RESUMEN
Pacific Island countries have experienced periodic dengue, chikungunya and Zika outbreaks for decades. The prevention and control of these mosquito-borne diseases rely heavily on control of Aedes aegypti mosquitoes, which in most settings are the primary vector. Introgression of the intracellular bacterium Wolbachia pipientis (wMel strain) into Ae. aegypti populations reduces their vector competence and consequently lowers dengue incidence in the human population. Here we describe successful area-wide deployments of wMel-infected Ae. aegypti in Suva, Lautoka, Nadi (Fiji), Port Vila (Vanuatu) and South Tarawa (Kiribati). With community support, weekly releases of wMel-infected Ae. aegypti mosquitoes for between 2 to 5 months resulted in wMel introgression in nearly all locations. Long term monitoring confirmed a high, self-sustaining prevalence of wMel infecting mosquitoes in almost all deployment areas. Measurement of public health outcomes were disrupted by the Covid19 pandemic but are expected to emerge in the coming years.
Asunto(s)
Aedes , Virus del Dengue , Dengue , Wolbachia , Infección por el Virus Zika , Virus Zika , Animales , Humanos , Aedes/genética , Aedes/microbiología , Mosquitos Vectores/genética , Mosquitos Vectores/microbiología , Wolbachia/genética , Fiji/epidemiología , VanuatuRESUMEN
BACKGROUND: The wMel strain of Wolbachia has been successfully introduced into Aedes aegypti mosquitoes and has been shown to reduce the transmission of dengue and other Aedes-borne viruses. Here we report the entomological results from phased, large-scale releases of Wolbachia infected Ae. aegypti mosquitoes throughout three contiguous cities located in the Aburrá Valley, Colombia. METHODOLOGY/PRINCIPAL FINDINGS: Local wMel Wolbachia-infected Ae. aegypti mosquitoes were generated and then released in an initial release pilot area in 2015-2016, which resulted in the establishment of Wolbachia in the local mosquito populations. Subsequent large-scale releases, mainly involving vehicle-based releases of adult mosquitoes along publicly accessible roads and streets, were undertaken across 29 comunas throughout Bello, Medellín and Itagüí Colombia between 2017-2022. In 9 comunas these were supplemented by egg releases that were undertaken by staff or community members. By the most recent monitoring, Wolbachia was found to be stable and established at consistent levels in local mosquito populations (>60% prevalence) in the majority (67%) of areas. CONCLUSION: These results, from the largest contiguous releases of wMel Wolbachia mosquitoes to date, highlight the operational feasibility of implementing the method in large urban settings. Based on results from previous studies, we expect that Wolbachia establishment will be sustained long term. Ongoing monitoring will confirm Wolbachia persistence in local mosquito populations and track its establishment in the remaining areas.
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Aedes , Wolbachia , Animales , Humanos , Ciudades , Colombia , Ambiente , Mosquitos VectoresRESUMEN
BACKGROUND: Patients with glioblastomas have a dismal prognosis, and there is no circulating predictive or prognostic biomarker. Circulating progastrin, hPG80, is a tumor-promoting peptide present in the blood of patients with various cancers that has been shown to have prognostic value. We evaluated the prognostic value of plasma hPG80 in patients with isocitrate dehydrogenase-wild type glioblastoma after surgery. PATIENTS AND METHODS: A multicentric retrospective study in glioblastoma patients treated with standard radio-chemotherapy was conducted. The hPG80 levels were measured in plasma EDTA samples collected after surgery with an ELISA DxPG80.lab kit (Biodena Care, Montpellier, France), which has a detection threshold of 1.2 pM. The relationship between post-operative hPG80 plasma levels, in combination with other known prognostic factors, and patients' progression-free survival (PFS) and overall survival (OS) was evaluated. RESULTS: Sixty-nine patients were assessable. Plasma samples were collected after tumor biopsy (B), partial resection (PR), and complete resection (CR) for 22, 25, and 22 patients, respectively. At a median concentration of 5.37 pM (interquartile range 0.00-13.90 pM), hPG80 was detected in 48 (70%) patients (hPG80+). CR was associated with significant lower values of hPG80 levels: the median value was 0.7 versus 9.1 pM for PR (P = 0.02) and 8.3 pM for B (P = 0.004). The hPG80 detection rate was also significantly lower: 50% (CR) versus 72% (PR) versus 86% (B) (P = 0.005). The median follow-up was 39 months [22.4 months-not reached]. hPG80 post-operative detection was associated with numerically shorter PFS (6.4 versus 9.4 months, P = 0.13) and OS (14.5 versus 20.9 months, P = 0.11). In multivariate analysis, hPG80 was a prognostic factor for OS (P = 0.034). CONCLUSIONS: Circulating hPG80 could serve as a new prognostic biomarker after surgery in patients with glioblastoma treated with radio-chemotherapy.
