Scientists engineer decoy protein
Scientists have engineered a decoy protein which binds to the novel coronavirus and blocks infection in cultured cells, an advance that may lead to a therapeutic or preventive agent against COVID-19. According to the researchers, including Erik Procko from the University of Illinois, Urbana-Champaign in the US, in order to infect a human cell, a virus must first bind to a receptor protein on the surface of the cell.
- For the novel coronavirus SARS-CoV-2, they said this happens via a receptor protein called ACE2, which is found particularly in tissues in the lungs, heart, arteries, kidneys and intestines, playing a number of roles, including the regulation of blood pressure and inflammation.
- In the study, published in the journal Science, the researchers produced more than 2,000 mutant versions of ACE2 and analysed how these interacted with the coronavirus.
- They found that a combination of three mutations produced a receptor that bound to the virus 50 times more strongly, making it a much more attractive target for the virus than the human body's own version of ACE2.
- When the scientists tested a soluble version of the newly engineered receptor, they found that when it is detached from cells, it is free to interact with the virus as a decoy receptor.
- Administering a decoy based on ACE2 might not only neutralise infection, but may have the additional benefit of rescuing lost ACE2 activity and directly treating aspects of COVID-19.
- According to the scientists, the strong affinity between the virus and the decoy receptor, rivals that of the best antibodies identified to date.
- The scientists found that the decoy receptor not only binds to the virus in live tissue cultures, but it also effectively neutralises it, preventing cells from becoming infected.
- However, they noted that further research is required to determine whether the decoy receptors could be an effective treatment agent against COVID-19.
- Since the decoy protein closely resembles the ACE2 receptor, future studies assessing if it interferes with the body's blood pressure regulation process are needed to evaluate its safety in humans.