In the shadow of SARS-CoV-2, influenza seems to be an innocent virus, although new zoonotic influenza viruses evolved by mutations may lead to severe pandemics. According to WHO, there is an urgent need for better antiviral drugs. Blocking viral hemagglutinin with multivalent N-acetylneuraminic acid derivatives is a promising approach to prevent influenza infection. Moreover, dual inhibition of both hemagglutinin and neuraminidase may result in a more powerful effect. Since both viral glycoproteins can bind to neuraminic acid, we have prepared three series of amphiphilic self-assembling 2-thio-neuraminic acid derivatives constituting aggregates in aqueous medium to take advantage of their multivalent effect. One of the series was prepared by the azide-alkyne click reaction, and the other two by the thio-click reaction to yield neuraminic acid derivatives containing lipophilic tails of different sizes and an enzymatically stable thioglycosidic bond. Two of the three bis-octyl derivatives produced proved to be active against influenza viruses, while all three octyl derivatives bound to hemagglutinin and neuraminidase from H1N1 and H3N2 influenza types.

• MeSH
• chřipka lidská * farmakoterapie   MeSH
• hemaglutininové glykoproteiny viru chřipky metabolismus   MeSH
• hemaglutininy farmakologie   MeSH
• kyselina N-acetylneuraminová farmakologie   metabolismus   MeSH
• kyseliny neuraminové MeSH
• lidé MeSH
• neuraminidasa metabolismus   MeSH
• virus chřipky A, podtyp H1N1 * MeSH
• virus chřipky A, podtyp H3N2 MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BackgroundTimely treatment with neuraminidase inhibitors (NAI) can reduce severe outcomes in influenza patients.AimWe assessed the impact of antiviral treatment on in-hospital deaths of laboratory-confirmed influenza patients in 11 European Union countries from 2010/11 to 2019/20.MethodsCase-based surveillance data from hospitalised patients with known age, sex, outcome, ward, vaccination status, timing of antiviral treatment, and hospitalisation were obtained. A mixed effect logistic regression model using country as random intercept was applied to estimate the adjusted odds ratio (aOR) for in-hospital death in patients treated with NAIs vs not treated.ResultsOf 19,937 patients, 31% received NAIs within 48 hours of hospital admission. Older age (60-79 years aOR 3.0, 95% CI: 2.4-3.8; 80 years 8.3 (6.6-10.5)) and intensive care unit admission (3.8, 95% CI: 3.4-4.2) increased risk of dying, while early hospital admission after symptom onset decreased risk (aOR 0.91, 95% CI: 0.90-0.93). NAI treatment initiation within 48 hours and up to 7 days reduced risk of dying (0-48 hours aOR 0.51, 95% CI: 0.45-0.59; 3-4 days 0.59 (0.51-0.67); 5-7 days 0.64 (0.56-0.74)), in particular in patients 40 years and older (e.g. treatment within 48 hours: 40-59 years aOR 0.43, 95% CI: 0.28-0.66; 60-79 years 0.50 (0.39-0.63); ≥80 years 0.51 (0.42-0.63)).ConclusionNAI treatment given within 48 hours and possibly up to 7 days after symptom onset reduced risk of in-hospital death. NAI treatment should be considered in older patients to prevent severe outcomes.

• MeSH
• antivirové látky terapeutické užití   MeSH
• chřipka lidská * farmakoterapie   epidemiologie   MeSH
• guanidiny terapeutické užití   MeSH
• inhibitory enzymů terapeutické užití   MeSH
• lidé MeSH
• mortalita v nemocnicích MeSH
• neuraminidasa MeSH
• oseltamivir * terapeutické užití   MeSH
• senioři MeSH
• výsledek terapie MeSH
• zanamivir terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH

This study focuses on design, synthesis and in vitro evaluation of inhibitory potency of two series of sialylmimetic that target an exosite ("150-cavity") adjacent to the active site of influenza neuraminidases from A/California/07/2009 (H1N1) pandemic strain and A/chicken/Nakorn-Patom/Thailand/CU-K2-2004 (H5N1). The structure-activity analysis as well as 3-D structure of the complex of parental compound with the pandemic neuraminidase p09N1 revealed high flexibility of the 150-cavity towards various modification of the neuraminidase inhibitors. Furthermore, our comparison of two methods for inhibition constant determination performed at slightly different pH values suggest that the experimental conditions of the measurement could dramatically influence the outcome of the analysis in the compound-dependent manner. Therefore, previously reported Ki values determined at non-physiological pH should be carefully scrutinized.

