels of Coxiella endosymbiont of R. microplus (CERM) were arrested at the metanymph life stage (partially engorged nymph) and did not molt into adults. In this study, we performed a transcriptomic differential analysis of the R. microplus metanymph in the presence and absence of its mutualist endosymbiont. The lack of CERM resulted in an altered expression profile of transcripts from several functional categories. Gene products such as DA-P36, protease inhibitors, metalloproteases, and evasins, which are involved in blood feeding capacity, were underexpressed in CERM-free metanymphs. Disregulation in genes related to extracellular matrix remodeling was also observed in the absence of the symbiont. Taken together, the observed alterations in gene expression may explain the blockage of development at the metanymph stage and reveal a novel physiological aspect of the symbiont-tick-vertebrate host interaction.
- Published
- 2022
3. Tick-host range adaptation : changes in protein profiles in unfed adult Ixodes scapularis and Amblyomma americanum saliva stimulated to feed on different hosts
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Tirloni, Lucas, Kim, Tae Kwon, Pinto, Antonio Frederico Michel, Yates III, John R., Vaz Junior, Itabajara da Silva, and Mulenga, Albert
- Subjects
Proteômica ,Genética molecular ,Ixodes scapularis ,Tick-host relationship ,Proteínas ,Hospedeiro ,Proteomic ,Amblyomma americanum ,Saliva ,Carrapato ,Host adaptation ,Tick - Abstract
Understanding the molecular basis of how ticks adapt to feed on different animal hosts is central to understanding tick and tick-borne disease (TBD) epidemiology. There is evidence that ticks differentially express specific sets of genes when stimulated to start feeding. This study was initiated to investigate if ticks such as Ixodes scapularis and Amblyomma americanum that are adapted to feed on multiple hosts utilized the same sets of proteins to prepare for feeding. We exposed I. scapularis and A. americanum to feeding stimuli of different hosts (rabbit, human, and dog) by keeping unfed adult ticks enclosed in a perforated microfuge in close contact with host skin, but not allowing ticks to attach on host. Our data suggest that ticks of the same species differentially express tick saliva proteins (TSPs) when stimulated to start feeding on different hosts. SDS-PAGE and silver staining analysis revealed unique electrophoretic profiles in saliva of I. scapularis and A. americanum that were stimulated to feed on different hosts: rabbit, human, and dog. LC-MS/MS sequencing and pairwise analysis demonstrated that I. scapularis and A. americanum ticks expressed unique protein profiles in their saliva when stimulated to start feeding on different hosts: rabbit, dog, or human. Specifically, our data revealed TSPs that were unique to each treatment and those that were shared between treatments. Overall, we identified a total of 276 and 340 non-redundant I. scapularis and A. americanum TSPs, which we have classified into 28 functional classes including: secreted conserved proteins (unknown functions), proteinase inhibitors, lipocalins, extracellularmatrix/cell adhesion, heme/ironmetabolism, signal transduction and immunity-related proteins being the most predominant in saliva of unfed ticks. With exception of research on vaccines against Rhipicephalus microplus, which its natural host, cattle, research on vaccine against other ticks relies feeding ticks on laboratory animals. Data here suggest that relying on lab animal tick feeding data to select target antigens could result in prioritizing irrelevant anti-tick vaccine targets that are expressed when ticks feed on laboratory animals. This study provides the platform that could be utilized to identify relevant target anti-tick vaccine antigens, and will facilitate early stage tick feeding research.
