Impact of infection on proteome-wide glycosylation revealed by distinct signatures for bacterial and viral pathogens

Mechanisms of infection and pathogenesis have predominantly been studied based on differential gene or protein expression. Less is known about posttranslational modifications, which are essential for protein functional diversity. We applied an innovative glycoproteomics method to study the systemic proteome-wide glycosylation in response to infection. The protein site-specific glycosylation was characterized in plasma derived from well-defined controls and patients. We found 3862 unique features, of which we identified 463 distinct intact glycopeptides, that could be mapped to more than 30 different proteins. Statistical analyses were used to derive a glycopeptide signature that enabled significant differentiation between patients with a bacterial or viral infection. Furthermore, supported by a machine learning algorithm, we demonstrated the ability to identify the causative pathogens based on the distinctive host blood plasma glycopeptide signatures. These results illustrate that glycoproteomics holds enormous potential as an innovative approach to improve the interpretation of relevant biological changes in response to infection

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BackgroundThe PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.MethodsFebrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.FindingsOf 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.InterpretationMost febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.FundingEU Horizon 2020 grant 668303

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Elaboration of a new kind of stimuli-responsive surfaces responding to a mechanical stimulus

Un matériau adaptatif ou « intelligent » est capable de modifier spontanément ses propriétés physico-chimiques en réponse à un stimulus (température, pH, etc.). Les surfaces sensibles à un stimulus mécanique constituent une nouvelle catégorie de matériaux adaptatifs capables de montrer des changements de propriétés de surface sous l'effet d'une contrainte mécanique. Dans ce contexte, ces travaux se concentrent sur l'adsorption d'objets biologiques tels que des protéines sur un support élastique. L'objectif étant de contrôler cette adsorption en fonction du taux d'étirement du substrat. Les élastomères de silicone (PDMS), de par leur élasticité et leur faible toxicité, constituent des supports de choix pour l'élaboration de telles surfaces. Ces matériaux polymère sont largement utilisés dans le domaine médical et en microfluidique.La première étape d'élaboration consiste à rendre la surface du support de PDMS chimiquement réactive. Pour des temps de traitement courts, la polymérisation plasma de l'anhydride maléique permet d'introduire des groupements réactifs à la surface du PDMS, tout en conservant ses propriétés élastiques à l'échelle locale.Les substrats de PDMS traités présentent des propriétés acide-base de surface qui sont caractéristiques des groupements diacide du film polymère plasma. Le degré d'ionisation et les propriétés d'adhésion de ces surfaces sont étudiés en fonction du pH. L'évolution de ces propriétés sous élongation atteste de l'effet de dilution des groupements réactifs de surface.Le support étirable et réactif est ensuite fonctionnalisé avec des systèmes constitués de polymères et de récepteurs spécifiques. D'une part, les chaînes de poly(éthylèneglycol) (Peg) présentent des propriétés de résistance à l'adsorption de protéines. D'autre part, la biotine est un récepteur capable de se lier spécifiquement à une protéine, la streptavidine. En combinant le greffage covalent des Pegs et de la biotine sur le substrat de PDMS, on obtient une surface bi-fonctionnelle. L'objectif est de masquer la biotine avec les Pegs lorsque le substrat est à l'état relaxé, puis de promouvoir l'adsorption spécifique de la streptavidine sous élongation, afin d'obtenir un système de reconnaissance moléculaire sensible à un stimulus mécanique.Surface responsive materials have the property to show response mechanisms triggered by external stimuli (temperature, pH, etc.). Mechanically responsive surfaces are a new kind of stimuli-responsive materials, which surface properties change in response to mechanical stress. This work focuses on the controlled adsorption of biological objects such as proteins on an elastic substrate. The goal is to control adsorption as a function of the elongation of the substrate. In elaborating mechanically responsive materials, silicone elastomers (PDMS) constitute interesting substrates because of their high flexibility and low toxicity. These polymers are widely used in biomedical devices and in microfluidics.The first step of elaboration consists in making the PDMS substrate chemically reactive. For low treatment time, plasma polymerization of maleic anhydride leads to the introduction of reactive groups on PDMS surface, while maintaining elastic properties at local scale.Treated PDMS substrates show acide-base properties which are characteristic of the diacid groups from the plasma polymer thin film. The degree of ionization and the adhesion properties of the surface are studied as a function of pH. The evolution of these properties under elongation attests from the dilution effect of surface reactive groups.The stretchable and reactive substrate is then functionalized with systems made of polymers and specific receptors. Poly(ethyleneglycol) (Peg) chains are well known to resist to protein adsorption, whereas biotin receptors bind specifically streptavidinproteins. A bi-functional surface is obtained by combining covalent grafting of Pegs and biotine on the PDMS substrate. The goal is to mask biotin with Peg chains in the relaxed state, while promoting specific binding of streptavidin under elongation of the substrate. This material may constitute a molecular recognition system that responds to a mechanical stimulus