• MeSH
• lidé MeSH
• neuraminidasa farmakologie   terapeutické užití   MeSH
• oseltamivir farmakologie   terapeutické užití   MeSH
• virus chřipky A, podtyp H1N1 patogenita   MeSH
• virus chřipky A, podtyp H5N1 patogenita   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Influenza neuraminidase is responsible for the escape of new viral particles from the infected cell surface. Several neuraminidase inhibitors are used clinically to treat patients or stockpiled for emergencies. However, the increasing development of viral resistance against approved inhibitors has underscored the need for the development of new antivirals effective against resistant influenza strains. A facile, sensitive, and inexpensive screening method would help achieve this goal. Recently, we described a multiwell plate-based DNA-linked inhibitor antibody assay (DIANA). This highly sensitive method can quantify femtomolar concentrations of enzymes. DIANA also has been applied to high-throughput enzyme inhibitor screening, allowing the evaluation of inhibition constants from a single inhibitor concentration. Here, we report the design, synthesis, and structural characterization of a tamiphosphor derivative linked to a reporter DNA oligonucleotide for the development of a DIANA-type assay to screen potential influenza neuraminidase inhibitors. The neuraminidase is first captured by an immobilized antibody, and the test compound competes for binding to the enzyme with the oligo-linked detection probe, which is then quantified by qPCR. We validated this novel assay by comparing it with the standard fluorometric assay and demonstrated its usefulness for sensitive neuraminidase detection as well as high-throughput screening of potential new neuraminidase inhibitors.

• MeSH
• antivirové látky chemie   farmakologie   MeSH
• chřipka lidská farmakoterapie   enzymologie   virologie   MeSH
• DNA chemie   MeSH
• inhibitory enzymů chemie   farmakologie   MeSH
• kyseliny fosforité chemie   MeSH
• lidé MeSH
• neuraminidasa antagonisté a inhibitory   metabolismus   MeSH
• oseltamivir analogy a deriváty   chemie   MeSH
• preklinické hodnocení léčiv metody   MeSH
• reprodukovatelnost výsledků MeSH
• virové proteiny antagonisté a inhibitory   metabolismus   MeSH
• virus chřipky A účinky léků   enzymologie   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Thrombotic microangiopathy (TMA) refers to phenotypically similar disorders, including hemolytic uremic syndromes (HUS) and thrombotic thrombocytopenic purpura (TTP). This review explores the role of the influenza virus as trigger of HUS or TTP. We conducted a literature survey in PubMed and Google Scholar using HUS, TTP, TMA, and influenza as keywords, and extracted and analyzed reported epidemiological and clinical data. We identified 25 cases of influenza-associated TMA. Five additional cases were linked to influenza vaccination and analyzed separately. Influenza A was found in 83%, 10 out of 25 during the 2009 A(H1N1) pandemic. Two patients had bona fide TTP with ADAMTS13 activity <10%. Median age was 15 years (range 0.5-68 years), two thirds were male. Oligoanuria was documented in 81% and neurological involvement in 40% of patients. Serum C3 was reduced in 5 out of 14 patients (36%); Coombs test was negative in 7 out of 7 and elevated fibrin/fibrinogen degradation products were documented in 6 out of 8 patients. Pathogenic complement gene mutations were found in 7 out of 8 patients tested (C3, MCP, or MCP combined with CFB or clusterin). Twenty out of 24 patients recovered completely, but 3 died (12%). Ten of the surviving patients underwent plasma exchange (PLEX) therapy, 5 plasma infusions. Influenza-mediated HUS or TTP is rare. A sizable proportion of tested patients demonstrated mutations associated with alternative pathway of complement dysregulation that was uncovered by this infection. Further research is warranted targeting the roles of viral neuraminidase, enhanced virus-induced complement activation and/or ADAMTS13 antibodies, and rational treatment approaches.

• MeSH
• alternativní dráha komplementu genetika   imunologie   MeSH
• anurie epidemiologie   etiologie   terapie   MeSH
• atypický hemolyticko-uremický syndrom epidemiologie   etiologie   imunologie   terapie   MeSH
• chřipka lidská komplikace   imunologie   prevence a kontrola   MeSH
• ledviny krevní zásobení   imunologie   patologie   MeSH
• lidé MeSH
• mikrocévy imunologie   patologie   MeSH
• mutace MeSH
• neuraminidasa imunologie   MeSH
• oligurie epidemiologie   etiologie   terapie   MeSH
• protein ADAMTS13 imunologie   metabolismus   MeSH
• trombotická trombocytopenická purpura epidemiologie   etiologie   imunologie   terapie   MeSH
• vakcíny proti chřipce škodlivé účinky   MeSH
• virové proteiny imunologie   MeSH
• virus chřipky A imunologie   MeSH
• výměna plazmy MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy 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.

