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Lipid membrane fusion is an essential function in many biological processes. Detailed mechanisms of membrane fusion and the protein structures involved have been mainly studied in eukaryotic systems, whereas very little is known about membrane fusion in prokaryotes. Haloarchaeal pleomorphic viruses (HRPVs) have a membrane envelope decorated with spikes that are presumed to be responsible for host attachment and membrane fusion. Here we determine atomic structures of the ectodomains of the 57-kDa spike protein VP5 from two related HRPVs revealing a previously unreported V-shaped fold. By Volta phase plate cryo-electron tomography we show that VP5 is monomeric on the viral surface, and we establish the orientation of the molecules with respect to the viral membrane. We also show that the viral membrane fuses with the host cytoplasmic membrane in a process mediated by VP5. This sheds light on protein structures involved in prokaryotic membrane fusion., Lipid membrane fusion is an essential function in many biological processes but little is known about membrane fusion in prokaryotes. The authors here study how haloarchaeal pleomorphic viruses (HRPVs) infect archaeal hosts. The structure-function analysis of the spike proteins shed light on prokaryotic membrane fusion.

INTRODUCTION: Antineoplastic drugs (AD) are potentially carcinogenic and/or reprotoxic molecules. Healthcare professionals are increasingly exposed to these drugs and can be potentially contaminated by them. Internal contamination of professionals is a key concern for occupational physicians in the assessment and management of occupational risks in healthcare settings. Objectives of this study are to report AD internal contamination rate in nursing staff and to identify factors associated with internal contamination. METHODS AND ANALYSIS: This trial will be conducted in two French hospital centres: University Hospital of Bordeaux and IUCT-Oncopole of Toulouse. The target population is nurses practicing in one of the fifteen selected care departments where at least one of the five studied AD is handled (5-fluorouracil, cyclophosphamide, doxorubicin, ifosfamide, methotrexate). The trial will be conducted with the following steps: (1) development of analytical methods to quantify AD urine biomarkers, (2) study of the workplace and organization around AD in each care department (transport and handling, professional practices, personal and collective protection equipments available) (3) development of a self-questionnaire detailing professional activities during the day of inclusion, (4) nurses inclusion (urine samples and self-questionnaire collection), (5) urine assays, (6) data analysis. ETHICS AND DISSEMINATION: The study protocol has been approved by the French Advisory Committee on the Treatment of Information in Health Research (CCTIRS) and by the French Data Protection Authority (CNIL). Following the opinion of the Regional Committee for the Protection of Persons, this study is outside the scope of the provisions governing biomedical research and routine care (n degrees 2014/87). The results will be submitted to peer-reviewed journals and reported at suitable national and international meetings. TRIAL REGISTRATION NUMBER: NCT03137641.

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SR146131 inhibited the binding of [125I]-Bolton Hunter (BH)-sulfated cholecystokinin octapeptide (CCK-8S) for the human recombinant cholecystokinin subtype 1 (CCK1) receptor (IC50 = 0.56 nM) with high (300-fold) selectivity to the CCK2 receptor. The biological activity of SR146131 was characterized in vitro in a NIH-3T3 cell line expressing the human recombinant CCK1 receptor (3T3-hCCK1). Measuring intracellular calcium release, SR146131 behaved as a full agonist with an efficacy comparable with that of CCK-8S (EC50 = 1.38 +/- 0.06 nM). On individual cells, SR146131 induced, like CCK-8S, Ca2+ oscillations at subnanomolar concentrations and sustained responses at higher concentrations. Like CCK-8S, SR146131 also fully stimulated inositol monophosphate formation (EC50 = 18 +/- 4 nM). SR146131 partially activated mitogen-activated protein kinase and enhanced the expression of the immediate early gene krox 24. In the human CHP212 and IMR32 neuroblastoma cell lines, which constitutively express the CCK1 receptor, SR146131 behaved as a partial agonist on intracellular calcium release and inositol monophosphate formation. All of these effects of SR146131 were inhibited by the CCK1 receptor antagonists SR27897B and devazepide, suggesting that the effects of SR146131 were entirely mediated by the CCK1 receptor. In contrast, high concentrations (1 microM) of SR146131 had only minimal effects on CCK-8S-stimulated and unstimulated Chinese hamster ovary (CHO) cells expressing the human CCK2 receptor, indicating that SR146131 is functionally inactive on the CCK2 receptor. In conclusion, these in vitro experiments show that SR146131 is a highly potent and selective agonist of the CCK1 receptor.

