A model for the molecular organisation of the IS911 transpososome

Tight regulation of transposition activity is essential to limit damage transposons may cause by generating potentially lethal DNA rearrangements. Assembly of a bona fide protein-DNA complex, the transpososome, within which transposition is catalysed, is a crucial checkpoint in this regulation. In the case of IS911, a member of the large IS3 bacterial insertion sequence family, the transpososome (synaptic complex A; SCA) is composed of the right and left inverted repeated DNA sequences (IRR and IRL) bridged by the transposase, OrfAB (the IS911-encoded enzyme that catalyses transposition). To characterise further this important protein-DNA complex in vitro, we used different tagged and/or truncated transposase forms and analysed their interaction with IS911 ends using gel electrophoresis. Our results allow us to propose a model in which SCA is assembled with a dimeric form of the transposase. Furthermore, we present atomic force microscopy results showing that the terminal inverted repeat sequences are probably assembled in a parallel configuration within the SCA. These results represent the first step in the structural description of the IS911 transpososome, and are discussed in comparison with the very few other transpososome examples described in the literature

Risk factors for infection, predictors of severe disease, and antibody response to COVID-19 in patients with inflammatory rheumatic diseases in Portugal: a multicenter, nationwide study

Copyright © 2022 Cruz-Machado, Barreira, Bandeira, Veldhoen, Gomes, Serrano, Duarte, Rato, Miguel Fernandes, Garcia, Pinheiro, Bernardes, Madeira, Miguel, Torres, Bento Silva, Pestana, Almeida, Mazeda, Cunha Santos, Pinto, Sousa, Parente, Sequeira, Santos, Fonseca and Romão. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Objective: To identify risk factors for SARS-CoV-2 infection and for severe/critical COVID-19, and to assess the humoral response after COVID-19 in these patients. Methods: Nationwide study of adult patients with inflammatory RMDs prospectively followed in the Rheumatic Diseases Portuguese Register-Reuma.pt-during the first 6 months of the pandemic. We compared patients with COVID-19 with those who did not develop the disease and patients with mild/moderate disease with those exhibiting severe/critical COVID-19. IgG antibodies against SARS-CoV-2 were measured ≥3 months after infection and results were compared with matched controls. Results: 162 cases of COVID-19 were registered in a total of 6,363 appointments. Patients treated with TNF inhibitors (TNFi; OR = 0.160, 95% CI 0.099-0.260, P < 0.001) and tocilizumab (OR 0.147, 95% CI 0.053-0.408, P < 0.001) had reduced odds of infection. Further, TNFi tended to be protective of severe and critical disease. Older age, major comorbidities, and rituximab were associated with an increased risk of infection and worse prognosis. Most patients with inflammatory RMDs (86.2%) developed a robust antibody response. Seroconversion was associated with symptomatic disease (OR 13.46, 95% CI 2.21-81.85, P = 0.005) and tended to be blunted by TNFi (OR 0.17, 95% CI 0.03-1.05; P = 0.057). Conclusions: TNFi and tocilizumab reduced the risk of infection by SARS-CoV-2. Treatment with TNFi also tended to reduce rates of severe disease and seroconversion. Older age, general comorbidities and rituximab were associated with increased risk for infection and worse prognosis, in line with previous reports. Most patients with RMDs developed a proper antibody response after COVID-19, particularly if they had symptomatic disease.We acknowledge the generous sharing of the expression constructs by Dr. Florian Krammer, Icahn School of Medicine at Mount Sinai, New York, USA [Development of SARS-CoV-2 reagents was partially supported by the NIAID Centers of Excellence for Influenza Research and Surveillance (CEIRS) contract HHSN272201400008C] and the protein production by Drs. Paula Alves and Rute Castro at Instituto de Biologia Experimental e Tecnológica (iBET) Oeiras, Portugal as part of the Serology COVID consortium.info:eu-repo/semantics/publishedVersio

The CIP2A–TOPBP1 axis safeguards chromosome stability and is a synthetic lethal target for BRCA-mutated cancer

