Genetically engineering mice to make their immune system human is not a new invention. But a team of researchers from Harvard Medical School has now created a special line of new effective antibodies once morest the Sars coronavirus 2 through a complex combination of human and mouse genes. As the team around Sai Luo, Jun Zhang and Alex Kreutzberger reported in the magazine Science Immunology, the SP1-77 abbreviated antibody was not only able to switch off all previously known variants of Corona, including all omicron subvariants up to BA.5, but it also used one new mechanism.
New antibody can interrupt virus-cell fusion
Antibodies to date, whether produced by vaccination or supplied externally as genetically engineered monoclonal antibodies, have usually worked by attaching themselves to what is known as the receptor-binding domain (RBD) of the virus. This is the part of the virus that can attach itself to the host cells. Once this attachment is complete, a process is set in motion in which the virus first attaches itself further to the surface of the host cell and finally fuses its envelope with this surface. The genetic information of the virus is practically catapulted into the human cell.
Apparently, the SP1-77 antibody can prevent exactly this process of the fusion of both envelopes. On the one hand, it attaches itself to the receptor-binding domain (RBD), but on the other hand it also touches part of the N-subunit of the spike protein. And it can apparently prevent the S1 subunit of the spike protein from being dissolved following it has attached to the cell. However, this dissolution is an important step in the process of merging. If it can be blocked, the whole fusion is blocked and the virus is no longer able to infect the cell.