Guanine quadruplex (G4) structures in the viral genome have a key role in modulating viruses' biological activity. While several DNA G4 structures have been experimentally resolved, RNA G4s are definitely less explored. We report the first calculated G4 structure of the RG-1 RNA sequence of SARS-CoV-2 genome, obtained by using a multiscale approach combining quantum and classical molecular modeling and corroborated by the excellent agreement between the corresponding calculated and experimental circular dichroism spectra. We prove the stability of the RG-1 G4 arrangement as well as its interaction with G4 ligands potentially inhibiting viral protein translation.

We investigated the mechanisms leading to the specific recognition of Guanine Guadruplex (G4) by DARPins peptides, which can lead to the design of G4s specific sensors. To this end we carried out all-atom molecular dynamic simulations to unravel the interactions between specific nucleic acids, including human-telomeric (h-telo), Bcl-2, and c-Myc, with different peptides, forming a DARPin/G4 complex. By comparing the sequences of DARPin with that of a peptide known for its high affinity for c-Myc, we show that the recognition cannot be ascribed to sequence similarity but, instead, depends on the complementarity between the three-dimensional arrangement of the molecular fragments involved: the α-helix/loops domain of DARPin and the G4 backbone. Our results reveal that DARPins tertiary structure presents a charged hollow region in which G4 can be hosted, thus the more complementary the structural shapes, the more stable the interaction.

The STimulator of INterferon Genes (STING) protein is a cornerstone of the human immune response. Its activation by cGAMP upon the presence of cytosolic DNA stimulates the production of type I interferons and inflammatory cytokines which are crucial for protecting cells from infections. STING signaling pathway can also influence both tumor-suppressive and tumor-promoting mechanisms, rendering it an appealing target for drug design. In the human population, several STING variants exist and exhibit dramatic differences in their activity, impacting the efficiency of the host defense against infections. Understanding the differential molecular mechanisms exhibited by these variants is of utmost importance notably towards personalized medicine treatments against diseases such as viral infections (COVID-19, Dengue…), cancers, or auto-inflammatory diseases. Owing to micro-seconds scale molecular modeling simulations and post-processing by contacts analysis and Machine Learning techniques, we reveal the dynamical behavior of four STING variants (wild type, G230A, R293Q, and G230A-R293Q) and we rationalize the variability of efficiency observed experimentally. Our results show that the decrease of STING activity is linked to a stiffening of key-structural features of the binding cavity, together with changes of the interaction patterns within the protein.

