Biology subjects

Scott, S. D.

Publications and source records attributed to Scott, S. D..

4 recordsLinked to original sources

bioRxiv2026

Epigenetic regulation of DPP4 receptor expression by NONO enables replication of MERS-CoV

Middle East respiratory syndrome coronavirus (MERS-CoV), first reported in 2012, belongs to the Betacoronavirus genus, including SARS-CoV and SARS-CoV-2. Human-to-human transmission of MERS-CoV appears inefficient, but repeated spillover events have been reported from at least 27 countries, raising concern for future emergent events. Coronaviruses (CoVs) rely extensively on host proteins to support their replication. Several studies have implicated the paraspeckle non-POU domain-containing octamer-binding protein (NONO) as an RNA-binding protein (RBP) that binds to CoV genomes, but the role of this protein in regulating replication is unknown. Here, we show that NONO is required for expression of dipeptidyl peptidase 4 (DPP4, also known as CD26), the major cellular receptor required for MERS-CoV attachment and entry. NONO did not impact DPP4 mRNA processing or stability but instead promoted DPP4 transcription through control of active H3K4me3 and repressive H3K27me3 histone modifications at the DPP4 locus. Together, these findings identify NONO as a key proviral host factor for MERS-CoV and reveal an epigenetic mechanism linking a host RBP to viral entry receptor expression that may represent a target for therapeutic strategies.

microbiology↗

bioRxiv2026

Serine proteases are required to activate influenza D virus haemagglutinin-esterase fusion (HEF) protein

Influenza D virus (IDV), the most recently identified member of the Orthomyxoviridae, was first isolated from pigs but cattle have been identified as the reservoir host. To date, IDV has not been confirmed to cause human disease. Like the haemagglutinin (HA) of influenza A virus (IAV) and the haemagglutinin-esterase fusion (HEF) protein of influenza C virus (ICV), the IDV HEF is produced as a precursor protein (HEF0) that must be proteolytically cleaved by host cell proteases (into HEF1 and HEF2) to gain its fusion capacity. The proteases that activate IAV HA have been extensively studied, but those responsible for activation of IDV HEF were unknown. Identifying these proteases is key to understanding early virus-host interactions and host restriction. Therefore, we generated ICV and IDV pseudotyped viruses (PVs) in HEK 293T producer cells with or without co-transfection of plasmids expressing different type II serine proteases. Subsequent transduction of swine testicular (ST) cells indicated strong activation of both ICV and IDV PVs by the human airway trypsin-like protease (HAT) and its swine homologue (swAT). Furthermore, like influenza A/Puerto Rico/8/34 (H1N1) virus, addition of exogenous protease is not essential for IDV replication in MDCK II cells, most likely due to endogenous expression of matriptase. In conclusion, our data unveil new information on host cell proteases that activate ICV and IDV HEF proteins. Importantly, the data suggest that protease specificity is not a factor in restriction of IDV replication in the human upper respiratory tract.

microbiology↗

bioRxiv2022

Application and comparison of lyophilisation protocols to enhance stable long-term storage of filovirus pseudotypes for use in antibody neutralisation tests

Filoviruses encompass highly pathogenic viruses placing sporadic public health burden on countries affected. Efforts for improved diagnostics and surveillance are needed considering the recent Ebola outbreaks in Africa. The need for high containment facilities can be circumvented by the use of pseudotype viruses (PV), which can be handled in low containment, for tropism, drug screening, vaccine immunogenicity and serosurveillance studies. In this study we assessed stability and functionality after long-term storage of lyophilised filovirus pseudotypes for use in neutralisation assays. Lyophilised Ebola and Marburg PVs retained production titres for at least two years when stored at +4{degrees}C or less. Lyophilised Ebola PVs performed similarly to non-lyophilised PVs in neutralisation assays after reconstitution. When stored at high temperatures (+37{degrees}C), lyophilised PVs did not retain titres after one-month storage, however, when lyophilised using pilot scale facilities EBOV PVs retained titres and performed well in neutralisation assays after one-month storage at 37{degrees}C suggesting removing residual moisture might be crucial for avoiding cold-chain transportation. Lyophilisation could allow reagents to be transported more efficiently as well as reducing costs for a future serological kit.

microbiology↗

bioRxiv2021

Establishment of pan-Influenza A (H1-H18) and pan-Influenza B (pre-split, Vic/Yam) Pseudotype Libraries for efficient vaccine antigen selection

We have developed an influenza hemagglutinin (HA) pseudotype library encompassing Influenza A subtypes HA1-18, and Influenza B subtypes (both lineages) to be employed in influenza pseudotype microneutralization (pMN) assays. The pMN is highly sensitive and specific for detecting virus-specific neutralizing antibodies against influenza viruses and can be used to assess antibody functionality in vitro. Here we show the production of these viral HA pseudotypes and their employment as substitutes for wildtype viruses in influenza serological and neutralization assays. We demonstrate its utility in detecting serum response to vaccination with the ability to evaluate cross-subtype neutralizing responses elicited by specific vaccinating antigens. Our findings may inform further pre-clinical studies involving immunization dosing regimens in mice and may help in the creation and selection of better antigens for vaccine design. These HA pseudotypes can be harnessed to meet strategic objectives that contribute to the strengthening of global influenza surveillance, expansion of seasonal influenza prevention and control policies, and strengthening pandemic preparedness and response.

immunology↗