Researchers say shark antibodies can prevent the virus that causes COVID-19
Small antibody-like proteins known as VNARs will not be immediately available as a treatment, but they could help prepare for future coronavirus outbreaks
BOSTON — The Cape's seasonal visitor that has sparked fear could actually be the secret weapon to beating back coronavirus outbreaks.
Researchers have found that shark antibodies can prevent the virus that causes COVID-19, its variants and related coronaviruses from infecting human cells.
These small antibody-like proteins known as VNARs — derived from the immune systems of sharks — will not be immediately available as a treatment in people, according to the researchers. However, they can help prepare for future coronavirus outbreaks.
"The big issue is there are a number of coronaviruses that are poised for emergence in humans," said Aaron LeBeau, a University of Wisconsin-Madison professor of pathology.
"What we're doing is preparing an arsenal of shark VNAR therapeutics that could be used down the road for future SARS outbreaks," added LeBeau, who helped lead the study. "It's a kind of insurance against the future."
This potential treatment could be especially important for those with compromised immune systems who do not respond as well to vaccination, and may benefit from other treatments like antibodies.
The shark VNARs were able to neutralize WIV1-CoV, a coronavirus that is capable of infecting human cells but currently circulates only in bats — where SARS-CoV-2, the virus that causes COVID-19, likely originated.
LeBeau and his lab in the School of Medicine and Public Health collaborated with researchers at the University of Minnesota and Elasmogen, a biomedical company in Scotland that's developing therapeutic VNARs.
One-tenth the size of human antibodies, the shark VNARs can bind to infectious proteins in unique ways that bolster their ability to halt infection.
"These small antibody-like proteins can get into nooks and crannies that human antibodies cannot access," LeBeau said.
"This allows them to recognize structures in proteins that our human antibodies cannot," he added.
The researchers tested the shark VNARs against both infectious SARS-CoV-2 and a "pseudotype," a version of the virus that can't replicate in cells. They identified three candidate VNARs from a pool of billions that effectively stopped the virus from infecting human cells.
The three shark VNARs were also effective against SARS-CoV-1, which caused the first SARS outbreak in 2003.
This research was conducted before the new highly contagious omicron variant was discovered, but initial models suggest the VNAR would remain effective against this new version, LeBeau said.
Future therapies would likely include a cocktail of multiple shark VNARs to maximize their effectiveness against diverse and mutating viruses. This new class of drug is cheaper and easier to manufacture than human antibodies, according to the researchers.
LeBeau is also studying the ability of shark VNARs to help in the treatment and diagnosis of cancers.
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