Asunto(s)
Glioblastoma , Humanos , Glioblastoma/cirugía , Glioblastoma/tratamiento farmacológico , Estudios Retrospectivos , Pronóstico , BiomarcadoresRESUMEN
BACKGROUND: Introgression of the bacterial endosymbiont Wolbachia into Aedes aegypti populations is a biocontrol approach being used to reduce arbovirus transmission. This requires mass release of Wolbachia-infected mosquitoes. While releases have been conducted using a variety of techniques, egg releases, using water-soluble capsules containing mosquito eggs and larval food, offer an attractive method due to its potential to reduce onsite resource requirements. However, optimisation of this approach is required to ensure there is no detrimental impact on mosquito fitness and to promote successful Wolbachia introgression. METHODS: We determined the impact of storage time and temperature on wild-type (WT) and Wolbachia-infected (wMel or wAlbB strains) Ae. aegypti eggs. Eggs were stored inside capsules over 8 weeks at 18 °C or 22 °C and hatch rate, emergence rate and Wolbachia density were determined. We next examined egg quality and Wolbachia density after exposing eggs to 4-40 °C to determine how eggs may be impacted if exposed to extreme temperatures during shipment. RESULTS: Encapsulating eggs for 8 weeks did not negatively impact egg viability or resulting adult emergence and Wolbachia density compared to controls. When eggs were exposed to temperatures within 4-36 °C for 48 h, their viability and resulting adult Wolbachia density were maintained; however, both were significantly reduced when exposed to 40 °C. CONCLUSIONS: We describe the time and temperature limits for maintaining viability of Wolbachia-infected Ae. aegypti eggs when encapsulated or exposed to extreme temperatures. These findings could improve the efficiency of mass releases by providing transport and storage constraints to ensure only high-quality material is utilised during field releases.
Asunto(s)
Aedes , Wolbachia , Animales , Temperatura , Mosquitos Vectores , HuevosRESUMEN
BACKGROUND: The anatomical pathology autopsy serves several purposes, notably as a quality management tool for evaluation of accuracy in clinical diagnosis. Despite its value, for various reasons there has been an international decline in autopsies conducted. In the modern medical era, with all its advances in technology, diagnostic techniques and interventions, there is still a high discrepancy between clinical diagnoses and postmortem findings. OBJECTIVES: To establish the discrepancies between clinical diagnoses and postmortem findings in anatomical pathology autopsies. METHODS: A retrospective, descriptive study was conducted over the 4-year-period 2014 - 2017. The clinical diagnoses and postmortem findings of cases referred to the Department of Anatomical Pathology at the University of Pretoria, South Africa, were evaluated and compared using the modified Goldman criteria. RESULTS: A total of 288 cases qualified for the study and were evaluated. The gender distribution was 155 (53.8%) male and 133 (48.2%) female, with the majority of cases in the age group 19 - 60 years (mean 36.4). The majority of the cases were referred by internal medicine, followed by paediatrics. The most common cause of death in major missed diagnoses was pulmonary conditions. Of the cases, 115 (39.3%) had a major discrepancy and 62 (21.5%) a minor discrepancy. CONCLUSION: This study showed that there is still a high discrepancy between clinical diagnoses and postmortem findings, similar to studies conducted globally. The current COVID-19 pandemic may be a driver for revival of the anatomical pathology autopsy, and future studies are recommended to evaluate whether the decline can be reversed.
