HAL Université de Tours
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Marek’s disease virus replication in chicken skin reconstructed in vitro: evidence for viral particles in corneocytes
No full textInternational audienceMarek's disease (MD) is a lethal lymphoma of chickens caused by the highly transmissible Gallid alphaherpesvirus 2 (GaAHV-2), commonly known as MD virus (MDV) [12]. In addition to its tropism for lymphoid cells, this virus exhibits a strong tropism for skin epithelial cells [13]. Seven days post-infection, the virus starts to replicate in keratinocytes of feather follicles Abstract Marek's disease (MD) is a lethal lymphoma of chickens, which is caused by MD virus (MDV), an alphaherpesvirus. MDV infects epithelial cells of the skin appendages, notably feather follicles, replicates in these cells and is shed into the environment exclusively from these tissues. Here, we tested whether chicken skin equivalents (SEs) can be used to model MDV infection. Primary chicken keratinocytes were seeded on a suspension of fibroblasts in collagen and induced to terminally differentiate at the air-liquid interface. A recombinant MDV expressing the Katushka fluorescent protein (MDV-KAT) was introduced into SEs by seeding primary keratinocytes together with MDV-KAT-infected keratinocytes of the K8 cell line. KAT-mediated fluorescence increased during the culture of infected SEs, indicating virus infection and replication, while the expression of keratinocyte differentiation markers was not significantly altered by MDV infection. MDV did not spread to the dermal compartment of SEs but localized to the upper layers of the epidermis. Viral particles were readily observed by electron microscopy in living keratinocytes and for the first time in cornified keratinocytes of the outermost layer of infected SEs, suggesting that viral elements can be released into the environment. Finally, we demonstrated that two fluorescent vaccine strains of MDV, Rispens and herpesvirus of turkey, can infect and replicate in SEs. Taken together, this study establishes chicken SEs as an in vitro model for essential steps of MDV infection
Marek’s Disease Virus Replication in Chicken Skin Reconstructed In Vitro: Evidence for Viral Particles in Corneocytes
No full textInternational audienceMarek’s disease (MD) is a lethal lymphoma of chickens, which is caused by MD virus (MDV), an alphaherpesvirus. MDV infects epithelial cells of the skin appendages, notably feather follicles, replicates in these cells and is shed into the environment exclusively from these tissues. Here, we tested whether chicken skin equivalents (SEs) can be used to model MDV infection. Primary chicken keratinocytes were seeded on a suspension of fibroblasts in collagen and induced to terminally differentiate at the air-liquid interface. A recombinant MDV expressing the Katushka fluorescent protein (MDV-KAT) was introduced into SEs by seeding of primary keratinocytes together with MDV-KAT-infected keratinocytes of the K8 cell line. KAT-mediated fluorescence increased during the culture of infected SEs, indicating virus infection and replication, while the expression of keratinocyte differentiation markers was not significantly altered by MDV infection. MDV did not spread to the dermal compartment of SEs, but localized to the upper layers of the epidermis. Viral particles were readily observed by electron microscopy in living keratinocytes and for the first time in cornified keratinocytes of the outermost layer of infected SEs, evidence for excretion of viral elements into environment. Finally, we demonstrated that two fluorescent vaccine strains of MDV, Rispens and herpesvirus of turkey, can infect and replicate in SEs. Taken together, this study establishes chicken SEs as an in vitro model for MDV infection
Pink discoloration defects associated with microbial structure and metabolome changes in commercial bloomy cheeses
No full textInternational audienceThis study investigates pink discoloration defects in French bloomy rind soft cheeses, which can negatively affect product appearance, consumer acceptance, and lead to economic losses. Two batches of cheese from the same processing plant were analyzed: one with visible pink discoloration and one without, allowing for comparative analysis. A multi-omics approach was applied, combining microbial profiling (16S rRNA and ITS2 sequencing) and metabolomics (GC–MS and LC-MS) to identify the factors linked to the defect. Three microbial species showed significant differences in abundance depending on sample type (spoiled and unspoiled) and location on the cheese surface: Penicillium camemberti, Psychrobacter group, and Paeniglutamicibacter gangotriensis. A positive