Chinese scientists have found another target for coronavirus SARS-CoV-2 on the surface of human cells. This protein CD147, which, incidentally, is not only the previous coronavirus, the causative agent of atypical pneumonia, but the malaria Plasmodium. By blocking this protein, the researchers were able to stop the spread of the virus in cell culture. Clinical trials of the relevant drug-blocker has already begun. Work published on the portal preprints and bioRxiv.
A cure for the coronavirus SARS-CoV-2 you can search in different ways: for example, try to forbid him to multiply inside cells or to stimulate cell protection. But there is another way — to block the way the virus inside the cells.
The attack of the virus on the target begins with the fact that it sticks its surface proteins to proteins on the cell membrane. Then the membrane of the virus merges with the cell, and the contents of the virus particle (RNA genome) is inside the cell. Until now it was thought that SARS-CoV-2, like its predecessor, SARS-CoV, the causative agent of atypical pneumonia, is better associated with a cellular protein ACE2. However, the new coronavirus as many as four surface protein, so it is logical to assume that the targets, i.e. the points of binding with the cell, it will be a few.
Wang ke (Ke Wang), together with colleagues from the Fourth military medical University in XI’an described another such “door” inside the cell that can be used by SARS-CoV-2. In 2005, after the SARS outbreak, they noticedthat SARS-CoV can bind to a receptor CD147 on the cell surface. It is a protein from the family of immunoglobulins. Apparently, he has several functions: for example, he runs the work of metalloproteinases proteins, rebuilds extracellular substance in the tissues. Since the previous target АСЕ2, the two viruses turned out to be total, they suggested that the new coronavirus also be in contact with CD147.
To test this, the researchers infected with the coronavirus cell culture the human kidney. Then they worked on her antibodies to CD147 was measured and the number of damaged cells and the concentration of viral genomes in culture medium. It turned out that when the concentration of antibody at 3 ug/ml achieved one hundred percent stop the spread of the virus between cells.
Then the authors showed by immunofluorescence analysis that the surface protein of the coronavirus SP and CD147 can interact with each other. And, finally, stained cells infected with coronavirus, antibodies to these proteins. Within SP cells, and CD147 were close, which confirms the assumption that CD147 may help the virus to penetrate cells.