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COVID-19 , Pandemias , Femenino , Masculino , Humanos , Niño , Adulto Joven , Adulto , Persona de Mediana Edad , Autopsia , Sudáfrica , Estudios RetrospectivosRESUMEN
The Wolbachia insect control method, employed by the World Mosquito Program (WMP), relies on introgressing Wolbachia through target Aedes aegypti populations to reduce the incidence of dengue. Since 2010, the WMP has been producing Wolbachia-infected mosquitoes at numerous sites across the globe for release in 11 countries. As the technology has matured, greater focus has been placed on mosquito production at larger central facilities for transport to remote release sites, both domestically and internationally. Of particular note is the production of Wolbachia-infected mosquitoes at the WMP's Australian production facility for successful international deployments in Fiji, Vanuatu, Kiribati and Sri Lanka. This requires careful management of both production and supply-chain processes to ensure that the quality of the mosquito eggs, specifically the hatch rate and Wolbachia infection rate, is maintained. To ensure the cost-effectiveness and scalability of the Wolbachia method, these processes will be further refined to facilitate deployment from large centralised production facilities.
La méthode de contrôle des insectes mise en oeuvre par le World Mosquito Program (WMP) recourt à la bactérie Wolbachia et repose sur l'introgression de cette dernière par le biais des populations cibles d'Aedes aegypti dans le but de réduire l'incidence de la dengue. Depuis 2010, le WMP produit des moustiques infectés par Wolbachia à partir de nombreux sites répartis dans le monde entier en vue de leur lâcher dans 11 pays. Cette technologie s'étant bien développée, l'accent est désormais mis sur la production de moustiques dans des établissements centralisés de plus grande envergure afin de les expédier vers des sites de lâcher éloignés, tant sur le territoire national qu'à l'échelle internationale. Il importe de souligner la production de moustiques infectés par Wolbachia conduite par le WMP sur son site australien et leur déploiement international couronné de succès aux Fidji, au Vanuatu, à Kiribati et au Sri Lanka. Cela nécessite une gestion rigoureuse des procédures aussi bien lors de la production que tout au long de la chaîne d'approvisionnement afin de veiller au maintien de la qualité des oeufs de moustiques et plus spécifiquement du taux d'éclosion et du taux d'infection par Wolbachia. Afin d'assurer la rentabilité et l'évolutivité de la méthode basée sur Wolbachia, ces procédures seront encore affinées afin de faciliter le déploiement à partir de sites de production à grande échelle centralisés.
El método de control de insectos con Wolbachia que emplea el World Mosquito Program (WMP) reposa en la introgresión de Wolbachia a través de poblaciones de Aedes aegypti para reducir la incidencia del dengue. Desde 2010, el WMP viene generando mosquitos infectados por Wolbachia en numerosas instalaciones repartidas por todo el globo, mosquitos que después son liberados en 11 países. A medida que la tecnología ha ido madurando, la tendencia ha sido cada vez más la de concentrar la producción de mosquitos en grandes instalaciones centrales y desde allí enviarlos a los remotos lugares de suelta, ya estén en el mismo país o en otros países. Especialmente destacable es la producción de mosquitos infectados por Wolbachia en las instalaciones que el WMP tiene en Australia, utilizadas con éxito como centro de operaciones para aplicar el método en otros países como Fiji, Vanuatu, Kiribati y Sri Lanka. Ello exige una cuidadosa gestión de los procesos tanto de producción como de la cadena de suministro, que garantice un nivel constante de calidad de los huevos de mosquito, y más concretamente de las tasas de eclosión y de infección por Wolbachia. A fin de asegurar que el método ofrezca una buena relación costo-eficacia y sea reproducible a mayor escala, esos procesos serán perfeccionados para facilitar el despliegue de los insectos a partir de grandes instalaciones de producción centralizada.