correlation was observed between this group and salt concentration, as well as with multiple metabolites such as butanoic acid, acetic acid, aldehydes, ketones, esters, and terpenes. Notably, P. gangotriensis had never previously been detected in cheese. To test its role, model cheeses were inoculated with or without six strains of P. gangotriensis isolated from cheeses. Model cheeses containing the bacteria developed pink discoloration after 14 days of ripening, while controls remained unchanged after 20 days. These results strongly suggest that P. gangotriensis is responsible for the pink defect. Further research is needed to confirm this hypothesis by identifying the pigment's chemical structure and understanding the biotic and abiotic conditions that promote its production
Le transfert du cimetière communal de Lys-Saint-Georges (Indre), témoin d’un mode de fonctionnement particulier des cimetières ruraux contemporains
No full textInternational audienceUn diagnostic d’archéologie préventive mené « place de l’Église » à Lys-Saint-Georges (Indre) a mis au jour plusieurs sépultures contemporaines, localisées à l’emplacement de l’ancien cimetière communal. Les sondages réalisés ont permis d’appréhender la durée de fonctionnement de cet espace funéraire, tandis que les sources archivistiques et orales documentent les conditions de sa fermeture ainsi que son transfert vers un nouveau site entre 1950 et 1966.Si la documentation archéologique peut, à première vue, surprendre quant aux modalités du déplacement des tombes, elle reflète en réalité une gestion ordinaire et pragmatique des cimetières à l’époque contemporaine. Les sources d’archives montrent, quant à elles, un fonctionnement singulier, peut-être propre aux petites communes rurales
Ti doped LSCF for improvement of Solid Oxide Cell long term stability operated on SOEC condition
No full textInternational audienc
Addiction à la pornographie
No full textInternational audienceFor a small proportion of people, pornography use may be associated with prioritisation of use, loss of control and negative functional consequences. These observations are fuelling concerns about the risk of a possible addiction to pornography. Although the field of research is still evolving, certain variables seem to predict the severity of this addiction, such as craving, the use of pornography for emotional regulation, insecure attachment and moral incongruence. The emergence of new forms of pornography, such as interactive games and virtual reality, could modify the dynamics of use and require in-depth studies to understand better their potential impact in terms of addiction as well as on mental health and sexual well-being.L’usage de la pornographie peut s’associer chez une petite proportion des personnes à une priorisation de l’usage, à une perte de contrôle et à des conséquences fonctionnelles négatives. Ces observations alimentent des préoccupations quant au risque d’une possible addiction à la pornographie. Bien que le champ de recherche demeure en évolution, certaines variables semblent prédire la sévérité de cette addiction, telles que le craving, l’usage de la pornographie pour la régulation émotionnelle, l’attachement insécure et l’incongruence morale. L’émergence de nouvelles formes de pornographie, comme les jeux interactifs et la réalité virtuelle, pourrait modifier les dynamiques d’usage et nécessiter des études approfondies pour mieux comprendre leur potentiel impact en termes d’addiction ainsi que sur la santé mentale et le bien-être sexuel
Ultrastructural Expansion Microscopy (U-ExM): new insight for the nanoscale characterization of host-pathogen interactions
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Exact Evaluation of the Accuracy of Diffusion Models for Inverse Problems with Gaussian Data Distributions
No full textUsed as priors for Bayesian inverse problems, diffusion models have recently attracted considerable attention in the literature. Their flexibility and high variance enable them to generate multiple solutions for a given task, such as inpainting, super-resolution, and deblurring. However, several unresolved questions remain about how well they perform. In this article, we investigate the accuracy of these models when applied to a Gaussian data distribution for deblurring.Within this constrained context, we are able to precisely analyze the discrepancy between the theoretical resolution of inverse problems and their resolution obtained using diffusion models by computing the exact Wasserstein distance between the distribution of the diffusion model sampler and the ideal distribution of solutions to the inverse problem. Our findings allow for the comparison of different algorithms from the literature