Rationale and background For the marketed COVID-19 vaccines, a pan-European cohort event monitoring system is an important addition to existing spontaneous reporting systems for signal detection. This enables the collection of patient-reported safety data in near real-time and generates incidence rates of vaccine-related adverse reactions. Research question and objectives Primary aim To collect data on patient-reported adverse reactions of different COVID-19 vaccines, estimate the frequency, compare incidence rates across the participating countries in general and special populations (pregnant and lactating women, children and adolescents, immunocompromised, people with history of allergy, and people with prior SARS-CoV-2 infection) in near-real-time. Secondary aim To identify and generate incidence rates and potential predictors of the most frequently reported adverse reactions related to different COVID-19 vaccines after first/second dose(s) of the first vaccination cycle as well as booster doses within the general population and special cohorts of vaccinees. Study design Prospective cohort study in general and special populations (pregnant and lactating women, children and adolescents, immunocompromised, people with history of allergy and people with prior SARS- CoV-2 infection). Data are prospectively collected, directly from vaccine recipients in 11 countries. The common core data from different countries were pooled, stratified by special cohort and analysed at the European level. The study is set up as a cohort monitoring for a duration of up until 6 months from the first dose vaccination date (except for pregnant women who are followed up until 1.5 month after the pregnancy end). Data were collected using the Lareb Intensive Monitoring (LIM) system (general population first dose), the Research Online (RO) tool (booster and special populations), the Croat OpeN data collection system and the German SafeVac2.0 data collection system. Setting Participants to be included should be vaccinated in one of the participating countries in the period ranging from December 2020 (in Countries already starting prospective monitoring in ECVM) until August 2022. This interim report includes LIM and RO data updated until the 9th of February 2022, and Croat OPeN data until the 15th of February 2022. German SafeVac 2.0 datasets are included in batches, with Moderna data updated until May 2021, AstraZeneca until September 2021, and the new BioNTech/Pfizer data until March 2022. Subjects and study size General and special population vaccinees (pregnant and lactating women, children, adolescents, immunocompromised, people with a history of allergy, and people with prior SARS-CoV-2 infection) who were recruited at multiple vaccination centers within 48 hours from either the first or booster COVID-19 vaccine dose administration. The aim was the inclusion of up to 60,000 vaccine recipients belonging to both general and special cohorts from 12 European countries which would exceed the numbers of vaccinated in clinical trials. Variables Vaccine brand and batch number, adverse drug reactions (ADRs), age, sex, height and weight, geographical area, medical history including information on comorbidities and concomitant diseases, and concomitant medications. Results The populations that adhere to this observational study are described in this report by the number of patients included in the cohort for each participating country, gender distribution, age categories, and vaccine brands. First vaccination cycle data in general population For both general and special populations, dedicated cumulative structured overviews of numbers and incidences of all adverse reactions are provided. Reported adverse events are stratified in solicited, unsolicited, serious adverse events, adverse events of special interest, vaccine brand, country, gender, and age groups when all these informative details can be extrapolated from the data. For the first vaccination cycle, in this report we included 30,108 participants in Belgium, Croatia, France, Italy, the Netherlands, and the United Kingdom, and 520,076 general population participants from Germany. Across the sites 0.2-0.3% % reported at least one serious adverse reaction after receiving the first and/or the second dose. The majority of all reports of an AESI were from females, across all vaccine brands. Special populations first vaccination Among the 7,057 vaccinees in the special populations who reported at least one ADR following the first vaccination dose, 17 (0.2%) reported at least one serious ADR. In 3,793 vaccinees who reported at least one ADR following the second vaccination dose, 9 (0.2%) reported at least one serious ADR. Out of the total number of vaccinees who reported at least one ADR following the first (N= 7,057) and second (N= 3,793) vaccination dose, 25 (0.4%) and 15 (0.4%) vaccinees reported at least one AESI following the first and second vaccination dose, respectively. The most reported solicited local adverse reaction among all the COVID-19 vaccine brands, special cohorts, and between 1st and 2nd dose is injection site pain. This is in line with the general population observations (and with previously published works). Among the solicited systemic adverse reactions, fatigue, headache, malaise, and myalgia, were the most frequently reported events, which is consistent with total populations. Serious adverse reactions and AESI were uncommon among each of the special cohorts, although sample size and power to detect differs. This is also in line with the general populations' pivotal clinical trials and this study's results in general populations. Caution should be taken in interpreting the data as analysis considering participants’ baseline characteristics and the adverse reaction they reported has not yet been conducted. On the basis of the Research Online app that was used in Italy, Romania, Slovakia, Spain and Switzerland, 377 first dose vaccinees with one of the special conditions were included mostly children and persons with prior Sars-Cov-2 infection. The rate of serious reactions could not yet be validly estimated. Pregnant women: 8 cases of spontaneous abortion events were observed among both general and special population data, but only 1 case was recorded as pregnant women at baseline. No other AESI were yet observed. Children/adolescents: Serious ADRs following COVID-19 vaccination are uncommon. No AESI were observed. Immunocompromised, people with history of allergy, people with prior COVID-19: Serious ADRs and AESI after COVID-19 vaccinations are uncommon. Among the observed AESI, COVID-19 infection, hypersensitivity, and arrhythmia, have been the most frequently reported. Booster dose A total of 11.100 subjects who received a booster dose were included in this study, all use the RO application for enrolment. Most of the persons were not part of a special population (8493), 419 pregnant or lactating women were included. BioNTech/Pfizer and Moderna are the most commonly administered COVID-19 vaccines in our observational study. Children/adolescents reported the lowest rate of ADRs among the cohorts involved in this booster vaccination study. Lactating women reported the highest numbers of ADRs. Informative details about the type of the reported ADRs are not yet reported for these booster dose data. Conclusion This interim report summarises the safety evidence of covid-19 vaccines in more than 550,000 persons from both the general and special populations that were included after first dose, and booster doses. We combined data originating from a total of eleven countries and four different data capture systems. Solicited reactions were comparable to those observed in trials. Across the sites 0.2-0.3% % reported at least one serious adverse reaction after receiving the first and/or the second dose, this was similar after the first booster., The research leading to these results was conducted as part of the activities of the EU PE&PV (Pharmacoepidemiology and Pharmacovigilance) Research Network (led by Utrecht University) with collaboration from the Vaccine Monitoring Collaboration for Europe network (VAC4EU). The project has received support from the European Medicines Agency under the Framework service contract nr EMA/2018/23/PE. This report expresses the opinion of the authors and may not be understood or quoted as being made on behalf of or reflecting the position of the European Medicines Agency or one of its committees or working parties. The work in this report is based on: EU PAS Register No: WP1: EUPAS42504 WP2: EUPAS39798

