Biology subjects

Cagno, V.

Publications and source records attributed to Cagno, V..

7 recordsLinked to original sources

bioRxiv2025

A pan-respiratory virus attachment inhibitor with high potency in human airway models and in vivo

Respiratory viruses can cause severe infections, including bronchiolitis and pneumonia, often leading to hospitalization or death. Due to their ease of transmission, they are also scrutinized for their pandemic potential. No broad-spectrum antiviral is currently available. However most respiratory viruses use sialic acid or heparan sulfates as attachment receptors. Here, we report the identification of a pan-respiratory antiviral strategy based on mimicking both glycans. We synthesized and characterized a unique modified cyclodextrin that simultaneously mimics heparan sulfate and sialic acid. This novel compound demonstrated broad-spectrum antiviral activity against important human pathogens: parainfluenza virus 3, respiratory syncytial virus, influenza virus H1N1, SARS-CoV-2. Additionally, the compound is active against different avian strains of influenza virus, revealing its importance for pandemic preparedness. The compound retains broad- spectrum activity in ex vivo models of respiratory tissues and in vivo experiments against RSV and Influenza virus, using both prophylactic and therapeutic strategies. These findings represent a significant step forward in the development of future treatments and preventive measures for respiratory viral infections. Significance StatementFollowing the SARS-CoV-2 pandemic, Influenza A H5N1 has become widespread in poultry and has already begun to spill over into mammals, posing a potential risk for the next pandemic. Indeed, respiratory viruses represent a major threat for future global health crises. Unfortunately, there is a significant lack of broad-spectrum antivirals available for such scenarios. To address this gap, our study developed a single molecule with the capacity to inhibit a wide range of clinically relevant human respiratory viruses including avian strains of influenza virus. This antiviral demonstrated verified efficacy not only in cellular systems but also in human-derived respiratory tissues and animal models.

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

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↗