• MeSH
• Babesia * genetika   MeSH
• babezióza * MeSH
• lidé MeSH
• protozoální DNA MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protozoální DNA MeSH

Babesia divergens is an emerging tick-borne pathogen considered as the principal causative agent of bovine babesiosis in Europe with a notable zoonotic risk to human health. Despite its increasing impact, considerable gaps persist in our understanding of the molecular interactions between this parasite and its hosts. In this study, we address the current limitation of functional genomic tools in B. divergens and introduce a stable transfection system specific to this parasite. We define the parameters for a drug selection system hdhfr-WR99210 and evaluate different transfection protocols for highly efficient generation of transgenic parasites expressing GFP. We proved that plasmid delivery into bovine erythrocytes prior to their infection is the most optimal transfection approach for B. divergens, providing novel evidence of Babesia parasites' ability to spontaneously uptake external DNA from erythrocytes cytoplasm. Furthermore, we validated the bidirectional and symmetrical activity of ef-tgtp promoter, enabling simultaneous expression of external genes. Lastly, we generated a B. divergens knockout line by targeting a 6-cys-e gene locus. The observed dispensability of this gene in intraerythrocytic parasite development makes it a suitable recipient locus for further transgenic application. The platform for genetic manipulations presented herein serves as the initial step towards developing advanced functional genomic tools enabling the discovery of B. divergens molecules involved in host-vector-pathogen interactions.

• Klíčová slova
• 6-cys-e gene knockout, Babesia divergens, GFP-expression, bidirectional promoter, erythrocytes pre-loading, gene targeting, transfection system,
• MeSH
• Babesia * genetika   MeSH
• babezióza * parazitologie   MeSH
• erytrocyty parazitologie   MeSH
• genový targeting MeSH
• lidé MeSH
• transfekce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Propagation of Plasmodium spp. and Babesia/Theileria spp. vertebrate blood stages relies on the mediated acquisition of nutrients available within the host's red blood cell (RBC). The cellular processes of uptake, trafficking and metabolic processing of host RBC proteins are thus crucial for the intraerythrocytic development of these parasites. In contrast to malarial Plasmodia, the molecular mechanisms of uptake and processing of the major RBC cytoplasmic protein hemoglobin remain widely unexplored in intraerythrocytic Babesia/Theileria species. In the paper, we thus provide an updated comparison of the intraerythrocytic stage feeding mechanisms of these two distantly related groups of parasitic Apicomplexa. As the associated metabolic pathways including proteolytic degradation and networks facilitating heme homeostasis represent attractive targets for diverse antimalarials, and alterations in these pathways underpin several mechanisms of malaria drug resistance, our ambition is to highlight some fundamental differences resulting in different implications for parasite management with the potential for novel interventions against Babesia/Theileria infections.

• Klíčová slova
• Babesia, Plasmodium, Theileria, babesiosis, hemoglobin, malaria, piroplasmida, piroplasmosis,
• Publikační typ
• časopisecké články MeSH

Apicomplexan genomes encode multiple pepsin-family aspartyl proteases (APs) that phylogenetically cluster to six independent clades (A to F). Such diversification has been powered by the function-driven evolution of the ancestral apicomplexan AP gene and is associated with the adaptation of various apicomplexan species to different strategies of host infection and transmission through various invertebrate vectors. To estimate the potential roles of Babesia APs, we performed qRT-PCR-based expressional profiling of Babesia microti APs (BmASP2, 3, 5, 6), which revealed the dynamically changing mRNA levels and indicated the specific roles of individual BmASP isoenzymes throughout the life cycle of this parasite. To expand on the current knowledge on piroplasmid APs, we searched the EuPathDB and NCBI GenBank databases to identify and phylogenetically analyse the complete sets of APs encoded by the genomes of selected Babesia and Theileria species. Our results clearly determine the potential roles of identified APs by their phylogenetic relation to their homologues of known function-Plasmodium falciparum plasmepsins (PfPM I-X) and Toxoplasma gondii aspartyl proteases (TgASP1-7). Due to the analogies with plasmodial plasmepsins, piroplasmid APs represent valuable enzymatic targets that are druggable by small molecule inhibitors-candidate molecules for the yet-missing specific therapy for babesiosis.

