Llamas produce a type of antibody called “nanobodies” which are smaller and simpler in structure than human antibodies, making them easy to re-engineer in a lab.
Scientists at the Rosalind Franklin Institute in the UK have used antibodies from llamas to design drugs for the treatment of Covid-19, science-based portal SciTech daily reported.
The immune therapy would specifically target the SARS-CoV-2 virus to prevent it from infecting cells, UK researchers announced on Wednesday.
Clinical testing of the llama-based antibody cocktail could begin in humans later this year.
The team involves researchers from the Rosalind Franklin Institute, Oxford University, Diamond Light Source and Public Health England. The peer-reviewed findings are published in Nature Structural & Molecular Biology.
Animals such as llamas, alpacas and camels produce small single-domain antibodies called “nanobodies,” which are about a quarter of the size of a typical human antibody.
These nanobodies are ideal for using as templates to engineer antibody drugs because of their small size and simple structure compared to human antibodies.
In addition, nanobodies are fairly stable, making it easy to store them for long periods of time after production. They can also be delivered directly to the lungs using an inhaler, making them especially promising for treating respiratory infections such as Covid-19.
The UK researchers developed two different nanobodies derived from a llama named “Fifi” which were shown to be effective in neutralizing the novel SARS-CoV-2 coronavirus that causes Covid-19.
Just a simple drop of blood from the animal was required for obtaining the antibodies that were used as templates in the design of the engineered nanobodies.
The Covid-19 nanobodies were designed using a “lock and key” strategy where they were cut like a key that fits the coronavirus lock, explained Professor James Naismith, director of the Rosalind Franklin Institute and lead researcher on the study.
“With the llama’s antibodies, we have keys that don’t quite fit – they’ll go into the lock but won’t turn all the way round,” he said. “So, we take that key and use molecular biology to polish bits of it, until we’ve cut a key that fits.”
“Then if you get re-infected…your body looks for any [virus particles] with antibodies stuck around them and destroys them,” said Professor Naismith.
