Chinese scientists have found that the new coronavirus SARS-CoV-2 can penetrate into human cells not only through the receptor protein ACE2, as previously thought, but the other way is through the growth of protein molecules CD147. This is an important result, which will help to create a more efficient and safe vaccine. The study is published in the library of preprints and bioRxiv.
It was believed that the coronavirus SARS-CoV-2 that causes disease COVID-19 penetrates into human cells using ACE2 protein, so the basic strategy in the development of a vaccine against the new coronavirus has been focused on the inhibitors of ACE2 or the formation of immune response to this protein.
But ACE2 plays an important role in the body, being present in the cells of the lungs, heart, kidneys and reproductive system, so attempt to cope with the virus through this protein can negatively affect the work of these bodies.
Now Chinese biologists from the Fourth medical military University in XI’an and the Institute of biotechnology in Beijing found another route of entry of SARS-CoV-2 in human cells, which opens up for scientists additional capabilities in dealing with the coronavirus.
“We know that the penetration into the body, the virus uses the receptor ACE2. We have identified another receptor, the molecules of which attacks the virus. This extends the possible range of means to suppress the infection,” the authors write in the article.
The researchers noticed that the virus SARS-COV-2 binds to CD147 molecules — receptors on the cell surface, which are used for penetration of some other viral infection and Plasmodium malaria.
Protein CD147 (cluster of differentiation 147), also known as basigin (BSG) or extracellular inducer of matrix metalloproteinase (EMMPRIN) belongs to the superfamily of immunoglobulins that are present in human blood.
Binding of the coronavirus with CD147 occurs through the so-called spiculae proteins spinous outgrowths on the surface of the virus. Earlier this way was proven for another coronavirus SARS-CoV, the causative agent of acute respiratory syndrome SARS, also known as atypical pneumonia.
Researchers treated the cell culture in vitro lung antibodies contained in the substance malasoma that block CD147 work, and tried to infect these cells by the coronavirus SARS-CoV-2. Even a small concentration of antibody was sufficient to completely stop the spread of the virus in the cells. Research using immunoelectron microscopy confirmed at the molecular level, the fusion shell of coronavirus and CD147.
The results show that existing drugs to fight malaria and SARS may be effective against the new coronavirus.