- Published
- 2017
4. Stable internal reference genes for quantitative RT-PCR analyses in Rhipicephalus microplus during embryogenesis.
- Author
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Kim, Tae Kwon, Waldman, Jéssica, Ibanez-Carrasco, Freddy, Tirloni, Lucas, Waltero, Camila, Calixo, Christiano, Braz, Gloria R., Mulenga, Albert, da Silva Vaz Junior, Itabajara, and Logullo, Carlos
- Abstract
Studies on the transcriptional control of gene expression are crucial to understand changes in organism's physiological or cellular conditions. To obtain reliable data on mRNA amounts and the estimation of gene expression levels, it is crucial to normalize the target gene with one or more internal reference gene(s). However, the use of constitutive genes as reference genes is controversial, as their expression patterns are sometimes more complex than previously thought. In various arthropod vectors, including ticks, several constitutive genes have been identified by studying gene expression in different tissues and life stages. The cattle tick Rhipicephalus microplus is a major vector for several pathogens and is widely distributed in tropical and subtropical regions globally. Tick developmental physiology is an essential aspect of research, particularly embryogenesis, where many important developmental events occur, thus the identification of stable reference genes is essential for the interpretation of reliable gene expression data. This study aimed to identify and select R. microplus housekeeping genes and evaluate their stability during embryogenesis. Reference genes used as internal control in molecular assays were selected based on previous studies. These genes were screened by quantitative PCR (qPCR) and tested for gene expression stability during embryogenesis. Results demonstrated that the relative stability of reference genes varied at different time points during the embryogenesis. The GeNorm tool showed that elongation factor 1α (Elf1a) and ribosomal protein L4 (Rpl4) were the most stable genes, while H3 histone family 3A (Hist3A) and ribosomal protein S18 (RpS18) were the least stable. The NormFinder tool showed that Rpl4 was the most stable gene, while the ranking of Elf1a was intermediate in all tested conditions. The BestKeeper tool showed that Rpl4 and cyclophilin A (CycA) were the more and less stable genes, respectively. These data collectively demonstrate that Rpl4, Elf1a , and GAPDH are suitable internal controls for normalizing qPCR during R. microplus embryogenesis. These genes were consistently identified as the most stable in various analysis methods employed in this study. Thus, findings presented in this study offer valuable information for the study of gene expression during embryogenesis in R. microplus. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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5. Blood anticlotting activity of a Rhipicephalus microplus cathepsin L-like enzyme.
- Author
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Xavier, Marina Amaral, Tirloni, Lucas, Torquato, Ricardo, Tanaka, Aparecida, Pinto, Antônio F.M., Diedrich, Jolene K., Yates III, John R., da Silva Vaz, Itabajara, Seixas, Adriana, and Termignoni, Carlos
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CATHEPSINS , *ENZYMES , *ANTITHROMBINS , *THROMBIN , *BLOOD , *BLOOD platelet aggregation - Abstract
In parasites, cathepsins are implicated in mechanisms related to organism surveillance and host evasion. Some parasite cathepsins have fibrinogenolytic and fibrinolytic activity, suggesting that they may contribute to maintain blood meal fluidity for extended feeding periods. Here, it is shown that BmGTI (Rhipicephalus [Boophilus] microplus Gut Thrombin Inhibitor), a protein previously described as an inhibitor of fibrinogen hydrolysis and platelet aggregation by thrombin, and BmCL1 (Rhipicephalus [Boophilus] microplus Cathepsin-L like 1) are the same protein, hereinafter referred to using the earliest name (BmCL1). To further characterize BmCL1, Rhipicephalus microplus native and recombinant (rBmCL1) proteins were obtained. Native BmCL1 was isolated using thrombin-affinity chromatography, and it displays thrombin inhibition activity. We subsequently investigated rBmCL1 interaction with thrombin. We show that rBmCL1 and thrombin have a dissociation constant (Κ D) of 130.2 ± 11.2 nM, and this interaction likely occurs due to a more electronegative surface of BmCL1 at pH 7.5 than at pH 5.0, which may favor an electrostatic binding to positively charged thrombin exosites. During BmCL1-thrombin interaction, thrombin is not degraded or inhibited. rBmCL1 impairs thrombin-induced fibrinogen clotting via a fibrinogenolytic activity. Fibrinogen degradation by BmCL1 occurs by the hydrolysis of Aα- and Bβ-chains, generating products similar to those produced by fibrinogenolytic cathepsins from other organisms. In conclusion, BmCL1 likely has an additional role in R. microplus blood digestion, besides its role in hemoglobin degradation at acid pH. BmCL1 fibrinogenolytic activity indicates a proteolytic activity in the neutral lumen of tick midgut, contributing to maintain the fluidity of the ingested blood, which remains to be confirmed in vivo. • BmGTI (tick thrombin inhibitor) and BmCL1 (tick cathepsin) are the same protein. • There is an interaction between rBmCL1 and thrombin, but no degradation. • rBmCL1 have fibrinogenolytic activity. • rBmCL1 degrades fibrinogen Aα- and Bβ-chains. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
