Co-evolutionary analysis suggests a role for TLR9 in papillomavirus restriction

Upon infection, DNA viruses can be sensed by pattern recognition receptors (PRRs) leading to the activation of type I and III interferons, aimed at blocking infection. Therefore, viruses must inhibit these signaling pathways, avoid being detected, or both. Papillomavirus virions are trafficked from early endosomes to the Golgi apparatus and wait for the onset of mitosis to complete nuclear entry. This unique subcellular trafficking strategy avoids detection by cytoplasmic PRRs, a property that may contribute to establishment of infection. However, as the capsid uncoats within acidic endosomal compartments, the viral DNA may be exposed to detection by toll-like receptor (TLR) 9. In this study we characterize two new papillomaviruses from bats and use molecular archeology to demonstrate that their genomes altered their nucleotide composition to avoid detection by TLR9, providing evidence that TLR9 acts as a PRR during papillomavirus infection. Furthermore, we demonstrate that TLR9, like other components of the innate immune system, is under evolutionary selection in bats, providing the first direct evidence for co-evolution between papillomaviruses and their hosts

The westward journey of alfalfa leaf curl virus

Alfalfa leaf curl virus (ALCV), which causes severe disease symptoms in alfalfa (Medicago sativa L.) and is transmitted by the widespread aphid species, Aphis craccivora Koch, has been found throughout the Mediterranean basin as well as in Iran and Argentina. Here we reconstruct the evolutionary history of ALCV and attempt to determine whether the recent discovery and widespread detection of ALCV is attributable either to past diagnostic biases or to the emergence and global spread of the virus over the past few years. One hundred and twenty ALCV complete genome sequences recovered from ten countries were analyzed and four ALCV genotypes (ALCV-A, ALCV-B, ALCV-C, and ALCV-D) were clearly distinguished. We further confirm that ALCV isolates are highly recombinogenic and that recombination has been a major determinant in the origins of the various genotypes. Collectively, the sequence data support the hypothesis that, of all the analyzed locations, ALCV likely emerged and diversified in the Middle East before spreading to the western Mediterranean basin and Argentina

Diverse genomoviruses representing twenty-nine species identified associated with plants

Genomoviruses (family Genomoviridae) are circular single-stranded DNA viruses that have been mainly identifed through metagenomics studies in a wide variety of samples from various environments. Here, we describe 98 genomes of genomoviruses found associated with members of 19 plant families from Australia, Brazil, France, South Africa and the USA. These 98 genomoviruses represent 29 species, 26 of which are new, in the genera Gemykolovirus (n = 37), Gemyduguivirus (n = 9), Gemygorvirus (n = 8), Gemykroznavirus (n = 6), Gemycircularvirus (n = 21) and Gemykibivirus (n = 17)

Corrosion et altération des matériaux du nucléaire

International audienceLa maîtrise du phénomène de la corrosion est cruciale pour l'industrie nucléaire : il y va du rendement des installations, mais aussi de leur sûreté.Le nucléaire est confronté à la corrosion pour une grande variété de matériaux placés dans des environnements très divers. La corrosion métallique est, bien sûr, à l’œuvre dans le milieu chaud et aqueux des réacteurs à eau qui constituent l'essentiel du parc mondial. Les progrès réalisés dans la maîtrise de la corrosion des différents composants de ces réacteurs permettent de les faire fonctionner dans des conditions plus sûres. la corrosion est aussi présente dans les installations de l'aval du cycle électronucléaire (corrosion en milieu acide dans les usines de retraitement, corrosion des conteneurs de déchets en situation d'entreposage ou de stockage, etc.). Les systèmes nucléaires du futur élargiront encore la palette des matériaux à étudier et des situations dans lesquelles ils seront placés (corrosion par les métaux liquides ou les impuretés de l'hélium).La corrosion ressemble souvent dans sa description à un patchwork de cas particuliers. Les problèmes de corrosion rencontrés et leurs études sont présentés ici dans des chapitres relatifs aux grands secteurs du domaine nucléaire et y sont classés en fonction de leur phénoménologie. Cette monographie illustre les recherches en cours en présentant les résultats marquants obtenus récemment

The effect of salivary bypass tube use on the prevention of pharyngo-cutaneous fistulas after total laryngectomy