DNA integrity is an important factor that assures genome stability and, more generally, the viability of cells and organisms. In the presence of DNA damage, the normal cell cycle is perturbed when cells activate their repair processes. Although efficient, the repair system is not always able to ensure complete restoration of gene integrity. In these cases, mutations not only may occur, but the accumulation of lesions can either lead to carcinogenesis or reach a threshold that induces apoptosis and programmed cell death. Among the different types of DNA lesions, strand breaks produced by ionizing radiation are the most toxic due to the inherent difficultly of repair, which may lead to genomic instability. In this article we show, by using classical molecular simulation techniques, that compared to canonical double-helical B-DNA, guanine-quadruplex (G4) arrangements show remarkable structural stability, even in the presence of two strand breaks. Since G4-DNA is recognized for its regulatory roles in cell senescence and gene expression, including oncogenes, this stability may be related to an evolutionary cellular response aimed at minimizing the effects of ionizing radiation.

In the last few years, the sudden outbreak of COVID-19 caused by SARS-CoV-2 proved the crucial importance of understanding how emerging viruses work and proliferate, in order to avoid the repetition of such a dramatic sanitary situation with unprecedented social and economic costs. West Nile Virus is a mosquito-borne pathogen that can spread to humans and induce severe neurological problems. This RNA virus caused recent remarkable outbreaks, notably in Europe, highlighting the need to investigate the molecular mechanisms of its infection process in order to design and propose efficient antivirals. Here, we resort to all-atom Molecular Dynamics simulations to characterize the structure of the 5′-untranslated region of the West Nile Virus genome and its specific recognition by the human innate immune system via oligoadenylate synthetase. Our simulations allowed us to map the interaction network between the viral RNA and the host protein, which drives its specific recognition and triggers the host immune response. These results may provide fundamental knowledge that can assist further antivirals’ design, including therapeutic RNA strategies.