28 research outputs found
HIV-1 Activates T Cell Signaling Independently of Antigen to Drive Viral Spread
Get PDFopen access articleHIV-1 spreads between CD4 T cells most efficiently through virus-induced cell-cell contacts. To test whether this process potentiates viral spread by activating signaling pathways, we developed an approach to analyze the phosphoproteome in infected and uninfected mixed-population T cells using differential metabolic labeling and mass spectrometry. We discovered HIV-1-induced activation of signaling networks during viral spread encompassing over 200 cellular proteins. Strikingly, pathways downstream of the T cell receptor were the most significantly activated, despite the absence of canonical antigen-dependent stimulation. The importance of this pathway was demonstrated by the depletion of proteins, and we show that HIV-1 Env-mediated cell-cell contact, the T cell receptor, and the Src kinase Lck were essential for signaling-dependent enhancement of viral dissemination. This study demonstrates that manipulation of signaling at immune cell contacts by HIV-1 is essential for promoting virus replication and defines a paradigm for antigen-independent T cell signaling
Investigation of the stability and risks of fomite transmission of human coronavirus OC43 on leather
Get PDFopen access articleLimited research exists on the potential for leather to act as a fomite of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or endemic coronaviruses including human coronavirus (HCoV) OC43; this is important for settings such as the shoe manufacturing industry. Antiviral coating of leather hides could limit such risks. This study aimed to investigate the stability and transfer of HCoVOC43 on different leathers, as a surrogate for SARS-CoV-2, and assess the antiviral efficacy of a silver-based leather coating. The stability of HCoV-OC43 (6.6 log10) on patent, full-grain calf, corrected grain finished and nubuck leathers (silver additive-coated and uncoated) was measured by titration on BHK-21 cells. Transfer from leather to cardboard and stainless steel was determined. HCoV-OC43 was detectable for 6 h on patent, 24 h on finished leather and 48 h on calf leather; no infectious virus was recovered from nubuck. HCoV-OC43 transferred from patent, finished and calf leathers onto cardboard and stainless steel up to 2 h post-inoculation (≤3.1–5.5 log10), suggesting that leathers could act as fomites. Silver additive-coated calf and finished leathers were antiviral against HCoV-OC43, with no infectious virus recovered after 2 h and limited transfer to other surfaces. The silver additive could reduce potential indirect transmission of HCoV-OC43 from leather
The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons
Get PDFopen access articleHerpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir
HIV-1 Vpr drives a tissue residency-like phenotype during selective infection of resting memory T cells
Get PDFHIV-1 replicates in CD4+ T cells, leading to AIDS. Determining how HIV-1 shapes its niche to create a permissive environment is central to informing efforts to limit pathogenesis, disturb reservoirs, and achieve a cure. A key roadblock in understanding HIV-T cell interactions is the requirement to activate T cells in vitro to make them permissive to infection. This dramatically alters T cell biology and virus-host interactions. Here we show that HIV-1 cell-to-cell spread permits efficient, productive infection of resting memory T cells without prior activation. Strikingly, we find that HIV-1 infection primes resting T cells to gain characteristics of tissue-resident memory T cells (TRM), including upregulating key surface markers and the transcription factor Blimp-1 and inducing a transcriptional program overlapping the core TRM transcriptional signature. This reprogramming is driven by Vpr and requires Vpr packaging into virions and manipulation of STAT5. Thus, HIV-1 reprograms resting T cells, with implications for viral replication and persistence
HIV-1 Vpr drives a tissue residency-like phenotype during selective infection of resting memory T cells.