Asunto(s)
Aedes , Dengue , Wolbachia , Animales , Australia , Dengue/epidemiología , Dengue/veterinaria , Mosquitos Vectores , Óvulo , Control Biológico de VectoresRESUMEN
Release and subsequent establishment of Wolbachia-infected Aedes aegypti in native mosquito populations has successfully reduced mosquito-borne disease incidence. While this is promising, further development is required to ensure that this method is scalable and sustainable. Egg release is a beneficial technique that requires reduced onsite resources and increases community acceptance; however, its incidental ecological impacts must be considered to ensure sustainability. In this study, we tested a more environmentally friendly mosquito rearing and release approach through the encapsulation of diet and egg mixtures and the subsequent utilization of waste containers to hatch and release mosquitoes. An ecologically friendly diet mix was specifically developed and tested for use in capsules, and we demonstrated that using either cricket or black soldier fly meal as a substitute for beef liver powder had no adverse effects on fitness or Wolbachia density. We further encapsulated both the egg and diet mixes and demonstrated no loss in viability. To address the potential of increased waste generation through disposable mosquito release containers, we tested reusing commonly found waste containers (aluminum and tin cans, PET, and glass bottles) as an alternative, conducting a case study in Kiribati to assess the concept's cultural, political, and economic applicability. Our results showed that mosquito emergence and fitness was maintained with a variety of containers, including when tested in the field, compared to control containers, and that there are opportunities to implement this method in the Pacific Islands in a way that is culturally considerate and cost-effective.
RESUMEN
The artificial introduction of the endosymbiotic bacterium, Wolbachia pipientis, into Aedes (Ae.) aegypti mosquitoes reduces the ability of mosquitoes to transmit human pathogenic viruses and is now being developed as a biocontrol tool. Successful introgression of Wolbachia-carrying Ae. aegypti into native mosquito populations at field sites in Australia, Indonesia and Malaysia has been associated with reduced disease prevalence in the treated community. In separate field programs, Wolbachia is also being used as a mosquito population suppression tool, where the release of male only Wolbachia-infected Ae. aegypti prevents the native mosquito population from producing viable eggs, subsequently suppressing the wild population. While these technologies show great promise, they require mass rearing of mosquitoes for implementation on a scale that has not previously been done. In addition, Wolbachia induces some negative fitness effects on Ae. aegypti. While these fitness effects differ depending on the Wolbachia strain present, one of the most consistent and significant impacts is the shortened longevity and viability of eggs. This review examines the body of evidence behind Wolbachia's negative effect on eggs, assesses nutritional parasitism as a key cause and considers how these impacts could be overcome to achieve efficient large-scale rearing of these mosquitoes.
RESUMEN
An efficient method that assists in the re-parametrization of structurally unidentifiable models is introduced. It significantly reduces computational demand by combining numerical and symbolic identifiability calculations. This hybrid approach facilitates the re-parametrization of large unidentifiable ordinary differential equation models, including models where state transformations are required. A model is first assessed numerically, to discover potential structurally unidentifiable parameters. We then use symbolic calculations to confirm the numerical results, after which we describe the algebraic relationships between the unidentifiable parameters. Finally, the unidentifiable parameters are substituted with new parameters and simplification ensures that all the unidentifiable parameters are eliminated from the original model structure. The novelty of this method is its utilisation of numerical results, which notably reduces the number of symbolic calculations required. We illustrate our procedure and the detailed re-parametrization process in 5 examples: (1) an immunological model, (2) a microbial growth model, (3) a lung cancer model, (4) a JAK/STAT model, and (5) a small linear model with a non-scalable re-parametrization.
Asunto(s)
Investigación Biomédica/métodos , Interpretación Estadística de Datos , Modelos Biológicos , Animales , HumanosRESUMEN
The process of inferring parameter values from experimental data can be a cumbersome task. In addition, the collection of experimental data can be time consuming and costly. This paper covers both these issues by addressing the following question: "Which experimental outputs should be measured to ensure that unique model parameters can be calculated?". Stated formally, we examine the topic of minimal output sets that guarantee a model's structural identifiability. To that end, we introduce an algorithm that guides a researcher as to which model outputs to measure. Our algorithm consists of an iterative structural identifiability analysis and can determine multiple minimal output sets of a model. This choice in different output sets offers researchers flexibility during experimental design. Our method can determine minimal output sets of large differential equation models within short computational times.
Asunto(s)
Algoritmos , Modelos TeóricosRESUMEN
Insect-symbiont interactions are known to play key roles in host functions and fitness. The common insect endosymbiont Wolbachia can reduce the ability of several human pathogens, including arboviruses and the malaria parasite, to replicate in insect hosts. Wolbachia does not naturally infect Aedes aegypti, the primary vector of dengue virus, but transinfected Ae. aegypti have antidengue virus properties and are currently being trialled as a dengue biocontrol strategy. Here, we assess the impact of Wolbachia infection of Ae. aegypti on the microbiome of wild mosquito populations (adults and larvae) collected from release sites in Cairns, Australia, by profiling the 16S rRNA gene using next-generation sequencing. Our data indicate that Wolbachia reduces the relative abundance of a large proportion of bacterial taxa in Ae. aegypti adults, that is in accordance with the known pathogen-blocking effects of Wolbachia on a variety of bacteria and viruses. In adults, several of the most abundant bacterial genera were found to undergo significant shifts in relative abundance. However, the genera showing the greatest changes in relative abundance in Wolbachia-infected adults represented a low proportion of the total microbiome. In addition, there was little effect of Wolbachia infection on the relative abundance of bacterial taxa in larvae, or on species diversity (accounting for species richness and evenness together) detected in adults or larvae. These results offer insight into the effects of Wolbachia on the Ae. aegypti microbiome in a native setting, an important consideration for field releases of Wolbachia into the population.
Asunto(s)
Aedes/microbiología , Wolbachia/fisiología , Animales , Australia , Biodiversidad , Femenino , Genes Bacterianos , Secuenciación de Nucleótidos de Alto Rendimiento , Larva/microbiología , Microbiota/genética , Filogenia , ARN Ribosómico 16S/genética , Wolbachia/clasificaciónRESUMEN
For a reconstruction of state and parameter values in a dynamic system model, first the question whether these values can be uniquely determined from the data must be answered. This structural model property is known as observability or, in case of parameter calibration only, identifiability. Testing a given model for observability is a well studied problem in the systems and control sciences. However, it is increasingly difficult, if not impossible, to address this property for large size models that, nowadays, are frequently used. We demonstrate the application of a recently developed algorithm that overcomes this problem and is remarkably efficient. As an illustration we show how an observability analysis for a Chinese Hamster Ovary Cell model (34 states, 117 parameters), a JAKSTAT signalling model (31 states, 51 parameters), and a MAP Kinase model (100 states, 88 parameters) can be established in a very short time.
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Algoritmos , Animales , Células CHO , Cricetinae , Cricetulus , Modelos Biológicos , Dinámicas no Lineales , Transducción de Señal/fisiologíaRESUMEN
Wolbachia pipientis is an insect endosymbiont known to limit the replication of viruses including dengue and Zika in their primary mosquito vector, Aedes aegypti. Wolbachia is being released into mosquito populations globally in a bid to control the diseases caused by these viruses. It is theorized that Wolbachia's priming of the insect immune system may confer protection against subsequent viral infection. Other hypotheses posit a role for competition between Wolbachia and viruses for host cellular resources. Using an A. aegypti cell line infected with Wolbachia, we tested the effects of targeting siRNAs against the major innate immune pathways on dengue virus loads. We show that while Wolbachia infection induces genes in the Toll, JAK/STAT and RNAi pathways, only reduced expression of RNAi leads to a rebound of dengue virus loads in Wolbachia-infected cells. The magnitude of the effect explained less than 10% of the total DENV load, demonstrating that blocking must be dependent on other factors in addition to the expression of RNAi. The findings bode well for the long-term stability of blocking given that immunity gene expression would likely be highly plastic and susceptible to rapid evolution.
