Combating COVID-19 with llama nanobodies
NIH scientists showed that anti-COVID-19 nanobodies from a llama may be an effective tool in the battle against the COVID-19 virus. Courtesy of Brody lab NIH/NINDS.
National Institutes of Health researchers have isolated a set of promising, tiny antibodies, or “nanobodies,” against SARS-CoV-2 that were produced by a llama named Cormac. Preliminary results published in Scientific Reports suggest that at least one of these nanobodies, called NIH-CoVnb-112, could prevent infections and detect virus particles by grabbing hold of SARS-CoV-2 spike proteins. In addition, the nanobody appeared to work equally well in either liquid or aerosol form, suggesting it could remain effective after inhalation. SARS-CoV-2 is the virus that causes COVID-19.
A nanobody is a special type of antibody naturally produced by the immune systems of camelids, a group of animals that includes camels, llamas, and alpacas. On average, these proteins are about a tenth the weight of most human antibodies. This is because nanobodies isolated in the lab are essentially free-floating versions of the tips of the arms of heavy chain proteins, which form the backbone of a typical Y-shaped human IgG antibody. These tips play a critical role in the immune system’s defenses by recognizing proteins on viruses, bacteria, and other invaders, also known as antigens.
Since the pandemic broke, several researchers have produced llama nanobodies against the SARS-CoV-2 spike protein that may be effective at preventing infections. In the current study, the researchers used a slightly different strategy than others to find nanobodies that may work especially well.
Esparza, T.J. et al., High affinity nanobodies block SARS CoV 2 spike receptor binding domain interaction with human angiotensin converting enzyme. Scientific Reports, December 22, 2020 DOI: 10.1038/s41598-020-79036-0
Source: Press release, National Institute of Neurological Disorders and Stroke (NINDS)