BRCA1/2-mutated cancer cells adapt to the genome instability caused by their deficiency in homologous recombination (HR). Identification of these adaptive mechanisms may provide therapeutic strategies to target tumors caused by the loss of these genes. In the present study, we report genome-scale CRISPR-Cas9 synthetic lethality screens in isogenic pairs of BRCA1- and BRCA2-deficient cells and identify CIP2A as an essential gene in BRCA1- and BRCA2-mutated cells. CIP2A is cytoplasmic in interphase but, in mitosis, accumulates at DNA lesions as part of a complex with TOPBP1, a multifunctional genome stability factor. Unlike PARP inhibition, CIP2A deficiency does not cause accumulation of replication-associated DNA lesions that require HR for their repair. In BRCA-deficient cells, the CIP2A-TOPBP1 complex prevents lethal mis-segregation of acentric chromosomes that arises from impaired DNA synthesis. Finally, physical disruption of the CIP2A-TOPBP1 complex is highly deleterious in BRCA-deficient tumors, indicating that CIP2A represents an attractive synthetic lethal therapeutic target for BRCA1- and BRCA2-mutated cancers

Cluster Analysis Identifies Distinct Patterns of T-Cell and Humoral Immune Responses Evolution Following a Third Dose of SARS-CoV-2 Vaccine in People Living with HIV.

peer reviewed(1) Background: Many vaccines require higher, additional doses or adjuvants to provide adequate protection for people living with HIV (PLWH). Despite their potential risk of severe coronavirus disease 2019, immunological data remain sparse, and a clear consensus for the best booster strategy is lacking. (2) Methods: Using the data obtained from our previous study assessing prospective T-cell and humoral immune responses before and after administration of a third dose of SARS-CoV-2 vaccine, we assessed the correlations between immune parameters reflecting humoral and cellular immune responses. We further aimed at identifying distinct clusters of patients with similar patterns of immune response evolution to determine how these relate to demographic and clinical factors. (3) Results: Among 80 PLWH and 51 healthcare workers (HCWs) enrolled in the study, cluster analysis identified four distinct patterns of evolution characterised by specific immune patterns and clinical factors. We observed that immune responses appeared to be less robust in cluster A, whose individuals were mostly PLWH who had never been infected with SARS-CoV-2. Cluster C, whose individuals showed a particularly drastic increase in markers of humoral immune response following the third dose of vaccine, was mainly composed of female participants who experienced SARS-CoV-2. Regarding the correlation study, although we observed a strong positive correlation between markers mirroring humoral immune response, markers of T-cell response following vaccination correlated only in a lesser extent with markers of humoral immunity. This suggests that neutralising antibody titers alone are not always a reliable reflection of the magnitude of the whole immune response. (4) Conclusions: Our findings show heterogeneity in immune responses among SARS-CoV-2 vaccinated PLWH. Specific subgroups could therefore benefit from distinct immunization strategies. Prior or breakthrough natural infection enhances the activity of vaccines and must be taken into account for informing global vaccine strategies among PLWH, even those with a viro-immunologically controlled infection

Mener un projet international

Internet, construction européenne, mondialisation… : notre horizon ne s'arrête plus à nos frontières. Du jumelage à la coopération décentralisée, les municipalités demandent à leurs services de participer à des projets à dimension internationale. Processus de Bologne, formation tout au long de la vie, internationalisation des études, les universités font elles aussi appel à leurs services pour les accompagner dans ces évolutions. C'est dans ce contexte que s'inscrit ce volume, avec l'ambition de fournir à tous les professionnels des bibliothèques des clés de compréhension de ces nouveaux enjeux ainsi que des exemples concrets d'actions de coopération soutenus par des apports méthodologiques. Comment travailler et partager avec des partenaires étrangers ? Quelles sont les étapes fondamentales d'une coopération : de la convention à l'évaluation ? Qui sont nos relais en France et à l'étranger pour de tels projets ? C'est à travers ces questions que s'organise l'ouvrage, en proposant des éléments de préparation pratiques pour mener ces actions internationales et les pérenniser. Coordonné par Raphaëlle Bats, conservateur chargée des relations internationales à l'enssib, et écrit par différents acteurs du terrain, l'ouvrage traite également de la mobilité des professionnels et des voyages d'étude, du bibliothécaire-formateur ou expert, d'action culturelle et de politique documentaire (du don des documents à l'avenir du patrimoine en Europe en passant par la lecture pour les enfants)

Multisensorische Erfahrung als Zeitzeugnis: Zeugenberichte zu performativ-partizipativer Kunst mit Lebensmitteln - ein Praxisbericht