• Klíčová slova
• Babesia, apicomplexa, aspartyl protease, piroplasmida, plasmepsin,
• Publikační typ
• časopisecké články MeSH

Hematophagous arthropods are responsible for the transmission of a variety of pathogens that cause disease in humans and animals. Ticks of the Ixodes ricinus complex are vectors for some of the most frequently occurring human tick-borne diseases, particularly Lyme borreliosis and tick-borne encephalitis virus (TBEV). The search for vaccines against these diseases is ongoing. Efforts during the last few decades have primarily focused on understanding the biology of the transmitted viruses, bacteria and protozoans, with the goal of identifying targets for intervention. Successful vaccines have been developed against TBEV and Lyme borreliosis, although the latter is no longer available for humans. More recently, the focus of intervention has shifted back to where it was initially being studied which is the vector. State of the art technologies are being used for the identification of potential vaccine candidates for anti-tick vaccines that could be used either in humans or animals. The study of the interrelationship between ticks and the pathogens they transmit, including mechanisms of acquisition, persistence and transmission have come to the fore, as this knowledge may lead to the identification of critical elements of the pathogens' life-cycle that could be targeted by vaccines. Here, we review the status of our current knowledge on the triangular relationships between ticks, the pathogens they carry and the mammalian hosts, as well as methods that are being used to identify anti-tick vaccine candidates that can prevent the transmission of tick-borne pathogens.

• Klíčová slova
• Anaplasma, Babesia, Borrelia, Ixodes, Midgut, Rickettsia, Saliva, TBEV, Tick, Vaccine,
• MeSH
• Borrelia MeSH
• infekce přenášené vektorem MeSH
• klíště mikrobiologie   virologie   MeSH
• klíšťová encefalitida prevence a kontrola   MeSH
• kousnutí klíštětem prevence a kontrola   MeSH
• lidé MeSH
• lymeská nemoc prevence a kontrola   MeSH
• nemoci přenášené klíšťaty prevence a kontrola   přenos   MeSH
• proteiny členovců imunologie   MeSH
• sliny MeSH
• vakcíny imunologie   MeSH
• viry klíšťové encefalitidy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• proteiny členovců MeSH
• vakcíny MeSH

Although Babesia represents an important worldwide veterinary threat and an emerging risk to humans, this parasite has been poorly studied as compared to Plasmodium, its malaria-causing relative. In fact, Babesia employs highly specific survival strategies during its intraerythrocytic development and its intricate journey through the tick vector. This review introduces a substantially extended molecular phylogeny of the order Piroplasmida, challenging previous taxonomic classifications. The intriguing developmental proficiencies of Babesia are highlighted and compared with those of other haemoparasitic Apicomplexa. Molecular mechanisms associated with distinctive events in the Babesia life cycle are emphasized as potential targets for the development of Babesia-specific treatments.

• Klíčová slova
• Babesia, hard ticks, life cycle, molecular phylogeny, transmission,
• MeSH
• Babesia klasifikace   genetika   růst a vývoj   MeSH
• babezióza parazitologie   MeSH
• fylogeneze * MeSH
• lidé MeSH
• Piroplasmida klasifikace   genetika   růst a vývoj   MeSH
• protozoální geny genetika   MeSH
• stadia vývoje genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Babesiosis is a tick-transmitted zoonosis caused by apicomplexan parasites of the genus Babesia. Treatment of this emerging malaria-related disease has relied on antimalarial drugs and antibiotics. The proteasome of Plasmodium, the causative agent of malaria, has recently been validated as a target for anti-malarial drug development and therefore, in this study, we investigated the effect of epoxyketone (carfilzomib, ONX-0914 and epoxomicin) and boronic acid (bortezomib and ixazomib) proteasome inhibitors on the growth and survival of Babesia. Testing the compounds against Babesia divergens ex vivo revealed suppressive effects on parasite growth with activity that was higher than the cytotoxic effects on a non-transformed mouse macrophage cell line. Furthermore, we showed that the most-effective compound, carfilzomib, significantly reduces parasite multiplication in a Babesia microti infected mouse model without noticeable adverse effects. In addition, treatment with carfilzomib lead to an ex vivo and in vivo decrease in proteasome activity and accumulation of polyubiquitinated proteins compared to untreated control. Overall, our results demonstrate that the Babesia proteasome is a valid target for drug development and warrants the design of potent and selective B. divergens proteasome inhibitors for the treatment of babesiosis.

• Klíčová slova
• Babesia, Carfilzomib, Cytotoxicity, Epoxyketone, Proteasome,
• MeSH
• Babesia microti účinky léků   genetika   růst a vývoj   MeSH
• Babesia účinky léků   genetika   růst a vývoj   MeSH
• babezióza farmakoterapie   MeSH
• buněčné linie MeSH
• inhibitory proteasomu aplikace a dávkování   škodlivé účinky   farmakologie   terapeutické užití   MeSH
• kyseliny boronové farmakologie   MeSH
• makrofágy účinky léků   parazitologie   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• oligopeptidy farmakologie   MeSH
• proteasomový endopeptidasový komplex účinky léků   MeSH
• proteom účinky léků   genetika   MeSH
• systémy cílené aplikace léků * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• validační studie MeSH
• Názvy látek
• carfilzomib MeSH Prohlížeč
• epoxomicin MeSH Prohlížeč
• inhibitory proteasomu MeSH
• kyseliny boronové MeSH
• oligopeptidy MeSH
• proteasomový endopeptidasový komplex MeSH
• proteom MeSH

Although apicomplexan parasites of the group Piroplasmida represent commonly identified global risks to both animals and humans, detailed knowledge of their life cycles is surprisingly limited. Such a discrepancy results from incomplete literature reports, nomenclature disunity and recently, from large numbers of newly described species. This review intends to collate and summarize current knowledge with respect to piroplasm phylogeny. Moreover, it provides a comprehensive view of developmental events of Babesia, Theileria, and Cytauxzoon representative species, focusing on uniform consensus of three consecutive phases: (i) schizogony and merogony, asexual multiplication in blood cells of the vertebrate host; (ii) gamogony, sexual reproduction inside the tick midgut, later followed by invasion of kinetes into the tick internal tissues; and (iii) sporogony, asexual proliferation in tick salivary glands resulting in the formation of sporozoites. However, many fundamental differences in this general consensus occur and this review identifies variables that should be analyzed prior to further development of specific anti-piroplasm strategies, including the attractive targeting of life cycle stages of Babesia or Theileria tick vectors.

• Klíčová slova
• Babesia, Theileria, developmental cycle, gamogony, merogony, piroplasms, sporogony,
• MeSH
• fylogeneze MeSH
• Piroplasmida klasifikace   genetika   růst a vývoj   MeSH
• stadia vývoje * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Ticks possess components of a primordial complement system that presumably play a role in the interaction of the tick immune system with tick-borne pathogens and affect their transmission. Here we characterized a novel complement component, tagged as IrC2/Bf, from the hard tick Ixodes ricinus, the principal vector of Lyme disease in Europe. IrC2/Bf is a multi-domain molecule composed of 5-7 CCP modules, varied by alternative splicing, followed by a von Willebrand factor A domain and a C-terminal trypsin-like domain. The primary structure and molecular architecture of IrC2/Bf displays the closest homology to the C3-complement component convertases described in horseshoe crabs. The irc2/bf gene is mainly expressed in the tick fat body associated with the trachea and, as determined by western blotting, the protein is present in low amounts in tick hemolymph. Expression of irc2/bf mRNA was significantly up-regulated in response to the intra-hemocoelic injection of the yeast Candida albicans and all tested Borrelia sp. strains (B. burgdorferi NE5264, B. burgdorferi CB26, B. garinii MSLB, B. afzelii CB43), but was not affected by injection of model Gram-negative and Gram-positive bacteria or the aseptic injection control. In-line with these results, RNAi-mediated silencing of irc2/bf inhibited phagocytosis of B. afzelii and C. albicans but not the other bacteria. Tissue expression profiles, specific responses to microbial challenges, and patterns of phagocytic phenotypes upon RNAi silencing observed for IrC2/Bf match well with the previously reported characteristics of I. ricinus C3-related molecule 1 (IrC3-1). Therefore we presume that IrC2/Bf functions as a convertase in the same complement activation pathway protecting ticks against yeast and Borrelia infection.

