Genomes of ticks display reductions, to various extents, in genetic coding for enzymes of the haem biosynthetic pathway. Here, we mined available transcriptomes of soft tick species and identified transcripts encoding only half of the enzymes involved in haem biosynthesis. Transcripts identified across most species examined were those coding for porphobilinogen synthase, coproporphyrinogen oxidase, protoporphyrinogen oxidase, and ferrochelatase. Genomic retention of porphobilinogen synthase seems to be soft tick-restricted as no such homologue has been identified in any hard tick species. Bioinformatic mining is thus strongly indicative of the lack of biochemical capacity for de novo haem biosynthesis, suggesting a requirement for dietary haem. In the hard tick Ixodes ricinus, depletion of dietary haem, i.e. serum feeding, leads to oviposition of haem-free eggs, with no apparent embryogenesis and larvae formation. In this work, we show that serum-fed Ornithodoros moubata females, unlike those of I. ricinus, laid haem-containing eggs similarly to blood-fed controls, but only by a small proportion of the serum-fed females. To enhance the effect of dietary haem depletion, O. moubata ticks were serum-fed consecutively as last nymphal instars and females. These females laid eggs with profoundly reduced haem deposits, confirming the host origin of the haem. These data confirm the ability of soft ticks to take up and allocate host haem to their eggs in order to drive reproduction of the ticks.
- MeSH
- Argasidae * MeSH
- hem MeSH
- Ixodidae * MeSH
- Ornithodoros * MeSH
- porfobilinogensynthasa MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Introduction: We developed a new simple method to assess the composition of proteinaceous components in the saliva of Ornithodoros moubata, the main vehicle for pathogen transmission and a likely source of bioactive molecules acting at the tick-vertebrate host interface. To collect naturally expectorated saliva from the ticks we employed an artificial membrane feeding technique using a simple, chemically defined diet containing phagostimulants and submitted native saliva samples collected in this way for liquid chromatography-mass spectrometry (LC-MS) analysis. These experiments were conducted with groups of uninfected ticks as well as with O. moubata infected with B. duttonii. The ticks exhibited a fair feeding response to the tested diet with engorgement rates reaching as high as 60-100% of ticks per feeding chamber. The LC-MS analysis identified a total of 17 and 15 proteins in saliva samples from the uninfected and infected O. moubata nymphs, respectively. Importantly, the analysis was sensitive enough to detect up to 9 different proteins in the samples of saliva containing diet upon which as few as 6 nymphal ticks fed during the experiments. Some of the proteins recognized in the analysis are well known for their immunomodulatory activity in a vertebrate host, whereas others are primarily thought of as structural or "housekeeping" proteins and their finding in the naturally expectorated tick saliva confirms that they can be secreted and might serve some functions at the tick-host interface. Most notably, some of the proteins that have long been suspected for their importance in the vector-pathogen interactions of Borrelia spirochetes were detected only in the samples from infected ticks, suggesting that their expression was altered by the persistent colonization of the tick's salivary glands by spirochetes. The simple method described herein is an important addition to the toolbox available to study the vector-host-pathogen interactions in the rapidly feeding soft ticks.
- MeSH
- Argasidae * MeSH
- Borrelia * fyziologie MeSH
- Ornithodoros * MeSH
- sliny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Tick cell lines are an easy-to-handle system for the study of viral and bacterial infections and other aspects of tick cellular processes. Tick cell cultures are often continuously cultivated, as freezing can affect their viability. However, the long-term cultivation of tick cells can influence their genome stability. In the present study, we investigated karyotype and genome size of tick cell lines. Though 16S rDNA sequencing showed the similarity between Ixodes spp. cell lines at different passages, their karyotypes differed from 2n = 28 chromosomes for parental Ixodes spp. ticks, and both increase and decrease in chromosome numbers were observed. For example, the highly passaged Ixodes scapularis cell line ISE18 and Ixodes ricinus cell lines IRE/CTVM19 and IRE/CTVM20 had modal chromosome numbers 48, 23 and 48, respectively. Also, the Ornithodoros moubata cell line OME/CTVM22 had the modal chromosome number 33 instead of 2n = 20 chromosomes for Ornithodoros spp. ticks. All studied tick cell lines had a larger genome size in comparison to the genomes of the parental ticks. Thus, highly passaged tick cell lines can be used for research purposes, but possible differences in encoded genetic information and downstream cellular processes, between different cell populations, should be taken into account.
- MeSH
- Anoplura růst a vývoj účinky léků MeSH
- Argas růst a vývoj MeSH
- Ctenocephalides růst a vývoj účinky léků MeSH
- Culicidae růst a vývoj MeSH
- infestace roztoči * ošetřování přenos prevence a kontrola MeSH
- klíště růst a vývoj účinky léků MeSH
- komáří přenašeči klasifikace patogenita účinky léků MeSH
- kousnutí a bodnutí hmyzem ošetřování prevence a kontrola MeSH
- kousnutí klíštětem prevence a kontrola MeSH
- lidé MeSH
- Pediculus růst a vývoj účinky léků MeSH
- roztoči anatomie a histologie klasifikace patogenita MeSH
- Sarcoptes scabiei růst a vývoj MeSH
- štěnice růst a vývoj MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Anaphylaxis is a serious systemic allergic reaction with rapid onset and potentially life-threatening. We report in detail a case of severe nocturnal anaphylaxis due to pigeon tick bite showing the diagnostic value of the extract and the recombinant allergen in the diagnostic procedures (basophil activation test, IgE immunoblot, and experimental ImmunoCAP). Apart from the presented case, we describe that during the last 10 years, we have collected 28 cases of allergy to Argas reflexus from several European countries. We suspect that this allergy is underdiagnosed because of the lack of diagnostic reagents. Because of the growing number of pigeons in Middle and Southern Europe cities, some cases of idiopathic anaphylaxis could potentially be caused by A. reflexus in those countries. The identification of pigeon ticks as a trigger of anaphylaxis would greatly improve medical care and advice for these patients as the parasite can be exterminated by eradication measures to avoid further incidents.
- MeSH
- anafylaxe diagnóza etiologie MeSH
- Argas MeSH
- Columbidae parazitologie MeSH
- dospělí MeSH
- imunoglobulin E analýza imunologie MeSH
- kousnutí klíštětem komplikace imunologie MeSH
- lidé MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
In the last two decades, the advent of molecular methods has revealed a remarkable diversity of rickettsiae (Rickettsiales: Rickettsiaceae) in invertebrates. Several species of these obligate intracellular bacteria are known to cause human infections, hence more attention has been directed towards human-biting ectoparasites. A spotted fever group Rickettsia sp. was previously detected in Ixodes lividus ticks (Ixodidae) associated with sand martins (Hirundinidae: Riparia riparia). In order to identify whether this rickettsia varies among isolated tick populations, a total of 1758 I. lividus ticks and five Ixodes ricinus ticks (Ixodidae) were collected in the Czech Republic and 148 I. lividus ticks were collected in Belgium, from nests of sand martins, European bee-eaters (Meropidae: Merops apiaster), Eurasian tree sparrows (Passeridae: Passer montanus), and from captured sand martins. We screened 165 and 78 I. lividus ticks (from the Czech Republic and Belgium, respectively) and all five I. ricinus ticks for the presence of rickettsial DNA. Only I. lividus samples were positive for Rickettsia vini, a spotted fever group rickettsia that commonly infects the tree-hole tick Ixodes arboricola (Ixodidae). Maximum likelihood analysis of the rickettsial sequences showed that the most closely related organism to R. vini corresponds to an uncharacterized rickettsia detected in Argas lagenoplastis (Argasidae), a nidicolous soft tick of the fairy martin (Hirundinidae: Petrochelidon ariel) in Australia. The observed variability of R. vini sequences from isolated tick populations was low; all 85 sequenced samples were identical to each other in five out of six partial rickettsial genes, except for the sca4 sequence (99.9% identity, 808/809 nt) that differed in I. lividus ticks from two sampling sites in the Czech Republic.