Elaboration d'une nouvelle catégorie de surfaces adaptives sensibles à un stimulus mécanique

Surface responsive materials have the property to show response mechanisms triggered by external stimuli (temperature, pH, etc.). Mechanically responsive surfaces are a new kind of stimuli-responsive materials, which surface properties change in response to mechanical stress. This work focuses on the controlled adsorption of biological objects such as proteins on an elastic substrate. The goal is to control adsorption as a function of the elongation of the substrate. In elaborating mechanically responsive materials, silicone elastomers (PDMS) constitute interesting substrates because of their high flexibility and low toxicity. These polymers are widely used in biomedical devices and in microfluidics.The first step of elaboration consists in making the PDMS substrate chemically reactive. For low treatment time, plasma polymerization of maleic anhydride leads to the introduction of reactive groups on PDMS surface, while maintaining elastic properties at local scale.Treated PDMS substrates show acide-base properties which are characteristic of the diacid groups from the plasma polymer thin film. The degree of ionization and the adhesion properties of the surface are studied as a function of pH. The evolution of these properties under elongation attests from the dilution effect of surface reactive groups.The stretchable and reactive substrate is then functionalized with systems made of polymers and specific receptors. Poly(ethyleneglycol) (Peg) chains are well known to resist to protein adsorption, whereas biotin receptors bind specifically streptavidinproteins. A bi-functional surface is obtained by combining covalent grafting of Pegs and biotine on the PDMS substrate. The goal is to mask biotin with Peg chains in the relaxed state, while promoting specific binding of streptavidin under elongation of the substrate. This material may constitute a molecular recognition system that responds to a mechanical stimulus.Un matériau adaptatif ou « intelligent » est capable de modifier spontanément ses propriétés physico-chimiques en réponse à un stimulus (température, pH, etc.). Les surfaces sensibles à un stimulus mécanique constituent une nouvelle catégorie de matériaux adaptatifs capables de montrer des changements de propriétés de surface sous l'effet d'une contrainte mécanique. Dans ce contexte, ces travaux se concentrent sur l'adsorption d'objets biologiques tels que des protéines sur un support élastique. L'objectif étant de contrôler cette adsorption en fonction du taux d'étirement du substrat. Les élastomères de silicone (PDMS), de par leur élasticité et leur faible toxicité, constituent des supports de choix pour l'élaboration de telles surfaces. Ces matériaux polymère sont largement utilisés dans le domaine médical et en microfluidique.La première étape d'élaboration consiste à rendre la surface du support de PDMS chimiquement réactive. Pour des temps de traitement courts, la polymérisation plasma de l'anhydride maléique permet d'introduire des groupements réactifs à la surface du PDMS, tout en conservant ses propriétés élastiques à l'échelle locale.Les substrats de PDMS traités présentent des propriétés acide-base de surface qui sont caractéristiques des groupements diacide du film polymère plasma. Le degré d'ionisation et les propriétés d'adhésion de ces surfaces sont étudiés en fonction du pH. L'évolution de ces propriétés sous élongation atteste de l'effet de dilution des groupements réactifs de surface.Le support étirable et réactif est ensuite fonctionnalisé avec des systèmes constitués de polymères et de récepteurs spécifiques. D'une part, les chaînes de poly(éthylèneglycol) (Peg) présentent des propriétés de résistance à l'adsorption de protéines. D'autre part, la biotine est un récepteur capable de se lier spécifiquement à une protéine, la streptavidine. En combinant le greffage covalent des Pegs et de la biotine sur le substrat de PDMS, on obtient une surface bi-fonctionnelle. L'objectif est de masquer la biotine avec les Pegs lorsque le substrat est à l'état relaxé, puis de promouvoir l'adsorption spécifique de la streptavidine sous élongation, afin d'obtenir un système de reconnaissance moléculaire sensible à un stimulus mécanique

VERIFICAÇÃO DA POSSIBILIDADE DE VALIDAÇÃO DO SISTEMA DAVID® COMO INSTRUMENTO AVALIATIVO EM DIAGNÓSTICO ORTOPÉDICO NO PROCESSO DE REINTEGRAÇÃO PARA O TRABALHO – ESTUDO PILOTO

Esta investigação teve o propósito de assistir a avaliação física e capacidades funcionais, para a validação de sintomas em diagnósticos ortopédicos dentro do processo de reintegração para o trabalho. A análise do estado funcional da coluna vertebral de uma amostra aleatória de 236 pacientes, através da medição da força máxima isométrica utilizando o Sistema DAVID® de Avaliação foi feita levando em consideração o estado sócio-econômico dos pacientes. O protocolo de teste está coerente com o relatório da avaliação do Centro de Rehabilitação. Os dados da análise funcional biomecânica foram encontrados com auxílio do programa Excel. De acordo com o breve estudo desenvolvido é possível dizer que existe uma significativa diferença no desenvolvimento de força máxima durante o movimento de rotação do tronco (para a direita, p = 0,018; para a esquerda, p = 0,046) entre os grupos sócio-econômicos “empregados” ou “desempregados” nos pacientes com dor na parte inferior das costas. Uma vez que o estudo não pode comprovar correlação entre dor crônica da região lombar e desenvolvimento da força, a particularidade patológica em questão permanece irrelevante