6. Tick Gené's organ engagement in lipid metabolism revealed by a combined transcriptomic and proteomic approach.
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Xavier, Marina Amaral, Tirloni, Lucas, Pinto, Antonio F.M., Diedrich, Jolene K., Yates III, John R., Gonzales, Sergio, Farber, Marisa, da Silva Vaz, Itabajara, and Termignoni, Carlos
- Abstract
Lipids play key roles in arthropod metabolism. In ticks, these biomolecules are transported from fat body to other organs, such as ovary and Gené's organ. Gené's organ, an apparatus found exclusively in female ticks, secretes a protective wax coat onto the egg surface, increasing egg viability in the environment due to waterproof, cohesive, and antimicrobial properties. In this work, a combined transcriptomic and proteomic approach shows that Gené's organ not solely secrets compounds taken up from the hemolymph, but is actively engaged in synthesis, modification, and oxidation of lipids. Gené's organ was analyzed at two distinct stages: 1) when ticks detach from host by the end of hematophagous phase, and 2) during egg-laying. Data show that Gené's organ undergoes a maturation process before the onset of oviposition, in preparation for its role during egg-laying. Because it deals with a wax-secreting organ, the study focused on lipid metabolism, examining a full machinery to synthesize, modify, and oxidize fatty acids. Proteins involved in sterol modification, transport, and degradation were also addressed. In addition to highlighting Gené's organ importance in tick reproductive physiology, the results reveal proteins and pathways crucial to egg wax secretion, and consequently, egg development in the environment. Tools targeting these molecules and pathways would impair egg viability in the environment, and therefore have the potential to be developed into novel tick control methods. [ABSTRACT FROM AUTHOR]
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- 2019
- Full Text
- View/download PDF
7. Saliva from nymph and adult females of Haemaphysalis longicornis: a proteomic study.
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Tirloni, Lucas, Islam, Mohammad Saiful, Tae Kwon Kim, Diedrich, Jolene K., Yates III, John R., Pinto, Antônio F. M., Mulenga, Albert, Myung-Jo You, and Da Silva Vaz Jr., Itabajara
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TICKS , *PROTEOMICS , *SALIVA , *HAEMAPHYSALIS longicornis , *ANAPLASMA phagocytophilum , *COXIELLA burnetii - Abstract
Background: Haemaphysalis longicornis is a major vector of Theileria spp., Anaplasma phagocytophilum, Babesia spp. and Coxiella burnetti in East Asian countries. All life stages of ixodid ticks have a destructive pool-feeding style in which they create a pool-feeding site by lacerating host tissue and secreting a variety of biologically active compounds that allows the tick to evade host responses, enabling the uptake of a blood meal. The identification and functional characterization of tick saliva proteins can be useful to elucidate the molecular mechanisms involved in tick development and to conceive new anti-tick control methods. Methods: H. longicornis tick saliva was collected from fully engorged nymphs and fully engorged adults induced by dopamine or pilocarpine, respectively. Saliva was digested with trypsin for LC-MS/MS sequencing and peptides were searched against tick and rabbit sequences. Results: A total of 275 proteins were identified, of which 135 were tick and 100 were rabbit proteins. Of the tick proteins, 30 proteins were identified exclusively in fully engorged nymph saliva, 74 in fully engorged adult females, and 31 were detected in both stages. The identified tick proteins include heme/iron metabolism-related proteins, oxidation/detoxification proteins, enzymes, proteinase inhibitors, tick-specific protein families, and cytoskeletal proteins. Proteins involved in signal transduction, transport and metabolism of carbohydrate, energy, nucleotide, amino acids and lipids were also detected. Of the rabbit proteins, 13 were present in nymph saliva, 48 in adult saliva, and 30 were present in both. The host proteins include immunoglobulins, complement system proteins, antimicrobial proteins, serum albumin, peroxiredoxin, serotransferrin, apolipoprotein, hemopexin, proteinase inhibitors, and hemoglobin/red blood cells-related products. Conclusions: This study allows the identification of H. longicornis saliva proteins. In spontaneously detached tick saliva various proteins were identified, although results obtained with saliva of fully engorged ticks need to be carefully interpreted. However, it is interesting to note that proteins identified in this study were also described in other tick saliva proteomes using partially engorged tick saliva, including hemelipoprotein, proteases, protease inhibitors, proteins related to structural functions, transporter activity, metabolic processes, and others. In conclusion, these data can provide a deeper understanding to the biology of H. longicornis. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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8. A family of serine protease inhibitors (serpins) in the cattle tick Rhipicephalus (Boophilus) microplus.
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Tirloni, Lucas, Seixas, Adriana, Mulenga, Albert, da Silva Vaz, Itabajara, and Termignoni, Carlos
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SERINE proteinase inhibitors , *CATTLE tick , *RHIPICEPHALUS , *NUCLEOTIDE sequence , *SERPINS , *CONSERVED sequences (Genetics) - Abstract
Highlights: [•] Eighteen full-length serpin sequences were found in Rhipicephalus (Boophilus) microplus. [•] R. microplus serpins are conserved across other tick serpins. [•] Genes are differentially expressed in analysed tissues. [•] Tick serpins possesses a serpin conserved tertiary structure. [Copyright &y& Elsevier]
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- 2014
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