OXFORD, England – Since the start of the coronavirus pandemic, scientists say the illness may come from animals like bats. Now, animals may help doctors stop the virus. Researchers from England say llama antibodies are helping to create a new treatment to fight severe cases of COVID-19.
A team from the Rosalind Franklin Institute, Oxford University, Diamond Light Source, and Public Health England have found a way to create “nanobodies” that can neutralize SARS-CoV-2, the virus which causes COVID-19.
“This research is a great example of teamwork in science, as we have created, analyzed and tested the nanobodies in 12 weeks,” says Ray Owens of Oxford University in a media release. “This has seen the team carry out experiments in just a few days, that would typically take months to complete. We are hopeful that we can push this breakthrough on into pre-clinical trials.”
Blocking the way
The nanobodies work by binding to the SARS-CoV-2 virus and blocking its entry into human cells. The virus cells have a set of proteins on its surface known as spike proteins. These spikes help the virus break into human cells, binding to the human ACE-2 receptor. This gene is commonly found in the lungs, where COVID-19 can cause severe complications.
Researchers say their nanobodies attach to the spike proteins, making them unable stick to ACE-2 genes. Since the virus can’t enter human cells, the llama nanobodies effectively neutralize the virus.
“The electron microscopy structures showed us that the three nanobodies can bind to the virus spike, essentially covering up the portions that the virus uses to enter human cells,” explains David Stuart of Diamond Light Source and Oxford University.
Fifi, the COVID-19 fighting llama
Although the researchers say they have multiple nanobodies already, they plan to test more. To do this, they are screening antibodies from a llama named Fifi at the University of Reading. The antibodies were collected after Fifi was immunized with harmless, purified virus proteins.
After the immunization, Fifi’s immune system produces a variety of antibodies different from the ones originally discovered. These new antibodies will allow scientists to test cocktails of different nanobodies to see which ones are most effective at neutralizing SARS-CoV-2.
“We were able to combine one of the nanobodies with a human antibody and show the combination was even more powerful than either alone,” says James Naismith, director of The Rosalind Franklin Institute.
“Combinations are particularly useful since the virus has to change multiple things at the same time to escape; this is very hard for the virus to do. The nanobodies also have potential as a powerful diagnostic.”
The study is published in Nature Structural & Molecular Biology.