Shark antibody-like protein can neutralize COVID-19 virus

According to a new study published on December 16, small, unique antibody-like proteins called VNARs—from the shark’s immune system—can prevent the virus that causes COVID-19, its variants, and related coronavirus infections Human cells

The new VNARs will not be used for human treatment immediately, but they can help prepare for future coronavirus outbreaks

If these viruses can be transmitted to humans, the development of treatments for these animal-borne viruses in advance may prove useful

Aaron LeBeau, a professor of pathology at the University of Wisconsin-Madison, who led the study, said: “The biggest problem is that there are many coronaviruses that are preparing to infect humans

LeBeau and his laboratory at the School of Medicine and Public Health collaborated with researchers at the University of Minnesota and Elasmogen, a Scottish biomedical company that is developing therapeutic VNARs

VNAR against SARS-CoV-2 was isolated from Elasmogen's large synthetic VNAR library

"These small antibody-like proteins can enter the corners and crevices where human antibodies cannot enter," Le Bosch said

Researchers tested shark VNARs to fight the infectious SARS-CoV-2 and a "pseudotype" virus, which is a virus that cannot replicate in cells

A VNAR named 3B4 is firmly attached to the groove of the viral spike protein, close to where the virus binds to human cells, and seems to prevent this attachment process

3B4's ability to combine these conserved regions in different coronaviruses makes it an attractive candidate against viruses that have not yet infected humans

Among the significant variants of SARS-CoV-2, such as delta variants, the 3B4 binding site is also unchanged

The second most powerful shark VNAR, 2C02, seems to lock the spike protein into an inactive form

Caroline Barelle, CEO of Elasmogen, said: "What is exciting is that these new potential anti-SARS-CoV-2 drug molecules have a different mechanism of action compared with other biologics and antibodies against this virus

Future treatments may include cocktail therapy of multiple shark VNARs to maximize their effectiveness against different and mutant viruses

Vaccines are the cornerstone of the prevention of SARS-CoV-2 and future coronaviruses
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But some people, such as those with compromised immune systems, do not respond as well to vaccines and may benefit from other treatments such as antibodies — making the development of these treatments a current priority
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Mechanisms of SARS-CoV-2 neutralization by shark variable new antigen receptors elucidated through X-ray crystallography