Tick-borne encephalitis virus (TBEV), of the genus Flavivirus, is a causative agent of severe encephalitis in regions of endemicity of northern Asia and central and northern Europe. Interferon-induced transmembrane proteins (IFITMs) are restriction factors that inhibit the replication cycles of numerous viruses, including flaviviruses such as West Nile virus, dengue virus, and Zika virus. Here, we demonstrate the role of IFITM1, IFITM2, and IFITM3 in the inhibition of TBEV infection and in protection against virus-induced cell death. We show that the most significant role is that of IFITM3, including the dissection of its functional motifs by mutagenesis. Furthermore, through the use of CRISPR-Cas9-generated IFITM1/3-knockout monoclonal cell lines, we confirm the role and additive action of endogenous IFITMs in TBEV suppression. However, the results of coculture assays suggest that TBEV might partially escape interferon- and IFITM-mediated suppression during high-density coculture infection when the virus enters naive cells directly from infected donor cells. Thus, cell-to-cell spread may constitute a strategy for virus escape from innate host defenses. IMPORTANCE TBEV infection may result in encephalitis, chronic illness, or death. TBEV is endemic in northern Asia and Europe; however, due to climate change, new centers of endemicity have arisen. Although effective TBEV vaccines have been approved, vaccination coverage is low, and due to the lack of specific therapeutics, infected individuals depend on their immune responses to control the infection. IFITM proteins are components of the innate antiviral defenses that suppress cell entry of many viral pathogens. However, no studies on the role of IFITM proteins in TBEV infection have been published thus far. Understanding antiviral innate immune responses is crucial for the future development of antiviral strategies. Here, we show the important role of IFITM proteins in the inhibition of TBEV infection and virus-mediated cell death. However, our data suggest that TBEV cell-to-cell spread may be less prone to both interferon- and IFITM-mediated suppression, potentially facilitating escape from IFITM-mediated immunity.
- MeSH
- buněčné linie MeSH
- cytopatogenní efekt virový MeSH
- exprese genu MeSH
- genový knockdown MeSH
- interakce hostitele a patogenu * genetika imunologie MeSH
- interakční proteinové domény a motivy MeSH
- interferony metabolismus MeSH
- klíšťová encefalitida genetika imunologie metabolismus virologie MeSH
- lidé MeSH
- membránové proteiny chemie genetika metabolismus MeSH
- multigenová rodina MeSH
- náchylnost k nemoci MeSH
- odolnost vůči nemocem genetika imunologie MeSH
- replikace viru MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- viry klíšťové encefalitidy fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Inflammation is an integral part of defense against most infectious diseases. These pathogen-induced immune responses are in very many instances strongly influenced by host's sex. As a consequence, sexual dimorphisms were observed in susceptibility to many infectious diseases. They are pathogen dose-dependent, and their outcomes depend on pathogen and even on its species or subspecies. Sex may differentially affect pathology of various organs and its influence is modified by interaction of host's hormonal status and genotype: sex chromosomes X and Y, as well as autosomal genes. In this Mini Review we summarize the major influences of sex in human infections and subsequently focus on 22 autosomal genes/loci that modify in a sex-dependent way the response to infectious diseases in mouse models. These genes have been observed to influence susceptibility to viruses, bacteria, parasites, fungi and worms. Some sex-dependent genes/loci affect susceptibility only in females or only in males, affect both sexes, but have stronger effect in one sex; still other genes were shown to affect the disease in both sexes, but with opposite direction of effect in females and males. The understanding of mechanisms of sex-dependent differences in the course of infectious diseases may be relevant for their personalized management.
- MeSH
- bakteriální infekce epidemiologie genetika MeSH
- biologické modely MeSH
- dítě MeSH
- dospělí MeSH
- druhová specificita MeSH
- genetická predispozice k nemoci * MeSH
- helmintóza epidemiologie genetika MeSH
- infekční nemoci epidemiologie genetika MeSH
- interakce hostitele a patogenu genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- lokus kvantitativního znaku MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mykózy epidemiologie genetika MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- parazitární nemoci epidemiologie genetika MeSH
- pohlavní dimorfismus * MeSH
- pohlavní steroidní hormony fyziologie MeSH
- rozložení podle pohlaví MeSH
- virové nemoci epidemiologie genetika MeSH
- zánět MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- srovnávací studie MeSH
Intra-amniotic infections (IAI) are one of the reasons for preterm birth. High mobility group box 1 (HMGB1) is a nuclear protein with various physiological functions, including tissue healing. Its excessive extracellular release potentiates inflammatory reaction and can revert its action from beneficial to detrimental. We infected the amniotic fluid of a pig on the 80th day of gestation with 1 × 104 colony forming units (CFUs) of E. coli O55 for 10 h, and evaluated the appearance of HMGB1, receptor for glycation endproducts (RAGE), and Toll-like receptor (TLR) 4 in the amniotic membrane and fluid. Sham-infected amniotic fluid served as a control. The expression and release of HMGB1 were evaluated by Real-Time PCR, immunofluorescence, immunohistochemistry, and ELISA. The infection downregulated HMGB1 mRNA expression in the amniotic membrane, changed the distribution of HMGB1 protein in the amniotic membrane, and increased its level in amniotic fluid. All RAGE mRNA, protein expression in the amniotic membrane, and soluble RAGE level in the amniotic fluid were downregulated. TLR4 mRNA and protein expression and soluble TLR4 were all upregulated. HMGB1 is a potential target for therapy to suppress the exaggerated inflammatory response. This controlled expression and release can, in some cases, prevent the preterm birth of vulnerable infants. Studies on suitable animal models can contribute to the development of appropriate therapy.
