The mechanism by which DNA viruses interact with different DNA sensors and their connection with the activation of interferon (IFN) type I pathway are poorly understood. We investigated the roles of protein 204 (p204) and cyclic guanosine-adenosine synthetase (cGAS) sensors during infection with mouse polyomavirus (MPyV). The phosphorylation of IFN regulatory factor 3 (IRF3) and the stimulator of IFN genes (STING) proteins and the upregulation of IFN beta (IFN-β) and MX Dynamin Like GTPase 1 (MX-1) genes were detected at the time of replication of MPyV genomes in the nucleus. STING knockout abolished the IFN response. Infection with a mutant virus that exhibits defective nuclear entry via nucleopores and that accumulates in the cytoplasm confirmed that replication of viral genomes in the nucleus is required for IFN induction. The importance of both DNA sensors, p204 and cGAS, in MPyV-induced IFN response was demonstrated by downregulation of the IFN pathway observed in p204-knockdown and cGAS-knockout cells. Confocal microscopy revealed the colocalization of p204 with MPyV genomes in the nucleus. cGAS was found in the cytoplasm, colocalizing with viral DNA leaked from the nucleus and with DNA within micronucleus-like bodies, but also with the MPyV genomes in the nucleus. However, 2'3'-Cyclic guanosine monophosphate-adenosine monophosphate synthesized by cGAS was detected exclusively in the cytoplasm. Biochemical assays revealed no evidence of functional interaction between cGAS and p204 in the nucleus. Our results provide evidence for the complex interactions of MPyV and DNA sensors including the sensing of viral genomes in the nucleus by p204 and of leaked viral DNA and micronucleus-like bodies in the cytoplasm by cGAS.

• Klíčová slova
• cGAS sensor, immune sensing of DNA, mouse polyomavirus, p204 sensor, pattern recognition receptors,
• MeSH
• DNA virů genetika   imunologie   MeSH
• fosfoproteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• fosforylace MeSH
• infekce onkogenními viry imunologie   virologie   MeSH
• interakce hostitele a patogenu MeSH
• interferon beta metabolismus   MeSH
• jaderné proteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• membránové proteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• myši MeSH
• nukleotidyltransferasy antagonisté a inhibitory   genetika   metabolismus   MeSH
• polyomavirové infekce imunologie   virologie   MeSH
• Polyomavirus genetika   imunologie   MeSH
• přirozená imunita imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cGAS protein, mouse MeSH Prohlížeč
• DNA virů MeSH
• fosfoproteiny MeSH
• Ifi16 protein, mouse MeSH Prohlížeč
• interferon beta MeSH
• jaderné proteiny MeSH
• membránové proteiny MeSH
• nukleotidyltransferasy MeSH
• Sting1 protein, mouse MeSH Prohlížeč

The increasing use of neonicotinoids in systematic seed treatment to crops is a serious cause of pollution of water resources and environment. Consequently, food sources can get eventually contaminated. To this end, it is desirable to develop suitable and effective platforms in order to obtain low-cost and sensitive sensors for neonicotinoids detection. In this work, graphene oxide modified electrodes were used as highly efficient electrochemical sensors for detection of two common insecticides - thiamethoxam and imidacloprid. The proposed sensor responded linearly in the concentration range of 10-200µmolL-1 for both analytes and the detection limits were determined as low as 8.3µmolL-1 and 7.9µmolL-1 for thiamethoxam and imidacloprid, respectively. Analytical performance was also evaluated on spiked water and honey samples.

• Klíčová slova
• Graphene oxide, Imidacloprid, Neonicotinoids, Thiamethoxam, Voltammetry,
• MeSH
• analýza potravin ekonomika   metody   MeSH
• biosenzitivní techniky ekonomika   metody   MeSH
• chemické látky znečišťující vodu analýza   MeSH
• dusíkaté sloučeniny analýza   MeSH
• elektrochemické techniky ekonomika   metody   MeSH
• elektrody MeSH
• grafit chemie   MeSH
• imidazoly analýza   MeSH
• insekticidy analýza   MeSH
• kontaminace potravin analýza   MeSH
• limita detekce MeSH
• med analýza   MeSH
• monitorování životního prostředí ekonomika   metody   MeSH
• neonikotinoidy MeSH
• oxaziny analýza   MeSH
• oxidy chemie   MeSH
• řeky chemie   MeSH
• thiamethoxam MeSH
• thiazoly analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• dusíkaté sloučeniny MeSH
• grafit MeSH
• imidacloprid MeSH Prohlížeč
• imidazoly MeSH
• insekticidy MeSH
• neonikotinoidy MeSH
• oxaziny MeSH
• oxidy MeSH
• thiamethoxam MeSH
• thiazoly MeSH

