Tick development
Dotaz
Zobrazit nápovědu
The tick-borne encephalitis virus (TBEV) causes a most important viral life-threatening illness transmitted by ticks. The interactions between the virus and ticks are largely unexplored, indicating a lack of experimental tools and systematic studies. One such tool is recombinant reporter TBEV, offering antibody-free visualization to facilitate studies of transmission and interactions between a tick vector and a virus. In this paper, we utilized a recently developed recombinant TBEV expressing the reporter gene mCherry to study its fitness in various tick-derived in vitro cell cultures and live unfed nymphal Ixodes ricinus ticks. The reporter virus was successfully replicated in tick cell lines and live ticks as confirmed by the plaque assay and the mCherry-specific polymerase chain reaction (PCR). Although a strong mCherry signal determined by fluorescence microscopy was detected in several tick cell lines, the fluorescence of the reporter was not observed in the live ticks, corroborated also by immunoblotting. Our data indicate that the mCherry reporter TBEV might be an excellent tool for studying TBEV-tick interactions using a tick in vitro model. However, physiological attributes of a live tick, likely contributing to the inactivity of the reporter, warrant further development of reporter-tagged viruses to study TBEV in ticks in vivo.
Klíšťová encefalitida je v našich podmínkách jednou z nejdůležitějších a nejzávažnějších infekcí centrálního nervového systému člověka. Navzdory medicínskému významu této choroby o ní však víme stále velmi málo. Nedostatečně prozkoumaná zůstává především patogeneze klíšťové encefalitidy. Nově se objevují práce, které poukazují na význam imunopatologických reakcí při encefalitidách způsobených flaviviry, včetně klíšťové encefalitidy. Kromě toho se ukazuje, že samotný průběh klíšťové encefalitidy je ovlivněn řadou faktorů, mezi které patří například i genotyp pacienta. Cílem tohoto přehledového článku je poukázat na tyto nové poznatky, které zásadním způsobem mění náš dosavadní pohled na toto závažné onemocnění.
In Europe, tick-borne encephalitis represents one of the most important and serious infections of the central nervous system of humans. Despite the medical importance of this disease, pathogenesis of tick-borne encephalitis remains largely unknown. Recently, several reports indicate the importance of immunopathology during the development of encephalitides caused by flaviviruses, including tick-borne encephalitis. The development of the infection is, however, influenced by several factors, including host genotype. The goal of this review is to summarize these new data that change our understanding of this important human disease.
- Klíčová slova
- virus klíšťové encefalitidy, imunopatologie,
- MeSH
- dítě MeSH
- dospělí MeSH
- klíšťová encefalitida * diagnóza epidemiologie etiologie imunologie prevence a kontrola přenos terapie virologie MeSH
- lidé MeSH
- rizikové faktory MeSH
- senioři MeSH
- vakcinace metody MeSH
- viry klíšťové encefalitidy patogenita růst a vývoj ultrastruktura MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- senioři MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
The carbohydrate Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) is produced in all mammals except for humans, apes and old world monkeys that lost the ability to synthetize this carbohydrate. Therefore, humans can produce high antibody titers against α-Gal. Anti-α-Gal IgE antibodies have been associated with tick-induced allergy (i.e. α-Gal syndrome) and anti-α-Gal IgG/IgM antibodies may be involved in protection against malaria, leishmaniasis and Chagas disease. The α-Gal on tick salivary proteins plays an important role in the etiology of the α-Gal syndrome. However, whether ticks are able to produce endogenous α-Gal remains currently unknown. In this study, the Ixodes scapularis genome was searched for galactosyltransferases and three genes were identified as potentially involved in the synthesis of α-Gal. Heterologous gene expression in α-Gal-negative cells and gene knockdown in ticks confirmed that these genes were involved in α-Gal synthesis and are essential for tick feeding. Furthermore, these genes were shown to play an important role in tick-pathogen interactions. Results suggested that tick cells increased α-Gal levels in response to Anaplasma phagocytophilum infection to control bacterial infection. These results provided the molecular basis of endogenous α-Gal production in ticks and suggested that tick galactosyltransferases are involved in vector development, tick-pathogen interactions and possibly the etiology of α-Gal syndrome in humans.
