Promising Multivalent Single Domain Antibodies Against COVID-19 Infection
Posted: Mar 15, 2021
COVID-19 pandemic predominantly hits countries all over the world and has continued causing panic ever since the end of 2019. Due to the emerging coronavirus variants and mutations, a new treatment to block SARS-CoV-2 infection is the most concerning issue for medical personnel and pharmaceutic companies.
In collaboration with scientists in Germany and the U.S., researchers at Karolinska Institutet in Sweden recently conducted a study and developed a novel small antibody (aka nanobodies). It’s a kind of single-domain antibodies (sdAbs) that is potential to be a SARS-CoV-2 prevention.
How Multivalent Single Domain Antibodies Work Against SARS-CoV-2?
SARS-CoV-2 infects the host cells by spike proteins on its surface. Therefore, the key is to prevent SARS-CoV-2 spike proteins from binding to the attacked cell, which could be realized by certain antibodies.
Researchers obtained antibodies that can block SARS-CoV-2 and simple antibody variants from alpaca and llamas to develop the single-domain antibodies.
After sampling and further analysis, four single-domain antibodies out of millions of antibodies show promising ability to prevent virus infection and spread among the cultured human cells.
Usually, spike protein on the virus will change the structure for the fusion of virus envelope and cell membrane. But before the pathogen binds to the target cells, single-domain antibodies trigger this structural change and prevent the virus from binding to the host cell, and consequently, stop the infection.
Why Multivalent Single Domain Antibodies is a Promising COVID-19 Treatment?
The superiority of single-domain antibodies against COVID-19 is mainly reflected in many aspects.
sdAbs are small antibody fragments that are smaller than regular antibodies, meaning a simpler producing process with lower costs. Moreover, those antibody fragments also enjoy privilege when binding to the virus’ surface and interrupt virus infection because they are small enough to access more places.
What’s more, single-domain antibodies are stable even in extreme environments and can be easily produced by bacteria or yeast on a large scale.
For instance, Creative Biolabs, one of the most competent single-domain antibody services providers, has supplied comprehensive and cost-effective single-domain antibody services for years. Creative Biolabs can develop desired sdAb by employing different targets when immunizing camel, llama, alpaca or even shark. The single-domain antibody services at Creative Biolabs include, but are not limited to production and discovery.
But the real amazing point is that researchers stitched two single-domain antibodies and made it a new molecule, multivalent single-domain antibody. That’s to say, the combined single-domain antibodies can bind to two different places simultaneously on the spike proteins of the virus. As a result, such sdAbs attack the virus more efficiently and significantly lower the risk that the virus mutates rapidly to resist the new combined molecules.
This extraordinary study has been published in Science, indicating multivalent single-domain antibodies may have a good effect to attack the virus even if it’s mutated.
Now, the research group at Karolinska Institutet believes that these multivalent single-domain antibodies are highly potential to be developed into a novel and effective treatment and a promising COVID-19 vaccine candidate. Hopefully, this treatment plan could be applied to patients who have already been infected, and those who can’t respond to vaccine due to immunodeficiency or can’t accept vaccination at all.
Anyhow, once the new treatment or drugs of multivalent single-domain antibodies is put into practice and it shows a positive effect, it would be a great relief to the current coronavirus pandemic.
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