Syncytia Formation Promotes Virus Resistance to Interferon and Neutralizing Antibodies (preprint)

SARS-CoV-2, like many viruses, generates syncytia. Using SARS-CoV-2 and S (S) expressing recombinant vesicular stomatitis and influenza A viruses, we show that S-mediated syncytia formation provides resistance to interferons in cultured cells, human small airway-derived air-liquid interface cultures and hACE2 transgenic mice. Amino acid substitutions that modulate fusogenicity in Delta- and Omicron-derived S have parallel effects on viral interferon resistance. Syncytia formation also decreases antibody virus neutralization activity in cultured cells. These findings explain the continued selection of fusogenic variants during SARS-CoV-2 evolution in humans and, more generally, the evolution of fusogenic viruses despite the adverse effects of syncytia formation on viral replication in the absence of innate or adaptive immune pressure.

A pattern-centered analysis of adolescents' concerns and hopes about future crises: Differences in ways of coping and personal adjustment.

INTRODUCTION: Many adolescents are concerned about global and future crises, such as the health of the planet or terrorism/safety. Yet, adolescents can also express hope about the future. Thus, asking adolescents about their concern and hope could yield subgroups with different ways of coping and personal adjustment. METHOD: Australian adolescents (N = 863; age 10-16) completed surveys to report their concern (worry and anger) and hope about the planet, safety, jobs, income, housing, and technology, as well as their active and avoidant coping, depression, and life satisfaction. RESULTS: Four distinct subgroups were identified using cluster analysis: Hopeful (low on concern and high on hope across all issues, 32%), Uninvolved (low in concern and hope; 26%), Concerned about the Planet (CP, 27%), and Concerned about Future Life (CFL, 15%). When compared (adjusting for age, sex, and COVID timing), the CP subgroup was highest in active coping (e.g., taking action) but moderate in personal adjustment. Hopeful had the most positive adjustment, whereas CFL had the poorest adjustment. Uninvolved were lowest in coping but moderate in adjustment. CONCLUSIONS: Findings suggest ways of coping and adjustment may not always align, in that CP is connected with more active coping but also some cost to personal adjustment, whereas Hopeful is associated with optimal adjustment but perhaps at the cost of active coping. In addition, although CFL adolescents emerged as the at-risk group, the low levels of hope and coping in Uninvolved adolescents raise the possibility that they are at risk of future problems.

Dynamics of Industrial Electricity Demand in the State of Bahia (Brazil): Evolution of Price and Income and COVID-19 Implications

The growth in demand for electricity is a determining factor for the regional development. This research aimed to estimate the price and income elasticity parameters of the industrial demand for electricity in the State of Bahia, Brazil, from January 2003 to June 2022, in addition to making forecasts for the period from July to December 2022. After verifying that some of the analyzed data were non-stationary, we chose to use the cointegration method, estimating the econometric model through the Error Correction Mechanism (ECM). The ECM considers the model's variables and their lags, relating the series' short and long-run trends. The estimated parameters were inelastic and presented the following values: 0.501 and 0.762 (price and income, long-run) and 0.482 and 0.702 (price and income, short-run). The adjustment coefficient between the short and long-run was also statistically significant and indicated that approximately 8% of the difference between the effective value and the long-run value (balance value) is corrected in each period, demonstrating the rigidity of the consumption structure of electricity in the industrial sector in Bahia. The model also demonstrated an 8.1% reduction in consumption during COVID-19 incidence period. Regarding the forecasts, they proved to be robust and with an average difference of 5.4% in relation to what actually happened in the months of July and August 2022. Thus, the calculated parameters are configured as another source of information for public policymakers and private investors interested in the electricity sector in the State of Bahia.

Rapalogs downmodulate intrinsic immunity and promote cell entry of SARS-CoV-2.

