Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

Etude biochimique et structurale de l'éjection de l'ADN de SPP1

Les bactériophages à queue ainsi que les virus herpès présentent des mécanismes moléculaires d'assemblage similaires. Le génome viral est encapsidé à travers un pore portal situé à un sommet spécialisé d'une procapside préalablement constituée. Pour empêcher le relargage de l'ADN le canal portal doit être rapidement fermé. Dans le cas du bactériophage SPP1 qui infecte Bacillus subtilis les protéines gp15 et gp16 se fixent sur la protéine portale gp6. La protéine gp16 ferme le canal portal. Lors de l'infection, le bactériophage SPP1 reconnaît le récepteur YueB à la surface de B. subtilis.Afin de mettre en place un système d'éjection in vitro de l'ADN de SPP1 nous avons purifié l'ectodomaine du récepteur YueB. Ce domaine est un dimère soluble formant une fibre allongée. Il se fixe au niveau de la fibre caudale de la queue de SPP1 et provoque l'éjection de l'ADN du phage.Nous avons également produit et purifié la protéine gp16 biologiquement active. Gp16 est un monomère. Elle a été produite en milieu enrichi aux isotopes 13C-15N et deutéré pour des analyses de RMN. L'attribution des résonances de la protéine s'est avérée être un cas particulèrement complexe mais nous a permis de proposer un modèle de repliement comprenant une petite hélice a et sept brins b parmi lesquels trois forment un feuillet. Une structure affinée de gp16 superposée aux structures à basses résolutions obtenues aux différentes étapes de la vie de SPP1 permettra de comprendre le maintien du génome dans la capside virale lors de l'assemblage puis sa libération dans la cellule hôte au moment de l'infection.Tailed bacteriophages and herpes viruses follow a similar morphogenesis pathway. During their assembly the viral DNA is packaged in a preformed procapsid through the central channel of a portal protein localized asymmetrically at one of the twelve vertices of the viral capsid. At the end of the encapsidation the portal channel has to be closed shortly to avoid the ejection of DNA from the phage particles. In the bacteriophage SPP1 the protein gp15 binds to the portal protein gp6 extending the portal channel that is then closed by attachment of gp16 to gp15. During infection, SPP1 recognizes the YueB receptor on the surface of its Gram-positive host cell, the bacterium Bacillus subtilis. The tail tip, distal from the capsid interacts with YueB.To reproduce in vitro the ejection of DNA from virions we purified the ectodomain of the SPP1 receptor, YueB. This domain is a soluble dimer. Electron micrograph showed that it is an elongated fiber.We also set up a protocol for the production and the purification of biologically active gp16. Gp16 is a monomer in solution. In order to get a labeled protein for NMR analysis, gp16 was produced in medium supplemented with 13C-15N and 2H. Residue assignment proves to be complicate but allowed us to submit a model of structure showing one a helix and seven b strands.A high resolution structure of the protein gp16 fitted into low resolution structures obtained at different stages of the SPP1 life cycle, and after DNA ejection, will allow us to understand how the genome is kept inside the viral capsid during the assembly and how it is released from the virion during infection.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

L'acte homicide-suicide (revue de la littérature)

ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Overexpression of Spock2 in mice leads to altered lung alveolar development and worsens lesions induced by hyperoxia: over expression of Spock2 and altered lung development

