PARIS, Mar. 28 (Benin News) –
Researchers at the Karolinska Institute in Sweden have developed a novel strategy to identify potent miniature antibodies, called nanobodies, against emerging variants of SARS-CoV-2. This method has led to the discovery of multiple antibodies that, in cell culture and in mice, effectively block infection by different variants of SARS-CoV-2. These findings, described in the journals Nature Communications and Science Advances, could pave the way for new treatments for COVID-19.
“Using advanced laboratory techniques, we were able to identify a panel of nanobodies that very effectively neutralized several SARS-CoV-2 variants,” says Gerald McInerney, professor in the Department of Microbiology, Tumor and Cell Biology (MTC). from the Karolinska Institute and co-lead author of both studies.
Despite the deployment of vaccines and antivirals, the need for effective therapeutics against severe COVID-19 infection remains high. Nanobodies – which are antibody fragments that occur naturally in camelids and can be adapted to humans – are promising therapeutic candidates, as they offer several advantages over conventional antibodies. For example, they have favorable biochemical properties and are easy to produce at scale and cost-effectively.
In just-published studies, the labs of Gerald McInerney and Ben Murrell, also at MTC, identified several potent nanobodies derived from an alpaca immunized with SARS-CoV-2 antigens.
The first report, published in “Nature Communications”, describes a unique nano-organism, Fu2, which significantly reduces the viral load of SARS-CoV-2 in cell cultures and in mice. Using cryo-electron microscopy, the researchers found that Fu2 naturally binds to two distinct sites on the viral spike, inhibiting the virus’s ability to enter the host cell. This part of the study was carried out in collaboration with Hrishikesh Das and Martin Hällberg from the Department of Cellular and Molecular Biology at the Karolinska Institute.
The researchers then delved into the alpaca’s repertoire of nanobodies by combining a series of advanced laboratory techniques and computational methods, resulting in a library of nanobodies described in detail.
The results, presented in the journal “Science Advances”, revealed the existence of other antibodies which, in cell cultures and in mice, effectively neutralize the founder and beta variants of SARS-CoV-2, and even neutralize the SARS-CoV-1, further away.
“These nanobodies represent promising therapeutic candidates against several SARS-CoV-2 variants,” says first author Leo Hanke, a postdoctoral researcher who developed the nanobody technology in McInerney’s group.
Researchers are now applying the same techniques to identify which nanobodies from this set are most capable of neutralizing omicron, the currently dominating variant of SARS-CoV-2.
“Once established, these libraries can be expanded and searched to find antibodies that neutralize newly emerging variants,” says Associate Professor Ben Murrell, also co-lead author of both studies.