- MeSH
- amnion imunologie mikrobiologie patologie MeSH
- Escherichia coli růst a vývoj patogenita MeSH
- infekce vyvolané Escherichia coli genetika imunologie mikrobiologie veterinární MeSH
- infekční komplikace v těhotenství genetika imunologie mikrobiologie veterinární MeSH
- interakce hostitele a patogenu genetika imunologie MeSH
- lidé MeSH
- messenger RNA genetika imunologie MeSH
- modely nemocí na zvířatech MeSH
- plodová voda imunologie mikrobiologie MeSH
- prasata MeSH
- předčasný porod prevence a kontrola MeSH
- protein HMGB1 genetika imunologie MeSH
- receptor pro konečné produkty pokročilé glykace genetika imunologie MeSH
- regulace genové exprese MeSH
- signální transdukce MeSH
- těhotenství MeSH
- toll-like receptor 4 genetika imunologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Receptor adenylate cyclases (RACs) on the surface of trypanosomatids are important players in the host-parasite interface. They detect still unidentified environmental signals that affect the parasites' responses to host immune challenge, coordination of social motility, and regulation of cell division. A lesser known class of oxygen-sensing adenylate cyclases (OACs) related to RACs has been lost in trypanosomes and expanded mostly in Leishmania species and related insect-dwelling trypanosomatids. In this work, we have undertaken a large-scale phylogenetic analysis of both classes of adenylate cyclases (ACs) in trypanosomatids and the free-living Bodo saltans. We observe that the expanded RAC repertoire in trypanosomatids with a two-host life cycle is not only associated with an extracellular lifestyle within the vertebrate host, but also with a complex path through the insect vector involving several life cycle stages. In Trypanosoma brucei, RACs are split into two major clades, which significantly differ in their expression profiles in the mammalian host and the insect vector. RACs of the closely related Trypanosoma congolense are intermingled within these two clades, supporting early RAC diversification. Subspecies of T. brucei that have lost the capacity to infect insects exhibit high numbers of pseudogenized RACs, suggesting many of these proteins have become redundant upon the acquisition of a single-host life cycle. OACs appear to be an innovation occurring after the expansion of RACs in trypanosomatids. Endosymbiont-harboring trypanosomatids exhibit a diversification of OACs, whereas these proteins are pseudogenized in Leishmania subgenus Viannia. This analysis sheds light on how ACs have evolved to allow diverse trypanosomatids to occupy multifarious niches and assume various lifestyles.
Non-coding RNAs (ncRNAs) are nucleotide sequences that are known to assume regulatory roles previously thought to be reserved for proteins. Their functions include the regulation of protein activity and localization and the organization of subcellular structures. Sequencing studies have now identified thousands of ncRNAs encoded within the prokaryotic and eukaryotic genomes, leading to advances in several fields including parasitology. ncRNAs play major roles in several aspects of vector-host-pathogen interactions. Arthropod vector ncRNAs are secreted through extracellular vesicles into vertebrate hosts to counteract host defense systems and ensure arthropod survival. Conversely, hosts can use specific ncRNAs as one of several strategies to overcome arthropod vector invasion. In addition, pathogens transmitted through vector saliva into vertebrate hosts also possess ncRNAs thought to contribute to their pathogenicity. Recent studies have addressed ncRNAs in vectors or vertebrate hosts, with relatively few studies investigating the role of ncRNAs derived from pathogens and their involvement in establishing infections, especially in the context of vector-borne diseases. This Review summarizes recent data focusing on pathogen-derived ncRNAs and their role in modulating the cellular responses that favor pathogen survival in the vertebrate host and the arthropod vector, as well as host ncRNAs that interact with vector-borne pathogens.
Chromoblastomykózy a feohyfomykózy jsou méně časté mykotické infekce, které jsou vyvolávány tmavě pigmentovanými houbami. Faktory virulence hrají významnou úlohu v patogenezi těchto onemocnění. Muriformní buňky jsou jedním z těchto faktorů a jsou také nejdůležitějším prvkem pro diferenciální diagnostiku chromoblastomykózy a feohyfomykózy z klinického materiálu pomocí různých technik barvení mikroskopických preparátů. Přesná identifikace původců chromoblastomykóz a feohyfomykóz je velmi důležitá z hlediska správného a včasného přístupu k antimykotické terapii, a proto je vhodné využít pro konfirmaci druhové identifikace etiologického agens sekvenaci DNA z narostlé kultury. Včasná diagnostika může být klíčová, zejména v případě invazivních forem těchto infekcí. Některé imunochemické metody mohou být při navádění diagnostika správným směrem nápomocné a detekce DNA metodou polymerázové řetězové reakce přímo z klinického materiálu se zdá být užitečná pro identifikaci původců těchto závažných a život ohrožujících infekcí.
Chromoblastomycosis and phaeohyphomycosis are less common fungal infections caused by dark-pigmented fungi. Virulence factors play an important role in the pathogenesis of these diseases. One of these factors, muriform cells, are the most important element for differential diagnosis of chromoblastomycosis and phaeohyphomycosis using clinical samples and various staining techniques. Accurate identification of pathogens causing chromoblastomycosis and phaeohyphomycosis is very important for correct and early antifungal therapy. Therefore, species identification of the etiological agent should be confirmed by sequencing of DNA from the culture. Early diagnosis may be crucial, especially in case of invasive forms of these infections. The diagnosis may be guided by some immunohistochemistry methods and DNA detection using polymerase chain reaction directly from clinical samples seems to be useful for identification of pathogens causing these severe and life-threatening infections.
- MeSH
- Ascomycota enzymologie izolace a purifikace patogenita MeSH
- barvení a značení metody MeSH
- chromoblastomykóza * mikrobiologie patologie MeSH
- faktory virulence analýza imunologie izolace a purifikace MeSH
- histologické techniky metody MeSH
- imunohistochemie metody MeSH
- interakce hostitele a patogenu genetika imunologie MeSH
- kultivační média speciální MeSH
- lidé MeSH
- phaeohyphomykóza * mikrobiologie patologie MeSH
- polymerázová řetězová reakce metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Knowledge of genomic interindividual variability could help us to explain why different manifestation of clinical severity of Covid-19 infection as well as modified pharmacogenetic relations can be expected during this pandemic condition.
- MeSH
- angiotensin konvertující enzym genetika MeSH
- angiotensin-konvertující enzym 2 MeSH
- Betacoronavirus fyziologie MeSH
- COVID-19 MeSH
- genetická predispozice k nemoci MeSH
- interakce hostitele a patogenu genetika MeSH
- koronavirové infekce genetika MeSH
- lidé MeSH
- pandemie MeSH
- SARS-CoV-2 MeSH
- virová pneumonie genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Tetherin/BST-2 is an antiviral protein that blocks the release of enveloped viral particles by linking them to the membrane of producing cells. At first, BST-2 genes were described only in humans and other mammals. Recent work identified BST-2 orthologs in nonmammalian vertebrates, including birds. Here, we identify the BST-2 sequence in domestic chicken (Gallus gallus) for the first time and demonstrate its activity against avian sarcoma and leukosis virus (ASLV). We generated a BST-2 knockout in chicken cells and showed that BST-2 is a major determinant of an interferon-induced block of ASLV release. Ectopic expression of chicken BST-2 blocks the release of ASLV in chicken cells and of human immunodeficiency virus type 1 (HIV-1) in human cells. Using metabolic labeling and pulse-chase analysis of HIV-1 Gag proteins, we verified that chicken BST-2 blocks the virus at the release stage. Furthermore, we describe BST-2 orthologs in multiple avian species from 12 avian orders. Previously, some of these species were reported to lack BST-2, highlighting the difficulty of identifying sequences of this extremely variable gene. We analyzed BST-2 genes in the avian orders Galliformes and Passeriformes and showed that they evolve under positive selection. This indicates that avian BST-2 is involved in host-virus evolutionary arms races and suggests that BST-2 antagonists exist in some avian viruses. In summary, we show that chicken BST-2 has the potential to act as a restriction factor against ASLV. Characterizing the interaction of avian BST-2 with avian viruses is important in understanding innate antiviral defenses in birds.IMPORTANCE Birds are important hosts of viruses that have the potential to cause zoonotic infections in humans. However, only a few antiviral genes (called viral restriction factors) have been described in birds, mostly because birds lack counterparts of highly studied mammalian restriction factors. Tetherin/BST-2 is a restriction factor, originally described in humans, that blocks the release of newly formed virus particles from infected cells. Recent work identified BST-2 in nonmammalian vertebrate species, including birds. Here, we report the BST-2 sequence in domestic chicken and describe its antiviral activity against a prototypical avian retrovirus, avian sarcoma and leukosis virus (ASLV). We also identify BST-2 genes in multiple avian species and show that they evolve rapidly in birds, which is an important indication of their relevance for antiviral defense. Analysis of avian BST-2 genes will shed light on defense mechanisms against avian viral pathogens.
