The National Institutes of Health (NIH) scientists have isolated nanobodies against SARS-CoV-2 in a llama. Their results are published in Scientific Reports show that at least one of these nanobodies, called NIH-CoVnb-112, could prevent infections and detect virus particles by attaching to the SARS-CoV-2 spike proteins. The nanobody worked equally well in either liquid or aerosol form, this means it could remain effective after inhalation. Thomas J. "T.J." Esparza, B.S., and David L. Brody, M.D., Ph.D., both co-investigated the study and worked in a brain imaging lab at the NIH's National Institute of Neurological Disorders and Stroke (NINDS).
"For years TJ and I had been testing out how to use nanobodies to improve brain imaging. When the pandemic broke, we thought this was a once in a lifetime, all-hands-on-deck situation and joined the fight," said Dr. Brody the senior author of the study. "We hope that these anti-COVID-19 nanobodies may be highly effective and versatile in combating the coronavirus pandemic."
A nanobody is a special type of antibody naturally produced by the immune systems of camelids and are more stable and less expensive to produce than traditional antibodies. On average, these proteins are about a tenth the weight of most human antibodies. They play a critical role in the immune system's defenses by recognizing proteins on viruses, bacteria, and other invaders, also known as antigens.
"The SARS-CoV-2 spike protein acts like a key. It does this by opening the door to infections when it binds to a protein called the angiotensin converting enzyme 2 (ACE2) receptor, found on the surface of some cells," said Mr. Esparza, the lead author of the study. "We developed a method that would isolate nanobodies that block infections by covering the teeth of the spike protein that bind to and unlock the ACE2 receptor."