Get PDFopen access articleHIV-1 replicates in CD4+ T cells, leading to AIDS. Determining how HIV-1 shapes its niche to create a permissive environment is central to informing efforts to limit pathogenesis, disturb reservoirs, and achieve a cure. A key roadblock in understanding HIV-T cell interactions is the requirement to activate T cells in vitro to make them permissive to infection. This dramatically alters T cell biology and virus-host interactions. Here we show that HIV-1 cell-to-cell spread permits efficient, productive infection of resting memory T cells without prior activation. Strikingly, we find that HIV-1 infection primes resting T cells to gain characteristics of tissue-resident memory T cells (TRM), including upregulating key surface markers and the transcription factor Blimp-1 and inducing a transcriptional program overlapping the core TRM transcriptional signature. This reprogramming is driven by Vpr and requires Vpr packaging into virions and manipulation of STAT5. Thus, HIV-1 reprograms resting T cells, with implications for viral replication and persistence
Escape Lab: Bringing the investigative approach of antiviral drug discovery to the public in an escape room activity.
Get PDFThe COVID-19 pandemic has shone a light on virology and highlighted the need for public engagement to convey both results and processes behind the research. We designed a 20-minute escape room (Escape Lab) to ask ‘How can antiviral drugs be identified and developed?’
Escape Lab is aimed for children (secondary school-aged and above) and adults, with no expectation of prior scientific expertise. The goal is to find the structure of a potent antiviral compound that a scientist in the lab has discovered. The activities mimicked some of the key stages of our drug-discovery research: (1) screening compounds for antiviral activity; (2) checking cytotoxicity; (3) chemically modifying hit compounds to improve potency. Teams interpreted protocols and results from the scientist’s lab notebook and undertook ‘experiments’ to generate clues for each stage. The team ‘escaped’ the lab when they built a molecular model of the antiviral compound. Successful teams were given certificates and finish times recorded on a leaderboard to generate a sense of competition. Participants could also talk with current researchers to relate the activities to real data generated in our lab.
Escape Lab was run at two events (British Science Festival, Leicester and Leicester Business Festival) in 2022. We had overwhelmingly positive feedback (95% 5-stars) and ~50% of participants seeking to learn more about our research.
Overall, this offers a blueprint for a fun and engaging way to bring research to the public, with the flexibility to update the scenario to incorporate novel research and target different age groups
The Effects of SARS-CoV-2 on the Angiopoietin/Tie Axis and the Vascular Endothelium
No full textSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause potentially life-threatening coronavirus disease (COVID-19). COVID-19 is a multisystem disease and is associated with significant respiratory distress, systemic hyperinflammation, vasculitis, and multi-organ failure. SARS-CoV-2 causes the deterioration of numerous systems, with increasing evidence implying that COVID-19 affects the endothelium and vascular function. The endothelium is important for preserving vascular tone and homeostasis. The overactivation and dysfunction of endothelial cells are significant outcomes of severity in patients with COVID-19. The Angiopoietin 1/Tie 2 pathway plays an important role in endothelium quiescence and vessel stability. The disruption of Angiopoietin/Tie balance affects the vessel contact barrier and leads to vessel leakage, and this in turn causes endothelial dysfunction. Although vascular instability through SARS-CoV-2 is associated with endothelial dysfunction, it is still not understood if the virus affects the Angiopoietin/Tie axis directly or via other mechanisms such as cytokine storm and/or immune response associated with the infection. This review provides an overview of the impact SARS-CoV-2 has on endothelial function and more specifically on the Angiopoietin/Tie pathway
The Stability of Model Human Coronaviruses on Textiles in the Environment and during Health Care Laundering
