Narcolepsy type 1 (NT1) is caused by a loss of hypocretin/orexin transmission. Risk factors include pandemic 2009 H1N1 influenza A infection and immunization with Pandemrix®. Here, we dissect disease mechanisms and interactions with environmental triggers in a multi-ethnic sample of 6,073 cases and 84,856 controls. We fine-mapped GWAS signals within HLA (DQ0602, DQB1*03:01 and DPB1*04:02) and discovered seven novel associations (CD207, NAB1, IKZF4-ERBB3, CTSC, DENND1B, SIRPG, PRF1). Significant signals at TRA and DQB1*06:02 loci were found in 245 vaccination-related cases, who also shared polygenic risk. T cell receptor associations in NT1 modulated TRAJ*24, TRAJ*28 and TRBV*4-2 chain-usage. Partitioned heritability and immune cell enrichment analyses found genetic signals to be driven by dendritic and helper T cells. Lastly comorbidity analysis using data from FinnGen, suggests shared effects between NT1 and other autoimmune diseases. NT1 genetic variants shape autoimmunity and response to environmental triggers, including influenza A infection and immunization with Pandemrix®.

• MeSH
• autoimunita genetika   MeSH
• autoimunitní nemoci * epidemiologie   genetika   MeSH
• chřipka lidská * epidemiologie   genetika   MeSH
• lidé MeSH
• narkolepsie * chemicky indukované   genetika   MeSH
• vakcíny proti chřipce * škodlivé účinky   MeSH
• virus chřipky A, podtyp H1N1 * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• vakcíny proti chřipce * MeSH

BACKGROUND: Influenza viruses are dangerous pathogens. Seventy-Seven genomes of recently emerged genotype 4 reassortant Eurasian avian-like H1N1 virus (G4-EA-H1N1) are currently available. We investigated the presence and variation of potential G-quadruplex forming sequences (PQS), which can serve as targets for antiviral treatment. RESULTS: PQS were identified in all 77 genomes. The total number of PQS in G4-EA-H1N1 genomes was 571. Interestingly, the number of PQS per genome in individual close relative viruses varied from 4 to 12. PQS were not randomly distributed in the 8 segments of the G4-EA-H1N1 genome, the highest frequency of PQS being found in the NP segment (1.39 per 1000 nt), which is considered a potential target for antiviral therapy. In contrast, no PQS was found in the NS segment. Analyses of variability pointed the importance of some PQS; even if genome variation of influenza virus is extreme, the PQS with the highest G4Hunter score is the most conserved in all tested genomes. G-quadruplex formation in vitro was experimentally confirmed using spectroscopic methods. CONCLUSIONS: The results presented here hint several G-quadruplex-forming sequences in G4-EA-H1N1 genomes, that could provide good therapeutic targets.

• Klíčová slova
• G-quadruplex, G4Hunter, Influenza virus,
• MeSH
• chřipka lidská * MeSH
• G-kvadruplexy * MeSH
• genom virový MeSH
• genotyp MeSH
• lidé MeSH
• reassortantní viry genetika   MeSH
• virus chřipky A, podtyp H1N1 * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The mutual dependence of human and animal health is central to the One Health initiative as an integrated strategy for infectious disease control and management. A crucial element of the One Health includes preparation and response to influenza A virus (IAV) threats at the human-animal interface. The IAVs are characterized by extensive genetic variability, they circulate among different hosts and can establish host-specific lineages. The four main hosts are: avian, swine, human and equine, with occasional transmission to other mammalian species. The host diversity is mirrored in the range of the RT-qPCR assays for IAV detection. Different assays are recommended by the responsible health authorities for generic IAV detection in birds, swine or humans. In order to unify IAV monitoring in different hosts and apply the One Health approach, we developed a single RT-qPCR assay for universal detection of all IAVs of all subtypes, species origin and global distribution. The assay design was centred on a highly conserved region of the IAV matrix protein (MP)-segment identified by a comprehensive analysis of 99,353 sequences. The reaction parameters were effectively optimised with efficiency of 93-97% and LOD95% of approximately ten IAV templates per reaction. The assay showed high repeatability, reproducibility and robustness. The extensive in silico evaluation demonstrated high inclusivity, i.e. perfect sequence match in the primers and probe binding regions, established as 94.6% for swine, 98.2% for avian and 100% for human H3N2, pandemic H1N1, as well as other IAV strains, resulting in an overall predicted detection rate of 99% on the analysed dataset. The theoretical predictions were confirmed and extensively validated by collaboration between six veterinary or human diagnostic laboratories on a total of 1970 specimens, of which 1455 were clinical and included a diverse panel of IAV strains.