Verificação da possibilidade de validação do sistema DAVID® como instrumento avaliativo em diagnóstico ortopédico no processo de reintegração para o trabalho – estudo piloto

This research aimed to support the physical assessment and functional capabilities, for the validation of symptoms in orthopaedic diagnoses in the process of reintegration for the work. Analysis of the functional state of the vertebral column of a random sample of 236 patients, through the measurement of the maximum isometric force using the Assessment System DAVID® was accomplished taking into account the socio-economic status of these patients. The test protocol is coherent with the report of the Rehabilitation Center assessment. The data of biomechanical functional analysis were found using the Excel program. In accordance with the brief study developed it is possible to say that there is a significant difference in the development of maximum strength during rotation movement of the trunk (to the right, p = 0,018; to the left, p = 0,046) between the socio-economic groups “employees” or “unemployed” in patients with low back pain. Since the study is not able to demonstrate correlation between chronic pain of the lumbar region and strength development, the concerned pathological special features remains irrelevant.Esta investigação teve o propósito de assistir a avaliação física e capacidades funcionais, para a validação de sintomas em diagnósticos ortopédicos dentro do processo de reintegração para o trabalho. A análise do estado funcional da coluna vertebral de uma amostra aleatória de 236 pacientes, através da medição da força máxima isométrica utilizando o Sistema DAVID® de Avaliação foi feita levando em consideração o estado sócio-econômico dos pacientes. O protocolo de teste está coerente com o relatório da avaliação do Centro de Rehabilitação. Os dados da análise funcional biomecânica foram encontrados com auxílio do programa Excel. De acordo com o breve estudo desenvolvido é possível dizer que existe uma significativa diferença no desenvolvimento de força máxima durante o movimento de rotação do tronco (para a direita, p = 0,018; para a esquerda, p = 0,046) entre os grupos sócio-econômicos “empregados” ou “desempregados” nos pacientes com dor na parte inferior das costas. Uma vez que o estudo não pode comprovar correlação entre dor crônica da região lombar e desenvolvimento da força, a particularidade patológica em questão permanece irrelevante

Preclinical In Vitro Assessment of Submicron-Scale Laser Surface Texturing on Ti6Al4V

Loosening of orthodontic and orthopedic implants is a critical and common clinical problem. To minimize the numbers of revision surgeries due to peri-implant inflammation or insufficient osseointegration, developments of new implant manufacturing strategies are indicated. Ultrafast laser surface texturing is a promising contact-free technology to modify the physicochemical properties of surfaces toward an anti-infectious functionalization. This work aims to texture Ti6Al4V surfaces with ultraviolet (UV) and green (GR) radiation for the manufacturing of laser-induced periodic surface structures (LIPSS). The assessment of these surface modifications addresses key aspects of topography, morphology and chemical composition. Human primary mesenchymal stromal cells (hMSCs) were cultured on laser-textured and polished Ti6Al4V to characterize the surfaces in terms of their in vitro biocompatibility, cytotoxicity, and metal release. The outcomes of the in vitro experiment show the successful culture of hMSCs on textured Ti6Al4V surfaces developed within this work. Cells cultured on LIPSS surfaces were not compromised in terms of their viability if compared to polished surfaces. Yet, the hMSC culture on UV-LIPSS show significantly lower lactate dehydrogenase and titanium release into the supernatant compared to polished. Thus, the presented surface modification can be a promising approach for future applications in orthodontics and orthopedics

Biomimetic Cryptic Site Surfaces for Reversible Chemo- and Cyto-Mechanoresponsive Substrates

International audienceChemo-mechanotransduction, the way by which mechanical forces are transformed into chemical signals, plays a fundamental role in many biological processes. The first step of mechanotransduction often relies on exposure, under stretching, of cryptic sites buried in adhesion proteins. Likewise, here we report the first example of synthetic surfaces allowing for specific and fully reversible adhesion of proteins or cells promoted by mechanical action. Silicone sheets are first plasma treated and then functionalized by grafting sequentially under stretching poly(ethylene glycol) (PEG) chains and biotin or arginine-glycine-aspartic acid (RGD) peptides. At unstretched position, these ligands are not accessible for their receptors. Under a mechanical deformation, the surface becomes specifically interactive to streptavidin, biotin antibodies, or adherent for cells, the interactions both for proteins and cells being fully reversible by stretching/unstretching, revealing a reversible exposure process of the ligands. By varying the degree of stretching, the amount of interacting proteins can be varied continuously