SARS-CoV-2 infection in immunocompromised individuals is associated with prolonged virus shedding and evolution of viral variants. Rapamycin and its analogs (rapalogs, including everolimus, temsirolimus, and ridaforolimus) are FDA-approved as mTOR inhibitors for the treatment of human diseases, including cancer and autoimmunity. Rapalog use is commonly associated with increased susceptibility to infection, which has been traditionally explained by impaired adaptive immunity. Here, we show that exposure to rapalogs increases susceptibility to SARS-CoV-2 infection in tissue culture and in immunologically naive rodents by antagonizing the cell-intrinsic immune response. By identifying one rapalog (ridaforolimus) that is less potent in this regard, we demonstrate that rapalogs promote Spike-mediated entry into cells by triggering the degradation of antiviral proteins IFITM2 and IFITM3 via an endolysosomal remodeling program called microautophagy. Rapalogs that increase virus entry inhibit the mTOR-mediated phosphorylation of the transcription factor TFEB, which facilitates its nuclear translocation and triggers microautophagy. In rodent models of infection, injection of rapamycin prior to and after virus exposure resulted in elevated SARS-CoV-2 replication and exacerbated viral disease, while ridaforolimus had milder effects. Overall, our findings indicate that preexisting use of certain rapalogs may elevate host susceptibility to SARS-CoV-2 infection and disease by activating lysosome-mediated suppression of intrinsic immunity.

Application of Mixed Reality (MR) Based Remote Assistance for Disposition & Resolution on Critical Nonconformance (NC) for Aircraft Production System during Covid or Post Covid Work Environment

Currently, the Aviation industry uses traditional methods of communication, coordination, & human interaction to give disposition to resolve any kind of nonconformance occurrences which occur during manufacturing or operation of commercial or defense products. This involves increased in-person interaction and additional travel, especially to address the nonconformance issues arising at supplier plants or airports around the globe. During Covid and post-Covid environments, human interactions for the transfer of detailed information at different & distant manufacturing plant locations has been difficult, since support engineering teams (Example: Liaison, Product Review, Quality, Supplier Quality, and Manufacturing Engineering, and/or Service Engineering) have been working remotely. Thus, it has been challenging to coordinate with support engineers to get correct dispositions in short timeframes with no additional cost of quality, thereby creating non-value-added time which delayed the release & execution of the respective rework orders. Mixed Reality (MR) based remote assistance can enable delivery of large amount of complex information, knowledge in a cost-effective way. It helps to simulate and visualize various nonconformance scenarios faced in manufacturing unit which can be viewed and worked on without geographic boundaries. Thus, the members of the Engineering, Operations, and Quality team can unite under one platform to gain a better understanding of the nonconformance issue and deliver more informed decision. This quick decision making not only reduces manufacturing lead time and cost of quality for respective plants but also optimizes product delivery and shipment time of the overall supply chain and reduction of Aircraft on Ground (AOG) time for aircraft in service. In this work, we will demonstrate benefits and applications of MR based remote assistance with various cases which will help in taking accurate, realistic dispositions & enable resolutions on any nonconformance resulting in optimized cost of quality in minimum timeframe © 2022 Boeing.

Designing for Resilience: How Dutch Maternity Care Collaborations Anticipate, Adapt, and Thrive during a Pandemic

The success factors and challenges of interorganizational collaboration have been widely studied from different disciplinary perspectives. However, the role of design in making such collaborations resilient has received little attention, although deliberately designing for resilience is likely to be vital to the success of any interorganizational collaboration. This study explores the resilience of interorganizational collaboration by means of a comparative case study of Dutch maternity care providers, which have been facing major challenges due to financial cutbacks, government-enforced collaborative structures, and the recent COVID-19 pandemic. Our findings make two contributions to the literature. First, we further develop the construct of interorganizational resilience. Second, we shed light on how well-designed distributed decision-making enhances resilience, thereby making a first attempt at meeting the challenge of designing for interorganizational resilience.

Cholesterol Binds the Amphipathic Helix of IFITM3 and Regulates Antiviral Activity.