Introduction: The aim of this retrospective study was to assess the efficacy of Salivary Bypass Tube (SBT) for preventing pharyngo-cutaneous fistula (PCF) in a recent cohort of patients who underwent primary and salvage total laryngectomy (TL). Methods: A consecutive series of 133 patients who underwent total laryngectomy between 1997 and 2019 was reviewed. The incidence of PCF was compared between patients who did not receive SBT (nSBT group; n = 55) and those preventively receiving SBT (SBT group; n = 78) in both primary and salvage TL. Risk factors for PCF were evaluated in a univariate and multivariate analyses. Results: The overall PCF rate was 30%. Preoperative characteristics were similar between the nSBT and SBT groups, except for older age (p = 0.016), lower preoperative hemoglobin (p = 0.043), and lesser neoadjuvant chemotherapy (p = 0.015) in the SBT group. The rate of PCF the nSBT group, was 41.5%, compared to 21.8% in the SBT group (p = 0.020). In multivariate analysis, only the use of SBT was associated with lower risk of PCF (OR = 0.41 (95% CI 0.19–0.89), p = 0.026). This effect was verified only in the subgroup of patient operated for salvage TL (OR = 0.225; 95% CI 0.09–0.7; p = 0.008). Conclusion: The use of SBT in our series in salvage TL, appears to be associated with a decreased risk of PCF.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Co-evolutionary analysis suggests a role for TLR9 in papillomavirus restriction

Upon infection, DNA viruses can be sensed by pattern recognition receptors (PRRs) leading to the activation of type I and III interferons, aimed at blocking infection. Therefore, viruses must inhibit these signaling pathways, avoid being detected, or both. Papillomavirus virions are trafficked from early endosomes to the Golgi apparatus and wait for the onset of mitosis to complete nuclear entry. This unique subcellular trafficking strategy avoids detection by cytoplasmic PRRs, a property that may contribute to establishment of infection. However, as the capsid uncoats within acidic endosomal compartments, the viral DNA may be exposed to detection by toll-like receptor (TLR) 9. In this study we characterize two new papillomaviruses from bats and use molecular archeology to demonstrate that their genomes altered their nucleotide composition to avoid detection by TLR9, providing evidence that TLR9 acts as a PRR during papillomavirus infection. Furthermore, we demonstrate that TLR9, like other components of the innate immune system, is under evolutionary selection in bats, providing the first direct evidence for co-evolution between papillomaviruses and their hosts

Estimation de la situation du SRAS-CoV-2 en France

Traduction non relue par les auteurs de "Estimating the burden of SARS-CoV-2 in France" paru dans Science https://science.sciencemag.org/content/369/6500/208 Date de parution : 10 juillet 2020 DOI: 10.1126/science.abc3517[ATTENTION : LA TRADUCTION DE L'ARTICLE N'A PAS ÉTÉ RELUE PAR LES AUTEURS]. La France a été fortement affectée par la pandémie du syndrome respiratoire aigu sévère coronavirus 2 (SRAS-CoV-2) et est entrée en confinement le 17 mars 2020. À l'aide de modèles appliqués aux données hospitalières et de décès, nous estimons l'impact du confinement et l'immunité actuelle de la population . Nous constatons que 2,9% des personnes infectées sont hospitalisées et 0,5% des personnes infectées décèdent (intervalle de confiance à 95%: 0,3 à 0,9%), allant de 0,001% chez les moins de 20 ans à 8,3% chez les 80 ans ou plus âgés. À tous les âges, les hommes sont plus susceptibles d'être hospitalisés, d'entrer en soins intensifs et de mourir que les femmes. Le confinement a réduit la reproductivité de 2,90 à 0,67 (réduction de 77%). D'ici le 11 mai 2020, date à laquelle les interventions devraient être assouplies, nous prévoyons que 3,5 millions de personnes (fourchette: 2,1 millions à 6,0 millions), soit 5,3% de la population (fourchette: 3,3 à 9,3%), auront été infectées. L'immunité de la population semble insuffisante pour éviter une deuxième vague si toutes les mesures de contrôle sont relâchées à la fin du confinement

Réduire la néophobie des dindes au moment des transitions alimentaires en prenant en compte les caractéristiques visuelles et tactiles des aliments

Texte intégral sur CD ROM p:660-664Réduire la néophobie des dindes au moment des transitions alimentaires en prenant en compte les caractéristiques visuelles et tactiles des aliments. 10. Journées de la Recherche Avicole et Palmipèdes à Foie Gra