• MeSH
• chřipka lidská diagnóza   virologie   MeSH
• infekce viry z čeledi Orthomyxoviridae diagnóza   virologie   MeSH
• lidé MeSH
• nemoci prasat diagnóza   virologie   MeSH
• One Health MeSH
• polymerázová řetězová reakce s reverzní transkripcí metody   MeSH
• prasata MeSH
• ptačí chřipka u ptáků diagnóza   virologie   MeSH
• ptáci virologie   MeSH
• reprodukovatelnost výsledků MeSH
• virus chřipky A, podtyp H1N1 genetika   izolace a purifikace   MeSH
• virus chřipky A, podtyp H3N2 genetika   izolace a purifikace   MeSH
• virus chřipky A genetika   izolace a purifikace   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH

BACKGROUND: The 2018/2019 influenza season in the WHO European Region was dominated by influenza A (H1N1)pdm09 and (H3N2) viruses, with very few influenza B viruses detected. METHODS: Countries in the European Region reported virus characterization data to The European Surveillance System for weeks 40/2018 to 20/2019. These virus antigenic and genetic characterization and haemagglutinin (HA) sequence data were analysed to describe and assess circulating viruses relative to the 2018/2019 vaccine virus components for the northern hemisphere. RESULTS: Thirty countries reported 4776 viruses characterized genetically and 3311 viruses antigenically. All genetically characterized A(H1N1)pdm09 viruses fell in subclade 6B.1A, of which 90% carried the amino acid substitution S183P in the HA gene. Antigenic data indicated that circulating A(H1N1)pdm09 viruses were similar to the 2018/2019 vaccine virus. Genetic data showed that A(H3N2) viruses mostly fell in clade 3C.2a (75%) and 90% of which were subclade 3C.2a1b. A lower proportion fell in clade 3C.3a (23%) and were antigenically distinct from the vaccine virus. All B/Victoria viruses belonged to clade 1A; 30% carried a double amino acid deletion in HA and were genetically and antigenically similar to the vaccine virus component, while 55% carried a triple amino acid deletion or no deletion in HA; these were antigenically distinct from each other and from the vaccine component. All B/Yamagata viruses belonged to clade 3 and were antigenically similar to the virus component in the quadrivalent vaccine for 2018/2019. CONCLUSIONS: A simultaneous circulation of genetically and antigenically diverse A(H3N2) and B/Victoria viruses was observed and represented a challenge to vaccine strain selection.

• Klíčová slova
• Antigenic, Europe, Genetic, Influenza, Surveillance, Vaccine,
• MeSH
• Alphainfluenzavirus * MeSH
• chřipka lidská * epidemiologie   prevence a kontrola   MeSH
• fylogeneze MeSH
• hemaglutininové glykoproteiny viru chřipky genetika   MeSH
• lidé MeSH
• RNA virová MeSH
• Světová zdravotnická organizace MeSH
• vakcíny proti chřipce * MeSH
• virus chřipky A, podtyp H1N1 * genetika   MeSH
• virus chřipky A, podtyp H3N2 genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hemaglutininové glykoproteiny viru chřipky MeSH
• RNA virová MeSH
• vakcíny proti chřipce * MeSH

BACKGROUND: Since 2011, the Global Influenza Hospital Surveillance Network (GIHSN) has used active surveillance to prospectively collect epidemiological and virological data on patients hospitalized with influenza virus infection. Here, we describe influenza virus strain circulation in the GIHSN participant countries during 2017-2018 season and examine factors associated with complicated hospitalization among patients admitted with laboratory-confirmed influenza illness. METHODS: The study enrolled patients who were hospitalized in a GIHSN hospital in the previous 48 h with acute respiratory symptoms and who had symptoms consistent with influenza within the 7 days before admission. Enrolled patients were tested by reverse transcription-polymerase chain reaction to confirm influenza virus infection. "Complicated hospitalization" was defined as a need for mechanical ventilation, admission to an intensive care unit, or in-hospital death. In each of four age strata (< 15, 15-< 50, 50-< 65, and ≥ 65 years), factors associated with complicated hospitalization in influenza-positive patients were identified by mixed effects logistic regression and those associated with length of hospital stay using a linear mixed-effects regression model. RESULTS: The study included 12,803 hospitalized patients at 14 coordinating sites in 13 countries, of which 4306 (34%) tested positive for influenza. Influenza viruses B/Yamagata, A/H3N2, and A/H1N1pdm09 strains dominated and cocirculated, although the dominant strains varied between sites. Complicated hospitalization occurred in 10.6% of influenza-positive patients. Factors associated with complicated hospitalization in influenza-positive patients included chronic obstructive pulmonary disease (15-< 50 years and ≥ 65 years), diabetes (15-< 50 years), male sex (50-< 65 years), hospitalization during the last 12 months (50-< 65 years), and current smoking (≥65 years). Chronic obstructive pulmonary disease (50-< 65 years), other chronic conditions (15-< 50 years), influenza A (50-< 65 years), and hospitalization during the last 12 months (< 15 years) were associated with a longer hospital stay. The proportion of patients with complicated influenza did not differ between influenza A and B. CONCLUSIONS: Complicated hospitalizations occurred in over 10% of patients hospitalized with influenza virus infection. Factors commonly associated with complicated or longer hospitalization differed by age group but commonly included chronic obstructive pulmonary disease, diabetes, and hospitalization during the last 12 months.