The interferon-induced transmembrane (IFITM) proteins broadly inhibit the entry of diverse pathogenic viruses, including Influenza A virus (IAV), Zika virus, HIV-1, and SARS coronaviruses by inhibiting virus-cell membrane fusion. IFITM3 was previously shown to disrupt cholesterol trafficking, but the functional relationship between IFITM3 and cholesterol remains unclear. We previously showed that inhibition of IAV entry by IFITM3 is associated with its ability to promote cellular membrane rigidity, and these activities are functionally linked by a shared requirement for the amphipathic helix (AH) found in the intramembrane domain (IMD) of IFITM3. Furthermore, it has been shown that the AH of IFITM3 alters lipid membranes in vitro in a cholesterol-dependent manner. Therefore, we aimed to elucidate the relationship between IFITM3 and cholesterol in more detail. Using a fluorescence-based in vitro binding assay, we found that a peptide derived from the AH of IFITM3 directly interacted with the cholesterol analog, NBD-cholesterol, while other regions of the IFITM3 IMD did not, and native cholesterol competed with this interaction. In addition, recombinant full-length IFITM3 protein also exhibited NBD-cholesterol binding activity. Importantly, previously characterized mutations within the AH of IFITM3 that strongly inhibit antiviral function (F63Q and F67Q) disrupted AH structure in solution, inhibited cholesterol binding in vitro, and restricted bilayer insertion in silico. Our data suggest that direct interactions with cholesterol may contribute to the inhibition of membrane fusion pore formation by IFITM3. These findings may facilitate the design of therapeutic peptides for use in broad-spectrum antiviral therapy.

Tropism of SARS-CoV-2 for human cortical astrocytes.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects a variety of cell types impacting the function of vital organ systems, with particularly severe impact on respiratory function. Neurological symptoms, which range in severity, accompany as many as one-third of COVID-19 cases, indicating a potential vulnerability of neural cell types. To assess whether human cortical cells can be directly infected by SARS-CoV-2, we utilized stem-cell-derived cortical organoids as well as primary human cortical tissue, both from developmental and adult stages. We find significant and predominant infection in cortical astrocytes in both primary tissue and organoid cultures, with minimal infection of other cortical populations. Infected and bystander astrocytes have a corresponding increase in inflammatory gene expression, reactivity characteristics, increased cytokine and growth factor signaling, and cellular stress. Although human cortical cells, particularly astrocytes, have no observable ACE2 expression, we find high levels of coronavirus coreceptors in infected astrocytes, including CD147 and DPP4. Decreasing coreceptor abundance and activity reduces overall infection rate, and increasing expression is sufficient to promote infection. Thus, we find tropism of SARS-CoV-2 for human astrocytes resulting in inflammatory gliosis-type injury that is dependent on coronavirus coreceptors.

The moderating and mediating roles of mindfulness and rumination on COVID-19 stress and depression: A longitudinal study of young adults.

The COVID-19 pandemic has not only accounted for a substantial number of deaths in the United States but also deleterious mental health outcomes. We integrated multiple lines of previous research to better understand psychological strengths and difficulties in the face of the pandemic by testing a moderated mediation model that posited that rumination mediates the relationship between COVID-related stress and depression, and mindfulness moderates the relationship between COVID-related stress and rumination. The participants were 196 young adults (79.6% female, 53.1% persons of color), who ranged in age between 18 and 33 years (M = 21.21; SD = 3.62). The participants completed measures of COVID-19 stress, rumination, mindfulness, and depressive symptoms at four time points spanning 1 month. Cross-sectional moderated mediation analysis of the data showed that COVID-related stress predicted rumination, which in turn, predicted depressive symptoms. In addition, mindfulness buffered the relationship between COVID-related stress and rumination. Later, we ran exploratory analyses to examine the robustness of the main models at each wave, linear mixed-effects models to investigate change over time, and conducted a cross-lagged model to test for directional effects. Notably, the longitudinal findings suggested that COVID-related stress and rumination tended to decrease over time and mindfulness remained temporally stable. Additionally, increases in rumination predicted increases in depression. Some longitudinal findings did not consistently congrue with cross-sectional results. Overall, the findings highlight the diverse ways in which individuals cope with stress and the promise of mindfulness as a protective factor against the negative effects of pandemic-related stressors. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Levels and Correlates of Objectively Measured Sedentary Behavior in Young Children: SUNRISE Study Results from 19 Countries.

PURPOSE: There is a paucity of global data on sedentary behavior during early childhood. The purpose of this study was to examine how device-measured sedentary behavior in young children differed across geographically, economically, and sociodemographically diverse populations, in an international sample. METHODS: This multinational, cross-sectional study included data from 1071 children 3-5 yr old from 19 countries, collected between 2018 and 2020 (pre-COVID). Sedentary behavior was measured for three consecutive days using activPAL accelerometers. Sedentary time, sedentary fragmentation, and seated transport duration were calculated. Linear mixed models were used to examine the differences in sedentary behavior variables between sex, country-level income groups, urban/rural settings, and population density. RESULTS: Children spent 56% (7.4 h) of their waking time sedentary. The longest average bout duration was 81.1 ± 45.4 min, and an average of 61.1 ± 50.1 min·d-1 was spent in seated transport. Children from upper-middle-income and high-income countries spent a greater proportion of the day sedentary, accrued more sedentary bouts, had shorter breaks between sedentary bouts, and spent significantly more time in seated transport, compared with children from low-income and lower-middle-income countries. Sex and urban/rural residential setting were not associated with any outcomes. Higher population density was associated with several higher sedentary behavior measures. CONCLUSIONS: These data advance our understanding of young children's sedentary behavior patterns globally. Country income levels and population density appear to be stronger drivers of the observed differences, than sex or rural/urban residential setting.

Daily Associations of Air Pollution and Pediatric Asthma Risk Using the Biomedical REAI-Time Health Evaluation (BREATHE) Kit.

BACKGROUND: Exposure to air pollution is associated with acute pediatric asthma exacerbations, including reduced lung function, rescue medication usage, and increased symptoms; however, most studies are limited in investigating longitudinal changes in these acute effects. This study aims to investigate the effects of daily air pollution exposure on acute pediatric asthma exacerbation risk using a repeated-measures design. METHODS: We conducted a panel study of 40 children aged 8-16 years with moderate-to-severe asthma. We deployed the Biomedical REAI-Time Health Evaluation (BREATHE) Kit developed in the Los Angeles PRISMS Center to continuously monitor personal exposure to particulate matter of aerodynamic diameter < 2.5 µm (PM2.5), relative humidity and temperature, geolocation (GPS), and asthma outcomes including lung function, medication use, and symptoms for 14 days. Hourly ambient (PM2.5, nitrogen dioxide (NO2), ozone (O3)) and traffic-related (nitrogen oxides (NOx) and PM2.5) air pollution exposures were modeled based on location. We used mixed-effects models to examine the association of same day and lagged (up to 2 days) exposures with daily changes in % predicted forced expiratory volume in 1 s (FEV1) and % predicted peak expiratory flow (PEF), count of rescue inhaler puffs, and symptoms. RESULTS: Participants were on average 12.0 years old (range: 8.4-16.8) with mean (SD) morning %predicted FEV1 of 67.9% (17.3%) and PEF of 69.1% (18.4%) and 1.4 (3.5) puffs per day of rescue inhaler use. Participants reported chest tightness, wheeze, trouble breathing, and cough symptoms on 36.4%, 17.5%, 32.3%, and 42.9%, respectively (n = 217 person-days). One SD increase in previous day O3 exposure was associated with reduced morning (beta [95% CI]: -4.11 [-6.86, -1.36]), evening (-2.65 [-5.19, -0.10]) and daily average %predicted FEV1 (-3.45 [-6.42, -0.47]). Daily (lag 0) exposure to traffic-related PM2.5 exposure was associated with reduced morning %predicted PEF (-3.97 [-7.69, -0.26]) and greater odds of "feeling scared of trouble breathing" symptom (odds ratio [95% CI]: 1.83 [1.03, 3.24]). Exposure to ambient O3, NOx, and NO was significantly associated with increased rescue inhaler use (rate ratio [95% CI]: O3 1.52 [1.02, 2.27], NOx 1.61 [1.23, 2.11], NO 1.80 [1.37, 2.35]). CONCLUSIONS: We found significant associations of air pollution exposure with lung function, rescue inhaler use, and "feeling scared of trouble breathing." Our study demonstrates the potential of informatics and wearable sensor technologies at collecting highly resolved, contextual, and personal exposure data for understanding acute pediatric asthma triggers.

