A team of researchers from the Indian Institute of Science (IISc) has invented an artificial protein envelope to fight against COVID-19, an official IISc statement announced on Tuesday.
During the first wave of COVID-19, when Saumitra Das, a professor in the Department of Microbiology and Cell Biology (MCB), IISc, and his colleagues were sequencing thousands of samples every day to look for variants of SARS-CoV- 2 as part of INSACOG, the Indian government’s genome monitoring initiative, they were racing against time to track mutations as they appeared.
“If we wanted to predict whether any of these mutations were going to be dangerous from a public health perspective, we needed an assay system,” Das said.
The widely followed testing protocol involved isolating the virus from samples, creating multiple copies of the virus, and studying its transmissibility and effectiveness in entering living cells. Working with such a highly infectious virus is dangerous and requires a biosafety level 3 (BSL-3) lab, but there were only a handful of such labs across the country equipped to handle such viruses.
To solve this problem, Das and his team, together with collaborators from IISc, have now developed and tested a new virus-like particle (VLP) – a non-infectious nanoscale molecule that looks and behaves like the virus but does not contain not its native genetic material — in a study published in Microbiological spectrum.
These VLPs have several uses. They can not only be used to safely study the effect of mutations that can arise in SARS-CoV-2 – without requiring a BSL-3 facility – but can also potentially be developed into a vaccine candidate that can trigger a response. immune system in our body.
Soma Das from the Department of Biochemistry and one of the study authors added that these VLPs can also be used to reduce the time needed to screen for drugs that can fight the virus.
Das’ lab had previously studied the hepatitis C virus for 28 years. They showed that VLPs can be used as candidate vaccines to trigger an immune response.
SARS-CoV-2 replicates by producing each structural protein separately and then assembling them into a shell with the genetic material inside to form an active virus particle. To recreate this, the team chose a baculovirus – a virus that affects insects but not humans – as the vector (carrier) to synthesize the VLPs, as it has the ability to produce and assemble all of these proteins, and to replicate quickly.
Next, the researchers analyzed the VLPs under a transmission electron microscope and found that they were just as stable as native SARS-CoV-2. At 4 degrees Celsius, the VLP could attach to the surface of the host cell, and at 37 degrees Celsius (normal human body temperature), it could enter the cell.
When the team injected a high dose of VLP into mice in the lab, it did not affect liver, lung or kidney tissue. To test its immune response, they administered a primary injection and two booster injections to mouse models with an interval of 15 days, after which they found a large number of antibodies generated in the mice’s blood serum.
The researchers have filed a patent application for their VLP and they hope to turn it into a vaccine candidate. They also plan to study the effect of VLP in other animal models, and possibly in humans.
The above article was published by a news agency with minimal changes to the title and text.