In this study, an innovative nanocomposite of multiwalled carbon nanotubes (MWCNTs), copper oxide nanoparticles (CuONPs) and lignin (LGN) polymer were successfully synthesized and used to modify the glassy carbon electrode for the determination of chlorogenic acid (CGA). Cyclic voltammetry (CV) emphasised a quasi-reversible, adsorption controlled and pH dependent electrode procedure. In cyclic voltammetry a pair of well distinct redox peaks of CGA were observed at the LGN-MWCNTs-CuONPs-GCE in 0.1 M phosphate buffer solution (PBS), at pH 2. The synthesized nanoparticles and nanocomposites were characterized by Fourier transformation infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and x-ray diffraction (XRD) analyses. Differential pulse voltammetry (DPV) was applied to the anodic peak and used for the quantitative detection of CGA. Under optimal conditions, the proposed sensor showed linear responses from 5 μM to 50 μM, the linear regression equation Ipa (μA) = 2.6074 C-5.1027 (R2 = 0.995), whilst the limit of detection (LOD) and limit of quantifications (LOQ) were found to be 0.0125 μM and 0.2631 μM respectively. The LGN-MWCNTs-CuONPs-GCE were applied to detect the CGA in real coffee samples with the recovery ranging from 97 to 106 %. The developed sensor was successfully applied for the analysis of CGA content in the coffee samples. In addition, electrophilic, nucleophilic reactions and chlorogenic acid docking studies were carried out to better understand the redox mechanisms and were supported by density functional theory calculations.

• Klíčová slova
• Analytical chemistry, Electrochemistry, Materials chemistry,
• Publikační typ
• časopisecké články MeSH

DNA virus infections are often lifelong and can cause serious diseases in their hosts. Their recognition by the sensors of the innate immune system represents the front line of host defence. Understanding the molecular mechanisms of innate immunity responses is an important prerequisite for the design of effective antivirotics. This review focuses on the present state of knowledge surrounding the mechanisms of viral DNA genome sensing and the main induced pathways of innate immunity responses. The studies that have been performed to date indicate that herpesviruses, adenoviruses, and polyomaviruses are sensed by various DNA sensors. In non-immune cells, STING pathways have been shown to be activated by cGAS, IFI16, DDX41, or DNA-PK. The activation of TLR9 has mainly been described in pDCs and in other immune cells. Importantly, studies on herpesviruses have unveiled novel participants (BRCA1, H2B, or DNA-PK) in the IFI16 sensing pathway. Polyomavirus studies have revealed that, in addition to viral DNA, micronuclei are released into the cytosol due to genotoxic stress. Papillomaviruses, HBV, and HIV have been shown to evade DNA sensing by sophisticated intracellular trafficking, unique cell tropism, and viral or cellular protein actions that prevent or block DNA sensing. Further research is required to fully understand the interplay between viruses and DNA sensors.

• Klíčová slova
• DNA sensing, DNA viruses, IFI16, IFN, STING, TLR9, cGAS, inflammasome, innate immunity, p204/Ifi-204,
• MeSH
• DNA virů metabolismus   MeSH
• Herpesviridae * genetika   metabolismus   MeSH
• infekce DNA virem * MeSH
• lidé MeSH
• Polyomavirus * genetika   MeSH
• přirozená imunita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• DNA virů MeSH

Chronic hepatitis B virus (HBV) infection is a major cause of chronic liver disease and cancer worldwide. The mechanisms of viral genome sensing and the evasion of innate immune responses by HBV infection are still poorly understood. Recently, the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) was identified as a DNA sensor. In this study, we investigated the functional role of cGAS in sensing HBV infection and elucidate the mechanisms of viral evasion. We performed functional studies including loss-of-function and gain-of-function experiments combined with cGAS effector gene expression profiling in an infectious cell culture model, primary human hepatocytes, and HBV-infected human liver chimeric mice. Here, we show that cGAS is expressed in the human liver, primary human hepatocytes, and human liver chimeric mice. While naked relaxed-circular HBV DNA is sensed in a cGAS-dependent manner in hepatoma cell lines and primary human hepatocytes, host cell recognition of viral nucleic acids is abolished during HBV infection, suggesting escape from sensing, likely during packaging of the genome into the viral capsid. While the hepatocyte cGAS pathway is functionally active, as shown by reduction of viral covalently closed circular DNA levels in gain-of-function studies, HBV infection suppressed cGAS expression and function in cell culture models and humanized mice. Conclusion: HBV exploits multiple strategies to evade sensing and antiviral activity of cGAS and its effector pathways.

• MeSH
• buněčné kultury MeSH
• DNA virů imunologie   MeSH
• hepatitida B imunologie   patofyziologie   MeSH
• hepatocyty metabolismus   virologie   MeSH
• hybridizace in situ fluorescenční metody   MeSH
• imunitní únik imunologie   fyziologie   MeSH
• interakce hostitele a patogenu MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• myši MeSH
• nukleotidy cyklické metabolismus   MeSH
• stanovení celkové genové exprese metody   MeSH
• virus hepatitidy B patogenita   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• cyclic guanosine monophosphate-adenosine monophosphate MeSH Prohlížeč
• DNA virů MeSH
• nukleotidy cyklické MeSH