Tick-borne encephalitis (TBE) virus (TBEV) is transmitted to humans via tick bites. Infection is benign in >90% of the cases but can cause mild (<5%), moderate (<4%), or severe (<1%) encephalitis. We show here that ∼10% of patients hospitalized for severe TBE in cohorts from Austria, Czech Republic, and France carry auto-Abs neutralizing IFN-α2, -β, and/or -ω at the onset of disease, contrasting with only ∼1% of patients with moderate and mild TBE. These auto-Abs were found in two of eight patients who died and none of 13 with silent infection. The odds ratios (OR) for severe TBE in individuals with these auto-Abs relative to those without them in the general population were 4.9 (95% CI: 1.5-15.9, P < 0.0001) for the neutralization of only 100 pg/ml IFN-α2 and/or -ω, and 20.8 (95% CI: 4.5-97.4, P < 0.0001) for the neutralization of 10 ng/ml IFN-α2 and -ω. Auto-Abs neutralizing type I IFNs accounted for ∼10% of severe TBE cases in these three European cohorts.

• MeSH
• autoprotilátky * imunologie   MeSH
• dospělí MeSH
• interferon typ I * imunologie   MeSH
• klíšťová encefalitida * imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• neutralizující protilátky * imunologie   MeSH
• senioři MeSH
• viry klíšťové encefalitidy imunologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Rakousko MeSH

The presented project is focused on the development of novel antiviral agents against tick-borne encephalitis (TBE) virus and other flaviviruses. Our major biological target is the NS5 protein, a key enzyme that consists of an RNA dependent RNA polymerase (RdRp) responsible for replication of the flavivirus genome and a methyltransferase (MTase) essential for methylation of the newly synthesized RNA. The goal of this project is to design, synthesize and biologically evaluate novel inhibitors of both of these essential NS5 protein domains. The rational design of the methyltransferase inhibitors will be based on our extensive crystallographic studies and the first generation of compounds that we have already prepared. Congruently, the nucleoside and nucleotide inhibitors of the RdRp subunit will be based on our previously gained expertise. All the prepared small-molecule inhibitors of NS5 protein will be evaluated on the enzyme level as well as in infected cell cultures. The lead compounds will be tested in our mice model of TBE to select the best candidate for clinical trials.

Tento projekt je zaměřen na vývoj nových antivirotik proti viru klíšťové encefalitidy (TBE) a další flaviviry. Náš hlavní biologicky cíl je NS5 protein, který je klíčovým enzymem, který obsahuje RNA dependentní RNA polymerasu (RdRp) zodpovědnou za replikaci flavivirového genomu a methyltransferasu (MTasa) nezbytnou pro metylaci nově syntetizované RNA. Cílem toho projektu je design, syntéza a studium biologické aktivity nových inhibitorů obout těchto domén NS5 proteinu. Racionální design nových inhibitorů methyltransferasy bude založen na podrobných krystalografických studiích a první generaci sloučenin, které jsme v naší laboratoři již připravili. Zároveň, nukleosidové a nukleotidové inhibitory RdRp podjednoty budou založeny na našich předchozích pozorováních. Všechny připravené inhibitory NS5 proteinu budou testovány jak na úrovni enzymu, tak v infikovaných buněčných kulturách. Vybrané sloučeniny budou testovány na myším modelu TBE. Na základě těchto studii bude zvolen vhodný kandidát pro klinické testy.

• Klíčová slova
• inhibitory, inhibitors, tick-borne encephalitis, antivirotika, antivirotics, klíšťová encefalitida,, RNA dependentní RNA polymerasa, MTasa, RNA dependent RNA polymerase, MTase,

• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

In this study, we employed short- and long-read sequencing technologies to delineate the transcriptional architecture of the human monkeypox virus and to identify key regulatory elements that govern its gene expression. Specifically, we conducted a transcriptomic analysis to annotate the transcription start sites (TSSs) and transcription end sites (TESs) of the virus by utilizing Cap Analysis of gene expression sequencing on the Illumina platform and direct RNA sequencing on the Oxford Nanopore technology device. Our investigations uncovered significant complexity in the use of alternative TSSs and TESs in viral genes. In this research, we also detected the promoter elements and poly(A) signals associated with the viral genes. Additionally, we identified novel genes in both the left and right variable regions of the viral genome.IMPORTANCEGenerally, gaining insight into how the transcription of a virus is regulated offers insights into the key mechanisms that control its life cycle. The recent outbreak of the human monkeypox virus has underscored the necessity of understanding the basic biology of its causative agent. Our results are pivotal for constructing a comprehensive transcriptomic atlas of the human monkeypox virus, providing valuable resources for future studies.

• MeSH
• genom virový MeSH
• lidé MeSH
• počátek transkripce * MeSH
• promotorové oblasti (genetika) MeSH
• RNA virová genetika   MeSH
• sekvenční analýza RNA * metody   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom * MeSH
• virus opičích neštovic genetika   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Tick-borne encephalitis virus (TBEV) targets the central nervous system (CNS), leading to potentially severe neurological complications. The neurovascular unit plays a fundamental role in the CNS and in the neuroinvasion of TBEV. However, the role of human brain pericytes, a key component of the neurovascular unit, during TBEV infection has not yet been elucidated. In this study, TBEV infection of the primary human brain perivascular pericytes was investigated with highly virulent Hypr strain and mildly virulent Neudoerfl strain. We used Luminex assay to measure cytokines/chemokines and growth factors. Both viral strains showed comparable replication kinetics, peaking at 3 days post infection (dpi). Intracellular viral RNA copies peaked at 6 dpi for Hypr and 3 dpi for Neudoerfl cultures. According to immunofluorescence staining, only small proportion of pericytes were infected (3% for Hypr and 2% for Neudoerfl), and no cytopathic effect was observed in the infected cells. In cell culture supernatants, IL-6 production was detected at 3 dpi, together with slight increases in IL-15 and IL-4, but IP-10, RANTES and MCP-1 were the main chemokines released after TBEV infection. These chemokines play key roles in both immune defense and immunopathology during TBE. This study suggests that pericytes are an important source of these signaling molecules during TBEV infection in the brain.

• MeSH
• chemokin CCL5 * metabolismus   MeSH
• chemokin CXCL10 * metabolismus   MeSH
• cytokiny metabolismus   MeSH
• klíšťová encefalitida * virologie   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mozek * virologie   metabolismus   patologie   MeSH
• pericyty * virologie   metabolismus   MeSH
• replikace viru MeSH
• viry klíšťové encefalitidy * fyziologie   patogenita   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Tick-borne encephalitis virus (TBEV) is a neurotropic orthoflavivirus responsible for severe infections of the central nervous system. Although neurons are predominantly targeted, specific involvement of microglia in pathogenesis of TBE is not yet fully understood. In this study, the susceptibility of human microglia to TBEV is investigated, focusing on productive infection and different immune responses of different viral strains. We investigated primary human microglia and two immortalized microglial cell lines exposed to three TBEV strains (Hypr, Neudörfl and 280), each differing in virulence. Our results show that all microglia cultures tested support long-term productive infections, regardless of the viral strain. In particular, immune response varied significantly with the viral strain, as shown by the differential secretion of cytokines and chemokines such as IP-10, MCP-1, IL-8 and IL-6, quantified using a Luminex 48-plex assay. The most virulent strain triggered the highest cytokine induction. Electron tomography revealed substantial ultrastructural changes in the infected microglia, despite the absence of cytopathic effects. These findings underscore the susceptibility of human microglia to TBEV and reveal strain-dependent variations in viral replication and immune responses, highlighting the complex role of microglia in TBEV-induced neuropathology and contribute to a deeper understanding of TBE pathogenesis and neuroinflammation.

• MeSH
• buněčné linie MeSH
• cytokiny * metabolismus   MeSH
• klíšťová encefalitida * virologie   patologie   imunologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• mikroglie * virologie   imunologie   patologie   MeSH
• neurozánětlivé nemoci virologie   patologie   imunologie   MeSH
• replikace viru MeSH
• viry klíšťové encefalitidy * patogenita   fyziologie   imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Tick-borne encephalitis virus (TBEV) is a tick-borne flavivirus that induces severe central nervous system disorders. It has recently raised concerns due to an expanding geographical range and increasing infection rates. Existing vaccines, though effective, face low coverage rates in numerous TBEV endemic regions. Our previous work demonstrated the immunogenicity and full protection afforded by a TBEV vaccine based on virus-like particles (VLPs) produced in Leishmania tarentolae cells in immunization studies in a mouse model. In the present study, we explored the impact of adjuvants (AddaS03TM, Alhydrogel®+MPLA) and administration routes (subcutaneous, intramuscular) on the immune response. Adjuvanted groups exhibited significantly enhanced antibody responses, higher avidity, and more balanced Th1/Th2 response. IFN-γ responses depended on the adjuvant type, while antibody levels were influenced by both adjuvant and administration routes. The combination of Leishmania-derived TBEV VLPs with Alhydrogel® and MPLA via intramuscular administration emerged as a highly promising prophylactic vaccine candidate, eliciting a robust, balanced immune response with substantial neutralization potential.

