Potential drug candidate emerges as llama antibodies found to neutralize COVID-19’s spike protein.
Stories about the potential of antibodies found in llamas have been circulating for a while and OGN Daily first reported this in mid-May: Maybe Llamas are the Solution
It all seemed a bit odd at the time but now the good news is that (according to a paper published in Nature) two nanobodies derived from llamas have been found in tests to neutralize COVID-19 by blocking its interaction with the human receptor that it binds to. The nanobodies are small, stable immune cells similar to various antibodies.
Both of the two llama nanobodies were shown to neutralize live COVID-19 and, when combined with a human antibody, showed particularly high potency and increased neutralization potential.
The development of immunizations for coronaviruses is a well-established process and it is known that the virus possesses a protein which binds to a receptor on the exterior of the cells of an infected individual. Like a boat docking at a wharf, the virus needs a place to ‘dock’ its spike protein, otherwise it cannot enter the cell. Therefore the first objective of scientists and drug companies is to see how they can prevent the binding of the spike protein with the cell receptor.
“Although there is currently no ‘cure’ or vaccine for the disease,” writes James Naismith at the UK's Rosalind Franklin Institute, “passive immunotherapy by transfusing critically ill COVID-19 patients with serum from [recovered] COVID-19… individuals has been shown to improve clinical outcomes.”
“This would suggest that neutralization of the virus, even at a relatively late stage in the disease, may be a useful COVID-19 therapy.”
The two nanobodies can be “deployed to produce a highly neutralizing agent against an emerging viral threat in real time,” to provide “passive immunization of severely ill COVID-19 patients,” say the authors of the paper in Nature.
The Rosalind Franklin Institute has filed a patent on the llama nanobodies.