International audienceSPARC/osteonectin, cwcv and kazal-like domains proteoglycan 2 (SPOCK2) was previously associated with genetic susceptibility to bronchopulmonary dysplasia in a French population of very preterm neonates. Its expression increases during lung development and is increased after exposure of rat pups to hyperoxia compared with controls bred in room air. To further investigate the role of SPOCK2 during lung development, we designed two mouse models, one that uses a specific anti-Spock2 antibody and one that reproduces the hyperoxia-induced Spock2 expression with a transgenic mouse model resulting in a conditional and lung-targeted overexpression of Spock2. When mice were bred under hyperoxic conditions, treatment with anti-Spock2 antibodies significantly improved alveolarization. Lung overexpression of Spock2 altered alveolar development in pups bred in room air and worsened hyperoxia-induced lesions. Neither treatment with anti-Spock2 antibody nor overexpression of Spock2 was associated with abnormal activation of matrix metalloproteinase-2. These two models did not alter the expression of known players in alveolar development. This study brings strong arguments for the deleterious role of SPOCK2 on lung alveolar development especially after lung injury, suggesting its role in bronchopulmonary dysplasia susceptibility. These effects are not mediated by a deregulation in metalloproteases activity and in expression of factors essential to normal alveolarization. The balance between types 1 and 2 epithelial alveolar cells may be involved

Diversité des acteurs et des politiques de la petite enfance : vers une gouvernance partenariale et négociée ? Rapport final

Ces dernières décennies, la notion de gouvernance a fait son apparition dans de nombreux débats publics. Notion polysémique, la gouvernance est souvent utilisée pour désigner l’ensemble des interactions entre une diversité croissante d’acteurs publics et privés dans l’élaboration et la mise en œuvre des politiques publiques (Le Galès, 1995 ; Kooiman, 2003 ; Gaudin, 2004 ; Enjolras, 2005). Cette notion reflète ainsi un changement dans le mode de gestion de l’action collective et dans sa perception par les acteurs concernés, comme les usagers, les bénéficiaires ou les observateurs. Elle souligne non seulement la diversité des acteurs, la nature interactive des processus d’élaboration des politiques et les niveaux légitimes de l’action publique mais aussi l’ensemble des modalités institutionnelles dans lequel ces politiques s’inscrivent (Enjolras, 2005, p. 56). Elle permet de mieux appréhender la diversité et la complexité qui caractérisent aujourd’hui l’action publique (Kooiman, 2003). Ces évolutions se retrouvent dans différents champs de l’action publique, en particulier dans celui de la protection sociale et visent une meilleure allocation des ressources publiques dans un contexte général de maîtrise de l’évolution des dépenses sociales (Palier, 2002).L’objectif de cette recherche est d’étudier les régimes de gouvernance à l’œuvre dans le champ de la petite enfance, leur évolution et les enjeux collectifs qui en découlent, notamment en termes de cohérence par rapport aux finalités de l’accueil et d’équité dans l’accès aux services et ce, dans plusieurs départements. Par régime de gouvernance, nous entendons l’ensemble des modalités de coordination et d’interaction des acteurs qui visent la réalisation de l’intérêt général au niveau d’un secteur, ici la petite enfance, ou d’une collectivité (Enjolras, 2005). [...

The ectodomain of the viral receptor YueB forms a fiber that triggers ejection of bacteriophage SPP1 DNA

The irreversible binding of bacteriophages to their receptor( s) in the host cell surface triggers release of the naked genome from the virion followed by transit of viral DNA to the host cell cytoplasm. We have purified, for the first time, a receptor from a Gram-positive bacterium that is active to trigger viral DNA ejection in vitro. This extracellular region ("ectodomain") of the Bacillus subtilis protein YueB ( YueB780) was a 7 S elongated dimer forming a 36.5-nm-long fiber. YueB780 bound to the tail tip of bacteriophage SPP1. Although a stable receptor-phage interaction occurred between 0 and 37 degrees C, complete blocking of phage DNA release or partial ejection events were observed at temperatures below 15 degrees C. We also showed that the receptor was exposed to the B. subtilis surface. YueB differed structurally from phage receptors from Gram-negative bacteria. Its properties revealed a fiber spanning the full length of the 30-nm-thick peptidoglycan layer. The fiber is predicted to be anchored in the cell membrane through transmembrane segments. These features, highly suitable for a virus receptor in Gram-positive bacteria, are very likely shared by a large number of phage receptors

