Diseases caused by pathogens contribute to molecular adaptations in host immunity. Variety of viral pathogens challenging animal immunity can drive positive selection diversifying receptors recognising the infections. However, whether distinct virus sensing systems differ across animals in their evolutionary modes remains unclear. Our review provides a comparative overview of natural selection shaping molecular evolution in vertebrate viral-binding pattern recognition receptors (PRRs). Despite prevailing negative selection arising from the functional constraints, multiple lines of evidence now suggest diversifying selection in the Toll-like receptors (TLRs), NOD-like receptors (NLRs), RIG-I-like receptors (RLRs) and oligoadenylate synthetases (OASs). In several cases, location of the positively selected sites in the ligand-binding regions suggests effects on viral detection although experimental support is lacking. Unfortunately, in most other PRR families including the AIM2-like receptor family, C-type lectin receptors (CLRs), and cyclic GMP-AMP synthetase studies characterising their molecular evolution are rare, preventing comparative insight. We indicate shared characteristics of the viral sensor evolution and highlight priorities for future research.

• Klíčová slova
• Evolutionary adaptation, Innate immunity, Molecular evolution, Pattern recognition receptor, Positive selection, Virus detection,
• MeSH
• molekulární evoluce MeSH
• obratlovci MeSH
• přirozená imunita * MeSH
• receptory rozpoznávající vzory * genetika   MeSH
• selekce (genetika) MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• receptory rozpoznávající vzory * 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

Retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated protein 5 (MDA5) are key RNA virus sensors belonging to the RIG-I-like receptor (RLR) family. The activation of the RLR inflammasome leads to the establishment of antiviral state, mainly through interferon-mediated signaling. The evolutionary dynamics of RLRs has been studied mainly in mammals, where rare cases of RLR gene losses were described. By in silico screening of avian genomes, we previously described two independent disruptions of MDA5 in two bird orders. Here, we extend this analysis to approximately 150 avian genomes and report 16 independent evolutionary events of RIG-I inactivation. Interestingly, in almost all cases, these inactivations are coupled with genetic disruptions of RIPLET/RNF135, an ubiquitin ligase RIG-I regulator. Complete absence of any detectable RIG-I sequences is unique to several galliform species, including the domestic chicken (Gallus gallus). We further aimed to determine compensatory evolution of MDA5 in RIG-I-deficient species. While we were unable to show any specific global pattern of adaptive evolution in RIG-I-deficient species, in galliforms, the analyses of positive selection and surface charge distribution support the hypothesis of some compensatory evolution in MDA5 after RIG-I loss. This work highlights the dynamic nature of evolution in bird RNA virus sensors.

• Klíčová slova
• avian genome, gene loss, innate immunity, viral sensors,
• MeSH
• antivirové látky MeSH
• DEAD box protein 58 genetika   metabolismus   MeSH
• přirozená imunita MeSH
• ptáci virologie   MeSH
• RNA-helikasy MeSH
• RNA-viry * fyziologie   MeSH
• RNA * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antivirové látky MeSH
• DEAD box protein 58 MeSH
• RNA-helikasy MeSH
• RNA * MeSH

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 aim of the presented study was to assess the effect of a single administration of Fe(3+)-dextran on immune cell counts and pterin biomolecule production as novel sensors of the piglets' immune system activation, and to determine concentrations of cortisol, a traditional hormonal biosensor of the stress response. Pterins (neopterin and biopterin) in the piglets' blood serum were analyzed by separation using reversed-phase HPLC. A single dose of Fe(3+)-dextran produced a special stress situation in the piglets' organism which manifested itself by an increased production of neopterin (p < 0.05) and biopterin (p < 0.01) in the experimental piglets. Changes in cortisol concentrations and leukocyte counts were influenced by handling stress and were not specifically correlated to iron dextran application. Iron concentrations in the internal environment of the experimental piglets' group were higher by an order of magnitude compared with the controls, and the highest serum concentrations of iron (p < 0.01) were reached 24 h following Fe(3+)-dextran administration. The data presented offer a new perspective on the evaluation of stress situations in the animal organism and, not least importantly, extends the rather modest current list of references on the role of pterins in livestock animals.

• Klíčová slova
• biopterin, cortisol, iron, leukogram, neopterin,
• MeSH
• biologické markery krev   MeSH
• fyziologický stres účinky léků   imunologie   MeSH
• hydrokortison krev   MeSH
• prasata MeSH
• přirozená imunita účinky léků   imunologie   MeSH
• pteriny krev   imunologie   MeSH
• železo farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• hydrokortison MeSH
• pteriny MeSH
• železo MeSH

The development of clinically applicable portable sensors and multiplex protein biomarker assays is one of the most important goals of laboratory medicine today. Sensing strategies based on electrochemical devices are discussed in this overview, with special emphasis on detection principles derived from voltammetry, electrogenerated chemiluminescence, bipolar electrochemistry and impedance-based measurements. Up-to-date examples of electrochemical methods in biomedical research and development are highlighted here, including critical evaluation and future directions of the analysis, development and validation of new protein biomarkers.