• 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

• MeSH
• aniliny terapeutické užití   MeSH
• chinoliny terapeutické užití   MeSH
• Evropská unie MeSH
• ftalaziny terapeutické užití   MeSH
• heterocyklické sloučeniny klasifikace   terapeutické užití   MeSH
• indoly terapeutické užití   MeSH
• infliximab terapeutické užití   MeSH
• lidé MeSH
• mezinárodní agentury MeSH
• močovina analogy a deriváty   terapeutické užití   MeSH
• morfoliny terapeutické užití   MeSH
• neuraminidasa antagonisté a inhibitory   terapeutické užití   MeSH
• nitrily terapeutické užití   MeSH
• piperaziny terapeutické užití   MeSH
• přehodnocení terapeutických indikací léčivého přípravku * metody   trendy   využití   MeSH
• schvalování léčiv * MeSH
• trastuzumab terapeutické užití   MeSH
• Check Tag
• lidé MeSH

• MeSH
• adamantan farmakokinetika   farmakologie   terapeutické užití   MeSH
• antimetabolity farmakokinetika   farmakologie   terapeutické užití   MeSH
• antivirové látky * farmakokinetika   farmakologie   terapeutické užití   MeSH
• chřipka lidská farmakoterapie   klasifikace   MeSH
• herpetické infekce farmakoterapie   klasifikace   MeSH
• humanizované monoklonální protilátky terapeutické užití   MeSH
• inhibitory enzymů terapeutické užití   MeSH
• koronavirové infekce MeSH
• lidé MeSH
• lidský respirační syncytiální virus účinky léků   MeSH
• nemoci dýchací soustavy * etiologie   farmakoterapie   MeSH
• neuraminidasa aplikace a dávkování   MeSH
• nukleosidy farmakokinetika   farmakologie   terapeutické užití   MeSH
• Orthomyxoviridae účinky léků   MeSH
• virus SARS účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

• MeSH
• antivirové látky terapeutické užití   MeSH
• chřipka lidská * diagnóza   epidemiologie   prevence a kontrola   MeSH
• epidemický výskyt choroby prevence a kontrola   statistika a číselné údaje   MeSH
• hromadná vakcinace MeSH
• lidé MeSH
• neuraminidasa * antagonisté a inhibitory   terapeutické užití   MeSH
• prevalence MeSH
• rizikové faktory MeSH
• surveillance populace MeSH
• vakcíny proti chřipce škodlivé účinky   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH
• Geografické názvy
• Německo MeSH

Influenza virus causes severe respiratory infections that are responsible for up to half a million deaths worldwide each year. Two inhibitors targeting viral neuraminidase have been approved to date (oseltamivir, zanamivir). However, the rapid development of antiviral drug resistance and the efficient transmission of resistant viruses among humans represent serious threats to public health. The approved influenza neuraminidase inhibitors have (oxa)cyclohexene scaffolds designed to mimic the oxonium transition state during enzymatic cleavage of sialic acid. Their active forms contain a carboxylate that interacts with three arginine residues in the enzyme active site. Recently, the phosphonate group was successfully used as an isostere of the carboxylate in oseltamivir, and the resulting compound, tamiphosphor, was identified as a highly active neuraminidase inhibitor. However, the structure of the complex of this promising inhibitor with neuraminidase has not yet been reported. Here, we analyzed the interaction of a set of oseltamivir and tamiphosphor derivatives with neuraminidase from the A/California/07/2009 (H1N1) influenza virus. We thermodynamically characterized the binding of oseltamivir carboxylate or tamiphosphor to the neuraminidase catalytic domain by protein microcalorimetry, and we determined crystal structure of the catalytic domain in complex with tamiphosphor at 1.8 Å resolution. This structural information should aid rational design of the next generation of neuraminidase inhibitors.

• MeSH
• antivirové látky chemie   farmakologie   MeSH
• chřipka lidská virologie   MeSH
• inhibitory enzymů chemie   farmakologie   MeSH
• katalytická doména MeSH
• kinetika MeSH
• kyseliny fosforité metabolismus   terapeutické užití   MeSH
• lidé MeSH
• neuraminidasa antagonisté a inhibitory   metabolismus   MeSH
• oseltamivir analogy a deriváty   metabolismus   terapeutické užití   MeSH
• pandemie MeSH
• termodynamika MeSH
• vazba proteinů MeSH
• virus chřipky A, podtyp H1N1 enzymologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH