Search results for "viruse"
showing 10 items of 1185 documents
Desarrollo y aplicación experimental de vectores virales basados en genomas de coronavirus para prevenir infecciones por rotavirus.
2009
Las infecciones por rotavirus son la causa más importante de gastroenteritis en niños menores de cinco años de edad. Se calcula que provocan unas 600.000 muertes anuales, principalmente en los países en vías de desarrollo. Una de las estrategias más prometedoras de desarrollo de nuevas vacunas consiste en el uso de virus recombinantes. Entre los sistemas virales de expresión de proteínas recombinantes más interesantes se encuentran los coronavirus. En este trabajo se aborda la producción de vectores virales basados en genomas del coronavirus TGEV (virus de la gastroenteritis porcina transmisible) para aplicarlos como vacunas experimentales de las infecciones por rotavirus. Para ello se han …
Development of functionalized SYBR green II related cyanine dyes for viral RNA detection
2020
Fluorescent probes for sensing nucleic acids have found widespread use in the field of cell and molecular biology. However, probes combined with potential for post-synthetic conjugation, e.g. for intra-endosomal measurements of RNA, are unavailable. Herein we developed cyanine dyes that can be conjugated to viral capsid or other targets. First, we solved the crystal structure of SYBR Green II. The structural elucidation of this commonly used RNA probe provided the basis for synthesizing similar molecules with much desired function for post-synthetic conjugation. To address this need, cyanine dyes were prepared using an alternative synthesis protocol. All studied compounds showed considerabl…
Experimental evolution of an RNA virus in cells with innate immunity defects
2015
Experimental evolution studies have shown that RNA viruses respond rapidly to directional selection and thus can adapt efficiently to changes in host cell tropism, antiviral drugs, or other imposed selective pressures. However, the evolution of RNA viruses under relaxed selection has been less extensively explored. Here, we evolved vesicular stomatitis virus in mouse embryonic fibroblasts knocked-out for PKR, a protein with a central role in antiviral innate immunity. Vesicular stomatitis virus adapted to PKR-negative mouse embryonic fibroblasts in a gene-specific manner, since the evolved viruses exhibited little or no fitness improvement in PKR-positive cells. Full-length sequencing revea…
Evidence for Positive Selection in the Capsid Protein-Coding Region of the Foot-and-Mouth Disease Virus (FMDV) Subjected to Experimental Passage Regi…
2001
We present sequence data from two genomic regions of foot-and-mouth disease virus (FMDV) subjected to several experimental passage regimens. Maximum-likelihood estimates of the nonsynonymous-to-synonymous rate ratio parameter (dN/dS) suggested the action of positive selection on some antigenic sites of the FMDV capsid during some experimental passages. These antigenic sites showed an accumulation of convergent amino acid replacements during massive serial cytolytic passages and also in persistent infections of FMDV in cell culture. This accumulation was most significant at the antigenic site A (the G-H loop of capsid VP1), which includes an Arg-Gly-Asp (RGD) cellular recognition motif. Our …
Antibacterial Efficiency of Surface-Immobilized Flavobacterium-Infecting Bacteriophage
2019
Control of bacterial diseases by bacteriophages (phages) is gaining more interest due to increasing antibiotic resistance. This has led to technologies to attach phages on surfaces to form a biomaterial that can functionally display phages that interact with bacteria, to carry out successful infection cycles. Such a material could be applied in many environments, where the target pathogens are expected. Although this approach has been applied successfully in a few studies already, the basis of the antibacterial effect by the immobilized phages is unclear, and the interpretation of the results depends on the study. Here, we studied the phage attachment density, their detachment rate and infe…
The effect of a temperature-sensitive prophage on the evolution of virulence in an opportunistic bacterial pathogen.
2022
https://doi.org/10.1111/mec.16638 Abstract Viruses are key actors of ecosystems and have major impacts on global biogeochemical cycles. Prophages deserve particular attention as they are ubiquitous in bacterial genomes and can enter a lytic cycle when triggered by environmental conditions. We explored how temperature affects the interactions between prophages and other biological levels by using an opportunistic pathogen, the bacterium Serratia marcescens, that harbours several prophages and that had undergone an evolution experiment under several temperature regimes. We found that the release of one of the prophages was temperature-sensitive and malleable to evolutionary changes. We furthe…
Pathogenesis and autoimmunity initiated by a viral protein-induced apoptotic bodies
2016
Ihmisen parvovirus B19 (B19) on laajalle levinnyt, yleinen virus, joka aiheuttaa lapsissa parvorokkoa (viides tauti). Aikuisille B19 aiheuttaa erinäisiä sairauksia, muun muassa nivelkipuja ja – tulehdusta, anemiaa, sekä raskaana oleville sikiöpöhöä. Lisäksi B19 infektio saattaa johtaa autoimmuunisairauksiin, kuten punahukkaan (systemic lupus erythematosus, SLE), nivelreumaan ja sydänlihastulehdukseen. Toisaalta infektio voi olla myös täysin oireeton. Mekanismit, jotka johtavat B19 tartunnasta autoimmuunisairauteen, ovat vielä tuntemattomia. Kuitenkin tiedetään, että B19:n ei-rakenteellinen proteiini NS1 on soluille tuhoisa ja aiheuttaa niiden kuoleman (apoptoosin) muodostaen solunjäännösten…
Questing abundance of adult taiga ticks Ixodes persulcatus and their Borrelia prevalence at the north-western part of their distribution
2020
Background Because ixodid ticks are vectors of zoonotic pathogens, including Borrelia, information of their abundance, seasonal variation in questing behaviour and pathogen prevalence is important for human health. As ticks are invading new areas northwards, information from these new areas are needed. Taiga tick (Ixodes persulcatus) populations have been recently found at Bothnian Bay, Finland. We assessed seasonal variation in questing abundance of ticks and their pathogen prevalence in coastal deciduous forests near the city of Oulu (latitudes 64–65°) in 2019. Methods We sampled ticks from May until September by cloth dragging 100 meters once a month at eight study sites. We calculated a…
Evaluating fundamental life-history traits for Tobacco etch potyvirus
2013
Los virus de ARN son probablemente algunos de los parásitos más extendidos que se pueden encontrar en todas las formas de vida. Estos agentes infecciosos parecen particularmente propensos a causar enfermedades emergentes en plantas, seres humanos y otros animales. Sus habilidades para escapar al sistema inmune, evadir estrategias antivirales o para infectar a nuevas especies son una consecuencia directa de su enorme capacidad para evolucionar rápidamente. Comprender los procesos básicos del cambio evolutivo puede ser unos de los principales pasos necesarios en el diseño de nuevas estrategias de intervención. Desde una perspectiva evolutiva, una de las principales características de los viru…
Clinical Onset and Multiple Sclerosis Relapse after SARS-CoV-2 Infection
2021
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with several neurological disorders including headache, facial palsy, encephalitis, stroke, demyelinating disorders. The present report will discuss cases of multiple sclerosis (MS) onset and relapse both beginning early after SARS-CoV-2 infection. In both cases, magnetic resonance imaging (MRI) showed widespread bilateral subcortical and periventricular active lesions. Serum IgG against SARS-CoV-2 Spike antigens confirmed seroconversion with titers that are considered not definitely protective against possible reinfection. We hypothesize that SARS-CoV-2 infection, as previously reported for other vir…