Fundamental features of the SARS-CoV-2 virus have been revealed for the first time by UK and USA scientists, it has been claimed.
Researchers at the University of Southampton, working with the University of Texas, USA, have produced the first model of a spike of the virus, which shows how it disguises itself to enter human cells undetected, and the viral proteins that are the target of antibodies and vaccine research.
The SARS-CoV-2 virus has a large number of spikes sticking out of its surface that are coated in glycans, which disguise their viral proteins and help them evade the body’s immune system.
Professor Max Crispin and his team studied the structure of the glycans covering the surface of a mimetic of a viral spike to map the structure, thus providing important information about how accessible the viral protein surface is to antibodies.
“By coating themselves in sugars, viruses are like a wolf in sheep’s clothing,” Professor Crispin said. “But one of the key findings of our study is that despite how many sugars there are, this coronavirus is not as highly shielded as some other viruses.
“Viruses like HIV, which hang around in one host, have to evade the immune system constantly and they have a really dense coat of glycans as a shield to the immune system; but in the case of the coronavirus, the lower shielding by sugars attached to it may reflect that it is a ‘hit and run’ virus, moving from one person to the next.
“However, the lower glycan density means there are fewer obstacles for the immune system to neutralise the virus with antibodies. So this is a very encouraging message for vaccine development.”
The research team have now released their findings ahead of peer-review on the BioRxiv preprint server.
They are now working with partners who have developed candidate vaccines, including Professor Rogier Sanders at the University of Amsterdam, and are now analysing the glycan contentin Southampton.
Watanbe Y, Allen JD, Wrapp D et al. Site-specific analysis of the SARS-CoV-2 glycan shield. BioRxiv 8 April 2020.
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