The COVID-19 pandemic in older people

Summary The incidence, severity, and mortality of COVID-19 infection appear to impact the elderly more negatively, especially in those who are frail and have multiple comorbidities. This chapter reviews the epidemiology of the COVID-19 pandemic with a focus on the older age group. The transmission of the virus to humans likely occurs through the consumption of an infected animal as a source of food, followed by human-to-human transmission through close contact. The epidemiology of COVID-19 incidence, severity of illness, and mortality appear to have unfavourable outcomes for older people. Managing older people with COVID-19 infection includes symptomatic therapy that focuses on the direct relief of the typical symptoms of COVID-19, drug therapy that focuses on agents directly treating the viral infection load, and general supportive care, which focuses on the relief of atypical symptoms in the acute setting. Ethical issue is the participation of older people in clinical trials.;Objective While endothelial dysfunction has been implicated in the widespread thrombo-inflammatory complications of coronavirus disease-19 (COVID-19), the upstream mediators of endotheliopathy remain for the most part cryptic. Our aim was to identify circulating factors contributing to endothelial cell activation and dysfunction in COVID-19. Methods Human endothelial cells were cultured in the presence of serum or plasma from 244 patients hospitalized with COVID-19 and plasma from 100 patients with non-COVID sepsis. Cell adhesion molecules (E-selectin, VCAM-1, and ICAM-1) were quantified by in-cell ELISA. Results Serum and plasma from patients with COVID-19 increased surface expression of cell adhesion molecules. Furthermore, levels of soluble ICAM-1 and E-selectin were elevated in patient serum and tracked with disease severity. The presence of circulating antiphospholipid antibodies was a strong marker of the ability of COVID-19 serum to activate endothelium. Depletion of total IgG from antiphospholipid antibody-positive serum markedly restrained upregulation of cell adhesion molecules. Conversely, supplementation of control serum with patient IgG was sufficient to trigger endothelial activation. Conclusion These data are the first to suggest that some patients with COVID-19 have potentially diverse antibodies that drive endotheliopathy, adding important context regarding thrombo-inflammatory effects of autoantibodies in severe COVID-19.

Endothelial Cell-Activating Antibodies in COVID-19.

OBJECTIVE: While endothelial dysfunction has been implicated in the widespread thromboinflammatory complications of COVID-19, the upstream mediators of endotheliopathy remain, for the most part, unknown. This study was undertaken to identify circulating factors contributing to endothelial cell activation and dysfunction in COVID-19. METHODS: Human endothelial cells were cultured in the presence of serum or plasma from 244 patients hospitalized with COVID-19 and plasma from 100 patients with non-COVID-19-related sepsis. Cell adhesion molecules (E-selectin, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1 [ICAM-1]) were quantified using in-cell enzyme-linked immunosorbent assay. RESULTS: Serum and plasma from COVID-19 patients increased surface expression of cell adhesion molecules. Furthermore, levels of soluble ICAM-1 and E-selectin were elevated in patient serum and correlated with disease severity. The presence of circulating antiphospholipid antibodies was a strong marker of the ability of COVID-19 serum to activate endothelium. Depletion of total IgG from antiphospholipid antibody-positive serum markedly reduced the up-regulation of cell adhesion molecules. Conversely, supplementation of control serum with patient IgG was sufficient to trigger endothelial activation. CONCLUSION: These data are the first to indicate that some COVID-19 patients have potentially diverse antibodies that drive endotheliopathy, providing important context regarding thromboinflammatory effects of autoantibodies in severe COVID-19.

International COVID-19 mortality forecast visualization: covidcompare.io.

COVID-19 mortality forecasting models provide critical information about the trajectory of the pandemic, which is used by policymakers and public health officials to guide decision-making. However, thousands of published COVID-19 mortality forecasts now exist, many with their own unique methods, assumptions, format, and visualization. As a result, it is difficult to compare models and understand under which circumstances a model performs best. Here, we describe the construction and usability of covidcompare.io, a web tool built to compare numerous forecasts and offer insight into how each has performed over the course of the pandemic. From its launch in December 2020 to June 2021, we have seen 4600 unique visitors from 85 countries. A study conducted with public health professionals showed high usability overall as formally assessed using a Post-Study System Usability Questionnaire. We find that covidcompare.io is an impactful tool for the comparison of international COVID-19 mortality forecasting models.

Oncologists' reflections on patient rights and access to compassionate use drugs: A qualitative interview study from an academic cancer center.