- MeSH
- antigen stromálních buněk kostní dřeně genetika imunologie MeSH
- buněčné linie MeSH
- fibroblasty imunologie virologie MeSH
- Galliformes genetika imunologie virologie MeSH
- genové produkty gag - virus lidské imunodeficience genetika imunologie MeSH
- HEK293 buňky MeSH
- HIV-1 genetika imunologie MeSH
- interakce hostitele a patogenu genetika imunologie MeSH
- lidé MeSH
- molekulární evoluce * MeSH
- Passeriformes genetika imunologie virologie MeSH
- ptačí proteiny genetika imunologie MeSH
- ptačí sarkom genetika imunologie virologie MeSH
- regulace genové exprese MeSH
- replikace viru MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- sekvenční seřazení MeSH
- selekce (genetika) MeSH
- signální transdukce MeSH
- uvolnění viru z buňky MeSH
- viry ptačího sarkomu genetika imunologie patogenita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, N.I.H., Intramural MeSH
Bordetella pertussis, a strictly human re-emerging pathogen and the causative agent of whooping cough, exploits a broad variety of virulence factors to establish efficient infection. Here, we used RNA sequencing to analyse the changes in gene expression profiles of human THP-1 macrophages resulting from B. pertussis infection. In parallel, we attempted to determine the changes in intracellular B. pertussis-specific transcriptomic profiles resulting from interaction with macrophages. Our analysis revealed that global gene expression profiles in THP-1 macrophages are extensively rewired 6 h post-infection. Among the highly expressed genes, we identified those encoding cytokines, chemokines, and transcription regulators involved in the induction of the M1 and M2 macrophage polarization programmes. Notably, several host genes involved in the control of apoptosis and inflammation which are known to be hijacked by intracellular bacterial pathogens were overexpressed upon infection. Furthermore, in silico analyses identified large temporal changes in expression of specific gene subsets involved in signalling and metabolic pathways. Despite limited numbers of the bacterial reads, we observed reduced expression of majority of virulence factors and upregulation of several transcriptional regulators during infection suggesting that intracellular B. pertussis cells switch from virulent to avirulent phase and actively adapt to intracellular environment, respectively.
- MeSH
- Bordetella pertussis fyziologie MeSH
- buněčné linie MeSH
- genová ontologie MeSH
- genové regulační sítě MeSH
- interakce hostitele a patogenu genetika imunologie MeSH
- kultivované buňky MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- lidé MeSH
- makrofágy imunologie metabolismus mikrobiologie MeSH
- pertuse genetika imunologie virologie MeSH
- regulace genové exprese MeSH
- reprodukovatelnost výsledků MeSH
- stanovení celkové genové exprese * metody MeSH
- transkriptom * MeSH
- výpočetní biologie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Even though speciation involving multiple interacting partners, such as plants and their pollinators, has attracted much research, most studies focus on isolated phases of the process. This currently precludes an integrated understanding of the mechanisms leading to cospeciation. Here, we examine population genetic structure across six species-pairs of figs and their pollinating wasps along an elevational gradient in New Guinea. Specifically, we test three hypotheses on the genetic structure within the examined species-pairs and find that the hypothesized genetic structures represent different phases of a single continuum, from incipient cospeciation to the full formation of new species. Our results also illuminate the mechanisms governing cospeciation, namely that fig wasps tend to accumulate population genetic differences faster than their figs, which initially decouples the speciation dynamics between the two interacting partners and breaks down their one-to-one matching. This intermediate phase is followed by genetic divergence of both partners, which may eventually restore the one-to-one matching among the fully formed species. Together, these findings integrate current knowledge on the mechanisms operating during different phases of the cospeciation process. They also reveal that the increasingly reported breakdowns in one-to-one matching may be an inherent part of the cospeciation process. Mechanistic understanding of this process is needed to explain how the extraordinary diversity of species, especially in the tropics, has emerged. Knowing which breakdowns in species interactions are a natural phase of cospeciation and which may endanger further generation of diversity seems critical in a constantly changing world.
