Biology subjects

Tapparel, C.

Publications and source records attributed to Tapparel, C..

11 recordsLinked to original sources

bioRxiv2026

Human airway organoids as a high-throughput screening platform for antiviral natural products discovery

Antiviral drug discovery for respiratory viruses is hindered by the lack of scalable physiologically relevant systems. Here, we report the first high-throughput screen of 764 natural plant extracts against respiratory syncytial virus (RSV) using human primary airway organoids as a relevant model. A parallel screen conducted in A549 cells allowed the identification of 70 extracts with organoid-specific antiviral activity from which 45 active phytocompounds were purified. We identified early- and late-acting antiviral compounds and demonstrated a polarization-dependent activity for some of them. Collectively, our results establish the use of airway organoids as a scalable first-line platform for high-throughput antiviral discovery and exploit the plant-derived chemical space as an underexplored source of RSV inhibitors.

microbiology↗

bioRxiv2025

Single-cell RNA sequencing identifies progenitor dysfunction, inflammation and premature aging in ex vivo airway epithelium-derived from transplant recipients

Pulmonary dysfunction is a common complication following hematopoietic stem cell transplantation (HSCT) or lung transplantation (LT). Bronchiolitis obliterans syndrome (BOS), an alloimmune complication of transplantation, with complex pathophysiology, contributes substantially to morbidity and mortality in these settings. We aimed to identify common epithelial features predisposing to BOS by comparing epithelia from HSCT and LT without BOS and non-transplant (NT) individuals. We developed an ex vivo model of human airway epithelia (HAE) reconstituted from bronchial biopsies from 6 patients of each group. Using single-cell RNA sequencing, we identified two distinct epithelial profiles among transplant recipients: one resembling NT epithelium and another displaying altered cellular composition and transcriptional signatures across basal, suprabasal, club and submucosal basal duct cells, which were even more pronounced in a patient who subsequently developed BOS. This latter subgroup exhibited dysregulation of epithelial-mesenchymal transition, TNF/NFB signaling and inflammatory pathways, suggesting impaired epithelial function. Moreover, these HAE demonstrated premature epithelial aging and increased expression of genes encoding damage associated molecular patterns. Together, these findings indicate that epithelial abnormalities specific to certain transplant recipients may contribute to BOS development. Although causality cannot yet be definitively established, our data highlight the airway epithelium as a site of sustained post-transplant injury and reveal potential molecular mechanisms underlying BOS pathogenesis.

molecular biology↗

bioRxiv2025

Generation of apical-out nasal organoids to facilitate viral infection and drug screening

Advanced culture systems such as organoids can serve as powerful platforms to study epithelial physiology, as they recapitulate the organisation and many key functions of the tissue of origin. The nasal epithelium is the first respiratory epithelium that is exposed to inhaled airborne pathogens. As a result, it is crucial to model host-pathogen interactions occurring in this tissue. To facilitate the efficient modelling of these interactions, we have developed a method to generate de novo apical-out nasal organoids from nasal epithelial cell aggregates. Optimisation of this method revealed a stark tissue-specific effect of the culture temperature, as apical-out nasal organoids were generated in much higher efficiency at 32.5 {degrees}C, compared to more widely used temperatures of 37{degrees}C. These organoids are composed of ciliated, basal and goblet cells and are produced in a completely standardised and scalable manner, devoid of any extracellular matrix hydrogel. Moreover, they displayed high homogeneity in size and cellular composition, as well as susceptibility to viral infections and capability to model antiviral drug responses. Here, we describe a method for the efficient and reproducible generation of apical-out nasal organoids with high potential to be utilised in host-pathogen interaction studies and personalised medicine from easy-to-access nasal swabs.

cell biology↗

bioRxiv2024

Development of Broad-spectrum β-cyclodextrins-Based Nanomaterials Against Influenza Viruses