• Klíčová slova
• Borrelia, C3-complement convertase, Factor B, Ixodes, Phagocytosis, Tick immunity,
• MeSH
• aktivace komplementu MeSH
• Borrelia burgdorferi imunologie   MeSH
• Candida albicans imunologie   MeSH
• fagocytóza MeSH
• hemocyty imunologie   mikrobiologie   MeSH
• hmyzí proteiny genetika   metabolismus   MeSH
• infekce přenášené vektorem MeSH
• interakce hostitele a patogenu MeSH
• kandidóza imunologie   MeSH
• klíště imunologie   MeSH
• komplement C3 genetika   metabolismus   MeSH
• lidé MeSH
• lymeská nemoc imunologie   MeSH
• malá interferující RNA genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hmyzí proteiny MeSH
• komplement C3 MeSH
• malá interferující RNA MeSH

Helminths and bacteria are major players in the mammalian gut ecosystem and each influences the host immune system and health. Declines in helminth prevalence and bacterial diversity appear to play a role in the dramatic rise of immune mediated inflammatory diseases (IMIDs) in western populations. Helminths are potent modulators of immune system and their reintroduction is a promising therapeutic avenue for IMIDs. However, the introduction of helminths represents a disturbance for the host and it is important to understand the impact of helminth reintroduction on the host, including the immune system and gut microbiome. We tested the impact of a benign tapeworm, Hymenolepis diminuta, in a rat model system. We find that H. diminuta infection results in increased interleukin 10 gene expression in the beginning of the prepatent period, consistent with induction of a type 2 immune response. We also find induction of humoral immunity during the patent period, shown here by increased IgA in feces. Further, we see an immuno-modulatory effect in the small intestine and spleen in patent period, as measured by reductions in tissue immune cells. We observed shifts in microbiota community composition during the patent period (beta-diversity) in response to H. diminuta infection. However, these compositional changes appear to be minor; they occur within families and genera common to both treatment groups. There was no change in alpha diversity. Hymenolepis diminuta is a promising model for helminth therapy because it establishes long-term, stable colonization in rats and modulates the immune system without causing bacterial dysbiosis. These results suggest that the goal of engineering a therapeutic helminth that can safely manipulate the mammalian immune system without disrupting the rest of the gut ecosystem is in reach.

• MeSH
• Bacteria klasifikace   izolace a purifikace   MeSH
• biodiverzita MeSH
• biologické modely * MeSH
• feces chemie   MeSH
• fylogeneze MeSH
• Hymenolepis diminuta imunologie   MeSH
• imunitní systém * MeSH
• imunoglobulin A analýza   imunologie   MeSH
• interakce hostitele a parazita imunologie   MeSH
• interleukin-10 genetika   metabolismus   MeSH
• krysa rodu Rattus MeSH
• potkani Wistar MeSH
• regulace genové exprese imunologie   MeSH
• slezina imunologie   MeSH
• střeva mikrobiologie   parazitologie   MeSH
• střevní mikroflóra * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• imunoglobulin A MeSH
• interleukin-10 MeSH