Wir sind Nathalie Noorlander und Celia Sidler, Künstlerinnen und verfolgen als Celia & Nathalie Sidler eine gemeinsame Kunstpraxis. Aktuell arbeiten wir als wissenschaftliche Projektmitarbeiterinnen im genannten Forschungsprojekt. Bruna Casagrande, Konservatorin-Restauratorin und ebenfalls wissenschaftliche Projektmitarbeiterin wäre eigentlich bei der Präsentation auch mit dabei, aufgrund Krankheit kann sie heute leider nicht anwesend sein. Wir versuchen sie so gut wie möglich zu vertreten. Das vom SNF finanzierte Forschungsprojekt ist an der Hochschule der Künste Bern, am Institut Praktiken und Theorien der Künste angesiedelt. Geleitet wird es von der Kunsthistorikerin Fabiana Senkpiel. Es untersucht erstmals die Dokumentation, Analyse und Rezeption von künstlerischen Arbeiten der Gegenwart, die Lebensmittel als Kunstmaterial verwenden. Solche Arbeiten verweisen, gleichermassen wie Performance-Kunst über ihre Zeitgebundenheit auf die eigene Vergänglichkeit hinweist, auf ihre Kurzlebigkeit: Ihre Materialität ist instabil und unterliegt offensichtlichen Veränderungsprozessen. Ausserdem zeichnen sich solche Werke durch eine multisensorische Dimension aus – neben dem Gesichtssinn werden auch die anderen Sinne der Betrachtenden involviert, wie Riechen, Tasten, Hören und Schmecken. Unser Beitrag präsentiert anhand eines Praxisberichts über gemeinsam durchgeführte Experimente die Zusammenarbeit von Konservierung-Restaurierung und Kunst. Dabei handelt es sich um die Umsetzung zweier Arbeiten von uns und deren konservatorische Dokumentation mittels multiperspektivischem Zeugenbericht, wodurch wir Möglichkeiten und Herausforderungen sowohl für die Dokumentation von ereignishaften künstlerischen Arbeiten als auch hinsichtlich forschender künstlerischer Praxis untersucht haben. Der Fokus unserer Präsentation liegt dabei auf der Verhandlung folgender vier Fragen: • Inwiefern eignet sich der multiperspektivische Zeugenbericht, um die multisensorische Dimension von ereignishaften Kunstwerken festzuhalten? • Welches ist der Status der entstandenen Dokumente - für die konservatorische Dokumentation und für die künstlerische Dokumentation? • Welche Nutzungsmöglichkeiten bieten Zeugenberichte den Künstlerinnen in Hinblick auf künstlerische Forschung? • Wo liegen Möglichkeiten und Herausforderungen bei der Zusammenarbeit von Künstler*innen und Konservator*innen? Im Folgenden werde ich Ihnen die konservatorische Dokumentationsmethode “multiperspektivische Zeugenbericht” vorstellen und anschliessend ihre Anwendung anhand zweier Arbeiten von uns erläutern

Cooperation of oncogenes in cell transformation and sensitization to killing by the parvovirus minute virus of mice

The established line of normal Fisher rat fibroblasts (FR3T3) is naturally resistant to the parvovirus minute virus of mice (MVM), and was used as a model system to study the influence of stepwise transformation on the susceptibility of cells to this virus. When transformed with genes encoding the class I nuclear oncoproteins large T antigen of polyomavirus (PyLT) or v-myc, cells retained a normal appearance, but acquired some ability to form colonies in soft agar. On the other hand, the class II transforming oncogenes encoding the middle T antigen of polyomavirus (PyMT) and c-Ha-ras-1 induced both morphological alterations and a high capacity for anchorage-independent growth in transfected cells. The concomitant expression of oncogenes from both classes (PyLT+PyMT; v-myc+c-Ha-ras-1) induced a supertransformed phenotype characterized by the piling-up of cells into poorly adherent foci, even in low density cultures. The progressive transformation of this cellular system was found to coincide with a gradual increase in its susceptibility to MVMp (MVM prototype strain) infection. Compared to parental cells, class I, class II and double transformants proved to be sensitized to killing by MVMp to a low, moderate and large extent, respectively. Thus, oncogenes from different functional classes appeared to cooperate in the responsiveness of cells to parvovirus attack. Interestingly, this cooperation exacerbated both the killing of infected cells and their capacity to produce viral non-structural (NS) proteins, in agreement with the reported cytotoxic activity of NS polypeptides. Therefore, in this system, parameters of the parvovirus life cycle may serve as indications of the overall progression of the transformation process.SCOPUS: ar.jinfo:eu-repo/semantics/publishe