The U.S. Food and Drug Administration (FDA) allows patients with serious illnesses to access investigational drugs for "compassionate use" outside of clinical trials through expanded access (EA) Programs. The federal Right-to-Try Act created an additional pathway for non-trial access to experimental drugs without institutional review board or FDA approval. This removal of oversight amplifies the responsibility of physicians, but little is known about the role of practicing physicians in non-trial access to investigational drugs. We undertook semi-structured interviews to capture the experiences and opinions of 21 oncologists all with previous EA experience at a major cancer center. We found five main themes. Participants with greater EA experience reported less difficulty accessing drugs through the myriad of administrative processes and drug company reluctance to provide investigational products while newcomers reported administrative hurdles. Oncologists outlined several rationales patients offered when seeking investigational drugs, including those with stronger health literacy and a good scientific rationale versus others who remained skeptical of conventional medicine. Participants reported that most patients had realistic expectations while some had unrealistic optimism. Given the diverse reasons patients sought investigational drugs, four factors-scientific rationale, risk-benefit ratio, functional status of the patient, and patient motivation-influenced oncologists' decisions to request compassionate use drugs. Physicians struggled with a "right-to-try" framing of patient access to experimental drugs, noting instead their own responsibility to protect patients' best interest in the uncertain and risky process of off-protocol access. This study highlights the willingness of oncologists at a major cancer center to pursue non-trial access to experimental treatments for patients while also shedding light on the factors they use when considering such treatment. Our data reveal discrepancies between physicians' sense of patients' expectations and their own internal sense of professional obligation to shepherd a safe process for patients at a vulnerable point in their care.

Using mobile phone data to estimate dynamic population changes and improve the understanding of a pandemic: A case study in Andorra (preprint)

Compartmental models are often used to understand and predict the progression of an infectious disease such as COVID-19. The most basic of these models consider the total population of a region to be closed. Many incorporate human mobility into their transmission dynamics, usually based on static and aggregated data. However, mobility can change dramatically during a global pandemic as seen with COVID-19, making static data unsuitable. Recently, large mobility datasets derived from mobile devices have been used, along with COVID-19 infections data, to better understand the relationship between mobility and COVID-19. However, studies to date have relied on data that represent only a fraction of their target populations, and the data from mobile devices have been used for measuring mobility within the study region, without considering changes to the population as people enter and leave the region. This work presents a unique case study in Andorra, with comprehensive datasets that include telecoms data covering 100% of mobile subscribers in the country, and results from a serology testing program that more than 90% of the population voluntarily participated in. We use the telecoms data to both measure mobility within the country and to provide a real-time census of people entering, leaving and remaining in the country. We develop multiple SEIR (compartmental) models parameterized on these metrics and show how dynamic population metrics can improve the models. We find that total daily trips did not have predictive value in the SEIR models while country entrances did. As a secondary contribution of this work, we show how Andorra's serology testing program was likely impacted by people leaving the country. Overall, this case study suggests how using mobile phone data to measure dynamic population changes could improve studies that rely on more commonly used mobility metrics and the overall understanding of a pandemic.

Cross-sectional examination of 24-hour movement behaviours among 3- and 4-year-old children in urban and rural settings in low-income, middle-income and high-income countries: the SUNRISE study protocol.

INTRODUCTION: 24-hour movement behaviours (physical activity, sedentary behaviour and sleep) during the early years are associated with health and developmental outcomes, prompting the WHO to develop Global guidelines for physical activity, sedentary behaviour and sleep for children under 5 years of age. Prevalence data on 24-hour movement behaviours is lacking, particularly in low-income and middle-income countries (LMICs). This paper describes the development of the SUNRISE International Study of Movement Behaviours in the Early Years protocol, designed to address this gap. METHODS AND ANALYSIS: SUNRISE is the first international cross-sectional study that aims to determine the proportion of 3- and 4-year-old children who meet the WHO Global guidelines. The study will assess if proportions differ by gender, urban/rural location and/or socioeconomic status. Executive function, motor skills and adiposity will be assessed and potential correlates of 24-hour movement behaviours examined. Pilot research from 24 countries (14 LMICs) informed the study design and protocol. Data are collected locally by research staff from partnering institutions who are trained throughout the research process. Piloting of all measures to determine protocol acceptability and feasibility was interrupted by COVID-19 but is nearing completion. At the time of publication 41 countries are participating in the SUNRISE study. ETHICS AND DISSEMINATION: The SUNRISE protocol has received ethics approved from the University of Wollongong, Australia, and in each country by the applicable ethics committees. Approval is also sought from any relevant government departments or organisations. The results will inform global efforts to prevent childhood obesity and ensure young children reach their health and developmental potential. Findings on the correlates of movement behaviours can guide future interventions to improve the movement behaviours in culturally specific ways. Study findings will be disseminated via publications, conference presentations and may contribute to the development of local guidelines and public health interventions.