• Klíčová slova
• Epidemiology, Hospitalization, Influenza, Mortality, Risk factors,
• MeSH
• Betainfluenzavirus genetika   MeSH
• chřipka lidská epidemiologie   mortalita   virologie   MeSH
• délka pobytu MeSH
• dítě MeSH
• dospělí MeSH
• hospitalizace * MeSH
• jednotky intenzivní péče MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mortalita v nemocnicích MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• předškolní dítě MeSH
• prospektivní studie MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• umělé dýchání MeSH
• virus chřipky A, podtyp H1N1 genetika   MeSH
• virus chřipky A, podtyp H3N2 genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Neuraminidase is the main target for current influenza drugs. Reduced susceptibility to oseltamivir, the most widely prescribed neuraminidase inhibitor, has been repeatedly reported. The resistance substitutions I223V and S247N, alone or in combination with the major oseltamivir-resistance mutation H275Y, have been observed in 2009 pandemic H1N1 viruses. We overexpressed and purified the ectodomain of wild-type neuraminidase from the A/California/07/2009 (H1N1) influenza virus, as well as variants containing H275Y, I223V, and S247N single mutations and H275Y/I223V and H275Y/S247N double mutations. We performed enzymological and thermodynamic analyses and structurally examined the resistance mechanism. Our results reveal that the I223V or S247N substitution alone confers only a moderate reduction in oseltamivir affinity. In contrast, the major oseltamivir resistance mutation H275Y causes a significant decrease in the enzyme’s ability to bind this drug. Combination of H275Y with an I223V or S247N mutation results in extreme impairment of oseltamivir’s inhibition potency. Our structural analyses revealed that the H275Y substitution has a major effect on the oseltamivir binding pose within the active site while the influence of other studied mutations is much less prominent. Our crystal structures also helped explain the augmenting effect on resistance of combining H275Y with both substitutions.

• Klíčová slova
• crystal structure, influenza neuraminidase, isothermal titration calorimetry, oseltamivir, resistance,
• MeSH
• antivirové látky farmakologie   MeSH
• chřipka lidská virologie   MeSH
• inhibitory enzymů farmakologie   MeSH
• kalorimetrie MeSH
• kinetika MeSH
• krystalizace MeSH
• lidé MeSH
• missense mutace MeSH
• neuraminidasa chemie   genetika   MeSH
• oseltamivir farmakologie   MeSH
• replikace viru MeSH
• substituce aminokyselin MeSH
• termodynamika MeSH
• virová léková rezistence genetika   MeSH
• virové proteiny chemie   genetika   MeSH
• virus chřipky A, podtyp H1N1 účinky léků   enzymologie   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antivirové látky MeSH
• inhibitory enzymů MeSH
• neuraminidasa MeSH
• oseltamivir MeSH
• virové proteiny MeSH

AIM: To perform phylogenetic and molecular analysis of A/H1N1pdm influenza viruses isolated in the epidemic season 2012/2013 from hospitalised patients with symptoms of influenza-like illness (ILI). MATERIAL AND METHODS: The study set included 34 strains of the A/H1N1pdm influenza virus isolated in the Czech Republic in the epidemic season 2012/2013. The strains were analysed by partial or whole-genome sequencing. The genome segments were compared at the nucleotide and amino acid levels, absolute and percentage sequence identity were determined, and phylogenetic relations were identified. The last steps were the comparison of the H1 molecule with that of the most recent vaccine strain and identification of the genotypic structure and molecular markers linked to the pathogenicity and antiviral resistance. RESULTS: Phylogenetic analysis of the H1 molecule suggested that all 34 A/H1N1pdm isolates from the 2012/2013 season in the Czech Republic should be assigned to H1 group 6 divided into sublineages 6A and 6B. The comparison of the known antigenic regions of the H1 molecule with those in the most recent vaccine strain revealed two stable changes in antigenic regions Sb and Ca1. Furthermore, sporadic mutations were identified in antigenic regions Ca2, Cb, and Sb. Genotyping revealed co-circulation of two related but clearly distiguishable genotypes of A/H1N1pdm. All isolates showed sensitivity to oseltamivir. One strain consisted of two N1 sub-populations, one oseltamivir sensitive and the other oseltamivir resistant, in nearly equimolar proportions. CONCLUSION: All A/H1N1pdm isolates from the epidemic season 2012/2013 in the Czech Republic formed a phenotypically uniform group. At the nucleotide level, the divergence was relatively more pronounced and H1 sublineages and discrete genotypes were possible to identify. H1 molecules were highly identical to those of the vaccine strain A/California/7/2009 (H1N1) which showed that the current vaccine was protective enough. All strains were sensitive to oseltamivir; however, the selection of oseltamivir resistant N1 subpopulations was observed.

