Biology subjects

Sugrue, R. J.

Publications and source records attributed to Sugrue, R. J..

5 recordsLinked to original sources

bioRxiv2026

Evidence for a biphasic mechanism of virus transmission of the human metapneumovirus in LLC-MK2 cell monolayers.

We examined transmission of the human metapneumovirus (HMPV) in LLC-MK2 cell monolayers using a low multiplicity of infection (moi). In this low moi infection model HMPV transmission initially occurred by localised cell-to-cell transmission, and the virus infectivity remained largely cell associated. At the later stages of infection more widespread virus transmission occurred and was associated with the presence of cell-free virus. The appearance of the cell-free virus correlated with changes in plasma membrane integrity and increased membrane permeability in the cell monolayers. Imaging analysis of HMPV infected cells at the early stages of infection showed the presence of numerous virus filaments attached to the surface of HMPV-infected cells. At the later stages of infection both virus filaments and virus particles with a spherical morphology that was attached to the distal ends of the virus filaments was noted. A proportion of these spherical particles detached from the virus filaments and attached to adjacent non-infected cells at the later stages of infection. The activation of the JNK and MAPKp38 signalling pathways in HMPV-infected cells correlated with increased HMPV replication and appearance of the cell-free virus infectivity. In addition, after the initial phase of STAT1 activation in HMPV-infected cells, both reduced expression of the STAT1 protein and the activated STAT1 protein occurred as the infection proceeded. Collectively, these data provide evidence for a biphasic mode of HMPV transmission involving different virus particle morphologies, a localised virus transmission by virus filaments followed by widespread virus transmission involving cell-free virus particles.

microbiology↗

bioRxiv2026

Evaluating the use of siRNA to silence the expression of the H5N2 virus polymerase genes as strategy to block the transmission of the avian H5N2 virus in mammalian cells.

We prepared siRNA libraries against the H5N2 virus NP gene, and the PA, PB1 and PB2 genes that express the proteins that form the virus polymerase complex. The antiviral activity of the siRNA libraries in H5N2 virus infected cells was initially assessed by using qPCR to measure the corresponding mRNA levels in the siRNA-treated cells. In this way siRNA molecules within each library were identified that exhibited to a greater than 70% reduction in levels of each target mRNA. A selection of these siRNA molecules was further evaluated for their antiviral activity in a multi-cycle H5N2 MDCK cell model. The siRNA molecules identified were successful in blocking virus transmission and lead to a reduction in influenza virus progeny virus production. This antiviral activity correlated with both the inhibition of nuclear export of the newly formed RNP complexs that arise from the transcriptional activity of the input virus, and the inhibition of the polymerase activity of the newly formed virus polymerase complexes. This study highlights the potential use of siRNA as a strategy to block virus transmission by targeting the avian influenza virus polymerase complex.

microbiology↗

bioRxiv2025

Analysis of the surface topology of respiratory syncytial virus particles that form on the surface of virus-infected cells.

The surface topology of virus filaments on respiratory syncytial virus (RSV)-infected cells was examined using field emission gun-scanning electron microscopy (FEG-SEM) and atomic force microscopy (AFM). FEG-SEM analysis of the surface of RSV-infected cells labelled with an anti-G protein antibody revealed the presence of virus filaments and clusters of the G protein distributed intermittently along their surface. RSV-infected cells thinly coated with chromium were imaged using FEG-SEM and revealed a distinct structured surface topology consisting of closely packed surface domains. The G protein clusters were only associated within a subset of these domains which suggested that this structured topology was mainly derived from the host cell, and the presence of the cell glycocalyx that coats the virus filaments was further suggested. Imaging of RSV-infected cells using AFM was undertaken as a different but complementary approach to the FEG-SEM analysis. Imaging using AFM revealed a similar structured surface topology on the virus filaments to that observed in the FEG-SEM analysis, indicating the consistency in the appearance of the virus surface topology using these different methods. Collectively, this study provides the first detailed imaging of the surface topology of the virus filaments as they form on RSV-infected cells. The imaging data is consistent with the envelopment of the virus filaments by the glycocalyx and highlights the complexity of the spatial organisation within the viral envelope.

microbiology↗

bioRxiv2024

Evidence that the SARS-CoV-2 S protein undergoes a conformational change at the Golgi Complex that leads to the formation of virus neutralising antibody binding epitopes in the S1 protein subunit.

Recombinant SARS-CoV-2 S protein expression was examined in Vero cells by imaging using the human monoclonal antibody panel (PD4, PD5, sc23, and sc29). The PD4 and sc29 antibodies recognised conformational specific epitopes in the S2 protein subunit at the Endoplasmic reticulum and Golgi complex. While PD5 and sc23 detected conformationally specific epitopes in the S1 protein subunit at the Golgi complex, only PD5 recognised the receptor binding domain (RBD). A comparison of the staining patterns of PD5 with non-conformationally specific antibodies that recognises the S1 subunit and RBD suggested the PD5 recognised a conformational structure within the S1 protein subunit. Our data suggests the antibody binding epitopes recognised by the human monoclonal antibodies formed at different locations in the secretory pathway during S protein transport, but a conformational change in the S1 protein subunit at the Golgi complex formed antibody binding epitopes that are recognised by virus neutralizing antibodies.

microbiology↗

bioRxiv2023

Identifying repurposed drugs with moderate anti-influenza virus activity through computational prioritization of drug-target pairs

Influenza A virus (IAV) causes up to five million cases of severe illness and half a million deaths worldwide each year. While there are a few clinically approved drugs for treating IAV, they are challenged by the rapid evolution of the virus leading to emergence of drug resistance and the adverse effects of the drugs. Targeting host cellular factors that support virus replication could limit resistance, increase the broad-spectrum antiviral properties of drugs, and benefit from repurposing drugs already existing against those factors. However, selecting the right drug-target pairs with low toxicity and minimal adverse effects has been challenging, even though hundreds of cellular host factors have been identified. In this study, we applied a computational and knowledge-based drug-target prioritization approach to identify promising drug-target pairs. We selected five pairs for experimental validation: telmisartan-Angiotensin II receptor, type 1 (AGTR1), metoclopramide hydrochloride-Cholinergic receptor muscarinic 1 (CHRM1), cefepime hydrochloride-phosphogluconate dehydrogenase (PGD), ranolazine dihydrochloride-sodium channel voltage-gated type v alpha subunit (SCN5A), and ofloxacin-topoisomerase II alpha 170kDa (TOP2A). Except for cefepime hydrochloride, all four drugs showed significant plaque reduction in Madin Darby canine kidney (MDCK) cells. In the immunofluorescence assay, metoclopramide hydrochloride, ranolazine dihydrochloride, and telmisartan showed antiviral activity in MDCK and/or adenocarcinoma human alveolar basal epithelial (A549) cell lines. In conclusion, our approach can prioritize and identify drugs with antiviral activity against influenza virus. Refining and strengthening such approaches could be valuable for rapid antiviral discovery and pandemic preparedness. HighlightsO_LIComputational drug-target prioritization indicated drugs for validation C_LIO_LITelmisartan showed anti-influenza virus activity in MDCK cells C_LIO_LIMetoclopramide and ranolazine showed anti-influenza activity in A549 and MDCK cells C_LI

systems biology↗