• Klíčová slova
• bioaffinity assay, biosensor, detection surface, immobilization, immunoassay, microelectrode, microelectronic devices,
• MeSH
• biologické markery analýza   MeSH
• biosenzitivní techniky metody   MeSH
• elektrochemické techniky metody   MeSH
• lidé MeSH
• mikročipová analýza metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické markery MeSH

• MeSH
• analýza potravin přístrojové vybavení   MeSH
• biologické markery chemie   metabolismus   MeSH
• lidé MeSH
• monitorování životního prostředí přístrojové vybavení   MeSH
• povrchová plasmonová rezonance přístrojové vybavení   metody   trendy   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• biologické markery MeSH

Real-time detection and nanoscale imaging of human immunodeficiency virus type 1 ribonucleic acid (HIV-1 RNA) in latently infected cells that persist in people living with HIV-1 on antiretroviral therapy in blood and tissue may reveal new insights needed to cure HIV-1 infection. Herein, we develop a strategy combining DNA nanotechnology and super-resolution expansion microscopy (ExM) to detect and image a 22 base sequence transcribed from the HIV-1 promoter in model live and fixed cells. We engineer a chimeric locked nucleic acid (LNA)-DNA sensor via hybridization chain reaction to probe HIV-1 RNA in the U3 region of the HIV-1 long terminal repeat (LTR) by signal amplification in live cells. We find that the viral RNA transcript of the U3 region of the HIV-1 LTR, namely PromA, is a valid and specific biomarker to detect infected live cells. The efficiency and selectivity of the LNA-DNA sensor are evaluated in combination with ExM. Unlike standard ExM methods, which rely on additional custom linkers to anchor and immobilize RNA molecules in the intracellular polymeric network, in the current strategy, we probe and image the HIV-1 RNA target at nanoscale resolution, without resorting to chemical linkers or additional preparation steps. This is achieved by physical entrapment of the HIV-1 viral transcripts in the cells post-expansion by finely tuning the mesh size of the intracellular polymeric network.

• MeSH
• DNA MeSH
• HIV-1 * genetika   MeSH
• lidé MeSH
• oligonukleotidy MeSH
• RNA virová genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA MeSH
• locked nucleic acid MeSH Prohlížeč
• oligonukleotidy MeSH
• RNA virová MeSH

Two key cytosolic receptors belonging to the retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) family sense the viral RNA-derived danger signals: RIG-I and melanoma differentiation-associated protein 5 (MDA5). Their activation establishes an antiviral state by downstream signaling that ultimately activates interferon-stimulated genes (ISGs). While in rare cases RIG-I gene loss has been detected in mammalian and avian species, most notably in the chicken, MDA5 pseudogenization has only been detected once in mammals. We have screened over a hundred publicly available avian genome sequences and describe an independent disruption of MDA5 in two unrelated avian lineages, the storks (Ciconiiformes) and the rallids (Gruiformes). The results of our RELAX analysis confirmed the absence of negative selection in the MDA5 pseudogene. In contrast to our prediction, we have shown, using multiple dN/dS-based approaches, that the MDA5 loss does not appear to have resulted in any compensatory evolution in the RIG-I gene, which may partially share its ligand-binding specificity. Together, our results indicate that the MDA5 pseudogenization may have important functional effects on immune responsiveness in these two avian clades.

• Klíčová slova
• avian genome, gene loss, innate immunity, viral sensors,
• MeSH
• DEAD box protein 58 chemie   genetika   imunologie   MeSH
• delece genu * MeSH
• fylogeneze MeSH
• lidé MeSH
• molekulární modely MeSH
• přirozená imunita MeSH
• pseudogeny MeSH
• ptačí proteiny chemie   genetika   imunologie   MeSH
• ptáci klasifikace   genetika   imunologie   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DEAD box protein 58 MeSH
• ptačí proteiny MeSH

Shortly after entering the cell, HIV-1 copies its genomic RNA into double-stranded DNA in a process known as reverse transcription. This process starts inside a core consisting of an enclosed lattice of capsid proteins that protect the viral RNA from cytosolic sensors and degradation pathways. To accomplish reverse transcription and integrate cDNA into the host cell genome, the capsid shell needs to be disassembled, or uncoated. Premature or delayed uncoating attenuates reverse transcription and blocks HIV-1 infectivity. Small molecules that bind to the capsid lattice of the HIV-1 core and either destabilize or stabilize its structure could thus function as effective HIV-1 inhibitors. To screen for such compounds, we modified our recently developed FAITH assay to allow direct assessment of the stability of in vitro preassembled HIV-1 capsid-nucleocapsid (CANC) tubular particles. This new assay is a high-throughput fluorescence method based on measuring the amount of nucleic acid released from CANC complexes under disassembly conditions. The amount of disassembled CANC particles and released nucleic acid is proportional to the fluorescence signal, from which the relative percentage of CANC stability can be calculated. We consider our assay a potentially powerful tool for in vitro screening for compounds that alter HIV disassembly.

• MeSH
• HIV infekce farmakoterapie   MeSH
• HIV-1 účinky léků   fyziologie   MeSH
• látky proti HIV chemie   izolace a purifikace   farmakologie   MeSH
• lidé MeSH
• nukleokapsida analýza   účinky léků   MeSH
• proteiny virového jádra chemie   genetika   metabolismus   MeSH
• RNA virová genetika   MeSH
• rychlé screeningové testy MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• svlékání virového obalu účinky léků   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• látky proti HIV MeSH
• proteiny virového jádra MeSH
• RNA virová MeSH