Scientists say they’ve discovered an antibody that blocks infection by SARS-CoV-2, the coronavirus behind the current global health crisis.
The antibody, known as 47D11, targets the deadly virus’s infamous ‘spike protein’, which it uses to hook onto cells and insert its genetic material.
Tests in mice cells showed that 47D11 binds to this protein and prevents it from hooking on – effectively neutralising it.
The breakthrough offers hope of a treatment for the respiratory disease COVID-19, which has killed more than 235,000 people to date.
Researchers said the antibody, if injected into humans, could alter the ‘course of infection’ or protect an uninfected person exposed to someone with the virus.
The European research team identified the antibody from 51 cell lines from mice that had been engineered to carry human genes.
The antibody targets the novel coronavirus that caused the 2003 SARS outbreak, known as SARS-CoV-1.
However, scientists claim that it can also neutralise SARS-CoV-2, which is from the same family of coronaviruses as SARS-CoV-1.
‘This research builds on the work our groups have done in the past on antibodies targeting the SARS-CoV that emerged in 2002/2003,’ said co-lead author Professor Berend-Jan Bosch at Utrecht University.
‘Using this collection of SARS-CoV antibodies, we identified an antibody that also neutralises infection of SARS-CoV-2 in cultured cells.
‘Such a neutralising antibody has potential to alter the course of infection in the infected host, support virus clearance or protect an uninfected individual that is exposed to the virus.’
Dr Bosch added that the antibody’s ability to neutralise both strains of SARS-CoV suggests that it may have potential in mitigation of diseases caused by future emerging coronaviruses.
SARS-CoV-2, which is responsible for the illness known as COVID-19, is spread through small respiratory droplets from sneezing or coughing.
The virus hooks onto a locking point on human cells to insert its genetic material, makes multiples copies of itself and spreads throughout the body.
In the lab, researchers injected mouse cells with a variety of ‘spike proteins’ of various coronaviruses, including SARS and MERS.
The team then isolated 51 neutralising antibodies produced by the mouse cells that target the spike protein – one of which, 47D11, could prevent infection of cells with SARS-CoV-1.
The successful antibody, 47D11, binds to an enzyme called ACE2 – which is also present in SARS-CoV-2 – and acts as the virus’s ‘doorway’ to human cells.
‘The researchers in this study have developed an antibody that binds to the spike and blocks virus entry into cells,’ said Dr Simon Clarke, professor of Cellular Microbiology at University of Reading, who wasn’t involved in the study.
‘Antibodies like this can be made in the lab instead of purified from people’s blood and could conceivably be used as a treatment for disease, but this has not yet been demonstrated.
‘While it’s an interesting development, injecting people with antibodies is not without risk and it would need to undergo proper clinical trials.’