Extracellular vesicle-mediated endothelial apoptosis and EV-associated proteins correlate with COVID-19 disease severity. July 2021, Journal of Extracellular Vesicles. doi:10.1002/jev2.12117
COVID-19 pathogenesis was the topic of a study published by a group at the University of Kansas Medical Center, US, who studied the protein cargo of plasma EVs from 84 hospitalised patients with varying stages of COVID-19 disease severity. qEV-isolated EV-associated proteins were compared to those from uninfected controls with matched epidemiological and clinical characteristics. A targeted proteomics approach was used; specifically, a multi-plex DNA-coupled immunoassay with oligonucleotide-labelled antibodies. Key differences across groups related to EN-RAGE (a newly identified proinflammatory receptor), TF (tissue factor, a cofactor and receptor key to the initiation of blood coagulation) and IL-18R1. A potential prognostic value was identified for EV EN-RAGE levels, which was strongly correlated with the length of hospitalisation and disease severity. COVID-19-associated alterations in EV cargo corresponded to enhanced apoptosis of pulmonary vascular endothelial cells, with the extent of apoptosis occurring in the order of disease severity.
Development and preclinical evaluation of virus-like particle vaccine against COVID-19 infection. September 2021, Allergy. doi: 10.1111/all.15091
This paper describes the preclinical development of a vaccine against the SARS-CoV-2 virus, by a collaborative group of Turkey-based researchers. The work aimed to develop a virus-like particle (VLP) vaccine that would reduce reliance on spike protein-based vaccines, and potentially broaden the breadth of the immune response. First, a VLP vaccine was designed to express the spike protein stabilised in its pre-fusion form. The second VLP vaccine was designed to express four antigens: the S protein (in its prefusion form with proline substitutions), and membrane (M), nucleocapsid (N), envelope (E) SARS-CoV-2 structural proteins. Several adjuvants were also explored. Another focus of the study involved implementing proline substitutions into the spike protein to varying degrees and assessing the effect on immunogenicity. Respective VLPs were characterized using several techniques including Izon’s tunable resistive pulse sensing (TRPS) platform, which enabled the group to show that assembled VLPs were similar in size to the authentic virion. A VLP vaccine developed from this study is currently being evaluated in a phase I clinical trial (NCT04818281).
Oncolytic virus purification with periodic counter-current chromatography. March 2021, Biotechnology and Bioengineering. doi:10.1002/bit.27779
To explore ways to improve productivity, robustness and control, Mendes et al. describe the use of a continuous chromatography step for the intermediate purification of an oncolytic adenovirus for application as biopharmaceuticals. They tested the stability of the system under a range of different scenarios which could potentially impact virus recovery and stability. Here, TRPS was used to obtain particle size distribution of the oncolytic virus preparations and help in selection of best scenario to increase productivity.
Teriflunomide Inhibits JCPyV infection and spread in glial cells and choroid plexus epithelial cells. September 2021, International Journal of Molecular Sciences. doi:10.3390/ijms22189809
The context of this work can be gauged by the title of the special issue in which it featured: ‘Multiple Sclerosis and Demyelinating Pathologies: Mechanisms and Therapeutic Frontiers’. Most therapies for relapsing-remitting multiple sclerosis (RRMS) increase the risk of a virus-induced demyelinating disease called progressive multifocal leukoencephalopathy (PML) – but teriflunomide is one exception. This in vitro work describes the antiviral activity of teriflunomide in choroid plexus epithelial cells and astrocytes against JC polyomavirus (JCPyV), the causative agent of PML. Another aspect of this study explored EV isolation and subsequent EV-DNA analysis, to see if EV analysis improved the detection of JCPyV in patient samples compared to analysis of bulk biofluids. Here, EVs were separated using Izon’s qEV isolation platform, followed by digital droplet PCR screening for EV-associated JCPyV DNA.
Efficient and reproducible depletion of hepatitis B virus from plasma derived extracellular vesicles. December 2020, Journal of Extracellular Vesicles. doi:10.1002/jev2.12040
A separation protocol featuring qEV isolation has created opportunities for studying the impact of EVs on viral infection. Jung et al. (2020) used the qEV platform to remove unbound antibody and the majority of Hepatitis B virions from a plasma sample incubated with a hepatitis B antibody, prior to a final affinity-based purification step for residual virions and subviral filaments that overlapped in size with EVs. Jung explained the implications of her work in this more in-depth summary, which you can read here: ‘Separation Protocol Opens Doors to Functional EV-Virus Studies’: “The reproducibility of the qEV isolation platform helped a lot to establish this. It’s also good that the qEV platform removes the antibodies, which also was a fundamental part of our protocol – that the column also not only removes HBV, but also the antibodies as an essential step of the pre-purification process.”