Lessons in self-defence: inhibition of virus entry by intrinsic immunity.

Virus entry, consisting of attachment to and penetration into the host target cell, is the first step of the virus life cycle and is a critical 'do or die' event that governs virus emergence in host populations. Most antiviral vaccines induce neutralizing antibodies that prevent virus entry into cells. However, while the prevention of virus invasion by humoral immunity is well appreciated, considerably less is known about the immune defences present within cells (known as intrinsic immunity) that interfere with virus entry. The interferon-induced transmembrane (IFITM) proteins, known for inhibiting fusion between viral and cellular membranes, were once the only factors known to restrict virus entry. However, the progressive development of genetic and pharmacological screening platforms and the onset of the COVID-19 pandemic have galvanized interest in how viruses infiltrate cells and how cells defend against it. Several host factors with antiviral potential are now implicated in the regulation of virus entry, including cholesterol 25-hydroxylase (CH25H), lymphocyte antigen 6E (LY6E), nuclear receptor co-activator protein 7 (NCOA7), interferon-γ-inducible lysosomal thiol reductase (GILT), CD74 and ARFGAP with dual pleckstrin homology domain-containing protein 2 (ADAP2). This Review summarizes what is known and what remains to be understood about the intrinsic factors that form the first line of defence against virus infection.

Endothelium-protective, histone-neutralizing properties of the polyanionic agent defibrotide.

Neutrophil-mediated activation and injury of the endothelium play roles in the pathogenesis of diverse disease states ranging from autoimmunity to cancer to COVID-19. Neutralization of cationic proteins (such as neutrophil extracellular trap-derived [NET-derived] histones) with polyanionic compounds has been suggested as a potential strategy for protecting the endothelium from such insults. Here, we report that the US Food and Drug Administration-approved polyanionic agent defibrotide (a pleiotropic mixture of oligonucleotides) directly engages histones and thereby blocks their pathological effects on endothelium. In vitro, defibrotide counteracted endothelial cell activation and pyroptosis-mediated cell death, whether triggered by purified NETs or recombinant histone H4. In vivo, defibrotide stabilized the endothelium and protected against histone-accelerated inferior vena cava thrombosis in mice. Mechanistically, defibrotide demonstrated direct and tight binding to histone H4 as detected by both electrophoretic mobility shift assay and surface plasmon resonance. Taken together, these data provide insights into the potential role of polyanionic compounds in protecting the endothelium from thromboinflammation with potential implications for myriad NET- and histone-accelerated disease states.

Opposing activities of IFITM proteins in SARS-CoV-2 infection.

Interferon-induced transmembrane proteins (IFITMs) restrict infections by many viruses, but a subset of IFITMs enhance infections by specific coronaviruses through currently unknown mechanisms. We show that SARS-CoV-2 Spike-pseudotyped virus and genuine SARS-CoV-2 infections are generally restricted by human and mouse IFITM1, IFITM2, and IFITM3, using gain- and loss-of-function approaches. Mechanistically, SARS-CoV-2 restriction occurred independently of IFITM3 S-palmitoylation, indicating a restrictive capacity distinct from reported inhibition of other viruses. In contrast, the IFITM3 amphipathic helix and its amphipathic properties were required for virus restriction. Mutation of residues within the IFITM3 endocytosis-promoting YxxФ motif converted human IFITM3 into an enhancer of SARS-CoV-2 infection, and cell-to-cell fusion assays confirmed the ability of endocytic mutants to enhance Spike-mediated fusion with the plasma membrane. Overexpression of TMPRSS2, which increases plasma membrane fusion versus endosome fusion of SARS-CoV-2, attenuated IFITM3 restriction and converted amphipathic helix mutants into infection enhancers. In sum, we uncover new pro- and anti-viral mechanisms of IFITM3, with clear distinctions drawn between enhancement of viral infection at the plasma membrane and amphipathicity-based mechanisms used for endosomal SARS-CoV-2 restriction.