In recent decades, epidemics and pandemics have multiplied throughout the world, with viruses generally being the primary agents responsible. Among these, influenza viruses play a key role, as they cause severe respiratory distress, representing a major threat to public health. To enhance the response to viral disease outbreaks, there is a need for ready-to-use broad-spectrum antivirals. We have engineered macromolecules (named CD-SA) consisting of a {beta}-cyclodextrin (CD) scaffold modified with hydrophobic linkers in the primary face, onto which unitary sialic acid (SA) epitopes are covalently grafted, this to mimic influenza virus host receptors. In this study, we demonstrated that CD-SA, with a unitary SA, without extensive polysaccharides or specific connectivity, acts as a potent virucidal antiviral against several variants of human influenza type A and type B viruses. We also assessed the genetic barrier to resistance of CD-SA in vitro and successfully delayed emergence of resistance by combining CD-SA with interferon-{lambda}1 (IFN {lambda}1). Finally, we completed the characterization of the antiviral activity by conducting both ex vivo and in vivo studies, demonstrating a potent antiviral effect in human airway epithelia and in a mouse model of infection, higher than that of Oseltamivir, a currently approved anti-influenza antiviral.

microbiology↗

bioRxiv2024

Enterovirus A71 adaptation to heparan sulfate comes with capsid stability tradeoff

Because of high mutation rates, viruses constantly adapt to new environments. When propagated in cell lines, certain viruses acquire positively charged amino acids on their surface proteins, enabling them to utilize negatively charged heparan sulfate (HS) as an attachment receptor. In this study, we used enterovirus A71 (EV-A71) as model and demonstrated that unlike the parental MP4 variant, the cell-adapted strong HS-binder MP4-97R/167G does not require acidification for uncoating and releases its genome in the neutral or weakly acidic environment of early endosomes. We experimentally confirmed that this pH-independent entry is not associated with the use of HS as an attachment receptor but rather with compromised capsid stability. We then extended these findings to another HS-dependent strain, suggesting that adaptation to HS generally modifies capsid stability and alters entry mechanism. Our data show EV-A71 pH-independent entry for the first time and, more importantly, highlight the intricate interplay between HS-binding, capsid stability, and viral fitness, wherein enhanced multiplication in cell lines leads to attenuation in hostile in vivo environments such as the gastrointestinal tract.

microbiology↗

bioRxiv2022

Trapping virus-loaded aerosols using granular protein nanofibrils and iron oxyhydroxides nanoparticles

The ongoing COVID-19 pandemic has revealed that developing effective therapeutics against viruses might be outpaced by emerging variants,1-5 waning immunity,6-9 vaccine skepticism/hesitancy,10-12 lack of resources,13-16 and the time needed to develop virus-specific therapeutics,17,18 emphasizing the importance of non-pharmaceutical interventions as the first line of defense against virus outbreaks and pandemics.19-23 However, fighting the spread of airborne viruses has proven extremely challenging,23-28 much more if this needs to be achieved on a global scale and in an environmentally-friendly manner.29,30 Here, we introduce an aerosol filter made of granular material based on whey protein nanofibrils and iron oxyhydroxides nanoparticles. The material is environmentally-friendly, biodegradable, and composed mainly of a dairy industry byproduct.31 It features remarkable filtration efficiencies between 95.91% and 99.99% for both enveloped and non-enveloped viruses, including SARS-CoV-2, the influenza A virus strain H1N1, enterovirus 71, bacteriophage {Phi}6, and bacteriophage MS2. The developed material is safe to handle and recycle, with a simple baking step sufficient to inactivate trapped viruses. The high filtration efficiency, virtually-zero environmental impact, and low cost of the material illuminate a viable role in fighting current and future pandemics on a global scale.

microbiology↗

bioRxiv2022

Geneticin shows selective antiviral activity against SARS-CoV-2 by targeting programmed -1 ribosomal frameshifting

SARS-CoV-2 is currently causing an unprecedented pandemic. While vaccines are massively deployed, we still lack effective large-scale antiviral therapies. In the quest for antivirals targeting conserved structures, we focused on molecules able to bind viral RNA secondary structures. Aminoglycosides are a class of antibiotics known to interact with the ribosomal RNA of both prokaryotes and eukaryotes and have previously been shown to exert antiviral activities by interacting with viral RNA. Here we show that the aminoglycoside geneticin is endowed with antiviral activity against all tested variants of SARS-CoV-2, in different cell lines and in a respiratory tissue model at non-toxic concentrations. The mechanism of action is an early inhibition of RNA replication and protein expression related to a decrease in the efficiency of the -1 programmed ribosomal frameshift (PRF) signal of SARS-CoV-2. Using in silico modelling, we have identified a potential binding site of geneticin in the pseudoknot of frameshift RNA motif. Moreover, we have selected, through virtual screening, additional RNA binding compounds, interacting with the same site with increased potency.

microbiology↗

bioRxiv2021

A novel anti-influenza combined therapy assessed by single cell RNA-sequencing

Influenza makes millions of people ill every year, placing a large burden on the healthcare system and the economy. To develop a novel 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. We also showed that each cell type comprises multiple sub-types, whose proportions are altered by H1N1 infection, and assess the ability of the treatments to restore them. To the best of our knowledge this is the first study investigating the effectiveness of an antiviral therapy by transcriptomic studies at the single cell level.

genomics↗

bioRxiv2020

A Nasal Spray Solution of Grapefruit Seed Extract plus Xylitol Displays Virucidal Activity Against SARS-Cov-2 In Vitro

ABSTARCTThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the ongoing pandemic coronavirus disease 2019 (COVID-19) has triggered worldwide concerted efforts in an attempt to identify effective therapies. In the present study, we have identified two candidate agents with potential activity against SARS-CoV-2 which can be administered intranasally, namely, xylitol and grape seed fruit extract (GSE). A commercially available nasal spray (Xlear) combining xylitol and GSE has been available for years, but the antiviral effects of this solution have not been documented. This in vitro study examined the virucidal effect of Xlear against SARS-CoV-2. To this end, two independent sets of experiments were carried out to test the hypothesis that Xlear is an effective (Experiment I) and replicable (Experiment II) means to deactivate SARS-CoV-2. When tested against SARS-CoV-2, the test compound GSE 0.2% was the only compound effective at reducing >3 log10 CCID50 infectious virus from, 3.67 log10 CCID50/0.1 mL to an undetectable amount of infectious virus. The present results validated by two independent sets of experiments, performed by different labs, on different viral strains, provide early evidence to encourage further pilot and clinical studies aimed at investigating the use of Xlear as a potential treatment for COVID-19

cell biology↗

bioRxiv2020

Methylene Blue has a potent antiviral activity against SARS-CoV-2 in the absence of UV-activation in vitro

Methylene blue is an FDA and EMA approved drug with an excellent safety profile. It displays broad-spectrum virucidal activity in the presence of UV light and has been shown to be effective in inactivating various viruses in blood products prior to transfusions. In addition, its use has been validated for methemoglobinemia and malaria treatment. Here we show the virucidal activity of methylene blue at low micromolar concentrations and in the absence of UV activation against SARS-CoV2.

microbiology↗

bioRxiv2020

Non-Toxic Virucidal Macromolecules Show High Efficacy Against Influenza Virus Ex Vivo and In Vivo

Influenza is one of the most widespread viral infections worldwide and represents a major public health problem. The risk that one of the next pandemics is caused by an influenza strain is very high. It is very important to develop broad-spectrum influenza antivirals to be ready for any possible vaccine shortcomings. Anti-influenza drugs are available but they are far from ideal. Arguably, an ideal antiviral should target conserved viral domains and be virucidal, i.e. irreversibly inhibit viral infectivity. Here, we describe a new class of broad-spectrum anti-influenza macromolecules that meets these criteria and displays exceedingly low toxicity. These compounds are based on a cyclodextrin core modified on its primary face with long hydrophobic linkers terminated in 6sialyl-N-acetyllactosamine (6SLN) or 3SLN. SLN enables nanomolar inhibition of the viruses while the hydrophobic linkers confer irreversibility to the inhibition. The combination of these two properties allows for efficacy in vitro against several human or avian influenza strains, as well as against a 2009 pandemic influenza strain ex vivo. Importantly, we show that, in mice, the compounds provide therapeutic efficacy when administered 24h post-infection allowing 90% survival as opposed to no survival for the placebo and oseltamivir..

microbiology↗