Publications by authors named "Constant S"

Pulmonary mucus serves as a crucial protective barrier in the respiratory tract, defending against pathogens and contributing to effective clearance mechanisms. In Muco Obstructive Pulmonary Diseases (MOPD), abnormal rheological properties lead to highly viscous mucus, fostering chronic infections and exacerbations. While prior research has linked mucus viscoelasticity to its mucin content, the variability in MOPD patients implies the involvement of other factors.

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In recent decades, epidemics and pandemics have multiplied throughout the world, with viruses generally being the primary responsible agents. Among these, influenza viruses play a key role, as they potentially cause severe respiratory distress, representing a major threat to public health. Our study aims to develop new broad-spectrum antivirals against influenza to improve the response to viral disease outbreaks.

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The emergence, global spread, and persistence of SARS-CoV-2 resulted in an unprecedented need for effective antiviral drugs. Throughout the pandemic, various drug development and treatment strategies were adopted, including repurposing of antivirals designed for other viruses along with a multitude of other drugs with varying mechanisms of action (MoAs). Furthermore, multidrug treatment against COVID-19 is an ongoing topic and merits further investigation.

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Article Synopsis
  • Standard information reporting is essential for consistent assay conditions and data, enabling easier comparisons between laboratories.
  • The publication presents the Minimum Information for Reporting on the TEER assay (MIRTA), a key method used to assess cell culture models and toxicity potential.
  • Developed through an international collaboration, the recommendations from the RespTox Collaborative aim to improve data transparency, reproducibility, and quality in both respiratory and other cell systems.
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COVID-19 remains a severe condition for many including immunocompromised individuals. There remains a need for effective measures against this and other respiratory infections, which transmit via virus-laden droplets that reach the nasal or oral mucosae. Nasal sprays offer potential protection against viruses.

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The use of fixed dose-combinations of antivirals with different mechanisms of action has proven key in the successful treatment of infections with HIV and HCV. For the treatment of infections with SARS-CoV-2 and possible future epi-/pandemic coronaviruses, it will be important to explore the efficacy of combinations of different drugs, in particular to avoid resistance development, such as in patients with immunodeficiencies. This work explores the effect of a combination of 3 broad-spectrum antiviral nucleosides on the replication of coronaviruses.

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  • * This study investigated CsA's antiviral effects on SARS-CoV-2 variants (Omicron BA.1 and Delta) and human parainfluenza virus 3 (HPIV3), finding it significantly reduced viral load against the Delta variant but had no notable effect on the other viruses.
  • * CsA's mechanism appears complex, influencing inflammatory pathways and specific viral interactions, and highlights the need for further research to understand its effects on viral infections in immunosuppressed patients, pointing out
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Humins, (side-)products of the acid-catalysed dehydration of carbohydrates, will be produced in substantial quantities with the development of industrial biorefining processes. Most structural knowledge about such humins is based on synthetic model humins prepared at lab-scale from typical carbohydrate(-derived) compounds. Here, we report the first extensive characterisation study of an industrial humin.

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Background: Fexofenadine (FEX) is an antihistamine that acts as an inverse agonist against histamine (HIS) receptor 1 (H1R), which mediates the allergic reaction. Inverse agonists may be more potent than neutral antagonists, as they bind the same receptor as the agonist (HIS) but stabilize the inactive form and induce an opposite pharmacological response, suppressing the basal activity of H1R and preventing HIS from binding. This study aims to establish and validate a model of HIS-induced inflammation based on fully reconstituted human nasal epithelial tissue to assess the activity of FEX as an inverse agonist in this model and explore its link to clinical benefit.

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The use of fixed dose-combinations of antivirals with different mechanisms of action has proven a key in the successful treatment of infections with HIV and HCV. For the treatment of infections with SARS-CoV-2 and possible future epi-/pandemic coronaviruses, it will be important to explore the efficacy of combinations of different drugs, in particular to avoid resistance development, such as in patients with immunodeficiencies. As a first effort, we studied the antiviral potency of combinations of antivirals.

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  • * Human Parainfluenza Virus type 3 (HPIV-3) is frequently associated with COPD exacerbations, but its specific effects on the respiratory cells of COPD patients hadn’t been studied before this research.
  • * The study found that COPD-affected respiratory cells showed heightened inflammation and a less effective antiviral response compared to healthy cells, possibly making it harder for the immune system to fight off viral infections and leading to ongoing inflammation.
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In the COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), face masks have become a very important safety measure against the main route of transmission of the virus: droplets and aerosols. Concerns that masks contaminated with SARS-CoV-2 infectious particles could be a risk for self-contamination have emerged early in the pandemic as well as solutions to mitigate this risk. The coating of masks with sodium chloride, an antiviral and non-hazardous to health chemical, could be an option for reusable masks.

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Over the last century, the number of epidemics caused by RNA viruses has increased and the current SARS-CoV-2 pandemic has taught us about the compelling need for ready-to-use broad-spectrum antivirals. In this scenario, natural products stand out as a major historical source of drugs. We analyzed the antiviral effect of 4 stilbene dimers [1 (trans-δ-viniferin); 2 (11',13'-di-O-methyl-trans-δ-viniferin), 3 (11,13-di-O-methyl-trans-δ-viniferin); and 4 (11,13,11',13'-tetra-O-methyl-trans-δ-viniferin)] obtained from plant substrates using chemoenzymatic synthesis against a panel of enveloped viruses.