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Virus del Dengue/inmunología , Mosquitos Vectores/inmunología , Interferencia de ARN/inmunología , Wolbachia/inmunología , Aedes/inmunología , Aedes/microbiología , Aedes/virología , Animales , Antibiosis/genética , Antibiosis/inmunología , Línea Celular , Virus del Dengue/genética , Virus del Dengue/fisiología , Expresión Génica/inmunología , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Mosquitos Vectores/microbiología , Mosquitos Vectores/virología , Replicación Viral/genética , Replicación Viral/inmunología , Wolbachia/genética , Wolbachia/fisiologíaRESUMEN
Wolbachia pipientis is an endosymbiotic bacterium estimated to chronically infect between 40-75% of all arthropod species. Aedes aegypti, the principle mosquito vector of dengue virus (DENV), is not a natural host of Wolbachia. The transinfection of Wolbachia strains such as wAlbB, wMel and wMelPop-CLA into Ae. aegypti has been shown to significantly reduce the vector competence of this mosquito for a range of human pathogens in the laboratory. This has led to wMel-transinfected Ae. aegypti currently being released in five countries to evaluate its effectiveness to control dengue disease in human populations. Here we describe the generation of a superinfected Ae. aegypti mosquito line simultaneously infected with two avirulent Wolbachia strains, wMel and wAlbB. The line carries a high overall Wolbachia density and tissue localisation of the individual strains is very similar to each respective single infected parental line. The superinfected line induces unidirectional cytoplasmic incompatibility (CI) when crossed to each single infected parental line, suggesting that the superinfection would have the capacity to replace either of the single constituent infections already present in a mosquito population. No significant differences in fitness parameters were observed between the superinfected line and the parental lines under the experimental conditions tested. Finally, the superinfected line blocks DENV replication more efficiently than the single wMel strain when challenged with blood meals from viremic dengue patients. These results suggest that the deployment of superinfections could be used to replace single infections and may represent an effective strategy to help manage potential resistance by DENV to field deployments of single infected strains.
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Aedes/microbiología , Insectos Vectores/inmunología , Control Biológico de Vectores , Infecciones por Rickettsiaceae/microbiología , Sobreinfección/microbiología , Wolbachia , Animales , Dengue/virología , Virus del Dengue , Femenino , Humanos , Control Biológico de Vectores/métodos , Saliva/microbiología , Replicación ViralRESUMEN
Accumulating evidence suggests that changes of the protein synthesis machinery alter translation of specific mRNAs and participate in malignant transformation. Here we show that protein kinase C α (PKCα) interacts with TRM61, the catalytic subunit of the TRM6/61 tRNA methyltransferase. The TRM6/61 complex is known to methylate the adenosine 58 of the initiator methionine tRNA (tRNAi(Met)), a nuclear post-transcriptional modification associated with the stabilization of this crucial component of the translation-initiation process. Depletion of TRM6/61 reduced proliferation and increased death of C6 glioma cells, effects that can be partially rescued by overexpression of tRNAi(Met). In contrast, elevated TRM6/61 expression regulated the translation of a subset of mRNAs encoding proteins involved in the tumorigenic process and increased the ability of C6 cells to form colonies in soft agar or spheres when grown in suspension. In TRM6/61/tRNAi(Met)-overexpressing cells, PKCα overexpression decreased tRNAi(Met) expression and both colony- and sphere-forming potentials. A concomitant increase in TRM6/TRM61 mRNA and tRNAi(Met) expression with decreased expression of PKCα mRNA was detected in highly aggressive glioblastoma multiforme as compared with Grade II/III glioblastomas, highlighting the clinical relevance of our findings. Altogether, we suggest that PKCα tightly controls TRM6/61 activity to prevent translation deregulation that would favor neoplastic development.
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Biomarcadores de Tumor/biosíntesis , Glioblastoma/genética , Proteína Quinasa C-alfa/genética , ARNt Metiltransferasas/biosíntesis , Apoptosis/genética , Biomarcadores de Tumor/genética , Carcinogénesis/genética , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/patología , Humanos , Metionina/genética , Proteína Quinasa C-alfa/biosíntesis , ARN de Transferencia/genética , ARNt Metiltransferasas/genéticaRESUMEN
IFN-antagonist function is a major determinant of pathogenicity and cross-species infection by viruses, but remains poorly defined for many potentially zoonotic viruses resident in animal species. The paramyxovirus family contains several zoonotic viruses, including highly pathogenic viruses such as Nipah virus and Hendra virus, and an increasing number of largely uncharacterized animal viruses. Here, we report the characterization of IFN antagonism by the rodent viruses J virus (JPV) and Beilong virus (BeiPV) of the proposed genus Jeilongvirus of the paramyxoviruses. Infection of cells by JPV and BeiPV was found to inhibit IFN-activated nuclear translocation of signal transducer and activator of transcription 1 (STAT1). However, in contrast to most other paramyxoviruses, the JPV and BeiPV V proteins did not interact with or inhibit signalling by STAT1 or STAT2, suggesting that JPV/BeiPV use an atypical V protein-independent strategy to target STATs, consistent with their inclusion in a separate genus. Nevertheless, the V proteins of both viruses interacted with melanoma differentiation-associated protein 5 (MDA5) and robustly inhibited MDA5-dependent activation of the IFN-ß promoter. This supports a growing body of evidence that MDA5 is a universal target of paramyxovirus V proteins, such that the V-MDA5 interaction represents a potential target for broad-spectrum antiviral approaches.