RH mapping by sequencing: chromosome-scale assembly of the duck genome

Like many other species, the duck genome has been sequenced thanks to the technological breakthrough provided by the emergence of Next Generation Sequencing (NGS). The resulting de novo assemblies are however made of thousands of scattered scaffolds. To achieve chromosome-scale contiguity, long-range intermediate genome maps remain indispensable. Radiation Hybrid (RH) maps have been used to assist the generation of chromosome-scale genome assemblies by taking advantage of the high density SNP chips that provide a large number of markers that can be efficiently genotyped on the panel. In the absence of such a resource in duck, we sequenced 100 hybrid clones of a duck RH panel enabling direct genotyping of the assembly scaffolds on the panel. The rationale is to use scaffolds as markers and to genotype the scaffolds by sequencing the clones: the presence/absence of a scaffold in a particular sequenced hybrid is attested by the presence/absence of reads mapping specifically to this scaffold. The detection of scaffolds exhibiting a chromosomal breakage resulting from the irradiation process revealed itself to be a critical issue of this genotyping by sequencing process. This process resulted in the construction of RH vectors for 2,027 scaffolds, representing a total of about 1 Gb of sequences (95% of the current Duck genome assembly). The subsequent linkage analysis enabled the construction of RH maps and therefore to organize, i.e. order and orient, the scaffolds into pseudomolecules associated to the corresponding duck chromosomes. We describe here the whole mapping process, from sequence-based genotyping to the construction of comparative maps, as well as few examples of intra-chromosomal rearrangements that have been identified by the comparison with the chicken, turkey and zebra finch genomes and subsequently confirmed by FISH. We describe a method to order and orient sequence scaffolds into super-scaffolds spanning entire chromosomes. The method, which requires a pre-existing RH panel and sequence scaffolds from an NGS assembly, relies on a shallow sequencing of the RH clones. This approach was applied to the duck genome and produced chromosome-scale scaffolds for 29 out of the 41 duck chromosomes

Amor Romanus – Amours romaines

Presque un demi-siècle après la publication du classique de Pierre Grimal, L’Amour à Rome, et vingt-cinq ans après la sortie retentissante du livre de Paul Veyne, L’Élégie érotique romaine, il nous a paru opportun de renouveler la question en composant un recueil d’études sur l’amour romain : sur l’expression littéraire proprement romaine de l’amour, sur la perception romaine de l’amour, comme passion ou comme jeu, de Varron à saint Ambroise. Car, depuis un certain temps, on disserte beaucoup de la « sexualité » à Rome, on dispute savamment de la pertinence à Rome de la distinction hétérosexualité/homosexualité, mais on semble éluder une notion mi-âme mi-corps – et un nom, amor, encore très présent dans notre aire romano-méditerranéenne –, sans doute trop subtile pour ne pas effrayer les amateurs de schémas et de systèmes anthropologiques. Les quinze contributions proposées sont suivies d’une anthologie – sous forme d’abécédaire de l’amour à Rome –, en présentation bilingue

Structure of bacteriophage SPP1 tail reveals trigger for DNA ejection

The majority of known bacteriophages have long noncontractile tails (Siphoviridae) that serve as a pipeline for genome delivery into the host cytoplasm. The tail extremity distal from the phage head is an adsorption device that recognises the bacterial receptor at the host cell surface. This interaction generates a signal transmitted to the head that leads to DNA release. We have determined structures of the bacteriophage SPP1 tail before and after DNA ejection. The results reveal extensive structural rearrangements in the internal wall of the tail tube. We propose that the adsorption device–receptor interaction triggers a conformational switch that is propagated as a domino-like cascade along the 1600 Å-long helical tail structure to reach the head-to-tail connector. This leads to opening of the connector culminating in DNA exit from the head into the host cell through the tail tube

Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs.

Life-threatening 'breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS-CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals (age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto-Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-α2 and IFN-ω, while two neutralized IFN-ω only. No patient neutralized IFN-β. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population