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Introduction: Rhinovirus (RV) infections constitute one of the main triggers of asthma exacerbations and an important burden in pediatric yard. However, the mechanisms underlying this association remain poorly understood.

Methods: In the present study, we compared infections of reconstituted airway epithelia originating from asthmatic versus healthy donors with representative strains of RV-A major group and minor groups, RV-C, RV-B, and the respiratory enterovirus EV-D68.

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During the coronavirus disease (COVID-19) pandemic, wearing face masks in public spaces became mandatory in most countries. The risk of self-contamination when handling face masks, which was one of the earliest concerns, can be mitigated by adding antiviral coatings to the masks. In the present study, we evaluated the antiviral effectiveness of sodium chloride deposited on a fabric suitable for the manufacturing of reusable cloth masks using techniques adapted to the home environment.

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Influenza makes millions of people ill every year, placing a large burden on the healthcare system and the economy. To develop a treatment against influenza, we combined virucidal sialylated cyclodextrins with interferon lambda and demonstrated, in human airway epithelia, that the two compounds inhibit the replication of a clinical H1N1 strain more efficiently when administered together rather than alone. We investigated the mechanism of action of the combined treatment by single cell RNA-sequencing analysis and found that both the single and combined treatments impair viral replication to different extents across distinct epithelial cell types.

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Article Synopsis
  • Enteroviruses (EVs), highly diverse viruses, can cause various symptoms; EV-D68 (respiratory) and EV-D94 (enteric) illustrate this diversity despite being in the same species.
  • The study utilized 3D tissue culture models to show how temperature affects tissue tropism and identified key differences in how intestinal and respiratory tissues respond to these viruses.
  • Transcriptomic analysis revealed that EV-D68 activates antiviral pathways while EV-D94 minimizes immune responses, highlighting distinct strategies in their interactions with host tissues.
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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with unprecedented economic and societal impact. Currently, several vaccines are available and multitudes of antiviral treatments have been proposed and tested. Although many of the vaccines show clinical efficacy, they are not equally accessible worldwide.

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The nasal epithelium is a key portal for infection by respiratory viruses such as SARS-CoV-2 and represents an important target for prophylactic and therapeutic interventions. In the present study, we test the safety and efficacy of a newly developed nasal spray (AM-301, marketed as Bentrio) against infection by SARS-CoV-2 and its Delta variant on an in vitro 3D-model of the primary human nasal airway epithelium. Safety was assessed in assays for tight junction integrity, cytotoxicity and cilia beating frequency.

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The SARS-CoV-2 virus has infected more than 261 million people and has led to more than 5 million deaths in the past year and a half ( https://www.who.org/ ).

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Iota-carrageenan (IC) nasal spray, a medical device approved for treating respiratory viral infections, has previously been shown to inhibit the ability of a variety of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), to enter and replicate in the cell by interfering with the virus binding to the cell surface. The aim of this study was to further investigate the efficacy and safety of IC in SARS-CoV-2 infection in advanced models of the human respiratory epithelium, the primary target and entry port for SARS-CoV-2. We extended the safety assessment of nebulized IC in a 3-dimensional model of reconstituted human bronchial epithelium, and we demonstrated the efficacy of IC in protecting reconstituted nasal epithelium against viral infection and replication of a patient-derived SARS-CoV-2 strain.

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Experimental systems that faithfully replicate human physiology at cellular, tissue and organ level are crucial to the development of efficacious and safe therapies with high success rates and low cost. The development of such systems is challenging and requires skills, expertise and inputs from a diverse range of experts, such as biologists, physicists, engineers, clinicians and regulatory bodies. Kirkstall Limited, a biotechnology company based in York, UK, organised the annual conference, (ACTC), which brought together people having a variety of expertise and interests, to present and discuss the latest developments in the field of cell and tissue culture and modelling.

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Influenza viruses are a leading cause of morbidity and mortality worldwide. These air-borne pathogens are able to cross the species barrier, leading to regular seasonal epidemics and sporadic pandemics. Influenza viruses also possess a high genetic variability, which allows for the acquisition of resistance mutations to antivirals.

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The ongoing COVID-19 pandemic has highlighted the dearth of approved drugs to treat viral infections, with only ∼90 FDA approved drugs against human viral pathogens. To identify drugs that can block SARS-CoV-2 replication, extensive drug screening to repurpose approved drugs is underway. Here, we screened ∼18,000 drugs for antiviral activity using live virus infection in human respiratory cells.

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SARS-CoV-2 infection causing the COVID-19 pandemic calls for immediate interventions to avoid viral transmission, disease progression, and subsequent excessive inflammation and tissue destruction. Primary normal human bronchial epithelial cells are among the first targets of SARS-CoV-2 infection. Here, we show that ColdZyme medical device mouth spray efficiently protected against virus entry, excessive inflammation, and tissue damage.

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