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Evasión Inmune , Infecciones por Paramyxoviridae/inmunología , Paramyxovirinae/inmunología , Proteínas Virales/inmunología , Animales , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/inmunología , Células HEK293 , Humanos , Helicasa Inducida por Interferón IFIH1 , Interferón-alfa/genética , Interferón-alfa/inmunología , Infecciones por Paramyxoviridae/genética , Infecciones por Paramyxoviridae/virología , Paramyxovirinae/clasificación , Paramyxovirinae/genética , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/inmunología , Factor de Transcripción STAT2/genética , Factor de Transcripción STAT2/inmunología , Transducción de Señal , Proteínas Virales/genéticaRESUMEN
UNLABELLED: Wongabel virus (WONV) is an arthropod-borne rhabdovirus that infects birds. It is one of the growing array of rhabdoviruses with complex genomes that encode multiple accessory proteins of unknown function. In addition to the five canonical rhabdovirus structural protein genes (N, P, M, G, and L), the 13.2-kb negative-sense single-stranded RNA (ssRNA) WONV genome contains five uncharacterized accessory genes, one overlapping the N gene (Nx or U4), three located between the P and M genes (U1 to U3), and a fifth one overlapping the G gene (Gx or U5). Here we show that WONV U3 is expressed during infection in insect and mammalian cells and is required for efficient viral replication. A yeast two-hybrid screen against a mosquito cell cDNA library identified that WONV U3 interacts with the 83-amino-acid (aa) C-terminal domain of SNF5, a component of the SWI/SNF chromatin remodeling complex. The interaction was confirmed by affinity chromatography, and nuclear colocalization was established by confocal microscopy. Gene expression studies showed that SNF5 transcripts are upregulated during infection of mosquito cells with WONV, as well as West Nile virus (Flaviviridae) and bovine ephemeral fever virus (Rhabdoviridae), and that SNF5 knockdown results in increased WONV replication. WONV U3 also inhibits SNF5-regulated expression of the cytokine gene CSF1. The data suggest that WONV U3 targets the SWI/SNF complex to block the host response to infection. IMPORTANCE: The rhabdoviruses comprise a large family of RNA viruses infecting plants, vertebrates, and invertebrates. In addition to the major structural proteins (N, P, M, G, and L), many rhabdoviruses encode a diverse array of accessory proteins of largely unknown function. Understanding the role of these proteins may reveal much about host-pathogen interactions in infected cells. Here we examine accessory protein U3 of Wongabel virus, an arthropod-borne rhabdovirus that infects birds. We show that U3 enters the nucleus and interacts with SNF5, a component of the chromatin remodeling complex that is upregulated in response to infection and restricts viral replication. We also show that U3 inhibits SNF5-regulated expression of the cytokine colony-stimulating factor 1 (CSF1), suggesting that it targets the chromatin remodeling complex to block the host response to infection. This study appears to provide the first evidence of a virus targeting SNF5 to inhibit host gene expression.
