BREAKING! COVID-19 Updates: University Of Bristol Led International Study Finds That The Protein Neuropilin-1 Drives SARS-CoV-2 Infectivity!

COVID-19 Updates: A breakthrough international research led by scientist from University of Bristol-UK along with experts from University of Queensland –Australia, University of Tartu-Estonia, University of Zurich-Switzerland, Biological Research Centre (BRC), Szeged-Hungary, University of Helsinki-Finland, Institute of Biochemistry-Switzerland, University of Liverpool-UK and Singapore Immunology Network, Agency for Science, Technology-Singapore has potentially identified the protein Neuropilin-1 that makes SARS-CoV-2 highly infectious and able to spread rapidly in human cells.


 
In the abstract summary, the study team said, “SARS-CoV-2, the causative agent of COVID-19, uses the viral Spike (S) protein for host cell attachment and entry. The host protease furin cleaves the full-length precursor S glycoprotein into two associated polypeptides: S1 and S2. Cleavage of S generates a polybasic Arg-Arg-Ala-Arg C-terminal sequence on S1, which conforms to a C-end rule (CendR) motif that binds to cell surface Neuropilin-1 (NRP1) and Neuropilin-2 (NRP2) receptors. Here, we used X-ray crystallography and biochemical approaches to show that the S1 CendR motif directly bound NRP1. Blocking this interaction using RNAi or selective inhibitors reduced SARS-CoV-2 entry and infectivity in cell culture. NRP1 thus serves as a host factor for SARS-CoV-2 infection and may potentially provide a therapeutic target for COVID-19.”
 
The study findings were published in the peer reviewed journal: Science https://science.sciencemag.org/content/early/2020/10/19/science.abd3072
 
The study describe how the virus's ability to infect human cells can be reduced by inhibitors that block a newly discovered interaction between virus and host, demonstrating a potential anti-viral treatment.
 
It was found that unlike other coronavirus, which cause common colds and mild respiratory symptoms, SARS-CoV-2, the causative agent of COVID-19, is highly infective and transmissive. Until now, major questions have remained unanswered as to why SARS-CoV-2 readily infects organs outside of the respiratory system, such as the brain and heart.
 
In order to infect humans, SARS-CoV-2 must first attach to the surface of human cells that line the respiratory or intestinal tracts. Once attached, the virus invades the cell then replicates multiple copies of itself. The replicated viruses are then released leading to the transmission of SARS-CoV-2.
 
The SARS-CoV-2 coronavirus's process of attachment to and invasion of human cells is performed by a viral protein, called the 'Spike' protein. Understanding the process by which the 'Spike' protein recognises human cells is central to the development of antiviral therapies and vaccines to treat COVID-19.
 
In the study, the research groups in Bristol's Faculty of Life Sciences, Professor Dr Peter Cullen from the School of Biochemistry; Dr Yohei Yamauchi, Associate Professor and virologist from the School of Cellular and Molecular Medicine, and Dr  Boris Simonetti, a senior researcher in the Cullen lab, used multiple approaches to discover that SARS-CoV-2 recognises a protein called neuropilin-1 on the s urface of human cells to facilitate viral infection.
 
The study team explained, "In looking at the sequence of the SARS-CoV-2 Spike protein we were struck by the presence of a small sequence of amino acids that appeared to mimic a protein sequence found in human proteins which interact with neuropilin-1. This led us to propose a simple hypothesis: could the Spike protein of SARS-CoV-2 associate with neuropilin-1 to aid viral infection of human cells? Excitingly, in applying a range of structural and biochemical approaches we have been able to establish that the Spike protein of SARS-CoV-2 does indeed bind to neuropilin-1.
 
They added, "Once we had established that the Spike protein bound to neuropilin-1 we were able to show that the interaction serves to enhance SARS-CoV-2 invasion of human cells grown in cell culture. Importantly, by using monoclonal antibodies lab-created proteins that resemble naturally occurring antibodies or a selective drug that blocks the interaction we have been able to reduce SARS-CoV-2's ability to infect human cells. This serves to highlight the potential therapeutic value of our discovery in the fight against COVID-19."
 
Interestingly, scientists at the Technical University of Munich, Germany and the University of Helsinki, Finland, have independently found that neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity.
 
The team added, “Cell entry of SARS-CoV-2 depends on priming by host cell proteases. Our data indicate that a component of SARS-CoV-2 S protein binding to cell surface neuropilins occurs via the S1 CendR motif generated by the furin cleavage of S1/S2. While not affecting cell surface attachment, this interaction promotes entry and infection by SARS-CoV-2 in physiologically relevant cell lines widely used in the study of COVID-19. The molecular basis for the effect is unclear, but neuropilins are known to mediate the internalization of CendR ligands through an endocytic process resembling macropinocytosis. Interestingly, gene expression analysis has revealed an up-regulation of NRP1 and NRP2 in lung tissue from COVID-19 patients.” https://pubmed.ncbi.nlm.nih.gov/32437596/
 
They added, “A SARS-CoV-2 virus with a natural deletion of the S1/S2 furin cleavage site demonstrated attenuated pathogenicity in hamster models. https://pubmed.ncbi.nlm.nih.gov/32301390/ NRP1 binding to the CendR peptide in S1 is thus likely to play a role in the increased infectivity of SARS-CoV-2 compared with SARS-CoV. The ability to target this specific interaction may provide a route for COVID-19 therapies.”
 
The study concluded, "To defeat COVID-19 we will be relying on an effective vaccine and an arsenal of anti-viral therapeutics. Our discovery of the binding of the SARS-CoV-2 Spike to neuropilin-1 and its importance for viral infectivity provides a previously unrecognized avenue for anti-viral therapies to curb the current COVID-19 pandemic."
 
It should also be noted that another study conducted by University of Arizona also found that the SARS-CoV-2 was able to bind to the neuropilin-1 receptors in humans,(NRP-I) in the process disrupting certain pain signals pathways, hence making the human host impervious to pain that might otherwise be critical to alert to any resulting organ or tissue infections and damage! https://www.thailandmedical.news/news/breaking-news-covid-19-study-shows-that-sars-cov-2-can-bind-to-human-host-neuropilin-1-receptor-nrp-1,-blocking-certain-pain-signals-in-host
 
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