Much is said about the immune system of sharks. Among other things, fish didn’t have to be cancerous, which is why a ferocious shark cartilage business began. it was just superstition, A tiny component of a shark’s body’s defenses could perhaps help us in the fight against coronavirus in the future: tiny antibody-like proteins, so-called VNARs, that prevent coronaviruses from infecting human cells. This is what Aaron LeBeau from the University of Wisconsin-Madison and his team in “Nature Communications” report., However, there is still a long way to go before clinical application.
Proteins specific for Sars-CoV2 were isolated from large synthetic VNAR libraries from Elasmogen, a Scottish biomedical company specializing in the development of therapeutic VNARs. These shark proteins are significantly smaller than human antibodies, but can bind to infectious particles and render them harmless.
The team also tested the shark VNAR against a “pseudotype,” a version of the virus that cannot multiply in cells. From a pool of billions of VNARs, it eventually identified three candidates that were effective in preventing the virus from infecting human cells. The three variants also rendered harmless Sars-CoV-1, which triggered the first Sars outbreak in 2003.
The study once again focused on the virus’s spike protein, which it uses to bind to human cells. One of the three VRANs blocks this binding process at a very specific point and thus prevents the virus from entering the cell. This region is very similar in genetically different coronaviruses, so that a protein called 3B4 can also effectively neutralize the Mers virus, which has also spread from camels to humans and has caused severe disease.