• MeSH
• časové faktory MeSH
• chřipka lidská epidemiologie   virologie   MeSH
• epidemie MeSH
• fylogeneze * MeSH
• hospitalizace MeSH
• lidé MeSH
• oseltamivir farmakologie   MeSH
• virová léková rezistence MeSH
• virus chřipky A, podtyp H1N1 klasifikace   účinky léků   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• oseltamivir MeSH

The global outbreak of novel A/H1N1 spread in human population worldwide has revealed an emergency need for producing a vaccine against this virus. Current influenza vaccines encounter problems with safety issues and weak response in high-risk population. It has been established that haemagglutinin is the most important viral antigen to which antibody responses are directed, and recombinant subunit vaccines, haemagglutinin of influenza A and B viruses, have been considered in order to facilitate vaccine production. In the present study, we have focused on construction of a recombinant baculovirus encoding the large subunit of novel influenza virus A/H1N1 haemagglutinin. The full genome of haemagglutinin was cloned into pGEM-TEasy vector and sequenced. The large subunit of the haemagglutinin gene was amplified by PCR using specific primers and cloned into pFast- BacHTc donor plasmid, which was then confirmed by restriction enzyme analysis and sequencing and transformed into E. coli DH10Bac competent cells. The bacmid DNA was transfected into insect cells to produce recombinant baculovirus. Expression of recombinant haemagglutinin in insect cells was determined by SDS-PAGE and immunoblotting. It has been shown that the recombinant haemagglutinin (rHA) obtained from the baculovirus insect cell expression system has suitable immunogenicity in human and can be considered as a candidate flu vac- cine. Here we produced large amounts of the HA1 protein of novel influenza A/H1N1 (Iranian isolate) in insect cells. The immunogenicity and efficacy of the recombinant HA1 will be evaluated as a vaccine candidate and compared to the recombinant HA1 produced in a prokaryotic system.

• MeSH
• Baculoviridae genetika   metabolismus   MeSH
• buněčné linie MeSH
• epitopy metabolismus   MeSH
• hemaglutininové glykoproteiny viru chřipky genetika   imunologie   metabolismus   MeSH
• imunoblotting MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• rekombinantní proteiny genetika   metabolismus   MeSH
• sekvenční analýza DNA MeSH
• Spodoptera genetika   virologie   MeSH
• transfekce MeSH
• virus chřipky A, podtyp H1N1 genetika   imunologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• epitopy MeSH
• hemaglutininové glykoproteiny viru chřipky MeSH
• rekombinantní proteiny MeSH

The NS1 protein of classical swine H1N1 influenza A virus evolved dynamically during the past 80 years, most notable changes happened in the four C-terminal sequences and the C-terminal truncation of 11 amino acids. However, the role of these changes on the virulence of classical swine H1N1 influenza A virus remains unknown. Using reverse genetics, three NS1 mutant viruses (RSEV, GSEI, and EPEV) and a wild-type virus (PEQK) were generated from A/Swine/Shanghai/1/2005 virus and the pathogenicity of the viruses was determined in mice. The results showed that RSEV and PEQK viruses could not infect the mice. By contrast, GSEI and EPEV viruses could replicate in the lungs of mice without prior adaptation. The viral titers in lungs from GSEI and EPEV virus-infected mice were 2,300 and 7 pfu/g at fourth-day post-infection, respectively. Mild-to-moderate alveolitis was observed in the histopathological test of lungs from GSEI and EPEV virus-infected mice. The results indicated that C-terminal GSEI and EPEV motifs of NS1 protein involved in viral virulence and facilitated the A/Swine/Shanghai/1/2005 virus crossing the species barrier from swine to mice.

• MeSH
• faktory virulence genetika   metabolismus   MeSH
• histocytochemie MeSH
• infekce viry z čeledi Orthomyxoviridae patologie   virologie   MeSH
• missense mutace * MeSH
• modely nemocí na zvířatech MeSH
• mutantní proteiny genetika   metabolismus   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• plíce patologie   virologie   MeSH
• replikace viru * MeSH
• reverzní genetika MeSH
• virová nálož MeSH
• virové nestrukturální proteiny genetika   metabolismus   MeSH
• virulence MeSH
• virus chřipky A, podtyp H1N1 genetika   patogenita   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• faktory virulence MeSH
• INS1 protein, influenza virus MeSH Prohlížeč
• mutantní proteiny MeSH
• virové nestrukturální proteiny MeSH