- MeSH
- alfa-galaktosidasa genetika metabolismus MeSH
- Anaplasma phagocytophilum patogenita MeSH
- ehrlichióza genetika metabolismus MeSH
- galaktosyltransferasy metabolismus MeSH
- genom genetika MeSH
- HL-60 buňky MeSH
- infekce přenášené vektorem MeSH
- interakce hostitele a patogenu genetika MeSH
- klíště mikrobiologie MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- proteiny členovců metabolismus MeSH
- sekvence aminokyselin MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Similarly to other blood-feeding arthropods, ticks have evolved immunosuppressive mechanisms enabling them to overcome the host immune system. Although the immunomodulatory effect of tick saliva on several cell populations of the immune system has been extensively studied, little is known about its impact on dendritic cells (DCs). We have examined the effect of Ixodes ricinus tick saliva on DC function in vitro and in vivo. Exposure of DCs to tick saliva in vitro resulted in impaired maturation, upon CD40 or TLR9, TLR3 and TLR7 ligation, as well as reduced Ag presentation capacity. Administration of tick saliva in vivo significantly inhibited maturation and early migration of DCs from inflamed skin to draining lymph nodes, and decreased the capacity of lymph node DCs to present soluble Ag to specific T cells. Moreover, saliva-exposed DCs failed to induce efficient Th1 and Th17 polarization and promoted development of Th2 responses. Our data reveal a complex inhibitory effect exerted by tick saliva on DC function. Given the role of DCs as the key instigators of adaptive immune responses, alteration of their function might represent a major mechanism of tick-mediated immune evasion.
- MeSH
- antigeny CD40 imunologie MeSH
- dendritické buňky imunologie MeSH
- financování organizované MeSH
- imunologická tolerance imunologie MeSH
- klíště imunologie MeSH
- lymfatické uzliny imunologie MeSH
- myši MeSH
- pohyb buněk imunologie MeSH
- prezentace antigenu imunologie MeSH
- sliny imunologie MeSH
- Th1 buňky imunologie MeSH
- Th2 buňky imunologie MeSH
- toll-like receptory imunologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
Ticks and the pathogens they transmit constitute a growing burden for human and animal health worldwide. Vector competence is a component of vectorial capacity and depends on genetic determinants affecting the ability of a vector to transmit a pathogen. These determinants affect traits such as tick-host-pathogen and susceptibility to pathogen infection. Therefore, the elucidation of the mechanisms involved in tick-pathogen interactions that affect vector competence is essential for the identification of molecular drivers for tick-borne diseases. In this review, we provide a comprehensive overview of tick-pathogen molecular interactions for bacteria, viruses, and protozoa affecting human and animal health. Additionally, the impact of tick microbiome on these interactions was considered. Results show that different pathogens evolved similar strategies such as manipulation of the immune response to infect vectors and facilitate multiplication and transmission. Furthermore, some of these strategies may be used by pathogens to infect both tick and mammalian hosts. Identification of interactions that promote tick survival, spread, and pathogen transmission provides the opportunity to disrupt these interactions and lead to a reduction in tick burden and the prevalence of tick-borne diseases. Targeting some of the similar mechanisms used by the pathogens for infection and transmission by ticks may assist in development of preventative strategies against multiple tick-borne diseases.
- MeSH
- arachnida jako vektory mikrobiologie parazitologie virologie MeSH
- interakce hostitele a patogenu * MeSH
- klíšťata mikrobiologie parazitologie fyziologie virologie MeSH
- lidé MeSH
- nemoci přenášené klíšťaty epidemiologie MeSH
- přenos infekční nemoci * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
O priebehu kliešťovej encefalitídy (KE) v gravidite, ako aj o riziku vertikálneho prenosu je v literatúre len veľmi málo informácií. V prá- ci predkladáme kazuistiku pacientky, ktorá ochorela na KE v 37. týždni gravidity alimentárnou cestou. Ochorenie u nej prebehlo pod obrazom meningitídy, bez neurologického poškodenia. Tri týždne po vypuknutí ochorenia porodila zdravé dieťa, ktoré vo veku 2 a pol roka malo negatívny výsledok protilátok proti KE obidvoch tried IgM aj IgG a počas celého obdobia sledovania u neho neboli zazna- menané žiadne známky neurologického poškodenia, či narušený psychomotorický vývin.
There is a lack of information in the literature about the course and risk of vertical transmission of tick-borne encephalitis (TBE) during pregnancy. Presented is a case report of a female patient in the 37 th week of pregnancy infected by foodborne transmission. She developed meningitis with no neurological damage. Three weeks after the first symptoms, she gave birth to a healthy child who, at the age of 30 months, had a negative result of anti-TBE antibodies in both IgM and IgG classes. In the child, no signs of neurolo- gical injury or impaired psychomotor development were observed throughout the follow-up period.
- MeSH
- dospělí MeSH
- infekční komplikace v těhotenství * MeSH
- klíšťová encefalitida diagnóza terapie MeSH
- komplikace těhotenství MeSH
- lidé MeSH
- meningoencefalitida * diagnóza terapie MeSH
- porod MeSH
- těhotenství MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
Arthropods are dangerous vectors of agents of deadly diseases, which may hit as epidemics or pandemics in the increasing world population of humans and animals. Among them, ticks transmit more pathogen species than any other group of blood-feeding arthropods worldwide. Thus, the effective and eco-friendly control of tick vectors in a constantly changing environment is a crucial challenge. A number of novel routes have been attempted to prevent and control tick-borne diseases, including the development of (i) vaccines against viruses vectored by ticks; (ii) pheromone-based control tools, with special reference to the "lure and kill" techniques; (iii) biological control programmes relying on ticks' natural enemies and pathogens; and (iv) the integrated pest management practices aimed at reducing tick interactions with livestock. However, the extensive employment of acaricides and tick repellents still remains the two most effective and ready-to-use strategies. Unfortunately, the first one is limited by the rapid development of resistance in ticks, as well as by serious environmental concerns. On the other hand, the exploitation of plants as sources of effective tick repellents is often promising. Here, we reviewed current knowledge concerning the effectiveness of plant extracts as acaricides or repellents against tick vectors of public health importance, with special reference to Ixodes ricinus, Ixodes persulcatus, Amblyomma cajennense, Haemaphysalis bispinosa, Haemaphysalis longicornis, Hyalomma anatolicum, Hyalomma marginatum rufipes, Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) microplus, Rhipicephalus pulchellus, Rhipicephalus sanguineus and Rhipicephalus turanicus. Eighty-three plant species from 35 botanical families were selected. The most frequent botanical families exploited as sources of acaricides and repellents against ticks were Asteraceae (15 % of the selected studies), Fabaceae (9 %), Lamiaceae (10 %), Meliaceae (5 %), Solanaceae (6 %) and Verbenaceae (5 %). Regression equation analyses showed that the literature grew by approximately 20 % per year (period: 2005-2015). Lastly, in the final section, insights for future research are discussed. We focused on some caveats for future data collection and analysis. Current critical points mainly deal with (a) not uniform methods used, which prevent proper comparison of the results; (b) inaccurate tested concentrations, frequently 100 % concentration corresponded to the gross extract, where the exact amounts of extracted substances are unknown; and (c) not homogeneous size of tested tick instars and species. Overall, the knowledge summarized in this review may be helpful for comparative screening among extensive numbers of plant-borne preparations, in order to develop newer and safer tick control tools.
- MeSH
- akaricidy farmakologie MeSH
- Asteraceae chemie MeSH
- dobytek MeSH
- Fabaceae chemie MeSH
- hluchavkovité chemie MeSH
- infekce přenášené vektorem MeSH
- klíště účinky léků MeSH
- kontrola klíšťat metody MeSH
- nemoci přenášené klíšťaty prevence a kontrola MeSH
- Rhipicephalus sanguineus účinky léků MeSH
- rostlinné extrakty farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Tick-borne encephalitis (TBE) is an important and severe neurological illness occurring in large areas of Europe and northern Asia. Only a small proportion of those infected develop clinical symptoms. The symptomatic cases are, however, characterized with fevers and debilitating encephalitis that might progress into chronic disease or fatal infections. This review summarizes data on clinical presentation, pathogenesis and pathology of TBE in humans, and of experimental TBE in animal models with the purpose to explain why is TBE such a severe disease clinically.
- MeSH
- dítě MeSH
- dospělí MeSH
- klíště virologie MeSH
- klíšťová encefalitida patologie prevence a kontrola MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- virové vakcíny aplikace a dávkování MeSH
- viry klíšťové encefalitidy MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Tick-borne encephalitis (TBE), a disease caused by tick-borne encephalitis virus (TBEV), represents a serious neural infection of humans in Europe and Asia. The main reservoir hosts of TBEV are ticks, rodents and insectivores, but domestic animals may also be infected with the virus. This review summarizes what is known about TBE in domestic species (e.g., dogs, horses), in which infection may manifest with clinical signs similar to those seen in severe human cases. We also focus on TBE in ruminants where TBE infections are typically asymptomatic and do not cause health problems in the infected hosts. However, the risk to human health is the main problem of asymptomatic infection, because the presence of TBEV in the milk of infected ruminants can serve as a source of TBE infection via the alimentary route. An experimental veterinary vaccine was developed recently, and future vaccination of selected domestic animals is proposed to avoid the development of severe TBE symptoms in sensitive animals (e.g., dogs, horses) or to decrease the risk of alimentary infection in humans (e.g., goats and sheep).
- MeSH
- exotická zvířata virologie MeSH
- hospodářská zvířata * virologie MeSH
- klíšťová encefalitida přenos veterinární virologie MeSH
- koně virologie MeSH
- kontaminace potravin MeSH
- lidé MeSH
- mléčné výrobky virologie MeSH
- nemoci koní virologie MeSH
- nemoci přenášené potravou virologie MeSH
- nemoci psů virologie MeSH
- přežvýkavci virologie MeSH
- psi virologie MeSH
- vakcinace veterinární MeSH
- virové zoonózy přenos MeSH
- viry klíšťové encefalitidy * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi virologie MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