• MeSH
• adjuvancia imunologická * aplikace a dávkování   MeSH
• adjuvantní vakcína aplikace a dávkování   MeSH
• imunogenicita vakcíny MeSH
• injekce intramuskulární MeSH
• interferon gama imunologie   MeSH
• klíšťová encefalitida * prevence a kontrola   imunologie   MeSH
• Leishmania * imunologie   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• neutralizující protilátky krev   imunologie   MeSH
• protilátky virové * krev   imunologie   MeSH
• syntetické vakcíny * imunologie   aplikace a dávkování   MeSH
• Th1 buňky imunologie   MeSH
• virové vakcíny * imunologie   aplikace a dávkování   MeSH
• viry klíšťové encefalitidy * imunologie   MeSH
• VLP vakcíny * imunologie   aplikace a dávkování   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV) are spread by mosquitoes and cause human disease and mortality in tropical areas. In contrast, Powassan virus (POWV), which causes severe neurologic illness, is a flavivirus transmitted by ticks in temperate regions of the Northern hemisphere. We find serologic neutralizing activity against POWV in individuals living in Mexico and Brazil. Monoclonal antibodies P002 and P003, which were derived from a resident of Mexico (where POWV is not reported), neutralize POWV lineage I by recognizing an epitope on the virus envelope domain III (EDIII) that is shared with a broad range of tick- and mosquito-borne flaviviruses. Our findings raise the possibility that POWV, or a flavivirus closely related to it, infects humans in the tropics.

• MeSH
• epitopy imunologie   MeSH
• Flavivirus imunologie   MeSH
• klíšťata virologie   imunologie   MeSH
• lidé MeSH
• monoklonální protilátky imunologie   MeSH
• neutralizující protilátky * imunologie   MeSH
• protilátky virové imunologie   MeSH
• viry klíšťové encefalitidy imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Brazílie MeSH
• Mexiko MeSH

• MeSH
• biologické markery MeSH
• humanizované monoklonální protilátky terapeutické užití   MeSH
• intermediární filamenta MeSH
• klíšťová encefalitida * genetika   prevence a kontrola   terapie   MeSH
• lidé MeSH
• Parkinsonova nemoc postencefalitická MeSH
• polymorfismus genetický MeSH
• rizikové faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• novinové články MeSH
• rozhovory MeSH

The emergence of tick-borne encephalitis (TBE) in Europe marked several significant milestones. The discovery of TBE in Czechoslovakia in 1948, with Gallia and Krejčí simultaneously isolating the TBE virus (TBEV) from human samples for the first time in Europe outside the Soviet Union, was pivotal. Subsequent TBEV isolation from ticks suggested the viral transmission via this vector. In 1951, the outbreak in Rožňava in Slovakia (Czechoslovakia) revealed an unexpected mode of transmission, unpasteurized milk from a local dairy, challenging existing understanding. Investigations exposed illicit practices of mixing cow's milk with goat's milk for economic gains. Laboratory research confirmed the outbreak was caused by TBEV, which was substantiated by serological analyses. This was the first and largest documented alimentary TBE outbreak in history. In this review, we delve into both published sources and unpublished archival data, offering a comprehensive understanding of these historic accomplishments and shedding light on these pivotal moments.

• MeSH
• epidemický výskyt choroby MeSH
• klíšťová encefalitida * MeSH
• lidé MeSH
• skot MeSH
• viry klíšťové encefalitidy * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Geografické názvy
• Evropa MeSH
• SSSR MeSH

The life cycle of enveloped viruses is closely linked to host-cell lipids. However, changes in lipid metabolism during infections with the tick-borne encephalitis virus (TBEV) have not been described. TBEV is a medically important orthoflavivirus, which is endemic to many parts of Europe and Asia. In the present study, we performed targeted lipidomics with HPLC-MS/MS to evaluate changes in phospholipid and sphingolipid concentrations in TBEV-infected human neuronal SK-N-SH cells. TBEV infections significantly increased phosphatidylcholine, phosphatidylinositol, and phosphatidylserine levels within 48 h post-infection (hpi). Sphingolipids were slightly increased in dihydroceramides within 24 hpi. Later, at 48 hpi, the contents of sphinganine, dihydroceramides, ceramides, glucosylceramides, and ganglioside GD3 were elevated. On the other hand, sphingosine-1-phosphate content was slightly reduced in TBEV-infected cells. Changes in sphingolipid concentrations were accompanied by suppressed expression of a majority of the genes linked to sphingolipid and glycosphingolipid metabolism. Furthermore, we found that a pharmacological inhibitor of sphingolipid synthesis, fenretinide (4-HPR), inhibited TBEV infections in SK-N-SH cells. Taken together, our results suggested that both structural and signaling functions of lipids could be affected during TBEV infections. These changes might be connected to virus propagation and/or host-cell defense.

• MeSH
• buněčné linie MeSH
• fosfolipidy * metabolismus   MeSH
• interakce hostitele a patogenu MeSH
• lidé MeSH
• lipidomika MeSH
• metabolismus lipidů MeSH
• neurony * virologie   metabolismus   MeSH
• sfingolipidy * metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• viry klíšťové encefalitidy * fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH