Biology subjects

Jones, I. M.

Publications and source records attributed to Jones, I. M..

5 recordsLinked to original sources

bioRxiv2025

Interactions between tick-borne encephalitis virus non-structural protein 1 and blood-brain barrier tight junction proteins: potential clues to strain-specific neuropathogenicity

Tick-borne encephalitis virus (TBEV) invades the central nervous system (CNS) through strain-specific mechanisms that remain poorly understood. In mosquito-borne orthoflaviviruses such as dengue and yellow fever viruses, the non-structural protein 1 (NS1) has been shown to disrupt endothelial barrier integrity by targeting tight junction proteins (TJPs), thereby facilitating viral neuroinvasion. However, comparable mechanisms in TBEV remain largely unexplored. Here, we investigate the potential interaction of NS1 from high (Hypr)- and low (Vs)-pathogenicity TBEV strains to different blood-brain barrier (BBB) TJPs, using AlphaFold3 (AF3) multimer modelling and in vitro binding assays. We find that NS1 from the highly pathogenic strain exhibits higher predicted interactions with multiple TJPs, including two junctional adhesion molecules (JAM-A, JAM-B) and Claudin-10, which are critical component of the paracellular barrier. In contrast, low pathogenic strain Vs interaction was limited to JAM-A and Claudin-5. Experimental validation using recombinant NS1 proteins revealed strain-specific binding profiles: Hypr NS1 displayed high-affinity, saturable direct binding to immobilized JAM-A (KD = 0.271 {micro}g/mL), whereas Vs NS1 showed negligible interaction (KD = 0.000023 {micro}g/mL). No binding to ZO-1, a barrier scaffold lacking an extracellular domain, was observed for either strain. This differential interaction may be modulated by 22 specific amino acid substitutions localized to the Wing and {beta}-ladder domains, which distinguish the highly neurovirulent Hypr strain from the avirulent Vs strain. Notably, despite its weak JAM-A interaction, the Vs strain is associated with slow-progressing infections that can culminate in chronic neurological disease, highlighting the need for further investigation into noncanonical pathways of neuroinvasion. GraphicsO_ST_ABSA graphical illustration of low-and high-pathogenic TBEV mediated compromised blood-brain barrier (BBB)C_ST_ABSThe left panel illustrates the cellular architecture of the BBB, including pericytes, endothelial cells, astrocytes, and blood vessels. The central panel depicts an intact BBB with tight junction proteins (JAM-A, ZO-1, Claudin) maintaining barrier integrity. The right panel shows strain-specific pathogenesis, highlighting a direct interaction between NS1 from the highly pathogenic Hypr strain and JAM-A, which may contribute to differential neuroinvasive outcomes. The schematic was created using BioRender.com. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=78 SRC="FIGDIR/small/669603v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@3e03c2org.highwire.dtl.DTLVardef@168e8f8org.highwire.dtl.DTLVardef@9703f1org.highwire.dtl.DTLVardef@83e24a_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2022

Protease-independent production of poliovirus virus-like particles in Pichia pastoris: Implications for efficient vaccine development and insights into capsid assembly.

The production of enterovirus virus-like particles (VLPs) which lack the viral genome have great potential as vaccines for a number of diseases, such as poliomyelitis and hand, foot-and-mouth disease. These VLPs can mimic empty capsids, which are antigenically indistinguishable from mature virions, produced naturally during viral infection. Both in infection and in vitro, capsids and VLPs are generated by the cleavage of the P1 precursor protein by a viral protease. Here, using a stabilised poliovirus 1 (PV-1) P1 sequence as an exemplar, we show the production of PV-1 VLPs in Pichia pastoris in the absence of the potentially cytotoxic protease, 3CD, instead using the porcine teschovirus 2A (P2A) peptide sequence to terminate translation between individual capsid proteins. We compare this to protease-dependent production of PV-1 VLPs. Analysis of all permutations of the order of the capsid protein sequences revealed that only VP3 could be tagged with P2A and maintain native antigenicity. Transmission electron microscopy of these VLPs reveals the classic picornaviral icosahedral structure. Furthermore, these particles were thermostable above 37{degrees}C, demonstrating their potential as next generation vaccine candidates for PV. Finally, we believe the demonstration that native antigenic VLPs can be produced using protease-independent methods opens the possibility for future enteroviral vaccines to take advantage of recent vaccine technological advances, such as adenovirus-vectored vaccines and mRNA vaccines, circumventing the potential problems of cytotoxicity associated with 3CD, allowing for the production of immunogenic enterovirus VLPs in vivo.

microbiology↗

bioRxiv2021

SARS-CoV-2 Virus like Particles produced by a single recombinant baculovirus generate potent neutralizing antibody that protects against variant challenge

The Covid-19 pandemic caused by SARS-CoV-2 infection has highlighted the need for the rapid generation of efficient vaccines for emerging disease. Virus-like particles, VLPs, are an established vaccine technology that produces virus-like mimics, based on expression of the structural proteins of a target virus that can stimulate strong neutralizing antibody responses. SARS-CoV-2 is a coronavirus where the basis of VLP formation has been shown to be the co-expression of the spike, membrane and envelope structural proteins. Here we describe the generation of SARS-CoV-2 VLPs by the co-expression of the salient structural proteins in insect cells using the established baculovirus expression system. VLPs were heterologous [~]100nm diameter enveloped particles with a distinct fringe that reacted strongly with SARS-CoV-2 convalescent sera. In a Syrian hamster challenge model, a non-adjuvanted VLPs induced neutralizing antibodies to the VLP-associated Wuhan S protein, reduced virus shedding following a virulent challenge with SARS-CoV-2 (B.1.1.7 variant) and protected against disease associated weight loss. Immunized animals showed reduced lung pathology and lower challenge virus replication than the non-immunized controls. Our data, using an established and scalable technology, suggest SARS-CoV-2 VLPs offer an efficient vaccine that mitigates against virus load and prevents severe disease.

microbiology↗

bioRxiv2021

Identification of host antiviral genes differentially induced by clinically diverse strains of Tick-Borne Encephalitis Virus

Tick Borne Encephalitis Virus (TBEV) is an important human arthropod-borne virus, which causes tick-borne encephalitis (TBE), an acute viral infection of the central nervous system (CNS) that causes neurological symptoms of varying severity. TBEV is prevalent in large parts of central- and northern-Europe as well as Northern Asia, and strains of varying pathogenicity have been described. Both host and viral specific characteristics have been postulated to determine the outcome of TBEV infection, but the exact basis of their clinical variability remains undefined. Here, we report the generation of Spinach RNA aptamer labelled TBEV replicons of high (Hypr) and low (Vs) pathogenicity isolates and perform the first direct comparison of both strains in cell culture. We show that pathogenic Hypr replicates to higher levels than Vs in mammalian cells, but not in arthropod cells, and that the basis of this difference maps to the NS5 region, encoding the methyltransferase and RNA polymerase. For both Hypr and Vs strains, NS5 and the viral genome localized to defined intracellular structures typical of positive strand RNA viruses, but Hypr was associated with significant activation of IRF-3, caspase-3 and caspase-8, whilst Vs activated Akt, affording protection against caspase-mediated apoptosis. Activation of TIAR and the formation of cytoplasmic stress granules were an additional early feature of Vs but not Hypr replication. Taken together, these findings highlight NS5 and novel host cell responses as key underling factors for the differential clinical characteristics of TBEV strains. ImportanceTick-borne encephalitis virus (TBEV) is an emerging virus of the flavivirus family spread by ticks. Tick bite can transfer the virus and lead to a febrile infection, Tick-borne encephalitis, of varying severity. There is no specific therapeutic treatment and control in endemic areas is by vaccination. The basis of the different pathologies shown following TBEV infection, from mild to fatal, is not clear although the virus genotype clearly has a role. Mapping the basis of their differential effects would allow focus on the stages of the replication cycle responsible, which might guide the development of therapeutic interventions or the creation of purposefully attenuated strains as candidate vaccines.

microbiology↗

bioRxiv2020

Recombinant SARS-CoV-2 spike proteins for sero-surveillance and epitope mapping

The newly emergent SARS-CoV-2 coronavirus is closely related to SARS-CoV which emerged in 2002. Studies on coronaviruses in general, and SARS in particular, have identified the virus spike protein (S) as being central to virus tropism, to the generation of a protective antibody response and to the unambiguous detection of past infections. As a result of this centrality SARS-CoV-2 S protein has a role in many aspects of research from vaccines to diagnostic tests. We describe a number of recombinant forms of SARS-CoV-2 S expressed in commonly available expression systems and their preliminary use in diagnostics and epitope mapping. These sources may find use in the current and future analysis of the virus and the Covid-19 disease it causes.

microbiology↗