- MeSH
- Argasidae mikrobiologie MeSH
- DNA bakterií genetika MeSH
- fylogeneze MeSH
- infestace klíšťaty epidemiologie veterinární MeSH
- klíště mikrobiologie MeSH
- koevoluce genetika MeSH
- lidé MeSH
- nemoci ptáků mikrobiologie MeSH
- nymfa MeSH
- pravděpodobnostní funkce MeSH
- ptáci parazitologie MeSH
- Rickettsia klasifikace genetika izolace a purifikace MeSH
- rickettsiové infekce epidemiologie mikrobiologie veterinární MeSH
- skvrnité horečky epidemiologie mikrobiologie veterinární MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Belgie epidemiologie MeSH
- Česká republika epidemiologie MeSH
Bacterial endosymbionts of ticks are of interest due to their close evolutionary relationships with tick-vectored pathogens. For instance, whereas many ticks contain Francisella-like endosymbionts (FLEs), others transmit the mammalian pathogen Francisella tularensis. We recently sequenced the genome of an FLE present in the hard tick Amblyomma maculatum (FLE-Am) and showed that it likely evolved from a pathogenic ancestor. In order to expand our understanding of FLEs, in the current study we sequenced the genome of an FLE in the soft tick Ornithodoros moubata and compared it to the genomes of FLE-Am, Francisella persica-an FLE in the soft tick Argus (Persicargas) arboreus, Francisella sp. MA067296-a clinical isolate responsible for an opportunistic human infection, and F. tularensis, the established human pathogen. We determined that FLEs and MA067296 belonged to a sister taxon of mammalian pathogens, and contained inactivated versions of virulence genes present in F. tularensis, indicating that the most recent common ancestor shared by FLEs and F. tularensis was a potential mammalian pathogen. Our analyses also revealed that the two soft ticks (O. moubata and A. arboreus) probably acquired their FLEs separately, suggesting that the virulence attenuation observed in FLEs are not the consequence of a single acquisition event followed by speciation, but probably due to independent transitions of pathogenic francisellae into nonpathogenic FLEs within separate tick lineages. Additionally, we show that FLEs encode intact pathways for the production of several B vitamins and cofactors, denoting that they could function as nutrient-provisioning endosymbionts in ticks.
- MeSH
- Argasidae mikrobiologie fyziologie MeSH
- bakteriální geny MeSH
- biologická evoluce MeSH
- faktory virulence genetika MeSH
- Francisella genetika izolace a purifikace fyziologie MeSH
- fylogeneze MeSH
- gramnegativní bakteriální infekce mikrobiologie MeSH
- lidé MeSH
- symbióza * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
To ensure successful feeding tick saliva contains a number of inhibitory proteins that interfere with the host immune response and help to create a permissive environment for pathogen transmission. Among the potential targets of the salivary cystatins are two host cysteine proteases, cathepsin S, which is essential for antigen- and invariant chain-processing, and cathepsin C (dipeptidyl peptidase 1, DPP1), which plays a critical role in processing and activation of the granule serine proteases. Here, the effect of salivary cystatin OmC2 fromOrnithodoros moubatawas studied using differentiated MUTZ-3 cells as a model of immature dendritic cells of the host skin. Following internalization, cystatin OmC2 was initially found to inhibit the activity of several cysteine cathepsins, as indicated by the decreased rates of degradation of fluorogenic peptide substrates. To identify targets, affinity chromatography was used to isolate His-tagged cystatin OmC2 together with the bound proteins from MUTZ-3 cells. Cathepsins S and C were identified in these complexes by mass spectrometry and confirmed by immunoblotting. Furthermore, reduced increase in the surface expression of MHC II and CD86, which are associated with the maturation of dendritic cells, was observed. In contrast, human inhibitor cystatin C, which is normally expressed and secreted by dendritic cells, did not affect the expression of CD86. It is proposed that internalization of salivary cystatin OmC2 by the host dendritic cells targets cathepsins S and C, thereby affecting their maturation.