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Ensamble y Desensamble de Cromatina , Proteínas Cromosómicas no Histona/metabolismo , Interacciones Huésped-Patógeno , Rhabdoviridae/inmunología , Rhabdoviridae/fisiología , Factores de Transcripción/metabolismo , Proteínas Virales/metabolismo , Animales , Línea Celular , Núcleo Celular/química , Cromatografía de Afinidad , Insectos , Mamíferos , Microscopía Confocal , Técnicas del Sistema de Dos HíbridosRESUMEN
We studied the recall and perceptions of transfused patients at a single centre. Fifty-three patients were included. In 11 (20.8%) cases, no written informed consent document could be traced. Four patients who had informed consent documents in their records had no recollection of the consent process. Approximately 11% of patients stated that the consent process was performed using unfamiliar terms. When compared to Caucasian and mixed race respondents, more African respondents (83%) would have preferred the presence of a family member (p < 0.01). Although not all the patients experienced the informed consent positively, it did not impact on their perception of the blood transfusion itself.
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Población Negra , Transfusión Sanguínea , Formularios de Consentimiento , Participación del Paciente , Encuestas y Cuestionarios , Población Blanca , Adulto , Estudios Transversales , Femenino , Hospitales Universitarios , Humanos , Masculino , Persona de Mediana Edad , SudáfricaRESUMEN
In prokaryotes, small noncoding RNAs (snRNAs) of 50-500 nt are produced that are important in bacterial virulence and response to environmental stimuli. Here, we identified and characterized snRNAs from the endosymbiotic bacteria, Wolbachia, which are widespread in invertebrates and cause reproductive manipulations. Most importantly, some strains of Wolbachia inhibit replication of several vector-borne pathogens in insects. We demonstrate that two abundant snRNAs, WsnRNA-46 and WsnRNA-49, are expressed in Wolbachia from noncoding RNA transcripts that contain precursors with stem-loop structures. WsnRNAs were detected in Aedes aegypti mosquitoes infected with the wMelPop-CLA strain of Wolbachia and in Drosophila melanogaster and Drosophila simulans infected with wMelPop and wAu strains, respectively, indicating that the WsnRNAs are conserved across species and strains. In addition, we show that the WsnRNAs may potentially regulate host genes and Wolbachia genes. Our findings provide evidence for the production of functional snRNAs by Wolbachia that play roles in cross-kingdom communication between the endosymbiont and the host.
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Aedes/microbiología , ARN Bacteriano/metabolismo , ARN Pequeño no Traducido/metabolismo , Wolbachia/metabolismo , Animales , Drosophila melanogaster , ARN Bacteriano/genética , ARN Pequeño no Traducido/genética , Wolbachia/genéticaRESUMEN
Bovine ephemeral fever virus (BEFV) is an arthropod-borne rhabdovirus that is classified as the type species of the genus Ephemerovirus. In addition to the five canonical rhabdovirus structural proteins (N, P, M, G, and L), the large and complex BEFV genome contains several open reading frames (ORFs) between the G and L genes (α1, α2/α3, ß, and γ) encoding proteins of unknown function. We show that the 10.5-kDa BEFV α1 protein is expressed in infected cells and, consistent with previous predictions based on its structure, has the properties of a viroporin. Expression of a BEFV α1-maltose binding protein (MBP) fusion protein in Escherichia coli was observed to inhibit cell growth and increase membrane permeability to hygromycin B. Increased membrane permeability was also observed in BEFV-infected mammalian cells (but not cells infected with an α1-deficient BEFV strain) and in cells expressing a BEFV α1-green fluorescent protein (GFP) fusion protein, which was shown by confocal microscopy to localize to the Golgi complex. Furthermore, the predicted C-terminal cytoplasmic domain of α1, which contains a strong nuclear localization signal (NLS), was translocated to the nucleus when expressed independently, and in an affinity chromatography assay employing a GFP trap, the full-length α1 was observed to interact specifically with importin ß1 and importin 7 but not with importin α3. These data suggest that, in addition to its function as a viroporin, BEFV α1 may modulate components of nuclear trafficking pathways, but the specific role thereof remains unclear. Although rhabdovirus accessory genes occur commonly among arthropod-borne rhabdoviruses, little is known of their functions. Here, we demonstrate that the BEFV α1 ORF encodes a protein which has the structural and functional characteristics of a viroporin. We show that α1 localizes in the Golgi complex and increases cellular permeability. We also show that BEFV α1 binds importin ß1 and importin 7, suggesting that it may have a yet unknown role in modulating nuclear trafficking. This is the first functional analysis of an ephemerovirus accessory protein and of a rhabdovirus viroporin.