London - A team of researchers has identified a protein that may critically contribute to severe forms of Covid-19.
The research, published in the journal Current Issues in Molecular Biology, found that the infection of cells with SARS-CoV-2 results in increased levels of a protein called CD47 on the cell surface.
CD47 is a so-called 'do not eat me' signal to the immune system's defences that protect cells from being destroyed.
Virus-induced CD47 on the surface of infected cells is likely to protect them from immune system recognition, enabling the production of larger amounts of virus, resulting in more severe disease.
"We may have identified a major factor associated with severe Covid-19. This is a huge step in combatting the disease and we can now look forward to further progress in the design of therapeutics," said researcher Martin Michaelis from the University of Kent.
Well-known risk factors for severe Covid-19 such as older age and diabetes are associated with higher CD47 levels.
High CD47 levels also contribute to high blood pressure, which is a large risk factor for COVID-19 complications such as heart attack, stroke, and kidney disease.
The data suggest that age and virus-induced high CD47 levels contribute to severe Covid-19 by preventing an effective immune response and increasing disease-associated tissue and organ damage.
Since therapeutics targeting CD47 are in development, this discovery may result in improved Covid-19 therapies.