- MeSH
- antigeny CD86 MeSH
- antigeny diferenciační B-lymfocytární MeSH
- buněčné linie MeSH
- cystatiny metabolismus MeSH
- dendritické buňky imunologie metabolismus MeSH
- epoxidové sloučeniny imunologie metabolismus MeSH
- geny MHC třídy II imunologie MeSH
- kathepsin C metabolismus MeSH
- kathepsiny chemie imunologie metabolismus MeSH
- klíšťata enzymologie MeSH
- lidé MeSH
- lyzozomy enzymologie MeSH
- MHC antigeny II. třídy MeSH
- Ornithodoros enzymologie MeSH
- rekombinantní proteiny MeSH
- sliny enzymologie MeSH
- tyrosin analogy a deriváty imunologie metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Fibrinogen-related proteins with lectin activity are believed to be part of the tick innate immune system. Several fibrinogen-related proteins have been described and characterised mainly on the basis of their cDNA sequences while direct biochemical evidence is missing. One of them, the haemolymph lectin Dorin M from the tick Ornithodoros moubata was isolated and characterised in more depth. RESULTS: Several fibrinogen-related proteins were detected in the haemolymph of ixodid ticks Dermacentor marginatus, Rhipicephalus appendiculatus, R. pulchellus, and R. sanguineus. These proteins were recognised by sera directed against the tick lectin Dorin M and the haemagglutination activity of the ticks R. appendiculatus and D. marginatus. Cross-reactivity of the identified proteins with antibodies against the fibrinogen domain of the human ficolin was also shown. The carbohydrate-binding ability of tick haemolymph was confirmed by haemagglutination activity assays, and this activity was shown to be inhibited by neuraminic acid and sialylated glycoproteins as well as by N-acetylated hexosamines. The fibrinogen-related proteins were shown to be glycosylated and they were localised in salivary glands, midguts, and haemocytes of D. marginatus. Hemelipoglycoprotein was also recognised by sera directed against the fibrinogen-related proteins in all three Rhipicephalus species as well as in D. marginatus. However, this protein does not contain the fibrinogen domain and thus, the binding possibly results from the structure similarity between hemelipoglycoprotein and the fibrinogen domain. CONCLUSIONS: The presence of fibrinogen-related proteins was shown in the haemolymph of four tick species in high abundance. Reactivity of antibodies directed against ficolin or fibrinogen-related proteins with proteins which do not contain the fibrinogen domain points out the importance of sequence analysis of the identified proteins in further studies. Previously observed expression of fibrinogen-related proteins in haemocytes together with the results of this study suggest involvement of fibrinogen-related proteins in tick immunity processes. Thus, they have potential as targets for anti-tick vaccines and as antimicrobial proteins in pharmacology. Research on fibrinogen-related proteins could reveal further details of tick innate immunity processes.
- MeSH
- anatomické struktury zvířat chemie MeSH
- Dermacentor chemie MeSH
- fibrinogen imunologie MeSH
- glykoproteiny imunologie metabolismus MeSH
- hemaglutininy imunologie metabolismus MeSH
- hmyzí proteiny imunologie metabolismus MeSH
- lektiny imunologie metabolismus MeSH
- lidé MeSH
- metabolismus sacharidů MeSH
- Ornithodoros chemie MeSH
- protilátky imunologie MeSH
- Rhipicephalus chemie MeSH
- vazba proteinů MeSH
- zkřížené reakce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- Acari klasifikace růst a vývoj MeSH
- Argasidae klasifikace růst a vývoj MeSH
- Chiroptera parazitologie MeSH
- infestace ektoparazity epidemiologie parazitologie veterinární MeSH
- infestace roztoči epidemiologie parazitologie MeSH
- interakce hostitele a parazita MeSH
- prevalence MeSH
- roztoči klasifikace růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Geografické názvy
- Polsko MeSH