No full textopen access articleSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) persists on stainless steel and plastic for up to 7 days, suggesting that coronavirus disease 2019 (COVID-19) could be spread by fomite transmission. There is limited research on the stability of SARS-CoV-2 on textiles, with the risk of textiles acting as fomites not being well understood. To date, there does not appear to be any published research on the stability of coronaviruses during laundering, which is required to determine the efficacy of current laundering policies in the decontamination of health care textiles. The aim of this study was to investigate the environmental stability of human coronaviruses HCoV-OC43 and HCoV-229E on different textile fiber types and the persistence of HCoV-OC43 on textiles during domestic and industrial laundering. This study demonstrated that human coronaviruses (5 log10 50% tissue culture infective doses [TCID50]) remain infectious on polyester for ≥72 h, cotton for ≥24 h, and polycotton for ≥6 h; HCoV-OC43 was also able to transfer from polyester to PVC or polyester after 72 h. Under clean conditions, HCoV-OC43 was not detectable on cotton swatches laundered with industrial and domestic wash cycles without temperature and detergent (≥4.57-log10-TCID50 reduction), suggesting that the dilution and agitation of wash cycles are sufficient to remove human coronaviruses from textiles. In the presence of interfering substances (artificial saliva), ≤1.78 log10 TCID50 HCoV-OC43 was detected after washing domestically without temperature and detergent, unlike industrial laundering, where the virus was completely removed. However, no infectious HCoV-OC43 was detected when washed domestically with detergent
Antiviral plant-derived natural products to combat RNA viruses: Targets throughout the viral life cycle
No full textThe file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.There is need for new effective antivirals, particularly in response to the development of antiviral drug resistance and emerging RNA viruses such as SARS-CoV-2. Plants are a significant source of structurally diverse bioactive compounds for drug discovery suggesting that plant-derived natural products could be developed as antiviral agents. This article reviews the antiviral activity of plant-derived natural products against RNA viruses, with a focus on compounds targeting specific stages of the viral life cycle. A range of plant extracts and compounds have been identified with antiviral activity, often against multiple virus families suggesting they may be useful as broad-spectrum antiviral agents. The antiviral mechanism of action of many of these phytochemicals is not fully understood and there are limited studies and clinical trials demonstrating their efficacy and toxicity in vivo. Further research is needed to evaluate the therapeutic potential of plant-derived natural products as antiviral agents
Stability of Model Human Coronaviruses on a Range of Textile Fibre Types
No full textPrevious research indicates that SARS-CoV-2 persists on stainless steel and plastic for 72 hours to 7 days and appears to be less stable on porous surfaces. However, there is limited research on the stability of coronaviruses on a range of textiles, of which the composition and construction could have an effect on its persistence. Determination of the persistence of coronaviruses on textiles is required to evaluate the potential risk of fomite transmission via textiles; this is of particular importance in healthcare settings to inform laundering policies for the adequate decontamination of hospital linens and staff uniforms. The aim of this study is to determine the stability of model human coronaviruses for SARS-CoV-2 on a range of textile fibres and how best to decontaminate them.
Human coronavirus (HCoV) OC43 was cultured on HCT-8 cells and HCoV-229E was cultured on MRC-5 cells. The optimal recovery method of virus from textiles was first determined by comparing the recovery efficiency of HCoV-OC43 from 100% cotton using differing diluents (cell culture media, phosphate buffered saline (PBS) and maximum recovery diluent (MRD)) and recovery methods (vortexing, stomaching and shaking by hand). The stability of HCoV-OC43 and HCoV-229E was then determined on 100% cotton, polyester/cotton blend, 100% polyester and calf leather up to 48 hours. A no virus (culture media only) control was included. Infectious virus was quantified by titration of the supernatant on BHK-21 cells in 96-well plates.
The recovery of HCoV-OC43 from 100% cotton was comparable between PBS and culture media as diluents, whereas recovery was reduced using MRD. Shaking by hand was the most efficient recovery method used, with 98.56% of the inoculum being recovered. The stability of HCoV-OC43 was greatest on polyester, where it remained infectious for at least 6 hours. Investigations into the decontamination of model human coronaviruses under wash parameters are ongoing.
Investigations on the survival of coronaviruses is required to evaluate the infection control risk of contaminated textiles and to identify laundering parameters required to adequately decontaminate linen. This study demonstrates that model coronaviruses survive on textiles, indicating that there may be a risk within the healthcare and domestic environments
