NANOBODIES

Subject: Science & tech

Context: From a llama named Cormac, researchers at the US National Institutes of Health (NIH) have isolated a set of tiny antibodies, or “nanobodies”, that hold promise against the novel coronavirus SARS-CoV-2.

Concept:

• At least one of these nanobodies could prevent infections and detect virus particles by grabbing hold of SARS-CoV-2 spike proteins, the researchers suggest in the journal Scientific Reports.
• This nanobody, called NIH-CoVnb-112, appeared to work equally well in either liquid or aerosol form, which suggests it could remain effective after inhalation.
• 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. They are called nanobodies because they are tiny, about a tenth the weight of most human antibodies.
• Because nanobodies are more stable, less expensive to produce, and easier to engineer than typical antibodies, researchers have been using them for medical research.
• 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, NIH said in a statement.
• The spike protein acts like a key during coronavirus infection. It “unlocks” the door to infections when it binds to a human protein called ACE2 receptor on the cell surface.
• The NIH scientists developed a method that would isolate nanobodies that block infections by covering part of the spike protein that bind to and unlock the ACE2 receptor.