,” says Gerald McInerney, professor at the Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, and joint senior author of both studies.
Despite the roll-out of vaccines and antivirals, the need for effective therapeutics against severe COVID-19 infection remains high.
Nanobodies are fragments of antibodies that occur naturally in camelids and can be used as promising therapeutic candidates due to their several advantages over conventional antibodies.
The first report describes a single nanobody, Fu2 (named after the alpaca Funny), that significantly reduced the viral load of SARS-CoV-2 in cell cultures and mice.
Using electron cryo-microscopy, the researchers found that Fu2 naturally binds to two separate sites on the viral spike, thus inhibiting the virus’ ability to enter the host cell.
Researchers next delved deeper into the alpaca’s nanobody repertoire by combining a range of advanced laboratory techniques and computational methods, resulting in a library of nanobodies described in detail.
They also revealed additional nanobodies that in cell cultures and mice effectively cross-neutralized both the founder and beta variant of SARS-CoV-2 and even neutralized the more distantly related SARS-CoV-1.
Currently, researchers are applying the same techniques to identify which nanobodies from this set are best able to neutralize Omicron, the now dominating SARS-CoV-2 variant.
Once established, these libraries can be expanded and mined for nanobodies that neutralize new emerging variants.
Source: Medindia
